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WEAK-STRONG UNIQUENESS FOR THREE DIMENSIONAL INCOMPRESSIBLE ACTIVE LIQUID CRYSTALS
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作者 Fan YANG congming li 《Acta Mathematica Scientia》 SCIE CSCD 2024年第4期1415-1440,共26页
The hydrodynamics of active liquid crystal models has attracted much attention in recent years due to many applications of these models.In this paper,we study the weak-strong uniqueness for the Leray-Hopf type weak so... The hydrodynamics of active liquid crystal models has attracted much attention in recent years due to many applications of these models.In this paper,we study the weak-strong uniqueness for the Leray-Hopf type weak solutions to the incompressible active liquid crystals in R^(3).Our results yield that if there exists a strong solution,then it is unique among the Leray-Hopf type weak solutions associated with the same initial data. 展开更多
关键词 analysis of parabolic and elliptic types weak-strong uniqueness active liquid crystals weak solution energy equality
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CLASSIFICATION OF POSITIVE SOLUTIONS FOR NONLINEAR DIFFERENTIAL AND INTEGRAL SYSTEMS WITH CRITICAL EXPONENTS 被引量:8
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作者 Wenxiong Chen congming li 《Acta Mathematica Scientia》 SCIE CSCD 2009年第4期949-960,共12页
We classify all positive solutions for the following integral system:{ui(x)=∫Rn1/│x-y│^n-α fi(u(y))dy,x∈R^n,i=1,…,m,0〈α〈n,and u(x)=(u1(x),u2(x)…,um(x)).Here fi(u), 1 ≤ i ≤m, monotone non... We classify all positive solutions for the following integral system:{ui(x)=∫Rn1/│x-y│^n-α fi(u(y))dy,x∈R^n,i=1,…,m,0〈α〈n,and u(x)=(u1(x),u2(x)…,um(x)).Here fi(u), 1 ≤ i ≤m, monotone nondecreasing are real-valued functions of homogeneous degree n+α/n-α and are monotone nondecreasing with respect to all the independent variables U1, u2, ..., urn.In the special case n ≥ 3 and α = 2. we show that the above system is equivalent to thefollowing elliptic PDE system:This system is closely related to the stationary SchrSdinger system with critical exponents for Bose-Einstein condensate 展开更多
关键词 integral and PDE systems positive solutions method of moving planes radial symmetry UNIQUENESS
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Dynamic Analysis and Dimensional Synthesis of Easy-to-Protect Large-Load Robot for Extracting Fermented Grains
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作者 Yubin Zhang Jinzhu Zhang +2 位作者 congming li Xiaoyan Xiong Hongjie Du 《Journal of Beijing Institute of Technology》 EI CAS 2023年第4期529-550,共22页
To improve the operation situation of difficulty and low efficiency in the extraction of fermented grains(FG),a high-load and large-workspace reclaiming robot for ceramic cylinder fermentation is designed,and a reclai... To improve the operation situation of difficulty and low efficiency in the extraction of fermented grains(FG),a high-load and large-workspace reclaiming robot for ceramic cylinder fermentation is designed,and a reclaiming effector is designed according to the operating characteristics.Firstly,the kinematics and singularity of the mechanism are analyzed.A multi-domain polar coordinate search method is proposed to obtain the workspace and the volume of the mechanism.Secondly,the dynamic modeling is completed and the example simulation is carried out.Thirdly,the motion-force transmission index of the mechanism is established.And based on the global transmissibility and the good-transmission workspace,the dimensional synthesis of the driving mechanism is completed by using the performance atlas-based method.Finally,aiming at the regular workspace size,stiffness and loading capacity,the Pareto optimal solution set of the executive mechanism dimension is obtained by using the multi-objective particle swarm optimization(MOPSO)algorithm.This paper can provide a theoretical basis for the optimal design and control of FG reclaiming robot. 展开更多
