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Dynamic model and performance analysis of landing buffer for bionic locust mechanism

Acta Mechanica Sinica 2016年第3期32卷 551-565页

作者： Dian-Sheng Chen zi-Qiang Zhang Ke-wei Chen Robotic Institute Beihang University

The landing buffer is an important problem in the research on bionic locust jumping robots, and the different modes of landing and buffering can affect the dynamic performance of the buffering process significantly. Based on an experimental observation, the different modes of landing and buffering are determined, which include the different numbers of landing legs and different motion modes of legs in the buffering process. Then a bionic locust mechanism is established, and the springs are used to replace the leg muscles to achieve a buffering effect. To reveal the dynamic performance in the buffering process of the bionic locust mechanism, a dynamic model is established with different modes of landing and buffering. In particular, to analyze the buffering process conveniently, an equivalent vibration dynamic model of the bionic locust mechanism is *** the support forces of the ground to the leg links, which can be obtained from the dynamic model, the spring forces of the legs and the impact resistance of each leg are the important parameters affecting buffering performance, and evaluation principles for buffering performance are proposed according to the aforementioned parameters. Based on the dynamic model and these evaluation principles, the buffering performances are analyzed and compared in different modes of landing and buffering on a horizontal plane and an inclined plane. The results show that the mechanism with the ends of the legs sliding can obtain a better dynamic performance. This study offers primary theories for buffering dynamics and an evaluation of landing buffer performance,and it establishes a theoretical basis for studies and engineering applications.

关键词： Bionic locust mechanism Landing and buffering Dynamic model Buffering performance

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On Ramanujan Sums over a Dedekind Domain with Finite Norm Property

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Acta Mathematica Sinica,English Series 2023年第1期39卷 149-160页

作者： Zhi Yong ZHENG Man CHEN zi wei HONG School of Mathematics Renmin University of ChinaBeijing 100872P.R.China School of Mathematical Sciences Beihang UniversityBeijing 100191P.R.China

In this paper,we consider Ramanujan’s sums over arbitrary Dedekind domain with finite norm *** define the Ramanujan’s sumsη(a,A)andη(B,A),where a is an arbitrary element in a Dedekind domain,B is an ideal and A is a non-zero *** particular,we discuss the Kluyver formula and Hèolder formula forη(a,A)andη(B,A).We also prove the reciprocity formula enjoyed byη(B,A)and the orthogonality relations forη(a,A)in the last two parts.

关键词： Dedekind domains Ramanujan Sums primitive additive character reciprocity formula orthogonality property

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On the uniqueness of Einstein-Cartan theory:Lagrangian,covariant derivative and equation of motion

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Communications in Theoretical Physics 2023年第4期75卷 63-69页

作者： zi-wei Chen Run Diao Xiang-Song Chen School of Physics Huazhong University of Science and TechnologyWuhan 430074China

In the standard Einstein-Cartan theory,matter fields couple to gravity through the Minimal Coupling Procedure(MCP),and yet leave the theory an *** MCP to the action or to the equation of motion would lead to different gravitational *** propose a new covariant derivative to remove the ambiguity and discuss the relation between our proposal and previous treatments on this subject.

关键词： Lagrangian covariant derivative equation of motion uniqueness

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A blockchain-based transaction system for private data sharing and trading

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Control Theory and Technology 2022年第3期20卷 291-302页

作者： wei cui Yu Pan Zhendong Ai School of Automation Science and Engineering South China University of TechnologyGuangzhou510640GuangdongChina College of Control Science and Engineering Zhejiang UniversityHangzhou310058ZhejiangChina

To address the private data management problems and realize privacy-preserving data sharing,a blockchain-based transaction system named Ecare featuring information transparency,fairness and scalability is *** proposed system formulates multiple private data access control strategies,and realizes data trading and sharing through on-chain transactions,which makes transaction records transparent and *** our system,the private data are encrypted,and the role-based account model ensures that access to the data requires owner’s ***,a new consensus protocol named Proof of Transactions(PoT)proposed by ourselves has been used to improve consensus *** value of Ecare is not only that it aggregates telemedicine,data transactions,and other features,but also that it translates these actions into transaction events stored in the blockchain,making them transparent and immutable to all *** proposed system can be extended to more general big data privacy protection and data transaction scenarios.

