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   1600篇
  免费   133篇
  国内免费   138篇
安全科学   204篇
废物处理   30篇
环保管理   757篇
综合类   295篇
基础理论   278篇
污染及防治   155篇
评价与监测   85篇
社会与环境   40篇
灾害及防治   27篇
  2023年   25篇
  2022年   26篇
  2021年   42篇
  2020年   48篇
  2019年   45篇
  2018年   29篇
  2017年   52篇
  2016年   60篇
  2015年   68篇
  2014年   67篇
  2013年   79篇
  2012年   63篇
  2011年   105篇
  2010年   61篇
  2009年   123篇
  2008年   82篇
  2007年   77篇
  2006年   62篇
  2005年   77篇
  2004年   56篇
  2003年   69篇
  2002年   61篇
  2001年   48篇
  2000年   59篇
  1999年   52篇
  1998年   47篇
  1997年   25篇
  1996年   39篇
  1995年   24篇
  1994年   19篇
  1993年   17篇
  1992年   13篇
  1991年   11篇
  1990年   9篇
  1989年   14篇
  1988年   11篇
  1987年   9篇
  1986年   6篇
  1985年   7篇
  1984年   5篇
  1983年   5篇
  1982年   10篇
  1981年   9篇
  1980年   13篇
  1979年   15篇
  1978年   11篇
  1977年   4篇
  1975年   2篇
  1974年   2篇
  1970年   2篇
排序方式: 共有1871条查询结果,搜索用时 15 毫秒
981.
邹锐  董云仙  颜小品  赵磊  贺彬  刘永 《环境科学》2011,32(11):3193-3199
以云南省程海为例,基于CE-QUAL-W2计算平台开发了水动力-水质模型.由于程海现有的数据不足以支撑开发可靠的流域水文与污染物负荷模型,为弥补由此引起的水质模型边界条件缺失的限制,本研究提出了基于逆向模拟与遗传算法的多模式负荷-参数识别方法来实现对水质模型的校正和鲁棒校验.应用校验后的模型对程海不同水位调控情景的水质...  相似文献   
982.
以昆明市工业区为试点,将2009年作为基准年,2015年作为情景年,利用Aermod模型系统以及相关数据对工业区内SO2环境浓度进行预测.模拟情景的建立基于“十二五”工业源减排规划.研究发现工业源减排措施将对区域SO2浓度有显著影响,降幅最高可达13%.2015年不同模拟时段的SO2等浓度下分布面积均较2009年有明显减小,高浓度地区个数变少,这种现象也出现在污染源非集中地区.研究结果表明利用模型预测可有效分析减排政策对工业区内环境质量状况的影响,有助于建立减排响应机制.  相似文献   
983.
Physiologically based pharmacokinetic (PBPK) models were developed in order to translate external concentrations into internal dose estimates, but most PBPK models were developed for younger adults. A set of physiological parameters for ages 65, 75, and 85 of both genders were developed and were used with previously established human PBPK models of exposure to toluene and perchloroethylene (PERC) in order to investigate internal dose changes with increasing age. The predicted compartmental concentrations of toluene and PERC for aged adults were lower than predicted concentrations for younger adults, and this suggests that body composition changes with aging do not increase internal doses of inhaled toxicants alone after acute exposure. Hence, susceptibility to either toxicant was not expected to increase solely based on the physiological changes associated with aging. Predictions for a metabolite of PERC, however, were similar in magnitude across ages, which may lead to enhanced susceptibility if metabolic capacity changes with aging.  相似文献   
984.
A conceptual mathematical model was used to evaluate the design parameters of a combined ultraviolet (UV)-biofilter system, and perform a cost analysis. Results showed that the UV light source strength and the gas residence times in the UV system (UVRT) and biofilter (EBRT) had positive effects on the overall chlorobenzene removal efficiency of the system. High ratio of UVRT to EBRT improved the removal efficiency, suggesting that the UV system has a greater effect on the overall performance of the system compared with the biofilter. Analysis of the capital and operating costs showed that the capital costs of the standalone biofilter system were much higher than those of the standalone UV system. However, the biofilter operating costs were lower than those of the UV system. The operating costs of the combined UV-biofilter system increased with increasing UVRT/EBRT ratio, whereas its capital costs decreased.  相似文献   
985.
