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Solvable Catalyzed Birth-Death-Exchange Competition Model of Three Species

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Communications in Theoretical Physics 2009年第10期52卷 735-742页

作者： WANG Hai-feng LIN zhen-Quan GAO Yan ZHANG heng Department of Physics Teacthers College Shihezi University Shihezi 832003 China Department of Physics Wenzhou University Wenzhou 325027 China

A competition model of three species in exchange-driven aggregation growth is proposed. In the model, three distinct aggregates grow by exchange of monomers and in parallel, birth of species A is catalyzed by species B and death of species A is catalyzed by species C. The rates for both catalysis processes are proportional to kj^v and ky respectively, where ν（ω） is a parameter reflecting the dependence of the catalysis reaction rate of birth （death） on the catalyst aggregate＇s size. The kinetic evolution behaviors of the three species are investigated by the rate equation approach based on the mean-field theory： The form of the aggregate size distribution of A-species αk（t） is found to be dependent crucially on the two catalysis rate kernel parameters. The results show that （i） in case of ν ≤O, the form of ak （t） mainly depends on the competition between self-exchange of species A and species-C-catalyzed death of species A; （ii） in case of ν 〉 0, the form of αk（t） mainly depends on the competition between species-B-catalyzed birth of species A and species-C-catalyzed death of species A.

关键词： aggregation exchange-driven growth catalysis kinetic behaviour

Syntheses, Structures and Photoluminescence of Two New Europium（III） Coordination Polymers

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Chinese Journal of Structural Chemistry 2012年第8期31卷 1067-1074页

作者： LI Min HUANG Qun-Zeng feng Yu-Quan SHI heng-zhen Department of Chemistry Henan Institute of EducationZhengzhou 450046China College of Chemistry and Pharmacy Engineering Nanyang Normal UniversityNanyang 473061China

Two new europium （Ⅲ） coordination polymers formulated as Eu2（H20）a（ox）4]· （CsH6N）2-2H20 （1） and Eu2（ad）3（H20）4]＇0.25H20 （2）（H20x = oxalic acid, H2ad = adipic acid） have been synthesized from the self-assembly of lanthanide ions Eu^3＋ with flexible oxalic and adipic acid ligands, respectively. Structural analyses revealed that complex 1 exhibits three-dimensional metalorganic frameworks, and 2 has intricate two-dimensional interpenetrated metal-organic networks. In addition, the photoluminescent properties of complexes 1 and 2 were discussed in detail, which shows strong red emission, corresponding to ^5Do →^7F？ transition of Eu^3＋ ions.

关键词： coordination polymer lanthanide photoluminescence

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Lattice Boltzmann modeling of backward-facing step flow controlled by a synthetic jet

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Journal of Hydrodynamics 2023年第4期35卷 757-769页

作者： Tian-yang Lu Hai-bao Hu Jian Song Fan Zhang heng Zhang zhen-lin Xie feng Ren School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an710072China

This article investigates the effect of a synthetic jet(SJ)on the flow over a backward-facing step(BFS)in the weakly turbulent flow regime using the lattice Boltzmann *** SJ operates with various momentum coefficients Cμand forcing frequencies f^(*)_(jet).As Cμincreases,the reattachment length decreases,whereas increasing f^(*)_(jet) causes the reattachment length at first decrease and then increase.A minimum reattachment length appears at Cμ=0.3125,f^(*)_(jet)=1.6,corresponding to a 40%reduction compared with the uncontrolled *** mechanisms for the mediated flow are found:(1)A suitable control frequency leads to a lock-on state that prompts vertical momentum transfer and laminarizes the flow near the separation point,(2)Regular vortices emerge after wall reattachment in controlled *** Fourier and wavelet transform of the velocity near the separation point reveal that the monitored frequency becomes locked-on when f^(*)_(jet)>1.6,making the flow quasi-periodic and dramatically reducing the reattachment *** kinetic energy spectra indicate that the monitored frequencies are dominated by the forcing frequency and that active control laminarizes the local *** orthogonal decomposition is used to extract coherent structures at multiple *** the dominant mode,reattaching wake vortices are regulated by active *** the second mode,irregular wake vortices emerge after f^(*)_(jet)=2,which attenuates the SJ forcing and increases the reattachment *** study provides insights on typical flows past a BFS and will shed more light on the design of closed-loop control strategies for separation flows.

