Phylogeography of Schizothorax o'connori (Cyprinidae: Schizothoracinae) in the Yarlung Tsangpo River, Tibet

Schizothorax o'connori is endemic to the Yarlung Tsangpo River on the Tibetan Plateau. We assessed the relative impacts of historical and contemporary factors in organizing genetic variation in S. o'connori populations using mitochondrial cytochrome b sequences. We analyzed 191 samples from 11 populations and identified 78 haplotypes. The phylogenetic analyses and analysis of molecular variance all supported the same conclusions of two well-differentiated east-west phylogroups, separated by the Tsangpo Great Gorge. The split between the two clades accounted for 58% of the genetic variance observed among the examined samples. Waterfalls as effective barriers played an important role in shaping the phylogeographical structure of this species. Analyses of migration rates revealed that upstream dispersal was limited crossing waterfalls. Our study revealed substantial spatial and temporal variation in the influence of landscape features on contemporary patterns of genetic structure in S. o'connori. Interglacial range expansions clearly left their mark on contemporary populations above the Tsangpo Great Gorge.

Identification of Prorocentrum minimum and Takayama pulchella by fluorescence in situ hybridization through epifluorescence microscopy and flow cytometry

Partial rDNA sequences of Prorocentrum minimum and Takayama pulchella were amplified, cloned and sequenced. and these sequence data were deposited in the GenBank. Eight oligonucleotide probes (DNA probes) were designed based on the sequence analysis. The probes were employed to detect and identify P. minimum and T. pulchella in unialgal and mixed algal samples with a fluorescence in situ hybridization method using flow cytometry. Epifluorescence micrographs showed that these specific probes labeled with fluorescein isothiocyanate entered the algal cells and bound to target sequences, and the fluorescence signal resulting from whole-cell hybridization varied from probe to probe. These DNA probes and the hybridization protocol we developed were specific and effective for P. minimum and T. pulchella, without any specific binding to other algal species. The hybridization efficiency of different probes specific to P. minimum was in the order: PM18S02 > PM28S02 > PM28S01 > PM18S01, and that of the probes specific to T. pulchella was TP18S02 > TP28S01 > TP28S02 > TP18S01. The different hybridization efficiency of the DNA probes could also be shown in the fluorescent signals between the labeled and unlabeled cells demonstrated using flow cytometry. The DNA probes PM18S02, PM28S02; TP18S02 and TP28S01, and the protocol, were also useful for the detection of algae in natural samples.

Interactions between a cyanobacterial bloom (Microcystis) and the submerged aquatic plant Ceratophyllum oryzetorum Kom.

In aquatic ecosystems, macrophytes and phytoplankton are main primary producers, in which macrophyte plays an important role in maintaining clear water state, while phytoplankton often dominates in turbid waterbodies. In the present study, the growth and photosynthetic activity of the submerged aquatic plant Ceratophyllum oryzetorum Kom. in different cell densities of cyanobacterial bloom are studied. The results show that the plant length and fresh mass of C. oryzetorum are promoted by low cyanobacterial cell densities. Medium and high cyanobacterial cell densities, on the contrary, act as inhibitory. Furthermore, the photosynthetic activity of C. oryzetorum is strongly inhibited by high cyanobacterial cell densities. To a certain extent, the growth of cyanobacteria is inhibited by C. oryzetorum, but no significant effect is found in this study.

The synthesis of astaxanthin esters, independent of the formation of cysts, highly correlates with the synthesis of fatty acids in Haematococcus pluvialis

The compositions and contents of astaxanthin esters and fatty acids in four types of Haematococcus pluvialis cells were studied by HPLC and GC-MS. Results showed that the synthesis and accumulation of astaxanthin was independent of the formation of cysts, but was highly correlated with the synthesis and accumulation of fatty acids, though it is an well known phenomenon that the accumulation of astaxanthin is usually accompanied by the formation of cyst. The red cysts contain more than 30% of fatty acids, with 81% of the unsaturated fatty acids. Taken together, besides a resource of astaxanthin, H. pluvialis would be a good resource of valuable fatty acids.

