Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery...Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear.In the present study,we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells.We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury,decreased expression of the microglial pyroptosis markers NLRP3,GSDMD,caspase-1,and interleukin-1β,promoted axonal and myelin regeneration,and inhibited the formation of glial scars.In addition,in a lipopolysaccharide-induced BV2 microglia model,conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway.These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway,thereby promoting the recovery of neurological function after spinal cord injury.Therefore,conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.展开更多
Soybean(Glycine max)stands as a globally significant agricultural crop,and the comprehensive assembly of its genome is of paramount importance for unraveling its biological characteristics and evolutionary history.Nev...Soybean(Glycine max)stands as a globally significant agricultural crop,and the comprehensive assembly of its genome is of paramount importance for unraveling its biological characteristics and evolutionary history.Nevertheless,previous soybean genome assemblies have harbored gaps and incompleteness,which have constrained in-depth investigations into soybean.Here,we present Telomere-to-Telomere(T2T)assembly of the Chinese soybean cultivar Zhonghuang 13(ZH13)genome,termed ZH13-T2T,utilizing PacBio Hifi and ONT ultralong reads.We employed a multi-assembler approach,integrating Hifiasm,NextDenovo,and Canu,to minimize biases and enhance assembly accuracy.The assembly spans 1,015,024,879 bp,effectively resolving all 393 gaps that previously plagued the reference genome.Our annotation efforts identified 50,564 high-confidence protein-coding genes,707 of which are novel.ZH13-T2T revealed longer chromosomes,421 not-aligned regions(NARs),112 structure variations(SVs),and a substantial expansion of repetitive element compared to earlier assemblies.Specifically,we identified 25.67 Mb of tandem repeats,an enrichment of 5S and 48S rDNAs,and characterized their genotypic diversity.In summary,we deliver the first complete Chinese soybean cultivar T2T genome.The comprehensive annotation,along with precise centromere and telomere characterization,as well as insights into structural variations,further enhance our understanding of soybean genetics and evolution.展开更多
Offline reinforcement learning(RL)aims to learn policies entirely from passively collected datasets,making it a data‐driven decision method.One of the main challenges in offline RL is the distribution shift problem,w...Offline reinforcement learning(RL)aims to learn policies entirely from passively collected datasets,making it a data‐driven decision method.One of the main challenges in offline RL is the distribution shift problem,which causes the algorithm to visit out‐of‐distribution(OOD)samples.The distribution shift can be mitigated by constraining the divergence between the target policy and the behaviour policy.However,this method can overly constrain the target policy and impair the algorithm's performance,as it does not directly distinguish between in‐distribution and OOD samples.In addition,it is difficult to learn and represent multi‐modal behaviour policy when the datasets are collected by several different behaviour policies.To overcome these drawbacks,the au-thors address the distribution shift problem by implicit policy constraints with energy‐based models(EBMs)rather than explicitly modelling the behaviour policy.The EBM is powerful for representing complex multi‐modal distributions as well as the ability to distinguish in‐distribution samples and OODs.Experimental results show that their method significantly outperforms the explicit policy constraint method and other base-lines.In addition,the learnt energy model can be used to indicate OOD visits and alert the possible failure.展开更多
The semiclassical non-perturbative atomic orbital close-coupling approach has been employed to study the electron capture and excitation processes in He^(2+)-H(1s)and He^(2+)-H(2s)collision systems.In order to ensure ...The semiclassical non-perturbative atomic orbital close-coupling approach has been employed to study the electron capture and excitation processes in He^(2+)-H(1s)and He^(2+)-H(2s)collision systems.In order to ensure the accuracy of our calculated cross sections,a large number of high excited states and pseudostates are included in the expansion basis sets which are centered on the target and projectile,respectively.The total and partial charge transfer and excitation cross sections are obtained for a wide-energy domain ranging from 1 keV/amu to 200 keV/amu.The present calculations are also compared with the results from other theoretical methods.These cross section data are useful for the investigation of astrophysics and laboratory plasma.展开更多
Background Compared with traditional biomagnetic field detection devices,such as superconducting quantum interference devices(SQUIDs)and atomic magnetometers,only giant magneto impedance(GMI)sensors can be applied for...Background Compared with traditional biomagnetic field detection devices,such as superconducting quantum interference devices(SQUIDs)and atomic magnetometers,only giant magneto impedance(GMI)sensors can be applied for unshielded human brain biomagnetic detection,and they have the potential for application in next-generation wearable equipment for brain-computer interfaces(BCIs).Achieving a better GMI sensor without magnetic shielding requires the stimulation of the GMI effect to be maximized and environmental noise interference to be minimized.Moreover,the GMI effect stimulated in an amorphous filament is closely related to its working point,which is sensitive to both the external magnetic field and the drive current of the filament.Methods In this paper,we propose a new noise reducing GMI gradiometer with a dual-loop self-adapting structure.Noise reduction is realized by a direction-flexible differential probe,and the dual-loop structure optimizes and stabilizes the working point by automatically controlling the external magnetic field and drive current.This dual-loop structure is fully program controlled by a micro control unit(MCU),which not only simplifies the traditional constant parameter sensor circuit,saving the time required to adjust the circuit component parameters,but also improves the sensor performance and environmental adaptation.Results In the performance test,within 2 min of self-adaptation,our sensor showed a better sensitivity and signal-to-noise ratio(SNR)than those of the traditional designs and achieved a background noise of 12 pT/√Hz at 10 Hz and 7pT/√Hz at 200 Hz.Conclusion To the best of our knowledge,our sensor is the first to realize self-adaptation of both the external magnetic field and the drive current.展开更多
BACKGROUND ： Many experimental results have been found in previous studies on whether laterality of brain cingulate gyrus exists in processing Chinese words information. OBJECTIVE ： To observe the function of right ...BACKGROUND ： Many experimental results have been found in previous studies on whether laterality of brain cingulate gyrus exists in processing Chinese words information. OBJECTIVE ： To observe the function of right anterior cingulate gyrus and activation showed by MRI in processing Chinese words in a visual working memory judgment tasks, and evaluate the laterality of activated brain regions. DESIGN ： Observation experiment SETTING ： The Medical Psychological Research Center, Second Xiangya Hospital of Central South University.PARTICIPANTS： Thirteen healthy volunteers （7 males and 6 females）, aged （29±7）years ranging from 23 to 36 years old, participated in this fMRI study dunng August 2003 to Febuary 2004. They gave informed consent in accordance with guidelines set by Second Xiangya Hospital of Central South University. All subjects were native Chinese speakers and strongly right handed. METHODS ： In this study, Chinese numeral words were used as test materials and test mode of Sternberg was used in cognitive task, it was aimed to investigate the encephalic region involved in the storage and processing of Chinese numerical information. ①The head of subject was fixed with dense foam pad. Visual working task was performed according to the requests. Verbal working task was that the subject saw target items for four numerals written in Chinese, presenting for 1.5 s and then, after a short time by blank for 3.0 s. The subject saw one numeral presenting for 1.5 s and had to press one button if it was one of the shown numbers and another button if it did not belong to the presented numbers. There were two visual working memory stimuli in each