坡地农林复合系统的结构类型与效益分析─以长江三峡库区坡地农业为例

本义认为现代术语的农林复合系统来源于生产实践,体现了农业与林业的有机结合、品种生态和经济的有机结合、产品多样化以及管理科学化4个方面相统一的特点。文章在分析三峡库区农林复合系统的类型结构基础上,提出了农林复合系统可以进行层次结构划分的观点。最后,以典型案例研究方法入手,对1种农林结构类型进行效益分析,结果表明,采用植物篱农林复合坡地系统,是现阶段生产力水平下实现坡地生态经济协调发展的有效途径,值得广泛推广。     

菏泽市村庄改造试点工作调查与思考

菏泽市自2006年启动以村庄改造为主要内容的＂城市建设用地增加与农村建设用地减少＂挂钩试点工作,注重三个基础,搞好三个结合,坚持三个原则,抓住三个关键,取得了农村得实惠、企业得市场、发展得空间、政府得人心的良好效果。但由于部分县、乡干部认识尚不到位、政策宣传不到位、项目资金争取不到位等原因,使这项工作还存在许多问题,通过认真分析研究,提出了符合菏泽实际的强化宣传、规划先行、政策引导、多方融资、慎选试点等切实可行的对策和建议。     

LAND DEGRADATION AND ITS MANAGEMENT IN THE ARID AND SEMI ARID AREAS OF CHINA

Ｉ.ＬａｎｄＤｅｇｒａｄａｔｉｏｎＤｉｓｔｒｉｂｕｔｉｏｎａｎｄＩｔｓＣｈａｒａｃｔｅｒｉｓｔｉｃｓＴｈｅｆａｒｍｉｎｇｐａｓｔｏｒａｌｔｒａｎｓｉｔｉｏｎａｌｒｅｇｉｏｎｉｎｓｅｍｉａｒｉｄｌａｎｄｏｆｎｏｒｔｈｅｒｎＣｈｉｎａｉｓｔｈｅｍｏｓｔｔｙｐｉｃａｌｒｅｇｉｏｎｏｆｌａｎｄｄｅｇｒａｄａｔｉｏｎ,ａｎｄａｌｓｏｔｈｅｒｅｇｉｏｎｗｉｔｈｅｘｔｅｎｓｉｖｅｌｙｄｅｖｅｌｏｐｉｎｇｓａｎｄｙｄｅｓｅｒｔｉｆｉｃａｔｉｏｎ.ＴｈｅｅｘｔｅｎｔｉｓｆｒｏｍＨｏｒｑｉｎＳａｎｄｙＬａｎｄｉｎｔｈ…     

The effects of organic removal treatment on the integrity of δ<Superscript>18</Superscript>O measurements from biogenic silica

Prior to oxygen isotope analysis of biogenic silica by fluorination techniques, sediments must be cleaned of all organic compounds. Despite the expanding volume of research utilising oxygen isotope ratios in biogenic silica in palaeoclimatology, very little is known about the effects of different standard preparation methods for the removal of organic matter on the isotope values. Here we compare a number of methods for the removal of organic matter in order to assess their effectiveness and influence on subsequent isotope measurements. Not all the methods described here effectively removed organic matter, the best treatments were H₂O₂ and ignition in air at 550°C. Ignition in air at 950°C, and heating in vacuum at 250 and 450°C results in marked alteration of isotope values, whereas use of hydrogen peroxide (H₂O₂), nitric acid (HNO₃) and plasma ashing have little or no effect, within the bounds of analytical error. Ignition in air at 550°C was the most effective technique, and induced no alteration of δ¹⁸O_silica, but practical constraints may limit the application of this method routinely. Our findings indicate that considerable caution is required when preparing sediment for isotope analysis of biogenic silica.     

试论气候异常对重大工程建设的影响

依据大量实例阐明了气候与重大工程建设的关系,以及气候异常变化对重大工程的影响,指出了在重大工程建设中因未考虑气候异常变化所带来的严重后果.提出在重大工程规划、设计和建设中应注意的气候灾害问题.     

完善气象事业单位项目资金管理

基于构件的软件开发技术在进入Internet时代后,产生了新的特性,本文通过一个实例分析了在Internet环境下基于构件的软件开发技术在.Net平台中的应用方法.     

Copula-based identification of the non-stationarity of the relation between runoff and sediment load

It is important to identify the non-stationarity in the relation between runoff and sediment load under the backdrop of the changing environment. This relation helps to further understand the mechanisms of runoff and sediment yield. A copula-based method was used to detect possible change points in the relation between runoff and sediment load in the Wei River Basin (WRB), China, where soil erosion is a very severe issue. The modified Mann-Kendall trend test method was applied to obtain the trends of runoff and sediment load spanning 1960–2010 at monthly and annual timescales. Finally, the causes of the identified non-stationarity of the relation between runoff and sediment load were roughly analyzed from the perspective of climate change and human activities. Results indicated that:(1) the runoff and sediment load in the Jinghe and Wei rivers were generally characterized by noticeably decreasing trends at both monthly and annual timescales;(2) both the Jinghe and Wei rivers had a common change point (2002), implying that the stationarity of the relation between runoff and sediment load in the Jinghe and Wei River was invalid; (3) human activities including increasing water consumption and growing application of soil conservation practices are dominant factors resulting in non-stationarity in the rela-tion between runoff and sediment load in the WRB. This study provides a new idea for identifying the non-stationarity of multivariate relation in the hydro-meteorological field under the background of the changing environment.     

1999年我国天气气候特点

１９９９年我国主要天气气候特点可概括为：大部地区冬春连旱,夏季南涝北旱,秋季旱渍并存。全国持续偏暖,但幅度已较１９９８年有所下降,而且阶段性变化也更趋明显,部分地区遭受了高温或低温霜冻危害。热带风暴生成和登陆我国的个偏省;沙尘暴异常偏早;风雹偏省,损失轻;雾日较多。