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Microscopic Analysis of Inelastic Proton Scattering off ^(28)Si

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Chinese journal of nuclear physics 1995年第2期17卷 124-128页

作者： An Zhu(institute of Nuclear science and Technology,sichuan university,chengdu 610064) sichuan Univ Chengdu China

The elastic and inelastic scattering data of 22 MeV protons from 28Si havebeen *** measured differential cross sections were compared with microscop-ic DWBA calculations in which nuclear transition densities extracted from （e,e’） exper-iments were used directly.A density-dependent nucleon-nucleon effective interaction inthe low-energy region,Complex Effective Interaction with Gaussian form factor（CEG）,was applied in our *** problems associated were discussed.

关键词： Proton inelastic scattering Local momentum approximation Nucleonnucleon effective interaction

Effect of rare earths on phase transformation in as-cast ZA27 alloy dur-ing compressive creep

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Rare Metals 2003年第4期22卷 259-264页

作者： WEIXiaowei SHENBaoluo DepamnentofAppliedPhysics UniversityofElectronicScienceandTechnologyofChinaChengdu610045China DeparlanentofMetalscience SichuanUniversityChengdu610065China

The effect of the mixed rare earths of Ce on the phase transformation in ascast ZA 27 alloy during compressive was investigated under 37 MPa and at 160 deg C by X-raydiffraction technique and SEM. The results showed that the as cast microstructure of ZA 27-RE alloyconsisted of a dendritic al-rich alpha' surrounded by Zn-rich beta' phase, interdendritic epsilonphase and Zn-rich eta phase together with a complex Z phase which was a complex constitute compound,(RE,Cu)al_5Zn_(16), dispersed in crystal interfaces or branch crystal interfaces and stable duringcompressive creep test at 160 deg C. The phase transformations of ZA 27-RE alloy, decomposition ofbeta' phase arid four transformation, were delayed by the addition of rare earths, also the lamellarstructure and the spheroidized structure in ZA 27-RE alloy were finer than in ZA 27 alloy duringcompressive creep test at 160 deg C at the same creep time, and the compressive creep resistance ofZA 27-RE alloy was higher than that of ZA 27 alloy.

关键词： microstructure change compressive creep rare earths ZA 27 alloy

Characterization of ZnO Based Varistor Derived from Nano ZnO Powders and Ultrafine Dopants

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Journal of Materials science & Technology 2005年第2期21卷 183-186页

作者： Weizhong YANG, Dali ZHOU, Guangfu YIN, Runsheng WANG and Yun ZHANG College of Material science and engineering, sichuan university, chengdu 610064, china Coll. of Mat. Sci. and Eng. Sichuan Univ. Chengdu 610064 China

Nanosized ZnO powders were prepared with a two-step precipitation method. The average size of ZnO particles was about 80 nm and their size distribution was narrow. Combining with ultrafine additive powders, ZnO base varistor was produced via an oxide mixing route. ZnO varistor derived from normal reagent grade starting materials was investigated for comparison purpose. Outstanding microstructure of the ZnO varistor derived from nanosize ZnO powders and ultrafine dopants was obtained: uniform distribution of fine ZnO grains (less than 3 microns), grain boundary and the dopant position. Higher varistor voltage (U=492 V/mm) and nonlinear coefficient (α=56.2) as well as lower leakage current (TL=1.5 μuA) were achieved. The better electrical properties were attributed to the uniform microstructure, which in turn led to stable and uniform potential barriers. also this improved technique is more feasible for producing ZnO nanopowders and resulting varistor in large scales.

关键词： Zinc oxide (ZnO) Varistor Nanopowders Ultrafine dopants Two-step precipitation

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CONTINUOUS L-DOMAINS

Chinese Annals of Mathematics,Series B 1996年第3期17卷 263-270页

作者： LIANG JIHUA LIU YINGMING(institute of Mathematics, sichuan university, chengdu 610064, china.)(Project supported by the National Natural science Foundation of china.) sichuan UNIV INST MATHCHENGDU 610064PEOPLES R CHINA

Two characterization theorems of continuous L-domain are given. Then a problem raisedby J. D. Lawson and M. Mislove is solved.

关键词： L-domain Continuous DCPO Domain theory

EFFECT OF PAN-MILLING ON RHEOLOGICal PROPERTIES OF HIGH DENSITY POLYETHYLENE

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Chinese Journal of Polymer science 2000年第5期18卷 397-403页

作者： Hua Huang Polymer Research institute, sichuan university, chengdu 610065, china sichuan Univ Polymer Res Inst Chengdu 610065 Peoples R China Shanghai Jiao Tong Univ Sch Chem & Chem Technol Shanghai 200240 Peoples R China

The effect of pan-milling on the rheological properties of high density polyethylene (HDPE) was studied. An innovative milling apparatus, viz. an inlaid pan-mill, was used. Melt indexer, capillary rheometer, Haake Rheocord 90 single-screw extruder and Brabender rheometer were used to evaluate the rheological properties of HDPE. HDPE with higher initial molecular weight and larger particle size was easier to degrade under pan-milling stress, as indicated by the melt index. Pressure oscillation in capillary flow occurred at significantly higher shear stress and shear rate for milled HDPE than for unmilled HDPE. The apparent shear viscosity of HDPE decreased with increasing times of milling. After milling, the flow activation energy decreased and thus the sensitivity of viscosity to temperature was reduced. Die pressure and torque during single screw extrusion were reduced significantly after milling. Plasticizing time as measured in a Brabander mixer decreased markedly with increasing milling times.

