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Explicit analytical solutions of the anisotropic Brinkman model for the natural convection in porous media(Ⅱ)

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Science China(Physics,Mechanics & Astronomy) 2005年第4期48卷 422-430页

作者： CAI Ruixian1. GOU Chenhua1. 2.& ZHANG Na1.1. Institute of Engineering Thermophysics, {1. {1. of {2., beijing 1.0080, China 2. graduate School, {1. {1. of {2., beijing 1.0080, China 1. Institute of Engineering Thermophysics Chinese Academy of Sciences 100080 Beijing China 2. {1. School Chinese Academy of Sciences 10080 Beijing China

Some algebraically explicit analytical solutions are derived for the anisotropic Brinkman model―an improved Darcy model―describing the natural convection in porous media. Besides their important theoretical meaning (for example, in analyzing the non-Darcy and anisotropic effects on the convection), such analytical solutions can be the benchmark solutions that can promote the development of computational heat and mass transfer. Some solutions considering the anisotropic effect of permeability have been given previously by the authors, and this paper gives solutions including the anisotropic effect of thermal conductivity and the effect of heat sources.

关键词： explicit analytical solution, porous medium, natural convection, Brinkman model, anisotropic.

Algebraically explicit analytical solu-tions for the unsteady non-Newtonian swirling flow in an annular pipe

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Science China(Physics,Mechanics & Astronomy) 2006年第4期49卷 396-400页

作者： CAI Ruixian1.& GOU Chenhua1.2.1. Institute of Engineering Thermophysics, {1. {1. of {2., beijing 1.0080, China 2. graduate School, {1. {1. of {2., beijing 1.0080, China 1. Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100080 China 2. {1. School Chinese Academy of Sciences Beijing 100080 China

This paper presents two algebraically explicit analytical solutions for the incompressible unsteady rotational flow of Oldroyd-B type in an annular pipe. The first solution is derived with the common method of separation of variables. The second one is deduced with the method of separation of variables with addition developed in recent years. The first analytical solution is of clear physical meaning and both of them are fairly simple and valuable for the newly developing computational fluid dynamics. They can be used as the benchmark solutions to verify the applicability of the existing numerical computational methods and to inspire new differencing schemes, grid generation ways, etc. Moreover, a steady solution for the generalized second grade rheologic fluid flow is also presented. The correctness of these solutions can be easily proven by substituting them into the original governing equation.

关键词： analytical solution, Oldroyd-B type fluid, swirling flow, non-Newtonian.

Research on the method for retrieving soil moisture using thermal inertia model

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Science China Earth sciences 2006年第5期49卷 539-545页

作者： LIU Zhenhua1.& ZHAO Yingshi2.1. Information College, South China Agricultural {1., Guangzhou 51.642. China 2. graduate university of chinese academy of sciences,{2., China 1. Information College South China Agricultural University Guangzhou 510642 China 2. graduate university of chinese academy of sciences Beijing 100049 China

In order to improve accuracy of soil moisture inversion using remote sensing, a new thermal inertia model is proposed in this paper. The improved model needs only surface maximum temperature as the temperature parameter input instead of input of the surface temperature difference, as well as the surface sensible and latent fluxes are introduced into boundary conditions of thermal conductivity equation. Furthermore, surface soil conductive heat transfer equation of two-layer model is used to solve the soil thermal inertia so that the remote sensing thermal inertia method can be ap- plied to regions with better-covered vegetation, but usually only for the bare areas or worse vegetation covered areas. The model has been tested at several locations in the area of west Inner Mongolia. Comparing the simulation of the new model with the measurements obtained by apparent thermal inertia and by field test, the result shows that the inertia thermal model can be used to estimate soil moisture in more reasonable accuracy.

关键词： thermal model, thermal conductivity equation, soil initial, sensible flux, latent flux, two-layer model.

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 {1. of {2., Qingdao 2.6071, China 2. graduate School, chinese {1. of {2., beijing 100039, 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 1.0° 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.

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, {1. {1. of {2., beijing 1.0080, China 2. graduate School of the {1. {1. of {2., beijing 1.0039, China 1. Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China 2. {1. School of the {1. {2. 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 (Instron3365), 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 356 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.

