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A study on the allocation of productive factors of Chinese agriculture

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Journal of Geographical Sciences 2000年第1期10卷 59-65页

作者： LIU Yan-li (Institute of Rural Development, china agricultural university, Beijing 100094,{2.) 中国农业大学北京

Chinese agriculture is undergoing a transformation process from traditional agriculture into modern *** article discusses how land. labor, fertilizer, machinery etc. are used in agricultural production of different regions. reveals the influence of natural conditions and economic level on the utilization of modern agricultural factors. It proposes a system of allocation hoes of regional agricultural productive factors and points out the development stage and tendency of allocation of agricultural productive factors in different regions.

关键词： agricultural productive factor, innovative productive factor,traditional allocation technological allocation

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 university, Beijing 100193, china 2.2. agricultural university (CAU)-university of California, Riverside (UCR) Joint {6. for Biological Sciences and Biotechnology, College of Biological Sciences, china agricultural university, Beijing 100193, china 3{6. for Plant Cell Biology and Department of Botany and Plant Sciences, university 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 {2. (CAU)-{2. 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

Cloning of a down-regulated gene encoding small GTP binding protein in hybrid wheat

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Progress in Natural Science:Materials International 2005年第7期15卷 621-626页

作者： YAO Yingyin, NI Zhongfu, CHEN Rongmin, WU Limin and SUN Qixin (Department of Plant Genetic & Breeding, State Key Laboratory for Agro-biotechnology, china agricultural university, Beijing 100094,{2.) Department of Plant Genetic & Breeding State Key Laboratory for Agro-biotechnology China Agricultural University Beijing 100094 China

Previous studies showed that differential gene expression between wheat hybrids and their parents was responsible for the heterosis. To provide an insight into the molecular basis of wheat heterosis, one cDNA, designated TaRab, was identified from the cDNA library of wheat seedling leaves. The sequence comparison in GenBank revealed that TaRab is homologous to a group of genes encoding Rab-GTP binding protein. Semi-quantitative RT-PCR analysis indicated that TaRab was expressed in all plant tissues examined, but at slightly higher level in leaves. Further analysis exhibited that TaRab displayed lower expression in hybrid than in its patents in both roots and leaves, which was in agreement with the original results of suppression subtractive hybridization. TaRab was located on chromosome 7B and C-7DS5-0.36.by in silico mapping. The relationship between differential expression of TaRab and the molecular basis of wheat heterosis was also discussed.

关键词： wheat Rab protein gene expression heterosis.

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 university, 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

Ecological rebuilding and land reclamation in surface mines in Shanxi Province, china

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Journal of Environmental Sciences 2000年第4期12卷 486-497页

作者： MIAO Ze wei 1, BAI Zhong ke 2. GAO Lin 1 (1. Research center for Eco Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, china E\|mail: miaozewei@*** 2. Department of Soil Science, Shanxi {2. university Taigu, 03 中科院生态环境研究中心北京 1 0 0 0 85 山西师范大学山西临汾 0 3 0 80 1

It is well known that the mining industry produces a large amount of derelict land, and causes pollution of water loss and soil erosion as well as other environmental damage in china. As land is under pressure in china, it is now policy to restore or reclaim land despoiled by mining, the aim being to develop sustainable and healthy arable land ecosystems. This paper outlines the principles and approaches of ecological restoration, which have been adopted in Shanxi Province with reference to three typical surface mines. In the research, the principles of ecological engineering and ecological succession are considered as the critical theories of ecological restoration in mine degraded land. Meanwhile, the paper made a comparative research on main links of ecological rebuilding in three surface mines in Shanxi Province, which include new land construction, treatment of toxic substances, control of soil erosion, fertility management, irrigation, ecological planning and the establishment of legislation systems. As the research demonstrated, for successful restoration, new land construction is the fundamental framework, but it must be integrated with ecological engineering including ecological planning, the control of soil erosion and vegetation establishment and ecosystem creation in order to optimise land productivity and soil fertility. In addition, the establishment of the legislation systems and organization of administration are also indispensable aspects of ecological rebuilding in mined land.

关键词： ecological restoration land reclamation open-pit mine

Transitional function of DG to CA3 in the hippocampus

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Progress in Natural Science:Materials International 2007年第12期17卷 1436-1444页

作者： Yan Chuankui1 and Liu Shenquan2.1. Department of Mathematics, Hangzhou Normal university, Hangzhou 310036.{2. 2. Department of Applied Mathematics, School of Mathematical Sciences, South{2. university of Technology, Guangzhou 5106.0,{2.) Department of Mathematics Hangzhou Normal University Hangzhou 310036 China Department of Applied Mathematics School of Mathematical Sciences South China University of Technology Guangzhou 510640 China

Using single cell channel model, the transmission features of CA3-DG network in the hippocampus are investigated. The influence of the stimulation on discharge pattern of pyramidal neurons is analyzed, which shows that it starts with period spiking discharges, followed by period-doubling bifurcation to chaos, and period 3 discharge evolving into chaos, and ultimately a period of bursting discharges. By the synaptic model, the CA3-DG network model is constructed, which analyzes the summation of postsynaptic currents in the network, the influence of postsynaptic current on discharge rhythm as well as the mechanism of bursting discharges. The strong capacity of spatiotemporal encoding in the network indicates the features of CA3 network during the information transmission process in the hippocampus. The modeling result with time delay of the synaptic transmission is in accordance with the experimental phenomena of action potential in the hippocampus.

