全文获取类型
收费全文 | 917篇 |
免费 | 59篇 |
国内免费 | 188篇 |
专业分类
安全科学 | 71篇 |
废物处理 | 55篇 |
环保管理 | 143篇 |
综合类 | 393篇 |
基础理论 | 189篇 |
污染及防治 | 186篇 |
评价与监测 | 48篇 |
社会与环境 | 41篇 |
灾害及防治 | 38篇 |
出版年
2024年 | 5篇 |
2023年 | 12篇 |
2022年 | 36篇 |
2021年 | 30篇 |
2020年 | 28篇 |
2019年 | 31篇 |
2018年 | 37篇 |
2017年 | 40篇 |
2016年 | 44篇 |
2015年 | 53篇 |
2014年 | 53篇 |
2013年 | 94篇 |
2012年 | 67篇 |
2011年 | 79篇 |
2010年 | 49篇 |
2009年 | 55篇 |
2008年 | 68篇 |
2007年 | 50篇 |
2006年 | 38篇 |
2005年 | 36篇 |
2004年 | 16篇 |
2003年 | 27篇 |
2002年 | 28篇 |
2001年 | 20篇 |
2000年 | 18篇 |
1999年 | 12篇 |
1998年 | 22篇 |
1997年 | 6篇 |
1996年 | 10篇 |
1995年 | 9篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1974年 | 4篇 |
1973年 | 5篇 |
1972年 | 3篇 |
排序方式: 共有1164条查询结果,搜索用时 78 毫秒
831.
探讨了以VB可视化集成环境为平台,在Windows操作系统下开发空气污染指数计算与分析系统的基本模型和方法,指出开发空气污染指数计算与分析系统的关键是建立可视化用户界面和相应的事件驱动过程的代码编写,阐述了空气污染指数计算与分析系统的优越性,列出了系统功能的主要内容和开发方法,并且简单介绍了空气污染指数的算法。 相似文献
832.
Scenario‐Based and Scenario‐Neutral Assessment of Climate Change Impacts on Operational Performance of a Multipurpose Reservoir 下载免费PDF全文
Allison G. Danner Mohammad Safeeq Gordon E. Grant Charlotte Wickham Desirée Tullos Mary V. Santelmann 《Journal of the American Water Resources Association》2017,53(6):1467-1482
Scenario‐based and scenario‐neutral impacts assessment approaches provide complementary information about how climate change‐driven effects on streamflow may change the operational performance of multipurpose dams. Examining a case study of Cougar Dam in Oregon, United States, we simulated current reservoir operations under scenarios of plausible future hydrology. Streamflow projections from the CGCM3.1 general circulation model for the A1B emission scenario were used to generate stochastic reservoir inflows that were then further perturbed to simulate a potentially drier future. These were then used to drive a simple reservoir model. In the scenario‐based analysis, we found reservoir operations are vulnerable to climate change. Increases in fall and winter inflow could lead to more frequent flood storage, reducing flexibility to store incoming flood flows. Uncertainty in spring inflow volume complicates projection of future filling performance. The reservoir may fill more or less often, depending on whether springs are wetter or drier. In the summer, drawdown may occur earlier to meet conservation objectives. From the scenario‐neutral analysis, we identified thresholds of streamflow magnitude that can predict climate change impacts for a wide range of scenarios. Our results highlight projected operational challenges for Cougar Dam and provide an example of how scenario‐based and scenario‐neutral approaches may be applied concurrently to assess climate change impacts. 相似文献
833.
834.
本文首先就辐射环境监测数据合理性问题进行了分析,然后提出了几点应对措施以保证监测数据的准确性、一致性以及溯源性,希望能够推动辐射环境监测工作的稳步发展。 相似文献
835.
Han B Jafarpour B Gallagher VN Imhoff PT Chiu PC Fluman DA 《Waste management (New York, N.Y.)》2006,26(4):344-355
Seven pilot-scale partitioning gas tracer tests (PGTTs) were conducted to assess the accuracy and reproducibility of this method for measuring water in municipal solid waste landfills. Tests were conducted in the same location over a 12-month period, and measured moisture conditions ranged from possible dry waste to refuse with a moisture content of 24.7%. The final moisture content of 24.7% was in reasonable agreement with gravimetric measurements of excavated refuse, where the moisture content was 26.5+/-6.0 CI%. Laboratory tests were used to assess the utility of the PGTT for measuring water in small pores, water sorbed to solid surfaces, and the influence of dry waste on PGTTs. These experiments indicated that when refuse surfaces are not completely solvated with water, PGTTs may produce misleading results (negative estimates) of water saturation and moisture content. 相似文献
836.
