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Structures and physical properties of rigid polyurethane foams with water as the sole blowing agent

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Science China Chemistry 2006年第4期49卷 363-370页

作者： LI Xiaobin1,2. CAO Hongbin1 & ZHANG Yi1 1. Institute of Process Engineering, chinese academy of sciences, beijing 100080, China 2. {2. School of the chinese academy of sciences, beijing 10003., China 1. Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China 2. graduate School of the chinese academy of sciences Beijing 100039 China

Rigid polyurethane foams blown by varying water level were prepared in this study. The structures and physical properties of rigid polyurethane foams blown by water were measured with FT-IR, universal testing machine (Instron3.65), scanning electron microscope (SEM) and differential scanning calorimeter (DSC). The results show that polyurea and polybiuret were the typical charac- teristics, and the cream time and gel time were shorter for the fully water blown rigid foams than that for the fully cyclopentane blown foams. The density of foam samples decreased from 45.0 kg/m3.to 2..4 kg/m3.with the increase of water level from 3.pph to 7 pph. Compressive strength exhibited the similar behavior with density. The average cell size of foam samples ranged from 2.1 μm to 3.6 μm with the increase of water level from 3.pph to 7 pph, respectively. At the same time, poorer dimen- sional stability was encountered with the increase of average cell size due to fast diffusion rate of CO2.out of the foam. The results of thermal analysis show that the glass transition temperature (Tg) shifted to a higher temperature with the increase of isocyanate level when more water was used as chemical blowing agent.

关键词： polyether polyol, polyurethane rigid foam, compressive strength, dimensional stability, cell size, glass transition temperature.

Geographical Agglomeration of chinese Manufacturing Industries

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中国人口·资源与环境：英文版 2007年第2期5卷 3-11页

作者： Zhang Hua 1, 2. Zheng Wei3.1. Institute of Geographical sciences and Natural Resources Research, chinese academy of sciences, {2. 100101, China 2. {3. School of the chinese academy of sciences, beijing 10003., China 3. School of Geography, {2. Normal University, {2. 100875, China Institute of Geographical sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China graduate School of the chinese academy of sciences Beijing 100039 China School of Geography Beijing Normal University Beijing 100875 China

Based on the plant level data from the First National Census of Basic Units, the Second National Census of Basic Units, and the First National Economic Census of China, this paper ex- amines the geographical agglomeration of chinese manufacturing industries at a more disaggregated level both by industrial classi-fication and spatial unit analysis. Applying the agglomeration index proposed by Maurel and Sedillot, studies show that the most agglomerated industries are resource-intensive, and capital and technology intensive while industries demanding localized inputs or serving localized markets or favored by local governments are fairly dispersed. The more disaggregated industries are more spa- tially agglomerated. At the finer spatial scale, industries are more dispersed. Results indicate that within-county spillovers are stronger than nearby-county spillovers, and within-prefecture spillovers are stronger than nearby prefecture spillovers. Local- ized spillovers are still quite substantial at a range beyond that of counties. Comparing the agglomeration index of chinese manu- facturing industries in 1996, 2.01 and 2.04, agglomeration seems to be a general tendency. Results also indicate that some industries have experienced remarkable changes in their levels of agglom- eration in the period 1996–2.04.

关键词： industrial agglomeration manufacturing industries the MS index

Wet-chemical synthesis and characteristics of Au nanoshell

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Science China Chemistry 2005年第5期48卷 431-435页

作者： LIU Zhongxin1,2. SONG Hongwei1, YU Lixin1,2. YANG Linmei1,2.& PAN Guohui1,2.1. Key Laboratory of Excited State Physics, Changchun Institute of Optics, Fine Mechanics and Physics, chinese academy of sciences, Changchun 13.03., China 2. graduate School of the chinese academy of sciences,{3., China 1. Key Laboratory of Excited State Physics Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences 130033 Changchun China 2. graduate School of the chinese academy of sciences 100039 Beijing China

Gold nanoshells were prepared by an easy wet-chemical method, with Ag nanoparticles used as the templates. Transmission electron microscopy (TEM) indicated that the shells were sphere in shape, the size was homogenous, being about 2. nm, and no hard ag-glomerates were observed. The plasma resonance absorption of gold was tuned from visible to near-infrared (NIR) with the increased volume of HAuCl4. The temperature grads (?T) of the gold nanoshell hydrosol under the exposure of an 808-nm optical fiber laser with different power den-sities were measured. The highest ?T was 3.℃ (5 W/cm2. irradiation area was 2.cm2.. This kind of gold nanoshell hydrosol is a promising material to be used in biomedicine such as photo-thermal cancer therapy, and its special photothermal convert property will photothermally trigger drug release.

关键词： wet-chemical synthesis, Au, nanoshell, NIR absorption, photothermal conversion.