stimulation block. The experiment was conducted in a single run, which consisted of seven blocks of visual working memory tasks. Different Chinese numerals were displayed in each block to avoid any practice effect （The response rate of the whole working memory task was 50%）. ②The activation of brain was scanned with a 1.5T MRI scanner （GE Signa Twinspeed） （slice thickness 5 mm, slice gap 1.5 mm, slice parallel to line between pars geniculate and splenium in corpus callosum from corona capitis to superior part of cerebellum, totally 16 to 18 layers）. ③The obtained images were pre-processed and statistically analysed with SPM 99 software. The procedure included timeslice adjusted, realigned, nomalized and smoothed, According to experimental task, data from each subject were analysed to obtain t value of each voxel. Brain activation image was got by Student＇s t test and statistic was presented by pseudo-color. Statistical parameter image was formed by overlapping brain activation image on three-dimensional structure image, and the threshold value was set at P〈 0.05 with ten or more continous voxels （T ≥ 4.64, K ≥ 10 voxels）. The brain activation images of all the subjects were calculated and overlapped into mean brain activation images. The regions with different activation density were found out. The activation voxels in regions-of-interest were checked to calculate a laterality index for each condition. The negative value indicated right hemisphere dominance. MAIN OUTCOME MEASURES ： fMRI activation and laterality coefficient of Chinese numedal working task.RESULTS： Thirteen healthy subjects participated in the result analysis. ①fMRI activation of Chinese numerial working task： The results showed that the working memory task with Chinese words not only activated left cerebral cortex including left superior frontal gyrus （BA6/10）, left middle frontal gyrus （BA9）, left inferior frontal gyrus （BA45/9/47）, but also activated right cerebral cortex including right middle frontal gyrus （BA10/46/8）, right inferior frontal lobe （BA47）. Specially, peak activation was located in right anterior cingulate gyrus （BA32） with an activation volume of 879 （voxels）. It indicated that superior, middle and inferior frontal gyrus, bilateral Broca regions and anterior cingutate involved in the working memory of Chinese words. ②Asymmertry index ： The asymmetry index was -0.47 for frontal lobe, ＋0.42 for temporal lobe, ＋0.14 for parietal lobe and -1.00 for occipital lobe. It indicated that the right frontal lobe, left temporal lobe, left parietal lobe and dght occipital lobe were more involved in the Chinese numedal working task.展开更多
Image-guided thermal ablation(TA),which is less invasive,has been widely applied for treating various kinds of tumors.However,TA still poses the potential risk of thermal damage to sensitive tissue nearby.Therefore,an...Image-guided thermal ablation(TA),which is less invasive,has been widely applied for treating various kinds of tumors.However,TA still poses the potential risk of thermal damage to sensitive tissue nearby.Therefore,an adjunctive thermoprotective hydrodissection technique with constant injection of 5%glucose(5%Glu)has currently been adopted for clinical application,but this may be hazardous to humans.In this study,a multifunctional hyaluronic acid-based hydrogel(HA-Dc)was developed for hydrodissection.Compared with 5%Glu(the most clinically used solution)and the previously reported F127 hydrogel,the HA-Dc hydrogel was studied in vitro in a porcine liver model and in vivo in a rabbit model and showed good injectability and better tissue retention,stability,and thermoprotective properties throughout the TA procedure.Furthermore,in the preclinical evaluation in a Macaca fascicularis(M.fascicularis)model,HA-Dc showed excellent performance in terms of stricter neuroprotection compared with 5%Glu.In addition,the HA-Dc hydrogel with good biocompatibility and controllable degradation behavior in vivo could be a promising platform for thermal protection during clinical TA procedures.展开更多
Nanomaterial-mediated phototherapy in tumor treatment has been developed rapidly in the past few years due to its noninvasive character.However,the low energy conversion efficiency and high recombination rate of the p...Nanomaterial-mediated phototherapy in tumor treatment has been developed rapidly in the past few years due to its noninvasive character.However,the low energy conversion efficiency and high recombination rate of the photo-triggered electron–hole pairs of single nano-agent limit the phototherapy efficiency.Herein,we constructed a novel two-dimensional nanoheterojunction MoS_(2)-Ti_(3)C_(2)(MT),which allowed a high photothermal conversion efficiency(59.1%)as well as an effective separation of photo-triggered electron–hole pairs for reactive oxygen species(ROS)generation under single 808 nm laser irradiation.Upon the modification of the mitochondrial targeted molecule(3-proxycarboxylic)triphenyl phosphine bromide(TPP)and 4T1 cell membrane,m@MoS_(2)-Ti_(3)C_(2)/TPP(m@MTT)could effectively target to the tumor cell and further locate to the mitochondria to amplify tumor-specific oxidative stress,which not merely effectively inhibits the local tumor growth but also induces tumor immunogenic cell death(ICD)for activating antitumor immune response.Additionally,cytosine guanine dinucleotide(CPG),as a Toll-like receptor 9(TLR9)agonist,was further introduced to the system to boost adaptive immune responses,resulting in improved level of cytotoxic T cells as well as a decrease in the number of regulatory T cells.In vivo antitumor mechanism studies demonstrated that not only the primary and distant tumors in 4T1 bearing-tumor mice model were significantly inhibited,but also the lung metastasis of tumor was effectively suppressed.Therefore,this work revealed the ROS generation mechanism of MT nanoheterojunction and provided a novel strategy to fabricate a biomedically applicable MT nanoheterojunction for tumor treatment.展开更多
The single-line-to-ground faults with line breaks(SLGFs-LBs)occur more and more frequently in distribution networks and can cause major safety accidents.It is difficult to distinguish the single-line-to-ground faults(...The single-line-to-ground faults with line breaks(SLGFs-LBs)occur more and more frequently in distribution networks and can cause major safety accidents.It is difficult to distinguish the single-line-to-ground faults(SLGFs)in resonant grounding systems and ungrounding systems due to the same electrical characteristics on the source side and uncertain operation conditions of distribution networks.This paper proposes a method for distinguishing SLGFs-LBs and SLGFs.First,the source-side and load-side voltage characteristics of SLGFs and SLGFs-LBs are analyzed,and the phase difference between the voltages of the fault phase and non-fault phase on the load side is selected as the identification criterion.Phasor measurement units(PMUs)are selected as measuring devices.Then,the effects of operation conditions and external devices in distribution networks on the proposed method are discussed,and the phase errors caused by them are calculated to correct the identification method.Finally,the field testing and simulation experiments are conducted to verify the effectiveness and robustness of the proposed method.展开更多
Wearable sweat sensors are becoming increasingly popular for their robust capabilities in non-invasive,dynamic,and continuous real-time monitoring of biological information.Real-time monitoring of large-scale samples ...Wearable sweat sensors are becoming increasingly popular for their robust capabilities in non-invasive,dynamic,and continuous real-time monitoring of biological information.Real-time monitoring of large-scale samples is crucial for realizing intelligent health.A major bottleneck for enabling large-scale sweat elucidation is the fabrication of wearable sensors equipped with microfluidic devices and flexible electrodes in a cost-effective,homogeneous performance and rapid large-scale way.Herein,a“Screen+Wax”-printing technique was introduced to prepare these components and construct“Lego Bricks”type wearable sweat sensor sensor to monitor sweat Na^(+)and K^(+).Flexible electrode arrays and paper-based microfluidic layers(they act as building blocks)were fabricated on polyethylene terephthalate and paper surfaces,respectively,using screen printing and wax printing.Gold nanoparticles and Na^(+)/K^(+)ion-selective membranes were modified on the electrode surfaces by electrodeposition and drop coating,respectively.In this work,we highlight the excellent performance of the“Lego Bricks”type wearable sweat sensor in testing the Na^(+)and K^(+)imbalance of sweat from different body regions during exercise and,more significantly,to track the physical activity during prolonged exercise under different interventions.Furthermore,the prepared“Lego Bricks”wearable sweat ion electrochemical sensor is demonstrated to be capable of large-scale samples elucidation with outstanding performance and costeffectiveness,which is expected to deeply integrate sweat monitoring into physical activity,providing an important tool for intelligent health.展开更多