关键词： Lattice Boltzmann method(LBM) flow control synthetic jet proper orthogonal decomposition

Some Theorems in the Theory of Microstretch Thermomagnetoelectroelasticity

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Acta Mechanica Solida Sinica 2016年第2期29卷 145-158页

作者： zhen Yan WenJie feng Department of Engineering Mechanics Shijiazhuang Tiedao University

The linear dynamic theory of microstretch thermomagnetoelectroelasticity is studied in this ***,a reciprocity relation which involves two processes at different instants is established to form the basis of a uniqueness result and a reciprocal *** proof of the reciprocal theorem avoids both using the Laplace transform and incorporating the initial conditions into the equations of *** uniqueness theorem is derived with no definiteness assumption on the elastic constitutive *** the continuous dependence theorem is discussed upon two external data ***,the variational principle of Hamilton type which fully characterizes the solution of the mixed boundary-initial-value problem（mixed problem） is *** theorems lay a solid foundation for further theoretical and numerical studies on microstretch thermomagnetoelectroelastic materials.

关键词： microstretch theromagnetoelectroelasticity reciprocal theorem uniqueness theorem continuous dependence theorem variational principle

Spatial Characteristics and Influencing Factors of Urban Resilience from the Perspective of Daily Activity:A Case Study of Nanjing,China

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Chinese Geographical Science 2021年第3期31卷 387-399页

作者： SUN Honghu zhen feng School of Architecture and Urban Planning Nanjing UniversityNanjing 210093China Provincial Engineering Laboratory of Smart City Design Simulation&Visualization JiangsuNanjing UniversityNanjing 210093China

Based on the connotation of urban resilience and the main contradictions of China's urbanization,urban resilience is placed within the main daily activities contradictory scene of the urban man-land system to build a theoretical framework of urban activity *** on geographic big data,this study identifies the spatial characteristics of activity resilience,reveals the impact of activity environment on activity resilience in Nanjing,and proposes *** main conclusions are as follows.1)Activity resilience presents a composite spatial structure of circles and clusters,and most areas are resilient but at a low level.2)There are significantly positive and negative global autocorrelation between activity resilience and activity scale,and activity ***,there also exists a local spatial autocorrelation with the opposite positive and negative trends.3)Activity environment has a significant effect on activity resilience,and the degree and direction of influence among different dimensions and regions are heterogeneous.4)For activity resilience,it is necessary to increase the matching degree between the scale and stability of activities,and reduce the excessive concentration and flow of *** the activity environment,it is necessary to improve the accessibility of the ecological environment,strengthen the high-quality supply of the infrastructure environment,optimize the balance of the location environment,and promote the inclusiveness of the social environment.

关键词： urban resilience daily activity contradiction between supply and demand big data spatial characteristics Nanjing China

Synthesis and Crystal Structure of Methyl 12-Bromo-13,14-furoxan-deisopropyldehydroabietate

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Chinese Journal of Structural Chemistry 2006年第10期25卷 1209-1212页

作者： PAN Ying-Ming ZHANG Ye WANG heng-Shan CHEN zhen-feng WU Qiang GE Chun-Yu ZHANG Yong College of Chemistry and Chemical Engineering Guangxi Normal University Guilin 541004 China College of Chemistry and Chemical Engineering Suzhou University Suzhou 215006 China

Methyl 12-bromo-13,14-furoxan-deisopropyldehydroabietate, C18H22BrN2O4, has been synthesized and characterized by IR,^1H NMR, ^13C NMR and single-crystal X-ray diffraction method. It crystallizes in orthorhombic, space group P212121 with a = 6.652（2）, b = 12.832（4）, c = 20.483（6）°A, V = 1748.5（9） °A^3, Z = 4, Mr = 410.29, D, = 1.559 g/cm^3, λ= 0.71070°A, μ（MoKα） = 2.377 mm^-1, F（000） = 844, the final R = 0.0243 and wR = 0.0533 for 3780 observed reflections with I〉 2σ（I）. The C-H and bromine atom are involved in intermolecular hydrogen bonds which link the molecules into a one-dimensional chain.

