Sperm is essential for successful artificial insemination in dairy cattle,and its quality can be influenced by both epi-genetic modification and epigenetic inheritance.The bovine germline differentiation is characteri...Sperm is essential for successful artificial insemination in dairy cattle,and its quality can be influenced by both epi-genetic modification and epigenetic inheritance.The bovine germline differentiation is characterized by epigenetic reprogramming,while intergenerational and transgenerational epigenetic inheritance can influence the offspring’s development through the transmission of epigenetic features to the offspring via the germline.Therefore,the selec-tion of bulls with superior sperm quality for the production and fertility traits requires a better understanding of the epigenetic mechanism and more accurate identifications of epigenetic biomarkers.We have comprehensively reviewed the current progress in the studies of bovine sperm epigenome in terms of both resources and biological discovery in order to provide perspectives on how to harness this valuable information for genetic improvement in the cattle breeding industry.展开更多
Permanent magnet synchronous motor(PMSM)speed control systems with conventional linear active disturbance rejection control(CLADRC)strategy encounter issues regarding the coupling between dynamic response and disturba...Permanent magnet synchronous motor(PMSM)speed control systems with conventional linear active disturbance rejection control(CLADRC)strategy encounter issues regarding the coupling between dynamic response and disturbance suppression and have poor performance in suppressing complex nonlinear disturbances.In order to address these issues,this paper proposes an improved two-degree-of-freedom LADRC(TDOF-LADRC)strategy,which can enhance the disturbance rejection performance of the system while decoupling entirely the system's dynamic and anti-disturbance performance to boost the system robustness and simplify controller parameter tuning.PMSM models that consider total disturbances are developed to design the TDOF-LADRC speed controller accurately.Moreover,to evaluate the control performance of the TDOF-LADRC strategy,its stability is proven,and the influence of each controller parameter on the system control performance is analyzed.Based on it,a comparison is made between the disturbance observation ability and anti-disturbance performance of TDOF-LADRC and CLADRC to prove the superiority of TDOF-LADRC in rejecting disturbances.Finally,experiments are performed on a 750 W PMSM experimental platform,and the results demonstrate that the proposed TDOF-LADRC exhibits the properties of two degrees of freedom and improves the disturbance rejection performance of the PMSM system.展开更多
Pharmaceutical production is changing from batch production to continuous production,during which granulation is one of the most important unit operations.The quality of mass-produced products is traditionally guarant...Pharmaceutical production is changing from batch production to continuous production,during which granulation is one of the most important unit operations.The quality of mass-produced products is traditionally guaranteed by conducting off-line testing,which cannot meet the demand of continuous production for real-time monitoring of critical process parameters and critical quality attributes(CQAs)of the pharmaceutical granulation technology.Since the U.S.Food and Drug Administration proposed process analytical technology(PAT)in 2004,many PAT tools have been developed to monitor the granulation process and provide information regarding the granulation operation conditions and endpoint determination.In this article,we review the recent research and application of two PAT modes in the granulation process,namely,single CQA and multi-CQA PAT,with the aim to provide references for comprehensively improving the technological level of the pharmaceutical granulation process.Furthermore,the potential applications in traditional Chinese Medicine are discussed.展开更多
The migration of protons during the oxygen evolution reaction(OER)is a key factor that affects the performance of OER catalysts.To enhance proton transportation,we designed a catalyst based on nickel/iron-pyromellitic...The migration of protons during the oxygen evolution reaction(OER)is a key factor that affects the performance of OER catalysts.To enhance proton transportation,we designed a catalyst based on nickel/iron-pyromellitic acid(NiFe-PMA)prepared by the electrochemical deposition method.This catalyst exhibited a low overpotential of 188 mV at a current density of 10 mA·cm^(-2),a Tafel slope of 28.2 mV·dec^(-1),and long-term stability for 30 days with a current of 50 mA·cm^(-2).We characterized the NiFe-PMA catalyst using various techniques,including Fourier transform infrared(FTIR)spectroscopy,Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),X-ray absorption spectroscopy(XAS),transmission electron microscopy(TEM),scanning electron microscopy(SEM),and inductively coupled plasma-optical emission spectrometry(ICP-OES).Our results showed that NiFe-PMA contains nickel,iron atoms,and both coordinated and uncoordinated carboxylate groups.Additionally,XPS data confirmed that carboxylate ligands could adjust the outer electronic structure of metal ions,resulting in the high valence state of Ni in NiFe-PMA.The result of XAS indicated that the nickel atoms present in the catalyst might be easier to maintain a higher chemical state.Further investigations using kinetic isotope effects(KIEs)and proton inventory revealed that the uncoordinated carboxylic protons played a crucial role in receiving protons during the OER,which promoted the proton transfer of the rate-determining step of the OER.Our novel electrocatalysts provide a new strategy for designing more active and cost-effective catalysts for the OER.展开更多