Weather-related failures significantly challenge the reliability of distribution systems. To enhance the risk management of weather-related failures, an interpretable extra-trees based weather-related risk prediction ...Weather-related failures significantly challenge the reliability of distribution systems. To enhance the risk management of weather-related failures, an interpretable extra-trees based weather-related risk prediction model is proposed in this study. In the proposed model, the interpretability is successfully introduced to extra-trees by analyzing and processing the paths of decision trees in extra-trees. As a result, the interpretability of the proposed model is reflected in the following three respects: it can output the importance, contribution, and threshold of weather variables at high risk. The importance of weather variables can help in developing a long-term risk prevention plan. The contribution of weather variables provides targeted operation and maintenance advice for the next prediction period. The threshold of weather variables at high risk is critical in further preventing high risks. Compared with the black-box machine learning risk prediction models, the proposed model overcomes the application limitations. In addition to generating predicted risk levels, it can also provide more guidance information for the risk management of weather-related failures.展开更多
Computer vision is a field that involves making a machine “see”.This technology uses a camera and computer instead of the human eye to identify,track and measure targets for further image processing.With the develop...Computer vision is a field that involves making a machine “see”.This technology uses a camera and computer instead of the human eye to identify,track and measure targets for further image processing.With the development of computer vision,such technology has been widely used in the field of agricultural automation and plays a key role in its development.This review systematically summarizes and analyzes the technologies and challenges over the past three years and explores future opportunities and prospects to form the latest reference for researchers.Through the analyses,it is found that the existing technology can help the development of agricultural automation for small field farming to achieve the advantages of low cost,high efficiency and high precision.However,there are still major challenges.First,the technology will continue to expand into new application areas in the future,and there will be more technological issues that need to be overcome.It is essential to build large-scale data sets.Second,with the rapid development of agricultural automation,the demand for professionals will continue to grow.Finally,the robust performance of related technologies in various complex environments will also face challenges.Through analysis and discussion,we believe that in the future,computer vision technology will be combined with intelligent technology such as deep learning technology,be applied to every aspect of agricultural production management based on large-scale datasets,be more widely used to solve the current agricultural problems,and better improve the economic,general and robust performance of agricultural automation systems,thus promoting the development of agricultural automation equipment and systems in a more intelligent direction.展开更多
Owing to excellent conductivity and abundant surface terminals,MXene-based heterostructures have been intensively investigated as energy storage materials.However,elaborate design of the structure and composition of M...Owing to excellent conductivity and abundant surface terminals,MXene-based heterostructures have been intensively investigated as energy storage materials.However,elaborate design of the structure and composition of MXene-based hybrids towards superior electrochemical performance is still challenging.Herein,we present an ingenious leaf-inspired design for preparing a unique Sb_(2)S_(3)/nitrogen-doped Ti_(3)C_(2)T_(x)MXene(L-Sb_(2)S_(3)/Ti_(3)C_(2))hybrid.In-situ TEM observations reveal that the leaflike Sb_(2)S_(3)nanoparticles with numerous mesopores can well relieve the large volume changes via an inward pore filling mechanism with only 20%outward expansion,whereas highly conductive N-doped Ti_(3)C_(2)T_(x)nanosheets can serve as the robust mechanical support to reinforce the structural integrity of the hybrid.Benefiting from the structural and constituent merits,the L-Sb_(2)S_(3)/Ti_(3)C_(2)anode fabricated exhibits a fast sodium storage behavior in terms of outstanding rate capability(339.5 mA h g^(-1)at 2,000 mA g^(-1))and high reversible capacity at high current density(358.2 mA h g^(-1)at 1,000 mA g^(-1)after 100 cycles).Electrochemical kinetic tests and theoretical simulation further manifest that the boosted electrochemical performance mainly arises from such a unique leaf-like Sb_(2)S_(3)mesoporous nanostructure with abundant active sites,and enhanced Na^(+)adsorption energy on the heterojunction formed between Sb_(2)S_(3)nanoparticles and Ti_(3)C_2)matrix.展开更多
The harvesting of fresh kiwifruit is a labor-intensive operation that accounts for more than 25%of annual production costs.Mechanized harvesting technologies are thus being developed to reduce labor requirements for h...The harvesting of fresh kiwifruit is a labor-intensive operation that accounts for more than 25%of annual production costs.Mechanized harvesting technologies are thus being developed to reduce labor requirements for harvesting kiwifruit.To improve the efficiency of a harvesting robot for picking kiwifruit,we designed an end-effector,which we report herein along with the results of tests to verify its operation.By using the established method of automated picking discussed in the literature and which is based on the characteristics of kiwifruit,we propose an automated method to pick kiwifruit that consists of separating the fruit from its stem on the tree.This method is experimentally verified by using it to pick clustered kiwifruit in a scaffolding canopy cultivation.In the experiment,the end-effector approaches a fruit from below and then envelops and grabs it with two bionic fingers.The fingers are then bent to separate the fruit from its stem.The grabbing,picking,and unloading processes are integrated,with automated picking and unloading performed using a connecting rod linkage following a trajectory model.The trajectory was analyzed and validated by using a simulation implemented in the software Automatic Dynamic Analysis of Mechanical Systems(ADAMS).In addition,a prototype of an end-effector was constructed,and its bionic fingers were equipped with fiber sensors to detect the best position for grabbing the kiwifruit and pressure sensors to ensure that the damage threshold was respected while picking.Tolerances for size and shape were incorporated by following a trajectory groove from grabbing and picking to unloading.The end-effector separates clustered kiwifruit and automatically grabs individual fruits.It takes on average 4–5 s to pick a single fruit,with a successful picking rate of 94.2%in an orchard test featuring 240 samples.This study shows the grabbing–picking–unloading robotic end-effector has significant potential to facilitate the harvesting of kiwifruit.展开更多
The exploration of advanced MoS_(2)-based electrode materials overcoming their inherent low conductivity and large volume changes is of importance for next-generation energy storage.In this work,we report a simple and...The exploration of advanced MoS_(2)-based electrode materials overcoming their inherent low conductivity and large volume changes is of importance for next-generation energy storage.In this work,we report a simple and high-efficient one-pot hydrothermal approach to prepare a unique and stable 1D/2D heterostructure.In the architecture,ultrathin carbon layer-coated MoS_(2) nanosheets with large expanded interlayer of 1.02 nm are vertically grown onto the Ti_(3)C_(2) MXene and cross-linked carbon nanotubes(CNTs),giving rise to a highly conductive 3D network.The interlayer expanded MoS_(2) nanosheets can greatly facilitate the Na ions/electrons transmission.Meanwhile,the N-doped 1D/2D CNTs-Ti_(3)C_(2) matrix can be used as a strong mechanical support to well relieve the large volume expansion upon cycles.As a combination result of several advantages,the developed quaternary C-MoS_(2)/CNTs-Ti_(3)C_(2) composite anode shows an excellent sodium storage performance(562 mA h g^(-1) at 100 mA g^(-1) after 200 cycles)and rate capability(475 mA h g^(-1) at 2000 mA g^(-1)).The density functional theory calculations further prove that the full combination of layer-expanded MoS_(2) nanosheets and N-doped Ti_(3)C_(2) matrix can significantly enhance the adsorption energy of Na ions,further resulting in the enhancement of sodium storage capabilities.展开更多
