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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 四川大学四川成都

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

The Wenchuan earthquake creation of a rich database of building performance

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Science china(Technological Sciences) 2010年第10期53卷 2668-2680页

作者： SUN BaiTao & ZHANG GuiXin institute of Engineering Mechanics, china Earthquake Administration, Harbin 150080, china institute of Engineering Mechanics China Earthquake Administration Harbin China

After the Wenchuan earthquake,The institute of Engineering Mechanics (IEM) performed an extensive and comprehensive damage survey of the large area affected by the earthquake. Seismic codes in china were revised and updated after the catastrophic 1976 Tangshan earthquake. However,until the Wenchuan earthquake the seismic code provisions were not tested by a large earthquake. Some 5000 buildings,exposed to intensities VI to XI,were investigated in great detail immediately after the earthquake. The investigation and the surveys covered both seismically designed (fortified) buildings and non-code compliant buildings. In the process a comprehensive and documented database of building performance was compiled,which would be very valuable for further research,improvement of the seismic code,improvement of the construction practices,and disaster mitigation planning and management. The database dominantly contains the most prevalent structural types in the region: 1) reinforced and un-reinforced masonry structures; 2) masonry buildings with reinforced frame in the lower stories,and 3) reinforced concrete frame structures. Observed damage characteristics of various structural types were studied and documented,damage patterns analyzed,and corresponding damage probability matrices derived from the data collected during this survey. It is our hope that this investigation and the published material will be utilized for the revision of the seismic codes,leading to a higher level of life safety and damage reduction in future earthquakes.

关键词： Wenchuan earthquake building damage vulnerability damage probability matrices

Building damage in Dujiangyan during Wenchuan Earthquake

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Earthquake Engineering and Engineering Vibration 2008年第3期7卷 263-269页

作者： Zhang Minzheng and Jin Yingjie institute of Engineering Mechanics, china Earthquake Administration, Harbin 150080, china Professor Graduate Student institute of Engineering Mechanics China Earthquake Administration Harbin China

A field damage survey of 1,005 buildings damaged by the Wenchuan Earthquake in Dujiangyan City was carried out and the resulting data was analyzed using the statistical method. It is shown that buildings that were seismically designed achieved the desired seismic fortification target; they sustained less damage than the non-seismically designed buildings. Among the seismically designed buildings investigated, RC frame buildings performed the best in terms of seismic resistance. Masonry buildings with a ground story of RC frame structure were the second best, and masonry buildings performed the worst. Considering building height, multistory buildings sustained more severe damage than high-rise buildings and 2- and 3-story buildings. Compared to residential buildings, public buildings, such as schools and hospitals, suffered more severe damage.

关键词： Wenchuan Earthquake Dujiangyan building damage seismic intensity field survey

Two types of changes in apparent resistivity in earthquake prediction

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Science china Earth Sciences 2011年第1期54卷 145-156页

作者： DU XueBin1,2 1Lanzhou institute of Seismology, china Earthquake Administration, Lanzhou 730000, china 2Lanzhou Base of Earthquake Science institute, china Earthquake Administration, Lanzhou 730000, china Lanzhou institute of Seismology China Earthquake Administration Lanzhou China Lanzhou Base of Earthquake Science institute China Earthquake Administration Lanzhou China

Two types of changes in apparent resistivity (AR) have been linked to earthquake occurrences. This paper studies the changes and their causes, in detail with the ultimate purpose of developing and assessing a method of earthquake (EQ) prediction. The AR changes of the first type (CFT) are considered to be precursors related to earthquakes (EQs); these appear mostly in the medium-term period before EQs and in the short-term period preceding EQs. The changes of the second type (CST) are characterized by a turning anomaly of a long-trend AR variation or the drastically descending/ascending anomaly superimposed on such a variation; these appear synchronously in large areas, such as the Chinese mainland, and northern and northwestern china, ect. Their spatio-temporal clusters correspond well to high seismicities in the areas and distant great EQs around the Chinese mainland. Based on the behaviors of the two types of changes, the AR changes observed prior to the Ms8.0 Wenchuan EQ of 2008 are studied. The results show that in the medium-term period before the EQ, noticeable anomalies appeared synchronously at four stations around the Songpan-Ganzi active block, but only weak upward changes were observed in the short-term period preceding the EQ, which caused the prediction of the imminent EQ to fail.

