全文获取类型
收费全文 | 455篇 |
免费 | 8篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 24篇 |
废物处理 | 11篇 |
环保管理 | 92篇 |
综合类 | 57篇 |
基础理论 | 133篇 |
污染及防治 | 103篇 |
评价与监测 | 20篇 |
社会与环境 | 15篇 |
灾害及防治 | 12篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 12篇 |
2019年 | 7篇 |
2018年 | 14篇 |
2017年 | 7篇 |
2016年 | 10篇 |
2015年 | 12篇 |
2014年 | 15篇 |
2013年 | 38篇 |
2012年 | 13篇 |
2011年 | 16篇 |
2010年 | 18篇 |
2009年 | 12篇 |
2008年 | 13篇 |
2007年 | 16篇 |
2006年 | 16篇 |
2005年 | 17篇 |
2004年 | 9篇 |
2003年 | 13篇 |
2002年 | 12篇 |
2001年 | 27篇 |
2000年 | 12篇 |
1999年 | 14篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 10篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1977年 | 5篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1967年 | 2篇 |
排序方式: 共有467条查询结果,搜索用时 109 毫秒
311.
312.
G. L. Boyer J. J. Sullivan R. J. Andersen F. J. R. Taylor P. J. Harrison A. D. Cembella 《Marine Biology》1986,93(3):361-369
Procedures have been developed for the extraction and high-performance liquid chromatography (HPLC) analysis of paralytic shellfish poisoning (PSP) toxins from Protogonyaulax spp. grown in batch culture. Using these procedures, the toxin content of two isolates of P. tamarensis (NEPCC 183 and 255) and one isolate of P. catenella (NEPCC 355) were examined. Total toxin and individual toxin concentrations were measured for each isolate during the exponential and stationary phases of growth in batch culture. The total toxicity of each isolate as measured by HPLC analysis was found to agree with toxicity as determined by the standard mouse bioassay. Two of the isolates (255 and 355) were found to be toxic and the third (183) was non-toxic. The toxic isolates (255 and 355) both showed higher average total PSP toxin content during the exponential phase (35 and 23 fmol toxin cell-1, respectively) than during the stationary phase (21 and 8 fmol toxin cell-1, respectively). These cultures differed dramatically in their toxin composition. P. tamarensis (255) contained a large proportion of the N(21) sulfo toxins (B1, B2, C1, C2) while P. catenella (355) contained primarily Gonyautoxins 1 through 4. The percent composition of individual toxins was found to be constant throughout the growth cycle for both toxic isolates, even though the total toxin concentration varied. Our results suggest that PSP toxin profiles might be useful as chemotaxonomic indicators. 相似文献
313.
The Influence of Urban Density and Drainage Infrastructure on the Concentrations and Loads of Pollutants in Small Streams 总被引:14,自引:0,他引:14
Effective water quality management of streams in urbanized basins requires identification of the elements of urbanization that contribute most to pollutant concentrations and loads. Drainage connection (the proportion of impervious area directly connected to streams by pipes or lined drains) is proposed as a variable explaining variance in the generally weak relationships between pollutant concentrations and imperviousness. Fifteen small streams draining independent subbasins east of Melbourne, Australia, were sampled for a suite of water quality variables. Geometric mean concentrations of all variables were calculated separately for baseflow and storm events, and these, together with estimates of runoff derived from a rainfall-runoff model, were used to estimate mean annual loads. Patterns of concentrations among the streams were assessed against patterns of imperviousness, drainage connection, unsealed (unpaved) road density, elevation, longitude (all of which were intercorrelated), septic tank density, and basin area. Baseflow and storm event concentrations of dissolved organic carbon (DOC), filterable reactive phosphorus (FRP), total phosphorus (TP) and ammonium, along with electrical conductivity (EC), all increased with imperviousness and its correlates. Hierarchical partitioning showed that DOC, EC, FRP, and storm event TP were independently correlated with drainage connection more strongly than could be explained by chance. Neither pH nor total suspended solids concentrations were strongly correlated with any basin variable. Oxidized and total nitrogen concentrations were most strongly explained by septic tank density. Loads of all variables were strongly correlated with imperviousness and connection. Priority should be given to low-impact urban design, which primarily involves reducing drainage connection, to minimize urbanization-related pollutant impacts on streams. 相似文献
314.
