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Forced motions around triangular libration points by solar radiation pressure in a binary asteroid system

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Astrodynamics 2020年第1期4卷 17-30页

作者： Xi-Yun Hou Xiao-sheng Xin Jing-lang Feng School of Astronomy and Space Science Nanjing University163 Xianlin Ave.Qixia DistrictNanjing210023China Institute of Space Environment and Astrodynamics Nanjing University5 Xanxiu CunGulou DistrictNanjing210093China Key Laboratory of Modern Astronomy and Astrophysics Ministry of EducuationNanjing210023China Beijing Institute of Tracking and Telecommunication Technology 26 Beiqing RoadHaidian DistrictBeijing100094China

By using two tri-axial ellipsoids to approximate the two asteroids,forced orbits around triangular libration points of the binary asteroid system(BAS)induced by solar radiation pressure are *** work is firstly carried out in the doubly synchronous binary asteroid system(DSBAS).The results show that the amplitude of the forced periodic orbit can be large,even for small to moderate surface area-to-mass ratios of the *** position,amplitude,and stability of these forced periodic orbits are influenced by the asteroids'non-spherical ***,the stability of them may be different,depending on the Sun's motion direction *** the BAS's orbit motion *** study is then generalized to the asynchronous and synchronous BAS(ABAS and SBAS,respectively).The forced orbits in the complete system are quasi-periodic orbits around the forced periodic orbit of the averaged system.

关键词： binary asteroid system(BAS) solar radiation pressure forced periodic orbit stability

Numerical simulation of seismic damage and cracking of concrete slabs of high concrete face rockfill dams

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Water Science and Engineering 2016年第3期9卷 205-211页

作者： Wei-jun Cen lang-sheng Wen Zi-qi Zhang Kun Xiong College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China Key Laboratory of Failure Mechanism and Safety Control Techniques of Earth-rock Dam of the Ministry of Water Resources Nanjing 210024 China Changjiang Institute of Survey Planning Design and Research Wuhan 430010 China

Based on the damage constitutive model for concrete, the Weibull distribution function was used to characterize the random distribution of the mechanical properties of materials by finely subdividing concrete slab elements, and a concrete random mesoscopic damage model was established. The seismic response of a 100-m high concrete face rockfill dam(CFRD), subjected to ground motion with different intensities, was simulated with the three-dimensional finite element method(FEM), with emphasis on exploration of damage and the cracking process of concrete slabs during earthquakes as well as analysis of dynamic damage and cracking characteristics during strong earthquakes. The calculated results show that the number of damaged and cracking elements on concrete slabs grows with the duration of earthquakes. With increasing earthquake intensity, the damaged zone and cracking zone on concrete slabs grow wider. During a 7.0-magnitude earthquake, the stress level of concrete slabs is low for the CFRD, and there is almost no damage or slight damage to the slabs. While during a 9.0-magnitude strong earthquake, the percentages of damaged elements and macrocracking elements continuously ascend with the duration of the earthquake, peaking at approximately 26% and 5% at the end of the earthquake, respectively. The concrete random mesoscopic damage model can depict the entire process of sprouting, growing, connecting, and expanding of cracks on a concrete slab during earthquakes.

关键词： Concrete face rockfill dam Random mesoscopic damage model Seismic response Dynamic damage to concrete slab Macrocracking Numerical simulation

Rapid Inactivation of Chloroplastic Ascorbate Peroxidase is Responsible for Oxidative Modification to Rubisco in Tomato (Lycopersicon esculentum) under Cadmium Stress

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Journal of Integrative Plant Biology 2008年第4期50卷 415-426页

作者： Kai-lang Liu Lin Shen Jia-Qi Wang Ji-Ping sheng College of Food Science and Nutritional Engineering China Agricultural University Beijing 100083 China State Key Laboratory of Animal Nutrition Institute of Animal Science Chinese Academy of Agricultural Sciences Beijing 100094 China