Large,3D curved electronics are a trend of the microelectronic industry due to their unique ability to conformally coexist with complex surfaces while retaining the electronic functions of 2D planar integrated circuit...Large,3D curved electronics are a trend of the microelectronic industry due to their unique ability to conformally coexist with complex surfaces while retaining the electronic functions of 2D planar integrated circuit technologies.However,these curved electronics present great challenges to the fabrication processes.Here,we propose a reconfigurable,mask-free,conformal fabrication strategy with a robot-like system,called robotized‘transfer-and-jet’printing,to assemble diverse electronic devices on complex surfaces.This novel method is a ground-breaking advance with the unique capability to integrate rigid chips,flexible electronics,and conformal circuits on complex surfaces.Critically,each process,including transfer printing,inkjet printing,and plasma treating,are mask-free,digitalized,and programmable.The robotization techniques,including measurement,surface reconstruction and localization,and path programming,break through the fundamental constraints of 2D planar microfabrication in the context of geometric shape and size.The transfer printing begins with the laser lift-off of rigid chips or flexible electronics from donor substrates,which are then transferred onto a curved surface via a dexterous robotic palm.Then the robotic electrohydrodynamic printing directly writes submicrometer structures on the curved surface.Their permutation and combination allow versatile conformal microfabrication.Finally,robotized hybrid printing is utilized to successfully fabricate a conformal heater and antenna on a spherical surface and a flexible smart sensing skin on a winged model,where the curved circuit,flexible capacitive and piezoelectric sensor arrays,and rigid digital–analog conversion chips are assembled.Robotized hybrid printing is an innovative printing technology,enabling additive,noncontact and digital microfabrication for 3D curved electronics.展开更多
Sixty sediment samples were collected from the main Songhua River in three years. Twelve polybrominated diphenyl ether( PBDE) congeners( BDE17,28,47,66,99,100,153,154,138,183,and BDE-209) were detected to state the po...Sixty sediment samples were collected from the main Songhua River in three years. Twelve polybrominated diphenyl ether( PBDE) congeners( BDE17,28,47,66,99,100,153,154,138,183,and BDE-209) were detected to state the pollution situation. The results showed that the total concentration of total PBDEs ranges from 0. 424 to 23. 0 ng / g dry weight,with the mean of 3. 02 ng / g,and the total PBDEs concentration is at relative low level compared with those worldwide. The congener profile showed that BDE-209 is the dominant congener that accounts for more than 80. 1% of total PBDEs in sediments,followed by BDE-47 and BDE-99. These profiles are consistent with a high consumption of Deca-BDEs for the brominated flame retardant market in China. The results of spatial and seasonal observations indicated that local sources,temperature variation, and hydrologic conditions are significant factors on PBDEs concentrations. Hazard quotients suggested that PBDEs pose no potential risk to benthic organisms in detected area at present.展开更多
The key objective of this paper is to improve the approximation of a sufficiently smooth nonperiodic function defined on a compact interval by proposing alternative forms of Fourier series expansions. Unlike in classi...The key objective of this paper is to improve the approximation of a sufficiently smooth nonperiodic function defined on a compact interval by proposing alternative forms of Fourier series expansions. Unlike in classical Fourier series, the expansion coefficients herein are explicitly dependent not only on the function itself, but also on its derivatives at the ends of the interval. Each of these series expansions can be made to converge faster at a desired polynomial rate. These results have useful implications to Fourier or harmonic analysis, solutions to differential equations and boundary value problems, data compression, and so on.展开更多
The rational modulation of electronic structure is highly desirable to develop an efficient alkaline hydrogen evolution reaction(HER)catalyst for renewable energy applications.Metal hydroxide such as Ni(OH)_(2) has be...The rational modulation of electronic structure is highly desirable to develop an efficient alkaline hydrogen evolution reaction(HER)catalyst for renewable energy applications.Metal hydroxide such as Ni(OH)_(2) has been proven useful for promoting alkaline HER,but the performance remains unsatisfactory.Herein,the electronic structure of Ni(OH)_(2) is modulated by the interfacial electron rearrangement between Ni-Ni(OH)_(2) heterojunction.Combined experiments with DFT simulations,the electrons of Ni species accumulate to the interfacial Ni-Ni(OH)_(2) sites,which modifies the d band center for promoting conversion of hydrogen intermediates and narrows the energy gap for boosting charge transfer in the HER process.Thus,the integrated electrode exhibits an efficient HER performance to drive10 mA cm^(-2) at the overpotential of 72 mV with a low Tafel slope of 43 mV dec^(-1).Our work renders a valuable insight for understanding and rationally designing efficient catalysts in alkaline HER.展开更多
Ultrasound-magnetic field coaxial hybrid Gas Tungsten Arc Welding(U-M-GTAW)is proposed as a means to control arc characteristics.The arc characteristics and the mechanism to change them,in an ultrasound-magnetic field...Ultrasound-magnetic field coaxial hybrid Gas Tungsten Arc Welding(U-M-GTAW)is proposed as a means to control arc characteristics.The arc characteristics and the mechanism to change them,in an ultrasound-magnetic field coaxial hybrid GTAW,were studied by both experimental and theoretical analyses.The results showed that a periodic rotation and compression of the arc shape were obtained in U-M-GTAW and the arc energy was also enhanced.The most obvious compression of the arc shape in U-M-GTAW was obtained,compared with GTAW,M-GTAW and U-GTAW.At the same time,a periodic rotation of the arc was observed in U-M-GTAW.The geometric parameters of the arc shape in U-M-GTAW are reduced more than double compared with traditional GTAW.The arc voltage in the hybrid GTAW was increased,especially in the U-M-GTAW.The electromagnetic force and acoustic radiation force were the main factors for the change of arc characteristics in the U-M-GTAW.展开更多