Wind vector retrieval using dual polarization imagery of ASAR

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Progress in Natural Science:Materials International 2006年第11期16卷 1183-1187页

作者： SONG Guiting~ 1,2., HOU Yijun~1** and QI Peng~1(1. Institute of Oceanology, chinese academy of sciences, Qingdao 2.6071, China 2. graduate School, chinese academy of sciences,{3., China) [a]Institute of Oceanology Chinese Academy of Science Qingdao China [b]graduate School Chinese Academy of Sciences Beijing China

A new algorithm for retrieving wind vector using dual polarization imagery of advanced synthetic aperture radar (ASAR) is developed and tested. Based on the combination of co-polarization and cross-polarization, this new algorithm effectively eliminates the 180° ambiguity which occurs when using single imagery of the ASAR to retrieve wind vector. This algorithm also solves the problem that the retrieval results will break down on very small spatial scales. The results retrieved from dual polarization imagery of ASAR show that the wind speed and direction are in agreement with the data from Quikscat and buoy measurements. The root mean square errors of wind direction and speed between the retrieved results and data from Quikscat are 2.2.° and 0.53.m/s, respectively. Comparisons between the new method and the traditional method show that the new methods fit the buoy data and Quikscat data a little better than the traditional method in this image.

关键词： wind vector retrieval ASAR dual polarization.

Experimental investigation and numerical simulation on the effect of fissure water pressure in vertical sliding surface

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Science China(Technological sciences) 2005年第z1期48卷 53-64页

作者： ZHANG Lei1,2. LI Shihai1, LIAN Zhenzhong1,2.& WANG Yuannian1 1. Institute of Mechanics, chinese academy of sciences, {3. 100080, China 2. {2. School, chinese academy of sciences, {3. 100060, China 1. Institute of Mechanics Chinese Academy of Sciences 100080 Beijing China 2. graduate School Chinese Academy of Sciences 100060 Beijing China

This paper studies the effect of fissure water pressure in different fractures on the critical angle of landslide by laboratory investigation and numerical simulation in order to understand the mechanisms of fissure water pressure on landslide stability. Laboratory observations show that the effect of fissure water pressure on the critical angle of landslide is little when the distance between water-holding fracture and slope toe is three times greater than the depth of fissure water. These experimental results are also simulated by a three-dimensional face-to-face contact discrete element method. This method has included the fissure water pressure and can accurately calculate the critical angle of jointed slope when fissure water pressure in vertical sliding surface exists. Numerical results are in good agreement with experimental observations. It is revealed that the location of water-holding structural surface is important to landslide stability. The ratio of the distance between water-holding fissure and slope toe to the depth of fissure water is a key parameter to justify the effect of fissure water pressure on the critical angle of landslide.

关键词： jointed rock slope, discrete element method, fracture in vertical sliding surface, model experiment,fissure water pressure.

Inertial theory of the mean Hadley circulation under the condition of nonstatic equilibrium

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Science China Earth sciences 2006年第5期49卷 546-553页

作者： CHAO Jiping1 & LIU Fei2.3.1. National Marine Environmental Forecasting Center, beijing 100081, China 2. Key Laboratory Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics,{3., beijing 10002., China 3. {3. University of{3., beijing 100049, China 1. National Marine Environmental Forecasting Center Beijing 100081 China 2. Key Laboratory Regional Climate-Environment for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 3. graduate University of chinese academy of sciences Beijing 100049 China

Tropical atmosphere is divided into two layers, the layer near the ground is the planet boundary layer, where the motion is linear, if the radiation equilibrium temperature is given at the top of the boundary layer, the vertical motion there can be obtained. It is the non-viscous ideal atmos- pheric layer above the boundary one, where the motion is nonlinear. After getting the conservation laws of angular momentum, potential temperature and potential vortex, the inertial theory of the Hadley circulation driven by the vertical motion of the boundary layer is established, followed by sev- eral examples of its application.

关键词： Hadley circulation, inertial theory, conservation laws of angular momentum, potential temperature and potential vortex.

Physical mechanisms of plant roots affecting weathering and leaching of loess soil

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Science China Earth sciences 2006年第9期49卷 1002-1008页

作者： LI Yong1,2. ZHANG Qingwen1,2. WAN Guojiang3. HUANG Ronggui3. PIAO Hechun3. BAI Lingyu2.& LI Lu2.1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, chinese academy of sciences, Yangling 712.00, China 2. Institute of Agro-Environment and Sustainable Development, chinese {2. of Agricultural {3., beijing 100081, China 3. Institute of Geochemistry, chinese academy of sciences, Guiyang 550002. China 1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences Yangling 712100 China 2. Institute of Agro-Environment and Sustainable Development Chinese Academy of Agricultural Sciences Beijing 100081 China 3. Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

