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Analytical libration control law for electrodynamic tether system with current constraint

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Astrodynamics 2024年第2期8卷 237-246页

作者： Shidong Xu ti chen Hao Wen Dongping Jin State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China

This study focuses on stabilizing the libration dynamics of an electrodynamic tether system(EDTS)using generalized torques induced by the Lorentz *** contrast to existing numerical optimization methods,a novel analytical feedback control law is developed to stabilize the in-plane and out-of-plane motions of a tether by modulating the electric current *** saturation constraint on the current is accounted for by adding an auxiliary dynamic system to the *** enhance the robustness of the proposed controller,multiple perturbations of the orbital dynamics,modeling uncertainties,and external disturbances are approximated using a neural network in which the weighting matrix and approximation error are estimated simultaneously,such that these perturbations are well compensated for during the control design of the ***,a dynamically scaled generalized inverse is utilized to address the singular matrix in the control *** closed-loop system is proven to be ultimately bounded based on Lyapunov stability ***,numerical simulations are performed to demonstrate the effectiveness of the proposed analytical control law.

关键词： electrodynamic tether system(EDTS) libration dynamics analytical control current constraint

Studies on NaXe Clusters

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Chinese Chemical Letters 2001年第9期12卷 833-834页

作者： Jia Chang LIANG Zhi LIU Yi Min SHEN Xian Ping SUN Xi Zi ZENG Xiao Yun LE Xiang Yun WANG De Min WANG Fu Chun YU yong ti chen College of sciences Civil Aviation Institute of ChinaTianjin 300300 Department of Chemistry Nankai UniversityTianjin 300071 Department of Radiology Wayne State UniversityDetroit MI 48201 USA Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Phys.&Math.The Chincse Academy of SciencesWuhan 430071 Institute of Heavy lon Physics Peking UniversityBeijing 100871

The chemical shift of Na-23 in excimer NaXe was measured by using nuclear magnetic resonance (NMR) spectra, which is in good agreement with the theoretical value obtained by ab initio calculations. The bond length, dissociation energy, dipole of NaXe and Mulliken charges at Na and Xe in NaXe were calculated, respectively. The spectra of ultraviolet (UV) fluorescence and surface-enhanced Raman scattering of NaXe were also measured.

关键词： Xenon-ion-implanted NaCl crystal NaXe chemical shift ab initio calculation

Surviving winter on the Qinghai-Xizang Plateau:Extensive reversible protein phosphorylation plays a dominant role in regulating hypometabolism in hibernating Nanorana parkeri

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Zoological Research 2024年第1期45卷 1-12页

作者： yong-Gang Niu Deng-Bang Wei Xue-Jing Zhang ti-Sen Xu Xiang-yong Li Hai-Ying Zhang Zhi-Fang An Kenneth B.Storey Qiang chen Department of Life Sciences Dezhou UniversityDezhouShandong 253023China State Key Laboratory of Plateau Ecology and Agriculture Qinghai UniversityXiningQinghai 810016China School of Life Sciences Lanzhou UniversityLanzhouGansu 730000China Department of Biology Carleton UniversityOttawaON K1S 5B6Canada

Changes in protein abundance and reversible protein phosphorylation(RPP)play important roles in regulating hypometabolism but have never been documented in overwintering frogs at high *** test the hypothesis that protein abundance and phosphorylation change in response to winter hibernation,we conducted a comprehensive and quantitative proteomic and phosphoproteomic analysis of the liver of the Xizang plateau frog,Nanorana parkeri,living on the Qinghai-Xizang *** total,5170 proteins and 5695 phosphorylation sites in 1938 proteins were *** on proteomic analysis,674 differentially expressed proteins(438 up-regulated,236 down-regulated)were screened in hibernating *** versus summer *** enrichment analysis revealed that higher expressed proteins in winter were significantly enriched in immune-related signaling pathways,whereas lower expressed proteins were mainly involved in metabolic processes.A total of 4251 modified sites(4147 up-regulated,104 down-regulated)belonging to 1638 phosphoproteins(1555 up-regulated,83 down-regulated)were significantly changed in the *** hibernation,RPP regulated a diverse array of proteins involved in multiple functions,including metabolic enzymatic activity,ion transport,protein turnover,signal transduction,and alternative *** changes contribute to enhancing protection,suppressing energy-consuming processes,and inducing metabolic ***,the activities of phosphofructokinase,glutamate dehydrogenase,and ATPase were all significantly lower in winter compared to *** conclusion,our results support the hypothesis and demonstrate the importance of RPP as a regulatory mechanism when animals transition into a hypometabolic state.

