全文获取类型
收费全文 | 857篇 |
免费 | 15篇 |
国内免费 | 17篇 |
专业分类
安全科学 | 32篇 |
废物处理 | 33篇 |
环保管理 | 176篇 |
综合类 | 102篇 |
基础理论 | 182篇 |
环境理论 | 1篇 |
污染及防治 | 226篇 |
评价与监测 | 88篇 |
社会与环境 | 31篇 |
灾害及防治 | 18篇 |
出版年
2023年 | 8篇 |
2022年 | 8篇 |
2021年 | 18篇 |
2020年 | 11篇 |
2019年 | 5篇 |
2018年 | 22篇 |
2017年 | 26篇 |
2016年 | 25篇 |
2015年 | 13篇 |
2014年 | 36篇 |
2013年 | 66篇 |
2012年 | 36篇 |
2011年 | 53篇 |
2010年 | 51篇 |
2009年 | 40篇 |
2008年 | 51篇 |
2007年 | 42篇 |
2006年 | 53篇 |
2005年 | 36篇 |
2004年 | 30篇 |
2003年 | 35篇 |
2002年 | 26篇 |
2001年 | 23篇 |
2000年 | 14篇 |
1999年 | 11篇 |
1998年 | 14篇 |
1997年 | 8篇 |
1996年 | 15篇 |
1995年 | 12篇 |
1994年 | 17篇 |
1993年 | 9篇 |
1992年 | 4篇 |
1991年 | 9篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1964年 | 1篇 |
1956年 | 2篇 |
排序方式: 共有889条查询结果,搜索用时 46 毫秒
81.
82.
This study investigates the relationship between characteristics of environmental policy statements and the reputations of ISO 14001 registrars who had performed certification audits of firms operating in mainland China. Three characteristics of environmental policy statements were examined: (1) The conformance of the policy to strict interpretations of the international standard; (2) The policy statement's adherence to the good practice guidelines specified in ISO 14004; and, (3) Self-reported evaluations of the policy statement's effectiveness as implemented. Data from 106 facilities in Beijing, Shanghai and Guangzhou reveal that registrar quality has a relatively weak, positive relationship with conformance to both ISO 14001 standards and to ISO 14004 guidelines, but no relationship was observed with the self-reported data. Additional findings are that the use of foreign registrars is significantly associated with the adoption of ISO 14004 guidelines and that conformance with ISO 14001 standards is somewhat higher for international joint ventures and foreign-owned firms than for state-owned enterprises. 相似文献
83.
Two novel solid-state 13C nuclear magnetic resonance (NMR) spectroscopic techniques, PSRE (proton spin relaxation editing) and RESTORE [Restoration of Spectra via T(CH) and T(1rho)H (T One Rho H) Editing], were used to provide detailed chemical characterization of the organic matter from six Australian sewage sludges. These methods were used to probe the submicrometer heterogeneity of sludge organic matter, and identify and quantify spatially distinct components. Analysis of the T1H relaxation behavior of the sludges indicated that each sludge contained two types of organic domains. Carbon-13 PSRE NMR subspectra were generated to determine the chemical nature of these domains. The rapidly relaxing component of each sludge was rich in protein and alkyl carbon, and was identified as dead bacterial material. The slowly relaxing component of each sludge was rich in carbohydrate and lignin structures, and was identified as partly degraded plant material. The bacterial domains were shown, using the RESTORE technique, to also have characteristically rapid T(1rho)H relaxation rates. This rapid T(1rho)H relaxation was identified as the main cause of underrepresentation of these domains in standard 13C cross polarization (CP) NMR spectra of sludges. The heterogeneous nature of sewage sludge organic matter has implications for land application of sewage sludge, since the two components are likely to have different capacities for sorbing organic and inorganic toxicants present in sewage sludge, and will decompose at different rates. 相似文献
84.
Carmen A. Lebrón Timothy McHale Robroy Young Dale Williams Matthew G. Bogaart David W. Major Michaye L. McMaster Ian Tasker Naji Akladiss 《补救:环境净化治理成本、技术与工艺杂志》2007,17(2):5-17
An Interstate Technology and Regulatory Council (ITRC) forum was recently held that focused on six case studies in which bioremediation of dense nonaqueous‐phase liquids (DNAPLs) was performed; the objective was to demonstrate that there is credible evidence for bioremediation as a viable environmental remediation technology. The first two case studies from the forum have been previously published; this third case study involves a pilot‐scale demonstration that investigated the effects of biological activity on enhancing dissolution of an emplaced tetrachloroethene (PCE) DNAPL source. It used a controlled‐release test cell with PCE as the primary DNAPL in a porous media groundwater system. Both laboratory tests and a field‐scale pilot test demonstrated that bioaugmentation can stimulate complete dechlorination to a nontoxic end product and that the mass flux from a source zone increases when biological dehalorespiration activity is enhanced through nutrient (electron donor) addition and bioaugmentation. All project goals were met. Important achievements include demonstrating the ability to degrade a PCE DNAPL source to ethene and obtaining significant information on the impacts to the microbial populations and corresponding isotope enrichments during biodegradation of a source area. © 2007 Wiley Periodicals, Inc. 相似文献
85.
86.
87.
Eucalyptus forest; and in the composition of understorey herbs, sedges, and grasslands. Pollen concentration and charcoal and organic
content also exhibit post-European changes. Thus, pollen analysis provides a technique for determining changes in sediment
budgets and identifying major vegetation changes in floodplains. 相似文献
88.
89.
90.