首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   51篇
  免费   0篇
  国内免费   1篇
废物处理   5篇
环保管理   2篇
综合类   8篇
基础理论   7篇
污染及防治   14篇
评价与监测   4篇
社会与环境   12篇
  2023年   2篇
  2022年   2篇
  2020年   4篇
  2018年   3篇
  2017年   5篇
  2016年   6篇
  2014年   2篇
  2013年   2篇
  2012年   4篇
  2010年   2篇
  2009年   2篇
  2008年   3篇
  2007年   1篇
  2006年   3篇
  2004年   3篇
  2003年   2篇
  2002年   1篇
  1999年   2篇
  1995年   1篇
  1987年   1篇
  1981年   1篇
排序方式: 共有52条查询结果,搜索用时 203 毫秒
31.
32.
Environmental Science and Pollution Research - The present study proposed the relationship among private investment in information and communication technology (ICT), carbon emissions (CO2),...  相似文献   
33.
Radioisotopes carbon 14 and chlorine 36 were used to elucidate the environmental role of trichloroacetic acid (TCA) formerly taken to be a herbicide and a secondary air pollutant with phytotoxic effects. However, use of 14C-labeling posed again known analytical problems, especially in TCA extraction from the sample matrix. Therefore—after evaluation of available methods—a new procedure using decarboxylation of [1,2-14C]TCA combined with extraction of the resultant 14C-chloroform with a non-polar solvent and its subsequent radiometric measurement was developed. The method solves previous difficulties and permits an easy determination of amounts between 0.4 and 20 kBq (10–500 ng g−1) of carrier-less [1,2-14C]TCA in samples from environmental investigations. The procedure is, however, not suitable for direct [36Cl]TCA determination in chlorination studies with 36Cl. Because TCA might be microbially degraded in soil during extraction and sample storage and its extraction from soil or needles is never complete, the decarboxylation method—i.e. 2 h TCA decomposition to chloroform and CO2 in aqueous solution or suspension in closed vial at 90 °C and pH 4.6 with subsequent CHCl3 extraction—is recommended here, estimated V < 7%. Moreover, the influence of pH and temperature on the decarboxylation of TCA in aqueous solution was studied in a broad range and its environmental relevance is shown in the case of TCA decarboxylation in spruce needles which takes place also at ambient temperatures and might amount more than 10–20% after a growing season. A study of TCA distribution in spruce needles after below-ground uptake shows the highest uptake rate into current needles which have, however, a lower TCA content than older needle-year classes, TCA biodegradation in forest soil leads predominatingly to CO2.  相似文献   
34.
Egg rejection belongs to a widely used host tactic to prevent the costs incurred by avian brood parasitism. However, the genetic basis of this behaviour and the effect of host age on the probability of rejecting the parasitic egg remain largely unknown. Here, we used a set of 15 polymorphic microsatellite loci, including a previously detected candidate locus (Ase64), to link genotypes of female great reed warblers (Acrocephalus arundinaceus), a known rejecter, with their egg rejection responses in two host populations. We also tested whether host female age, as a measure of the experience with own eggs, plays a role in rejection of common cuckoo (Cuculus canorus) eggs. We failed to find any consistent association of egg rejection responses with host female genotypes or age. It seems that host decisions on egg rejection show high levels of phenotypic plasticity and are likely to depend on the spatiotemporal variation in the parasitism pressure. Future studies exploring the repeatability of host responses towards parasitic eggs and the role of host individual experience with parasitic eggs would greatly improve our understanding of the variations in host behaviours considering the persistence of brood parasitism in host populations with rejecter phenotypes.  相似文献   
35.
Spiny mice of the genus Acomys (Muridae) represent a very suitable mammalian model for studying factors influencing the secondary sex ratio (SSR). The maternal effort in these rodents is extremely biased in favour of the prenatal period and, therefore, maternal manipulation of the SSR is potentially more advantageous. We studied the SSR in four populations/species of spiny mice kept in family groups consisting of two closely related females, one non-relative male and their descendants. The groups were established from founding animals aged about 3 months (maturing age) and were allowed to breed freely for several months. Each litter was sexed after birth, and relevant data were thoroughly recorded. Altogether, data were collected on 1684 litters: 189 of Acomys sp. from Iran, 203 of A. cilicicus, 875 of A. cahirinus, and 417 of A. dimidiatus. We recorded the sex of 4048 newborns of which 1995 were males and 2053 were females. The overall sex ratio was close to 1:1 (49.2%). Generalized linear mixed models and/or generalized linear models were constructed to evaluate the effect of four life history and eight social variables on the sex ratio. No consistent effects of these variables on the sex ratio were found and, interestingly, none of the variables associated with maternal life history had any effect on the sex ratio. Three factors associated with group composition (i.e. the number of immature males, the number of immature females and the number of breeding females) did have significant effects on the sex ratio, but these effects were not consistent across the studied species. In conclusion, our evaluation of this large dataset revealed that the sex ratio in spiny mice is surprisingly stable.  相似文献   
36.
