High-voltage transmission lines play a crucial role in facilitating the utilization of renewable energy in regions prone to desertification. The accumulation of atmospheric particles on the surface of these lines can ...High-voltage transmission lines play a crucial role in facilitating the utilization of renewable energy in regions prone to desertification. The accumulation of atmospheric particles on the surface of these lines can significantly impact corona discharge and wind-induced conductor displacement. Accurately quantifying the force exerted by particles adhering to conductor surfaces is essential for evaluating fouling conditions and making informed decisions. Therefore, this study investigates the changes in electric field intensity along branched conductors caused by various fouling layers and their resulting influence on the adhesion of dust particles. The findings indicate that as individual particle size increases, the field strength at the top of the particle gradually decreases and eventually stabilizes at approximately 49.22 k V/cm, which corresponds to a field strength approximately 1.96 times higher than that of an unpolluted transmission line. Furthermore,when particle spacing exceeds 15 times the particle size, the field strength around the transmission line gradually decreases and approaches the level observed on non-adhering surface. The electric field remains relatively stable. In a triangular arrangement of three particles, the maximum field strength at the tip of the fouling layer is approximately 1.44 times higher than that of double particles and 1.5 times higher compared to single particles. These results suggest that particles adhering to the transmission line have a greater affinity for adsorbing charged particles. Additionally, relevant numerical calculations demonstrate that in dry environments, the primary adhesion forces between particles and transmission lines follow an order of electrostatic force and van der Waals force. Specifically, at the minimum field strength, these forces are approximately74.73 times and 19.43 times stronger than the gravitational force acting on the particles.展开更多
The energy spectrum of energetic electrons is a key factor representing the dynamic variations of Earth’s Van Allen radiation belts.Increased measurements have indicated that the commonly used Maxwellian and Kappa di...The energy spectrum of energetic electrons is a key factor representing the dynamic variations of Earth’s Van Allen radiation belts.Increased measurements have indicated that the commonly used Maxwellian and Kappa distributions are inadequate for capturing the realistic spectral distributions of radiation belt electrons.Here we adopt the Kappa-type(KT)distribution as the fitting function and perform a statistical analysis to investigate the radiation belt electron flux spectra observed by the Van Allen Probes.By calculating the optimal values of the key KT distribution parameters(i.e.,κandθ2)from the observed spectral shapes,we fit the radiation belt electron fluxes at different L-shells under different geomagnetic conditions.In this manner,we obtain typical values of the KT distribution parameters,which are statistically feasible for modeling the radiation belt electron flux profiles during either geomagnetically quiet or active periods.A comparison of the KT distribution model results with those using the Maxwellian or Kappa distribution reveals the advantage of the KT distribution for studying the overall properties of the radiation belt electron spectral distribution,which has important implications for deepening the current understanding of the radiation belt electron dynamics under evolving geomagnetic conditions.展开更多
In this paper, an adaptive proportional-derivative sliding mode control(APD-SMC) law, is proposed for 2D underactuated overhead crane systems. The proposed controller has the advantages of simple structure, easy to im...In this paper, an adaptive proportional-derivative sliding mode control(APD-SMC) law, is proposed for 2D underactuated overhead crane systems. The proposed controller has the advantages of simple structure, easy to implement of PD control, strong robustness of SMC with respect to external disturbances and uncertain system parameters, and adaptation for unknown system dynamics associated with the feedforward parts. In the proposed APD-SMC law, the PD control part is used to stabilize the controlled system, the SMC part is used to compensate the external disturbances and system uncertainties,and the adaptive control part is utilized to estimate the unknown system parameters. The coupling behavior between the trolley movement and the payload swing is enhanced and, therefore, the transient performance of the proposed controller is improved.The Lyapunov techniques and the La Salle's invariance theorem are employed in to support the theoretical derivations. Experimental results are provided to validate the superior performance of the proposed control law.展开更多
Radiation belt electron dropouts indicate electron flux decay to the background level during geomagnetic storms,which is commonly attributed to the effects of wave-induced pitch angle scattering and magnetopause shado...Radiation belt electron dropouts indicate electron flux decay to the background level during geomagnetic storms,which is commonly attributed to the effects of wave-induced pitch angle scattering and magnetopause shadowing.To investigate the loss mechanisms of radiation belt electron dropouts triggered by a solar wind dynamic pressure pulse event on 12 September 2014,we comprehensively analyzed the particle and wave measurements from Van Allen Probes.The dropout event was divided into three periods:before the storm,the initial phase of the storm,and the main phase of the storm.The electron pitch angle distributions(PADs)and electron flux dropouts during the initial and main phases of this storm were investigated,and the evolution of the radial profile of electron phase space density(PSD)and the(μ,K)dependence of electron PSD dropouts(whereμ,K,and L^*are the three adiabatic invariants)were analyzed.The energy-independent decay of electrons at L>4.5 was accompanied by butterfly PADs,suggesting that the magnetopause shadowing process may be the major loss mechanism during the initial phase of the storm at L>4.5.The features of electron dropouts and 90°-peaked PADs were observed only for>1 MeV electrons at L<4,indicating that the wave-induced scattering effect may dominate the electron loss processes at the lower L-shell during the main phase of the storm.Evaluations of the(μ,K)dependence of electron PSD drops and calculations of the minimum electron resonant energies of H+-band electromagnetic ion cyclotron(EMIC)waves support the scenario that the observed PSD drop peaks around L^*=3.9 may be caused mainly by the scattering of EMIC waves,whereas the drop peaks around L^*=4.6 may result from a combination of EMIC wave scattering and outward radial diffusion.展开更多