Sea surface temperature (SST) is closely related to global climatechange, ocean ecosystem, and ocean disaster. Accurate prediction of SST isan urgent and challenging task. With a vast amount of ocean monitoring dataar...Sea surface temperature (SST) is closely related to global climatechange, ocean ecosystem, and ocean disaster. Accurate prediction of SST isan urgent and challenging task. With a vast amount of ocean monitoring dataare continually collected, data-driven methods for SST time-series predictionshow promising results. However, they are limited by neglecting complexinteractions between SST and other ocean environmental factors, such as airtemperature and wind speed. This paper uses multi-factor time series SSTdata to propose a sequence-to-sequence network with two-module attention(TMA-Seq2seq) for long-term time series SST prediction. Specifically, TMASeq2seq is an LSTM-based encoder-decoder architecture facilitated by factorand temporal-attention modules and the input of multi-factor time series. Ittakes six-factor time series as the input, namely air temperature, air pressure,wind speed, wind direction, SST, and SST anomaly (SSTA). A factor attentionmodule is first designed to adaptively learn the effect of different factors onSST, followed by an encoder to extract factor-attention weighted features asfeature representations. And then, a temporal attention module is designedto adaptively select the hidden states of the encoder across all time steps tolearn more robust temporal relationships. The decoder follows the temporalattention module to decode the feature vector concatenated from the weightedfeatures and original input feature. Finally, we use a fully-connect layer tomap the feature into prediction results. With the two attention modules, ourmodel effectively improves the prediction accuracy of SST since it can notonly extract relevant factor features but also boost the long-term dependency.Extensive experiments on the datasets of China Coastal Sites (CCS) demonstrate that our proposed model outperforms other methods, reaching 98.29%in prediction accuracy (PACC) and 0.34 in root mean square error (RMSE).Moreover, SST prediction experiments in China’s East, South, and Yellow Seasite data show that the proposed model has strong robustness and multi-siteapplicability.展开更多
Objective:To investigate the association between gastrointestinal heat retention syndrome(GHRS)and adult chronic eczema.Methods:This caseecontrol study compared GHRS/GHRS accompanied by damp-heat syndrome(GHRSDHS)and ...Objective:To investigate the association between gastrointestinal heat retention syndrome(GHRS)and adult chronic eczema.Methods:This caseecontrol study compared GHRS/GHRS accompanied by damp-heat syndrome(GHRSDHS)and other patient characteristics between subjects with(cases)and without chronic eczema(controls)to identify potential factors associated with this condition.Semi-structured questionnaires were used to collect data via face-to-face interviews.Participants were recruited from Dongzhimen Hospital affiliated with Beijing University of Chinese Medicine.A logistic regression analysis was performed on the collected data,and odds ratios(ORs)were calculated.Results:A total of 168 cases and 172 controls were recruited.Among the cases of adult chronic eczema,there were 79 subjects with GHRS and 68 with GHRS-DHS.Sex(P=.02,OR=0.54,95%confidence interval[CI]:0.32-0.91),GHRS(P=.04,OR=1.90,95%CI:1.02-3.51),GHRS-DHS(P<.001,OR=4.89,95%CI:2.36-10.15),high sweet food consumption(P=.04,OR=2.03,95%CI:1.03-3.97),and mental stress(P=.01,OR=2.37,95%CI:1.26-4.47)were each found to be associated with chronic eczema.Furthermore,GHRS had a weak positive correlation with eczema EASI severity as measured by the eczema area and severity index(EASI)(P=003).Conclusion:GHRS/GHRS-DHS may be associated with adult chronic eczema.In the future,prospective cohort studies with larger samples should be conducted to investigate the cause and effect association between GHRS and adult chronic eczema.展开更多
Objectives: The purpose of this research is to determine the quantitative relationship between the peak wall stress of abdominal aortic aneurysm (AAA) and its clinical risk factors including its maximum diameter, asym...Objectives: The purpose of this research is to determine the quantitative relationship between the peak wall stress of abdominal aortic aneurysm (AAA) and its clinical risk factors including its maximum diameter, asymmetry index, wall thickness and abnormal high blood pressure. Methods: The response surface experimental design with one response and four variables was used to design the experimental tests. Thirty experiments were performed through finite element analysis in order to obtain the designed response values. Results: A nonlinear multivariable regression function was developed based on the experimental data. Results demonstrated the inefficiency of traditional 5-cm criterion for estimating the rupture of AAA. The profound effect of wall thickness on the peak wall stress has been observed and validated by the existing publications. Conclusion: The conventional 5-cm criterion for estimating AAA rupture might induce biased prediction, and multiple clinical risk factors need to be considered in realistic clinical settings.展开更多
Residual thermal stresses and warping of the anode-supported planar solid oxide fuel cell (SOFC) were estimated numerically. A 3D finite element (FE) model with viscoelastic constitutive equations was established to c...Residual thermal stresses and warping of the anode-supported planar solid oxide fuel cell (SOFC) were estimated numerically. A 3D finite element (FE) model with viscoelastic constitutive equations was established to calculate the residual stress and warping for the cell. In the fabrication of the cells, some mechanical restriction was employed during the high-temperature treatment followed by a cooling stage in order to prevent the button cell from warping, and then from these specific boundaries and loading conditions, a FE simulation was used to calculate the distribution of the internal stresses in the cell. The results indicate that the concentration of compressive stress appears in the electrolyte layer, and that could cause interfacial micro-cracks or even cohesive failure. Furthermore, from the numerical study, the annealing time (or continuous cooling) is related to the residual stress in the material due to creeping. The compressive stress in the electrolyte layer can be reduced significantly by increasing the cooling time. Therefore, it is possible to optimize the annealing time in order to make the SOFCs flat and have less residual stress, improving the mechanical durability.展开更多
