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Computational theory of cavitating flows for hydraulic turbomachinery with consideration of influence of water quality

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Science China(Technological Sciences) 2010年第12期53卷 3341-3348页

作者： WANG Lei1,2.& CHANG JinShi2.1 Huadian Electric Power Research Institute, Hangzhou 310030, China 2.college of Water Conservancy and Civil Engineering, China agricultural {2., beijing 100083, China 1. Huadian Electric Power Research Institute Hangzhou 310030 China2. College of Water Conservancy and Civil Engineering China Agricultural University Beijing 100083 China

Previously it was assumed that the pressure within the cavity or on the cavity surface remained constant and the vapor pressure of clean water at 2.°C and 0 m altitude was utilized as the computational boundary for cavitating flows in hydraulic turbomachinery. Cavitation was confused with vaporization, and the effect of water quality on cavitation pressure characteristics was not taken into account. In recent years, lots of experiments of cavitation pressure characteristics of different water qualities including different sand concentrations of sand water and different altitudes of clean water have been performed by the authors, and the important influences of water quality on cavitation pressure characteristic have been validated. Thus the water quality should be involved in the cavitating flows computation. In the present paper, the effect of water quality on the cavitation pressure characteristic is analyzed and the computational method and theory of cavitating flows for hydraulic turbomachinery that considers the influence of water quality are proposed. The theory is suitable for both the potential flow method and the two-phase flow method for cavitating flows simulation. Finally, the validation results for cavitating flows in a hydraulic tur- bine indicate the significant influences of water quality on the cavitating flow performance.

关键词： cavitating flows cavitation pressure water quality hydraulic turbomachinery

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Factors governing formation of todorokite at atmospheric pressure

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Science China Earth Sciences 2005年第10期48卷 1678-1689页

作者： CUI Haojie1, FENG Xionghan1, LIU Fan1, TAN Wenfeng1 & HE Jizheng2.1. college of Resources and Environment, Huazhong agricultural {2., Wuhan 430070, China 2. Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, beijing 100085, China college of Resources and Environment Huazhong agricultural {2. Wuhan China Research Center for Eco-environmental Sciences Chinese Academy of Sciences beijing China

Todorokite commonly occurs in Earth surface environments. The factors governing formation of todorokite, such as reaction temperature, metal ions, dissolved O2.and pH, were investigated in this paper. Results showed that the forming rate of todorokite and its crystallinity decreased with falling reaction temperature, and the effect of temperature was more significant than that of other parameters. Nature of metal ions in the interlayer of buserite precursor and the structure of the buserite precursor obviously affected buserite transformation into todorokite. Weak bonding between the metal ions and MnO6 layer of buserite was favorable to todorokite formation. The rate of todorokite formation was promoted at a lower temperature with appropriate bubbling of O2. The pH in the system slightly influenced the todorokite formation, and todorokite could also be formed in a weak alkali medium or in a slightly acidic medium. Aged buserite pre-cursor more easily form todorokite than the unaged one.

关键词： todorokite, buserite, manganese oxide mineral, atmospheric pressure, transformation.

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Molecular Cloning of a Cytosolic G6PDH Gene from Populus Suaveolens and Its Expression to Improve the Cold Resistance of Tobacco Plants

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冰川冻土 2009年第6期31卷 1178-1185页

作者： LIN Yuan-zhen1,2.GUO Hai3,ZHANG Zhi-yi2.LIN Shan-zhi2.(1. college of Forestry,South China agricultural {2.,Guangzhou Guangdong 510642.China 2. Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants,MOE,beijing Forestry {2.,beijing 100083,China 3. Plant Materials Center for Soil and Water Conservation,Ministry of Water Resources,beijing100038,China) college of Forestry South China Agricultural University Guangdong Guangzhou 510642 Plant Materials Center for Soil and Water Conservation Ministry of Water ResourcesChina Beijing 100038 beijing Forestry university Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental PlantsMOE Beijing 100083 beijing Forestry university Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental PlantsMOE Beijing 100083