Ni-rich layered material is a kind of high-capacity cathode to meet the requirement of electric vehicles.As for the typical LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material,the particle formation is significant for electroche...Ni-rich layered material is a kind of high-capacity cathode to meet the requirement of electric vehicles.As for the typical LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material,the particle formation is significant for electrochemical properties of the cathode.In this work,the structure,morphology,and electrochemical performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) secondary particles and single crystals were systematically studied.A lower Ni^(2+)/Ni^(3+)molar ratio of 0.66 and a lower residual alkali content of 0.228wt%were achieved on the surface of the single crystals.In addition,the single crystals showed a discharge capacity of 191.6 mAh/g at 0.2 C(~12 mAh/g lower than that of the secondary particles)and enhanced the electrochemical stability,especially when cycled at 50℃ and in a wider electrochemical window(between 3.0 and 4.4 V vs.Li+/Li).The LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) secondary particles were suitable for applications requiring high specific capacity,whereas single crystals exhibited better stability,indicating that they are more suitable for use in long life requested devices.展开更多
Global mitigative and adaptive efforts have not been able to effectively address the adverse impacts caused by climate change.Therefore,a direct solution is needed to address the significant resulting loss and damage(...Global mitigative and adaptive efforts have not been able to effectively address the adverse impacts caused by climate change.Therefore,a direct solution is needed to address the significant resulting loss and damage(L&D).During the United Nations Framework Convention on Climate Change held in Doha in 2012,the issue of responding to L&D arising from climate change gained sudden traction and became one of the key issues that affected the outcome of the convention.In this paper,a study on the definition and connotations of L&D arising from climate change was conducted,together with an analysis of its relationship with related concepts,namely impacts,vulnerability,and risks.This led to the proposal of an L&D conceptual model that is more comprehensive,with the recognition of the need to address the issue through effective supplementation of existing mitigative and adaptive efforts.A systematic elaboration of an L&D response mechanism was made based on politics,law,and the market,leading to a preliminary presentation of a possible format for an L&D mechanism.Potential academic research directions for L&D were also proposed that could serve as references for the establishment of international and national L&D response mechanisms and related research.展开更多
Background:To evaluate the mechanism of Chinese patent drug Xuebijing(XBJ)injection in the treatment of a new coronavirus disease 2019(COVID-19)based on network pharmacology and molecular docking technology.Methods:Th...Background:To evaluate the mechanism of Chinese patent drug Xuebijing(XBJ)injection in the treatment of a new coronavirus disease 2019(COVID-19)based on network pharmacology and molecular docking technology.Methods:The TCMSP database was employed to collect and screen the active ingredients of the Chinese herb contained in the XBJ injection.The GeneCards database and STRING database were applied to collect and expand the targets of COVID-19 and compare and screen the related targets of COVID-19 by XBJ injection.Cytoscape was employed to build a network connecting Chinese medicine,compounds,targets,disease,and topology analysis was performed via the Network Analyzer to screen the key ingredients and targets.The software of Schrödinger molecular docking was used to verify the binding activity of the key ingredients of XBJ injection and the key targets of COVID-19.Metascape platform and DAVID database were utilized to conduct Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes analysis on the key targets of COVID-19 treated by XBJ injection.Results:Eight key compounds and 15 key targets were screened and verified by molecular docking;these key compounds included luteolin,quercetin,baicalein,and kaempferol.The key targets included DPP4,AR,ESR1,CALM1,and protein kinase 1.Gene Ontology analysis involved an apoptosis and hypoxia reaction and the changes in blood vessel morphology.Kyoto Encyclopedia of Genes and Genomes analysis involved signaling pathways of hypoxia inducible factor-1,VEGF,and PI3K/AKT/NF-κB.Conclusion:The mechanism of XBJ injection when used to treat COVID-19 should be further investigated as the key compounds in XBJ regulated the expression of key targets such as protein kinase 1,VEGF-A,B-cell lymphoma-2,and TNF,which affected the COVID-19 receptors such as angiotensin-converting enzyme 2 and signaling pathways like hypoxia inducible factor-1,PI3K-Akt,and NF-κB,which alleviated the inflammation,respiratory distress,and hypoxia caused by COVID-19 infection.展开更多
Background Patients with major depressive disorder(MDD)may have an abnormal peripheral body temperature rhythm,but its relationship with suicidal risk and the response to treatment with antidepressants remain unknown....Background Patients with major depressive disorder(MDD)may have an abnormal peripheral body temperature rhythm,but its relationship with suicidal risk and the response to treatment with antidepressants remain unknown.Aims This study aimed to investigate the feature of peripheral body temperature in patients with MDD and its relationship with suicide risk before and after treatment with antidepressants.Methods This is a prospective case-control study.Patients diagnosed as MDD were enrolled into MDD group.Healthy subjects who matched in terms of gender,age and body mass index were enrolled into normal control(NC)group.The 24-hour peripheral body temperatures were monitored by TM’Holter the next day after assessment.Patients with MDD were re-assessed after a 2-week treatment with antidepressants.All temperature data were fitted into cosine curves by Python.Result There were 41 patients with MDD,and 21 NC participants enrolled and completed the baseline assessments before the treatment.Patients with MDD were further divided into subgroup of with suicide risk or without suicide risk.In patients with MDD,the mesor of peripheral body temperature rhythm was higher in both patients with(36.17(0.30))and without suicide risk(36.22(0.27))than the mesor in NC participants before treatment(35.84(0.38),Z=11.82,p=0.003,Kruskal-Wallis test).The phase-delay of temperature before treatment was greater in patients with MDD with suicidal risk(4.71(1.68))in comparison with those without suicidal risk(3.05(2.19))and NC participants(3.19(1.82),Z=9.68,p=0.008,Kruskal-Wallis test).Moreover,phase-delay of temperature was associated with suicide risk in patients with MDD before treatment(OR=1.046,95%CI:1.009 to 1.085,p=0.015,unadjusted;OR=1.080,95%CI:1.020 to 1.144,p=0.009,adjusted by age and sex).Conclusion Patients with MDD might have abnormal peripheral body temperature.The abnormal phase-delay of peripheral body temperature may indicate suicide risk in patients with MDD,depending on validation in large-scale cohorts.展开更多