Temperature-dependent transport and spin accumulation in a quantum wire with Rashba spin-orbit interaction

We study the theory of temperature-dependent electron transport, spin polarization, and spin accumulation in a Rashba spin-orbit interaction (RSOI) quantum wire connected nonadiabatically to two normal conductor electrode leads. The influence of both the wire-lead connection and the RSOI on the electron transport is treated analytically by means of a scattering matrix technique and by using an effective free-electron approximation. Through analytical analysis and numerical examples, we demonstrate a simple way to design a sensitive spin-transfer switch that operates without applying any external magnetic fields or attaching ferromagnetic contacts. We also demonstrate that the antisymmetry of the spin accumulation can be destroyed slightly by the coupling between the leads and the wire. Moreover, temperature can weaken the polarization and smear out the oscillations in the spin accumulation.

Design and characteristics of quantum cascade laser-based CO detection system

National High Technology Research and Development Program of China 2007AA03Z112；Program of Ministry of Education of China 20060183030；Program of Jilin Provincial Science and Technology Department of China 20070709；Program of Bureau of Science and Technology of Changchun City 2007107

基于GIS和CSLE的陕西省土壤侵蚀定量评价方法研究

通过对陕西省土壤侵蚀的定量评估,探索省域尺度上土壤侵蚀定量评价制图方法,以期为第四次全国土壤侵蚀普查提供技术支撑。利用陕西省日降雨数据、土壤类型图、土地利用图、DEM、植被覆盖图,选择CSLE模型,在ArcGIS平台上计算研究区2006年土壤侵蚀量,并与水利部标准评价结果进行对比分析。探索了坡度坡长变换对土壤侵蚀的影响。定量化的评价结果能较好的反映气候、土壤及水保措施对土壤侵蚀的影响,比水利部标准评价结果更能反映实际侵蚀。坡度坡长变换后对土壤侵蚀有明显影响。在GIS支持下,通过土壤侵蚀模型进行定量评价,可高效、客观反映土壤侵蚀情况及其主要影响因子,对区域治理和有关决策有极其重要参考价值。为了准确真实的反映土壤侵蚀程度,必须进行坡度坡长变换。