Glucose-6-phosphate dehydrogenase (G6PDH,EC 1.***.1.49) is the first and main regulated enzyme of oxidative pentose phosphate pathway (OPPP),catalyzing the conversion of glucose-6-phosphate to 6-phospho-gluconolactone and playing important roles in the growth and development of plants. It is preciously reported that the enhancement of freezing resistance of Populus suaveolenscuttings is clear related to the distinct increase in cytosolic G6PDH activity. Here,a 1697 bp cDNA fragment (PsG6PDH) is amplified by RT-PCR from cold-induced total RNA of the freezing-tolerant P. suaveolens. A sequence analysis showed that PsG6PDH coding region had 1 530 bp and encoded 510 predicted amino acid residues. Genomic Southern analysis revealed that the isoform is encoded by a few copies of the gene in the poplar genome. The cloned gene PsG6PDHis cloned into binary vector pBI12. and used to transform tobacco. PCR and Southern blotting results verified integration of this gene into the genome of tobacco. Moreover,cold treatment experiments and membrane defense enzymeactivity analysis confirmed that overexpression of the PsG6PDHgene could enhance the tolerance to cold or frigid stresses in transgenic plants.

关键词： Populus suaveolens glucose-6-phosphate dehydrogenase cold resistance gene engineering

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Preparation of recombinant firefly luciferase by a simple and rapid expression and purification method and its application in bacterial detection

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Journal of Pharmaceutical Analysis 2010年第2期22卷 97-101页

作者： Qin Xiao1,2.Hui Chen2.Jin-Ming Lin2.1. college of Ocean,Hebei agricultural {2.,Qinhuangdao 066003 2. The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology,Department of Chemistry,Tsinghua {2.,beijing 100084,China. college of Ocean Hebei Agricultural University Qinhuangdao 066003 China Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology Department of Chemistry Tsinghua University Beijing 100084 China

A simple and rapid expression and purification method of recombinant firefly luciferase was developed for bacteria detection. A modified luciferase gene from North American firefly Photinus pyralis was cloned into pET2.a expression vector and the recombinant protein was produced in Escherichia coli BL2.. The recombinant luciferase,equipped with a polyhistidine affinity tag,was purified by immobilized metal ion affinity chromatography (IMAC). The approach generated an abundant expression and an efficient purification of a recombinant luciferase with final yield 1.995mg/L of cell culture. Experiments on the recombinant luciferase also showed that the relative light units (RUL) of the enzyme were 5.8×108,and the specific activity was 2.9×1010 RLU/mg. By applying adenosine triphosphate (ATP) bioluminescence to detection of the coin bacteria using the recombinant protein,the ATP content of bacteria was 9.48×10-16mol/mL,and was identical to the bacteria counts (4500CFU/mL) in order of magnitude. Taken together,our results provided a simple and efficacious method of the preparation of recombinant luciferase,which could be applied in the determination of bacteria via ATP bioluminescence.

关键词： ATP bioluminescence bacterial detection expression firefly luciferase purification

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Generation of fad2.transgenic mice that produce omega-6 fatty acids

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Science China(Life Sciences) 2009年第11期52卷 1048-1054页

作者： CHEN Qing1, LIU Qing2. WU ZhiFang1, WANG ZongYi3 & GOU KeMian1 1 State Key Laboratory for Agrobiotechnology, China agricultural university, {2. 100193, China 2.Blackmountain Laboratory, CSIRO Plant Industry, Canberra, Australia 3 college of Animal Science and Technology, China agricultural university, {2. 100193, China 1. State Key Laboratory for Agrobiotechnology China Agricultural University Beijing 100193 China 2. Blackmountain Laboratory CSIRO Plant Industry Canberra Australia 3. college of Animal Science and Technology China Agricultural University Beijing 100193 China