关键词： Private data sharing Blockchain Data access control Proof of Transactions

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Impurity effects of theΛhyperon in the hypernuclear systems^(25)ΛMg and(29)ΛSi

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Communications in Theoretical Physics 2021年第11期73卷 116-121页

作者： Ji-wei cui Xian-Rong Zhou School of Physics and Optoelectronic Engineering Xidian UniversityXi'an 710071China Department of Physics East China Normal UniversityShanghai 200241China

Based on the beyond-mean-field Skyrme-Hartree-Fock model,impurity effects of theΛhyperon in the hypernuclear systems^(25)ΛMg and^(29)ΛSi are investigated,*** cases,in which theΛhyperon occupies the single-particle orbitals L[000]1+/2,L[110]1-/2,L[101]3-/2 and L[101]1-/2,are *** each case,the potential energy surface and the energy curves projected on certain angular momenta are employed to show the influence of theΛhyperon on the nuclear *** the shrinkage effect that is induced by theΛhyperon occupying the sΛorbital,it is found that theΛhyperon on the pΛorbital,L[110]1-/2,drives the nuclear core toward a prolate shape,while the ones on the other two pΛorbitals,L[101]3-/2 and L[101]1-/2,drive the nuclear core toward an oblate *** energy spectra and the corresponding intra-band E2 transition rates for the rotational bands are given as a prediction for future experiments.

关键词： Λhypernuclei Skyrme-Hartree-Fock model angular momentum projection generator coordinate method

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Effects of thrombopoietin pre-treatment on peri-liver transplantation thrombocytopenia in a mouse model of cirrhosis with hypersplenism

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World Journal of Gastrointestinal Surgery 2023年第10期15卷 2115-2122页

作者： zi-Rong Liu Ya-Min Zhang zi-Lin cui Wen Tong Department of Hepatobiliary Surgery Tianjin First Central HospitalTianjin 300070China

BACKGROUND During cirrhosis,the liver is impaired and unable to synthesize and clear thrombopoietin *** the same time,the spleen assumes the function of hemofiltration and storage due to liver dysfunction,resulting in hypersplenism and excessive removal of platelets in the spleen,further reducing platelet *** liver function is decompensated in cirrhotic patients,the decrease of thrombopoietin(TPO)synthesis is the main reason for the decrease of new platelet *** change of TPO leads to thrombocytopenia and bleeding tendency in cirrhotic patients with *** To investigate the clinical efficacy of recombinant human TPO(rhTPO)in the treatment of perioperative thrombocytopenia during liver transplantation in cirrhotic mice with *** C57BL/6J mice and TPO receptor-deficient mice were used to establish models of cirrhosis with ***,these mice underwent orthotopic liver transplantation(OLT).The mice in the experimental group were given rhTPO treatment for 3 consecutive days before surgery and 5 consecutive days after surgery,while the mice in the control group received the same dose of saline at the same *** in liver function and platelet counts were determined between the experimental and control ***-linked immunosorbent assay was used to assess the expression of TPO and TPO receptor(c-Mpl)in the *** Preoperative administration of rhTPO significantly improved peri-OLT thrombocytopenia in mice with cirrhosis and *** the expression of TPO receptors exacerbated peri-OLT *** concentration of TPO decreased while the concentration of c-Mpl increased in compensation in the mouse model of cirrhosis with *** pre-treatment significantly increased the postoperative TPO concentration in mice,which in turn led to a decrease in the c-Mpl *** pre-treatment also significantly enhanced the Janus kinase(Jak)/signal

关键词： Thrombopoietin pre-treatment Cirrhosis Liver transplantation Perioperative period Platelet

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Electrochemical synthesis,structure characterization and magnetic properties of Tb_(x)Fe_(7)Co_(3)(x=0,0.6,0.8) nanowires

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Journal of Rare Earths 2021年第5期39卷 565-571页

作者： Licong Kang Chunxiang cui Yuanyuan Zhang wei Yang Qiong Li Sen cui Key Lab.for New Type of Functional Material in Hebei Province School of Materials Science and EngineeringHebei University of TechnologyTianjin 300130China Department of Macromolecular Science and Engineering Case Western Reserve UniversityClevelandOH44106United States