Layered structure MoS_(2) nanosheets have shown great potential for energy storage applications.However,the methodology for elaborately controllable growth of MoS_(2) onto carbonaceous matrix for promoting the electro...Layered structure MoS_(2) nanosheets have shown great potential for energy storage applications.However,the methodology for elaborately controllable growth of MoS_(2) onto carbonaceous matrix for promoting the electrochemical performance is highly desirable.Herein,a high-effective,all-in-one in-situ conversion growth strategy has been proposed to construct a stable sandwich-type nanostructure.The formation of the optimized C-MoS_(2)/NCNTs product undergoes a dissolution-recrystallization process,in which ultra-thin carbon layer-coated MoS_(2) nanosheets densely assembled onto the surface of polyimide(PI)derived N-doped carbon nanotubes(CNTs).Theoretical simulation reveals that MoS_(2) nanosheets possessing an expanded interlayer spacing of 0.92 nm can greatly reduce the barrier energy of Na ions mitigation.Ac-cordingly,the as-made C-MoS_(2)/NCNTs anode delivers superior cycling stability(82%capacity retention after 400 cycles at 1 A g^(−1))and rate performance(348 mAh g^(−1) at 2 A g^(−1)).The results demonstrate that the expanded MoS_(2) interlayer distance,ultrathin outer carbon coating,and N-doped CNTs matrix together accounts for the outstanding sodium storage capability for the C-MoS_(2)/NCNTs electrode.展开更多
Intelligent perception is the cornerstone of digitalisation of power grid.Due to the closest connection with users,the information perception ability of distribution network directly affects the reliability of power s...Intelligent perception is the cornerstone of digitalisation of power grid.Due to the closest connection with users,the information perception ability of distribution network directly affects the reliability of power supply.Distribution network has a wide range of geographical distribution and equipment types.The application of intelligent perception is with high complexity and dynamics under the limitation of both technology and management.Therefore,the study first sorts out the current application status of intel-ligent perception technology and equipment in distribution network from three appli-cation fields including distribution automation,metering systems,and inspection.Then,the constraints of existing intelligent perception applications and the key points of further research are pointed out.Finally,the development trends of intelligent perception technology in distribution network are presented from the three aspects of basic tech-nology,perception equipment,and advanced applications.With the improvement of sensing,communication,energy acquisition,chips and perception equipments,the depth and breadth of advanced applications in distribution network will be expanded.The research results can provide references for the follow‐up research and practice of intel-ligent perception in distribution networks.展开更多
Although sonodynamic therapy(SDT)is a promising non-invasive tumor treatment strategy due to its safety,tissue penetration depth and low cost,the hypoxic tumor microenvironment limits its therapeutic effects.Herein,we...Although sonodynamic therapy(SDT)is a promising non-invasive tumor treatment strategy due to its safety,tissue penetration depth and low cost,the hypoxic tumor microenvironment limits its therapeutic effects.Herein,we have designed and developed an oxygen-independent,ROS-amplifying chemo-sonodynamic antitumor therapy based on novel pH/GSH/ROS triple-responsive PEG-PPMDT nanoparticles.The formulated artemether(ART)/Fe_(3)O_(4)-loaded PEG-PPMDT NPs can rapidly release drug under the synergistic effect of acidic endoplasmic pH and high intracellular GSH/ROS levels to inhibit cancer cell growth.Besides,the ROS level in the NPs-treated tumor cells is magnified by ART via interactions with both Fe^(2+)ions formed in situ at acidic pH and external ultrasound irradiation,which is not affected by hypoxia tumor microenvironment.Consequently,the enriched intracellular ROS level can cause direct necrosis of ROS-stressed tumor cells and further accelerate the drug release from the ROS-responsive PEG-PPMDT NPs,achieving an incredible antitumor potency.Specifically,upon the chemo-sonodynamic therapy by ART/Fe_(3)O_(4)-loaded PEG-PPMDT NPs,all xenotransplants of human hepatocellular carcinoma(HepG2)in nude mice shrank significantly,and 40% of the tumors were completely eliminated.Importantly,the Fe3O4 encapsulated in the NPs is an efficient MRI contrast agent and can be used to guide the therapeutic procedures.Further,biosafety analyses show that the PEG-PPMDT NPs possess minimal toxicity to main organs.Thus,our combined chemo-sonodynamic therapeutic method is promising for potent antitumor treatment by controlled release of drug and facile exogenous generation of abundant ROS at target tumor sites.展开更多
With the proposed concept of global energy interconnection, half-wavelength alternating current transmission(HWACT) technology becomes of more interest.HWACT lines can be adopted to establish a pointto-grid system, in...With the proposed concept of global energy interconnection, half-wavelength alternating current transmission(HWACT) technology becomes of more interest.HWACT lines can be adopted to establish a pointto-grid system, in which the penetrating power(PP) is produced between receiving terminals, having a significant effect on the power flow distribution.In order to investigate this phenomenon, the PP characteristics of the HWACT system are researched in this paper.First, the mathematical relationship between the transmission power and terminal bus voltages of a single HWACT line is derived using the equations of a distributed parameter model.The research indicates that the relationship between power and terminal voltages shows ‘‘reverse characteristics"opposite to those of regular short transmission lines.Then, the concept and definition of PP in a point-to-grid system with two receiving terminals are proposed, and the corresponding relationship between PP and the terminal bus voltages is derived.Simulations are carried out to validate the theory under different conditions, so that the accuracy and adaptiveness of the theoretical analysis can be proved.In addition, the results demonstrate that selecting the location for a HWACT system has demanding requirements in order to control the value of PP.展开更多
Slurry pipeline transport is widely used in several industrial processes.Calculating the specific power consumption(SPC)and determining the best working conditions are important for the design and operation of transpo...Slurry pipeline transport is widely used in several industrial processes.Calculating the specific power consumption(SPC)and determining the best working conditions are important for the design and operation of transportation systems.Based on the Shanghai Jiao Tong University high-concentration multi-sized slurry pressure drop(SJTU-HMSPD)pipeline-resistance-calculation model,the SJTU-SPC model for calculating the power required to transport a unit volume of solid materials over a unit pipeline length is established for a slurry transport system.The said system demonstrates a uniformity coefficient in the 1.26–7.98 range,median particle size of 0.075–4 mm,particle volume concentration of 10–60%,and pipeline diameter of 0.203–0.8 m.The results obtained were successfully verified against existing experimental data.The influence of parameters,such as particle-gradation uniformity coefficient,median particle size,pipe diameter,and particle volume concentration,on the SPC were analysed.The results revealed that the greater is the uniformity coefficient,the smaller is the minimum specific energy consumption and the larger the optimal transport concentration for a constant,median particle size slurry.As observed,the optimal transport concentration for broad-graded sand equalled approximately 48%.These results supplement the conclusions of existing research,indicating that the optimal transport concentration is approximately 30%and provides theoretical support for high concentration transportation of broad graded slurry.展开更多
基金supported by the Research Foundation of Technology Committee of Tongzhou District,No.KJ2019CX001(to SX).