Membrane filtration is one of the effective approaches to harvest microalgae for industrial biofuel production.However,during the filtration process,microalgae cells and extracellular organic matter(EOM)will deposit o...Membrane filtration is one of the effective approaches to harvest microalgae for industrial biofuel production.However,during the filtration process,microalgae cells and extracellular organic matter(EOM)will deposit on the membrane surface leading to reversible membrane fouling that can be removed by physical methods.When hydrophobic EOM is adsorbed on the membrane surface or inside pores,it will build up a gel layer,causing irreversible membrane fouling.Irreversible fouling can only be removed using chemical methods that will decrease membrane lifespan and increase operational costs.Here,we introduce a versatile superhydrophilic membrane with photo-Fenton self-cleaning property,which can prevent the reversible fouling and remove the irreversible fouling.Tannic acid(TA)and 3-aminopropyltriethoxysilane(APTES)were co-deposited on the polyvinylidene fluoride(PVDF)membrane via Schiff base and Michael addition reactions,andβ-FeOOH nanorods were inlaid on the membrane surface by in situ mineralization.The water contact angle of the modified membrane is reduced from 120°to 0°Under 60 min visible light,the hydroxyl radical(·OH)generated by the photo-Fenton reaction degraded the irreversible fouling that blocked membrane pores.The irreversible fouling rates of modified membrane was reduced from 39.57%to 3.26%,compared with the original membrane.Microalgae harvesting results illustrated that the membrane has a high flux recovery rate(FRR)of 98.2%,showed excellent passive antifouling and active antifouling performance.We believe this work will spark a novel platform for optimizing energy-efficient microalgae harvesting separation membrane modules.In addition,this method of anti-fouling filtration for microorganisms can be extended to the industrial production of various bioenergy sources and will have very promising practical applications.展开更多
Next-generation electronics that are fused into the human body can play a key role in future intelligent communication,smart healthcare,and human enhancement applications.As a promising energy supply component for sma...Next-generation electronics that are fused into the human body can play a key role in future intelligent communication,smart healthcare,and human enhancement applications.As a promising energy supply component for smart biointegrated electronics,environment-adaptive electrochemical energy storage(EES)devices with complementary adaptability and functions have garnered huge interest in the past decade.Owing to the advancements in autonomous chemistry,which regulate the constitutional dynamic networks in materials,EES devices have witnessed higher freedom of autonomous adaptability in terms of mechano-adaptable,biocompatibility,and stimuli-response properties for biointegrated and smart applications.In this mini-review,we summarize the recent progress in emerging environmentadaptive EES devices enabled by the constitutional dynamic network of mechanical adaptable materials,biocompatible materials,and stimuli-responsive supramolecular polymer materials.Finally,the challenges and perspectives of autonomous chemistry on the environment-adaptive EES devices are discussed.展开更多
The pulsed-spray fluid-bed granulation (PSFBG) process was investigated and optimized using definitive scree ning design, a recently proposed new class of three-level desig n of experiment method. Such a design enable...The pulsed-spray fluid-bed granulation (PSFBG) process was investigated and optimized using definitive scree ning design, a recently proposed new class of three-level desig n of experiment method. Such a design enabled quadratic models to be established that described the effect of six in put process parameters - inlet air temperature, inlet air humidity, binder spray rate, atomization pressure, pulse period, and pulse width - on the granule quality in a PSFBG process. Mathematical models of the mean particle size, relative size distribution width, production yield, and porosity were developed to quantify the relationships between the in flue ncing factors and critical quality attributes. On the basis of con strai nts on the desired granule properties, a design space for PSFBG was determined and ranges of the operating parameters were defined. An acceptable degree of prediction was confirmed by validation experiments, demonstrating the reliability and effectiveness of using definitive screening design to study the PSFBG process. This method can accelerate screening and optimization of this process within a large multidimensional design space.展开更多
Increasing plant photosynthetic capacity is a promising approach to boost yields,but it is particularly challenging in C3crops,such as soybean(Glycine max(L.)Merr.).Here,we identified GmFtsH25,encoding a member of the...Increasing plant photosynthetic capacity is a promising approach to boost yields,but it is particularly challenging in C3crops,such as soybean(Glycine max(L.)Merr.).Here,we identified GmFtsH25,encoding a member of the filamentation temperature-sensitive protein H protease family,as a major gene involved in soybean photosynthesis,using linkage mapping and a genome-wide association study.Overexpressing GmFtsH25 resulted in more grana thylakoid stacks in chloroplasts and increased photosynthetic efficiency and starch content,while knocking out GmFtsH25 produced the opposite phenotypes.GmFtsH25 interacted with photosystem I light harvesting complex 2(GmLHCa2),and this interaction may contribute to the observed enhanced photosynthesis.GmFtsH25 overexpression lines had superior yield traits,such as yield per plant,compared to the wild type and knockout lines.Additionally,we identified an elite haplotype of GmFtsH25,generated by natural mutations,which appears to have been selected during soybean domestication.Our study sheds light on the molecular mechanism by which GmFtsH25 modulates photosynthesis and provides a promising strategy for improving the yields of soybean and other crops.展开更多
基金funded by the National Key R&D Program of China(2021YFD1200903)Seed Fund(CAU),Shandong Provincial Natural Science Foundation(ZR2021MC070)+3 种基金the National Key R&D Program of China(2021YFF1000701-06)Shandong Provincial Natural Science Foundation(ZR2020MC165)the Earmarked Fund for CARS-36.X.W.is funded by the“Hundred Talents Program”project of Hebei Province(E2020100019)the research project of Zhongnongtongchuang(ZNTC)group(ZNTC2019A10 and ZNTC2021B12)in China.
