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Proton Conducting Composite Membranes from Sulfonated Polyether Ether Ketone and SiO_2

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Journal of Wuhan university of technology(Materials Science) 2009年第1期24卷 95-99页

作者：张高文 college of Chemistry and Environment Hubei University of Technology

Proton conducting composite membranes from sulfonated polyether ether ketone and SiO2 for direct methanol fuel cell （DMFC） application were prepared with sulfonated polyether ether ketone（SPEEK） and tetracethoxy silane（TEOS） by sol-gel method. The covalent crosslinking structure was formed between —SO3H of SPEEK via SiO2. The SEM images show that the interfacial compatibility of SPEEK and SiO2 is improved obviously and SiO2 disperses uniformly in the polymer matrix and the particle diameter of SiO2 does not exceed 40 nm. The proton conductivity of composite membranes decreases slightly compared with the SPEEK membrane while the methanol permeability and swelling of composite membrane are improved remarkablely owing to covalent cross-linking between —SO3H and SiO2 .

关键词： direct methanol fuel cell sulfonated polyether ether ketone sol-gel method proton conductivity methanol permeability

Three-dimensional elasticity solution of simple-supported rectangular plate on point supports, line supports and elastic foundation

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Science china(Technological Sciences) 2009年第3期52卷 584-589页

作者： XU YePeng1 & ZHOU Ding2 1 School of Science, Nanjing university of Science and technology, Nanjing 210094, china 2.college of Civil engineering, Nanjing university of technology, Nanjing 210009, china 1. School of Science Nanjing University of Science and Technology Nanjing 210094 China 2. college of Civil engineering Nanjing University of Technology Nanjing 210009 China

This paper studies the bending of simple-supported rectangular plate on point supports, line supports and elastic foundation. On the basis of three-dimensional elasticity theory, the exact expressions of the displacement functions, which satisfy the governing differential equations and the simply supported boundary conditions at four edges of the plate, are analytically derived. The reaction forces of the in- termediate supports are regarded as the unknown external forces acting on the lower surface of the plate. The unknown coefficients are then determined by the boundary conditions on the upper and lower surfaces of the plate. Comparing the numerical results obtained from the proposed method to those obtained from Kirchhoff plate theory, Mindlin plate theory and those obtained from the commer- cial finite element software ANSYS, the high accuracy of the present method has been demonstrated.

关键词： rectangular plate point support line support elastic foundation displacement stress three-dimensional elasticity solution

A new method to improve surface morphology of Ni-Fe-Mo-Co alloy electrode and its catalytic activity for HER

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Rare Metals 2007年第3期26卷 205-212页

作者： LUO Beiping REN Buye XU You ZHENG Yajie Department of Chemistry and Chemical engineering Hunan Institute of Science and Technology Yueyang 414000 China college of Metallurgical Science and engineering Central South University Changsha 410083 China Research Institute of Materials Science South China University of Technology Guangzhou 510640 China

A new pretreatment method has been developed to improve the catalytic activity of the Ni-Fe-Mo-Co alloy electrode for hydrogen evolution reaction （HER）. The procedure involves pre-electrolyzing the Ni-Fe-Mo-Co alloy electrode in 30% KOH solution containing 10% potassium sodium tartrate at 70℃ for 2 h, until some of the Mo and Fe elements are leached out. The surface morphology of the Ni-Fe-Mo-Co alloy demonstrates a unique hive-like structure after the pre- treatment, which has the pore size in a nanometer range （about 50 nm）, a very large real surface area, and good stability. The results of the electrochemical studies show that compared to other similar electrode materials and the treated Ni-Fe-Mo-Co electrode by leaching method, the pre-treated Ni-Fe-Mo-Co electrode has a much lower overpotential and much higher exchange current density for HER. In addition, a long-term continuous electrolysis test with a current interruption shows that the Ni-Fe-Mo-Co alloy has excellent catalytic stability.

