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Experimental Study of Rat Beta Islet Cells Cultured under Simulated Microgravity Conditions

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Acta Biochimica et Biophysica Sinica 2004年第1期36卷 47-50页

作者： Chun song, Xiu-Qing DUAN, Xi LI, Li-Ou HAN, Ping XU, Chun-Fang song, and Lian-Hong JIN (Key Laboratory of Cell Transplantation of Ministry of Health, First Affiliated Hospital of harbin Medical university, harbin 150001, china Department of General Surgery, First Affiliated Hospital of harbin Medical university, harbin 150001, china National Key Laboratory of harbin Veterinary Research Institute of Chinese Agriculture Academy, harbin 150001, china Tissue engineering Research Center, Histology and Embryology Staff Room, harbin Medical university, harbin 150086, china ) Key Laboratory of Cell Transplantation of Ministry of Health First Affiliated Hospital of Harbin Medical University Harbin 150001 China Department of General Surgery First Affiliated Hospital of Harbin Medical University Harbin 150001 China National Key Laboratory of harbin Veterinary Research Institute of Chinese Agriculture Academy harbin 150001 China Tissue engineering Research Center Histology and Embryology Staff Room Harbin Medical University Harbin 150086 China

To observe the effects of simulated microgravity on beta islet cell culture, we have compared the survival rates and the insulin levels of the isolated rat islet cells cultured at micro- and normal gravity conditions. The survival rates of the cells cultured were determined by acridine orange-propidium iodide double-staining on day 3, 7 and 14. The morphology of the cells was observed by electron microscopy. Insulin levels were measured by radio immuno assays. Our results show that the cell number cultured under the microgravity condition is significantly higher than that under the routine condition (P<0.01). Some tubular structure shown by transmission electron microscopy, possibly for the transport of nutrients, were formed intercellularly in the microgravity cultured group on day 7. There were also abundant secretion particles and mitochondria in the cytoplasm of the cells. Scanning electron microscopy showed that there were holes formed between each islet, possibly connecting with the nutrient trans

关键词： simulated microgravity islet cell electron microscopy radioimmunoassay

High Temperature Tensile Properties of 30 vol. pct ZrCp/W Composite

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Journal of Materials Science & Technology 2003年第2期19卷 167-170页

作者： Yujin WANG, Yu ZHOU, Guiming song and Tingquan LEI School of Materials Science and engineering, harbin Institute of Technology, harbin 150001, china Sch. of Mat. Sci. and Eng. Harbin Inst. of Technol. Harbin 150001 China

In order to improve the high temperature strength of tungsten, 30 vol. pct ZrC particles were added to the tungsten matrix to form a 30ZrCp/W composite. The tensile properties from 20C to 1880C of the composite were examined. It was shown that with increasing testing temperature, the nonlinearity of the stress strain curve of 30ZrCp/W composite becames obvious over 1200C and the Young's modulus decreases and the elongation increases. The ultimate tensile strength increases at first and then decreases with increasing testing temperature. The maximum strength of 431 MPa was obtained at 1000C. The strengthening mechanism at high temperatures is the load transfer to ZrC particles and dislocation strengthening of the tungsten matrix with an effect of grain boundary strengthening.

关键词： ZrCp/W composite Tensile strength High temperature Strengthening mechanism Load transfer Dislocation strengthening

PERTURBATION SOLUTION OF SECONDARY FLOW OF POWER-LAW FLUID IN HELICAL PIPES WITH CIRCULAR CROSS-SECTION

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Journal of Hydrodynamics 2001年第4期13卷 72-78页

作者： Cui Hai-qing, Wang Ke-liang Department of Petroleum engineering, Daqing Petroleum Institute, Anda 151400, china Wu Fu-bing Department of Navy and Ocean engineering, harbin engineering university, harbin 150001, china Zheng Xiao-song Department of Pet Dept. of Petroleum Eng. Daqing Petroleum Inst. Anda 151400 China