关键词： high density polyethylene rheological properties pan-milling

Minority population and sustainable development in mountain regions a case study of the Tibetan inhabited region in sichuan, china

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Journal of Geographical sciences 1998年第4期8卷 12-20页

作者： CHEN Yong HE Ginxi institute of Population Research, sichuan university, chengdu 610064, china AI Nanshan institute of Environmental science & engineering, sichuan university, chengdu 610064, china

china boasts 56 nationalities who are mostly inhabited in the sparsely populated mountain regions in West china. Like many other places in the Han nationality distributed regions, minority nationality inhabited regions are also facing the challenge of sustainable development in terms of both natural and human factors. Taking the Tibetan inhabited regions (TIR) in sichuan Province as a case, this paper points out some major problems in the process of economic development in perspective of sustainability and leaves some hints for development strategies. While natural conditions such as geological instability are playing a major role to the environmental degradation, human activities and improper use of resources might constitute an important agent in the environmental deterioration. In order to promote local economic development and improve people’s living standard, sustainable planning is expected to be made and people’s awareness of sustainability should be strengthened.

关键词： Tibetan inhabited region (TIR) minority population sustainable development development strategy.

Land Use of the Three Gorges Reservoir Area and the Effect on Its Landscape Pattern in the Recent 50 Years

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Wuhan university Journal of Natural sciences 2006年第4期11卷 910-914页

作者： HUANG Zhiqin 1,2,3 , ZHOU Wancun 1 ,ZHOU Jieming 4 , ZHU Mingcang 3,5 1. institute of Mountain Hazards and Environment, Chinese Academy of sciences , chengdu 610041, sichuan, china 2. Graduate university of Chinese Academy of sciences, Beijing 100049, china 3. sichuan institute of Land Resource Management, chengdu 610041, sichuan , china 4. Department of Resources and Environment science, sichuan Normal university , chengdu 610061, sichuan, china 5. College of Information engineering, chengdu university of Technology, chengdu 610059, sichuan, china institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu Sichuan China Graduate university of Chinese Academy of sciences Beijing China sichuan institute of Land Resource Management Chengdu Sichuan China Department of Resources and Environment science Sichuan Normal University Chengdu Sichuan China College of Information engineering Chengdu University of Technology Chengdu Sichuan China

The paper makes detailed analysis on the changing processes of the main types of land use in Three Gorges Reservoir Area through the techniques of RS （Remote Sense） and GIS （Geography Information System）. Based on the theory of landscape ecology, many types of landscape pattern indexes are calculated and made correlation analysis. The results indicate that： in 1995 the ecological environment of Three Gorges Reservoir Area was the most vulnerable in the recent 50 years, but resumed in 2002; the landscape pattern diversity index, fractal dimension index and fragmentation index has close correlation with the area of land use/cover change （LUCC）. The research also releases that the increase of the cultivated land, grassland and construction land deteriorates the landscape ecological pattern, while the increase of forest land area will help restore the landscape ecological pattern to its original state. The rapid change of grassland is an important index of the change of landscape pattern, because it has the most effect on change of landscape pattern index.

关键词： the Three Gorges Reservoir Area land use/cover change landscape pattern.

Effect of barium on the refinement of primary aluminum and eutectics in a hypoeutectic al-Si alloy

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Rare Metals 2003年第3期22卷 192-196页

作者： LI Wei, FAN Hongyuan, ZHANG Xianju, and SHEN BaoluoSchool of Manufacturing science and engineering, sichuan university, chengdu 610065, china School of Manufacturing science and engineering Sichuan University Chengdu 610065

The effect of barium on the refinement of primary aluminum and on themodification of eutectics in a hypoeutectic aluminum-silicon alloy was investigated. The resultsindicate that barium not only modifies the eutectic silicon but also refines the primary aluminumand there is a relationship between the retained barium and the second spacing of primary *** of barium-treated commercial al-Si hypoeutectic alloy show that barium is a bettermodifier than sodium when there is a longer holding time.

关键词： non-ferrous metal barium modification primary aluminum eutectic al-Sialloy

Theoretical analysis and experiment of micromechanics and mechanics-optics coupling of distributed optic-fiber crack sensing

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中国科学：技术科学英文版 2011年第S1期54卷 185-191页

作者： LIU HaoWu 1,2,CHEN Jiang 2,SUN Man 3 & DING Rui 2 1 State Key Laboratory of Hydraulics and Mountain River engineering,sichuan university,chengdu 610065,china 2 School of Water Resource Hydropower,sichuan university,chengdu 610065,china 3 School Electrical engineering and Information,sichuan university,chengdu 610065,china sichuan Univ State Key Lab Hydraul & Mt River Engn Chengdu 610065 Peoples R China sichuan Univ Sch Water Resource Hydropower Chengdu 610065 Peoples R China sichuan Univ Sch Elect Engn & Informat Chengdu 610065 Peoples R China

The micromechanical behaviors and mechanics-optics coupling effects of optic-fiber-concrete complex in the distributed optic-fiber sensing concrete-crack technology,which was used in health monitoring of Wu Gorge Bridge on Yangtze River and a large dam successfully,have been investigated.A micromechanical theoretical analysis method and micromechanical frictional contact bi-interface model,as well as a modified optical theoretical analysis method of the mechanics-optics coupling effects are presented.A series of verification experiments,including mechanical experiments and mechanics-optics coupling experiments,have been *** results of micromechanical theoretical analysis and the analysis of the modified theory of mechanics-optics coupling along with mechanical and optical experimental data are shown to be in close *** the micromechanical theory and the modified theory of mechanics-optics coupling with their analysis methods can not only enhance credibility of this novel distributed sensing technology but also provide a way to understand its sensing mechanism and optimize its technical details and system.

关键词： optic-fiber sensing mechanics-optics coupling micromechanics health monitoring concrete structure crack detection