ABSTRACT

Disaster management spans actions before, during, and after disaster events. Changes in the roles and functions of local governments before a disaster can influence other stages of disaster management. After a chemical spill in 2012, South Korean hazardous chemical management tasks were returned to the central government and local governments’ roles and functions were reduced. To identify associated issues and enhance the hazardous chemical management system, this study analyzed changes in laws and policies and conducted interviews with stakeholders. While the changes helped with centralization, reinforcement, and specification, some loopholes were discovered. The information and human resource capacities of local governments and intra – and intergovernmental relations issues have hindered their active participation before and during chemical disasters. These loopholes can be addressed through institutional enhancements for local governments, such as including them in monitoring hazardous chemical handling facilities, developing codes articulating the division of tasks among departments within them, and providing adequate incentives for them to increase their personnel. This study provides empirical data that informs ongoing debates about the centralization and devolution of disaster management by linking local governments’ ordinary management systems to their disaster management activities.  相似文献   
37.
38.
江苏省夏季浮萍种类及其生长水环境调查   总被引:1,自引:0,他引:1  
对江苏省多个县(市)分布有浮萍的工业区、生活区、农田水体进行调查与采样,观测各地浮萍种类及其生长水体的富营养化状况,探讨水体pH值,铵态氮、硝态氮、总氮、总磷含量与浮萍分布的关系。调查结果表明,浮萍适宜生长在静止的水体中,流动的河流中较为少见;此外,浮萍适宜生长在农田和生活区水体中,工业区附近样本数较少。江苏省夏季浮萍的主要品种为紫萍(Spirodelapolyrrhiza)、青萍(Lemmaminor)、芜萍(Wolffiaarrhiza)和少根紫萍(Spirodelaoligorrhiza),调查期间未发现稀脉浮萍(Lemmaperpusilla)与品藻(Lemmatrisulca)。紫萍和青萍在所调查的每个采样点均有分布,其生长水体的pH值变化范围(4.5~7.5)较大。浮萍生长水环境的氮、磷养分浓度范围很广,铵态氮、硝态氮、总氮、总磷质量浓度范围分别为0~42、0.2—2.0、0.2~45和0.02~13mg·L-1,尚未发现浮萍分布与水体氮、磷含量之间的必然联系。工业区附近水体中常见紫萍与青萍以共生形式存在,偶尔还伴有芜萍。在利用浮萍去除水中氮、磷营养物质时,应优先考虑利用各地当季优势浮萍品种及不同品种浮萍的共生复合系统,保障浮萍的最大生长量以及对水体氮、磷的最大去除率。  相似文献   
39.
Many biodegradation studies have focused on survival of isolated bacteria to increase the bacteria population and subsequently enhance the efficiency of polycyclic aromatic hydrocarbon (PAH) biodegradation. However, there is limited research on enhancing the performance of isolated bacteria through reinoculation. Thus, this study was designed to evaluate the effects of reinoculation on the performance of Sphingobacterium spiritivorum in degradation of phenanthrene contaminated sand. Experiments were performed in three different reactors. Inoculation was performed once (day 0) in reactor 1. In reactor 2, inoculation was performed twice (day 0 and day 5). The bacteria was isolated from reactor 2 and inoculated into reactor 3. The study results show reactor 3 having the highest degradation rate (13.61 mg/kg/day) and percentage removal (95.36 percent). In contrast, without reinoculation in reactor 1, 68.93 percent of phenanthrene was removed. Thus, the performance of S. spiritivorum in phenanthrene degradation can be enhanced through reinoculation. © 2014 Wiley Periodicals, Inc.  相似文献   
40.
Previous investigations revealed a strong magnetic anomaly due to soil magnetic enhancement in the industrialized cross-border area of Upper Silesia (Poland) and Northern Moravia (Czech Republic). Since industrial and urban dusts contain magnetic particles, this soil magnetic enhancement is assumed to be of anthropogenic origin, caused by a high concentration of atmospherically deposited magnetic particles, accumulated in topsoil layers. This assumption is proved by investigations of vertical profiles of magnetic susceptibility along a transect crossing the border area of the two countries. The results show that the population of magnetic minerals in the organic horizon is different from that in the mineral horizons. The vertical distribution of magnetic susceptibility and thermomagnetic analysis suggests negligible lithogenic contribution. The observed relationship between magnetic susceptibility and some heavy metals, confirmed by micromorphological observations and microchemical analysis of magnetic particles separated from the organic horizons of forest topsoil, has proved the usefulness of soil magnetometry for pollution study.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号