Trans-4-hydroxy-2-hexenal(4-HHE) and trans-4-hydroxy-2-nonenal(4-HNE) are secondary lipid peroxidation products in edible oils, which are cytotoxic and genotoxic. They could covalently bind with protein, phospholipids...Trans-4-hydroxy-2-hexenal(4-HHE) and trans-4-hydroxy-2-nonenal(4-HNE) are secondary lipid peroxidation products in edible oils, which are cytotoxic and genotoxic. They could covalently bind with protein, phospholipids and DNA, further disrupting the normal function of liver, lung and brain.Derivation process was generally conducted during pretreatment before detection and quantification of 4-HHE and 4-HNE. However, the derivation procedures were time consuming and chemical degradation may occur during the process. Hence, this paper aims to establish a simple solid phase extractionhigh performance liquid chromatography(SPE-HPLC) method to determine the 4-HHE and 4-HNE contents in thermally treated soybean oil. C18 solid phase extraction was applied in the pretreatment process. Firstly, the reliability of the method was evaluated. Good linearity was observed in the range of 0.1–0.5 μg/m L and 0.5–10 μg/m L for 4-HHE and 4-HNE. The limit of detection(LOD) of 4-HHE and 4-HNE were 0.0486 and 0.0129 μg/m L, respectively. And the limit of quantitation(LOQ) of4-HHE and 4-HNE were 0.1458 and 0.0431 μg/m L, respectively. Recovery rate were in the range of89.11%–91.58% and 71.83%–79.40% for 4-HHE and 4-HNE, respectively. The method achieved the extraction, purification and detection of 4-HHE and 4-HNE simultaneously and had the advantages of simple operation, effectiveness, high precision, good repeatability. Then, the method was applied to monitor the concentrations of 4-HHE and 4-HNE in soybean oil heated at 180 °C for 40 h. The contents of 4-HHE and 4-HNE were 0–0.32 μg/g and 0–6.97 μg/g, respectively, which provided guidance for evaluating health risks of thermally treated soybean oil during heating.展开更多
Loss and damage(L&D) from climate change has threatened the sustainable development of humankind,while the progress of mitigative and adaptive measures carried out under the international multilateral framework ha...Loss and damage(L&D) from climate change has threatened the sustainable development of humankind,while the progress of mitigative and adaptive measures carried out under the international multilateral framework has been slow.The scientific community and policymakers have placed increasing emphasis on the international L&D response mechanism as a potential direct solution.This paper reviewed the origins of such a mechanism,with an in-depth analysis of the related connotations.A review of the existing situation in China on work related to L&D arising from climate change was conducted,followed by a summary of the findings.Finally,measures and recommendations to improve China's efforts were proposed in this issue.展开更多
Gliadins are the major components of storage proteins in wheat and play an important role in determining the extensibility properties of dough.In the present work,six novel full-length γ-gliadin genes were cloned fro...Gliadins are the major components of storage proteins in wheat and play an important role in determining the extensibility properties of dough.In the present work,six novel full-length γ-gliadin genes were cloned from the C genome of Aegilops markgrafii using a PCR-based strategy.Analysis of the deduced amino acid sequences showed that the cloned genes had primary structures that were similar,but not identical,to published γ-gliadins from other wheat-related species.The lengths of the open reading frames(ORFs)ranged from 909 to 963 bp,and the repetitive and glutamine-rich domains were mainly responsible for the size of the proteins.An extra cysteine residue was present in the repetitive domain of sequence JX566513.All amino acid sequences of γ-gliadin genes from Ae.markgrafii were searched for the five peptides identified as T cell stimulatory epitopes in celiac disease(CD)patients.Peptide Gliγ-3 was present in sequences JX566513 and JX566514.Peptide Gliγ-5 was present only in JX566513.The otherγ-gliadins contained no toxic epitopes.These results provide information to better understand the use of Ae.markgrafii in wheat breeding and the evolutionary relationship of theγ-gliadin genes in Ae.markgrafii and other Triticeae species.展开更多
We report a representative concurrent event of four wave modes at L≈5.0,including electrostatic electron cyclotron harmonic(ECH)waves,exohiss,magnetosonic(MS)waves,and electromagnetic ion cyclotron(EMIC)waves,based o...We report a representative concurrent event of four wave modes at L≈5.0,including electrostatic electron cyclotron harmonic(ECH)waves,exohiss,magnetosonic(MS)waves,and electromagnetic ion cyclotron(EMIC)waves,based on the observations from Van Allen Probe A on October 15,2015.The diffusion coefficients induced by these waves are calculated by using both the Full Diffusion Code and test particle simulations.Moreover,the scattering effects of these waves on energetic electrons are simulated by using a two-dimensional Fokker-Planck diffusion model.The results show that ECH waves mainly scatter low-pitch-angle(<20°)electrons at 0.1-10 keV;exohiss can significantly scatter hundreds of kiloelectron volt electrons to form a reversed energy spectrum;MS waves mainly affect high-pitch-angle electrons(>60°);and EMIC waves scatter only>5 MeV electrons.The combined scattering effects of exohiss and MS waves are stronger than those of exohiss alone.The top-hat pitch angle distributions produced by exohiss are relaxed after adding the effect of MS waves.Because the energies of electrons scattered by ECH waves and EMIC waves are much lower and higher than those scattered by exohiss and MS waves,respectively,the combined scattering effects with the addition of ECH and EMIC waves show little difference from the results for the combination of MS waves and exohiss.These results suggest that distinct wave modes can occur simultaneously and scatter electrons in combination or individually,which requires careful consideration in future global simulations of the complex dynamics of radiation belt energetic electrons.展开更多
Severe acute respiratory syndrome coronavirus 2(SARS-Co V-2)is the etiologic agent responsible for the global coronavirus disease 2019(COVID-19)pandemic.Numerous studies have demonstrated that cardiovascular disease m...Severe acute respiratory syndrome coronavirus 2(SARS-Co V-2)is the etiologic agent responsible for the global coronavirus disease 2019(COVID-19)pandemic.Numerous studies have demonstrated that cardiovascular disease may affect COVID-19 progression.In the present study,we investigated the effect of hypertension on viral replication and COVID-19 progression using a hypertensive mouse model infected with SARS-Co V-2.Results revealed that SARS-Co V-2 replication was delayed in hypertensive mouse lungs.In contrast,SARS-Co V-2 replication in hypertensive mice treated with the antihypertensive drug captopril demonstrated similar virus replication as SARS-Co V-2-infected normotensive mice.展开更多
Tailward ion outflows in the Martian-induced magnetotail are known to be one of the major channels for Martian atmospheric escape.On the basis of nearly 6.5 years of observations from the Mars Atmosphere and Volatile ...Tailward ion outflows in the Martian-induced magnetotail are known to be one of the major channels for Martian atmospheric escape.On the basis of nearly 6.5 years of observations from the Mars Atmosphere and Volatile EvolutioN(MAVEN)mission,we investigate the statistical distribution of tailward and Marsward fluxes of heavy ions(i.e.,O^(+),and O_(2)^(+))in the near-Mars magnetotail and explore their characteristic responses to the corotating interaction region(CIR),solar wind dynamic pressure,and local magnetic field intensity.Our results show that the tailward fluxes of oxygen ions and molecular oxygen ions in the magnetotail are significantly greater than their Marsward fluxes and that the tailward flux of molecular oxygen ions is generally larger than that of oxygen ions.Furthermore,the tailward ion flux distribution exhibits dependence on the CIR,solar wind dynamic pressure,and local magnetic field strength in a manner stronger than the Marsward ion flux distribution.According to the distribution of tailward ion fluxes,we calculate the corresponding escape rates of heavy ions and show that when the CIR occurs,the total escape rates of oxygen ions and molecular oxygen ions increase by a factor of~2 and~1.2,respectively.We also find that the escape rates of heavy ions increase with the enhancement of solar wind dynamic pressure,whereas the overall effect of the local magnetic field is relatively weak.Our study has important implications for improved understanding of the underlying mechanisms responsible for the Martian atmospheric escape and the evolution of the Martian atmospheric climate.展开更多