文摘Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear.In the present study,we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells.We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury,decreased expression of the microglial pyroptosis markers NLRP3,GSDMD,caspase-1,and interleukin-1β,promoted axonal and myelin regeneration,and inhibited the formation of glial scars.In addition,in a lipopolysaccharide-induced BV2 microglia model,conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway.These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway,thereby promoting the recovery of neurological function after spinal cord injury.Therefore,conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.
基金This work has been supported by the National Key Research and Development Program of China(2021YFF1200105)National Natural Science Foundation of China(62172125,62371161).
文摘Soybean(Glycine max)stands as a globally significant agricultural crop,and the comprehensive assembly of its genome is of paramount importance for unraveling its biological characteristics and evolutionary history.Nevertheless,previous soybean genome assemblies have harbored gaps and incompleteness,which have constrained in-depth investigations into soybean.Here,we present Telomere-to-Telomere(T2T)assembly of the Chinese soybean cultivar Zhonghuang 13(ZH13)genome,termed ZH13-T2T,utilizing PacBio Hifi and ONT ultralong reads.We employed a multi-assembler approach,integrating Hifiasm,NextDenovo,and Canu,to minimize biases and enhance assembly accuracy.The assembly spans 1,015,024,879 bp,effectively resolving all 393 gaps that previously plagued the reference genome.Our annotation efforts identified 50,564 high-confidence protein-coding genes,707 of which are novel.ZH13-T2T revealed longer chromosomes,421 not-aligned regions(NARs),112 structure variations(SVs),and a substantial expansion of repetitive element compared to earlier assemblies.Specifically,we identified 25.67 Mb of tandem repeats,an enrichment of 5S and 48S rDNAs,and characterized their genotypic diversity.In summary,we deliver the first complete Chinese soybean cultivar T2T genome.The comprehensive annotation,along with precise centromere and telomere characterization,as well as insights into structural variations,further enhance our understanding of soybean genetics and evolution.
基金National Natural Science Foundation of China,Grant/Award Number:U19A2083。
文摘Offline reinforcement learning(RL)aims to learn policies entirely from passively collected datasets,making it a data‐driven decision method.One of the main challenges in offline RL is the distribution shift problem,which causes the algorithm to visit out‐of‐distribution(OOD)samples.The distribution shift can be mitigated by constraining the divergence between the target policy and the behaviour policy.However,this method can overly constrain the target policy and impair the algorithm's performance,as it does not directly distinguish between in‐distribution and OOD samples.In addition,it is difficult to learn and represent multi‐modal behaviour policy when the datasets are collected by several different behaviour policies.To overcome these drawbacks,the au-thors address the distribution shift problem by implicit policy constraints with energy‐based models(EBMs)rather than explicitly modelling the behaviour policy.The EBM is powerful for representing complex multi‐modal distributions as well as the ability to distinguish in‐distribution samples and OODs.Experimental results show that their method significantly outperforms the explicit policy constraint method and other base-lines.In addition,the learnt energy model can be used to indicate OOD visits and alert the possible failure.
基金supported by the National Key Research and Development Program of China (Grant No.2022YFA 1602500)the National Natural Science Foundation of China (Grant Nos.11934004 and 12241410).
文摘The semiclassical non-perturbative atomic orbital close-coupling approach has been employed to study the electron capture and excitation processes in He^(2+)-H(1s)and He^(2+)-H(2s)collision systems.In order to ensure the accuracy of our calculated cross sections,a large number of high excited states and pseudostates are included in the expansion basis sets which are centered on the target and projectile,respectively.The total and partial charge transfer and excitation cross sections are obtained for a wide-energy domain ranging from 1 keV/amu to 200 keV/amu.The present calculations are also compared with the results from other theoretical methods.These cross section data are useful for the investigation of astrophysics and laboratory plasma.
基金Supported by the China Postdoctoral Science Foundation(4139ZRL)the National Natural Science Foundation of China(U19A2083).
文摘Background Compared with traditional biomagnetic field detection devices,such as superconducting quantum interference devices(SQUIDs)and atomic magnetometers,only giant magneto impedance(GMI)sensors can be applied for unshielded human brain biomagnetic detection,and they have the potential for application in next-generation wearable equipment for brain-computer interfaces(BCIs).Achieving a better GMI sensor without magnetic shielding requires the stimulation of the GMI effect to be maximized and environmental noise interference to be minimized.Moreover,the GMI effect stimulated in an amorphous filament is closely related to its working point,which is sensitive to both the external magnetic field and the drive current of the filament.Methods In this paper,we propose a new noise reducing GMI gradiometer with a dual-loop self-adapting structure.Noise reduction is realized by a direction-flexible differential probe,and the dual-loop structure optimizes and stabilizes the working point by automatically controlling the external magnetic field and drive current.This dual-loop structure is fully program controlled by a micro control unit(MCU),which not only simplifies the traditional constant parameter sensor circuit,saving the time required to adjust the circuit component parameters,but also improves the sensor performance and environmental adaptation.Results In the performance test,within 2 min of self-adaptation,our sensor showed a better sensitivity and signal-to-noise ratio(SNR)than those of the traditional designs and achieved a background noise of 12 pT/√Hz at 10 Hz and 7pT/√Hz at 200 Hz.Conclusion To the best of our knowledge,our sensor is the first to realize self-adaptation of both the external magnetic field and the drive current.
基金the National Natural Science Youth Foundation of China, No. 30100054,30570609 the Grants from the National Science Fund for Dis-tinguished Young Scholars, No.60225015
文摘BACKGROUND ： Many experimental results have been found in previous studies on whether laterality of brain cingulate gyrus exists in processing Chinese words information. OBJECTIVE ： To observe the function of right anterior cingulate gyrus and activation showed by MRI in processing Chinese words in a visual working memory judgment tasks, and evaluate the laterality of activated brain regions. DESIGN ： Observation experiment SETTING ： The Medical Psychological Research Center, Second Xiangya Hospital of Central South University.PARTICIPANTS： Thirteen healthy volunteers （7 males and 6 females）, aged （29±7）years ranging from 23 to 36 years old, participated in this fMRI study dunng August 2003 to Febuary 2004. They gave informed consent in accordance with guidelines set by Second Xiangya Hospital of Central South University. All subjects were native Chinese speakers and strongly right handed. METHODS ： In this study, Chinese numeral words were used as test materials and test mode of Sternberg was used in cognitive task, it was aimed to investigate the encephalic region involved in the storage and processing of Chinese numerical information. ①The head of subject was fixed with dense foam pad. Visual working task was performed according to the requests. Verbal working task was that the subject saw target items for four numerals written in Chinese, presenting for 1.5 s and then, after a short time by blank for 3.0 s. The subject saw one numeral presenting for 1.5 s and had to press one button if it was one of the shown numbers and another button if it did not belong to the presented numbers. There were two visual working memory stimuli in each stimulation block. The experiment was conducted in a single run, which consisted of seven blocks of visual working memory tasks. Different Chinese numerals were displayed in each block to avoid any practice effect （The response rate of the whole working memory task was 50%）. ②The activation of brain was scanned with a 1.5T MRI scanner （GE Signa Twinspeed） （slice thickness 5 mm, slice gap 1.5 mm, slice parallel to line between pars geniculate and splenium in corpus callosum from corona capitis to superior part of cerebellum, totally 16 to 18 layers）. ③The obtained images were pre-processed and statistically analysed with SPM 99 software. The procedure included timeslice adjusted, realigned, nomalized and smoothed, According to experimental task, data from each subject were analysed to obtain t value of each voxel. Brain activation image was got by Student＇s t test and statistic was presented by pseudo-color. Statistical parameter image was formed by overlapping brain activation image on three-dimensional structure image, and the threshold value was set at P〈 0.05 with ten or more continous voxels （T ≥ 4.64, K ≥ 10 voxels）. The brain activation images of all the subjects were calculated and overlapped into mean brain activation images. The regions with different activation density were found out. The activation voxels in regions-of-interest were checked to calculate a laterality index for each condition. The negative value indicated right hemisphere dominance. MAIN OUTCOME MEASURES ： fMRI activation and laterality coefficient of Chinese numedal working task.RESULTS： Thirteen healthy subjects participated in the result analysis. ①fMRI activation of Chinese numerial working task： The results showed that the working memory task with Chinese words not only activated left cerebral cortex including left superior frontal gyrus （BA6/10）, left middle frontal gyrus （BA9）, left inferior frontal gyrus （BA45/9/47）, but also activated right cerebral cortex including right middle frontal gyrus （BA10/46/8）, right inferior frontal lobe （BA47）. Specially, peak activation was located in right anterior cingulate gyrus （BA32） with an activation volume of 879 （voxels）. It indicated that superior, middle and inferior frontal gyrus, bilateral Broca regions and anterior cingutate involved in the working memory of Chinese words. ②Asymmertry index ： The asymmetry index was -0.47 for frontal lobe, ＋0.42 for temporal lobe, ＋0.14 for parietal lobe and -1.00 for occipital lobe. It indicated that the right frontal lobe, left temporal lobe, left parietal lobe and dght occipital lobe were more involved in the Chinese numedal working task.
