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Vortex-lines motion for the Ginzburg-Landau equation with impurity

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Science China Mathematics 2007年第12期50卷 1705-1734页

作者： zu-han LIU Department of Mathematics Xuzhou Normal University Xuzhou 221116 China

In this paper, we study the asymptotic behavior of solutions of the Ginzburg-Landau equation with impurity. We prove that, asymptotically, the vortex-lines evolve according to the mean curvature flow with a forcing te... 详细信息

关键词： mean curvature flow, vortices, geometric measure theory, Ginzburg-Landau equations

Energy Estimate for the Type-Ⅱ Superconducting Film

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Acta Mathematica Sinica,English Series 2008年第1期24卷 75-86页

作者： Kwang Ik KIM zu han LIU Department of Mathematics Pohang University of Science and Technology Pohang 790-784 Republic of Korea Department of Mathematics Xuzhou Normal University Xuzhou 221116 P. R. China

We study the minimizers of the Ginzburg-Landau model for variable thickness, superconducting, thin films with high k, placed in an applied magnetic field hex, when hex is of the order of the ＂first critical field＂, i.e. of the order of ｜lnε｜. We obtain the asymptotic estimates of minimal energy and describe the possible locations of the vortices.

关键词： superconductivity Ginzburg-Landau functional free boundary problem

An Empirical Investigation on the Risk-Return Relationship of Carbon Future Market

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Journal of Systems Science & Complexity 2016年第4期29卷 1057-1070页

作者： LI Ziran QIAO han SONG Nan zu Lei Collaborative Innovation Center for the Innovation and Regulation of Internet-Based Finance Southwestern University of Finance and EconomicsChengdu 611130China CFFEX Institute for Financial Derivatives Beijing 100033China School of Management University of Chinese Academy of SciencesBeijing 100190China Directors'Office Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Management Sciences and Engineering Central University of Finance and EconomicsBeijing 100081China

This paper examines the risk-return relationship for the carbon future market during Phases I, II and III of the European Union Emission Trading Scheme(EU ETS). The risk factors derived from the newly developed LSW model, are embedded into a GARCH framework. This new specification is compared with several GARCH-M type models analyzing the risk-return relationship in the carbon market. The results show that the new specification consistently achieves a good fit and possesses superior explanatory power for the European Union Allowance(EUA) data. Some policy suggestions regarding market efficiency are also provided.

关键词： Carbon price GARCH information diffusion risk-return.

Uniqueness and Least Energy Property for Solutions to a Strongly Coupled Elliptic System

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Acta Mathematica Sinica,English Series 2017年第3期33卷 419-438页

作者： Shan ZhanG Ling ZHOU zu han LIU Department of Applied Mathematics Nanjing University of Finance & Economics Nanjing 210003 P. R. China School of Mathematical Science Yangzhou University Yangzhou 225002 P. R. China

For the strongly coupled system of M ≥ 3 competing species：-△[（di＋∑j=1^Mβijuj）ui]=（ai-bi）ui-kui∑j≠iui,i=1,…,M,we prove the uniqueness of the limiting configuration as k →∞ under suitable conditions. Moreover, we prove that the limiting configuration minimizes a variational problem associated to the strongly coupled system among the segregated states with the same boundary conditions.

关键词： Strongly coupled elliptic system uniqueness spatial segregation

Decomposition and Products of Wheat and Rice Straw from a FACE Experiment Under Flooded Conditions

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Pedosphere 2009年第3期19卷 389-397页

作者： LIU Juan han Yong CAI zu-Cong State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 （China） Graduate University of the Chinese Academy of Sciences Beijing 100049 （China） School of Environmental Science and Technology Zhejiang Forestry University Lin＇an Hangzhou 311300 （China）