The finite element method has been increasingly adopted to study the biomechanical behavior of biologic structures. Once the finite element mesh has been generated from CT data set, the assignment of bone tissue’s ma...The finite element method has been increasingly adopted to study the biomechanical behavior of biologic structures. Once the finite element mesh has been generated from CT data set, the assignment of bone tissue’s material properties to each element is a fundamental step in the generation of individualized or subject-specific finite element models. The aim of this work is to simulate the inhomogeneous and anisotropic material properties of femur using the finite element method. A program is developed to read a CT data set as well as the finite element mesh generated from it, and to assign to each element of the mesh the material properties derived from the bone tissue density at the element location. Moreover, for cancellous bone in femoral neck and cortical bone in femoral stem, the principal orientations of transverse isotropy were defined based on the tra-becular structures and the haversian system respectively.展开更多
By temperature normalization of the concept of equivalent damage stress proposed by Lemaitre, a new concept of relative damage stress has been put forward as the dominant mechanical factor for the failure of soldered ...By temperature normalization of the concept of equivalent damage stress proposed by Lemaitre, a new concept of relative damage stress has been put forward as the dominant mechanical factor for the failure of soldered joints under temperature cycling. Finite element numerical simulation results showed that the highest value of relative damage stress occurred at the high temperature hold time during temperature cycling history.展开更多
To systematically validate and calibrate the theory and technology of the deep in-situ conditionpreserved coring, the in-situ conditions at different depths should be simulated, and the full-size coring tests should b...To systematically validate and calibrate the theory and technology of the deep in-situ conditionpreserved coring, the in-situ conditions at different depths should be simulated, and the full-size coring tests should be carried out in this simulated environment. Therefore, a deep-rock in-situ conditionpreserved coring calibration platform was designed and developed. The self-tightening sealing structure and the quick-disassembly structure were designed on the basis of an innovative segmented nonuniformdiameter structure, which was a breakthrough from the traditional high-pressure vessel frame and was verified by finite element simulation and actual testing under extreme working conditions, respectively.To simulate the actual deep in-situ environment with a temperature of 150℃ and pressure of 140 MPa for a large Φ450 mm×H1400 mm core, temperature and pressure control systems were designed by coupling, and a pre-embedded high-pressure-resistant temperature sensor was designed. Finally, highprecision assembly automation, complex movement coordination of the coring device with the platform,and rotary dynamic sealing were achieved by utilizing the combination of adaptive cabin body servo control and an adaptive mechanical structure in a limited space, laying a solid foundation for the calibration of in-situ condition-preserved coring.展开更多
Milk allergy is a common allergic reaction found in infants and young children,most of them appear tolerance after growing up.In this study,infant formula was digested by simulated in vitro digestion method.The potent...Milk allergy is a common allergic reaction found in infants and young children,most of them appear tolerance after growing up.In this study,infant formula was digested by simulated in vitro digestion method.The potential non-allergenic peptides were further screened from undigested products by exclusion of the known epitopes fromβ-lactoglobulin(BLG)andα-lactalbumin(ALA).These potential non-allergenic peptides were synthesized and their transferability were determined by Caco-2 cell monolayer model.Finally,the potential allergenicity were evaluated by KU812 cell degranulation model.The results showed that 7 peptides were screened as non-allergenic sequences,among which were 3 from ALA and 4 from BLG.The Caco-2 cell model showed that all the synthetic peptides were absorbed and transported well.However,only peptide BLG_(107-118)showed potential allegencity by KU812 model.In conclusion,6 peptides,including ALA_(29-51),ALA_(80-90),ALA_(94-103),BLG_(1-20),BLG_(24-50),and BLG_(123-139)were evaluated as hypoallergenic peptides,which could be used for candidates of peptides inducing immune tolerance for persons with milk allergy.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No.12064034)the Leading Talents Program of Science and Technology Innovation in Ningxia Hui Autonomous Region,China (Grant No.2020GKLRLX08)+2 种基金the Natural Science Foundation of Ningxia Hui Auatonomous Region,China (Grant Nos.2022AAC03643,2022AAC03117,and 2018AAC03029)the Major Science and Technology Project of Ningxia Hui Autonomous Region,China (Grant No.2022BDE03006)the Natural Science Project of the Higher Education Institutions of Ningxia Hui Autonomous Region,China (Grant No.13-1069)。
文摘High-voltage transmission lines play a crucial role in facilitating the utilization of renewable energy in regions prone to desertification. The accumulation of atmospheric particles on the surface of these lines can significantly impact corona discharge and wind-induced conductor displacement. Accurately quantifying the force exerted by particles adhering to conductor surfaces is essential for evaluating fouling conditions and making informed decisions. Therefore, this study investigates the changes in electric field intensity along branched conductors caused by various fouling layers and their resulting influence on the adhesion of dust particles. The findings indicate that as individual particle size increases, the field strength at the top of the particle gradually decreases and eventually stabilizes at approximately 49.22 k V/cm, which corresponds to a field strength approximately 1.96 times higher than that of an unpolluted transmission line. Furthermore,when particle spacing exceeds 15 times the particle size, the field strength around the transmission line gradually decreases and approaches the level observed on non-adhering surface. The electric field remains relatively stable. In a triangular arrangement of three particles, the maximum field strength at the tip of the fouling layer is approximately 1.44 times higher than that of double particles and 1.5 times higher compared to single particles. These results suggest that particles adhering to the transmission line have a greater affinity for adsorbing charged particles. Additionally, relevant numerical calculations demonstrate that in dry environments, the primary adhesion forces between particles and transmission lines follow an order of electrostatic force and van der Waals force. Specifically, at the minimum field strength, these forces are approximately74.73 times and 19.43 times stronger than the gravitational force acting on the particles.