关键词： Nanorana parkeri Proteomic Phosphoproteomic Hibernation Reversible protein phosphorylation Metabolism

Research on the influences of motion characteristics of jetting projectile charge under water

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Defence Technology（防务技术） 2024年第3期33卷 411-425页

作者： Xing chen yong-gang Lu Institute of Systems Engineering China Academy of Engineering PhysicsMianyang 621900SichuanChina

Shaped charge warhead is important for enhancing the damage performance of underwater *** paper used finite element analysis software and based on JPC water penetration experiments to examine the influence of liner parameters(wall thickness,material),charge aspect ratio,and stand-off distance on the movement characteristics of JPC in *** findings reveal that the head diameter of the JPC increases and experiences significant erosion after entering the water,the effective length of the JPC in water undergoes two distinct phases:a growth phase and a decrease phase,with the velocity of the JPC decaying *** the liner thickness,stand-off distance and the charge aspect ratio can improve the erosion resistance and the velocity retention capacity of the *** optimal ranges for liner thickness and stand-off distance are 0.0363D_(k) to 0.0545D_(k)(D_(k) is the charge diameter),the stand-off distance should be within 1.0D_(k).After the charge aspect ratio higher than 1.25,the charge structure exerts minimal influence the movement characteristics of the JPC in *** density plays a crucial role in the velocity decay pattern of the JPC during *** with higher densities exhibit superior velocity retention capabilities in water,with the velocity decay pattern converging if the densities are ***,copper,tantalum and tungsten liners are deemed appropriate for underwater shaped charge ***,the results will provide an important reference for the design of underwater shaped charge warhead.

关键词： JPC Movement characteristics Underwater penetration Numerical simulation

Physics-Informed Neural Networks with Two Weighted Loss Function Methods for Interactions of Two-Dimensional Oceanic Internal Solitary Waves

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Journal of Systems Science & Complexity 2024年第2期37卷 545-566页

作者： SUN Junchao chen yong TANG Xiaoyan School of Mathematical Sciences Key Laboratory of Mathematics and Engineering Applications(Ministry of Education)&Shanghai Key Laboratory of PMMPEast China Normal UniversityShanghai 200241China College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

The multiple patterns of internal solitary wave interactions(ISWI)are a complex oceanic *** remote sensing techniques indirectly detect these ISWI,but do not provide information on their detailed structure and ***,the authors considered a three-layer fluid with shear flow and developed a(2+1)Kadomtsev-Petviashvili(KP)model that is capable of describing five types of oceanic ISWI,including O-type,P-type,TO-type,TP-type,and *** learning models,particularly physics-informed neural networks(PINN),are widely used in the field of fluids and internal solitary ***,the authors find that the amplitude of internal solitary waves is much smaller than the wavelength and the ISWI occur at relatively large spatial scales,and these characteristics lead to an imbalance in the loss function of the PINN *** solve this problem,the authors introduce two weighted loss function methods,the fixed weighing and the adaptive weighting methods,to improve the PINN *** successfully simulated the detailed structure and dynamics of ISWI,with simulation results corresponding to the satellite *** particular,the adaptive weighting method can automatically update the weights of different terms in the loss function and outperforms the fixed weighting method in terms of generalization ability.

关键词： Internal solitary wave interactions KP equation PINN method weighted loss function method

High-order Soliton Matrix for the Third-order Flow Equation of the Gerdjikov-Ivanov Hierarchy Through the Riemann-Hilbert Method

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 358-378页

作者： Jin-yan ZHU yong chen School of Mathematical Sciences Shanghai Key Laboratory of Pure Mathematics and Mathematical PracticeEast China Normal UniversityShanghai 200062China College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

The Gerdjikov-Ivanov(GI)hierarchy is derived via recursion operator,in this article,we mainly investigate the third-order flow GI *** the framework of the Riemann-Hilbert method,the soliton matrices of the third-order flow GI equation with simple zeros and elementary high-order zeros of Riemann-Hilbert problem are constructed through the standard dressing *** advantage of this result,some properties and asymptotic analysis of single soliton solution and two soliton solution are discussed,and the simple elastic interaction of two soliton are *** with soliton solution of the classical second-order flow,we find that the higher-order dispersion term affects the propagation velocity,propagation direction and amplitude of the ***,by means of a certain limit technique,the high-order soliton solution matrix for the third-order flow GI equation is derived.

