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Divergent Pathways and Dynamic Effects of Intramolecular HydrideTransfer Reactions Mediated by Cp^*M(Ⅲ)Complexes(M=Co,Rh,lr)

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Chinese Journal of Chemistry 2020年第12期38卷 1579-1584页

作者： chao zheng State Key Laboratory of Orgonometallic Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of Sciences345 Lingling LuShanghai 200032China

of main observation and conclusion Transition-metal-mediated hydride transfer reactions are fundamental steps in olefin polymerization and isomerization processes.P-Hydride elimination/migratory insertion sequence and ligand-to-ligand hydrogen transfer mechanism have been proposed for these *** have performed comprehensive theoretical studies on prototype 1,4-hydride transfer reactions mediated by the Cp^*M(Ⅲ)complexes(M=Co,Rh,Ir).Depending on the metal center,the reaction courses are quite divergent,ranging from dynamically concerted to explicitly stepwise manner.A More O'Farrell-Jencks-type plot is suggested to demonstrate the perturbation to the mechanistic continuum from the significant dynamic effects.

关键词： hydride steps perturbation

Quantum secure direct dialogue using Einstein-Podolsky-Rosen pairs

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Science China(Physics,Mechanics & Astronomy) 2014年第7期57卷 1238-1243页

作者： zheng chao LONG GuoFei State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua University Tsinghua National Laboratory for Information Science and Technology Department of Physics Shandong University Department of Physics Loughborough University

A two-step quantum secure direct dialogue protocol using Einstein-Podolsky-Rosen(EPR)pair block is *** the protocol,the dialogue messages are encoded on series of qubits and sent through a quantum channel *** security of the protocol is assured by its connection to the two-step quantum secure direct communication protocol,which has been proved *** protocol has several *** is a direct communication protocol that does not require a separate classical communication for the *** has high capacity as two bits of secret messages can be transmitted by an EPR *** a dialogue protocol,the two parties can speak to each other either simultaneously or sequentially.

关键词： quantum communication QSDC QSDD EPR pairs

Post-spin crossing dynamics determine the regioselectivity in open-shell singlet biradical recombination

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Organic Chemistry Frontiers 2022年第4期9卷 995-1003页

作者： Min Zhu chao zheng State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of Sciences345 Lingling LuShanghai 200032China School of Physical Science and Technology ShanghaiTech University100 Haike RoadShanghai 201210China

Radical recombination is among the fastest reactions in organic *** high levels of selectivity in this type of reaction is rather *** a recent report on visible-light-induced dearo-mative cycloaddition of pyrrole-tethered vinylcyclopropanes,extraordinary regioselectivity was observed during the intramolecular open-shell singlet biradical recombination step.

关键词： singlet radical regioselectivity

An Isogeometric Cloth Simulation Based on Fast Projection Method

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Computer Modeling in Engineering & Sciences 2023年第3期134卷 1837-1853页

作者： Xuan Peng chao zheng Department of Mechanical Engineering Suzhou University of Science and TechnologySuzhou215009China Simshow High Technology Co. Ltd.Chengdu610042China Department of Mechanical and Industrial Engineering The University of IowaIowa CityIA 52242-1527USA

A novel continuum-based fast projection scheme is proposed for cloth *** geometry is described by NURBS,and the dynamic response is modeled by a displacement-only Kirchhoff-Love shell element formulated directly on NURBS *** fast projection method,which solves strain limiting as a constrained Lagrange problem,is extended to the continuum *** examples are studied to demonstrate the performance of the current *** proposed approach can be applied to grids of arbitrary topology and can eliminate unrealistic over-stretching efficiently if compared to spring-based methodologies.

关键词： Cloth simulation isogeometric analysis strain limiting fast projection

Quantum Transport and Surface Scattering in Magnetic Metallic Film

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Communications in Theoretical Physics 2008年第9期50卷 771-776页

作者： HU Yin DONG zheng-chao Department of Physics Huaiyin Teachers College Huaian 223001 China Key Laboratory for Chemistry of Low-Dimensional Materials of Jiangsu Province Huaian 223001 China

Taking into account the quantum size effect and the spin dependence of the electronic band structure,and including the spin dependence of the scattering from bulk impurities and two different sets of surface roughness,wepresent a theory on the electronic transport in magnetic film,in which the average autocorrelation function (ACF) forsurface roughness is described by a Gaussion *** result shows that the conductivity is a sensitive function ofsurface roughness and exchange *** is also found that in the thin film limit and in the lower-order approximationof the surface scattering,the total conductivity is given by a sum of conductivities of all the subbands and the two spinchannels,for each subband and each spin channel the scattering rates due to the impurities and two surfaces are additive.