Fatty acid desaturase-2.(FAD2. introduces a double bond in position 12.in oleic acid (18:1) to form linoleic acid (18:2.n-6) in higher plants and microbes. A new transgenic expression cassette, containing CMV promoter/fad2.cDNA/SV40 polyA, was constructedto produce transgenic mice. Among 63 healthy offspring, 10 founders (15.9%) integrated the cotton fad2.transgene into their genomes, as demonstrated by PCR and Southern blotting analysis. All founder mice were fertile and heterozygous fad2.female and nontransgenic littermates were used for fatty acid analysis using gas chromatography. One fad2.transgenic line showed substantial differences in the fatty acid profiles and the level of linoleic acid was increased 19% (P2.:4 n-6) in muscles and liver, compared to their nontransgenic littermates. The results indicate that the plant fad2.gene can be functionally expressed in transgenic mice and may playan active role in conversion of oleic acid into linoleic acid.

关键词： fatty acid desaturase FAD2 transgenic mouse oleic acid linoleic acid arachidonic acid

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Land cover changes based on plant successions: Deforestation, rehabilitation and degeneration of forest in the upper Dadu River watershed

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Science China Earth Sciences 2005年第12期48卷 2214-2230页

作者： YAN Jianzhong1,2.3, ZHANG Yili1, BAI Wanqi1, LIU Yanhua4, BAO Weikai5, LIU Linshan1, 2.& ZHENG Du1 1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, beijing 100101, China 2. Graduate School of the Chinese Academy of Sciences, beijing 100039, China 3. {2. of Resources and Environment, Southwest agricultural university, Chongqing 400716, China 4. The Ministry of Science and Technology, P. C. China, beijing 100862. China 5. Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China 1. Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. Graduate School of the Chinese Academy of Sciences 100039 Beijing China 3. college of Resources and Environment Southwest Agricultural University 400716 Chongqing China 4. The Ministry of Science and Technology P. C. China 100862 Beijing China 5. Chengdu Institute of Biology Chinese Academy of Sciences 610041 Chengdu China

To link regional land use/cover changes with environmental effects, land cover changes are required to reflect vegetation successions, whereas the land cover classification systems commonly used nowadays cannot serve this purpose. In this paper, a new land cover classification system is established in which land covers are classified by the vegetation succes-sions, taking Zamtang County, Barkam County and Jinchuan County in the upper Dadu River watershed as a study area. Using multi-temporal remote sensing images, the land cover data of 1967, 1986 and 2.00 are obtained by means of integration of unsupervised classification and visual interpretation methods. The database facilitates the study of land use/cover changes, en-vironmental effects and ecological construction. Land cover changes reflect the main ecological processes in the upper Dadu River watershed. The landscape composed mainly of grasslands, wildwoods and alpine scrubs in 1967 was changed to that of grasslands, secondary forests, al-pine scrubs, fragmentary wildwoods, artificial forests, secondary scrubs in 2.00, meanwhile, the landscape got more fragmentized. The total area of the forests decreased by 9.43%. Study results have shown the process of restoration of logged areas in forest centers. From 1967 to 2.00, only 6.86 percents of logged areas were converted to shrubs, meadows or crop-lands, and the rest were converted into artificial forests or secondary forests. So the ecological shelter functions will be restored, stage by stage. Firewood collection, charcoal production and overgrazing are the three major triggers for the extensive degradation of alpine oak forests, Sa-bina tibetica forests and meadows. The arid valley grasslands expanded too. The degradation of vegetation in the southern slopes impairs ecological shelter functions and affects livelihood of local residents, so it is essential to find effective measures for ecological restoration and recon-struction. Field investigations have found

关键词： land use/cover classification, upper Dadu River watershed, vegetation successions, GIS, RS.

