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Maxwell-Chern-Simons Casimir Force Between Perfectly Conducting Parallel lines

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Communications in Theoretical Physics 2001年第10期36卷 431-432页

作者： zheng Tai-Yu zheng li li Chang-Song The Institute of Theoretical Physics Northeast Normal University Changchun 130022 China The Center of Theoretical Physics Jilin University Changchun 130000 China The Institute of Theoretical Physics Northeast Normal University Changchun 130022 China Technique School of Yanbian Yanji 133000 Jilin Province China

Using Feynman path integral method we calculate the Casimir force of Maxwell Chern Simons Abelian gauge field between perfectly conducting parallel lines.

关键词： Casimir force, path integral method, Maxwell Chern Simons gauge field

Chiral metal phosphonates: assembly, structures and functions

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Science China Chemistry 2020年第5期63卷 619-636页

作者： Guo-Guo Weng li-Min zheng State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical EngineeringCollaborative Innovation Centre of Advanced MicrostructuresNanjing UniversityNanjing 210023China

As an important class of inorganic-organic hybrid materials, metal phosphonates can exhibit versatile structures, interesting functions and high water and thermal stabilities. Despite a large number of metal phosphonates reported in the past two decades,the development of chiral metal phosphonates is still in its infancy. This review summarizes the current status in this topical field including the synthetic strategies, the crystal structures of chiral metal phosphonates reported thus far, and their physical and chemical properties. Future challenges in this promising field are also discussed.

关键词： chiral metal phosphonate structure property

Small modifications of endo-functionalized cavities lead to large changes in molecular interaction in water

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Science China Chemistry 2025年第1期 369-376页

作者： Song-Meng Wang Hao Nian Yan-Fang Wang li-Shuo zheng Yu-Tao zheng Yi-Wei Dong liping Huang Xiaoping Wang Wei Jiang liu-Pan Yang Department of Chemistry Southern University of Science and Technology School of Chemistry and Pharmaceutical Sciences State Key Laboratory for Chemistry and Molecular Engineering of Medicinal ResourcesGuangxi Normal University School of Pharmaceutical Science Hengyang Medical School University of South China

Studying molecular recognition in aqueous environments is crucial for understanding biological processes. Herein, we present a series of N-doped endo-functionalized anthracene-based cavities by introducing inward-directed pyridine units. The subtle modifications can significantly affect the binding properties of these receptors, which is similar to the mutations in biological systems. Combining theoretical calculations and molecular recognition experiments demonstrated that these “mutations” have an impact on the hydrophobicity and charge distribution of the hosts, consequently significantly influencing molecular *** is crucial for understanding the intricate mechanisms of molecular-level interactions in biological receptors.

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Gold nanoparticles with surface-anchored chiral poly（acryloyI-L（D）-valine） induce differential response on mesenchymal stem cell osteogenesis

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Nano Research 2016年第12期9卷 3683-3694页

作者： Jun Deng Honghao zheng Xiaowen zheng Mengyun Yao zheng li Changyou Gao MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering ZhejiangUniversity Hangzhou 310027 China

Chirality is one of the most distinctive biochemical signatures of life, and plays crucial roles in maintaining normal functions of living cells or organisms. Pioneering work from another group has demonstrated the dependency of cell differentiation on the chirality of nano-coated substrates, but the effect of the chiral surface of nanoparticles on stem cell fates has not been investigated. In this study, the influence of molecular chiral poly（acryloyl-L（D）-valine）（L（D）- PAV）-anchored gold nanoparticles （L（D）-PAV-AuNPs） on the differentiation of mesenchymal stem cells （MSCs） was investigated. Though osteogenic differentiation of MSCs was not affected by D-PAV-AuNPs, it was significantly promoted by L-PAV-AuNPs in terms of calcium deposition, alkaline phosphatase （ALP） activity, and expression of collagen type I and osteocalcin （OCN） at both mRNA and protein levels. L-PAV-AuNPs could activate the P38 mitogen-activated protein kinase （MAPK） pathway, and may exert mechanical stress on MSCs because of high amounts of internalization. These results provide new insights on surface chirality at the nanoscale as a direct regulator to guide the differentiation of MSCs, and the use of these nanomaterials for strategic regenerative medicine.

关键词： chiralpoly(acryloyl-L(D)-valine) gold nanoparticles mesenchymal stem cells osteogenic differentiation

Conjugate Hydrocyanation of Chalcone Derivatives Using Ethyl Cyanoacetate as an Organic Cyanide Source

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Chinese Journal of Chemistry 2017年第7期35卷 1179-1184页

作者： zheng li Junjun Yin College of Chemistry and Chemical Engineering Northwest Normal University Lanzhou Gansu 730070 China

The conjugate hydrocyanation of chalcone derivatives using ethyl cyanoacetate as an organic cyanide source at room temperature under open air and transition metal-free conditions was described. The protocol has advantages of using relatively cheap, less toxic, stable and easy-to-handle cyanating reagent, high yield, and mild reaction condi- tion.