基金the National Natural Science Foundation of China(Grant Nos.42188101,42025404,41974186,42174188,and 42204160)the National Key R&D Program of China(Grant No.2022YFF0503700)+2 种基金the B-type Strategic Priority Program of the Chinese Academy of Sciences(Grant No.XDB41000000)the Fundamental Research Funds for the Central Universities(Grant Nos.2042022kf1016 and 2042023kf1025)the China Postdoctoral Science Foundation(Grant No.2022M722447)。
文摘The energy spectrum of energetic electrons is a key factor representing the dynamic variations of Earth’s Van Allen radiation belts.Increased measurements have indicated that the commonly used Maxwellian and Kappa distributions are inadequate for capturing the realistic spectral distributions of radiation belt electrons.Here we adopt the Kappa-type(KT)distribution as the fitting function and perform a statistical analysis to investigate the radiation belt electron flux spectra observed by the Van Allen Probes.By calculating the optimal values of the key KT distribution parameters(i.e.,κandθ2)from the observed spectral shapes,we fit the radiation belt electron fluxes at different L-shells under different geomagnetic conditions.In this manner,we obtain typical values of the KT distribution parameters,which are statistically feasible for modeling the radiation belt electron flux profiles during either geomagnetically quiet or active periods.A comparison of the KT distribution model results with those using the Maxwellian or Kappa distribution reveals the advantage of the KT distribution for studying the overall properties of the radiation belt electron spectral distribution,which has important implications for deepening the current understanding of the radiation belt electron dynamics under evolving geomagnetic conditions.
基金supported in part by the National High Technology Research and Development Program of China(863 Program)(2015AA042307)Shandong Provincial Scientific and Technological Development Foundation(2014GGX103038)+3 种基金Shandong Provincial Independent Innovation and Achievement Transformation Special Foundation(2015ZDXX0101E01)National Natural Science Fundation of China(NSFC)Joint Fund of Shandong Province(U1706228)the Fundamental Research Funds of Shandong University(2015JC027)
文摘In this paper, an adaptive proportional-derivative sliding mode control(APD-SMC) law, is proposed for 2D underactuated overhead crane systems. The proposed controller has the advantages of simple structure, easy to implement of PD control, strong robustness of SMC with respect to external disturbances and uncertain system parameters, and adaptation for unknown system dynamics associated with the feedforward parts. In the proposed APD-SMC law, the PD control part is used to stabilize the controlled system, the SMC part is used to compensate the external disturbances and system uncertainties,and the adaptive control part is utilized to estimate the unknown system parameters. The coupling behavior between the trolley movement and the payload swing is enhanced and, therefore, the transient performance of the proposed controller is improved.The Lyapunov techniques and the La Salle's invariance theorem are employed in to support the theoretical derivations. Experimental results are provided to validate the superior performance of the proposed control law.
基金This work was supported by the B-type Strategic Priority Program of the Chinese Academy of Sciences(grant no.XDB41000000)the National Natural Science Foundation of China(grant nos.42025404,41704162,41974186,41674163,41904144,41904143)+1 种基金the pre-research projects on Civil Aerospace Technologies(grant nos.D020303,D020308,D020104)the China National Space Administration,and the China Postdoctoral Science Foundation Project(grant no.2019M662700).We also acknowledge the Van Allen Probes mission,particularly the ECT and EMFISIS team,for providing particle and wave data.The electron flux data were obtained from http://www.rbsp-ect.lanl.gov/data_pub/.The wave data from the EMFISIS instrument were obtained from http://emfisis.physics.uiowa.edu/data/index.The solar wind parameters and geomagnetic indices were obtained from the online OMNIWeb(http://omniweb.gsfc.nasa.gov/).
文摘Radiation belt electron dropouts indicate electron flux decay to the background level during geomagnetic storms,which is commonly attributed to the effects of wave-induced pitch angle scattering and magnetopause shadowing.To investigate the loss mechanisms of radiation belt electron dropouts triggered by a solar wind dynamic pressure pulse event on 12 September 2014,we comprehensively analyzed the particle and wave measurements from Van Allen Probes.The dropout event was divided into three periods:before the storm,the initial phase of the storm,and the main phase of the storm.The electron pitch angle distributions(PADs)and electron flux dropouts during the initial and main phases of this storm were investigated,and the evolution of the radial profile of electron phase space density(PSD)and the(μ,K)dependence of electron PSD dropouts(whereμ,K,and L^*are the three adiabatic invariants)were analyzed.The energy-independent decay of electrons at L>4.5 was accompanied by butterfly PADs,suggesting that the magnetopause shadowing process may be the major loss mechanism during the initial phase of the storm at L>4.5.The features of electron dropouts and 90°-peaked PADs were observed only for>1 MeV electrons at L<4,indicating that the wave-induced scattering effect may dominate the electron loss processes at the lower L-shell during the main phase of the storm.Evaluations of the(μ,K)dependence of electron PSD drops and calculations of the minimum electron resonant energies of H+-band electromagnetic ion cyclotron(EMIC)waves support the scenario that the observed PSD drop peaks around L^*=3.9 may be caused mainly by the scattering of EMIC waves,whereas the drop peaks around L^*=4.6 may result from a combination of EMIC wave scattering and outward radial diffusion.