基于RS和GIS的四川省土地利用/覆盖变化及可持续利用研究

LUCC是全球变化研究的核心主题之一，也是社会经济可持续发展的关键问题。改革开放后四川的社会经济发展非常快，在各种因素的驱动下，土地利用/覆盖发生了深刻变化。目前四川省缺乏基于实际调查数据的、全域性的、具有连续时间序列的LUCC和驱动力分析及土地可持续利用研究成果，这对我们从全局上把握全省土地利用现状、发展变化趋势，利用土地政策参与宏观调控，实现长期可持续发展目标，建设资源节约型、环境友好型社会极为不利。本研究针对这一问题，选取全川八大土地利用类型作为研究对象，研究了全省1996年到2006年的土地利用/覆盖格局和变化情况，分析了不同尺度的驱动因素，对全省农用地和建设用地的集约利用状况、潜力进行了分析评价，并提出相应的对策措施。 1．1996年-2006年10年来整个省域的土地利用/覆盖格局变化。 （1）1996年-2006年全省的土地利用/覆盖格局 1996年，全省是一个以农用地为主的土地利用/覆盖格局，林地和牧草地属于优势覆盖类型（合占69.17%），居民点及工矿用地和交通用地合占只有3%左右。 2000年的LUCC格局较为明显的特点是耕地所占比重下降0.4个百分点，水域和未利用土地所占比重有所下降，牧草地保持不变，其余地类所占比重有所上升。 与2000年相比，2004年林草地的优势格局进一步得到强化（合占比重达到70.23%）。耕地面积占幅员面积的比重下降0.83个百分点，略有下降的有未利用土地、水域和牧草地。值得关注的是在“退耕还林还草”的大背景下，牧草地占幅员面积的比重下降0.04个百分点。 到2006年，仍为林草地为主导优势的格局，二者合占上升0.15%。在城市化快速推进的背景下，居民点及工矿用地中的城市用地和建制镇用地占比重超过15%，农村居民点占比重降至76%。交通用地中农村道路占比重降至57.8%,公路用地占比重升至37.5%。五个地貌区的土地利用/覆盖格局与全省的变化基本一致。值得关注的是盆西平原区的交通用地上升幅度和盆地丘陵区的未利用土地的开发利用力度明显大于其它地貌区。 （2）1996-2006年10年间土地利用/覆盖格局的变化 1996-2000年4年间，耕地、水域和未利用地三个地类下降，年均减少0.75、0.19和0.32个百分点。其中耕地年均减少49229.0公顷，约一半流向林地，13.77%流向园地，约20%流向建设用地。另外5个地类面积增长，增长绝对量最大的是林地，年均增长40063.7公顷，交通用地增幅最大，4年年均增长达1.95%。 2001-2004年是西部大开发逐步推进、“退耕还林还草”项目全面展开和土地整理深入实施的关键期，LUCC更为深刻。耕地、未利用地、水域和牧草地四个地类面积下降，其余地类按增长幅度依次是园地、交通用地、居民点及工矿用地和林地。耕地加速下降，年均降幅达到1.59%，其减少去向主要是林地（占66.75%）和园地（占19.84%），其增加来源主要是未利用地、园地和水域。交通用地的增幅最大，为3.96%,其增加主要来源于耕地、未利用土地和林地，分别占49.96%、16.63%和13.09%。居民点及工矿用地增长幅度为3.12%。 从1996年到2006年的10年间，耕地、未利用地、水域和牧草地下降幅度分别为10.36%、3.61%、1.34%和0.26%。园地增幅达23.61%。绝对面积增长最大的则是林地，达630733.3公顷。交通用地和居民点及工矿用地增幅也较大，分别为15.00%和9.31%。 10年间年均总变化量为310326.6公顷，2000年-2004年之间变化最大（为356865.8公顷），高于平均变化量，而1996-2000年间和2004-2006年间都小于平均变化量。 （3）10年间不同地貌区的LUCC变化 盆西平原区的特点是园地大幅上升达77%，居民点及工矿用地和交通用地也大幅上升，耕地、未利用地下降幅度大，该区耕地、水域、未利用地的减少强度和园地、居民点及工矿用地、交通用地的上升强度均居五区第一；盆地丘陵区的特点是牧草地下降幅度大，为-36.89%,交通用地、园地和林地上升幅度较大，该区耕地减少、未利用地减少、林地增加、居民点及工矿用地和交通用地增加的变化强度均居五区相应地类增减的第二位；盆周山地区的特点是耕地减少较多，交通用地和园地增长较大，该区林地变化强度居各区第一位，牧草地和水域变化强度居各区第二位，耕地、居民点及工矿用地和未利用地居各区第三位；川西南山地区的特点是园地、耕地、交通用地和居民点及工矿用地变化幅度大，另外四个地类变化较小。该区减少的牧草地占全省牧草地减少的97.91%，变化强度居各个地貌区的第一位，园地相对变化强度居五区的第二位；川西北高山高原区的特点是耕地大幅下降、园地大幅上升，交通用地升幅也较大，其余地类变化不大。值得注意的是，该区牧草地和水域面积增加，与全省该地类的变化相反。其余地类的相对变化强度均是五个地貌区中最小的。 用变化强度分值考量变化强度，盆西平原区的变化强度最大，盆地丘陵区和盆周山地区的变化强度相当，川西北高山高原区的变化强度则要小得多。 （4）1996年及2006年全省土地利用/覆盖格局的景观生态学分析 全省是以自然景观占优势（占约70%）、农业景观为补充、建设用地景观居于从属地位的土地利用景观格局。景观多样性和均匀度不高。到2006年，全省总的景观格局并无大的改变。总体情况是随着时间的推移和人类活动的加强，区内景观优势度上升、多样性和均匀度变小。但斑块数减少，斑块面积和斑块孔隙度有所增大。斑块的形状指数和分维数均有所下降，表明受人为干扰有加剧的趋势。反映景观格局结构的破碎度指数有轻微下降。景观指数的变化表明全省土地利用有缓慢集中、规模聚集的趋势。 （5）三大生态建设工程对土地利用/覆盖变化的影响 1996-2006年间LUCC与三大生态建设工程实施的耦合分析，发现退耕工程对耕地、林地、牧草地等地类覆盖变化的影响最大，天保工程次之，长防工程最小。 2.四川省LUCC驱动力分析 （1）总体分析： 从整体上分析，人为因素对区域整体LUCC的影响从1996年的63.32%增加到2006年的66.99%，变得日益强烈。同时人为因素影响强度表现出明显的区域差异，地势平缓、经济区位条件好的区域其人为影响强度明显较高。 政策体制转变下的经济高速增长、快速的城市化、工业化过程和生态建设是四川省LUCC宏观尺度的驱动因素。区域的LUCC主要受到了由内向外(从城市到乡村)和由外向内(从山顶向平地)两种作用力的共同推动。局部尺度上，如距离交通线、水利线、中心城市的远近，地形凸起、大型独立项目落址、重污染项目的阻隔等，甚至一些乡规民俗等因素也会成为LUCC的驱动影响因素。在较小的尺度上,人类个体行为选择对LUCC的影响也是存在的。 　　根据驱动因子的特性作者将其划分为驱变、阻变、良性、惰性因子等类型。 （2）分地貌区的驱动因子分析 各地貌区都存在城市化、工业化、生态工程实施、自然灾害等驱动因子，但主次不一。对于盆西平原和盆地丘陵区，城市化、工业化是前两位的因子，而对另外三个地貌区，生态工程实施和产业结构调整则成为第第一、二位的驱动因子。 （3）分地类的驱动因子分析（以坡耕地为例） 分坡度的耕地变化分析发现，耕地减少主要集中在2°以下的平地、15°-25°和25°以上三个坡度级，是其它坡度级耕地减幅的三倍左右。这表明耕地减少受城市化进程和“退耕还林还草”工程驱动影响尤为巨大。 3.土地利用格局优化、集约利用评价和可持续利用及对策研究 （1）土地利用格局优化的战略选择及调整预测 土地利用格局调整的战略是农业生产用地、建设用地和生态及其他用地占幅员的比重分别稳定在13%、7%和80%左右，重点是三大类别内部二级和三级地类的合理调整。 （2）全省土地集约利用评价 全省农用地利用集约度为0.46，总体上集约度不高，处于较适度利用阶段。建设用地利用集约度为0.38，处于较适度利用阶段。集约利用提升空间较大。 农用地的潜力主要在于加强土地保育、完善利用制度、提高单产。城市建设用地的包括存量潜力、强度潜力、结构潜力，空间很大。农村居民点整理潜力可以逐步挖掘。 （3）新增建设用地集约利用的统筹安排 据测算，到2020年，四川省城市建设用地需求量在463850-492360hm2之间，城镇各业新增建设用地规模为361276.79hm2，占用耕地200565.94 hm2。2004-2020年间四川省农村居民点整理潜力33.86万hm2。农村居民点建设用地需求量为70.57万公顷。 （4）土地集约利用措施与坡耕地可持续利用战略 提出了土地集约利用的措施。在对坡耕地生态系统结构与功能分析的基础上，提出坡耕地可持续利用战略与生态恢复战略，并从技术和政策层面提出了坡耕地合理利用和生态退耕的措施和建议。 LUCC is one of the key questions of global change and sustainable development of society. After the opening and reform of China, the society and economy of Sichuan Province developed very fast ,the land-use/cover changed very strong droved by many factors .But nowadays we have no constant spatial-temporal study and driving force analysis about the whole province based on investigation. And it is lack of land sustainable utilization study based on correlative study. So we choose all the land resource in Sichuan, combine RS and GIS and field investigation, and take statistic-mathematic means and system analysis, to study the LUCC patterns and different scale driving force of different physiognomy regions, land cover types and periods; to analyze the current situation and potential of land resource intensive utilization, and gave out corresponding measurements. We found that forest and grassland are the dominant cover types of Sichuan provincial land –use/cover pattern, and becoming more and more stronger from 1996 to 2006,the natural landscape is the metric and occupy 70%,the diversity and evenness index are not high; the totally change quantity from 2000 to 2004 is the biggest; cultivated land especially steep cultivated land ,garden plot, forestry land ,settlement and industry land and traffic land changed relative stronger; among five physiognomy regions ,the changing intensity of PEN XI PING YUAN QU is the biggest, CHUAN XI BEI GAO SHAN GAO QU is smallest; under the background of policy system changing, the fast developing of economy, fast urbanization and industrialization and ecology construction are the macro-scale driving force of Sichuan provincial LUCC; to compare the impacts of “TUI GENG GONG CHENG” on LUCC especially to cultivated land ,forestry land and grassland is strongest, “TIAN BAO GONG CHENG ” is stronger,“ HANG FANG GONG CHENG” is smallest; the intensive utilization level of farmland and construction land of whole province is relative moderation, there is huge potential to excavate and fulfill the increasing demand of construction land；we must take synthetic measurements to accelerate the sustainable utilization of land resource, including administrative, economical ,technological and ecological policies.

