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Critical Exponents for Fast Diffusion Equations with Nonlinear Boundary Sources

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Communications in Mathematical Research 2011年第2期27卷 97-104页

作者： WANG lu-sheng WANG ZE-jia School of Mathematics Jilin University Changehun 130012

In this paper,we study the large time behavior of solutions to a class of fast diffusion equations with nonlinear boundary sources on the exterior domain of the unit *** are interested in the critical global exponent q_o and the critical Fujita exponent q_c for the problem considered,and show that q_o=q_c for the multidimensional Non-Newtonian polytropic filtration equation with nonlinear boundary sources,which is quite different from the known results that q_o〈q_c for the onedimensional case;moreover,the value is different from the slow case.

关键词： exterior domain critical global exponent critical Fujita exponent fast diffusion equation

Understanding the local structure and thermophysical behavior of Mg-La liquid alloys via machine learning potential

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 439-449页

作者： jia Zhao Taixi Feng Guimin lu National Engineering Research Center for Integrated Utilization of Salt Lake Resource East China University of Science and TechnologyShanghai 200237China Joint International Laboratory for Potassium and Lithium Strategic Resources East China University of Science and TechnologyShanghai 200237China

The local structure and thermophysical behavior of Mg-La liquid alloys were in-depth understood using deep potential molecular dynamic(DPMD) simulation driven via machine learning to promote the development of Mg-La alloys. The robustness of the trained deep potential(DP) model was thoroughly evaluated through several aspects, including root-mean-square errors(RMSEs), energy and force data, and structural information comparison results;the results indicate the carefully trained DP model is reliable. The component and temperature dependence of the local structure in the Mg-La liquid alloy was analyzed. The effect of Mg content in the system on the first coordination shell of the atomic pairs is the same as that of temperature. The pre-peak demonstrated in the structure factor indicates the presence of a medium-range ordered structure in the Mg-La liquid alloy, which is particularly pronounced in the 80at% Mg system and disappears at elevated temperatures. The density, self-diffusion coefficient, and shear viscosity for the Mg-La liquid alloy were predicted via DPMD simulation, the evolution patterns with Mg content and temperature were subsequently discussed, and a database was established accordingly. Finally, the mixing enthalpy and elemental activity of the Mg-La liquid alloy at 1200 K were reliably evaluated,which provides new guidance for related studies.

关键词： magnesium-lanthanum liquid alloys local structure macroscopic properties thermodynamic behavior deep potential mo-lecular dynamic simulation

基于神经网络的电力系统暂态稳定分布式自适应控制

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控制与决策 2021年第6期36卷 1407-1414页

作者：陈世明卢家胜高彦丽华东交通大学电气与自动化工程学院南昌330013

针对电力系统中普遍存在的系统非线性和参数不确定性等问题,提出一种基于径向基函数神经网络(RBFNN)的分布式自适应控制器,以提高多机电力系统的暂态稳定性.利用基于RBFNN的方法对系统中的未知非线性项和外部扰动进行补偿,设计相应的自... 详细信息

针对电力系统中普遍存在的系统非线性和参数不确定性等问题,提出一种基于径向基函数神经网络(RBFNN)的分布式自适应控制器,以提高多机电力系统的暂态稳定性.利用基于RBFNN的方法对系统中的未知非线性项和外部扰动进行补偿,设计相应的自适应参数估计方法,逼近未知非线性项的理想权值矩阵.该策略基于多智能体框架,分布式控制器通过通信网络接收测量装置测量的实时数据,并控制储能装置动作,使受到扰动后各发电机能够迅速实现频率同步.利用李雅普诺夫稳定性理论,证明所提出的分布式控制方法的收敛性.最后,通过仿真研究验证所提出的分布式控制方法的有效性.