基金This work was financially supported by the National Natural Science Foundation of China(No.21706292)Hunan Provincial Science and Technology Plan Project,China(No.2016TP1007)+1 种基金Hunan Provincial Natural Science Foundation of China(No.2020JJ4107)Kai Han acknowledges the support from Innovation-Driven Project of Central South University(No.2020CX037).
文摘Ni-rich layered material is a kind of high-capacity cathode to meet the requirement of electric vehicles.As for the typical LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material,the particle formation is significant for electrochemical properties of the cathode.In this work,the structure,morphology,and electrochemical performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) secondary particles and single crystals were systematically studied.A lower Ni^(2+)/Ni^(3+)molar ratio of 0.66 and a lower residual alkali content of 0.228wt%were achieved on the surface of the single crystals.In addition,the single crystals showed a discharge capacity of 191.6 mAh/g at 0.2 C(~12 mAh/g lower than that of the secondary particles)and enhanced the electrochemical stability,especially when cycled at 50℃ and in a wider electrochemical window(between 3.0 and 4.4 V vs.Li+/Li).The LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) secondary particles were suitable for applications requiring high specific capacity,whereas single crystals exhibited better stability,indicating that they are more suitable for use in long life requested devices.
基金supported by National Key Technologies R&D Program[2012BAC19B01]National Key Technologies R&D Program[2012BAC20B04]+1 种基金National Key Technologies R&D Program[2012BAC09B04]China Clean Development Mechanism Fund[1113113]
文摘Global mitigative and adaptive efforts have not been able to effectively address the adverse impacts caused by climate change.Therefore,a direct solution is needed to address the significant resulting loss and damage(L&D).During the United Nations Framework Convention on Climate Change held in Doha in 2012,the issue of responding to L&D arising from climate change gained sudden traction and became one of the key issues that affected the outcome of the convention.In this paper,a study on the definition and connotations of L&D arising from climate change was conducted,together with an analysis of its relationship with related concepts,namely impacts,vulnerability,and risks.This led to the proposal of an L&D conceptual model that is more comprehensive,with the recognition of the need to address the issue through effective supplementation of existing mitigative and adaptive efforts.A systematic elaboration of an L&D response mechanism was made based on politics,law,and the market,leading to a preliminary presentation of a possible format for an L&D mechanism.Potential academic research directions for L&D were also proposed that could serve as references for the establishment of international and national L&D response mechanisms and related research.
基金This study was supported by the Foundation of Health Commission of Hebei Province(20190123)the Natural Science Foundation of Hebei Province of China(H2018201179).
文摘Background:To evaluate the mechanism of Chinese patent drug Xuebijing(XBJ)injection in the treatment of a new coronavirus disease 2019(COVID-19)based on network pharmacology and molecular docking technology.Methods:The TCMSP database was employed to collect and screen the active ingredients of the Chinese herb contained in the XBJ injection.The GeneCards database and STRING database were applied to collect and expand the targets of COVID-19 and compare and screen the related targets of COVID-19 by XBJ injection.Cytoscape was employed to build a network connecting Chinese medicine,compounds,targets,disease,and topology analysis was performed via the Network Analyzer to screen the key ingredients and targets.The software of Schrödinger molecular docking was used to verify the binding activity of the key ingredients of XBJ injection and the key targets of COVID-19.Metascape platform and DAVID database were utilized to conduct Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes analysis on the key targets of COVID-19 treated by XBJ injection.Results:Eight key compounds and 15 key targets were screened and verified by molecular docking;these key compounds included luteolin,quercetin,baicalein,and kaempferol.The key targets included DPP4,AR,ESR1,CALM1,and protein kinase 1.Gene Ontology analysis involved an apoptosis and hypoxia reaction and the changes in blood vessel morphology.Kyoto Encyclopedia of Genes and Genomes analysis involved signaling pathways of hypoxia inducible factor-1,VEGF,and PI3K/AKT/NF-κB.Conclusion:The mechanism of XBJ injection when used to treat COVID-19 should be further investigated as the key compounds in XBJ regulated the expression of key targets such as protein kinase 1,VEGF-A,B-cell lymphoma-2,and TNF,which affected the COVID-19 receptors such as angiotensin-converting enzyme 2 and signaling pathways like hypoxia inducible factor-1,PI3K-Akt,and NF-κB,which alleviated the inflammation,respiratory distress,and hypoxia caused by COVID-19 infection.
基金This work was supported by National Natural Science Foundation of China(81720108012,81571034)Fundamental Research Funds for the Central Universities(22120180112).
文摘Background Patients with major depressive disorder(MDD)may have an abnormal peripheral body temperature rhythm,but its relationship with suicidal risk and the response to treatment with antidepressants remain unknown.Aims This study aimed to investigate the feature of peripheral body temperature in patients with MDD and its relationship with suicide risk before and after treatment with antidepressants.Methods This is a prospective case-control study.Patients diagnosed as MDD were enrolled into MDD group.Healthy subjects who matched in terms of gender,age and body mass index were enrolled into normal control(NC)group.The 24-hour peripheral body temperatures were monitored by TM’Holter the next day after assessment.Patients with MDD were re-assessed after a 2-week treatment with antidepressants.All temperature data were fitted into cosine curves by Python.Result There were 41 patients with MDD,and 21 NC participants enrolled and completed the baseline assessments before the treatment.Patients with MDD were further divided into subgroup of with suicide risk or without suicide risk.In patients with MDD,the mesor of peripheral body temperature rhythm was higher in both patients with(36.17(0.30))and without suicide risk(36.22(0.27))than the mesor in NC participants before treatment(35.84(0.38),Z=11.82,p=0.003,Kruskal-Wallis test).The phase-delay of temperature before treatment was greater in patients with MDD with suicidal risk(4.71(1.68))in comparison with those without suicidal risk(3.05(2.19))and NC participants(3.19(1.82),Z=9.68,p=0.008,Kruskal-Wallis test).Moreover,phase-delay of temperature was associated with suicide risk in patients with MDD before treatment(OR=1.046,95%CI:1.009 to 1.085,p=0.015,unadjusted;OR=1.080,95%CI:1.020 to 1.144,p=0.009,adjusted by age and sex).Conclusion Patients with MDD might have abnormal peripheral body temperature.The abnormal phase-delay of peripheral body temperature may indicate suicide risk in patients with MDD,depending on validation in large-scale cohorts.
