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Hamilton-Souplet-Zhang's gradient estimates for two weighted nonlinear parabolic equations

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Applied mathematics(A Journal of Chinese Universities) 2017年第3期32卷 353-364页

作者： ma bing-qing HUANG Guang-yue Department of mathematics Henan Normal University Xinxiang 453007 China

In this paper, we consider gradient estimates for positive solutions to the following weighted nonlinear parabolic equations on a complete smooth metric measure space with only Bakry-Émery Ricci tensor bounded below: One is $${u_t} = {\Delta _f}u + au\log u + bu$$ with a, b two real constants, and another is $${u_t} = {\Delta _f}u + \lambda {u^\alpha }$$ with λ, α two real constants. We obtain local Hamilton-Souplet-Zhang type gradient estimates for the above two nonlinear parabolic equations. In particular, our estimates do not depend on any assumption on f.

关键词： Hamilton’s gradient estimate Souplet-Zhang’s gradient estimate weighted nonlinear parabolic equation Bakry-Émery Ricci tensor

MULTI-GRANULARITY EVOLUTION ANALYSIS OF SOFTWARE USING COMPLEX NETWORK THEORY

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Journal of Systems Science & Complexity 2011年第6期24卷 1068-1082页

作者： Weifeng PAN bing LI Yutao ma Jing LIU State Key Laboratory of Software Engineering Wuhan University Wuhan 430072 China School of Computer Science and Information Engineering Zhejiang Gongshang University Hangzhou 310018 China School of Computer Wuhan University Wuhan 430072 China Complex Networks Research Center Wuhan University Wuhan 430072 China

Software systems are a typical kind of man-made complex systems. Understanding their evolutions can lead to better software engineering practices. In this paper, the authors use complex network theory as a tool to analyze the evolution of object-oriented （OO） software from a multi-granularity perspective. First, a multi-granularity software networks model is proposed to represent the topological structures of a multi-version software system from three levels of granularity. Then, some parameters widely used in complex network theory are applied to characterize the software networks. By tracing the parameters＇ values in consecutive software systems, we have a better understanding about software evolution. A case study is conducted on an open source OO project, Azureus, as an example to illustrate our approach, and some underlying evolution characteristics are uncovered. These results provide a different dimension to our understanding of software evolutions and also are very useful for the design and development of OO software systems.

关键词： Complex networks multi-granularity software evolution software system.

Super-resolution image reconstruction based on three-step-training neural networks

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Journal of Systems Engineering and Electronics 2010年第6期21卷 934-940页

作者： Fuzhen Zhu Jinzong Li bing Zhu Dongdong ma Institute of Image Information Technology and Engineering Harbin Institute of Technology Heilongjiang 150001 R R. China

A new method of super-resolution image reconstruction is proposed, which uses a three-step-training error backpropagation neural network （BPNN） to realize the super-resolution reconstruction （SRR） of satellite image. The method is based on BPNN. First, three groups learning samples with different resolutions are obtained according to image observation model, and then vector mappings are respectively used to those three group learning samples to speed up the convergence of BPNN, at last, three times consecutive training are carried on the BPNN. Training samples used in each step are of higher resolution than those used in the previous steps, so the increasing weights store a great amount of information for SRR, and network performance and generalization ability are improved greatly. Simulation and generalization tests are carried on the well-trained three-step-training NN respectively, and the reconstruction results with higher resolution images verify the effectiveness and validity of this method.

关键词： image reconstruction super-resolution three-steptraining neural network BP algorithm vector mapping.

Socioeconomic Status and Obesity Gradient over Age： New Evidence from China

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2012年第1期7卷 70-93页

作者： bing ma Department of Economics University of Maryland Baltimore County Baltimore MD 21250USA

This paper presents a systematic analysis of the impact of socioeconomic status （SES） on overweight and obesity in China and investigates how and why the SES-obesity gradient differs with age. Using a longitudinal sample drawn from the China Health and Nutrition Survey （CHNS）, I find that body mass index （BMI） is positively associated with SES during early childhood but becomes inversely related to childhood SES as children age into adulthood. Estimation results show that children from low SES families are less likely to be overweight or obese than their median and high SES peers. The results from subsamples stratified by living area reveal that the SES gaps of obesity are generally larger for urban residents than rural residents. Females are significantly less likely to be overweight than males in China. The SES during childhood has independent effects after controlling for respondents＇ contemporaneous SES. The relationship between the contemporaneous SES of a male adult and his chance of being overweight or obese is significantly positive, while the contemporaneous SES of a female adult is negatively related to her chance of being overweight or obese.