Winter wheat and rice straw produced under ambient and elevated CO2 in a China rice-wheat rotation free-air CO2 enrichment （FACE） experiment was mixed with a paddy soil at a rate of 10 g kg^-1 （air-dried）, and the mixture was incubated under flooded conditions at 25℃ to examine the differences in decomposition as well as the products of crop residues produced under elevated CO2. Results showed that the C/N ratio and the amount of soluble fraction in the amended rice straw grown under elevated CO2 （FR） were 9.8% and 73.1% greater, and the cellulose and lignin were 16.0% and 9.9% lesser than those of the amended rice straw grown under ambient CO2 （AR）, respectively. Compared with those of the AR treatment, the CO2-C and CH4-C emissions in the FR treatment for 25 d were increased by 7.9% and 25.0%, respectively; a higher ratio of CH4 to CO2 emissions induced by straw in the FR treatment was also observed. In contrast, in the treatments with winter wheat straw, the CO2-C and CH4-C emissions, the ratio of straw-induced CH4 to CO2 emissions, and the straw composition were not significantly affected by elevated CO2, except for an 8.0% decrease in total N and a 9.7% increase in C/N ratio in the wheat straw grown under elevated CO2. Correlation analysis showed that the net CO2-C and CH4-C emission from straw and the ratio of straw-induced CH4 to CO2 emissions were all exponentially related to the amount of soluble fraction in the amended straw （P 〈0.05）. These indicated that under flooded conditions, the turnover and CH4 emission from crop straw incorporated into soil were dependent on the effect of elevated CO2 on straw composition, and varied with crop species. Incorporation of rice straw grown under elevated CO2 would stimulate CH4 emission from flooded rice fields, whereas winter wheat straw grown under elevated CO2 had no effect on CH4 emission.

关键词： carbon cycle CH4 CO2 emissions soluble fraction

Micromechanical mode-localized electric current sensor

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Microsystems & Nanoengineering 2022年第2期8卷 49-58页

作者： han Li Zhao Zhang Luhan zu Yongcun Hao Honglong Chang Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace School of Mechanical EngineeringNorthwestern Polytechnical University127 Youyi West RoadBeilin DistrictXi'an 710072China

This paper outlines the design of a novel mode-localized electric current sensor based on a mechanically sensitive element of weakly coupled resonator *** the advantage of a high voltage sensitivity of weakly coupled resonator systems,the current under test is converted to voltage via a silicon shunt resistor,which causes stiffness perturbation to one *** mode-localization phenomenon alters the energy distribution in the weakly coupled resonator system.A theoretical model of current sensing is established,and the performance of the current sensor is determined:the sensitivity of the electric current sensor is 567/A,the noise floor is 69.3 nAA/Hz,the resolution is 183.6 nA,and the bias instability is 81.6 *** mode-localized electric current sensor provides a new approach for measuring sub-microampere currents for applications in nuclear physics,including for photocurrent signals and transistor leakage *** could also become a key component of a portable mode-localized multimeter when combined with a mode-localized *** addition,it has the potential for use in studying sensor arrays to achieve higher resolution.

关键词： mode weakly resonator

A closed-loop particle swarm optimizer for multivariable process controller design

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第8期9卷 1050-1060页

作者： Kai han Jun ZHAO zu-hua XU Ji-xin QIAN State Key Lab of Industrial Control Technology Institute of Industrial Process Control Zhejiang University Hangzhou 310027 China

Design of general multivariable process controllers is an attractive and practical alternative to optimizing design by evolutionary algorithms (EAs) since it can be formulated as an optimization problem. A closed-loop particle swarm optimization (CLPSO) algorithm is proposed by mapping PSO elements into the closed-loop system based on control theories. At each time step, a proportional integral (PI) controller is used to calculate an updated inertia weight for each particle in swarms from its last fitness. With this modification, limitations caused by a uniform inertia weight for the whole population are avoided, and the particles have enough diversity. After the effectiveness, efficiency and robustness are tested by benchmark functions, CLPSO is applied to design a multivariable proportional-integral-derivative (PID) controller for a solvent dehydration tower in a chemical plant and has improved its performances.