To investigate the sensitive site of antioxidant systems in chloroplast under cadmium stress and its consequence on reactive oxygen species production and action, the sub-organellar localization of chloroplast superoxide dismutases （SOD, EC 1.***.1.1） and ascorbic peroxidase （APX, EC 1.***.1.11） isoenzymes and changes of enzymes activities under cadmium stress were investigated in tomato seedlings. Two APX isoforms, one thylakoid-bound and one stromal, were detected. Cd at 50 μM induced a moderate increase of SOD activities but a rapid inactivation of both APX isoenzymes. APX inactivation was mainly related to the decrease of ascorbate concentration, as supported by in vitro treatment of exogenous ascorbate and APX kinetic properties under Cd stress. H2O2 accumulation in chloroplast, as a consequence of APX inactivation, was associated with a 60% loss of Rubisco （EC 4.***.1.39） activity, which could be partially accounted for by a 10% loss of Rubisco content. Protein oxidation assay found that the Rubisco large subunit was the most prominent carbonylated protein; the level of carbonylated Rubisco large subunit increased fivefold after Cd exposure. Thiol groups in the Rubisco large subunit were oxidized, as indicated by non-reducing electrophoresis. Treating crude extract with H2O2 resulted in a similar pattern of protein oxidation and thiols oxidation with that observed in Cd-treated plants. Our study indicates that APXs in the chloroplast is a highly sensitive site of antioxidant systems under Cd stress, and the inactivation of APX could be mainly responsible for oxidative modification to Rubisco and subsequent decrease in its activity.

关键词： ascorbate peroxidase cadmium hydrogen peroxide protein oxidation Rubisco.

Non-Hermitian topological Anderson insulators

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Science China(Physics,Mechanics & Astronomy) 2020年第6期63卷 2-12页

作者： Dan-Wei Zhang ling-Zhi Tang Li-Jun lang Hui Yan Shi-Liang Zhu Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials GPETR Center for Quantum Precision Measurement and SPTESouth China Normal UniversityGuangzhou 510006China National Laboratory of Solid State Microstructures School of PhysicsNanjing UniversityNanjing 210093China

Non-Hermitian systems can exhibit exotic topological and localization *** we elucidate the non-Hermitian effects on disordered topological systems using a nonreciprocal disordered Su-Schrieffer-Heeger *** show that the non-Hermiticity can enhance the topological phase against disorders by increasing bulk ***,we uncover a topological phase which emerges under both moderate non-Hermiticity and disorders,and is characterized by localized insulating bulk states with a disorder-averaged winding number and zero-energy edge *** topological phases induced by the combination of non-Hermiticity and disorders are dubbed non-Hermitian topological Anderson *** reveal that the system has unique non-monotonous localization behavior and the topological transition is accompanied by an Anderson *** properties are general in other non-Hermitian models.

关键词： topological insulators non-Hermitian systems localization properties

Advances in porous volumetric solar receivers and enhancement of volumetric absorption

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Energy Reviews 2023年第3期2卷 23-44页

作者： Ya-ling He Shen Du sheng Shen Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education School of Energy and Power EngineeringXi'an Jiaotong UniversityXi'anShaanxi710049China Department of Mechanical Engineering Carnegie Mellon UniversityPittsburghPA15213USA

Porous volumetric solar receivers are one type of solar receivers that can volumetrically absorb solar radiation and achieve efficient solar-to-thermal energy *** volumetric solar receivers have been developed since *** this review,we focus on the development progress of the atmospheric and pressurized porous volumetric solar receivers,in which the structural designs,the material selections,the experimental research methods,the comparison of thermal performance,and the transient response characteristic of the receivers were *** the other hand,the theoretical research methods including the direct pore-scale and volume averaging simulations were *** pore-scale reconstruction method and the procedure to investigate the fluid flow and heat transfer processes at the pore-scale were *** the volume averaging method,detailed descriptions for the selection of empirical parameters in the governing equations to be solved were *** research results based on these methods were presented and research limitations were also pointed ***,the methods for the enhancement of volumetric absorption and the improvement of thermal efficiency of the receivers have been comprehensively *** methods including geometrical parameters optimization and spectrally selective absorption were presented in *** review will provide a better understanding of the development and research methods for porous volumetric solar receivers,and inspire future studies for the performance improvement of the receivers.

