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Synthesis,Characterization and Standard Molar Formation Enthalpy of [Sm(C_7H_5O_3)_2(C_4H_6NO_2S)]·2H_2O

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Chemical Research in Chinese Universities 2009年第4期25卷 564-568页

作者： LI Xu YANG De-jun LI Qiang-guo LI Ai-tao YE Li-juan JIANG Jian-hong Department of Chemistry and Life Science Xiangnan University Chenzhou 423000 P. R. China

[Sm（C7H5O3）2（C4H6NO2S）]·2H2O was synthesized from the reaction of samarium chloride hexahydrate with salicylic acid and thioproline,and characterized by IR,elemental analysis and thermogravimatric *** standard molar enthalpies of the solutions of SmCl3·6H2O（s）,2[C7H6O3（s）],[C4H7NO2S（s）] and [Sm（C7H5O3）2·（C4H6NO2S）·2H2O（s）] in a mixed solvent of absolute ethyl alcohol,dimethyl formamide（DMF） and 3 mol/L HCl were,respectively,determined by calorimetry to be ΔsHm^Θ [SmCl3·6H2O（s）,298.15 K]=（-46.68±0.15） kJ/mol,ΔsHm^Θ [2C7H6O3（s）,298.15 K]=（25.19±0.02） kJ/mol,ΔsHm^Θ [C4H7NO2S（s）,298.15 K]=（16.20±0.17） kJ/mol and ΔsHm^Θ {[Sm（C7H5O3）2（C4H6NO2S）]·2H2O（s）,298.15 K}=（-81.24±0.67） kJ/*** enthalpy change of the reaction SmCl3·6H2O（s）＋2C7H6O3（s）＋C4H7NO2S（s）=[Sm（C7H5O3）2（C4H6NO2S）]·2H2O（s）＋3HCl（g）＋4H2O（l） was determined to be ΔrHm^Θ =（123.45±0.71） kJ/*** the data in the literature,the standard molar formation enthalpy of [Sm（C7H5O3）2（C4H6NO2S）]·2H2O（s） was estimated to be Δf Hm^Θ {[Sm（C7H5O3）2（C4H6NO2S）]·2H2O（s）,298.15 K}=（-2912.03±3.1） kJ/mol through Hess＇ law.

关键词： Samarium chloride hexahydrate Salicylic acid Thioproline Standard molar formation enthalpy

Information diffusion on adaptive network

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Chinese Physics B 2008年第10期17卷 3536-3541页

作者：胡柯唐翌 Department of Physics and Institute of Modern Physics Xiangtan University

Based on the adaptive network, the feedback mechanism and interplay between the network topology and the diffusive process of information are studied. The results reveal that the adaptation of network topology can drive systems into the scale-free one with the assortative or disassortative degree correlations, and the hierarchical clustering. Meanwhile, the processes of the information diffusion are extremely speeded up by the adaptive changes of network topology.

关键词： adaptive network information diffusion degree correlation hierarchical clustering

Periodic Solution to BAM-type Cohen-Grossberg Neural Network with Time-varying Delays

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Acta Mathematicae Applicatae Sinica 2011年第3期27卷 427-442页

作者： An-ping Chen Qun-hua Gu Department of Mathematics Xiangnan University Chenzhou Hunan 423000 China School of Mathematics and Computational Science Xiangtan University Xiangtan Hunan 411005 China

By using the continuation theorem of Mawhin＇s coincidence degree theory and the Liapunov func tional method, some sufficient conditions are obtained to ensure the existence, uniqueness and the global exponential stab... 详细信息

关键词： periodic solution time-varying delays global exponential stability BAM-type Cohen-Grossberg neural network coincidence degree theory

Electroless Ni-Co-P Coating of Cenospheres Using Ag(NH_(3))_(2)^(+) Activator

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材料热处理学报 2004年第05B期25卷 1115-1118页

作者： ZENGAi-xiang XIONGWei-hao DepartmentofChemistry ChangshaUniversityofScienceandTechnologyChangshaChina／／StateKayLaboratoryofDie＆MouldTechnologyHuazhongUniversityofScienceandTechnologyWuhanChina StateKayLaboratoryofDie＆MouldTechnology HuazhongUniversityofScienceandTechnologyWuhanChina

Electroless Ni-Co-P-coating of fly-ash cenosphere particles is demonstrated in the present investigation. The Electroless Ni-Co-P-coating process is modified by replacing the conventional sensitization and activation steps with only using activation step with Ag(NH3)2+ activator. The cenospheres are characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS) during and after the coating process. Relatively uniform coating is obtained under the given coating conditions. The possible mechanism of electroless Ni-Co-P-coating of cenospheres utilizing Ag(NH3)2+ activator is suggested. The low density Ni-Co-P coated cenospheres may be utilized for manufacturing conducting polymers for EMI-shielding application and microwave absorbing materials.