关键词： Multivariable process control Proportional-integral-derivative (PID) control Model predictive control (MPC) Particle swarm optimization (PSO) Closed-loop system

Lymph node metastasis and lymphadenectomy of resectable adenocarcinoma of the esophagogastric junction

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Chinese Journal of Cancer Research 2014年第3期26卷 237-242页

作者： Xin-zu Chen Wei-han Zhang Jian-Kun Hu Department of Gastrointestinal Surgery West China HospitalSichuan University

Based on Siewert classification, adenocarcinomas of the esophagogastric junction （AEGs） have different behaviors of perigastric-mediastinal nodal metastasis. Siewert type I AEGs have higher incidence of mediastinal nodal metastasis than those of type H or III, especially at middle-upper mediastinum. With regard to the necessity of mediastinal lymphadenectomy, theoretically, transthoracic esophagogastrectomy with complete mediastinal lymphadenectomy is suggested for Siewert type I AEGs, while transhiatal total gastrectomy with lower mediastinal and D2 perigastric lymphadenectomy is a standard surgery for type II-III AEGs. Nevertheless, the mediastinal nodal metastasis is an independent factor of poor prognosis for any type of AEG.

关键词： Adenocarcinomas of the esophagogastric junction (AEGs) surgery lymph node metastasis lymphadenectomy

Arsenite oxidation by three types of manganese oxides

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Journal of Environmental Sciences 2006年第2期18卷 292-298页

作者： FENG Xiong-han zu Yan-qun TAN Wen-feng LIU Fan College of Resources and Environment Huazhong Agricultural University Wuhan 430070 China College of Resources and Environment Yunnan Agricultural University Kunming 650201 China

Oxidation of As（Ⅲ） by three types of manganese oxides and the effects ofpH, ion strength and tartaric acid on the oxidation were investigated by means of chemical analysis, equilibrium redox, X-ray diffraction （XRD） and transmission electron microscopy （TEM）. Three synthesized Mn oxide minerals, bimessite, cryptomelane, and hausmannite, which widely occur in soil and sediments, could actively oxidize As（Ⅲ） to As（Ⅴ）. However, their ability in As（Ⅲ）-oxidation varied greatly depending on their structure, composition and surface properties. Tunnel structured cryptomelane exhibited the highest ability of As （Ⅲ） oxidation, followed by the layer structured birnessite and the lower oxide hausmannite. The maximum amount of As （Ⅴ） produced by the oxidation was in the order （mmol/kg） of cryptomelane （824.2）〉 bimessite （480.4）〉 hausmannite （117.9）, As pH increased from the very low value（pH 2.5）, the amount of As（Ⅲ） oxidized by the tested Mn oxides was firstly decreased, then negatively peaked in pH 3.0 6.5, and eventually increased remarkably. Oxidation of As（Ⅲ） by the Mn oxides had a buffering effects on the pH variation in the solution. It is proposed that the oxidative reaction processes between As （Ⅲ） and biruessite（or cryptomelane） are as follows：（1） at lower pH condition：（MnO2）x＋ H3AsO3 ＋ 0.5H^＋=0.5H2AsO4^- ＋ 0.5HAsO4^2- ＋Mn〉^2＋（MnO2）x-1 ＋ H2O; （2） at higher pH condition：（MnO2）x ＋ H3AsO3 = 0.5H2AsO4^- ＋ 0.5HAsO4^2- ＋ 1.5H^＋＋（MnO2）x-1. MnO. With increase of ion strength, the As（Ⅲ） oxidized by bimessite and cryptomelane decreased and was negatively correlated with ion strength. However, ion strength had little influence on As （Ⅲ） oxidation by the hausmarmite. The presence of tartaric acid promoted oxidation of As（Ⅲ） by birnessite. As for cryptomelane and hansmannite, the same effect was observed when the concentration of tartaric acid was below 4 mmol/L, otherwise the oxidized As（Ⅲ） decreased. These findings are of great significance in improving our understanding

关键词： oxidation of As(Ⅲ) As(Ⅴ) Mn oxides pH ion strength tartaric acid