Highly ordered Tb_(x)Fe_(7)Co_(3)(x=0,0.6,0.8)nanowires were synthesized in alumina templates by electrochemical deposition ***,the effects of Tb content and annealing treatment on the phase composition,morphology,crystalline structure and magnetic properties were *** asdeposited Tb_0 Fe_(7)Co_(3)nanowires comprise Fe_(7)Co_(3)*** after adding Tb,the diffraction peaks slightly shift left,indicating the infiltration of Tb atoms into Fe_(7)Co_(3)*** annealing,Tb_0 Fe_(7)Co_(3)nanowires still consist of Fe_(7)Co_(3)phase with a slight enhancement on *** the annealed nanowires with Tb doped present a complex phase composition containing Fe3 Tb,Fe_(2)Tb,Co_(3)Tb,Co_(17)Tb_(2),TbFeO_(3)and Fe_(2)O_(3)phases distribute in the central portion,and Co_(0.72)Fe_(0.28)at the nanowire outer *** annealed Tb_(x)Fe_(7)Co_(3)(x=0.6,0.8)nanowires show higher magnetic performance owing to the formation of hard magnetic phases,the interfacial elastic coupling between hard and soft phases and the coherent Fe3 Tb/Co_(3)Tb interface which restrain the domain wall *** be specific,the coercivity and remanence ratio of TbxFe_(7)Co_(3)(x=0.6,0.8)nanowires significantly enhance with increasing Tb content.

关键词： Tb-Fe-Co nanowires Electrodeposition Crystal structure Magnetic properties Coercivity mechanism Rare earths

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A constrained particle dynamics for continuum-particle hybrid method in micro- and nano-fluidics

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Acta Mechanica Sinica 2006年第6期22卷 503-508页

作者： Jia cui Guo wei He Dewei Qi LNM Institute of Mechanics Chinese Academy of SciencesBeijing 100080 China Department of Paper and Chemical Engineering Western Michigan University Kalamazoo MI 49008 USA

A hybrid method of continuum and particle dynamics is developed for micro- and nano-fluidics, where fluids are described by a molecular dynamics （MD） in one domain and by the Navier-Stokes （NS） equations in another domain. In order to ensure the continuity of momentum flux, the continuum and molecular dynamics in the overlap domain are coupled through a constrained particle dynamics. The constrained particle dynamics is constructed with a virtual damping force and a virtual added mass force. The sudden-start Couette flows with either non-slip or slip boundary condition are used to test the hybrid method. It is shown that the results obtained are quantitatively in agreement with the analytical solutions under the non-slip boundary conditions and the full MD simulations under the slip bound- ary conditions.

关键词： Hybrid method Molecular dynamicsimulation Navier-Stokes equation Microfluidics

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Rational design and energy catalytic application of high-loading single-atom catalysts

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Rare Metals 2024年第10期43卷 4844-4866页

作者： zi-wei Deng Yue Liu Jie Lin Wen-Xing Chen Energy and Catalysis Center School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Ningbo Institute of Materials Technology and Engineering Chinese Academy of ScienceNingbo 315201China

It is well known that single-atom catalysts(SACs)have become a hot topic in the field of catalysis due to their advantages such as 100%metal atom utilization efficiency,high catalytic activity and selectivity compared with conventional catalysts and ***,the isolated metal atoms on SACs have thermodynamic instability and tend to agglomerate,which limit their catalytic ***,it is of great significance to synthesize stable and high-loading single-atom catalysts(HLSACs).In this paper,we review the research progress of HLSACs from two aspects:design and ***,we comprehensively introduce the synthesis strategies of HLSACs,namely,top-down and bottom-up ***,we overview the application status of HLSACs in three fields:electrocatalysis,thermal catalysis and ***,we summarize the development prospects and challenges of HLSACs.

关键词： High-loading single-atom catalysts Design Electrocatalysis Thermal catalysis Photocatalysis

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Cloning and Expression of Rat Liver S-Adenosylmethionine Synthetase

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Chemical Research in Chinese Universities 2006年第2期22卷 236-238页

作者： cui wei HUANG Lei LI wei WANG Li-ping College of Life Science Jilin University Changchun 130021 P. R. China

The S-adenosylmethionine synthetase（SAM synthetase） is responsible for in vivo synthesis of S-adenosylmethionine（SAM）, which is a kind of biologically active molecules distributed in all body tissues and fluids and involved in a number of biochemical reactions. In this study, a cDNA containing the coding sequence for rat liver SAM synthetase was cloned into the prokaryotic expression vector pQE30 and expressed in E. coli M15. A major band corresponding to a protein of 48 kDa was detected on SDS-PAGE. The protein was distributed in both the soluble fraction and the insoluble fraction. In soluble fractions the protein was fully active.

关键词： SAM SAM synthetase, Cloning Expression HPLC

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