To develop a predictive dust explosion model or theory many considerations of the interaction between several complex multiscale processes are required. Due to practical considerations only some of the processes may be fully resolved, while the rest must be approximated or neglected. The current study focuses on constructing an organizational framework for dust explosion model development. The framework is organized based on progression of the explosion in time and geometric scale of the important features. Suggested methodologies are given to investigate the small-scale features and develop feed-forward approximations for predictive models at the larger system-scale. The concepts developed through constructing the organizational framework are applied to closed volume dust explosion testing and classification of several sources of experimental variance for this system is given.  相似文献   
986.
随着矿业的快速发展,Surpac,Dimine,3DMine等三维矿业软件在矿业领域得到了广泛的应用。为进一步完善自主研发的采空区激光扫描三维精确建模信息系统功能,在解析stl,dxf及dtm格式文件的数据结构及其三维实体数据存储规律的基础上,成功地开发了基于上述三种实体模型存储文件格式的采空区三维实体模型交互接口,实现了信息系统与目前主流三维矿业软件之间三维实体模型的交互。实用表明,所开发的接口能有效实现信息系统与其他三维矿业软件之间采空区三维模型的交互与共享,进一步完善了信息系统的模型数据输入输出功能,提高了其应用价值。  相似文献   
987.
We coupled rainfall–runoff and instream water quality models to evaluate total suspended solids (TSS) in Wissahickon Creek, a mid‐sized urban stream near Philadelphia, Pennsylvania. Using stormwater runoff and instream field data, we calibrated the model at a subdaily scale and focused on storm responses. We demonstrate that treating event mean concentrations as a calibration parameter rather than a fixed input can substantially improve model performance. Urban stormwater TSS concentrations vary widely in time and space and are difficult to represent simply. Suspended and deposited sediment pose independent stressors to stream biota and model results suggest that both currently impair stream health in Wissahickon Creek. Retrofitting existing detention basins to prioritize infiltration reduced instream TSS loads by 20%, suggesting that infiltration mitigates sediment more effectively than detention. Infiltrating stormwater from 30% of the watershed reduced instream TSS loads by 47% and cut the frequency of TSS exceeding 100 mg/L by half. Settled loads and the frequency of high TSS values were reduced by a smaller fraction than suspended loads and duration at high TSS values. A widely distributed network of infiltration‐focused projects is an effective stormwater management strategy to mitigate sediment stress. Coupling rainfall–runoff and water quality models is an important way to integrate watershed‐wide impacts and evaluate how management directly affects urban stream health.  相似文献   
988.
The global crisis of the hazardous electronic waste (E-waste) is on the rise due to increasing usage and disposal of electronic devices. A process was developed to treat E-waste in an environmentally benign process. The process consisted of thermal plasma treatment followed by recovery of metal values through mineral acid leaching. In the thermal process, the E-waste was melted to recover the metal values as a metallic mixture. The metallic mixture was subjected to acid leaching in presence of depolarizer. The leached liquor mainly contained copper as the other elements like Al and Fe were mostly in alloy form as per the XRD and phase diagram studies. Response surface model was used to optimize the conditions for leaching. More than 90% leaching efficiency at room temperature was observed for Cu, Ni and Co with HCl as the solvent, whereas Fe and Al showed less than 40% efficiency.  相似文献   
989.
Wastewater irrigation is a re-emerging method for dealing with an area's wastewater, particularly in Northern temperate climates in the U.S. Muskegon, Michigan, typical of a medium-sized Northern urban area, is currently adopting wastewater irrigation to meet its present and future wastewater treatment needs.  相似文献   
990.
Members of the United Nations Economic Commission for Europe (UN-ECE) signed a legally binding protocol on persistent organic pollutants (POPs) in February 1998 under the Convention on Long-Range Transboundary Air Pollution. A treaty that intends to control the production, import, export, disposal and use of toxic chemicals that persist for decades in the environment has been formally signed at a conference in May 2001 in Stockholm. The 2001 POP treaty, like the 1998 LRTAP POP protocol, contains a provision on adding further chemicals to the initial group of twelve or fifteen. The occurrence of a compound or a group of compounds in so called remote and pristine areas, e.g. in the Artic or in the Southern Hemisphere, proves its stability under the chemical and biological conditions of the environment. Compounds identified in this way, in samples taken primarily in very remote regions of the planet, are classified by their environmental fate and global distribution as persistent organic pollutants (POPs), regardless of any political assessments.  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