作者机构：
[黄玲玲; 周金星; 漆良华; 张旭东] Research Institute of Forestry, CAF, Key Laboratory of Tree Breeding and Cultivation, Beijing 100091, China;[杨模华; 李志辉] School of Resources and Environment, Central South University of Forestry and Technology, Changsha 410004 Hu'nan, China
通讯机构：
[Qi, L.-H.] R;Research Institute of Forestry, CAF, Key Laboratory of Tree Breeding and Cultivation, China
摘要：
Remote sensing provides a useful source of data from which updated land cover information can be extraction for assessing and monitoring environment changes. This paper aims at achieving improved land cover classification performance based image segmentation and support vector machines (SVMs) classification. The object-based classification approach overcame the problem of salt-and-pepper effects found in classification results from traditional pixel-based approaches. The proposed method is a three-stage process, which makes use of the object information from neighboring pixels. Firstly, a robust image segmentation algorithm is used to achieve more homogeneous regions. Secondly, feature information is extracted from each segment and training samples is interactive selected in geographical information system platform. Thirdly, support vector machines classifier is employed to classify the land covers. The experimental results indicate that improved classification accuracy and smoother (more acceptable) is achieved compare with the traditional pixel-based method. Because of the image segmentation process significantly reduces the number of training samples, make SVMs classification method can be applied to information extraction from remotely sensed data.
作者机构：
[ZHU DaoHon] College of Resources and Environment, Central South University of Forestry and Technology, Changsha, China;[ZHU DaoHon] Laboratory of Insect Life Cycles and Physiology, Division of Insect and Animal Sciences, Independent Administrative Institution, Tsukuba;[Seiji Tanaka] Laboratory of Insect Life Cy
通讯机构：
College of Resources and Environment, Central South University of Forestry and Technology, China
摘要：
Two acidic ferrisols, i.e., red soil (RS) and yellow red soil (YRS), from the vicinity regions of non-ferrous ores in Hunan province of China, were leached with simulated acid rain through artificial column experiments. The results show that the total leaching mass of metals are m (Zn)>w (Cu)>m (Cd) from the original soils and w (Cd)>m (Z, n)≫m (Cu) from the contaminated soils with external metals after leaching for 60 d continuously, leaching quantities of Cd and Zn from the contaminated red soil (CRS) are more than that from the contaminated yellow red soil (CYRS), but for Cu, it is almost the same. The preferential fractions for leaching are mainly in exchangeable forms, and content of exchangeable forms decreases significantly in the contaminated soil profiles. The unstable fractions of Cd, Cu and Zn in the RS and YRS increase significantly with the decrease of pH value of simulated acid rain. Changes of fractions of external Cd, Cu, and Zn in the residual CRS and CYRS profiles are significantly affected by the acidity of acid rain, too. After leaching for 60 d continuously, Cd exists mostly in exchangeable form, Cu exists mainly in exchangeable, manganese oxide-occluded and organically bounding forms, and Zn exists in residual in CRS and CYRS profiles. Most of exchangeable Cd and Zn exist only small in surface layer (0-20 cm) and are transferred to the sub-layers, contrarily, Cu accumulates mostly in the topsoil (0-20 cm) with low translocation.
摘要：
Experiments on Zn~(2+) and Cd~(2+) adsorptions on vermiculite in aqueous solutions were conducted to investigate the widely observed adsorbent concentration effect on the traditionally defined adsorption isotherm in the adsorbate range 25-500 mg/L and adsorbent range 10-150 g/L. The results showed that the equilibrium ion adsorption density did not correspond to a unique equilibrium ion concentration in liquid phase. Three adsorbate/adsorbent ratios, the equilibrium adsorption density, the ratio of equilibrium adsorbate concentration in liquid phase to adsorbent concentration, and the ratio of initial adsorbate concentration to adsorbent concentration, were found to be related with unique values in the tested range. Based on the assumption that the equilibrium state of a liquid/solid adsorption system is determined by four mutually related components: adsorbate in liquid phase, adsorbate in solid phase, uncovered adsorption site and covered adsorption site, and that the equilibrium chemical potentials of these components should be equalized, a new model was presented for describing ion adsorption isotherm in liquid/solid systems. The proposed model fit well the experimental data obtained from the examined samples.