Cloning and characterization of interferon stimulated genes Viperin and ISG1.,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, chinese {1. of {2., Wuhan 430072. China 2. graduate university of chinese academy of sciences, beijing 1.0039, China) Institute of Hydrobiololgy Chinese Academy of Sciences Wuhan 430072 China graduate{1. of {2. 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 ISG1., and their promoters have been cloned and characterized from snakehead Channa argus. The Viperin cDNA was found to be 1.74 nt and contain an open reading frame (ORF) of 1.59 nt that translates into a putative peptide of 352.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 ISG1. cDNA was found to be 758 nt and contain an ORF of 468 nt that translates into a putative peptide of 1.5 aa. The putative peptide of ISG1. is composed of two tandem repeats of ubiquitin-like (UBL) domains, and a canonical conjugation motif (LRGG) at C-terminal. Viperin and ISG1. 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 ISG1. promoters. In 5′ untranslated region (UTR), snakehead ISG1. gene contains a single intron, which differs from Viperin gene. The transcripts of Vipeirn and ISG1. 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 ISG1. snakehead (Channa argus).

Characteristics and geological significance of olivine xenocrysts in Cenozoic volcanic rocks from western Qinling

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Progress in Natural Science:Materials International 2006年第12期16卷 1300-1306页

作者： SU Benxun~ 1.2.**, ZHANG Hongfu~1. XIAO Yan~ 1.2.and ZHAO Xinmiao~ 1.2.(1. State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, chinese {1. of {2., beijing 1.002., China 2. graduate School of chinese {1. of {2., beijing 1.0039, China) [a]State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China [b]graduate School of{1. {2. of sciences Beijing China

Cenozoic volcanic rocks from the Haoti, Dangchang County of the western Qinling Mountains, contain a few clearly-zoned olivines. These olivines are relatively big in grain sizes and usually have cracks or broken features. Their cores have similar compositions （Mg#=90.4-91.0） to those for the peridotitic xenoliths entrained in host volcanic rocks and their rims are close to the compositions of olivine phenocrysts （Mg#=85.5-81.9）. The CaO contents in these zoned olivines are lower than 0.1.. These features demonstrate that the clearly-zoned olivines are xenocrysts and disaggregated from mantle peridotites. The zoned texture was the result of the interaction between the olivine and host magma. Available data show that the volcanic rocks would have been derived from the mantle source metasomatized by subducted hydrathermally-altered oceanic crust. The formation of these Cenozoic volcanic rocks was perhaps related to the rapid uplift of the Tibetan Plateau.

关键词： Western Qinling Dangchang Haoti Cenozoic volcanic rocks olivine xenocrysts zoned texture.

Parentage determination of an isolated Yangtze finless porpoise population Neophocaena phocaenoides asiaeorientalis in the Yangtze Tian-e-Zhou Baiji National Natural Reserve based on molecular data

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Progress in Natural Science:Materials International 2005年第2期15卷 54-61页

作者： XIA Junhong 1,2. ZHENG Jinsong 1,2. XU Limei 1,2.and WANG Ding1*(1. Institute of Hydrobiology, chinese {1. of {2., Wuhan 430072. China 2. graduate School of the chinese {1. of {2., beijing 100039, China) Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China. graduate School of the{1. {2. of sciences Beijing 100039 China

Reproductive behaviors are poorly known for the Yangtze finless porpoise Neophocaena phocaenoides asiaeorientalis. In this study, the parentage of an isolated Yangtze finless porpoise population inhabiting the Yangtze Tian-e-Zhou Baiji National Natural Reserve is determined by analysis of microsatellite loci and mitochondrial DNA (mtDNA) control region sequences, and the porpoise's reproductive behaviors are studied. Overall 4 full parentage assignments and additional 3 single parentage assignments were determined for the population of 2. individuals. The analysis shows that their estimated reproductive cycle is shorter than that reported previously and there probably exists an overlapping between gestation and lactation period. The study also shows that the female does not show fidelity to a particular male for breeding and vice versa, the oldest males did not monopolize mating and the dominance rank could not be so strict for the porpoise society. Moreover, the porpoise's mating pattern and relatedness among candidate parents are discussed here. These results provide important information for making guidelines of management and conservation for this protected population.

关键词： Yangtze finless porpoise isolated population reproductive behavior parentage

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 {1. of {2., beijing 1.0080, China 2. graduate School, chinese {1. of {2., beijing 1.0060, China 1. Institute of Mechanics Chinese Academy of Sciences 100080 Beijing China 2. {1. 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.