基金supported by grants from the National Natural Science Foundation of China(No.31471668)。
文摘Trans-4-hydroxy-2-hexenal(4-HHE) and trans-4-hydroxy-2-nonenal(4-HNE) are secondary lipid peroxidation products in edible oils, which are cytotoxic and genotoxic. They could covalently bind with protein, phospholipids and DNA, further disrupting the normal function of liver, lung and brain.Derivation process was generally conducted during pretreatment before detection and quantification of 4-HHE and 4-HNE. However, the derivation procedures were time consuming and chemical degradation may occur during the process. Hence, this paper aims to establish a simple solid phase extractionhigh performance liquid chromatography(SPE-HPLC) method to determine the 4-HHE and 4-HNE contents in thermally treated soybean oil. C18 solid phase extraction was applied in the pretreatment process. Firstly, the reliability of the method was evaluated. Good linearity was observed in the range of 0.1–0.5 μg/m L and 0.5–10 μg/m L for 4-HHE and 4-HNE. The limit of detection(LOD) of 4-HHE and 4-HNE were 0.0486 and 0.0129 μg/m L, respectively. And the limit of quantitation(LOQ) of4-HHE and 4-HNE were 0.1458 and 0.0431 μg/m L, respectively. Recovery rate were in the range of89.11%–91.58% and 71.83%–79.40% for 4-HHE and 4-HNE, respectively. The method achieved the extraction, purification and detection of 4-HHE and 4-HNE simultaneously and had the advantages of simple operation, effectiveness, high precision, good repeatability. Then, the method was applied to monitor the concentrations of 4-HHE and 4-HNE in soybean oil heated at 180 °C for 40 h. The contents of 4-HHE and 4-HNE were 0–0.32 μg/g and 0–6.97 μg/g, respectively, which provided guidance for evaluating health risks of thermally treated soybean oil during heating.
基金supported by National Key Technologies R&D Program[grant number 2012BAC19B01]National Key Technologies R&D Program[grant number 2012BAC20B04]+1 种基金National Key Technologies R&D Program[grant number2012BAC09B04]China Clean Development Mechanism Fund[grant number 1113113]
文摘Loss and damage(L&D) from climate change has threatened the sustainable development of humankind,while the progress of mitigative and adaptive measures carried out under the international multilateral framework has been slow.The scientific community and policymakers have placed increasing emphasis on the international L&D response mechanism as a potential direct solution.This paper reviewed the origins of such a mechanism,with an in-depth analysis of the related connotations.A review of the existing situation in China on work related to L&D arising from climate change was conducted,followed by a summary of the findings.Finally,measures and recommendations to improve China's efforts were proposed in this issue.
基金financially supported by the National Natural Science Foundation of China (nos. 31520103911, 31071405, and 31471488)National Basic Research Program of China (no. 2014CB138100)+1 种基金National Key Research and Development Program of China (no. 2016YFD0100102)Genetically Modified Organism Breeding Major Projects (no. 2016ZX08002003)
文摘Gliadins are the major components of storage proteins in wheat and play an important role in determining the extensibility properties of dough.In the present work,six novel full-length γ-gliadin genes were cloned from the C genome of Aegilops markgrafii using a PCR-based strategy.Analysis of the deduced amino acid sequences showed that the cloned genes had primary structures that were similar,but not identical,to published γ-gliadins from other wheat-related species.The lengths of the open reading frames(ORFs)ranged from 909 to 963 bp,and the repetitive and glutamine-rich domains were mainly responsible for the size of the proteins.An extra cysteine residue was present in the repetitive domain of sequence JX566513.All amino acid sequences of γ-gliadin genes from Ae.markgrafii were searched for the five peptides identified as T cell stimulatory epitopes in celiac disease(CD)patients.Peptide Gliγ-3 was present in sequences JX566513 and JX566514.Peptide Gliγ-5 was present only in JX566513.The otherγ-gliadins contained no toxic epitopes.These results provide information to better understand the use of Ae.markgrafii in wheat breeding and the evolutionary relationship of theγ-gliadin genes in Ae.markgrafii and other Triticeae species.
基金supported by the National Natural Science Foundation of China (Grant Nos. 42188101, 42174190, 42025404, and 41904143)the Fundamental Research Funds for the Central Universities (Grant No. 2042021kf0016)+2 种基金the B-type Strategic Priority Program of the Chinese Academy of Sciences (Grant No. XDB41000000)the pre-research projects on Civil Aerospace Technologies funded by the China National Space Administration (Grant Nos. D020308 and D020104)the China Postdoctoral Science Foundation Project (Grant No. 2019M662700)
文摘We report a representative concurrent event of four wave modes at L≈5.0,including electrostatic electron cyclotron harmonic(ECH)waves,exohiss,magnetosonic(MS)waves,and electromagnetic ion cyclotron(EMIC)waves,based on the observations from Van Allen Probe A on October 15,2015.The diffusion coefficients induced by these waves are calculated by using both the Full Diffusion Code and test particle simulations.Moreover,the scattering effects of these waves on energetic electrons are simulated by using a two-dimensional Fokker-Planck diffusion model.The results show that ECH waves mainly scatter low-pitch-angle(<20°)electrons at 0.1-10 keV;exohiss can significantly scatter hundreds of kiloelectron volt electrons to form a reversed energy spectrum;MS waves mainly affect high-pitch-angle electrons(>60°);and EMIC waves scatter only>5 MeV electrons.The combined scattering effects of exohiss and MS waves are stronger than those of exohiss alone.The top-hat pitch angle distributions produced by exohiss are relaxed after adding the effect of MS waves.Because the energies of electrons scattered by ECH waves and EMIC waves are much lower and higher than those scattered by exohiss and MS waves,respectively,the combined scattering effects with the addition of ECH and EMIC waves show little difference from the results for the combination of MS waves and exohiss.These results suggest that distinct wave modes can occur simultaneously and scatter electrons in combination or individually,which requires careful consideration in future global simulations of the complex dynamics of radiation belt energetic electrons.