Chelsea Leishman Ellen E. Widdup Dean M. Quesnel Gordon ChuaLisa M. Gieg Marcus A. Samuel Douglas G. Muench 《Chemosphere》2013
Oil sands mining in the Athabasca region of northern Alberta results in the production of large volumes of oil sands process-affected water (OSPW). We have evaluated the effects of OSPW, the acid extractable organic (AEO) fraction of OSPW, and individual naphthenic acids (NAs) on the germination and development of the model plant, Arabidopsis thaliana (Arabidopsis). The surrogate NAs that were selected for this study were petroleum NAs that have been used in previous toxicology studies and may not represent OSPW NAs. A tricyclic diamondoid NA that was recently identified as a component of OSPW served as a model NA in this study. Germination of Arabidopsis seeds was not inhibited when grown on medium containing up to 75% OSPW or by 50 mg L−1 AEO. However, simultaneous exposure to three simple, single-ringed surrogate NAs or a double-ringed surrogate NA had an inhibitory effect on germination at a concentration of 10 mg L−1, whereas inhibition of germination by the diamondoid model NA was observed only at 50 mg L−1. Seedling root growth was impaired by treatment with low concentrations of OSPW, and exposure to higher concentrations of OSPW resulted in increased growth inhibition of roots and primary leaves, and caused bleaching of cotyledons. Treatment with single- or double-ringed surrogate NAs at 10 mg L−1 severely impaired seedling growth. AEO or diamondoid NA treatment was less toxic, but resulted in severely impaired growth at 50 mg L−1. At low NA concentrations there was occasionally a stimulatory effect on root and shoot growth, possibly owing to the broad structural similarity of some NAs to known plant growth regulators such as auxins. This report provides a foundation for future studies aimed at using Arabidopsis as a biosensor for toxicity and to identify genes with possible roles in NA phytoremediation. 相似文献
837.
Carl Ensfield Jay Gordon Jr. Jim Lindner 《Journal of the Air & Waste Management Association (1995)》2013,63(9):1098-1108
Abstract A study was performed at a Gordon-Darby centralized inspection and maintenance (I/M) test lane in Phoenix, AZ, in December 1999 for the purpose of evaluating the accuracy of production Vehicle Mass Analysis System (VMAS) equipment relative to standard IM240 equipment. Simultaneous transient mass measurements were made on random vehicles using VMAS and IM240 systems on two test lanes during regular I/M testing. Cumulative mass emissions for 846 valid tests were correlated using least-squares regression analysis. Correlation indices were >0.99 for both carbon monoxide (CO) and nitric oxide (NO) and 0.93 for hydrocarbon (HC), and the standard errors of regression were 1.38 g/mi, 0.123 g/mi, and 0.245 g/mi for CO, NO, and HC, respectively. These strong correlation results are reflected by high excess emission identification rates of 99.4% for CO, 99.3% for NO, and 94.5% for HC when applying final IM240 cut points with a <2% error of commission for all pollutants. 相似文献
838.
通过批量实验和柱状实验并结合磷的分级提取探究了给水处理厂废弃铁铝泥(ferric-alum water treatment re-siduals,FARs)吸附正磷酸盐的效果。批量实验结果表明,Langmuir和Freundlich方程均能较好地描述FARs对磷的等温吸附过程,且当pH从5增至9时,FARs磷的饱和吸附量从41.68 mg/g减小到17.08 mg/g。pH越低,磷与FARs的结合能力越强。柱状实验结果表明,FARs具有显著的磷吸附能力,在运行的89 d里,磷的去除率保持在80%以上。出水pH与进水相比略有增加,但增加量不会对地表水体造成影响。磷的分级提取结果进一步说明,被吸附的磷主要以释磷风险小的铁铝结合态存在。综合实验结果表明,FARs可以作为高效磷吸附剂应用于地表水除磷。 相似文献
839.
将制备出的聚硅酸铝锌絮凝剂纳米化,在正交实验和单因素优化的基础上,研究了表面活性剂硬脂酸钠的加入量、超声频率、超声时间及投加量对絮凝剂絮凝效果的影响,并且考察了pH、投加量对印染废水的处理效果的影响。结果表明,超声时间对絮凝效果影响最大,超声频率次之,硬脂酸钠含量影响最小。纳米聚硅酸铝锌絮凝剂的最佳制备条件为:表面活性剂硬脂酸钠加入量为0.1%、超声频率为40Hz、超声时间为60min;考虑处理费用,处理印染废水时pH=6~9、投加量为5mL/250mL时效果较好,浊度去除率可达98.5%,色度去除率可达97.4%。 相似文献
840.
从十一五节能目标出发,利用2006~2010年全国30个省区的统计数据,分析了各省区节能效率及绿色距离的变化。结论如下:(1)依据各省区单位GDP能耗、单位IAV能耗和单位GDP电耗数据计算它们的节能量与节能效率,结果发现各省区节能量与节能效率差异较大;(2)利用单位GDP能耗与单位IAV能耗、单位GDP电耗的面板数据,确定了生态省建设的单位IAV能耗、单位GDP电耗标准分别为1.513 7tce和95547度;(3)依据能耗绿色距离和生态化实现度公式,分析了各省区能耗绿色距离和生态化实现度的变化。既是对过去5 a各省区节能效率的回顾性评价,同时也为未来5 a各省区节能降耗提供了参考依据 相似文献