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Comparison of the influence factors on NDVI for CCD camera and WFI imager on CBERS-02

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Science China(Technological Sciences) 2005年第S2期48卷 100-115页

作者： YU Tao1,3, LI Xiaoying1,2.3, ZHANG Yong1,2.3, ZHAO Feng1,2.3, GU Xingfa1,3,4, ZHU Li1,2.3, WANG Pengxin5 & MIN Xiangjun6 1. State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Application, CAS, Bei- jing 100101, China 2. Graduate university of Chinese Academy of Sciences, beijing 100039, China 3. The Center for National Spaceborne Demonstration, beijing 100101, China 4. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 5. college of Information and Electrical Engineering, China agricultural university, beijing 100083, China 6. China Center for Resource Satellite Data and Application, beijing 100830, China 1. State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Application CAS 100101 Beijing China 2. The Center for National Spaceborne Demonstration 100101 Beijing China 3. Graduate university of Chinese Academy of Sciences 100039 Beijing China 4. Institut National de la Recherche Agronomique Climat Sol Environnent 84914 Avignon France 5. college of Information and Electrical Engineering China Agricultural University 100083 Beijing China 6. China Center for Resource Satellite Data and Application 100830 Beijing China

CCD and WFI are payloads in the visible light and near infrared bands on CBERS satellites and they have not been applied widely, especially WFI. This article mainly probes into the potential of these two sensors’ application in the vegetation monitoring and analyses the influences of radiometric calibration, atmosphere conditions and sun-observing geometry, etc. on NDVI obtained from these two sensors respectively. In addition it analyses the effect of the spectral response difference of red and near infrared spectral bands in CCD and WFI sensors on NDVI. Results indicate that radiometric calibration is the most important factor on NDVI, which cannot be applied to vegetation monitoring without radiometric calibration. Results also demonstrate that near surface NDVI is different greatly from that of TOA which change with atmosphere conditions. The study shows that NDVI is also affected by the non-lambertian character of surface and the change of the atmospheric path with the observing geometry. And NDVI of WFI is higher than that of CCD. They are very different because of their spectral difference, but they have a good linear relevant relationship.

关键词： CCD WFI NDVI LAI.

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Analysis of China’s Water Security and Virtual Water Trade

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Chinese Journal of Population,Resources and Environment 2006年第4期4卷 18-23页

作者： Wang Hongrui1,2.Liu Xinghan3,Dong Yanyan1,2.Wang Junhong1,2.1.college of Water Sciences,beijing Normal {2.,beijing 100875,China 2.Key Laboratory for Water and Sediment Sciences Ministry of Education,beijing 100875,China 3.college of Economics&Management,beijing {2. of Technology,beijing 10002.,China college of Water Sciences Beijing Normal University Beijing 100875 China Key Laboratory for Water and Sediment Sciences Ministry of Education Beijing 100875 China college of Economics & Management Beijing University of Technology Beijing 100022 China College of Water Sciences Beijing Normal University Beijing 100875 China Key Laboratory for Water and Sediment Sciences Ministry of Education Beijing 100875 China college of Water Sciences Beijing Normal University Beijing 100875 China Key Laboratory for Water and Sediment Sciences Ministry of Education Beijing 100875 China

Producing goods and services all needs water *** water used in the process of an agricultural or industrial product is called the"Virtual Water"contained in this product. Through international trade,water-scarce countries and regions could purchase water-intensive products--especially foods,from water-rich countries to balance their water deficits and achieve water *** is one of the 13 most water-deficit countries whose water safety have been severely *** paper generalized the recent global research development and made a brief introduction about the methods calculating virtual water content in specific *** a case study,we qualified China's annual virtual water flows from year 2.00 to 2.02.with trade in crops,and ended with some policy advice for application and practice of virtual water strategy.

关键词： water security virtual water virtual water trade crops

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A Genome-wide Functional Characterization of Arabidopsis Regulatory Calcium Sensors in Pollen Tubes

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Journal of Integrative Plant Biology 2009年第8期51卷 751-761页

