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Effects of Temperature and Liquid Nitrogen(LN2)on Coal’s Mechanical and Acoustic Emission(AE)Properties

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Fluid Dynamics & Materials Processing 2024年第6期20卷 1181-1202页

作者： teng teng Yuhe Cai Linchao Wang Yanzhao zhu Inner Mongolia Research Institute China University of Mining and Technology-BeijingOrdos017001China Beijing Key Laboratory for Precise Mining of Intergrown Energy and Resources China University of Mining and Technology-BeijingBeijing100083China School of Civil Engineering and Architecture Xi’an University of TechnologyXi’an710048China

Liquid nitrogen has shown excellent performances as a good fracturing medium in the extraction of unconventional natural gas,and its application in coalbed methane extraction is currently a research *** study focuses on the acoustic emission properties of coal specimens treated utilizing liquid nitrogen with varying initial temperatures in a three-point bending *** examination of the load-displacement curves of the considered coal samples,their mechanical properties are also revealed for different initial temperatures and cycling *** findings demonstrate a gradual decline in the maximum load capacity of coal rock as the temperature ***,when subjected to the same temperature,an escalation in the cycling frequency leads to a reduction in the peak load of coal *** suggests that both temperature and cycling frequency exert a notable impact on the fracturing efficacy of liquid ***-thaw cycling treatments and exposure to high-temperature conditions can activate preexisting damage in the coal rock,and,accordingly,influence its mechanical *** particular,throughout the progressive loading of coal rock samples,the failure mechanisms are predominantly characterized by the occurrence of tensile cracks,succeeded by the development,spread,and fracture of shear fissures.

关键词： Liquid nitrogen fracturing three-point bending experiment mechanical characteristics

Asymptotic Stability for One-dimensional Motion of Non-Newtonian Compressible Fluids

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Acta Mathematicae Applicatae Sinica 2014年第1期30卷 99-110页

作者： Xiao-ding shi teng WANG Zhen ZHANG School of Science Beijing University of Chemical Technology Academy of Mathematics and Systems Science Chinese Academy of Sciences School of Mechanical and Electrical Engineering Beijing University of Chemical Technology

Rarefaction wave solutions for a one-dimensional model system associated with nomNewtonian compressible fluid are investigated in terms of asymptotic stability. The rarefaction wave solution is proved to be asymptotically stable, provided the initial disturbance is suitably small. The proof is given by the elemental L2 energy method.

关键词： non-Newtonian fluid asymptotic stability global solution

Blow-up Dynamics of L^2 Solutions for the Davey–Stewartson System

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Acta Mathematica Sinica,English Series 2015年第3期31卷 411-429页

作者： shi Hui zhu Department of Mathematics Sichuan Normal University

We study the blow-up solutions for the Davey-Stewartson system（D-S system, for short）in L2x（R2）. First, we give the nonlinear profile decomposition of solutions for the D-S system. Then, we prove the existence of minimal mass blow-up solutions. Finally, by using the characteristic of minimal mass blow-up solutions, we obtain the limiting profile and a precisely mass concentration of L2 blow-up solutions for the D-S system.

关键词： Davey-Stewartson system minimal mass blow-up solution profile decomposition limiting profile mass concentration

Transitions in a Logistic Growth Model Induced by Noise Coupling and Noise Color

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Communications in Theoretical Physics 2006年第1X期46卷 175-182页

作者： shi Jin zhu shi-Qun School of Physical Science and Technology Suzhou University Suzhou 215006 China

With unified colored noise approximation, the logistic growth model is used to analyze cancer cell population when colored noise is included. It is found that both the coupling between noise terms and the noise color can induce continuous first-order-like and re-entrance-like phase transitions in the system. The coupling and the noise color can also increase tumor cell growth for small number of cell mass and repress tumor cell growth for large number of cell mass. It is shown that the approximate analytic expressions are consistent with the numerical simulations.

关键词： logistic growth model first-order-like phase transition re-entrance-like phase transition colored noise

Progress in functional studies of transition metal borides

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Chinese Physics B 2021年第10期30卷 98-107页

作者： teng Ma Pinwen zhu Xiaohui Yu State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China

In recent years,transition metal borides(TMBs)have attracted much attention because they are considered as potential superhard materials and have more abundant crystal structures compared with traditional superhard *** far,however,no superhard materials have been found in TMBs.A large number of structures and potential new properties in TMBs are induced by the various hybridization ways of boron atoms and the high valence electrons of transition metals,which provide many possibilities for its *** most TMBs have layered structures,which make TMBs have the potential to be a two-dimensional(2D)*** 2D materials have novel properties,but the research on 2D TMBs is still nearly *** this paper,the research progress of TMBs is summarized involving structure,mechanical properties,and multifunctional *** strong covalent bonds of boron atoms in TMBs can form one-dimensional,twodimensional,and three-dimensional substructures,and the multiple electron transfer between transition metal and boron leads to a variety of chemical bonds in TMBs,which are the keys to obtain high hardness and multifunctional properties of *** research on the multifunctional properties of TMBs,such as superconductors,catalysts,and high hardness ferromagnetic materials,is of great significance to the discovery of new multifunctional hard materials.