关键词： Gerdjikov-Ivanov hierarchy third-order flow GI equation Riemann-Hilbert method high-order soliton

Long-time Asymptotics for the Reverse Space-time Nonlocal Hirota Equation with Decaying Initial Value Problem:without Solitons

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 708-727页

作者： Wei-qi PENG yong chen School of Mathematical Sciences East China Normal UniversityShanghai 200241China College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

In this work,we mainly consider the Cauchy problem for the reverse space-time nonlocal Hirota equation with the initial data rapidly decaying in the solitonless *** from the Lax pair,we first construct the basis Riemann-Hilbert problem for the reverse space-time nonlocal Hirota ***,using the approach of Deift-Zhou nonlinear steepest descent,the explicit long-time asymptotics for the reverse space-time nonlocal Hirota is *** the reverse space-time nonlocal Hirota equation,since the symmetries of its scattering matrix are different with the local Hirota equation,the v(λ_(i))(i=0,1)would like to be imaginary,which results in theδ_(λi)^(0)contains an increasing t(±Imv(λ_(i)))/2,and then the asymptotic behavior for nonlocal Hirota equation becomes differently.

关键词： Riemann-Hilbert problem reverse space-time nonlocal Hirota equation long-time asymptotics nonlinear steepest descent method

The Role of Adipose tissue-derived Exosomes in Chronic Metabolic Disorders

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Current Medical Science 2024年第3期44卷 463-474页

作者： Rui HE yong chen Division of Endocrinology Department of Internal MedicineTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China Laboratory of Endocrinology & Metabolism Key Laboratory of Vascular Aging of the Ministry of EducationTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China Branch of National Clinical Research Center for Metabolic Diseases Wuhan430030China

Excessive fat deposition in obese subjects promotes the occurrence of metabolic diseases,such as type 2 diabetes mellitus(T2DM),cardiovascular diseases,and non-alcoholic fatty liver disease(NAFLD).Adipose tissue is not only the main form of energy storage but also an endocrine organ that not only secretes adipocytokines but also releases many extracellular vesicles(EVs)that play a role in the regulation of whole-body *** are a subtype of EVs,and accumulating evidence indicates that adipose tissue exosomes(AT Exos)mediate crosstalk between adipose tissue and multiple organs by being transferred to targeted cells or tissues through paracrine or endocrine ***,the roles of AT Exos in crosstalk with metabolic organs remain to be fully *** this review,we summarize the latest research progress on the role of AT Exos in the regulation of metabolic ***,we discuss the potential role of AT Exos as biomarkers in metabolic diseases and their clinical application.

关键词： exosome adipose tissue obesity diabetes chronic metabolic disorder miRNA

Low-cycle fatigue behavior of solutionized and aged WE43 magnesium alloys at room temperature

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Journal of Magnesium and Alloys 2024年第6期12卷 2284-2297页

作者： yong Cai Jianxiong Wei Hong Yan Yipeng chen Rongshi chen School of Materials Science and Engineering University of Science and Technology of China72 Wenhua RoadShenyang 110016China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of Materials Science and Engineering Shandong University of Science and TechnologyQingdaoShandong 266590China

The low-cycle fatigue behavior of solutionized(T4)and aged(T6)WE43 magnesium alloys was studied at room *** total strain amplitudes(△ε_(t)/2)were 0.4%,0.5%,0.6%,0.7%and 1.0%.Detailed microstructure evolution was characterized by scanning electron microscope(SEM),electron backscattered diffraction(EBSD)and transmission electron microscopy(TEM).The results showed that plastic strain amplitude decreased with the increasing cycle number in T4 alloy,which is due to the dense persistent slip bands(PSBs)and dynamic precipitates hinderingdislocation *** contrast,the plastic strain amplitude increases gradually in T6 alloy,which is attributed to the enhanced activation of pyramidal *** low-cycle fatigue life of T6 alloy with larger fatigue ductility coefficient is longer than that of T4 *** Coffin-Manson model can accurately predict the fatigue life of T4 and T6 alloys compared to Jahed-Varvani(JV)energy *** T4 alloy,the fatigue damage mechanism was dominated by basal *** T6 alloy,the enhanced pyramidal slip plays an important role to accommodate plastic deformation.

关键词： Low-cycle fatigue WE43 alloy Cyclic hardening/softening JV model Dislocation