关键词： Ni-Co-P涂层 Ag(NH3)2^+活化剂飞灰微粒非电解镀层

CONTROLLABILITY FOR A PARABOLIC EQUATION WITH A NONLINEAR TERM INVOLVING THE STATE AND THE GRADIENT

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Acta Mathematica Scientia 2010年第5期30卷 1593-1604页

作者：许友军刘振海 School of Mathematics and Physics University of South China School of Mathematical Sciences and Computing Technology Central South University

In this article, we consider the controllability of a quasi-linear heat equation involving gradient terms with Dirichlet boundary conditions in a bounded domain of *** results are established by using the variational ... 详细信息

关键词： controllability Kakutani fixed-point theorem nonlinear gradient term

Dark soliton in one-dimensional Bose-Einstein condensate under a periodic perturbation of trap

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Chinese Physics B 2011年第1期20卷 150-156页

作者：刘超飞胡柯胡涛唐翌 Department of Physics Xiangtan University

The perturbation of a confining trap leads to the collective oscillation of a Bose-Einstein condensate, thereby the propagation of a dark soliton in the condensate is affected. In this study, periodic perturbation is employed to match the soliton oscillation. We find that the soliton dynamics depends sensitively on the coupling between the moving direction of the trap and that of the soliton. The soliton energy/depth evolves periodically, and a relevant shift in the soliton trajectory occurs as compared with the unperturbed case. Overall, the soliton oscillation frequency changes little even if the perturbation amplitude and frequency vary.

关键词： Bose-Einstein condensate dark soliton

Model for cascading failures with adaptive defense in complex networks

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Chinese Physics B 2010年第8期19卷 65-71页

作者：胡柯胡涛唐翌 Department of Physics and Institute of Modern Physics Xiangtan University

This paper investigates cascading failures in networks by considering interplay between the flow dynamic and the network topology, where the fluxes exchanged between a pair of nodes can be adaptively adjusted depending on the changes of the shortest path lengths between them. The simulations on both an artificially created scale-free network and the real network structure of the power grid reveal that the adaptive adjustment of the fluxes can drastically enhance the robustness of complex networks against cascading failures. Particularly, there exists an optimal region where the propagation of the cascade is significantly suppressed and the fluxes supported by the network are maximal. With this understanding, a costless strategy of defense for preventing cascade breakdown is proposed. It is shown to be more effective for suppressing the propagation of the cascade than the recent proposed strategy of defense based on the intentional removal of nodes.

关键词： cascading failure adaptive defense complex network

A POSTERIORI ERROR ANALYSIS FOR A FULLY DISCRETE DISCONTINUOUS GALERKIN APPROXIMATION TO A KIND OF REACTIVE TRANSPORT PROBLEMS

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Journal of Systems Science & Complexity 2012年第2期25卷 398-409页

作者： Jiming YANG Yanping CHEN College of Science Hunan Institute of Engineering School of Mathematical Sciences South China Normal University

In order to obtain an expected numerical solution, a fully discrete discontinuous Galerkin method is applied to a kind of reactive transport problems in two dimension. That is to say, the space variable is discretized with the symmetric interior penalty Calerkin method （SIPG）, and the time variable is done with the backward Euler method. Making use of the duality technique, hp approximation properties and the interpolation theory, a residual-type a posteriori error estimation is achieved, which can be used for adaptivity. Compared with the analyses of semi-discretization, the current presentation is more challenging and more significant.

关键词： A posteriori error discontinuous Galerkin duality technique full discretization reactivetransport.

Course Drop-out Prediction on MOOC Platform via Clustering and Tensor Completion

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Tsinghua Science and Technology 2019年第4期24卷 412-422页

作者： Jinzhi Liao Jiuyang Tang Xiang Zhao National University of Defense Technology

As a supplement to traditional education, online courses offer people, regardless of their age, gender, or profession, the chance to access state-of-the-art knowledge. Nonetheless, despite the large number of students who choose to begin online courses, it is easy to observe that quite a few of them drop out in the middle, and information on this is vital for course organizers to improve their curriculum outlines. In this work, in order to make a precise prediction of the drop-out rate, we propose a combined method MOOP, which consists of a global tensor and local tensor to express all available feature aspects. Specifically, the global tensor structure is proposed to model the data of the online courses, while a local tensor is clustered to capture the inner connection of courses. Consequently, drop-out prediction is achieved by adopting a high-accuracy low-rank tensor completion method, equipped with a pigeon-inspired algorithm to optimize the parameters. The proposed method is empirically evaluated on real-world Massive Open Online Courses(MOOC) data, and is demonstrated to offer remarkable superiority over alternatives in terms of efficiency and accuracy.

关键词： MOOC platform drop-out prediction tensor completion clustering