基金financially supported by the National Natural Science Foundation of China(81971632,51773231)the Natural Science Foundation of Guangdong Province(2020A1515010425,2022A1515010024)+1 种基金Key Scientific and Technological Program of Guangzhou City(201802020023)Shenzhen Science and Technology Project(JCYJ20190807160801664,JCYJ20220818103207016).
文摘Image-guided thermal ablation(TA),which is less invasive,has been widely applied for treating various kinds of tumors.However,TA still poses the potential risk of thermal damage to sensitive tissue nearby.Therefore,an adjunctive thermoprotective hydrodissection technique with constant injection of 5%glucose(5%Glu)has currently been adopted for clinical application,but this may be hazardous to humans.In this study,a multifunctional hyaluronic acid-based hydrogel(HA-Dc)was developed for hydrodissection.Compared with 5%Glu(the most clinically used solution)and the previously reported F127 hydrogel,the HA-Dc hydrogel was studied in vitro in a porcine liver model and in vivo in a rabbit model and showed good injectability and better tissue retention,stability,and thermoprotective properties throughout the TA procedure.Furthermore,in the preclinical evaluation in a Macaca fascicularis(M.fascicularis)model,HA-Dc showed excellent performance in terms of stricter neuroprotection compared with 5%Glu.In addition,the HA-Dc hydrogel with good biocompatibility and controllable degradation behavior in vivo could be a promising platform for thermal protection during clinical TA procedures.
基金the National Natural Science Foundation of China(No.51773231)Shenzhen Science and Technology Project(No.JCYJ20190807160801664)the Foundation of Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument(No.2020B1212060077).
文摘Nanomaterial-mediated phototherapy in tumor treatment has been developed rapidly in the past few years due to its noninvasive character.However,the low energy conversion efficiency and high recombination rate of the photo-triggered electron–hole pairs of single nano-agent limit the phototherapy efficiency.Herein,we constructed a novel two-dimensional nanoheterojunction MoS_(2)-Ti_(3)C_(2)(MT),which allowed a high photothermal conversion efficiency(59.1%)as well as an effective separation of photo-triggered electron–hole pairs for reactive oxygen species(ROS)generation under single 808 nm laser irradiation.Upon the modification of the mitochondrial targeted molecule(3-proxycarboxylic)triphenyl phosphine bromide(TPP)and 4T1 cell membrane,m@MoS_(2)-Ti_(3)C_(2)/TPP(m@MTT)could effectively target to the tumor cell and further locate to the mitochondria to amplify tumor-specific oxidative stress,which not merely effectively inhibits the local tumor growth but also induces tumor immunogenic cell death(ICD)for activating antitumor immune response.Additionally,cytosine guanine dinucleotide(CPG),as a Toll-like receptor 9(TLR9)agonist,was further introduced to the system to boost adaptive immune responses,resulting in improved level of cytotoxic T cells as well as a decrease in the number of regulatory T cells.In vivo antitumor mechanism studies demonstrated that not only the primary and distant tumors in 4T1 bearing-tumor mice model were significantly inhibited,but also the lung metastasis of tumor was effectively suppressed.Therefore,this work revealed the ROS generation mechanism of MT nanoheterojunction and provided a novel strategy to fabricate a biomedically applicable MT nanoheterojunction for tumor treatment.
基金supported in part by National Science Foundation of China(No.51707117)。
文摘The single-line-to-ground faults with line breaks(SLGFs-LBs)occur more and more frequently in distribution networks and can cause major safety accidents.It is difficult to distinguish the single-line-to-ground faults(SLGFs)in resonant grounding systems and ungrounding systems due to the same electrical characteristics on the source side and uncertain operation conditions of distribution networks.This paper proposes a method for distinguishing SLGFs-LBs and SLGFs.First,the source-side and load-side voltage characteristics of SLGFs and SLGFs-LBs are analyzed,and the phase difference between the voltages of the fault phase and non-fault phase on the load side is selected as the identification criterion.Phasor measurement units(PMUs)are selected as measuring devices.Then,the effects of operation conditions and external devices in distribution networks on the proposed method are discussed,and the phase errors caused by them are calculated to correct the identification method.Finally,the field testing and simulation experiments are conducted to verify the effectiveness and robustness of the proposed method.
基金supported by the National Key R&D Program of China(2020YFA0709900,2021YFB3200302)the National Natural Science Foundation of China(62288102,22075139,22077101)Fundamental Research Funds for the Central Universities.
文摘Wearable sweat sensors are becoming increasingly popular for their robust capabilities in non-invasive,dynamic,and continuous real-time monitoring of biological information.Real-time monitoring of large-scale samples is crucial for realizing intelligent health.A major bottleneck for enabling large-scale sweat elucidation is the fabrication of wearable sensors equipped with microfluidic devices and flexible electrodes in a cost-effective,homogeneous performance and rapid large-scale way.Herein,a“Screen+Wax”-printing technique was introduced to prepare these components and construct“Lego Bricks”type wearable sweat sensor sensor to monitor sweat Na^(+)and K^(+).Flexible electrode arrays and paper-based microfluidic layers(they act as building blocks)were fabricated on polyethylene terephthalate and paper surfaces,respectively,using screen printing and wax printing.Gold nanoparticles and Na^(+)/K^(+)ion-selective membranes were modified on the electrode surfaces by electrodeposition and drop coating,respectively.In this work,we highlight the excellent performance of the“Lego Bricks”type wearable sweat sensor in testing the Na^(+)and K^(+)imbalance of sweat from different body regions during exercise and,more significantly,to track the physical activity during prolonged exercise under different interventions.Furthermore,the prepared“Lego Bricks”wearable sweat ion electrochemical sensor is demonstrated to be capable of large-scale samples elucidation with outstanding performance and costeffectiveness,which is expected to deeply integrate sweat monitoring into physical activity,providing an important tool for intelligent health.