In terms of tensor analysis technique, the Navier-Stokes equations in helical coordinate system were derived. A steady incompressible flow of power-law fluid in helical pipes at low Reynolds number was investigated by the perturbation method. A second order solution of secondary flow was worked out. The secondary flow characteristics in helical pipes are analyzed. The effects of the number Dn, curvature and torsion on the secondary flow at different flow parameters were discussed. The results show that the secondary flow pattern changes from a single vortex to two vortices as the number Dn increases at a given curvature and a given torsion. Because of the effect of torsion, the secondary flow pattern changes from two almost symmetrical vortices to a single vortex as the torsion of the helical pipe increases while the Reynolds number and curvature hold constant. The secondary flow pattern cannot be affected by the curvature of the helical pipe at a given Dn number.

关键词： helical pipe secondary flow power-law fluid perturbation method

Enhancing aerodynamic performances of a high-turning compressor cascade via boundary layer suction

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Science china(Technological Sciences) 2010年第10期53卷 2748-2755页

作者： GUO Shuang1, CHEN ShaoWen1, LU HuaWei2, song YanPing1 & CHEN Fu1 1 School of Energy Science and engineering, harbin Institute of Technology, harbin 150001, china 2 Marine engineering College, Dalian Maritime university, Dalian 116026, china 1. School of Energy Science and engineering Harbin Institute of Technology Harbin 150001 China2. Marine Engineering College Dalian Maritime University Dalian 116026 China

Experimental investigation was carried out to study the effect of suction positions and suction flow rates on the aerodynamic performance of a compressor cascade with a large camber angle. The ink-trace flow visualization was conducted and the flow fields of the cascade were also measured. Three types of boundary layer suction configurations are compared,i.e. the suction surface suction,the endwall suction and the compound suction. Experimental results show that the large amount of suction flow rate gains more losses reduction than the small amount for a certain proper suction configuration,but the speed of loss decline slows down as the suction flow rate goes on increasing. Boundary layer suction on the suction surface obviously enhances the ability of the boundary layer around the midspan to withstand the negative pressure gradient of the flow passage. The range of the suction surface corner is also decreased. If the suction slot locates in the corner separation region where severe separation has happened,the flow separation will be terminated at the slot and redevelop downstream. And boundary layer suction on the endwall mainly influences the endwall corner region in remarkably delaying,lessening and reorganizing the corner separation. While the whole flow field is remarkably improved at both midspan and the corner region in the compound suction schemes. At higher suction flow rates,the aerodynamic performance of the compressor cascade is better than that with boundary layer suction simply on the suction surface or on the endwall. When the suction flow rate is 1.5% of the inlet mass flow,the compound suction scheme achieves a maximum loss reduction of 17% compared with the cascade without boundary layer suction.

关键词： boundary layer suction high-turning diffusion cascade suction flow rate suction position experimental investigation

Recent advances in fermentative biohydrogen production

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Progress in Natural Science:Materials International 2008年第3期18卷 253-258页

作者： Xuemei Liu a,b, Nanqi Ren a, Funan song b, Chuanping Yang b, Aijie Wang a a harbin Institute of Technology, harbin 150010, china b Northeast Forestry university, harbin 150040, china harbin Institute of Technology Harbin 150010 China Northeast Forestry university Harbin 150040 China

Hydrogen energy, as a kind of clean energy with great potential, has been a hotspot for study worldwide. Based on the recent research on biohydrogen production, this paper gives a brief review on the following aspects: fermentative hydrogen production process and the engineering control statagy, key factors affecting the effciency of hydrogen production, such as substrates, cysteine, metal ions, anaerobic fermentation terminal products, and formic acid and ammonia. Moreover, anaerobic fermentative hydrogen-producing strain and reg- ulation and control of enzyme gene in fermentative hydrogen production are also discussed. Finally, the prospect of anaerobic fermen- tative biohydrogen production is proposed in three study areas, namely developing new techniques for breeding hydrogen-producing bacteria, exploitations of more strains and gene resources, and intensifying the application of microbial molecular breeding in hydrogen production.