作者机构：
[肖永红] College of Life Sciences, Jinggangshan College;[贺一原] College of Resources and Environment, Central South Forestry University;[柳丰; 杨海明] College of Life Sciences, Hunan Normal University
关键词：
食虫沟瘤蛛;白背飞虱;稀土元素;荧光物示踪;除草剂;摄食量
摘要：
采用一种全新的测定方法——荧光物示踪法，以稀土元素铕作为荧光示踪物质，以“水稻-白背飞虱Sogatella furcifera Horvath-食虫沟瘤蛛Ummeliata irtsecticeps Bosenberg et Strand”这一食物链中的水稻和白背飞虱作为铕的传递者，经萃取和反萃取等一系列化学分析方法，定量地测定了3种除草剂胁迫下食虫沟瘤蛛的摄食量。结果表明：施用除草剂西草净、使它隆和高效盖草能以后，食虫沟瘤蛛的存活个体12天内平均每天捕食白背飞虱分别为1．784、2．678和2．856头，均低于对照组的平均个体摄食量3．321头／d；各组12天内个体摄食量的趋势线均为开口向上的抛物线，可用二次方程进行拟合；同时除草剂的喷施亦对食虫沟瘤蛛造成一定的致死率，因而造成施药后食虫沟瘤蛛的种群摄食率减退，第2、5、8天的平均摄食率分别为对照组的52．11％、36．45％和50．27％；药后第12天3个处理组的摄食量均超过了正常值，平均摄食率达到对照组的131．84％。因此在稻田中害虫大发生或天敌群落迁移时应慎用除草剂，以免食虫沟瘤蛛药后摄食量减少导致对目标害虫控制力减弱或由于除草剂的致死力而对食虫沟瘤蛛的群落重建构成威胁。
作者机构：
[Wen, Shi-Zhi; Tang, Chun-Fang; Zhang, Ri-Qing; Li, Ke-Lin] College of Resource and Environment, Central South Forestry University, Changsha 410004, China;[Liu, Yun-Guo] College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
通讯机构：
[Zhang, RQ ] ;Cent S Forestry Univ, Coll Resource & Environm, Changsha 410004, Peoples R China.
摘要：
The engineering application of natural hyperaccumulators in removing or inactivating metal pollutants from soil and surface water in field trials mostly presents the insurmountable shortcoming of low efficiency owing to their little biomass and slow growth. Based on further understanding of the molecular mechanism of metal uptake, translocation, and also the separation, identification, and cloning of some related functional genes, this article highlights and summarizes in detail the advances in research on transgenic techniques, such as Agrobacterium tumefaciens-mediated transformation and particle bombardment, in breeding of plants for metal resistance and accumulation, and points out that deepening the development of transgenic plants is one of the efficient approaches to improving phytoremediation efficiency of metal-contaminated environments. From the viewpoint of sustainable development, governments should strengthen support to the development of genetic engineering for metal resistance and accumulation in plants.
摘要：
Outbreaks of the migratory locust, Locusta migratoria L., occurred in the northwestern part of China. The processes leading to the outbreaks and successful control are described based on locusts collected in infested areas and information obtained from local experts and scientists. Swarms of adults landed on the grazing and farming lands of Jiminay County, Altay Prefecture, the Xingjian Uygur Autonomous Region in 2003 and 2004, and caused substantial damage to agricultural crops and pastures. In the spring of 2004, numerous nymphs that had developed black patterns appeared in Jiminay. They and migrants from the north were sprayed with insecticides during the period from July 20 to August 6, 2004. A total of 4,200 personnel were involved in this mission. As a result, further damage to crops and migration to other areas were prevented. Morphometric measurements indicated that the migrants had reached the body dimensions typical for gregarious forms.
