巢湖农业面源污染控制的生态补偿措施和政策思考

巢湖流域是安徽省重要的经济区,但如今巢湖已成为污染最为严重的淡水湖之一,治理巢湖刻不容缓.通过对巢湖流域种植业、畜禽养殖业、水产养殖业的污染源调查,分析当前造成巢湖农业面源污染的主要原因,并且结合外部性理论阐述农业面源污染属于外部不经济性,从而提出采用生态补偿的治理措施来达到保护巢湖水资源目的的经济手段,其中包括依托项目补偿、推动产业结构调整、发展生态农业、推进农村生态建设等方面,同时也探讨了巢湖农业面源污染控制的生态补偿政策.     

The Suaeda liaotungensis kitag betaine aldehyde dehydrogenase gene improves salt tolerance of transgenic maize mediated with minimum linear length of DNA fragment

In this research we established a particular vector-free and marker-free plant transformation system of maize to overcome the obstacles of biosafety limits. The BADH gene was introduced into maize by pollen-tube pathway, using the principle of minimum linear length of the transformation element, which was composed of only the BADH gene, expression regulatory sequence (35S CAMV promoter, NOS terminator), and T-DNA border sequence at both sides. Twenty-seven of 2076 transformed samples were positive in PCR amplification and the PCR positive rate of T₁ generation was 1.3%. Further Southern blotting results indicated that the BADH gene was integrated into maize genome. Transgenic lines of progeny were examined for tolerance to NaCl by induced salt stress with 250 mM NaCl Hoagland solution. After 15 days of treatment, 73.9–100% of the transgenic seedlings survived and grew well, whereas most wild-type seedlings wilted and showed loss of chlorophyll. Only 8.9% of the wild-type plants survived but gradually died after salt stress. The electrical conductivity of the transgenic line of progeny after salt stress was lower than wild type. The transgenic progeny had higher glycinebetaine and Chlorophyll content than wild type after salt stress.     

关于生物质气化集中供气规范化问题的探讨

近年来,我国生物质气化技术发展迅速,但在技术推广中出现了很多问题,其主要原因是没有规范化生产和管理。本文探讨了生物质气化集中供气规范化的有关问题。     

顽拗植物龙眼果皮中总RNA的提取方法研究

【研究目的】为建立适于富含多糖和多酚等物质的龙眼果皮总RNA提取的方法;【方法】采用TRIzoL法、Tris-硼酸法和改良CTAB法提取龙眼果皮的总RNA。并通过凝胶电泳、紫外分光光度法检测提取的RNA样品的品质;【结果】改良CTAB法、Tris-硼酸法所提取的RNA经电泳检测。28SrRNA和18SrRNA条带清晰。RT-PCR得到的条带与目的片断大小一致。说明所提取的RNA纯度高、质量好;TRJZOL法所得到的RNA降解严重,没有得到完整的电泳条带;【结论】改良CTAB法和Tris-硼酸法适于富含多糖和多酚等物质的龙眼果皮总RNA的提取。     

水肥交互作用对黄土高原南瓜光合特性及其产量的影响

通过不同的灌水和施肥处理,研究水肥交互作用对南瓜光合特性日变化及产量的影响,结果表明：水分与施肥因子对南瓜叶片的光合特性和产量有重要影响,在水分胁迫的情况下,肥水交互作用不显著,在水分较低的情况下,二者表现互为限制条件的协同作用;在水分较高的情况下,肥水交互作用转变成顺序加和作用。其中单因素效应大小表现为：氮〉水〉磷,耦合效应大小表现为：氮与水耦合〉氮与磷耦合〉磷与水耦合。在水分适宜时,适宜的施肥量（施氮量50kg/hm^2、施磷量35 kg/hm^2）可以提高南瓜光合速率和产量,不施肥或施肥量过高都会影响南瓜光合速率和产量。     

我国夏季降水类型初探（英文）

[Objective] Study on the spatial distribution of summer precipitation patterns and interannual and interdecadal variability.[Method] The summer precipitation patterns were obtained from standard field of summer precipitation data for 160 observation stations in China during 1951-2000 by the utilization of empirical orthogonal function(EOF),and characteristics of interannual and interdecadal variability were analyzed.[Result] The summer precipitation mainly distributes in eastern part of China;The 1st,2nd and 3rd EOF modes of spatial distribution are especially remarkable as well consistent with the results of previous reports about three rainfall patterns from analysis on the percentages of precipitation anomaly of summer.[Conclusion] There exists interannual and interdecadal variability for summer precipitation in China.     

谈校园网建设应掌控的关键问题

主要论述了校园网设计与建设过程中,应确立建设校园网的目标,技术方案设计,信息资源建设,管理与安全五个关键问题。     

浅析无线路由器信号覆盖范围的拓展

由干无线网络设备的有效信号覆盖范围限制,在实际应用中经常出现无信号或信号不稳定现象,本文根据无线局域网中核心设备无线路由器的特点,总结了信号覆盖范围拓展的常用方法.并重点讨论了采用WDS技术连接多个路由器来拓展信号覆盖范围的方法,并给出了具体的配置步骤.     

基于差分GPS技术的淤地坝泥沙淤积量估算

淤地坝是黄土高原水土流失治理中的一项重要措施。但是早期建设的淤地坝缺乏监测资料,对现已淤满坝地拦截泥沙量的估算成为当前研究中的一个难点问题。该文选取延安宝塔区羊圈沟小流域1979年修建的淤地坝为研究对象,采用高精度差分GPS技术,测量坝地淤积面平均高程和淤地面积,结合1977年1︰10 000地形图,建立高程—面积/淤积量曲线,得出羊圈沟淤地坝淤积泥沙方量为155 849.2 m3,并通过计算得到建坝至淤满期内（1979－2004年）年平均土壤侵蚀模数4 052.1 t·km-2·a-1,属于中度侵蚀。差分GPS技术的应用为准确估算淤地坝泥沙淤积量提供了技术支撑,可以弥补历史上侵蚀产沙数据,而且对定量评价水土流失及其治理效益提供了依据。     

Aquatic Acidification Sensitivity for Regional Environment: a Multi-Indicator Evaluation Approach

With the aggravation of acid rain pollution and the enlarging of the acid rain regions in China, the sensitivity evaluation of natural waters to acidification on a regional scale become increasingly important. Acidification models based on a single indicator cannot give much information on aquatic acidification because of their simplicity; yet acidification models based on physical, chemical, hydrological and/or biological processes are not suitable for large scale regional research because of their exceptional complexity. In this paper, a multi-indicator comprehensive model for aquatic acidification sensitivity is proposed and applied. This model comprises some of the most important factors that are considered to influence water acidification, in particular: acid neutralization capacity, acidification capacity, acidification sensitive index, cation exchange capacity of soil, pH of soil, and weathering shuck types of soil-forming. It highlights the key stages of aquatic acidification by acid neutralization capacity, acidification capacity, and acidification sensitivity index. The model thereby estimates the acidification sensitivity of natural waters by using these indicators according to a weighting system. Equal-weight and non-equal-weight approaches are separately used to combine the six indicators into an overall sensitivity index of aquatic acidification. The result derived from an application to China on a national scale indicates the practicability of this approach. In China, the sensitive natural waters emerge in Southern China, which is already a heavy acid rain region, and in Northeastern China where the rainwater is beginning to become much acidic.