关键词： Fermentation Biohydrogen production Regulation and control Novel strains

Data Hiding and Security for XMLDatabase: A TRBAC-Based Approach

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Wuhan university Journal of Natural Sciences 2005年第1期10卷 293-296页

作者： ZHANGWan-song SUNWei LIUDa-xin SchoolofComputerScienceandTechnology HarbinEngineeringUniversityHarbin150001HeilongjiangChna

In order to cope with varying protection granularity levels of XML(extensible Markup Language) documents, we propose a TXAC (Two-level XML. Access Control) framework,in which an extended TRBAC ( Temporal Role-Based Access Control) approach is proposed to deal withthe dynamic XML data With different system components, LXAC algorithm evaluates access requestsefficiently by appropriate access control policy in dynamic web environment. The method is aflexible and powerful security system offering amulti-level access control solution.

关键词： XML data access control data security

Pictet-Spengler condensation reactions catalyzed by a recyclable H^+-montmorillonite as a heterogeneous BrΦnsted acid

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Science china Chemistry 2010年第3期53卷 561-567页

作者： WANG YuFeng,song ZhanBo,CHEN ChunXia & PENG Jinsong Department of Chemistry and Chemical engineering,College of Science,Northeast Forestry university,harbin 150040,china 1. Department of Chemistry and Chemical engineering College of Science Northeast Forestry University Harbin 150040 China

Catalytic performance of different cation-exchanged montmorillonite clays has been investigated in the Pictet-Spengler C-C bond forming reaction.H+-Montmorillonite was found to be a very efficient and reusable catalyst for the endo cyclization of β-phenylethylamine derivatives with aldehydes under solvent-free *** addition,an aqueous condensation version for the synthesis of tetrahydro-β-carbolines using the H+-montmorillonite catalyst has been *** these environmentally friendly processes,the use of organic solvents was avoided and the catalyst was recycled with maintenance of high catalytic activity.

关键词： heterogeneous catalysis catalyst recycling mesoporous materials green synthesis

The generalized quasi-variational principles of non-conservative systems with two kinds of variables

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Science china(Physics,Mechanics & Astronomy) 2005年第5期 90-103页

作者： LIANG Lifu, LIU Diankui & song Haiyan School of Civil engineering, harbin engineering university, harbin 150001, china

According to the corresponding relations between general forces and general displacements, the balancing and geometrical equations of elasticity are multiplied by the corresponding virtual quantities, integrated with volume and area, and then added algebraically. Proceeding to the next step, by substituting constitutive relation and considering that body force and surface force are both fellow forces, the generalized quasi-variational principles with the two kinds of variables of the first type are established in non-conservative systems. Through substituting another constitutive relation, using similar methods as above, the generalized quasi-variational principles with the two kinds of variables of the second type are established in non-conservative systems. By using the generalized quasi-complementary energy principles with the two kinds of variables of the first type, a method for solving two kinds of variables (internal force and deformation) is given for non-conservative systems of the typical fellow forces.

关键词： non-conservative system generalized variational principle two kinds of variables.

CALCULATION AND TEST RESEARCH OF ADDED MASS OF SLENDER BODIES IN STRAIGHT WATER CHANNEL

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Journal of Hydrodynamics 1991年第1期3卷 16-21页

作者： Yang, song-lin Wang, Tai-shu Zhenjiang Shipbuilding Inst Zhenjiang China

In this paper, a numerical method of calculating added mass coefficients of slender bodies in straight water channels with strip theory is presented. The added mass coefficients of a heaving ellipsoid below the free s... 详细信息

关键词： Computers Applications Equations of Motion Flow of Fluids Channel Flow