全文获取类型
收费全文 | 7902篇 |
免费 | 68篇 |
国内免费 | 302篇 |
专业分类
安全科学 | 363篇 |
废物处理 | 365篇 |
环保管理 | 789篇 |
综合类 | 1176篇 |
基础理论 | 583篇 |
污染及防治 | 3281篇 |
评价与监测 | 1038篇 |
社会与环境 | 570篇 |
灾害及防治 | 107篇 |
出版年
2024年 | 9篇 |
2023年 | 31篇 |
2022年 | 32篇 |
2021年 | 19篇 |
2020年 | 26篇 |
2019年 | 27篇 |
2018年 | 39篇 |
2017年 | 41篇 |
2016年 | 30篇 |
2015年 | 43篇 |
2014年 | 62篇 |
2013年 | 41篇 |
2012年 | 704篇 |
2011年 | 909篇 |
2010年 | 130篇 |
2009年 | 273篇 |
2008年 | 896篇 |
2007年 | 846篇 |
2006年 | 726篇 |
2005年 | 593篇 |
2004年 | 513篇 |
2003年 | 479篇 |
2002年 | 406篇 |
2001年 | 269篇 |
2000年 | 183篇 |
1999年 | 110篇 |
1998年 | 41篇 |
1997年 | 68篇 |
1996年 | 48篇 |
1995年 | 68篇 |
1994年 | 44篇 |
1993年 | 40篇 |
1992年 | 46篇 |
1991年 | 39篇 |
1990年 | 50篇 |
1989年 | 33篇 |
1988年 | 43篇 |
1987年 | 41篇 |
1986年 | 32篇 |
1985年 | 46篇 |
1984年 | 30篇 |
1983年 | 33篇 |
1982年 | 27篇 |
1981年 | 16篇 |
1980年 | 25篇 |
1979年 | 25篇 |
1978年 | 14篇 |
1977年 | 6篇 |
1975年 | 7篇 |
1974年 | 6篇 |
排序方式: 共有8272条查询结果,搜索用时 31 毫秒
951.
/ Surveys focusing on solid-waste-related issues, conducted over a period of several years, provided data from independent samples of residents of a Midwestern, USA, community. The collection of these data yielded useful information about the relationship between residents' recycling motives and their attitudes toward solid waste management in light of several changes in the solid waste infrastructure of the community over that time. The initial survey assessed baseline beliefs and attitudes, while later surveys were conducted after the implementation of a community educational program and a curbside recycling program. The findings indicated that for recyclers and nonrecyclers, different motives predicted endorsement of solid waste programs and policies. Although a similar percentage of recyclers and nonrecyclers were in support of various proposed programs and policies, concern for the environment was found to be positively related to nonrecyclers' support of proposed programs, particularly before these programs were implemented. Prior to program implementation, motives other than environmental altruism were found to be related to recyclers' support of the programs. Additional findings support the idea that educational programs and increased accessibility to recycling opportunities affect the relationship between people's attitudes toward solid waste management and their recycling motives. 相似文献
952.
/ Marginal aquatic systems (wetlands) of the Po River (Italy) have become the target of a renewed interest because of their value for recreation, natural reserves, and deposits of sand. To preserve these sites, wise management must be the objective of local administrations. In this paper a strategy for the sustainable use of 11 wetlands is presented. It uses simple economic analysis and multiple criteria techniques and provides suggestions to promote sustainability in terms of conservation of natural resources, economic self-sufficiency, and minimization of potential conflicts about the use of the wetlands. In the understanding that sustainability is framed in a long-term perspective, stability analysis is also considered and performed by means of loop analysis, a qualitative technique. Conditions for stability are then discussed about management opportunities. 相似文献
953.
Veihe A 《Environmental management》2000,25(4):393-402
/ Major responsibility for conserving forest biodiversity is often assigned to natural resource agencies. Often unknown is the appropriate administrative context for doing so, especially the organizational location for biodiversity programs in state government, suitable levels of financial and professional investment in biodiversity programs, processes useful for coordinating programs located in different administrative settings, and the effectiveness of biodiversity programs, especially conditions associated with programs judged to be very effective. Focusing on forests, a nationwide survey of 156 forestry agency and biodiversity program administrators in all 50 states was undertaken. Effective forest biodiversity programs were those with a long-range plan, administered as a single organizational unit, located in close organizational proximity to a state's forestry agency, actively providing management practice advice to landowners, administrators, and the public, and firm actions taken to ensure coordination with other natural resource programs. 相似文献
954.