This paper presents as case studies some New Zealand local government sustainable development initiatives in cleaner production and civic building design. From a series of structured interviews with key players, it describes key motivators and demotivators and puts these in the context of behaviour change theory. These enable a set of actions for local government to be developed that, if applied, could result in an advancement of the sustainable development agenda. However, other critical factors are given that are external to these actions and on which their overall success is dependent. In reviewing these factors as a group we conclude that far greater understanding of the partnership formation process and its dynamic in engendering successful sustainable development decision-making processes is crucial to move beyond the rhetoric of partnerships and enter the more complex and difficult world of truly participatory approaches. 相似文献
315.
Control of Tamarix in the Western United States: Implications for Water Salvage, Wildlife Use, and Riparian Restoration 总被引:1,自引:0,他引:1
Shafroth PB Cleverly JR Dudley TL Taylor JP van Riper C Weeks EP Stuart JN 《Environmental management》2005,35(3):231-246
Non-native shrub species in the genus Tamarix (saltcedar, tamarisk) have colonized hundreds of thousands of hectares of floodplains, reservoir margins, and other wetlands in western North America. Many resource managers seek to reduce saltcedar abundance and control its spread to increase the flow of water in streams that might otherwise be lost to evapotranspiration, to restore native riparian (streamside) vegetation, and to improve wildlife habitat. However, increased water yield might not always occur and has been substantially lower than expected in water salvage experiments, the potential for successful revegetation is variable, and not all wildlife taxa clearly prefer native plant habitats over saltcedar. As a result, there is considerable debate surrounding saltcedar control efforts. We review the literature on saltcedar control, water use, wildlife use, and riparian restoration to provide resource managers, researchers, and policy-makers with a balanced summary of the state of the science. To best ensure that the desired outcomes of removal programs are met, scientists and resource managers should use existing information and methodologies to carefully select and prioritize sites for removal, apply the most appropriate and cost-effective control methods, and then rigorously monitor control efficacy, revegetation success, water yield changes, and wildlife use. 相似文献
316.
The European Environment Agency (EEA) is the European Union body dedicated to providing sound, independent information on the environment. It is a major information source for those involved in developing, adopting, implementing and evaluating environmental policy in Europe, and also for the general public. In line with its mandate, the EEA has developed — focused around a set of policy relevant questions — a set of indicators to assess progress in Europe in integrating environmental considerations into the energy sector. Each question is answered through one or more indicators describing the development of the sector in Europe, implications for the environment and links to policy actions. The indicators cover not only the current situation, but also trends and prospects and, most importantly, point to the conditions for change that are needed for progress towards a more sustainable energy policy that benefits the environment. The results of the most recent assessment are presented in this article and show that in many areas of environmental integration there have been some successes, but overall progress to date has been insufficient. Substantial additional action will therefore be required in the future if the European Union is going to move towards a more environmentally sustainable energy system. 相似文献
317.
T. Taylor Eighmy Bradley S. Crannell James E. Krzanowski Leslie G. Butler Frank K. Cartledge Earl F. Emery J. Dykstra Eusden Jr Elisabeth L. Shaw Carl A. Francis 《Waste management (New York, N.Y.)》1998,18(6-8)
The use of soluble PO43− as a heavy metal chemical stabilization agent was evaluated for a dust generated from melting or vitrification of municipal solid waste combustion residues. Vitrification dusts contain high concentrations of volatile elements such as Cl, Na, K, S, Pb, and Zn. These elements are present in the dusts largely as simple salts (e.g. PbCl2, ZnSO4) which are highly leachable. At an experimental dose of 0.4 moles of soluble PO43− per kg of residue, the pH-dependent leaching (pH 5,7,9) showed that the treatment was able to reduce equilibrium concentrations by factors of 3 to 100 for many metals; particularly Cd, Cu, Pb and Zn. Bulk and surface spectroscopies showed that the insoluble reaction products are tertiary metal phosphate [e.g. Zn3(PO4)2] and apatite [e.g. Pb5(PO4)3Cl] family minerals. Geochemical thermodynamic equilibrium modeling showed that apatite family and tertiary metal phosphate phases act as controlling solids for the equilibrium concentrations of Ca2+, Zn2+, Pb2+, Cu2+, and Cd2+ in the leachates during pH-dependent leaching. Both end members and ideal solid solutions were seen to be controlling solids. Soluble phosphate effectively converted soluble metal salts into insoluble metal phosphate phases despite the relatively low doses and dry mixing conditions that were used. Soluble phosphate is an effective stabilization agent for divalent heavy metals in melting dusts where leachable metals are present in high concentrations. 相似文献
318.