关键词： methyl 12-bromo-13,14-furoxan-deisopropyldehydroabietate furoxan synthesis crystal structure

D DT Theorem over square-free numbers in short interval

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Frontiers of Mathematics in China 2017年第2期12卷 367-375页

作者： Bin feng zhen CUI School of Mathematics Sciences Shanghai Jiao Tong University Shanghai 200240 China College Of Mathematics and Statistics Yangtze Normal University Fuling 408100 China

We study the Cesaro means related to the divisor function. We show that the DDT Theorem holds over square-free numbers in short interval, which generalizes some results established by Deshouillers-Dress-Tenenbaum and ... 详细信息

关键词： Selberg-Delang method arcsine law square-free number

Mechanisms responsible for the effect of median nerve electrical stimulation on traumatic brain injuryinduced coma: orexin-A-mediated N-methyl-Daspartate receptor subunit NR1 upregulation

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Neural Regeneration Research 2016年第6期11卷 951-956页

作者： zhen feng Qing Du Department of Rehabilitation the First Affiliated Hospital of Nanchang University

Electrical stimulation of the median nerve is a noninvasive technique that facilitates awakening from coma. In rats with traumatic brain injury-induced coma, median nerve stimulation markedly enhances prefrontal cortex expression of orexin-A and its receptor, orexin receptor 1. To further understand the mechanism underlying wakefulness mediated by electrical stimulation of the median nerve, we evaluated its effects on the expression of the N-methyl-D-aspartate receptor subunit NR1 in the prefrontal cortex in rat models of traumatic brain injury-induced coma, using immunohistochemistry and western blot assays. In rats with traumatic brain injury, NR1 expression increased with time after injury. Rats that underwent electrical stimulation of the median nerve（30 Hz, 0.5 ms, 1.0 m A for 15 minutes） showed elevated NR1 expression and greater recovery of consciousness than those without stimulation. These effects were reduced by intracerebroventricular injection of the orexin receptor 1 antagonist SB334867. Our results indicate that electrical stimulation of the median nerve promotes recovery from traumatic brain injury-induced coma by increasing prefrontal cortex NR1 expression via an orexin-A-mediated pathway.

关键词： stimulation traumatic median cortex subunit minutes NMDAR markedly antagonist aspartate

Construction of bienzyme biosensors based on combination of the one-step electrodeposition and covalent-coupled sol-gel process

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Science China Chemistry 2009年第12期52卷 2269-2274页

作者： LI feng WANG zhen feng Yan Key Laboratory of Eco-Chemical Engineering Ministry of EducationCollege of Chemistry and Molecular EngineeringQingdao University of Science and TechnologyQingdao 266042China

Horseradish peroxidase (HRP) and glucose oxidase (GOD) bienzyme biosensor was constructed by in-situ formation of the organic-inorganic biocomposite film based on the one-step electrodeposition and covalent-coupled sol-gel process. The electrodeposition was performed in the solution containing functional inorganic precursor possessing the epoxy groups,γ-glycidoxypropyltrimethoxysiloxane (GPTMS),a biopolymer chitosan (CS),HRP and GOD. The covalent-coupled sol-gel process was formed by self-hydrolysis and self-condensation of GPTMS,followed by in-situ covalent cross-linking of CS,HRP and GOD through covalent reaction between amino groups and epoxy groups. The developed bienzyme biosensor presented high stability in acidic solution owing to the covalent-coupled organic-inorganic hybridization. Compared with the non-hybrid HRP-GOD/CS/Au electrode,the bienzyme biosensor of HRP-GOD/GPTMS/CS/Au showed improved sensitivity and a wider linear range for the determination of glucose. The linear response of the developed HRP-GOD/GPTMS/ CS/Au biosensor for the determination of glucose ranged from 1 to 351 μmol/L with a detection limit of 0.3 μmol/L.

关键词： chitosan GPTMS glucose biosensor