作者： Liming Zhou1,2. Ying Fu1,2.and Zhenbiao Yang2.3 (1State Key Laboratory of Plant Physiology and Biochemistry, Department of Plant Sciences, college of Biological Sciences, China agricultural {2., beijing 100193, China 2.hina agricultural {2. (CAU)-{2. of California, Riverside (UCR) Joint Center for Biological Sciences and Biotechnology, college of Biological Sciences, China agricultural {2., beijing 100193, China 3Center for Plant Cell Biology and Department of Botany and Plant Sciences, {2. of California, Riverside, CA 92.2., USA) ( State Key Laboratory of Plant Physiology and Biochemistry Department of Plant Sciences College of Biological Sciences China Agricultural University Beijing 100193 China China agricultural university (CAU)-university of California Riverside (UCR) Joint Center for Biological Sciences and Biotechnology College of Biological Sciences China Agricultural University Beijing 100193 China Center for Plant Cell Biology and Department of Botany and Plant Sciences University of California Riverside CA 92521 USA)

Calcium, an ubiquitous second messenger, plays an essential and versatile role in cellular signaling. The diverse function of calcium signals is achieved by an excess of calcium sensors. Plants possess large numbers of calcium sensors, most of which have not been functionally characterized. To identify physiologically relevant calcium sensors in a specific cell type, we conducted a genome-wide functional survey in pollen tubes, for which spatiotemporal calcium signals are well-characterized and required for polarized tip growth. *** members of calrnodulin （CAM）, CaM-like （CML）, calcium-dependent protein kinase （CDPK） and calcineurin B-like protein （CBL） families were tagged with green fluorescence protein （GFP） and their localization patterns and overexpression phenotypes were characterized in tobacco pollen tubes. We found that several fusion proteins showed distinct overexpression phenotypes and subcellular localization patterns. CDPK2.-GFP was localized to the vegetative nucleus and the generative cell/sperms. CDPK32.GFP caused severe growth depolarization. CBL2.GFP and CBL3-GFP exhibited dynamic patterns of subcellular localization, including several endomembrane compartments, the apical plasma membrane （PM）, and cytoskeleton-like structures in pollen tubes. Their overexpression also inhibited pollen tube elongation and induced growth depolarization. These putative calcium sensors are excellent candidates for the calcium sensors responsible for the regulation of calcium homeostasis and calciumdependent tip growth and growth oscillation in pollen tubes.

关键词： Arabidopsis calcium sensor calcium signaling Rho-related GTPase from plants subcellular localization tip growth

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Mesh theory of angle modified dual tori double-enveloping toroidal worm drive

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Science China(Technological Sciences) 2010年第7期53卷 1913-1927页

作者： ZHAO YaPing1, SU DaiZhong2. ZHANG Zhao1, WEI WenJun3 & DONG XueZhu3 1 college of Machinery and Automation, Wuhan university of Science and Technology, Wuhan 430081, China 2.Advanced Design and Manufacturing Engineering Center, Nottingham Trent university, Nottingham NG1 4BU, UK 3 college of Engineering, China agricultural university, beijing 100083, China 1. college of Machinery and Automation Wuhan University of Science and Technology Wuhan 430081 China2. Advanced Design and Manufacturing Engineering Center Nottingham Trent University Nottingham NG1 4BU UK3. College of Engineering China Agricultural University Beijing 100083 China

In this paper, the meshing theory of the angle modified hourglass worm drive is enriched and developed. The ordinary condition of the angle modification is derived and the physical significance of the modification is interpreted. A normal section methodology is proposed for meshing analysis, which can be used to compute the normal distance near a singular meshing point of a conjugate surface couple. By means of the method and after analyzing the normal transversals, it is specified that the worm helicoid, the nominal former contact zone and the new contact zone intersect each other along the locus of singular points of the instantaneous contact lines of an angle-modified worm pair. As a result, it is explained clearly that those three osculate each other but the osculations are different in degree. Moreover, the mechanism of removing the twice-contacted zone from the worm gear tooth surface is clarified and the reason of shortening the worm working length is also elucidated. With the help of the theory described in the present paper and the thorough and systematic research on the relevant meshing characteristics, the angle modified dual tori double-enveloping toroidal worm drive has been shown to be an excellent new-fashioned hourglass worm set.

关键词： hourglass worm angle modification double-enveloping osculation normal transversal

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