文摘Sperm is essential for successful artificial insemination in dairy cattle,and its quality can be influenced by both epi-genetic modification and epigenetic inheritance.The bovine germline differentiation is characterized by epigenetic reprogramming,while intergenerational and transgenerational epigenetic inheritance can influence the offspring’s development through the transmission of epigenetic features to the offspring via the germline.Therefore,the selec-tion of bulls with superior sperm quality for the production and fertility traits requires a better understanding of the epigenetic mechanism and more accurate identifications of epigenetic biomarkers.We have comprehensively reviewed the current progress in the studies of bovine sperm epigenome in terms of both resources and biological discovery in order to provide perspectives on how to harness this valuable information for genetic improvement in the cattle breeding industry.
文摘Permanent magnet synchronous motor(PMSM)speed control systems with conventional linear active disturbance rejection control(CLADRC)strategy encounter issues regarding the coupling between dynamic response and disturbance suppression and have poor performance in suppressing complex nonlinear disturbances.In order to address these issues,this paper proposes an improved two-degree-of-freedom LADRC(TDOF-LADRC)strategy,which can enhance the disturbance rejection performance of the system while decoupling entirely the system's dynamic and anti-disturbance performance to boost the system robustness and simplify controller parameter tuning.PMSM models that consider total disturbances are developed to design the TDOF-LADRC speed controller accurately.Moreover,to evaluate the control performance of the TDOF-LADRC strategy,its stability is proven,and the influence of each controller parameter on the system control performance is analyzed.Based on it,a comparison is made between the disturbance observation ability and anti-disturbance performance of TDOF-LADRC and CLADRC to prove the superiority of TDOF-LADRC in rejecting disturbances.Finally,experiments are performed on a 750 W PMSM experimental platform,and the results demonstrate that the proposed TDOF-LADRC exhibits the properties of two degrees of freedom and improves the disturbance rejection performance of the PMSM system.
基金the National Natural Sciences Foundation of China(No.82074276)Tianjin Science and Technology project(No.20ZYJDJC00090).
文摘Pharmaceutical production is changing from batch production to continuous production,during which granulation is one of the most important unit operations.The quality of mass-produced products is traditionally guaranteed by conducting off-line testing,which cannot meet the demand of continuous production for real-time monitoring of critical process parameters and critical quality attributes(CQAs)of the pharmaceutical granulation technology.Since the U.S.Food and Drug Administration proposed process analytical technology(PAT)in 2004,many PAT tools have been developed to monitor the granulation process and provide information regarding the granulation operation conditions and endpoint determination.In this article,we review the recent research and application of two PAT modes in the granulation process,namely,single CQA and multi-CQA PAT,with the aim to provide references for comprehensively improving the technological level of the pharmaceutical granulation process.Furthermore,the potential applications in traditional Chinese Medicine are discussed.
基金supported by the National Key Research and Development Program of Ministry of Science and Technology of China(No.2021YFA1500604)ShanghaiTech University start-up funding.We would like to thank the Analytical Instrumentation Center(#SPST-AIC 10112914)at the School of Physical Science and Technology(SPST)+1 种基金ShanghaiTech University,for their generous support.We are grateful to Peihong Cheng at ShanghaiTech University for assisting with XPS measurements and Siyuan Du for assisting us in the XAS test at Shanghai Synchrotron Radiation Facility(SSRF)We appreciate the Centre for High-Resolution Electron Microscopy(CћEM),which is supported by SPST of ShanghaiTech University under contract No.EM02161943.
文摘The migration of protons during the oxygen evolution reaction(OER)is a key factor that affects the performance of OER catalysts.To enhance proton transportation,we designed a catalyst based on nickel/iron-pyromellitic acid(NiFe-PMA)prepared by the electrochemical deposition method.This catalyst exhibited a low overpotential of 188 mV at a current density of 10 mA·cm^(-2),a Tafel slope of 28.2 mV·dec^(-1),and long-term stability for 30 days with a current of 50 mA·cm^(-2).We characterized the NiFe-PMA catalyst using various techniques,including Fourier transform infrared(FTIR)spectroscopy,Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),X-ray absorption spectroscopy(XAS),transmission electron microscopy(TEM),scanning electron microscopy(SEM),and inductively coupled plasma-optical emission spectrometry(ICP-OES).Our results showed that NiFe-PMA contains nickel,iron atoms,and both coordinated and uncoordinated carboxylate groups.Additionally,XPS data confirmed that carboxylate ligands could adjust the outer electronic structure of metal ions,resulting in the high valence state of Ni in NiFe-PMA.The result of XAS indicated that the nickel atoms present in the catalyst might be easier to maintain a higher chemical state.Further investigations using kinetic isotope effects(KIEs)and proton inventory revealed that the uncoordinated carboxylic protons played a crucial role in receiving protons during the OER,which promoted the proton transfer of the rate-determining step of the OER.Our novel electrocatalysts provide a new strategy for designing more active and cost-effective catalysts for the OER.
基金The authors acknowledge support from the National Nat-ural Science Foundation of China(51635007,51925503,51705179)Natural Science Foundation of Hubei Province of China(2020CFA028).
