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Effect of Lead Contents on the Properties of PMSZT Piezoelectric Ceramics

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Journal of Wuhan university of Technology(Materials Science) 2007年第2期22卷 311-314页

作者：陆翠敏 school of Materials Science and engineering Tianjin University of Technology

The effects of Pb content on crystallographic phase, microstructure, electric-properties of PMSZT piezoelectric ceramics were studied. The crystallographic phase and microstructure of the ceramics were examined by using X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The experimental result shows that the samples consist of a mixture of tetragonal and rhombohedral phases in the range of lead contents x=0.95-1.06, grains grow up homogeneously and the minimum value of Curie temperature was obtained with x-=1.02. With Pb content x〈l.02 or x〉1.02, the Curie temperature moves towards a high temperature. A well-situated electric-properties of ET33/E0 （1660）, d33 （344pC/N）, Kp （0.684）, Qm （2350）,tan 3（0.0030） were obtained when lead content x=1.02.

关键词： piezoelectric ceramics crystallographic phase microstructure electric-properties

Method of Distinguishing Hydrologic Drought for Water Supply System

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Transactions of tianjin university 2005年第5期11卷 371-375页

作者：冯平韩松李绍飞 school of civil engineering Tianjin University

It is very common to design water supply system to adjust runoff. Thus it will not meet the practical needs if only the hydrologic drought in natural basin is studied. In practice the natural water balance and water deficits must be researched, i. e. . the adjusting effects of the water supply sys- tem such as a reservoir should be considered, and the drought event be distinguished according to the special system. The problem of drought identification under adjusted runoff was investigated in this study. By considering water transfer during different periods, a method to distinguish hydrologic drought for the water supply system was developed, and a standard drought severity index SWDSI was proposed. The method has been applied in Pan Jiakou water supply system in china. From 1953 to 1997,a total of 14 hydrologic droughts were identified in the water supply system, among which there were 3 severe droughts, 6 moderate droughts and 5 light droughts. The results are in good agreement with the historic drought records.

关键词： drought water supply system - SWDSI drought identification runoff

Recent progresses in application of functionalized graphene sheets

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Science china(Technological Sciences) 2010年第9期53卷 2311-2319页

作者： Lü Peng,FENG YiYu,ZHANG XueQuan,LI Yu & FENG Wei school of Materials Science and engineering,tianjin university,tianjin 300072,china 1. school of Materials Science and engineering Tianjin University Tianjin 300072 China

Graphene,a rapidly rising star on the horizon of material science,has a unique two-dimensional nanostructure as well as exceptional mechanical and electronic *** its short history,graphene has exhibited great potential in various *** order to implement the potential applications,functionalization of graphene is necessary to obtain uniform dispersions for good *** kinds are dominant for functionalization such as covalent and non-covalent *** former is based on the formation of covalent bonds,and the latter the interaction among *** this review,we summarized briefly the recent progress of functionalized graphene sheets (FGs) in different fields,such as optoelectronic materials,sensors,energy storage materials,catalytic,reinforcing components and so on,and also prospected the development trend of FGs in the future.

关键词： functionalized graphene sheets optoelectronic materials sensors energy storage materials catalytic fields

Methods for Progressive Collapse Analysis of Building Structures Under Blast and Impact Loads

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Transactions of tianjin university 2008年第5期14卷 329-339页

作者：李忠献师燕超 school of civil engineering Tianjin University

Progressive collapse of building structures under blast and impact loads has attracted great attention all over the world. Progressive collapse analysis is essential for an economic and safe design of building structures against progressive collapse to blast and impact loads. Because of the catastrophic nature of progressive collapse and the potentially high cost of constructing or retrofitting buildings to resist it, it is imperative that the progressive collapse analysis methods be reliable. For engineers, their methodology to carry out progressive collapse evaluation need not only be accurate and concise, but also be easily used and works fast. Thus, many researchers have been spending lots of effort in developing reliable, efficient and straightforward progressive collapse analysis methods recently. In the present paper, current progressive collapse analysis methods available in the literature are reviewed. Their suitability, applicability and reliability are discussed. Our recent proposed new method for progressive collapse analysis of reinforced concrete frames under blast loads is also introduced.

关键词： progressive collapse analysis building structures blast load impact load

Analysis of Pipeline Damage to Impact Load by Dropped Objects

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Transactions of tianjin university 2006年第B09期12卷 138-141页

作者： YAN Shuwang TIAN Yinghui school of civil engineering Tianjin University Tianjin 300072 China

Marine pipeline damage subjected to dropped objects from platforms or supply vessels is analyzed to introduce an easy and applicable approach to investigating the damage induced by impact load from drop weight. A practical engineering example was presented and analyzed using the commercial program 'ANSYS/LS-DYNA', which is a powerful tool with an explicit dynamic solver. And rational agreement of the results with previous works was obtained. The suggested procedure might be taken as a checking analysis of the protection measures of pipelines in addition to the general risk assessment method.