Reinventing Environmental Regulation from the Grassroots Up: Explaining and Expanding the Success of the Toxics Release Inventory 总被引:3,自引:0,他引:3
/ The success of the Toxics Release Inventory (TRI) stands in stark contrast to most other environmental regulations in the United States. Between its inception in 1988 and 1995, releases of chemicals listed on the TRI have declined by 45%. We argue the TRI has achieved this regulatory success by creating a mechanism of "populist maxi-min regulation." This style of regulation differs from traditional command-and-control in several ways. First, the majorrole of public agencies is not to set and enforce standards, but to establish an information-rich context for private citizens, interest groups, and firms to solve environmental problems. Second, environmental "standards" are not determined by expert analysis of acceptable risk, but are effectively set at the levels informed citizens will accept. Third, firms adopt pollution prevention and abatement measures in response to a dynamic range of public pressures rather than to formalized agency standards or governmental sanction. Finally, public pressure ruthlessly focuses on the worst polluters-maximum attention to minimum performers-to induce them to adopt more effective environmental practices. TRI has inadvertently set in motion this alternative style of regulation that has, in turn, dramatically reduced toxics emissions in the United States. By properly understanding the mechanisms that drive TRI's accomplishments, more intentional public policy designs can expand the system of populist maxi-min regulation and achieve even more rapid toxics reduction. 相似文献
955.
PROFILE: Tourism Contribution to Agro-Ecosystems Conservation: The Case of Lesbos Island, Greece 总被引:1,自引:0,他引:1
The objective of this study was to investigate the impact of tourism activities on olive tree cultivation and the human population
of the island of Lesbos. The presence or absence of tourism is related with the maintenance or abandonment of olive tree cultivation
and population changes for each community. A spatial segregation of the island is evident, related to tourist development,
olive tree cultivation, and population change. The results of the study demonstrate that in communities where tourism plays
an important role olive tree cultivation is preserved and the population is stable. The preservation of the agro-ecosystem
is assured while the olive groves remain productive. Simultaneously, the landscape, which provides specific attractions for
tourism, is not altered. 相似文献
956.
The levels of toxaphene congeners, in addition to PCB congeners and organochlorine pesticides, were determined in various fish samples from different Danish waters. While PCB-153 and p,p'-DDE show different levels depending on the fishing area, with highest levels in fish from the Western Baltic Sea, toxaphene was detected in all the samples investigated at a more constant level. The distribution of the three toxaphene congeners Parlar #26, #50 and #62 depends on the fishing area, with the Western Baltic Sea being different from the other waters by having almost equal levels of toxaphene congeners #26 and #50. 相似文献
957.
A method for the congener-specific analysis of toxaphene in eggs of seabirds from a monitoring program from the northern part of Germany was carried out. The method was optimized in most steps of the procedure: injection temperature, HRGC with an HT-8 column, ion source temperature and the MS detection mode NCI/SIM measuring the isotope clusters of [M] , [M-Cl]-, [M-HCl]- and [M-2Cl]-. The suitability of 1,4-exo, 7,8,9,10,10-heptachloro-5-methoxytricyclo [5,2,1,0(2,6)]dec-3,8-diene as internal standard was demonstrated. 14 toxaphenes with Parlar numbers and more than 60 unknown toxaphenes could be identified. Spatial and temporal trends of toxaphene contamination are presented by using the Parlar 22 components standard for quantification. 相似文献
958.
The distribution of arsenic in the stems of fruit trees grown in soils exposed to arsenical pesticides has been studied using neutron activation analysis. The results show arsenic to be confined mainly to heartwood near the pith and active xylem tissue in the most recent annual growth rings. These results suggest that dendroanalysis for arsenic in fruit trees will not yield a reliable chronology of arsenic exposure. 相似文献
959.
Soil organic matter mobilization by root exudates 总被引:15,自引:0,他引:15
In order to study the different soil organic matter mobilisation by agrarian (Zea mais: cultivars Paolo and Sandek) and forest (Picea abies Karst. and Pinus sylvestris L.) root exudates, three different soils (Dystric Spodic Cambisol--S1, Haplic Luvisol--S2 and Calcaric Cambisol--S3) have been considered. Treating the soils with water (control) or plant root exudates, soil organic matter extracts were obtained. The extracts were characterised by hormone-like activities and gas chromatographic/mass spectrometric (GC/MS) measurements. Water extract and plant root exudates exhibited no hormone-like activity, while the other soil-extracts were endowed with a different hormone-like behaviour. GC/MS data indicated that in the acid soils (S1) Sandek and Picea abies exudates showed a greater ability in extracting organic acid isomers (Cl4COOH, Cl5COOH and Cl7COOH), while in neutral soils (S3) all the exudates were active in separating organic acids. In intermediate conditions (S2), Picea abies and Pinus sylvestris exudates liberated C15COOH isomers, Paolo C11COOH isomers, while Sandek was not effective. The different role of plant root exudates in mobilising bio-molecules from the bulk of the soil is proposed. 相似文献
960.
From the complete base set notifications of new substances currently available, we have investigated what effects the choice of using growth rate or biomass in the algal growth inhibition test has on the relative sensitivity of the three aquatic toxicity tests. Both parameters derived from the algal test were more sensitive than either fish or Daphnia tests. Changes in the classification of substances after the removal of either algae, Daphnia or fish data from the base set, when applying current legal practice, occur in 22.9%, 6.6% and 4.8% of the notifications, respectively. When always using growth rate as a parameter, these numbers change to 15.4%, 9.2% and 7.2%, respectively. 相似文献