Different spontaneous plant communities in Sanmen Pb/Zn mine tailing and their effects on mine tailing physico-chemical properties

Different plant communities have established spontaneously on Sanmen Pb/Zn mine tailing. The site was inspected and four different plant communities were identified according to their species composition. To understand the effects of different communities on mine tailing physico-chemical properties, a community survey was carried out in Sanmen Pb/Zn mine tailing, and the physico-chemical properties and heavy metal (Cu, Pb, Cd and Zn) distribution of mine tailings were determined. Results showed that there were four types of communities (I, II, III and IV) in Sanmen Pb/Zn mine tailing. From community I to IV, the number of plant species and community characteristics (aboveground biomass, underground biomass, coverage and height) consistently increased. Moreover, the nutrient pool and physico-chemical properties of mine tailing consistently reestablished from community I to IV, while the total heavy metal content consistently decreased. The contents of residual fractions, Fe–Mn oxide fractions for Pb, Zn, Cu and Cd and exchangeable fractions for Pb and Zn also consistently decreased. However, the contents of organically bound fraction had no obvious change from community I to IV. Moreover, the contents of Cu organically bound fraction reversely increased. Results demonstrate that communities I, II, III and IV should be a progressive community succession. Moreover, along with the progressive community succession, phytostabilization and phytoextraction of mine tailings are more and more effective.     

凡纳滨对虾α-淀粉酶基因PCR-RFLP多态性与生长性状的相关分析

采用PCR-RFLP法对379尾凡纳滨对虾α-淀粉酶基因(AMY)多态性进行检测,并分析AMY基因多态性与生长性状的相关性.结果表明:引物AMY-5与AMY-6扩增片段均具多态性,引物AMY-5扩增产物有CC,CT和TT 3种基因型,AMY-6扩增产物有AA,AB和BB 3种基因型.AMY基因AMY-5引物位点TT基因...     

Transmitted and reflected coefficients for horizontal or vertical plate type breakwater

Surface or submerged horizontal or vertical plate can be considered as a new concept breakwater.This paper investigates the wave-plate interaction of this type of breakwater by use of the boundary element method.The relationships of wave transmitted and reflected among plate thickness,submergence and length are carefully studied by numerical simulation.It is shown that:(1) The transmitted coefficients of submerged horizontal plate or vertical plate will become larger with the increase of plate thickness and reduce rapidly with the decrease of plate submergence.(2) Both surface horizontal and vertical plate are efficient for intermediate and short wave elimination,but vertical plate is more effective.(3) Submerged horizontal plate can act more effectively than submerged vertical plate does.With all wave frequencies,the vertical plate almost has no wave elimination effect.     

蒸馏海水淡化产品水对铸铁材质腐蚀研究

分析了多级闪蒸海水淡化产品水水质特点,研究了淡化水对铸铁管网的腐蚀影响.利用稳定指数法、失重法、电化学分析和腐蚀产物的XRD检测等方法开展了实验研究.实验结果显示了淡化水对铸铁试片的腐蚀程度及淡化水对铸铁腐蚀产物的类型,可为淡化水进入市政管网提供参考.     

基于Google Map的地震综合信息服务系统构建研究

基于Google地图API接口,采用Oracle数据库管理和AJAX,JavaScript技术,进行地震综合信息服务系统的平台搭建.结果表明该系统具有快速、全面、易操作的特点,解决了目前开发GIS平台数据昂贵、系统维护困难等问题,为用户了解震情提供了良好的平台.     

基于分形理论的江苏省城市规模分布与异速生长特征

以江苏省1996～2008年城市非农业人口和建成区土地面积为主要数据,借助分形地理学中的城市位序一规模分布法则和异速生长定律及其广义分形性质,对全省城市规模分布演化规律、结构容量和城市人口-面积异速生长标度指数、退化关系进行探讨。结果表明：全省城市体系发育较为健全,规模序列结构正处于集中向分散过渡的时期,大中城市成为城...     

中亚热带红壤丘陵区松林生态系统表层土壤活性有机碳空间分异规律

土壤活性有机碳在指示土壤碳库平衡、表征土壤肥力与质量、衡量土壤微生物生长等方面具有重要意义。本文对中亚热带红壤丘陵区松林生态系统93个表层（0～20cm）土壤样品的活性有机碳空间分布特征及其与地形、植被和土壤特性的关系进行了深入分析。结果表明：表层土壤活性有机碳的平均值为1.92g/kg,占土壤有机碳的29.18%,变...     

中国建设占用耕地对经济增长的贡献研究(英文)

The paper applies Cobb-Douglas Production Function and Solow-Swan Model to constructing the calculation model of the contribution rate of cultivated land occupation by construction (CLOC) to China’s economic growth,and analyzes the contribution change of CLOC to China’s economic growth qualitatively and quantitatively.The main conclusions are as follows:1) From 1989 to 2007,the contribution rates of capital,labor,and CLOC to China’s economic growth were 45.76%,8.47%,and 6.19% respectively.2) From the period 1989-1996 to the period 1997-2007 the contribution rate of CLOC to China’s economic growth increased from 5.40% to 5.87%.The degree of contribution was enhanced significantly.3) The contribution of CLOC to China’s economic growth had a spatial distribution characteristic that the contribution rate of eastern coastal regions was the highest,that of central regions came second,and that of western regions the lowest.The paper indicates that in order to enhance the contribution of CLOC to China’s economic growth,some relevant economic and administrative measures might be taken,and land might be used intensively and economically to increase land economic density.The cost of promoting gross domestic product (GDP) growth might be reduced as much as possible to achieve higher GDP growth and lower land resource consumption.     

Evaluation on the two filling functions for the recovery of forest information in mountainous shadows on Landsat ETM + Image

In general,topographic shadow may reduce performance of forest mapping over mountainous regions in remotely sensed images.In this paper,information in shadow was synthesized by using two filling techniques,namely,roifill and imfill,in order to improve the accuracy of forest mapping over mountainous regions.These two methods were applied to Landsat Enhanced Thematic Mapper (ETM +) multispectral image from Dong Yang County,Zhejiang Province,China.The performance of these methods was compared with two conventi...     

用矩阵摄动法修改结构动力参数

作者应用模型简化技术中的矩阵摄动法来修改结构动力参数，从而避免了修改后结构动力参数的重计算，减少了系统仿真、分析和设计的计算量。算例表明，该方法有较好的计算效率。