文摘Weather-related failures significantly challenge the reliability of distribution systems. To enhance the risk management of weather-related failures, an interpretable extra-trees based weather-related risk prediction model is proposed in this study. In the proposed model, the interpretability is successfully introduced to extra-trees by analyzing and processing the paths of decision trees in extra-trees. As a result, the interpretability of the proposed model is reflected in the following three respects: it can output the importance, contribution, and threshold of weather variables at high risk. The importance of weather variables can help in developing a long-term risk prevention plan. The contribution of weather variables provides targeted operation and maintenance advice for the next prediction period. The threshold of weather variables at high risk is critical in further preventing high risks. Compared with the black-box machine learning risk prediction models, the proposed model overcomes the application limitations. In addition to generating predicted risk levels, it can also provide more guidance information for the risk management of weather-related failures.
基金The work in this paperwas supported by the National Natural Science Foundation for Young Scientists of China(31801804)the Guangxi Innovation-Driven Development Special Fund Project(GuikeAA18242011)+1 种基金the Key Research and Development Program of Nanning(20192065)the Fund Project of the Key Laboratory of Integrated Pest Management on Crops in South China,Ministry of Agriculture and Rural Area,P.R.China(SCIPM2018-05).
文摘Computer vision is a field that involves making a machine “see”.This technology uses a camera and computer instead of the human eye to identify,track and measure targets for further image processing.With the development of computer vision,such technology has been widely used in the field of agricultural automation and plays a key role in its development.This review systematically summarizes and analyzes the technologies and challenges over the past three years and explores future opportunities and prospects to form the latest reference for researchers.Through the analyses,it is found that the existing technology can help the development of agricultural automation for small field farming to achieve the advantages of low cost,high efficiency and high precision.However,there are still major challenges.First,the technology will continue to expand into new application areas in the future,and there will be more technological issues that need to be overcome.It is essential to build large-scale data sets.Second,with the rapid development of agricultural automation,the demand for professionals will continue to grow.Finally,the robust performance of related technologies in various complex environments will also face challenges.Through analysis and discussion,we believe that in the future,computer vision technology will be combined with intelligent technology such as deep learning technology,be applied to every aspect of agricultural production management based on large-scale datasets,be more widely used to solve the current agricultural problems,and better improve the economic,general and robust performance of agricultural automation systems,thus promoting the development of agricultural automation equipment and systems in a more intelligent direction.
基金This work was supported by the Shuguang Program from Shanghai Education Development Foundation and Shanghai Municipal Education Commission(18SG035)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University(KF2015).Dr.Q.Zhang thanks the support by the National Natural Science Foundation of China(52072323,51872098).
文摘Owing to excellent conductivity and abundant surface terminals,MXene-based heterostructures have been intensively investigated as energy storage materials.However,elaborate design of the structure and composition of MXene-based hybrids towards superior electrochemical performance is still challenging.Herein,we present an ingenious leaf-inspired design for preparing a unique Sb_(2)S_(3)/nitrogen-doped Ti_(3)C_(2)T_(x)MXene(L-Sb_(2)S_(3)/Ti_(3)C_(2))hybrid.In-situ TEM observations reveal that the leaflike Sb_(2)S_(3)nanoparticles with numerous mesopores can well relieve the large volume changes via an inward pore filling mechanism with only 20%outward expansion,whereas highly conductive N-doped Ti_(3)C_(2)T_(x)nanosheets can serve as the robust mechanical support to reinforce the structural integrity of the hybrid.Benefiting from the structural and constituent merits,the L-Sb_(2)S_(3)/Ti_(3)C_(2)anode fabricated exhibits a fast sodium storage behavior in terms of outstanding rate capability(339.5 mA h g^(-1)at 2,000 mA g^(-1))and high reversible capacity at high current density(358.2 mA h g^(-1)at 1,000 mA g^(-1)after 100 cycles).Electrochemical kinetic tests and theoretical simulation further manifest that the boosted electrochemical performance mainly arises from such a unique leaf-like Sb_(2)S_(3)mesoporous nanostructure with abundant active sites,and enhanced Na^(+)adsorption energy on the heterojunction formed between Sb_(2)S_(3)nanoparticles and Ti_(3)C_2)matrix.
基金This research was conducted in the College of Mechanical and Electronic Engineering,Northwest A&F University,and was supported by research grants from the General Program of the National Natural Science Foundation of China(61175099).
文摘The harvesting of fresh kiwifruit is a labor-intensive operation that accounts for more than 25%of annual production costs.Mechanized harvesting technologies are thus being developed to reduce labor requirements for harvesting kiwifruit.To improve the efficiency of a harvesting robot for picking kiwifruit,we designed an end-effector,which we report herein along with the results of tests to verify its operation.By using the established method of automated picking discussed in the literature and which is based on the characteristics of kiwifruit,we propose an automated method to pick kiwifruit that consists of separating the fruit from its stem on the tree.This method is experimentally verified by using it to pick clustered kiwifruit in a scaffolding canopy cultivation.In the experiment,the end-effector approaches a fruit from below and then envelops and grabs it with two bionic fingers.The fingers are then bent to separate the fruit from its stem.The grabbing,picking,and unloading processes are integrated,with automated picking and unloading performed using a connecting rod linkage following a trajectory model.The trajectory was analyzed and validated by using a simulation implemented in the software Automatic Dynamic Analysis of Mechanical Systems(ADAMS).In addition,a prototype of an end-effector was constructed,and its bionic fingers were equipped with fiber sensors to detect the best position for grabbing the kiwifruit and pressure sensors to ensure that the damage threshold was respected while picking.Tolerances for size and shape were incorporated by following a trajectory groove from grabbing and picking to unloading.The end-effector separates clustered kiwifruit and automatically grabs individual fruits.It takes on average 4–5 s to pick a single fruit,with a successful picking rate of 94.2%in an orchard test featuring 240 samples.This study shows the grabbing–picking–unloading robotic end-effector has significant potential to facilitate the harvesting of kiwifruit.
基金supported by the Shuguang Program from Shanghai Education Development Foundation and Shanghai Municipal Education Commission(18SG035)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University(KF2015)。
文摘The exploration of advanced MoS_(2)-based electrode materials overcoming their inherent low conductivity and large volume changes is of importance for next-generation energy storage.In this work,we report a simple and high-efficient one-pot hydrothermal approach to prepare a unique and stable 1D/2D heterostructure.In the architecture,ultrathin carbon layer-coated MoS_(2) nanosheets with large expanded interlayer of 1.02 nm are vertically grown onto the Ti_(3)C_(2) MXene and cross-linked carbon nanotubes(CNTs),giving rise to a highly conductive 3D network.The interlayer expanded MoS_(2) nanosheets can greatly facilitate the Na ions/electrons transmission.Meanwhile,the N-doped 1D/2D CNTs-Ti_(3)C_(2) matrix can be used as a strong mechanical support to well relieve the large volume expansion upon cycles.As a combination result of several advantages,the developed quaternary C-MoS_(2)/CNTs-Ti_(3)C_(2) composite anode shows an excellent sodium storage performance(562 mA h g^(-1) at 100 mA g^(-1) after 200 cycles)and rate capability(475 mA h g^(-1) at 2000 mA g^(-1)).The density functional theory calculations further prove that the full combination of layer-expanded MoS_(2) nanosheets and N-doped Ti_(3)C_(2) matrix can significantly enhance the adsorption energy of Na ions,further resulting in the enhancement of sodium storage capabilities.