关键词： catalytic activity surface treatment Ni-Fe-Mo-Co alloy hydrogen evolution electrodeposition

Investigation of 'chazi'(damaged-enamels)on Chenghua doucai Porcelains

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Science china(Technological Sciences) 2009年第6期52卷 1722-1729页

作者： DU Feng1 & SU BaoRu2 1 Institute of Chemistry & Molecular engineering,Qingdao university of Science & technology,Qingdao,china 2.college of Information Science & technology,Qingdao university of Science & technology,Qingdao,china Institute of Chemistry & Molecular engineering Qingdao University of Science & Technology Qingdao China college of Information Science & technology Qingdao University of Science & Technology Qingdao China

At the end of the 1950s,Sun Yingzhou considered that the 'chazi'(damaged colour)on Chenghua doucai imperial porcelain as a defect was originally produced in firing process during Chenghua period(1465―1487).Researchers in china have accepted his *** any fragment with the 'chazi' has never been found in several tons of Chenghua imperial sherds excavated from Ming imperial kiln site in *** china,few scholars have questioned the formation of 'chazi',and further investigated *** researchers at the Research Laboratory in the British Museum,employing unde-structive EDXRF,have analyzed the chemical composition of the 'chazi'(damaged colour)on a Chen-ghua doucai stem cup in the museum,and they have confirmed that the 'chazi'(damaged colour)was caused by the fire of the Jianfu palace in the Forbidden City in *** on their research,the authors studied the colour chemical principle of the 'chazi's' formation *** to the ceramic technology principle,scientific reasoning for the 'chazi' was carried *** the help of the history of Qing court,the brainteaser of the 'chazi' was totally uncovered,the misunderstanding for the 'chazi' has also been *** research also suggests that employing modern science and technology is a direction to study Chinese ancient ceramic further.

关键词： Chenghua doucai porcelains court eunuchs the set on fire at the Jianfu palace ’chazi’(damaged-enamels) the British Museum colour chemical principle archaeology using science and technology

A New Genetic Algorithm Based on Niche Technique and Local Search Method

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Journal of university of Science and technology Beijing 2001年第1期8卷 63-68页

作者： Jinwu Xu, Jiwen Liu mechanical engineering School, university of Science and technology Beijing, Beijing 100083, china Univ Sci & Technol Beijing Sch Mech Engn Beijing 100083 Peoples R China

The genetic algorithm has been widely used in many fields as an easy robust global search and optimization method. In this paper, a new generic algorithm based on niche technique and local search method is presented under the consideration of inadequacies of the simple genetic algorithm. In order to prove the adaptability and validity of the improved genetic algorithm, optimization problems of multimodal functions with equal peaks, unequal peaks and complicated peak distribution are discussed. The simulation results show that compared to other niching methods, this improved genetic algorithm has obvious potential on many respects, such as convergence speed, solution accuracy, ability of global optimization, etc.

关键词： genetic algorithm (GA) niche technique local search method

Survival probability and ruin probability of a risk model

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Applied Mathematics(A Journal of Chinese Universities) 2008年第3期23卷 256-264页

作者： LUO Jian-hua college of Science,Central south university of Forestry and technology,Changsha 410004,china Institute of Statistics,Central south university of Forestry and technology,Changsha 410004,china. college of Science Central South University of Forestry and Technology Changsha 410004 China Institute of Statistics Central South University of Forestry and Technology Changsha 410004 China

In this paper, a new risk model is studied in which the rate of premium income is regarded as a random variable, the arrival of insurance policies is a Poisson process and the process of claim occurring is p-thinning process. The integral representations of the survival probability are gotten. The explicit formula of the survival probability on the infinite interval is obtained in the special casc cxponential *** Lundberg inequality and the common formula of the ruin probability are gotten in terms of some techniques from martingale theory.