关键词： body weight BMI overweight obesity socioeconomic status,China

Error analysis on heading determination via genetic algorithms

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Journal of Systems Engineering and Electronics 2006年第3期17卷 673-676页

作者： Zhong bing Xu Jiangning ma Heng Dept. of Electric Naval Univ. of Engineering Wuhan 430033 P. R. China

A new error analysis method is presented via genetic algorithms for high precise heading determination model based on two total positioning stations （TPSs）. The method has the ability to search all possible solution space by the genetic operators of elitist model and restriction. The result of analyzing the error of this model shows that the accuracy of this model is precise enough to meet the need of calibration for navigation systems on ship, and the search space is only 0. 03% of the total search space, and the precision of heading determination is 4＂ in a general dock.

关键词： heading determination SGA genetic algorithms.

COMPUTATIONAL FLOW RATE FEEDBACK AND CONTROL METHOD IN HYDRAULIC ELEVATORS

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Chinese Journal of Mechanical Engineering 2005年第4期18卷 490-493页

作者： Xu bing ma Jien Lin Jianjie State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

The computational flow rate feedback and control method, which can be used in proportional valve controlled hydraulic elevators, is discussed and analyzed. In a hydraulic elevator with this method, microprocessor receives pressure information from the pressure transducers and computes the flow rate through the proportional valve based on pressure-flow conversion real time algorithm. This hydraulic elevator is of lower cost and energy consumption than the conventional closed loop control hydraulic elevator whose flow rate is measured by a flow meter. Experiments arc carried out on a test rig which could simulate the load of hydraulic elevator. According to the experiment results, the means to modify the pressure-flow conversion algorithm are pointed out.

关键词： Hydraulic elevator Computational flow rate Proportional valve

Synthesis of a New Type of Amphilic and Water - soluble Tertiary Phosphine Ligands Substituted by an Ethoxylated Phosphonic Acid Chain and Their Palladium Complexes

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Chinese Chemical Letters 2002年第9期13卷 839-842页

作者： Xiang Kai FU Xue bing ma College of Chemistry and Chemical Engineering Southwest-China Normal UniversityChongqing 400715

The highly water-soluble phosphine ligands Na2O3PCH2CH2NH(CH2CH2O)nCH2CH2N- (CH2PPh2)2 (n=1,2,3) were prepared by a new and simple route under mild conditions in good yield; the palladium (II) complexes of the ligands... 详细信息

关键词： Water-soluble diphenylphosphinomethyl phosphine ligands palladium complexes synthesis.

Flow patterns and dissipation of turbulent kinetic energy in near-wall turbulence

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Chinese Science Bulletin 1998年第2期43卷 117-120页

作者： Zhaoshun Zhang bing ma Guixiang Cui Chunxiao Xu Tsing Hua Univ Dept Engn Mech Beijing 100084 Peoples R China

It is disclosed the flow patterns of turbulent flows in near wall region by means of topological analysis. It has found that there exists a close relationship between the topological characteristics and the spikes which are dominated by the strong normal velocity fluctuations near the wall. It is also shown that the dissipation of turbulent kinetic energy is closely related to the spike events.

关键词： wall turbulence dissipation of turbulent kinetic energy topological analysis of flows.

Thiourea functionalized CdSe/CdS quantum dots as a fluorescent sensor for mercury ion detection

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Chinese Chemical Letters 2016年第9期27卷 1531-1536页

作者： Li-Li Xi Hong-bing ma Guan-Hong Tao College of Chemistry Chemical Engineering and Materials Science Soochow University Analytical and Testing Center Soochow University

CdSe/CdS quantum dots （QDs） functionalized by thiourea （TU） were synthesized and used as a fluorescent sensor for mercury ion detection. The TU-functionalized QDs were prepared by bonding TU via electrostatic interaction to the core/shell CdSe/CdS QDs after capping with thioglycolic acid （TGA）. It was observed that the fluorescence of the functionalized QDs was quenched upon the addition of Hg^2＋. The quantitative detection of Hg^2＋ with this fluorescent sensor could be conducted based on the linear relationship between the extent of quenching and the concentration of Hg^2＋ added in the range of 1-300 μg.L^-1, A detection limit of 0.56 μg.L^-1 was achieved. The sensor showed superior selectivity for Hg^2＋ and was successfully applied to the determination of mercury in environmental samples with satisfactory results

关键词： Quantum dots Fluorescent sensor Thiourea Quenching Mercury ion Detection