Effects of Naotan Pill on repair of neural cells and cognitive disorders in juvenile rats following hypoxia and ischemia

BACKGROUND: Hypoxia and ischemia induce neuronal damage, decreased neuronal numbers and synaptophysin levels, and deficits in learning and memory functions. Previous studies have shown that lycium barbarum polysaccharide, the most effective component of barbary wolfberry fruit, has protective effects on neural cells in hypoxia-ischemia. OBJECTIVE: To investigate the effects of Naotan Pill on glutamate-treated neural cells and on cognitive function in juvenile rats following hypoxia-ischemia. DESIGN, TIME AND SETTING: The randomized, controlled, in vivo study was performed at the Cell Laboratory of Lanzhou University, Lanzhou Institute of Modern Physics of Chinese Academy of Sciences, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from December 2005 to August 2006. The cellular neurobiology, in vitro experiment was conducted at the Institute of Human Anatomy, Histology, Embryology and Neuroscience, School of Basic Medical Sciences, Lanzhou University, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from March 2007 to January 2008. MATERIALS: Naotan Pill, composed of barbary wolfberry fruit, danshen root, grassleaf sweetflag rhizome, and glossy privet fruit, was prepared by Gansu Provincial Rehabilitation Center, China. Rabbit anti-synaptophysin, choline acetyl transferase polyclonal antibody, streptavidin-biotin complex kit and diaminobenzidine kit (Boster, Wuhan, China), as well as glutamate (Hualian, Shanghai, China) were used in this study. METHODS: Cortical neural cells were isolated from neonatal Wistar rats. Neural cell damage models were induced using glutamate, and administered Naotan Pill prior to and following damage. A total of 54 juvenile Wistar rats were equally and randomly assigned into model, Naotan Pill, and sham operation groups. The left common carotid artery was ligated, and then rat models of hypoxic-ischemic injury were assigned to the model and Naotan Pill groups. At 2 days following model induction, rats in the Naotan Pill group were administered Naotan Pill suspension for 21 days. In the model and sham operation groups, rats received an equal volume of saline. MAIN OUTCOME MEASURES: Neural cell morphology was observed using an inverted phase contrast microscope. Survival rate of neural cells was measured by MTT assay. Synaptophysin and choline acetyl transferase expression was observed in the hippocampal CA1 region of juvenile rats using immunohistochemistry. Cognitive function was tested by the Morris water maze. RESULTS: Pathological changes were detected in glutamate-treated neural cells. Neural cell morphology remained normal after Naotan Pill intervention. Absorbance and survival rate of neural cells were significantly greater following Naotan Pill intervention, compared to glutamate-treated neural cells (P < 0.05). Synaptophysin and choline acetyl transferase expression was lowest in the hippocampal CA1 region in the model group and highest in the sham operation group. Significant differences among groups were observed (P < 0.05). Escape latency and swimming distance were significantly longer in the model group compared to the Naotan Pill group (P < 0.05). CONCLUSION: Naotan Pill exhibited protective and repair effects on glutamate-treated neural cells. Naotan Pill upregulated synaptophysin and choline acetyl transferase expression in the hippocampus and improved cognitive function in rats following hypoxia-ischemia.