基金financially supported by the Shuguang Program from Shanghai Education Development Foundation and Shanghai Municipal Education Commission (18SG035)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University (KF2015)。
文摘Layered structure MoS_(2) nanosheets have shown great potential for energy storage applications.However,the methodology for elaborately controllable growth of MoS_(2) onto carbonaceous matrix for promoting the electrochemical performance is highly desirable.Herein,a high-effective,all-in-one in-situ conversion growth strategy has been proposed to construct a stable sandwich-type nanostructure.The formation of the optimized C-MoS_(2)/NCNTs product undergoes a dissolution-recrystallization process,in which ultra-thin carbon layer-coated MoS_(2) nanosheets densely assembled onto the surface of polyimide(PI)derived N-doped carbon nanotubes(CNTs).Theoretical simulation reveals that MoS_(2) nanosheets possessing an expanded interlayer spacing of 0.92 nm can greatly reduce the barrier energy of Na ions mitigation.Ac-cordingly,the as-made C-MoS_(2)/NCNTs anode delivers superior cycling stability(82%capacity retention after 400 cycles at 1 A g^(−1))and rate performance(348 mAh g^(−1) at 2 A g^(−1)).The results demonstrate that the expanded MoS_(2) interlayer distance,ultrathin outer carbon coating,and N-doped CNTs matrix together accounts for the outstanding sodium storage capability for the C-MoS_(2)/NCNTs electrode.
基金sponsored by the National Key Research and Development Program of China‘Modes and key supporting technologies for the sustainable development of smart grid based on TCP ISGAN of the International Energy Agency’(2019YFE0102900).
文摘Intelligent perception is the cornerstone of digitalisation of power grid.Due to the closest connection with users,the information perception ability of distribution network directly affects the reliability of power supply.Distribution network has a wide range of geographical distribution and equipment types.The application of intelligent perception is with high complexity and dynamics under the limitation of both technology and management.Therefore,the study first sorts out the current application status of intel-ligent perception technology and equipment in distribution network from three appli-cation fields including distribution automation,metering systems,and inspection.Then,the constraints of existing intelligent perception applications and the key points of further research are pointed out.Finally,the development trends of intelligent perception technology in distribution network are presented from the three aspects of basic tech-nology,perception equipment,and advanced applications.With the improvement of sensing,communication,energy acquisition,chips and perception equipments,the depth and breadth of advanced applications in distribution network will be expanded.The research results can provide references for the follow‐up research and practice of intel-ligent perception in distribution networks.
基金supported by the National Natural Science Foundation of China(51773231)the Natural Science Foundation of Guangdong Province(2016A030313315)+1 种基金Shenzhen Science and Technology Project(JCYJ20190807160801664)the Project of Key Laboratory of Sensing Technology and Biomedical Instruments of Guangdong Province(2011A060901013)。
文摘Although sonodynamic therapy(SDT)is a promising non-invasive tumor treatment strategy due to its safety,tissue penetration depth and low cost,the hypoxic tumor microenvironment limits its therapeutic effects.Herein,we have designed and developed an oxygen-independent,ROS-amplifying chemo-sonodynamic antitumor therapy based on novel pH/GSH/ROS triple-responsive PEG-PPMDT nanoparticles.The formulated artemether(ART)/Fe_(3)O_(4)-loaded PEG-PPMDT NPs can rapidly release drug under the synergistic effect of acidic endoplasmic pH and high intracellular GSH/ROS levels to inhibit cancer cell growth.Besides,the ROS level in the NPs-treated tumor cells is magnified by ART via interactions with both Fe^(2+)ions formed in situ at acidic pH and external ultrasound irradiation,which is not affected by hypoxia tumor microenvironment.Consequently,the enriched intracellular ROS level can cause direct necrosis of ROS-stressed tumor cells and further accelerate the drug release from the ROS-responsive PEG-PPMDT NPs,achieving an incredible antitumor potency.Specifically,upon the chemo-sonodynamic therapy by ART/Fe_(3)O_(4)-loaded PEG-PPMDT NPs,all xenotransplants of human hepatocellular carcinoma(HepG2)in nude mice shrank significantly,and 40% of the tumors were completely eliminated.Importantly,the Fe3O4 encapsulated in the NPs is an efficient MRI contrast agent and can be used to guide the therapeutic procedures.Further,biosafety analyses show that the PEG-PPMDT NPs possess minimal toxicity to main organs.Thus,our combined chemo-sonodynamic therapeutic method is promising for potent antitumor treatment by controlled release of drug and facile exogenous generation of abundant ROS at target tumor sites.
基金supported by National Natural Science Foundation of China (No.51307109)State Grid Corporation of China (No.XT71-16-001)
文摘With the proposed concept of global energy interconnection, half-wavelength alternating current transmission(HWACT) technology becomes of more interest.HWACT lines can be adopted to establish a pointto-grid system, in which the penetrating power(PP) is produced between receiving terminals, having a significant effect on the power flow distribution.In order to investigate this phenomenon, the PP characteristics of the HWACT system are researched in this paper.First, the mathematical relationship between the transmission power and terminal bus voltages of a single HWACT line is derived using the equations of a distributed parameter model.The research indicates that the relationship between power and terminal voltages shows ‘‘reverse characteristics"opposite to those of regular short transmission lines.Then, the concept and definition of PP in a point-to-grid system with two receiving terminals are proposed, and the corresponding relationship between PP and the terminal bus voltages is derived.Simulations are carried out to validate the theory under different conditions, so that the accuracy and adaptiveness of the theoretical analysis can be proved.In addition, the results demonstrate that selecting the location for a HWACT system has demanding requirements in order to control the value of PP.
基金This research was supported by the National Natural Science Foundation of China(Grant No.51779143)the Cultivation of Scientific Research Ability of Young Talents of Shanghai jiao Tong University(Grant No.19×100040072).
文摘Slurry pipeline transport is widely used in several industrial processes.Calculating the specific power consumption(SPC)and determining the best working conditions are important for the design and operation of transportation systems.Based on the Shanghai Jiao Tong University high-concentration multi-sized slurry pressure drop(SJTU-HMSPD)pipeline-resistance-calculation model,the SJTU-SPC model for calculating the power required to transport a unit volume of solid materials over a unit pipeline length is established for a slurry transport system.The said system demonstrates a uniformity coefficient in the 1.26–7.98 range,median particle size of 0.075–4 mm,particle volume concentration of 10–60%,and pipeline diameter of 0.203–0.8 m.The results obtained were successfully verified against existing experimental data.The influence of parameters,such as particle-gradation uniformity coefficient,median particle size,pipe diameter,and particle volume concentration,on the SPC were analysed.The results revealed that the greater is the uniformity coefficient,the smaller is the minimum specific energy consumption and the larger the optimal transport concentration for a constant,median particle size slurry.As observed,the optimal transport concentration for broad-graded sand equalled approximately 48%.These results supplement the conclusions of existing research,indicating that the optimal transport concentration is approximately 30%and provides theoretical support for high concentration transportation of broad graded slurry.