关键词： risk model thinning process survival probability martingale ruin probability integral representation

PROPERTY AND METALLOGENIC CHARACTERISTICS OF ALKALI-RICH PORPHYRY IN WESTERN MARGIN OF YANGTZE PLATFORM

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Journal of Central south university 1998年第2期10卷 57-60页

作者： Hu Xiangzhao (college of Resources, Environment and Civil engineering,Central south university of technology, Changsha 410083, china) college of Resources Environment and Civil Engineering Central South University of Technology Changsha 410083 China

The age of alkali rich porphyries in the western margin of Yangtze Platform is 30—50 Ma; the minerals mainly are orthoclase, quartz, plagioclase; the chemical composition is alkali rich [(K 2O+Na 2O)>8%],high potash[(K 2O+Na 2O)=5.09%-8.30%]; the content of  REE  is relatively low, LREE is concentrated, without anomaly of europium; the average initial ratio of 87 Sr/ 86 Sr is 0.7073; the value of δ 34 S similar to that of the meteoritic sulfur; the ratio of Pb isotope corresponds to that of upper mantle; metallogenic types belong to Cu, Mo, Au, Ag, Pb, Zn polymetal mineralization and rare, rare earth metal mineralization.

关键词： petrology geochemistry alkali rich porphyry metallogenic characteristics

New concept and new theory of mobility calculation for multi-loop mechanisms

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Science china(Technological Sciences) 2010年第6期53卷 1598-1604页

作者： ZHANG YiTong & MU DeJun mechanical engineering college of Yanshan university,Qinhuangdao 066004,china 1. mechanical engineering college of Yanshan university Qinhuangdao 066004 China

In 2005,Gogu,a Frenchman,analyzed 35 different existing formulas for mobility calculation and pointed that the formulas for quick mobility calculation had some limitations and were not ***,looking for a general and simple mobility formula is still a hot topic in *** the meantime,it is also an important topic to complete the mechanism *** proposed a new method that can avoid determining virtual constraints in 2008,but the method is still not *** solve the problem,this paper defines the new concepts of link-group rank,general-kinematic-pair rank,virtual pair,virtual loop,and virtual-loop rank,and gives a new simple and general *** method converts multi-loop mechanisms into some independent virtual loops,simplifies the problem,avoids calculating virtual constraints,and reduces the calculation *** is proved that the new formula is simple,general and effective through the mobility analysis of several different kinds of *** application of this formula will provide great convenience for general engineers in mobility calculation.

关键词： multi-loop mechanism mobility general kinematic pair virtual loop

Effect of Preparation Methods on mechanical Properties of PVA/HA Composite Hydrogel

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Journal of Bionic engineering 2010年第3期7卷 235-243页

作者： Dekun Zhang~1, Junjie Duan~1, Dagang Wang~2, Shirong Ge~2 1. School of Materials Science and engineering, china university of Mining and technology Xuzhou 221116, P. R. china 2. School of mechanical and Electrical engineering, china university of Mining and technology, Xuzhou 221116, P. R. china [a] School of Materials Science engineering China University of Mining technology Xuzhou 221116 P. R. China [b] School of Mechanical Electrical engineering China University of Mining technology Xuzhou 221116 P. R. China

Poly(vinyl alcohol) (PVA)/hydroxyapatite (HA) composite hydrogel specimens were prepared with 15% PVA and 1%,2%, 3%, 4% and 5% HA by repeated freezing-thawing. The tests of static and dynamic mechanical properties were carried out todiscuss the influence of different contents of HA and freezing-thawing cycles on the mechanical properties of PVA/HA compositehydrogel. The results of static mechanical tests showed that the PVA/HA composite hydrogel with 3% HA and ninefreezing-thawing cycles had excellent stress relaxation properties, higher relaxation ratio, lower stress equilibrium value andpresented better properties of creep and recovery. The results of dynamic mechanical test showed that the PVA/HA compositehydrogel with nine freezing-thawing cycles had higher storage modulus and loss modulus, so was the PVA/HA compositehydrogel with 3% HA.

关键词： composite hydrogel HA contents freezing-thawing cycles static properties dynamic properties