On the meaning of integration in coastal zone management

This paper discusses the definition and use of the term ‘integrated management’ in the context of coastal and ocean resources. It identifies several components which appear to be needed to establish an integrated management system for a large area subject to multiple use and jurisdiction. It suggests that the basis of integrated management should be a clear articulation of common purpose which addresses long term needs and vision. Once developed, this common purpose should be securely established to provide the setting against which sectoral and agencies managers and the community conduct and co-ordinate their activities.

云南碧塔海自然保护区生态旅游开发模式研究

Bita lake provincial natural reserve is located in Shangri La region of North western Yunnan,and was set as a demonstrating area for ecotourism exploitation in 1998.After a year's exploitation construction and half a year's operation as a branch of the 99' Kunming International Horticulture Exposition to accept tourists,it was proved that the ecotourism demonstrating area attained four integrated functions of ecotourism,i.e,tourism,protection,poverty clearing and environment education.Five exploitation and management models including function zoned exploitation model, featured tourism communication model signs system designing model,local Tibetan family reception model and environmental monitoring model,were also successful,which were demonstrated and spreaded to the whole province.Bita lake provincial natural reserve could be a good sample for the ecotourism exploitation natural reserves of the whole country.

溶蚀岩体渗透水力学特性研究

Seepage control in karstic rock masses is one of the most important problems in domestic hydroelectric engineering and mining engineering as well as traffic engineering. At present permeability assessment and leakage analysis of multi-layer karstic rock masses are mainly qualitative, while seldom quantitative. Quantitative analyses of the permeability coefficient and seepage amount are conducted in this report, which will provide a theoretical basis for the study of seepage law and seepage control treatment of karstic rocks. Based on the field measurements in the horizontal grouting galleries of seepage control curtains on the left bank of the Shuibuya Hydropower Project on the Qingjiang river, a hydraulic model is established in this report, and the computation results will provide a scientific basis for optimization of grouting curtain engineering. Following issues are addressed in the report. (1) Based on the in-situ measurements of fissures and karstic cavities in grouting galleries, the characteristics of karstic rock mass is analyzed, and a stochastic structural model of karstic rock masses is set up, which will provide the basis for calculation of the permeability and leakage amount of karstic rock mass. (2) According to the distribution of the measured joints in the grouting galleries and the stochastic results obtained from the stochastic structural model of karstic rock mass between grouting galleries, a formula for computation of permeability tensor of fracturing system is set up, and a computation program is made with Visual Basic language. The computation results will be helpful for zoning of fissured rock masses and calculation of seepage amount as well as optimization of seepage control curtains. (3) Fractal theory is used to describe quantitatively the roughness of conduit walls of karstic systems and the sinuosity of karstic conduits. It is proposed that the roughness coefficient of kastic caves can be expressed by both fractal dimension Ds and Dr that represent respectively the extension sinuosity of karstic caves and the roughness of the conduit walls. The existing formula for calculating the seepage amount of karstic conduits is revised and programmed. The seepage amount of rock masses in the measured grouting galleries is estimated under the condition that no seepage control measures are taken before reservoir impoundment, and the results will be helpful for design and construction optimization of seepage curtains of the Shuibuya hydropower project. This report is one part of the subject "Karstic hydrogeology and the structural model and seepage hydraulics of karstic rock masses", a sub-program of "Study on seepage hydraulics of multi-layer karstic rock masses and its application in seepage control curtain engineering", which is financially supported by the Hubei Provincial key science and technology programme.