Plant roots have potential impacts on soil mineral weathering and *** objective is to understand the physical mechanisms of plant roots affecting weathering andleaching of loess soil. Root densities were measured through the method of a large-size dug profile,and transport fluxes of soil elements were determined using an undisturbed monolith soilinfiltration device on the hilly and gully regions of the chinese Loess Plateau. The results showthat the improvement effects of soil environment by plant roots are mainly controlled by the densityand weight of the fibrous roots with the diameters less than 1 mm. Plant roots have the strongereffects on soil physical properties than chemical properties. The principal components analysis(PCA) indicates that soil physical properties by plant roots account for 56.7% of variations in soilenvironment whereas soil chemical properties and pH contribute about 2..2. of the soil *** roles of plant roots in controlling soil weathering and leaching increased in the followingorder: infiltration enhancement > increase of bio-active substance > stabilization of soilstructure. The effects of plant roots on soil mineral weathering and leaching can be quantifiedusing the multiple regression models with the high prediction accuracies developed in this study.

关键词： plant roots, soil weathering and leaching rates, soil environment field, principal components analysis (PCA), chinese Loess Plateau.

Formal analysis and design of multi-party fair exchange protocols

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Science in China(Series F) 2006年第2期49卷 155-174页

作者： QING Sihan1,2.3.& LI Gaicheng1,3.1. Engineering Research Center for Information Security Technology, Institute of Software, chinese academy of sciences, beijing 100080, China 2. beijing Zhongke Ansheng Corporation of Information Technology, beijing 100080, China 3. graduate School of the chinese academy of sciences, beijing 10003., China 1. Engineering Research Center for Information Security Technology Institute of Software Chinese Academy of Sciences Beijing 100080 China 2. beijing Zhongke Ansheng Corporation of Information Technology Beijing 100080 China 3. graduate School of the chinese academy of sciences Beijing 100039 China

Based on the origin of message items and channel combination between transacting parties, and events and relations among events, this paper presents a concise, precise, and hierarchical model for general fair exchange protocols, formally specifies various security requirements which are able to reflect inherent requirements for fair exchange protocols more rigorously, and partition these security requirements with fine granularity. This work helps analyze, debug, and design multi-party fair exchange protocols more effectively and elaborately,

关键词： fair exchange logical protocol formal model security requirement.

Cloning and characterization of interferon stimulated genes Viperin and ISG15,and their promoters from snakehead Channa argus

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Progress in Natural Science:Materials International 2007年第12期17卷 1425-1435页

作者： Jia Weizhang1,2. Zhou Xiuxia1,2. Huang Rong1,2.and Guo Qionglin1(1. Institute of Hydrobiololgy,{3., Wuhan 43.072. China 2. graduate University of{3.,{3., China) Institute of Hydrobiololgy Chinese Academy of Sciences Wuhan 430072 China graduate University of chinese academy of sciences Beijing 100039 China

By suppression subtractive hybridization, rapid amplification of cDNA ends and gene walking methods, interferon stimulated genes (ISGs), Viperin and ISG15, and their promoters have been cloned and characterized from snakehead Channa argus. The Viperin cDNA was found to be 1474 nt and contain an open reading frame (ORF) of 1059 nt that translates into a putative peptide of 3.2.amino acid (aa). The putative peptide of Viperin shows high identity to that in teleosts and mammals except for the N-terminal 70 aa. The ISG15 cDNA was found to be 758 nt and contain an ORF of 468 nt that translates into a putative peptide of 155 aa. The putative peptide of ISG15 is composed of two tandem repeats of ubiquitin-like (UBL) domains, and a canonical conjugation motif (LRGG) at C-terminal. Viperin and ISG15 promoter regions were characterized by the presence of interferon stimulating response elements (ISRE) and γ-IFN activation sites (GAS). ISRE is a feature of IFN-induced gene promoter and partially overlaps interferon regulatory factor (IRF) 1 and IRF2.recognition sites. GAS is responsible for the γ-IFN mediated transcription. One conserved site for NF-κB was found in the promoter region of Viperin. This is the first report of conservative binding motif for NF-κB in accordance with the consensus sequence (GGGRNNYYCC) among teleost ISG promoters. Moreover, there were also TATA, CAAT and Sp1 transcription factor sites in Viperin and ISG15 promoters. In 5′ untranslated region (UTR), snakehead ISG15 gene contains a single intron, which differs from Viperin gene. The transcripts of Vipeirn and ISG15 mRNA were mainly expressed in head kidney, posterior kidney, spleen and gill. The expression levels in liver were found to increase obviously in response to induction by IFN-inducer poly I∶C.

关键词： interferon interferon stimulated gene (ISG) Viperin ISG15 snakehead (Channa argus).