The objective of this project was to assess the efficacy of fluorescence in situ hybridization (FISH) with chromosome-specific DNA probes to identify chromosome number in formalin-fixed, paraffin-embedded placental specimens. Using this approach, 75 per cent of the karyotypes in 20 formalin-fixed placental samples (comprising aneuploids, triploids, and normals) were correctly identified. As this technology improves, the ability to obtain information regarding chromosomal abnormalities in formalin-fixed, paraffin-embedded placental tissue should improve as well. This technology can potentially provide important cytogenetic information even when fresh tissue is not available for standard karyotypic analysis. 相似文献
319.
Paul G. Kratzer Mitchell S. Golbus Scott E. Monroe David E. Finkelstein Robert N. Taylor M.D Ph.D. 《黑龙江环境通报》1991,11(10):751-763
Immunochemical serum assays for human chorionic gonadotropin (hCG), the free ohCG subunit, and progesterone (P) were considered separately and in combination for their ability to screen for chromosomally abnormal pregnancies in the first trimester. Maternal serum was collected from 141 women undergoing chorionic villus sampling at 9–12 menstrual weeks. Trisomy 21 pregnancies had significantly higher hCG levels, while trisomy 18 and 13 pregnancies had markedly lower hCG and progesterone levels than those of chromosomally normal pregnancies. However, the discrimination of normal from aneuploid pregnancies was poor with either hCG alone, progesterone alone, or free ahCG alone. Much improved discrimination was obtained by combining hCG, free ahCG, and P into an aneuploidy index [(P/hCG)(free ahCG/hCG)]. This index distinguished 9 out of 17 (53 per cent) of the trisomy 21 pregnancies, while only misidentifying 5 out of 112 (4.5 per cent) of the normal pregnancies. The aneuploidy index thus appears promising as a first-trimester biochemical screen for aneuploid pregnancies. 相似文献
320.
N. E. Pierce R. L. Kitching R. C. Buckley M. F. J. Taylor K. F. Benbow 《Behavioral ecology and sociobiology》1987,21(4):237-248
Summary The larvae and pupae of the Australian lycaenid butterfly, Jalmenus evagoras associate mutualistically with ants in the genus Iridomyrmex. Four ant exclusion experiments in three field sites demonstrated that predation and parasitism of J. evagoras are so intense that individuals deprived of their attendant ants are unlikely to survive. Larvae and pupae of J. evagoras aggregate, and the mean number of attendant ants per individual increases with larval age and decreases with group size. Field observations showed that young larvae could gain more attendant ants per individual by joining the average size group of about 4 larvae than by foraging alone. Aggregation behaviour is influenced by ant attendance: young larvae and pupating fifth instars aggregated significantly more often on plants with ants than on plants where ants had been excluded. In return for tending and protecting the larvae, ants were rewarded by food secretions that can amount to as much as 409 mg dry biomass from a single host plant containing 62 larvae and pupae of J. evagoras over a 24 h period. Larval development in the laboratory lasted approximately a month, and larvae that were tended by ants developed almost 5 days faster than larvae that were not tended. However, tended individuals, particularly females, pupated at a significantly lower weight than their untended counterparts, and the adults that eclosed from these pupae were also lighter and smaller. On average, pupae that were tended by ants lost 25% more weight than untended pupae, and in contrast with larvae, they took longer to eclose than pupae that were not tended. These experimental results are discussed in terms of costs and benefits of association for both partners, and of aggregation for the lycaenids. 相似文献