关键词 reclaiming robot configuration design performance index dynamic modeling multi-objective optimization
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探究Cu/ZnO相互作用对CO_(2)加氢制甲醇反应性能的影响 被引量:5
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作者 李聪明 陈阔 +2 位作者 王晓月 薛楠 杨恒权 《物理化学学报》 SCIE CAS CSCD 北大核心 2021年第5期201-212,共12页
利用可再生绿氢和二氧化碳生产甲醇是未来解决二氧化碳排放的根本途径之一,而研发高效稳定的甲醇合成催化剂是决定整个合成工艺的关键因素之一。负载型催化剂(金属纳米颗粒负载在载体表面)在甲醇合成反应中占有重要地位,而金属-载体相... 利用可再生绿氢和二氧化碳生产甲醇是未来解决二氧化碳排放的根本途径之一,而研发高效稳定的甲醇合成催化剂是决定整个合成工艺的关键因素之一。负载型催化剂(金属纳米颗粒负载在载体表面)在甲醇合成反应中占有重要地位,而金属-载体相互作用常被用来稳定金属颗粒,调控催化剂活性、选择性和稳定性。尽管对金属–载体相互作用进行了大量研究,但是关于不同强度金属–载体相互作用对催化剂的结构和性能影响的理解仍然是匮乏的。本工作合成了三种具有不同强度金属–载体相互作用的Cu/ZnO-SiO_(2)催化剂,探究了其对CO_(2)加氢制甲醇反应性能的影响。H2-TPR和XPS表征结果表明,通过改变沉淀顺序可以调变Cu/ZnO-SiO_(2)催化剂中金属–载体相互作用,FT-IR结果证实了Cu物种均以CuO的形式存在。TEM、XRD和N2O化学吸附结果表明Cu/ZnO强的相互作用促进了Cu物种的分散,提高了CO_(2)转化率和催化剂的稳定性。正如预期,Re-CZS催化剂实现了最高的CO_(2)转化率(12.4%),而Co-CZS催化剂与Nor-CZS催化剂的CO_(2)转化率分别为12.1%和9.8%。反应相同时间后,标准化的CO_(2)转化率降低顺序是:Re-CZS(75%)>Co-CZS(70%)>Nor-CZS(65%)。与Co-CZS和Nor-CZS催化剂不同,Re-CZS催化剂的甲醇选择性随着反应进行逐步增加而后趋于稳定。对该催化剂在反应过程中的结构演变进行表征,结果显示,Re-CZS催化剂Cu/ZnO间强的相互作用引起了催化剂结构重构,促使体相中的ZnO物种向催化剂表面Cu物种迁移,形成了更多的Cu/ZnO界面,有利于甲醇的生成。本工作为合理设计有效催化剂提供一个可行策略。 展开更多
关键词 Cu/ZnO-SiO_(2)催化剂 金属–载体相互作用 CO_(2)加氢 甲醇
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RADIAL SYMMETRY FOR SYSTEMS OF FRACTIONAL LAPLACIAN 被引量:2
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作者 李从明 吴志刚 《Acta Mathematica Scientia》 SCIE CSCD 2018年第5期1567-1582,共16页
In this paper, we consider systems of fractional Laplacian equations in ]I^n with nonlinear terms satisfying some quite general structural conditions. These systems were categorized critical and subcritical cases. We ... In this paper, we consider systems of fractional Laplacian equations in ]I^n with nonlinear terms satisfying some quite general structural conditions. These systems were categorized critical and subcritical cases. We show that there is no positive solution in the subcritical cases, and we classify all positive solutions ui in the critical cases by using a direct method of moving planes introduced in Chen-Li-Li [11] and some new maximum principles in Li-Wu-Xu [27]. 展开更多
关键词 system of fractional Laplacian method of moving planes maximum principles with singular point Kelvin transform
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Classification of anti-symmetric solutions to the fractional Lane-Emden system
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作者 congming li Ran Zhuo 《Science China Mathematics》 SCIE CSCD 2023年第4期723-744,共22页
We study the anti-symmetric solutions to the Lane-Emden type system involving fractional Laplacian(-△)^(s)(0<s<1).First,we obtain a Liouville type theorem in the often-used defining space L_(2s).An interesting ... We study the anti-symmetric solutions to the Lane-Emden type system involving fractional Laplacian(-△)^(s)(0<s<1).First,we obtain a Liouville type theorem in the often-used defining space L_(2s).An interesting lower bound on the solutions is derived to estimate the Lipschitz coefficient in the sub-linear cases.Considering the anti-symmetric property,one can naturally extend the defining space from L_(2s) to L_(2s+1).Surprisingly,with this extension,we show the existence of non-trivial solutions.This is very different from the previous results of the Lane-Emden system. 展开更多
关键词 Lane-Emden system fractional Laplacian maximum principle Liouville type theorems EXISTENCE
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