文摘Large,3D curved electronics are a trend of the microelectronic industry due to their unique ability to conformally coexist with complex surfaces while retaining the electronic functions of 2D planar integrated circuit technologies.However,these curved electronics present great challenges to the fabrication processes.Here,we propose a reconfigurable,mask-free,conformal fabrication strategy with a robot-like system,called robotized‘transfer-and-jet’printing,to assemble diverse electronic devices on complex surfaces.This novel method is a ground-breaking advance with the unique capability to integrate rigid chips,flexible electronics,and conformal circuits on complex surfaces.Critically,each process,including transfer printing,inkjet printing,and plasma treating,are mask-free,digitalized,and programmable.The robotization techniques,including measurement,surface reconstruction and localization,and path programming,break through the fundamental constraints of 2D planar microfabrication in the context of geometric shape and size.The transfer printing begins with the laser lift-off of rigid chips or flexible electronics from donor substrates,which are then transferred onto a curved surface via a dexterous robotic palm.Then the robotic electrohydrodynamic printing directly writes submicrometer structures on the curved surface.Their permutation and combination allow versatile conformal microfabrication.Finally,robotized hybrid printing is utilized to successfully fabricate a conformal heater and antenna on a spherical surface and a flexible smart sensing skin on a winged model,where the curved circuit,flexible capacitive and piezoelectric sensor arrays,and rigid digital–analog conversion chips are assembled.Robotized hybrid printing is an innovative printing technology,enabling additive,noncontact and digital microfabrication for 3D curved electronics.
基金Sponsored by the National Natural Science Foundation of China(Grant No.21277038)
文摘Sixty sediment samples were collected from the main Songhua River in three years. Twelve polybrominated diphenyl ether( PBDE) congeners( BDE17,28,47,66,99,100,153,154,138,183,and BDE-209) were detected to state the pollution situation. The results showed that the total concentration of total PBDEs ranges from 0. 424 to 23. 0 ng / g dry weight,with the mean of 3. 02 ng / g,and the total PBDEs concentration is at relative low level compared with those worldwide. The congener profile showed that BDE-209 is the dominant congener that accounts for more than 80. 1% of total PBDEs in sediments,followed by BDE-47 and BDE-99. These profiles are consistent with a high consumption of Deca-BDEs for the brominated flame retardant market in China. The results of spatial and seasonal observations indicated that local sources,temperature variation, and hydrologic conditions are significant factors on PBDEs concentrations. Hazard quotients suggested that PBDEs pose no potential risk to benthic organisms in detected area at present.
文摘The key objective of this paper is to improve the approximation of a sufficiently smooth nonperiodic function defined on a compact interval by proposing alternative forms of Fourier series expansions. Unlike in classical Fourier series, the expansion coefficients herein are explicitly dependent not only on the function itself, but also on its derivatives at the ends of the interval. Each of these series expansions can be made to converge faster at a desired polynomial rate. These results have useful implications to Fourier or harmonic analysis, solutions to differential equations and boundary value problems, data compression, and so on.
基金supported by the National Natural Science Foundation of China(Grant Nos.U1864207 and 51902232)。
文摘The rational modulation of electronic structure is highly desirable to develop an efficient alkaline hydrogen evolution reaction(HER)catalyst for renewable energy applications.Metal hydroxide such as Ni(OH)_(2) has been proven useful for promoting alkaline HER,but the performance remains unsatisfactory.Herein,the electronic structure of Ni(OH)_(2) is modulated by the interfacial electron rearrangement between Ni-Ni(OH)_(2) heterojunction.Combined experiments with DFT simulations,the electrons of Ni species accumulate to the interfacial Ni-Ni(OH)_(2) sites,which modifies the d band center for promoting conversion of hydrogen intermediates and narrows the energy gap for boosting charge transfer in the HER process.Thus,the integrated electrode exhibits an efficient HER performance to drive10 mA cm^(-2) at the overpotential of 72 mV with a low Tafel slope of 43 mV dec^(-1).Our work renders a valuable insight for understanding and rationally designing efficient catalysts in alkaline HER.
基金supported by the Fundamental Research Funds for the Central Universities of China(No.2572021BF02).
文摘Ultrasound-magnetic field coaxial hybrid Gas Tungsten Arc Welding(U-M-GTAW)is proposed as a means to control arc characteristics.The arc characteristics and the mechanism to change them,in an ultrasound-magnetic field coaxial hybrid GTAW,were studied by both experimental and theoretical analyses.The results showed that a periodic rotation and compression of the arc shape were obtained in U-M-GTAW and the arc energy was also enhanced.The most obvious compression of the arc shape in U-M-GTAW was obtained,compared with GTAW,M-GTAW and U-GTAW.At the same time,a periodic rotation of the arc was observed in U-M-GTAW.The geometric parameters of the arc shape in U-M-GTAW are reduced more than double compared with traditional GTAW.The arc voltage in the hybrid GTAW was increased,especially in the U-M-GTAW.The electromagnetic force and acoustic radiation force were the main factors for the change of arc characteristics in the U-M-GTAW.
基金This study was funded by the work is supported by the National Key R&D Program of China(2016YFC1401903)the Program for the Capacity Development of Shanghai Local Colleges No.20050501900+1 种基金Shanghai Education Development Fund Project(Grant NO.AASH2004)This work was funded by the Researchers Supporting Project No.(RSP2022R509)King Saud University,Riyadh,Saudi Arabia.
