金融危机后全球对虾贸易格局与出口竞争力研究

受国际金融危机的影响,全球经济增长放缓,对虾市场也受到了一定的冲击。金融危机后,对虾贸易开始复苏,并仍然集中在亚洲、美洲和欧洲三大区域。其中,泰国、越南、中国、印度尼西亚、印度的对虾产品国际市场占有率较高,并对美欧日三大进口市场具有较高的渗透率;厄瓜多尔、越南、泰国、孟加拉的对虾出口竞争力很强;上述国家对虾产品的比较优势显著。通过对湛江国联水产出口经验的借鉴,为增强中国对虾出口竞争力提供了启示。     

生态政治学:理论背景 现实意义及发展前景

生态学的最新发展为生态政治学提供了理论养分。现代社会所面临的生态问题归根结蒂是人与自身生存的世界之间的关系危机。生态政治学在当代社会中既有其存在的合理性和批判意义,也有其局限性。     

泥石流滩地土地生产潜力评价——以云南小江流域蒋家沟为例

小江流域泥石流滩地水源充足、热量丰富,气候生产潜力(47641kghm-2)较高。本文应用加权指数和法确定了不同类型泥石流滩地(荒滩地、改良滩地和非改良滩地)土壤有效系数f(s)分别为0.405、0.684和0.594;根据生产力阶乘公式计算其气候—土壤生产潜力分别为19295kghm-2、32586kghm-2和28299kghm-2。通过实地调查验证,本文对泥石流滩地生产潜力的估算与现实生产力水平基本吻合,证明本文提出的泥石流滩地土壤有效系数切实可行。     

高校图书馆人才危机及其对策

随着信息技术的发展和人们信息需求水平的提高,高校图书馆的人才危机也发生了变化,主要体现为高校图书馆馆员有限的能力与读者日益提高的信息需求水平的矛盾。这是由于高校图书馆馆员偏低的学历层次、不合理的学科结构以及较低的工作积极性所造成的。对此,提出了诸如建立有效的交流机制、激励机制、人员流动机制以及提升馆员学历层次等办法及建议,来缓和这一矛盾。     

Constraints and possibilities for developing aquaculture

World aquaculture production in 1990 reached some 15 million tonnes, and predictions indicate that future production will reach 19.6 million tonnes by 2000, 37.5 million tonnes by 2010, and 62.4 million tonnes by 2025. Meanwhile, world fisheries production from capture will remain stable at about 100 million tonnes. Thus, all future increase in seafood supplies will have to come from aquaculture.Possibilities for development of aquaculture exist in a number of areas around the world. Technology and natural conditions determine the choice of sites and species to be produced, but current research indicates that a number of new species will be added to the present aquaculture production in the coming years. However, well-known species such as carp, tilapia, trout, salmon, turbot, halibut, cod, and sturgeon will be the most important in the immediate future. Among the crustaceans, shrimp will continue to be an important item, as will various kinds of gastropods and bivalves.Regions with a particular suitability for development of aquaculture include Africa, Asia, and Latin America. Freshwater aquaculture may also be developed on a larger scale in the former Eastern European countries, including the former Soviet Union, but here (and in Africa), political and economic constraints will slow down development for the next decade. A major constraint for development of aquaculture in Africa is the lack of infrastructure, as well as political problems, slow or deficient bureaucracies, and to some extent pollution. In Eastern Europe, development will be hindered by the lack of capital, and uncertainty about the political and economic development. Eastern Europe also has a major environmental problem, which may limit growth within this field. In Asia, space and availability of suitable sites are becoming a problem, as are pollution, diseases, and in some cases overproduction.A general constraint to global development of aquaculture may be price fluctuations, which affect the investment willingness of interested investors. This question must be seen in connection with the economics of operation. As new species are being launched, there is usually a short period of high profits, followed by a period of price reductions, and the collapse of several operators. After such turbulence, serious operators with proper management survive, and go on to operate a reasonably profitable business. The mechanism seems to be true for all new business areas, and does create a problem for sustained investor interest in aquaculture development.     

大力加湖鲟鱼放养场浮游植物及鱼产潜力

2004年5、7、9、12月对大力加湖浮游植物的种类组成结构特征进行了研究。结果表明：大力加湖鲟鱼放养场浮游植物96个种属,密度255.54×10~4 ind．/L,生物量14.166 mg/L。浮游植物季节变化比较明显,密度秋季最高为456.160×10~4 ind．/L,生物量以秋季最高30.105 mg/L。多样性指数变化是夏季＞秋季＞冬季＞春季;均匀度指数变化是冬季＞夏季＞秋季＞春季。全库总鱼产潜力527760 kg,总放养量2804800尾。     

欧债危机对中欧农产品贸易的影响分析

本文分析了欧债危机对中欧农产品贸易的可能影响途径和机制,并利用双边农产品贸易数据对欧债危机的影响进行了初步判断。结果表明,虽然年度长期趋势所反映的欧债危机影响不明显,但是月度短期趋势反映欧债危机已经致使中欧农产品贸易出现明显的增长放缓趋势,且影响在危机核心国和非核心国之间的差异不明显,具有整体性的特征。因此,不能因为年度农产品贸易额还在快速增长而盲目乐观,而必须加强监测和采取积极的应对措施。     

重庆市地区可持续发展的水资源问题探讨

分析了重庆市地区目前人均水量少,而且在时空分布上东南多、西北少,水体污染、水旱灾害频繁,水资源开发利用率低,水土流失严重等水资源短缺、水环境恶化等严峻形势和危机状况,以及对重庆市地区环境生态、经济社会发展等各方面的影响.提出了进～步加大长江流域水环境的保护力度,治理污染、实现污水资源化,加强深化供水管理体制改革等解决本地区水资源危机,使之可持续发展的策略.     

设施蔬菜肥料施用现状调查分析及减施潜力估算

对赤峰市典型设施农业区20个种植户进行施肥情况调查。结果表明：赤峰市设施农业有机肥投入量偏高,化肥以基施为主。赤峰市设施蔬菜调查区氮、磷、钾养分总投入量平均分别达 2575、1266、2790 kg/hm _² ,土壤养分投入过大养分过量现象严重。每季黄瓜、番茄、辣椒 N∶P ₂ O ₅ ∶K ₂ O 平均为1:0.49:1.09,养分比例适中。施入土壤的养分总量远超过各自推荐施肥量,养分减施潜力较大。赤峰市设施蔬菜应大力推广测土配方施肥技术,实现资源节约型、环境友好型现代化高效农业。     

秦岭中段北坡主要植被类型潜在火行为划分

利用秦岭中段北坡２０块样地１００块样方的实际调查资料,采用村冠最大密度Ｄ。地表可燃物载量Ｗ及地且可燃物持水量Ｍ作为数量化分类依据,运用相异分析法对２０块样地作了聚类分析,结果表明,秦岭中段北坡的森林潜在火行为可划分为１２个类型,而实际调查植被的潜在火行为仅可为５个类型。