中国粮食生产的区域演进研究

Grain is one of the primary material conditions of the human survival and the grain production concerns the stability and development of the society directly. The regional patterns influence greatly on the grain production and the rational production distribution the regional comparative advantages and promotes grain production. This thesis starts with summarizing of the characteristics of changes and the overall trend of regional pattern of grain production of our country since 1949. Then it carries on network analyses to the factors, which influences the evolvement of regional grain production patterns of our country. And finally it gives some proposals to the grain production distribution in the future. The main content includes: Firstly, Reviewing the regional evolvement of grain production in our country, and analyzing the changes of the regional pattern of grain production of our country on the provincial scale and county scale separately, since 1949, especially since the reform and opening up policy. The main grain production areas are acting an important position in ensuring the national grain security, so this thesis analyses the main matter of the main grain production areas, forecasts the grain production situation in the future, and selects the Northeastern main grain production areas as the typical area to carry on the positive research. Secondly, this thesis analyzes the origin causes from two respects of natural and social economy of the regional evolvement pattern of grain production in China. Thirdly, based on the summarizing to the status of the regional pattern of the grain production, this thesis proposes the precept of the grain production distribution in the future in our country. Therefore, the areas of three major cereal crops, rice, wheat and corn, are confirmed on the basis of the comparative advantages. Finally, this thesis puts forward the security system of guaranteeing the grain production progressing steady in China. According to the above analysis, some conclusions have been achieved as follows: (1) The grain gross production gets on extricating itself from awkward position frequently while fluctuating greatly annually since 1949 in China. (2) Since the reform, its traditional regional pattern of grain production, the most of which was concentrated in the south area, has changed rapidly. China's center of gravity of grain production has shifted from the south to the north, and on the belts of latitude, the grain production has represented a trend of focusing to the middle area in China. (3) The main grain production areas play a very important role in ensuring China's food security. With their relative severe situation of the problems of agriculture, rural area and peasant, China has carried out a series of measures, which aim at improving the food-producing conditions of the main grain production areas, and enhancing the grain yields there. Under this condition, a forecast of the producing amount of the main grain production areas under the nation's self-supplying rate of over 95% shows that the increasing provision production in these areas can meet the demand of the country. (4) The natural and social economic factors influence together on the changes of the grain production regional pattern. Along with the state system transition and progress of agricultural science and technology, the regional pattern of grain production is affected heavier by the agricultural policy and technological elements. (5) The grain production will be concentrated to the middle province in the future, which economic development level being medium-sized; According to crop allocation, although the rice superiority production area located in the South, its comparative advantage index is little in some degree. Meanwhile, the wheat and corn superiority production areas are in the North mainly and its scale superiority and production level advantage are all comparatively obviously.

Cross-Border Unitization and Joint Development Agreements: An International Law Perspective

Okoye, Adaeze, et al, 'Cross-Border Unitization and Joint Development Agreements: An International Law Perspective', Houston Journal of International Law (2007) 29(2) pp.355-425 RAE2008

Women, Authorship and Literary Culture, 1690 - 1740

Prescott, S. (2003). Women, Authorship and Literary Culture, 1690 - 1740. Basingstoke: Palgrave Macmillan. RAE2008