文摘Sea surface temperature (SST) is closely related to global climatechange, ocean ecosystem, and ocean disaster. Accurate prediction of SST isan urgent and challenging task. With a vast amount of ocean monitoring dataare continually collected, data-driven methods for SST time-series predictionshow promising results. However, they are limited by neglecting complexinteractions between SST and other ocean environmental factors, such as airtemperature and wind speed. This paper uses multi-factor time series SSTdata to propose a sequence-to-sequence network with two-module attention(TMA-Seq2seq) for long-term time series SST prediction. Specifically, TMASeq2seq is an LSTM-based encoder-decoder architecture facilitated by factorand temporal-attention modules and the input of multi-factor time series. Ittakes six-factor time series as the input, namely air temperature, air pressure,wind speed, wind direction, SST, and SST anomaly (SSTA). A factor attentionmodule is first designed to adaptively learn the effect of different factors onSST, followed by an encoder to extract factor-attention weighted features asfeature representations. And then, a temporal attention module is designedto adaptively select the hidden states of the encoder across all time steps tolearn more robust temporal relationships. The decoder follows the temporalattention module to decode the feature vector concatenated from the weightedfeatures and original input feature. Finally, we use a fully-connect layer tomap the feature into prediction results. With the two attention modules, ourmodel effectively improves the prediction accuracy of SST since it can notonly extract relevant factor features but also boost the long-term dependency.Extensive experiments on the datasets of China Coastal Sites (CCS) demonstrate that our proposed model outperforms other methods, reaching 98.29%in prediction accuracy (PACC) and 0.34 in root mean square error (RMSE).Moreover, SST prediction experiments in China’s East, South, and Yellow Seasite data show that the proposed model has strong robustness and multi-siteapplicability.
基金supported by the Research on Inheritance and Innovation of Experience(Integration of Tao and Shu)of Illustrious Senior Traditional Chinese Medicine Practitioners by adopting Multiple Research Methods(National Key R&D Program of China2018YFC1704100)+2 种基金Research on Methodology System and Paradigms for Mining and Inheriting Illustrious Senior Traditional Chinese Medicine Practitioners’Experience(2018YFC1704101)the National Natural Science Foundation of China(81373769)Fundamental Research Funds for the Central Universities(2018-JYBZZ-XS033).
文摘Objective:To investigate the association between gastrointestinal heat retention syndrome(GHRS)and adult chronic eczema.Methods:This caseecontrol study compared GHRS/GHRS accompanied by damp-heat syndrome(GHRSDHS)and other patient characteristics between subjects with(cases)and without chronic eczema(controls)to identify potential factors associated with this condition.Semi-structured questionnaires were used to collect data via face-to-face interviews.Participants were recruited from Dongzhimen Hospital affiliated with Beijing University of Chinese Medicine.A logistic regression analysis was performed on the collected data,and odds ratios(ORs)were calculated.Results:A total of 168 cases and 172 controls were recruited.Among the cases of adult chronic eczema,there were 79 subjects with GHRS and 68 with GHRS-DHS.Sex(P=.02,OR=0.54,95%confidence interval[CI]:0.32-0.91),GHRS(P=.04,OR=1.90,95%CI:1.02-3.51),GHRS-DHS(P<.001,OR=4.89,95%CI:2.36-10.15),high sweet food consumption(P=.04,OR=2.03,95%CI:1.03-3.97),and mental stress(P=.01,OR=2.37,95%CI:1.26-4.47)were each found to be associated with chronic eczema.Furthermore,GHRS had a weak positive correlation with eczema EASI severity as measured by the eczema area and severity index(EASI)(P=003).Conclusion:GHRS/GHRS-DHS may be associated with adult chronic eczema.In the future,prospective cohort studies with larger samples should be conducted to investigate the cause and effect association between GHRS and adult chronic eczema.
文摘Objectives: The purpose of this research is to determine the quantitative relationship between the peak wall stress of abdominal aortic aneurysm (AAA) and its clinical risk factors including its maximum diameter, asymmetry index, wall thickness and abnormal high blood pressure. Methods: The response surface experimental design with one response and four variables was used to design the experimental tests. Thirty experiments were performed through finite element analysis in order to obtain the designed response values. Results: A nonlinear multivariable regression function was developed based on the experimental data. Results demonstrated the inefficiency of traditional 5-cm criterion for estimating the rupture of AAA. The profound effect of wall thickness on the peak wall stress has been observed and validated by the existing publications. Conclusion: The conventional 5-cm criterion for estimating AAA rupture might induce biased prediction, and multiple clinical risk factors need to be considered in realistic clinical settings.
文摘Residual thermal stresses and warping of the anode-supported planar solid oxide fuel cell (SOFC) were estimated numerically. A 3D finite element (FE) model with viscoelastic constitutive equations was established to calculate the residual stress and warping for the cell. In the fabrication of the cells, some mechanical restriction was employed during the high-temperature treatment followed by a cooling stage in order to prevent the button cell from warping, and then from these specific boundaries and loading conditions, a FE simulation was used to calculate the distribution of the internal stresses in the cell. The results indicate that the concentration of compressive stress appears in the electrolyte layer, and that could cause interfacial micro-cracks or even cohesive failure. Furthermore, from the numerical study, the annealing time (or continuous cooling) is related to the residual stress in the material due to creeping. The compressive stress in the electrolyte layer can be reduced significantly by increasing the cooling time. Therefore, it is possible to optimize the annealing time in order to make the SOFCs flat and have less residual stress, improving the mechanical durability.