关键词： hippocampus CA3-DG period-doubling bifurcation chaos.

Relationship between differ- ential gene expression pat- terns in functional leaves of maize (Zea mays L.) at milk filling stage and heterosis using cDNA-AFLP

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Chinese Science Bulletin 2003年第1期48卷 76-81页

作者： TIAN Zengyuan & DAI Jingrui National Maize Improvement center of china, china agricultural Uni-versity, Beijing 100094, china Correspondence should be addressed to Tian Zengyuan (e-mail: tian-zengyuan@***) National Maize Improvement center of china China Agricultural University Beijing 100094 China

To understand the molecular mechanism of maize heterosis, differential gene expression patterns in the functional leaves of 35 maize hybrids relative to their parents involving 10 elite inbreds at milk filling stage were analyzed by using cDNA-AFLP. The correlation analyses of various differential expression patterns with the performance and heterosis of main maize agronomic traits were evaluated. The main results were as follows: For uniparental specific expression, significant positive correlations were detected with the performance of seed weight per ear and 100-seed weight at 0.01 and 0.05 probability levels respectively. For biparental specific expression, significant negative correla-tions were detected with the performance of ear diameter and seed weight per ear at 0.01 probability level. For uni-parental specific expression, significant positive correlations were detected with the heterosis of ear diameter and seed weight per ear at 0.01 and 0.05 probability levels respectively. For biparental specific expression, significant negative cor-relation was detected with the heterosis of ear diameter at 0.05 probability level. However, for F1-specific expression, for fragments detected only in one parent and F1, and for fragments detected only in two parents or only in F1, no sig-nificant correlation was detected with the performance or heterosis of all agronomic traits surveyed.

关键词：玉米灌浆期叶片差异基因表达模式杂种优势相关性 cDNA-AFLP 农艺性状

The refined theory of deep rectangular beams for symmetrical deformation

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Science china(Physics,Mechanics & Astronomy) 2009年第6期52卷 919-925页

作者： GAO Yang1 & WANG MinZhong2.1 College of Science, china agricultural university, Beijing 100083, china 2.State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Aerospace Engineering, Peking {2., Beijing 100871, china College of Science China Agricultural University Beijing 100083 China State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Aerospace Engineering Peking University Beijing 100871 China

Based on elasticity theory, various one-dimensional equations for symmetrical deformation have been deduced systematically and directly from the two-dimensional theory of deep rectangular beams by using the Papkovich-Neuber solution and the Lur'e method without ad hoc assumptions, and they construct the refined theory of beams for symmetrical deformation. It is shown that the displacements and stresses of the beam can be represented by the transverse normal strain and displacement of the mid-plane. In the case of homogeneous boundary conditions, the exact solutions for the beam are derived, and the exact equations consist of two governing differential equations: the second-order equation and the transcendental equation. In the case of non-homogeneous boundary conditions, the approximate governing differential equations and solutions for the beam under normal loadings only and shear loadings only are derived directly from the refined beam theory, respectively, and the correctness of the stress assumptions in classic extension or compression problems is revised. Meanwhile, as an example, explicit expressions of analytical solutions are obtained for beams subjected to an exponentially distributed load along the length of beams.

关键词： deep rectangular beams the refined theory symmetrical deformation the Papkovich-Neuber solution the Lur’e method

Biomass of meiobenthic in the Bohai Sea, china

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Acta Oceanologica Sinica 2001年第3期20卷 435-442页

作者： Guo Yuqing, Zhang Zhinan, Mu Fanghong 1. Department of Life Science, Ocean university of Qingdao, Qingdao 2.1}003,{2. 2. agricultural College, jimei university, Xiamen 36.02.,{2. Department of Life Science Ocean University of Qingdao Qingdao 266003 China agricultural College Jimei University Xiamen 361021 China

A grid of 2. stations, giving a broad geographic coverage of the Bohai Sea and the Bohai Strait was selected. Undisturbed sediments were collected from sampling stations during cruises in June 1997, in September/October 1998 and again in April/May 1999. Based on the results of Juario (1975), the average biomass, 0.404 g/(m2.) of meiofauna (including nematode, harpacticoida, bivalve larvae, polycheata and kinorhyncha) in the Bohai Sea is given and accounts for 4.5 percent of the macrofauna in the Bohai Sea. The horizontal distribution of the biomass of meiofauna showed that it was higher at the stations of middle east part of the Bohai Sea and the strait in 1998 and 1999 cruises and it decreased at the stations near to the strait mouth and increased at Station B1 in 1999 cruise. The annual average production in the Bohai Sea is 3.6.6.g/m2.calculated in term of the formula P = 9B. Compared with the biomass of other sea areas in the world, the biomass of the Bohai Sea is similar but slightly lower. The individual average dry weight of nematodes given by different authors is analyzed.

关键词： Meiofauna free-living marine nematodes benthic copepods biomass the Bohai Sea