关键词： Porous media Volumetric solar receiver Experiment progress Direct pore-scale simulation Volume averaging simulation Volumetric absorption enhancement

Tribological behavior of a Ni-WS2 composite coating across wide temperature ranges

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Rare Metals 2019年第11期38卷 1078-1085页

作者： Shuai Cui Wen-sheng Li ling He Li Feng Guo-sheng An Wei Hu Chun-Xia Hu School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou 730050China

In order to reduce the friction coefficient of a pure nickel coating and extend the lifetime of metal parts under extreme friction conditions,a series of Ni-based WS2-composite solid lubrication coating containing different WS2 concentrations were prepared on a 45#mild carbon steel substrate by *** cyclic voltammetry method was used to investigate the electroplating regulation of the Ni-WS2 composite coatings.X-ray diffraction(XRD) and scanning electron microscopy(SEM) were used to analyze the microstructures and wear surfaces of the composite coatings,the tribological properties and wear mechanisms of the composite coatings with different WS2 *** results show that the addition of WS2 can promote the cathode polarization of the electroplating process,and the polarization degree goes up with the increase in WS2 *** friction coefficient of Ni-composite coatings significantly decreases by the addition of WS2 *** lowest friction coefficient at room temperature is obtained at a value around 0.01-0.03 from the coating deposited in the electrolyte solution with a 30g·L^-1 WS2 *** friction coefficient of the Ni-WS2 composite coating remains in 0.01-0.03 with the increase in temperature from room temperature to 300℃.When the temperature goes up to 500℃,the friction coefficient manifests a continuous increase to 0.12,because WS2 is gradually oxidized into WO3 and therefore loses its lubrication ability.

关键词： WS2 Self-lubricating composites coating Frictional wear Temperature

Template-directed synthesis of pyridazine-containing tetracationic cyclophane for construction of[2]rotaxane

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Chinese Chemical Letters 2017年第5期28卷 1013-1017页

作者： Qiu-sheng Fang ling Chen Qing-Yan Liu Department College of Chemistry and Chemical Engineering Key Laboratory of Functional Small Organic MoleculesMinistry of EducationInstitution Jiangxi Normal UniversityNanchang 330022China

Benefiting from its bent molecular structure,3,6-pyridazinyl contained tetracationic cyclophane（1） is synthesized by template-directed method with high isolated yield up to 92%.This template-directed strategy is fur... 详细信息

关键词： Tetracationic cyclophane Template effect Inclusion complex π-Stacking Rotaxane

Mimetic Preparation of Analogues of Territrem B, A Potent Acetylcholinesterase Inhibitor

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Chinese Chemical Letters 2000年第12期11卷 1045-1048页

作者： Yu ZHAO Yuan ling KU Shoei sheng LEE Laboratory of Phytochemistry Kunming Institute of BotanyChinese Academy of SciencesKunming 650204 School of Pharmacy College of MedicineNational Taiwan UniversityTaipei 10018

A mimetic synthesis of a potent acetylcholinesterase inhibitor, Territrem B, was carried out from the naturally occurring jujubosides. The anti-AChE activity of the product, which possesses the 2-en-1-one pharmacophore and the aromatic ring, was measured. The aromatic ring moiety seemed to be less influencing when comparing with the 2-en-1-one moiety.

关键词： acetylcholinesterase inhibitor territrem B analogues jujubosides

Entanglement of a Five-Qubit Heisenberg XX Chain in a Magnetic Field

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Communications in Theoretical Physics 2009年第5期51卷 811-814页

作者： CAO Min ling Yin-sheng ZHU Shi-Qun School of Science Nantong University Nantong 226007 China School of Physical Science and Technology Suzhou University Suzhou 215006 China

We calculate the eigenvalues and eigenvectors of a five-qubit isotropic Heisenberg model in an external magnetic field, and give analytical results for the concurrence of two nearest-neighbor qubits. A magnetic field can eliminate degeneration and change the ground state of the system. Therefore increasing the value of the magnetic field can induce entanglement in a certain range both for the antiferromagnetic and ferromagnetic case.

关键词： entanglement five-qubit Heisenberg chain