关键词： strong earthquake apparent resistivity two types of changes spatio-temporal cluster Wenchuan earthquake

Control of the Rendition Wavelength Shifts of Color Lippmann Holograms Recordedin Single-layer panchromatic Silver-halide Emulsion

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Chinese Journal of Lasers 2000年第2期9卷 155-160页

作者： ZHU Jianhua, GUO Lurong, LI Zuoyou, LIU Zhenqing (Information Optics institute, Sichuan University, Chengdu 610064, china institute of Southwest Find Physics, Chengdu 610003, china ) 四川大学四川成都中国工程物理研究院西南流体物理所四川成都

Russian PFG-03C panchromatic ultra-high resolution silver-halide emulsion is regarded as the most successful material for the fabrication of color reflection holograms. But the lack of established and reliable processing sequences prevents its practical applications in business and everyday life. Though much attention is drawn upon the processing of PFC-03C color reflection holograms, the color desaturation is still a problem. The article describes the new processing of color holograms recorded in PFC- 03C plates which is demonstrated experimentally to have the capacity of controlling the rendition wavelength shifts and improving the color desaturation effectively. The rendition spectra of Red-Green-Blue (R. G. B. ) single-line reflection holographic gratify, and the color reflection hologram as well, are given in this paper.

关键词： color holography reflection holograms rendition wavelength color desaturation

Phase Development and Crystallization Kinetics of NiTi Prepared by Mechanical Alloying

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Journal of Materials Science & Technology 2003年第6期19卷 560-562页

作者： Xunyong JIANG, Xueping GAO and Deying SONGinstitute of new Energy Material Chemistry, Nankai University, Tianjin 300071, chinaDepartment of Materials Science and Engineering, Tianjin institute of Technology, Tianjin 300191, china Inst. of new Energy Mat. Chem. Nankai Univ. Tianjin 300071 China Dept. of Mat. Sci. and Eng. Tianjin Inst. of Technol. Tianjin 300191 China

NiTi alloy is produced by mechanical alloying(MA). It becomes amorphous after milling for enough time, such as 100 h in this paper. DSC measurement shows that the crystallization temperature is 676 K for the amorphous powder. Activation energy of crystallization is 199.98 kJ/mol for MA powder, which is lower than that of amorphous prepared by magnetron sputtering. Avrami parameter of crystallization is 1.07.

关键词： NiTi Mechanical alloying Amorphous Crystallization

Randomization of Q_(p) spaces on the unit ball of C^(n)

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Science china Mathematics 2005年第Z1期48卷 306-317页

作者： LI Bo & OUYANG Caiheng Department of Mathematics, State University of new York at Buffalo, Buffalo, NY 14260, USA Wuhan institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, china Department of Mathematics State University of New York at Buffalo Buffalo USA Wuhan institute of Physics and Mathematics Chinese Academy of Sciences Wuhan China

In this paper, we study the random power series of several complex variables,and give some sufficient conditions for random power series to belong to Qp and Qp,0spaces by means of their characterizations of Carleson m... 详细信息

关键词： random power series, function spaces, the unit ball.

FROM UNWEIGHTED TO WEIGHTED GENERALIZED FAREY ORGANIZED TREE AND THE PYRAMID NETWORKS

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Journal of Systems Science & Complexity 2010年第4期23卷 681-700页

作者： Yong LI·Jinqing FANG·Qiang LIU china institute of Atomic Energy,Beijing 102413,china. china institute of Atomic Energy Beijing China

Generalized Farey tree network （GFTN） and generalized Farey organized pyramid network （CFOPN） model are proposed, and their topological characteristics are studied by both theoretical analysis and numerical simulations, which are in good accordance with each other. Then weighted GFTN is studied using cumulative distributions of its Farey number value, edge weight, and node strength. These results maybe helpful for future theoretical development of hybrid models.

关键词： Generalized Farey organized pyramid network topological properties weighted generalized Farey tree network.

Preliminary analysis of the hanging wall effect and velocity pulse of the 5.12 Wenchuan earthquake

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Earthquake Engineering and Engineering Vibration 2009年第2期8卷 165-177页

作者： Liu Qifang and Li Xiaojun institute of Engineering Mechanics, china Earthquake Administration, Harbin 150080, china Associate Professor Professor institute of Engineering Mechanics China Earthquake Administration Harbin China

A preliminary study of the PGA attenuation, hanging wall effect and velocity pulse characteristics from the 2008 Wenchuan earthquake ofMS -8.0 is described in this paper. The study was carried out through analyses in the time and frequency domains of main earthquake records. In the PGA attenuation study, records from 316 stations less than 1000 km from the surface rupture of the fault were used as a database and attenuation relationships were developed and compared with some existing relationships that are widely used in china's Mainland, Chinese Taiwan and the US. At the same time, records from 28 stations less than 100 km from the fault were used to study the hanging wall effect and velocity pulse characteristics of this earthquake based on the distribution of PGA, PGV, spectral acceleration, and the velocity pulse peak, and the results are compared with the 1999 Chi-Chi earthquake. In addition, the large PGAs of the UD components observed in this event are also discussed in this paper. From the results of the preliminary study, some conclusions are developed and suggestions for further research are proposed.

关键词： Wenchuan earthquake hanging wall effect velocity pulse attenuation