基金supported by the National Key R&D Program of China(2020YFC0842000)National Natural Science Foundation of China(81960662)Science and Technology Department of Yunnan Province(202001AS070034)。
文摘Severe acute respiratory syndrome coronavirus 2(SARS-Co V-2)is the etiologic agent responsible for the global coronavirus disease 2019(COVID-19)pandemic.Numerous studies have demonstrated that cardiovascular disease may affect COVID-19 progression.In the present study,we investigated the effect of hypertension on viral replication and COVID-19 progression using a hypertensive mouse model infected with SARS-Co V-2.Results revealed that SARS-Co V-2 replication was delayed in hypertensive mouse lungs.In contrast,SARS-Co V-2 replication in hypertensive mice treated with the antihypertensive drug captopril demonstrated similar virus replication as SARS-Co V-2-infected normotensive mice.
基金supported by the National Natural Science Foundation of China (grants 42025404, 42188101, 41904144, and 41674163)the preresearch projects on Civil Aerospace Technologies (grants D020303, D020104, and D020308)+2 种基金funded by the China National Space Administrationthe B-type Strategic Priority Program of the Chinese Academy of Sciences (grant XDB41000000)the Fundamental Research Funds for the Central Universities (grants 2042021kf1045 and 2042021kf1056)
文摘Tailward ion outflows in the Martian-induced magnetotail are known to be one of the major channels for Martian atmospheric escape.On the basis of nearly 6.5 years of observations from the Mars Atmosphere and Volatile EvolutioN(MAVEN)mission,we investigate the statistical distribution of tailward and Marsward fluxes of heavy ions(i.e.,O^(+),and O_(2)^(+))in the near-Mars magnetotail and explore their characteristic responses to the corotating interaction region(CIR),solar wind dynamic pressure,and local magnetic field intensity.Our results show that the tailward fluxes of oxygen ions and molecular oxygen ions in the magnetotail are significantly greater than their Marsward fluxes and that the tailward flux of molecular oxygen ions is generally larger than that of oxygen ions.Furthermore,the tailward ion flux distribution exhibits dependence on the CIR,solar wind dynamic pressure,and local magnetic field strength in a manner stronger than the Marsward ion flux distribution.According to the distribution of tailward ion fluxes,we calculate the corresponding escape rates of heavy ions and show that when the CIR occurs,the total escape rates of oxygen ions and molecular oxygen ions increase by a factor of~2 and~1.2,respectively.We also find that the escape rates of heavy ions increase with the enhancement of solar wind dynamic pressure,whereas the overall effect of the local magnetic field is relatively weak.Our study has important implications for improved understanding of the underlying mechanisms responsible for the Martian atmospheric escape and the evolution of the Martian atmospheric climate.
文摘The finite element method has been increasingly adopted to study the biomechanical behavior of biologic structures. Once the finite element mesh has been generated from CT data set, the assignment of bone tissue’s material properties to each element is a fundamental step in the generation of individualized or subject-specific finite element models. The aim of this work is to simulate the inhomogeneous and anisotropic material properties of femur using the finite element method. A program is developed to read a CT data set as well as the finite element mesh generated from it, and to assign to each element of the mesh the material properties derived from the bone tissue density at the element location. Moreover, for cancellous bone in femoral neck and cortical bone in femoral stem, the principal orientations of transverse isotropy were defined based on the tra-becular structures and the haversian system respectively.
文摘By temperature normalization of the concept of equivalent damage stress proposed by Lemaitre, a new concept of relative damage stress has been put forward as the dominant mechanical factor for the failure of soldered joints under temperature cycling. Finite element numerical simulation results showed that the highest value of relative damage stress occurred at the high temperature hold time during temperature cycling history.
基金supported by National Natural Science Foundation of China(Nos.51827901 and 52225403)the Shenzhen National Science Fund for Distinguished Young Scholars(RCJC20210706091948015).
文摘To systematically validate and calibrate the theory and technology of the deep in-situ conditionpreserved coring, the in-situ conditions at different depths should be simulated, and the full-size coring tests should be carried out in this simulated environment. Therefore, a deep-rock in-situ conditionpreserved coring calibration platform was designed and developed. The self-tightening sealing structure and the quick-disassembly structure were designed on the basis of an innovative segmented nonuniformdiameter structure, which was a breakthrough from the traditional high-pressure vessel frame and was verified by finite element simulation and actual testing under extreme working conditions, respectively.To simulate the actual deep in-situ environment with a temperature of 150℃ and pressure of 140 MPa for a large Φ450 mm×H1400 mm core, temperature and pressure control systems were designed by coupling, and a pre-embedded high-pressure-resistant temperature sensor was designed. Finally, highprecision assembly automation, complex movement coordination of the coring device with the platform,and rotary dynamic sealing were achieved by utilizing the combination of adaptive cabin body servo control and an adaptive mechanical structure in a limited space, laying a solid foundation for the calibration of in-situ condition-preserved coring.
基金supported by National Key R&D Program of China(2018YFC1604205)the National Natural Science Foundation of China(31760431)State Key Laboratory of Food Science and Technology,Nanchang University(SKLF-ZZA-201912)。
文摘Milk allergy is a common allergic reaction found in infants and young children,most of them appear tolerance after growing up.In this study,infant formula was digested by simulated in vitro digestion method.The potential non-allergenic peptides were further screened from undigested products by exclusion of the known epitopes fromβ-lactoglobulin(BLG)andα-lactalbumin(ALA).These potential non-allergenic peptides were synthesized and their transferability were determined by Caco-2 cell monolayer model.Finally,the potential allergenicity were evaluated by KU812 cell degranulation model.The results showed that 7 peptides were screened as non-allergenic sequences,among which were 3 from ALA and 4 from BLG.The Caco-2 cell model showed that all the synthetic peptides were absorbed and transported well.However,only peptide BLG_(107-118)showed potential allegencity by KU812 model.In conclusion,6 peptides,including ALA_(29-51),ALA_(80-90),ALA_(94-103),BLG_(1-20),BLG_(24-50),and BLG_(123-139)were evaluated as hypoallergenic peptides,which could be used for candidates of peptides inducing immune tolerance for persons with milk allergy.
