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β-Sialon Produced by Carbon Thermal Nitriding Reaction of Bauxite

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International Journal of Minerals,Metallurgy and Materials 2000年第3期14卷 209-213页

作者： Jun Wang, Nan Li, Caicheng Shi, Chengchang Jia ( Material science and Engineering School, university of science and technology Beijing, Beijing 100083, China Material science and Engineering School, wuhan university of science and technology, wuhan 430 Material science and Engineering School University of Science and Technology Beijing Beijing 100083 China Material science and Engineering School Wuhan University of Science and Technology Wuhan 430081 China

β-Sialon was produced by carbon thermal nitriding reaction in N_2 gas atmosphere when the mixtures of bauxite and anthracite were put into vertical furnace. According to the mass loss of raw materials and the result of X-ray diffration (XRD) of products, the influences of the process parameters on the compositions and relative contents of products, such as the fixed carbon content, the flow of N2, the soaking time and the temperature, were researched.

关键词： β-Sialon bauxite anthracite carbon thermal nitriding processing parameter vertical furnace

Partial Oscillation of m-dimensional Logistic Ecologic Models

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wuhan university Journal of Natural sciences 1998年第1期3卷 5-10页

作者： Luo Qi(Department of Basic science, wuhan Yejin university of science and technology, wuhan 430081, China) wuhan Yejin university of science and technology Department of Basic Science Wuhan China (GRID:grid.412787.f) (ISNI:***)

We present and discuss the partial oscillation with respect to equilibrium state ofm-dimensional Logistic delay ecologic models, and obtain some simple criteria.

关键词： Logistic ecologic model partial oscillation diffusion constant Liapunov functional

Refrigerant Control Strategies for Residential Air-Conditioning and Heat-Pump System

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湖南大学学报（自然科学版） 2009年第S1期36卷 91-95页

作者： SU Shun-yu,ZHANG Chun-zhi,CHEN Jian(College of Urban Construction,wuhan university of science and technology,wuhan,Hubei 430070,China) College of Urban Construction Wuhan University of Science and Technology Wuhan 430070 China

This paper simulated the optimal refrigerant charge inventory of a refrigeration system in air-conditioning operation and heat-pump operation respectively,and studied the refrigerant control strategies in this *** void fraction in two-phase fluid region was calculated by Harms *** based on distributed parameter model and Harms model,the refrigerant charge inventory in condenser and evaporator were calculated and analyzed in air-conditioning conditions and heat-pump conditions,*** calculating results of different refrigerant mass between refrigeration and heating conditions indicate that the optimal refrigerant charge inventory in heat-pump conditions is lower than that in air-conditioning *** avoid the decrease of COP due to the surplus refrigerant in heating conditions,we introduced the liquid reservoir control method and associate capillary control *** of them could increase the heating capacity of the air-source heat *** difference of optimal refrigerant charge inventory in air-conditioning and heat-pump system can be controlled by the liquid reservoir or the associate capillary.

关键词： air-source heat pump control strategy distributed parameter model charge inventory

SEPARATION PROPERTY OF POSITIVE RADIAL SOLUTIONS FOR A GENERAL SEMILINEAR ELLIPTIC EQUATION

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Acta Mathematica Scientia 2011年第1期31卷 181-193页

作者：杨芬张丹丹 College of science Wuhan University of Science and Technology Department of Mathematics Xiangfan University

The asymptotic behavior at infinity and an estimate of positive radial solutions of the equation △u ＋ sum from i=1 to k cirli upi = 0, x ∈ Rn,（0.1）are obtained and the structure of separation property of positive... 详细信息

关键词： Asymptotic behavior separation property semilinear elliptic equation

Study on Kinetic Model for Dephosphorization of High-Phosphorus Hot Metal Pretreatment

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Journal of Iron and Steel Research International 2011年第S2期18卷 113-118页

作者： YANG Fu, BI Xue-gong (Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,wuhan university of science and technology, wuhan 430081, Hubei, China) wuhan Univ Sci & Technol Key Lab Ferrous Met & Resources Utilizat Minist Educ Wuhan 430081 Peoples R China

Focused on the hot metal pretreatment process in the torpedo-car and based on the powder injection metallurgy principle, a kinetic model for dephosphorization of high-phosphorus hot metal pretreatment was developed. The validity of this model was verified by comparison between the experimental results in laboratory and the calculated results. The influences of dephosphorization capacity of molten slag and technological conditions on the dephosphorization efficiency were calculated by applying the model. The results show that lower temperatures are favorable to dephosphorization, CaO content in slag should be controlled at about 50%, suitable initial phosphorus content in the hot metal with higher phosphorus contents is about 0.35% by comprehensively considering various factors, slag systems of higher iron oxide content and higher basicity have higher capacity of dephosphorization.