关键词：神经网络电力系统暂态稳定分布式控制自适应估计多智能体框架储能装置

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原位置换法稳定导电胶接触电阻的研究

功能材料 2011年第3期42卷 528-532,536页

作者：高宏刘岚卢嘉圣罗远芳贾德民刘孔华华南理工大学材料科学与工程学院广东广州510640

研究两种水溶性银盐(硝酸银及乙酸银)对银填充导电胶的热行为和体积电阻率的影响,及湿热老化条件下在锡表面接触电阻的稳定作用。DSC测试结果表明,这两种银盐的引入对导电胶固化行为没有影响。导电胶在湿热老化600h后,添加了2%(质量分数... 详细信息

研究两种水溶性银盐(硝酸银及乙酸银)对银填充导电胶的热行为和体积电阻率的影响,及湿热老化条件下在锡表面接触电阻的稳定作用。DSC测试结果表明,这两种银盐的引入对导电胶固化行为没有影响。导电胶在湿热老化600h后,添加了2%(质量分数)的硝酸银和1.5%(质量分数)乙酸银样品体积电阻率分别下降了48.5%和47.4%,而空白样仅降低了27.3%。另外当硝酸银添加量≥1%(质量分数)或乙酸银≥0.5%(质量分数)时,经湿热老化后导电胶在锡表面的接触电阻非常稳定。XRD、XPS和SEM结果表明银盐经过湿热老化后在锡面发生原位置换,在导电胶/锡界面形成一层致密的银层,可以消除与导电填料银粉的电位差,阻止了电化学腐蚀从而达到稳定接触电阻的效果。

关键词：导电胶接触电阻水溶性银盐原位置换电化学腐蚀

天广直流系统天生桥站408316换流变压器故障分析

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变压器 2008年第6期45卷 69-73页

作者：曾宪刚吕家圣中国南方电网超高压输电公司天生桥局贵州兴义562400

对天广直流系统天生桥站408316换流变压器故障进行了分析。

关键词：换流变压器色谱分析故障

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关于我国民办教育产业发展的几个问题

黄河科技大学学报 2003年第2期5卷 18-21页

作者：鲁加升厦门南洋学院福建厦门361009

民办教育在我国已形成了一个新兴的产业之一,但还面临着一些困难和问题。政府和社会舆论应给予更多支持,对教育拔款贷款制度应进行重大改革,并完善民办教育产业的立法,促进民办教育发展。

关键词：民办教育产业发展

Passive activity enhances residual control ability in patients with complete spinal cord injury

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Neural Regeneration Research 2025年第8期20卷 2337-2347页

作者： Yanqing Xiao Mingming Gao Zejia He jia Zheng Hongming Bai jia-sheng Rao Guiyun Song Wei Song Xiaoguang Li Beijing Key Laboratory for Biomaterials and Neural Regeneration Beijing Advanced Innovation Center for Biomedical EngineeringSchool of Biological Science and Medical EngineeringBeihang UniversityBeijingChina Department of Rehabilitation Evaluation China Rehabilitation Research CenterBeijingChina Cardiac Center Beijing Children’s HospitalCapital Medical UniversityBeijingChina The State Key Laboratory of Virtual Reality Technology and Systems Beihang UniversityBeijingChina Department of Rehabilitation Engineering China Rehabilitation Science InstituteBeijingChina

Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury ***,because of prolonged inactivity,initial attempts to activate these muscles may not effectively engage any of the remaining neurons in the descending pathway.A previous study unexpectedly found that a brief clinical round of passive activity significantly increased volitional muscle activation,as measured by surface *** this study,we further explored the effect of passive activity on surface electromyographic signals during volitional control tasks among individuals with complete spinal cord *** patients with chronic complete thoracic spinal cord injury were *** electromyography data from eight major leg muscles were acquired and compared before and after the passive activity *** results indicated that the passive activity led to an increased number of activated volitional muscles and an increased frequency of *** the cumulative root mean square of surface electromyography amplitude for volitional control of movement showed a slight increase after passive activity,the difference was not statistically *** findings suggest that brief passive activity may enhance the ability to initiate volitional muscle activity during surface electromyography tasks and underscore the potential of passive activity for improving residual motor control among patients with motor complete spinal cord injury.

关键词： complete spinal cord injury cycle training epidural electrical stimulation motor training passive activity physiological state spinal cord circuit surface electromyography volitional control task