基金supported by the Fujian Provincial Science and Technology Cooperation Project(No.20210002)National Natural Science Foundation of China(No.31870994).
文摘Membrane filtration is one of the effective approaches to harvest microalgae for industrial biofuel production.However,during the filtration process,microalgae cells and extracellular organic matter(EOM)will deposit on the membrane surface leading to reversible membrane fouling that can be removed by physical methods.When hydrophobic EOM is adsorbed on the membrane surface or inside pores,it will build up a gel layer,causing irreversible membrane fouling.Irreversible fouling can only be removed using chemical methods that will decrease membrane lifespan and increase operational costs.Here,we introduce a versatile superhydrophilic membrane with photo-Fenton self-cleaning property,which can prevent the reversible fouling and remove the irreversible fouling.Tannic acid(TA)and 3-aminopropyltriethoxysilane(APTES)were co-deposited on the polyvinylidene fluoride(PVDF)membrane via Schiff base and Michael addition reactions,andβ-FeOOH nanorods were inlaid on the membrane surface by in situ mineralization.The water contact angle of the modified membrane is reduced from 120°to 0°Under 60 min visible light,the hydroxyl radical(·OH)generated by the photo-Fenton reaction degraded the irreversible fouling that blocked membrane pores.The irreversible fouling rates of modified membrane was reduced from 39.57%to 3.26%,compared with the original membrane.Microalgae harvesting results illustrated that the membrane has a high flux recovery rate(FRR)of 98.2%,showed excellent passive antifouling and active antifouling performance.We believe this work will spark a novel platform for optimizing energy-efficient microalgae harvesting separation membrane modules.In addition,this method of anti-fouling filtration for microorganisms can be extended to the industrial production of various bioenergy sources and will have very promising practical applications.
基金This work was financially supported by the Agency for Science,Technology and Research(A*STAR)under its AME Programmatic Funding Scheme of CyberPhysiochemical Interfaces Programme(Project No.A18A1b0045)。
文摘Next-generation electronics that are fused into the human body can play a key role in future intelligent communication,smart healthcare,and human enhancement applications.As a promising energy supply component for smart biointegrated electronics,environment-adaptive electrochemical energy storage(EES)devices with complementary adaptability and functions have garnered huge interest in the past decade.Owing to the advancements in autonomous chemistry,which regulate the constitutional dynamic networks in materials,EES devices have witnessed higher freedom of autonomous adaptability in terms of mechano-adaptable,biocompatibility,and stimuli-response properties for biointegrated and smart applications.In this mini-review,we summarize the recent progress in emerging environmentadaptive EES devices enabled by the constitutional dynamic network of mechanical adaptable materials,biocompatible materials,and stimuli-responsive supramolecular polymer materials.Finally,the challenges and perspectives of autonomous chemistry on the environment-adaptive EES devices are discussed.
文摘The pulsed-spray fluid-bed granulation (PSFBG) process was investigated and optimized using definitive scree ning design, a recently proposed new class of three-level desig n of experiment method. Such a design enabled quadratic models to be established that described the effect of six in put process parameters - inlet air temperature, inlet air humidity, binder spray rate, atomization pressure, pulse period, and pulse width - on the granule quality in a PSFBG process. Mathematical models of the mean particle size, relative size distribution width, production yield, and porosity were developed to quantify the relationships between the in flue ncing factors and critical quality attributes. On the basis of con strai nts on the desired granule properties, a design space for PSFBG was determined and ranges of the operating parameters were defined. An acceptable degree of prediction was confirmed by validation experiments, demonstrating the reliability and effectiveness of using definitive screening design to study the PSFBG process. This method can accelerate screening and optimization of this process within a large multidimensional design space.
基金ACKNOWLEDGMENTS This work was supported by the Major Research Plan of the National Natural Science Foundation of China （No. 91230118 and No.91330113） and the National Natural Science Foundation of China （No.11275259 and No. 61173060）.
基金supported in part by the National Key Research and Development Program of China(2021YFF1001204)the National Natural Science Foundation of China(32090065,31871649,32072080,32101742)+1 种基金the Horizon 2020 of European Union(EUCLEG/727312)Jiangsu Agriculture Science and Technology Innovation Fund(CX(22)2003)。
文摘Increasing plant photosynthetic capacity is a promising approach to boost yields,but it is particularly challenging in C3crops,such as soybean(Glycine max(L.)Merr.).Here,we identified GmFtsH25,encoding a member of the filamentation temperature-sensitive protein H protease family,as a major gene involved in soybean photosynthesis,using linkage mapping and a genome-wide association study.Overexpressing GmFtsH25 resulted in more grana thylakoid stacks in chloroplasts and increased photosynthetic efficiency and starch content,while knocking out GmFtsH25 produced the opposite phenotypes.GmFtsH25 interacted with photosystem I light harvesting complex 2(GmLHCa2),and this interaction may contribute to the observed enhanced photosynthesis.GmFtsH25 overexpression lines had superior yield traits,such as yield per plant,compared to the wild type and knockout lines.Additionally,we identified an elite haplotype of GmFtsH25,generated by natural mutations,which appears to have been selected during soybean domestication.Our study sheds light on the molecular mechanism by which GmFtsH25 modulates photosynthesis and provides a promising strategy for improving the yields of soybean and other crops.