关键词： hot metal pretreatment dephosphorization kinetic model

Manufacture of the Ultrafine Grain WC/Co Cemented Carbides by Combined Sintering Processing

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International Journal of Minerals,Metallurgy and Materials 1999年第3期13卷 208-213页

作者： Binghai Liu Yue Zhang Shixi Ouyang Qikai Li(Institute of Technical Physics and Chemistry, East China university of science and technology , Shanghai 200237, China)(Material science and Engineering School. university of science and technology Beijing, Beijing 100083, China)(State Key Laboratory for Synthesis and Processing of Advanced Materials. wuhan university of science and technology, wuhan 430070, China,) Institute of Technical Physics and Chemistry East China University of Science and Technology Shanghai 200237 China State Key Laboratory for Synthesis and Processing of Advanced Materials Wuhan University of Science and Technology Wuhan 430070 China Material science and Engineering School University of Science and Technology Beijing Beijing 100083 China

A new kind of sintering process, combined sintering process. i.e. vacuum sintering plus hot isolate pressure sintering (HIP), was introduced for producing ultrafine WC-10% Co (mass fraction. so as the follows) cemented carbides. The effects of some processing parameters on the microstructure and mechanical properties of the obtained cemented carbides were studied. The results show that the rapid shrinkage and the pronounced densification of tile cemented carbides took place during the vacuum sintering stage, which is intinaately correlated with the local liquid sintering occurred during this earl} sintering stage for the high surface activity of ultrafine WC-Co powder. The way of high pressure imposing. isothermal treatment cycle during *** sintering and HIP sintering stage directly influence the densitication of compacts and the mechanical properties of the produced WC-10%Co cemented carbides.

关键词： ultrafine WC-Co cemented carbides vacuum sintering HIP sintering

MODERATE DEVIATIONS AND LARGEDE VIATIONS FOR A TEST OF SYMMETRY BASED ON KERNEL DENSITY ESTIMATOR

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Acta Mathematica Scientia 2008年第3期28卷 665-674页

作者：何晓霞高付清 School of Mathematics and Statistics Wuhan University

Let fn be a non-parametric kernel density estimator based on a kernel function K. and a sequence of independent and identically distributed random variables taking values in R. The goal of this article is to prove mod... 详细信息

关键词： Symmetry test kernel estimator moderate deviations large deviations

On the new results of global attractive set and positive invariant set of the Lorenz chaotic system and the applications to chaos control and synchronization

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science in China(Series F) 2005年第3期48卷 304-321页

作者： LIAO Xiaoxin 1, 2, 3 , FU Yuli 4 & XIE Shengli 4 1. Department of Control science & Control Engineering, Huazhong university of science & technology, wuhan 430074, China 2. School of Automation, wuhan university of science & technology, wuhan 430070, China 3. School of Information, Central South university of Economy, Politics and Law, wuhan 430064, China 4. School of Electronics & Information Engineering, South China university of technology, Guangzhou 510640, China Correspondence should be addressed to Liao Xiaoxin (email: xiaoxin_liao@***) Department of Control science & Control Engineering Huazhong University of Science & Technology Wuhan 430074 China

Constructing a family of generalized Lyapunov functions, a new method is proposed to obtain new global attractive set and positive invariant set of the Lorenz chaotic system. The method we proposed greatly simplifies the complex proofs of the two famous estimations presented by the Russian scholar Leonov. Our uniform formula can derive a series of the new estimations. Employing the idea of intersection in set theory, we extract a new Leonov formula-like estimation from the family of the estimations. With our method and the new estimation, one can confirm that there are no equilibrium, periodic solutions, almost periodic motions, wandering motions or other chaotic attractors outside the global attractive set. The Lorenz butterfly-like singular attractors are located in the global attractive set only. This result is applied to the chaos control and chaos synchronization. Some feedback control laws are obtained to guarantee that all the trajectories of the Lorenz systems track a periodic solution, or globally stabilize an unstable (or locally stable but not globally asymptotically stable) equilibrium. Further, some new global exponential chaos synchronization results are presented. Our new method and the new results are expected to be applied in real secure communication systems.

关键词： Lorenz chaotic system global attractive set positive invariant set globally exponential tracking globally exponential synchronization.

Surface Films Formed on SnO_2 Anode in Lithium Secondary Batteries by FTIR Spectroscopy

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Journal of wuhan university of technology(Materials science) 2008年第5期23卷 662-665页

作者：黄峰 Hubei Refractories and High-temperature Ceramics Key Laboratory Wuhan University of Science and Technology

The chemical composition of the passivating layer formed on nano SnO2 anodes in 1 M LiClO4＋（ethylene carbonate）EC ＋（dimethyl carbonate）DMC at different charge/discharge states in lithium secondary batteries was studied using extra reflectance FTIR spectra. Results show that solvent decomposition reaction that generally occurs on the surface of carbon and alkali metal electrodes also takes place on nano-SnO2 anode, and the major constituent of the passivating layer is Li2CO3 and ROCO2Li. Formation of the passivating layer would certainly lead to the irreversible capacity loss.

关键词： nano-SnO2 anode lithium rechargeable batteries FTIR passivating layer