关键词： hydrocyanation chalcone derivative ethyl cyanoacetate organic cyanide source

ELECTRIC FIELD EFFECTS ON YOUNG'S MOLULUS OF NANOWIRES

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Acta Mechanica Solida Sinica 2009年第6期22卷 511-523页

作者： Xiaojing zheng li Qiao Key Laboratory of Mechanics on Western Disaster and Environment Ministry of Education PRC Department of Mechanics and Engineering Science College of civil Engineering and Mechanics Lanzhou University Lanzhou Gansu 730000 China

As an important component of nanodevices and nanomachine constructions, the mechanical performance of nanowires （NWs） has been a subject of intense research efforts due to gaining relevance in controlling functionality of nanoelectromechanical systems （NEMS）; meanwhile, one of the characteristics of the NEMS is the dependence of the functionality of the systems upon the applied electric field. The study of the electric effects on the Young＇s modulus of nanostructures is of certain usefulness in the design of NEMS and the precise measurement of mechanical properties of one-dimensional nanostructures. This paper reviews the origin of the size-dependence of the elastic property of NWs and the factors influencing the discrepancies and inconsistencies in the measured values of the Young＇s modulus for the NW, besides the surface effects, nonlinear effects, the electromechanical coupling effects as a possible effect responsible for the differences in quantitative and qualitative performance of the measured Young＇s modulus for the NWs versus the diameter are clarified.

关键词： nanowires Young's modulus molecular dynamics simulations continuum mechanics theory electric effects

Evolution and Generation of Dynamics of Two-Mode Squeezed States of Time-Dependent Coupled Boson System

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Communications in Theoretical Physics 2008年第10期50卷 955-960页

作者： ZHANG Xue zheng Tai-Yu zheng li Institute of Theoretical Physics Northeast Normal University Changchun 130000 China College of Information Science and Engineering Dalian Polytechnic University Dalian 116034 China

The system of the Hamiltonian involving a driving part,a single mode part,and a two-mode squeezedone and a two-mode coupled one is discussed using the Lewis-Riesenfeld invariant *** time evolution operatoris *** the initial state is a coherent state,the quantum fluctuation of the system is calculated,and it isdependent on the squeezed part and the two-mode coupled part,but not dependent on the driving one.

关键词： two-mode squeezed states Lewis Riesenfeld invariant theory time evolution operator

Efficient schedulability analysis for mixed-criticality systems under deadline-based scheduling

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Chinese Journal of Aeronautics 2014年第4期27卷 856-866页

作者： Chen Yao li Qiao li zheng Xiong Huagang School of Electronic and Information Engineering Beihang University

Safety-critical avionics systems which become more complex and tend to integrate multiple functionalities with different levels of criticality for better cost and power efficiency are subject to certifications at various levels of rigorousness. In order to simultaneously guarantee temporal constraints at all different levels of assurance mandated by different criticalities, novel scheduling techniques are in need. In this paper, a mixed-criticality sporadic task model with multiple virtual deadlines is built and a certification-cognizant dynamic scheduling approach referred as earliest virtual-deadline first with mixed-criticality（EVDF-MC） is considered, which exploits different relative deadlines of tasks in different criticality modes. As for the corresponding schedulability analysis problem, a sufficient and efficient schedulability test is proposed on the basis of demand-bound functions derived in the mixed-criticality scenario. In addition, a modified simulated annealing（MSA）-based heuristic approach is established for virtual deadlines assignment. Experiments performing simulations with randomly generated tasks indicate that the proposed approach is computationally efficient and competes well against the existing approaches.

关键词： Avionics systems Mixed-criticality Real-time scheduling Schedulability analysis Simulated annealing

DYNAMIC FRACTURE ANALYSIS OF AGED GLASSY POLYCARBONATE BY THE METHOD OF CAUSTICS

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Acta Mechanica Solida Sinica 2013年第5期26卷 448-457页

作者： Guiyun Gao zheng li Mehrdad Negahban State Key Lab for Turbulence and Complex Systems and College of Engineering Peking University Department of Engineering Mechanics University of Nebraska-Lincoln

The purpose of this work is to investigate the dynamic fracture properties of glassy polycarbonate （PC） with different aging times. The optical method of caustics is adopted in which the shadow spot patterns are recorded by a high speed camera during the dynamic fracture process. Then, the dynamic crack propagation, the stress intensity factor （SIF） and the dynamic fracture toughness of aged PC are obtained through an analysis of the characteristic size of caustic pattern. Moreover, by combining with the investigation of the fracture surface and the energy release rate analysis, the influence of aging time on the dynamic fracture behavior is discussed. Results show that the dynamic fracture toughness and critical energy release rate of PC decreases with aging time for short aging times, whereas they have little change or even increase for longer aging times. Therefore, aging modifies the mechanical properties especially the dynamic fracture properties of PC nonlinearly, not linearly as generally thought of.

关键词： polycarbonate physical aging dynamic fracture stress intensity factor