关键词： magnetic metallic film surface scattering magnetic exchange splitting

Impact response and energy absorption of metallic buffer with entangled wire mesh damper

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Defence Technology（防务技术） 2024年第5期35卷 137-150页

作者： chao zheng Jun Wu Mangong Zhang Xin Xue Institute of Metal Rubber&Vibration Noise School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou 350116China Wuhan Second Ship Design and Research Institute Wuhan 430205China

An innovative metallic buffer consisting of series-connected hat-shaped entangled wire mesh damper(EWMD)and parallel springs are proposed in this work to enhance the reliability of engineering *** impact response and the energy dissipation mechanism of hat-shaped EWMD under different quasi-static compression deformations(2-7 mm)and impact heights(100-200 mm)are investigated using experimental and numerical *** results demonstrate distinct stages in the quasi-static mechanical characteristics of hat-shaped EWMD,including stiffness softening,negative stiffness,and stiffness *** loss factor gradually increases with increasing compression deformation before entering the stiffness hardening *** impact loads,the hat-shaped EWMD exhibits optimal impact energy absorption when it enters the negative stiffness stage(150 mm),resulting in the best impact isolation effect of metallic ***,the impact energy absorption significantly decreases when hat-shaped EWMD enters the stiffness hardening ***,quasi-static compression analysis after experiencing different impact loads reveals the disappearance of the negative stiffness ***,with increasing impact loads,the stiffness hardening point progressively shifts to an earlier stage.

关键词： Metallic buffer Hat-shaped EWMD Drop impact Energy absorption characteristics Mechanical behavior

Effects of Elevated CO_2 Concentration on the Biomasses and Nitrogen Concentrations in the Organs of Sainfoin(Onobrychis viciaefolia Scop.)

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Agricultural Sciences in China 2009年第4期8卷 424-430页

作者： ZHOU zheng-chao SHANGGUAN Zhou-ping College of Tourism and Environmental Sciences Shaanxi Normal University Xi＇an 710062 P.R. China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences Yangling 712100 P.R. China

In forage grasses, the nitrogen concentration is directly related to the nutritional value. The studies examined the hypothesis that global elevation of CO2 concentration probably affects the biomass, nitrogen （N） concentration, and allocation and distribution patterns in the organs of forage grasses. While sainfoin （Onobrychis viciaefolia Scop.） seedlings grew on a low nutrient soil in closed chambers for 90 days, they were exposed to two CO2 concentrations （ambient or ambient＋350 μmol mol^-1 CO2） without adding nutrients to them. After 90 days exposure to CO2, the biomasses of leaves, stems, and roots, and N concentrations and contents of different parts were measured. Compared with the ambient CO2 concentration, the elevated CO2 concentration increased the total dry matter by 25.07%, mainly due to the root and leaf having positive response to the elevated CO2 concentration. However, the elevated CO2 concentration did not change the proportions of the dry matters in different parts and the total plants compared with the ambient CO2 concentration. The elevated CO2 concentration lowered the N concentrations of the plant parts. Because the dry matter was higher, the elevated CO2 concentration had no effect on the N content in the plants compared to the ambient CO2 concentration. The elevated CO2 concentration promoted N allocations of the different parts significantly and increased N allocation of the underground part. The results have confirmed the previous suggestions that the elevated CO2 concentration stimulates plant biomass production and decreases the N concentrations of the plant parts.

关键词： biomass CO2 N allocation N content C/N ratio sainfoin

Population Synthesis for Mira Variables

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Chinese Journal of Astronomy and Astrophysics 2005年第4期5卷 419-425页

作者： Chun-Hua Zhu chao-zheng Zha Department of Physics Xinjiang University Urumqi 830046

By means of a population synthesis code, we investigate the Mira variables. Their birth rate （over 0.65yr^-1） and their number （～ 130000） in the Galaxy are estimated. For all possible Mira variables, ranges of their initial masses,pulsating periods, mass losses and lifetimes are given. We check our model with the observed Mira variables near the Sun and our results prove to be valid.

关键词： stars: late-type - stars: variables - stars: fundamental parameters

Effect of calcium content on inclusions during the ladle furnace refining process of AISI 321 stainless steel

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International Journal of Minerals,Metallurgy and Materials 2020年第11期27卷 1499-1507页

作者： chao Pan Xiao-jun Hu Jian-chao zheng Ping Lin Kuo-chih Chou State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China School of Metallurgy Northeastern UniversityShenyang 110819China Ruipu Technology Group Co. Ltd.Qingtian 323903China

The effect of three heat processes with different calcium contents on the evolution of inclusions during the ladle furnace refining process of AISI 321 stainless steel was *** size,morphology,and composition of the inclusions were analyzed by scanning electron microscopy and energy-dispersive X-ray *** the addition of aluminum and titanium,the primary oxide in the AISI 321 stainless steel was an AbOs—MgO—TiOx complex oxide,in which the mass ratio of AbOs/MgO was highly consistent with spinel(MgO・AbO3).After calcium treatment,the calcium content in the oxide increased *** calculations show that when the Ti content was 0.2wt%,the Al and Ca contents were less than 0.10wt%and 0.0005wt%,respectively,which was beneficial for the formation of liquid inclusions in molten ***,the modification mechanism of calcium on TiN-wrapped oxides in combination with temperature changes was discussed.

关键词： inclusions stainless steel calcium treatment thermodynamic calculation