关键词： transition metal borides crystal structure hardness multifunctional properties

Strain hardening behavior of Mg-Y alloys after extrusion process

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Journal of Magnesium and Alloys 2019年第4期7卷 672-680页

作者： Chaoyue Zhao Ziyan Li Jiahui shi Xianhua Chen teng Tu zhu Luo Renju Cheng Andrej Atrens Fusheng Pan The State Key Laboratory of Mechanical Transmissions College of Materials Science and EngineeringChongqing UniversityChongqing 400045China Chongqing Academy of Science and Technology Chongqing 401123China School of Mechanical and Mining Engineering The University of QueenslandSt Lucia4072 QldAustralia

The strain hardening is an effective mode of enhancing mechanical properties in *** this work,the strain hardening behaviors of Mg-xY(x=1,2,and 3 wt%)after extrusion process was investigated using uniaxial tensile *** suggest that the Mg-xY alloys are composed ofα-Mg with a little amount of Mg24Y5 *** average grain size reduces from 19.8μm to 12.2μm as the Y content adds from 1 wt%to 2 wt%.Nevertheless,when Y content reaches 3 wt%,the grain size reaches to 12.9μm,which is close to that of *** strain hardening rate decreases from 883 MPa to 798 MPa at(σ-σ0.2)=40 MPa,and Mg-2Y and Mg-3Y have the similar strain hardening ***,Mg-1Y shows an obvious ascending stage after the steep decreasing stage,which is mainly caused by the activation of *** strain hardening behavior of Mg-xY is explained based on understanding the roles of the deformation mechanisms via deformation microstructure analysis and Visco-Plastic Self Consistent(VPSC)*** variation of strain hardening characteristics with increasing Y content is related to the effects of grain size and texture.

关键词： Mg-Y alloy Strain hardening Texture Twinning VPSC

Regularity of inverse mean curvature flow in asymptotically hyperbolic manifolds with dimension 3

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Science China Mathematics 2021年第6期64卷 1109-1126页

作者： shi Yuguang zhu Jintian Key Laboratory of Pure and Applied Mathematics School of Mathematical SciencesPeking UniversityBeijing 100871China

By using the nice behavior of the Hawking mass of the slices of a weak solution of inverse mean curvature flow in three-dimensional asymptotically hyperbolic manifolds, we are able to show that each slice of the flow is star-shaped after a long time, and then we get the regularity of the weak solution of inverse mean curvature flow in asymptotically hyperbolic manifolds. As an application, we prove that the limit of the Hawking mass of the slices of a weak solution of inverse mean curvature flow with any connected C^(2)-smooth surface as initial data in asymptotically anti-de Sitter-Schwarzschild manifolds with positive mass is greater than or equal to the total mass, which is completely different from the situation in the asymptotically flat case.

关键词： regularity inverse mean curvature flow asymptotically hyperbolic Hawking mass

Seedling morphogenesis:when ethylene meets high ambient temperature

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aBIOTECH 2022年第1期3卷 40-48页

作者： Junjie shi Ziqiang zhu Jiangsu Key Laboratory for Biodiversity and Biotechnology College of Life SciencesNanjing Normal UniversityNanjing 210023China

Unlike animals,plant development is plastic and sensitive to environmental *** example,Arabidopsis thaliana seedlings display distinct growth patterns when they are grown under different light or temperature conditions.M oreover,endogenous plant hormone such as ethylene also impacts seedling morphol *** induces hypocotyl elongation in light-grown seedlings but strongly inhibits hypocotyl elongation in etiolated(dark-grown)*** characteristic ethylene response in etiolated seedlings is the formation of exaggerated apical *** it is well known that high ambient temperature promotes hypocotyl elongation in light-grown seedlings(thermomor-phogenesis),ethylene suppresses *** another side,high ambient temperature also inhibits the ethylene-responsive hypocotyl shortening and exaggerated hook for mation in etiolated ***,the simplest phytohormone ethylene exhibits almost the most complicated responses,depending on temperature and/or light *** this review,we will focus on two topics related to the main theme of this special issue(response to high temperature):(1)how does high temperature suppress ethylene-induced seedling morphology in dark grown seedlings,and(2)how does ethylene inhibit high temperature-induced seedling growth in light-grown *** ethylene biosynthesis through antisense technology was the hallmark event in plant genetic engi-neering in 1990,we assume that manipulations on plant ethylene signaling in agricultural plants may pave the way for coping with climate change in future.

关键词： Ethylene Thermomorphogenesis EIN3 EBF1/EBF2 Arabidopsis thaliana

Network selection based on multiple attribute decision making and group decision making for heterogeneous wireless networks

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The Journal of China Universities of Posts and Telecommunications 2012年第5期19卷 92-98,114页

作者： shi Zheng zhu Qi Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Laboratory on Wideband Wireless Communications and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

One of the key issues for radio resources management is network selection strategy in heterogeneous scenarios. In order to provide ubiquitous service, the paper puts forward a network selection algorithm based on multiple attribute decision making （MADM） and group decision making （GDM）. Firstly, the proposed algorithm acquires attribute weights＇ vectors of the subjective and objective decision makers based on MADM, and then the two attribute weights＇ vectors are synthesized to be a new attribute weights＇ vector by using GDM. Considering that the results of GDM should be reasonable and convincible, the criterion of consistency is adopted for judging the compatibility of group judgments. More specit]cally, the algorithm takes into account not only objective attributes of networks but also the preference of subscribers and traft]c class Hence it guarantees that the subscribers can not select the networks with poor performance depending on their preference. The simulation results show that the proposed algorithm can effectively reduce the handoff number and provide subscribers with satisfactory quality of service （QoS）.

关键词： heterogeneous wireless networks group decision making compatibility criterion analytic hierarchy process entropy method