关键词： pipeline dropped objects damage impact load ANSYS/LS-DYNA

Universal approximation of polygonal fuzzy neural networks in sense of K-integral norms

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Science china(Information Sciences) 2011年第11期54卷 2307-2323页

作者： WANG GuiJun 1 & LI XiaoPing 2 1 school of Mathematics Science,tianjin Normal university,tianjin 300387,china 2 school of Management,tianjin Normal university,tianjin 300387,china 1. school of Mathematics Science Tianjin Normal University Tianjin 300387 China2. School of Management Tianjin Normal University Tianjin 300387 China

In this paper,we introduce polygonal fuzzy numbers to overcome the operational complexity of ordinary fuzzy numbers,and obtain two important inequalities by taking advantage of their fine *** presenting an actual example,we demonstrate that the approximation capability of polygonal fuzzy numbers is ***,the concepts of K-quasi-additive integrals and K-integral norms are *** the polygonal fuzzy numbers space satisfies separability,the density problems for several functions spaces can be studied,by means of fuzzy-valued simple functions and fuzzy-valued Bernstein *** establish that the class of the integrally-bounded fuzzy-valued functions spans a complete and separable metric space in the K-integral ***,in the sense of K-integral norms,the universal approximation of fourlayer regular polygonal fuzzy neural networks for fuzzy-valued simple functions is ***,we show that this type of networks also possesses universal approximation for the class of integrally-bounded fuzzyvalued *** result indicates that the approximation capability which regular polygonal fuzzy neural networks for continuous fuzzy systems can be extended as for general integrable systems.

关键词： polygonal fuzzy numbers K-quasi-additive integrals K-integral norms polygonal fuzzy neural networks universal approximations

Stochastic DEA model with undesirable outputs: An application to the prediction of anti-HIV therapy efficiency

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Progress in Natural Science:Materials International 2006年第7期16卷 753-759页

作者： BIAN Fuping and TANG Xiaoqin ( Department of Mathematics, school of Science, tianjin university, tianjin 300072, china Liuhui Institute of Applied Mathematics, Nankai university and tianjin university, tianjin 300072, china) [a]Department of Mathematics School of Science Tianjin University Tianjin China [b]Liuhui Institute of Applied Mathematics Nankai University and Tianjin University Tianjin China

This paper proposes a stochastic prediction DEA model with undesirable outputs and simplifies the process using chance-constrained techniques in order to obtain an equivalent linear programming formulation. The existence and stability of the optimal solutions have been proved. And the model is used to describe and predict the efficiency of anti-HIV therapy in AIDS patients.

关键词： data envelopment analysis (DEA) decision making units (DMU) undesirable outputs stochastic DEA model anti-HIV therapy.

K-quasi-additive fuzzy integrals of set-valued mappings

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Progress in Natural Science:Materials International 2006年第2期16卷 125-132页

作者： WANG Guijun and LI Xiaoping ( school of Mathematics Science, tianjin Normal university, tianjin 300074, china school of Management, tianjin Normal university, tianjin 300074, china) [a]school of Mathematics Science Tianjin Normal University Tianjin China [b]school of Management Tianjin Normal Universit Tianjin China

We first define the quasi-addition and quasi-multiplication operations by introducing the inductive operator, and then, in the K-quasi-additive fuzzy measure space, we establish the K-quasi-additive fuzzy integral of a generally measurable set-valued mapping. Applying the integral transformation theorem, some basic properties of the K-quasi-additive fuzzy integrals with respect to this kind of set-valued mapping are studied. Finally, the generalized monotone convergence theorems of this kind of fuzzy integrals are obtained.

关键词： set-valued mapping inductive operator integrable selections K-quasi-additive fuzzy integrals.

Alkylation mechanism of benzene with 1-dodecene catalyzed by Et_3NHCl-AlCl_3

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Science china Chemistry 2010年第5期53卷 1101-1106页

作者： QI GuoPeng 1,JIANG Feng 1,SUN XueWen 2 & ZHAO SuoQi 2 1school of Chemical engineering,tianjin university,tianjin 300072,china 2State key Laboratory of Heavy Oil Processing,Petroleum university of china,Beijing 102249,china 1. school of Chemical engineering Tianjin University Tianjin 300072 China2. State key Laboratory of Heavy Oil Processing Petroleum University of China Beijing 102249 China

The isotope exchange method was employed to investigate the catalytic mechanism of ionic liquid in alkylation of benzenes with *** is proposed that alkylation was induced by the Lewis acid AlCl3 which attracted π electrons of 1-dodecene to shift toward 1-carbon,thus forming a carbonium *** carbonium ion further reacted with benzenes to form a *** to unstabilit of the complex,a deuterated ring proton was transferred into an electronegative 1-carbon of the side chain to substitute for the AlCl3,accordingly 2-phenyldodecane was generated.

关键词： ionic liquid alkylation mechanism deuteriobenzene isotope exchange method