全文获取类型
收费全文 | 2409篇 |
免费 | 49篇 |
国内免费 | 27篇 |
专业分类
安全科学 | 102篇 |
废物处理 | 96篇 |
环保管理 | 731篇 |
综合类 | 148篇 |
基础理论 | 503篇 |
环境理论 | 1篇 |
污染及防治 | 644篇 |
评价与监测 | 164篇 |
社会与环境 | 77篇 |
灾害及防治 | 19篇 |
出版年
2023年 | 14篇 |
2022年 | 24篇 |
2021年 | 22篇 |
2020年 | 26篇 |
2019年 | 27篇 |
2018年 | 32篇 |
2017年 | 34篇 |
2016年 | 49篇 |
2015年 | 40篇 |
2014年 | 42篇 |
2013年 | 312篇 |
2012年 | 77篇 |
2011年 | 95篇 |
2010年 | 94篇 |
2009年 | 68篇 |
2008年 | 104篇 |
2007年 | 107篇 |
2006年 | 119篇 |
2005年 | 96篇 |
2004年 | 71篇 |
2003年 | 93篇 |
2002年 | 88篇 |
2001年 | 27篇 |
2000年 | 41篇 |
1999年 | 28篇 |
1998年 | 44篇 |
1997年 | 32篇 |
1996年 | 35篇 |
1995年 | 33篇 |
1994年 | 28篇 |
1993年 | 28篇 |
1992年 | 27篇 |
1991年 | 24篇 |
1990年 | 27篇 |
1989年 | 23篇 |
1988年 | 31篇 |
1987年 | 24篇 |
1986年 | 22篇 |
1985年 | 25篇 |
1984年 | 43篇 |
1983年 | 32篇 |
1982年 | 37篇 |
1981年 | 38篇 |
1980年 | 26篇 |
1979年 | 43篇 |
1978年 | 28篇 |
1977年 | 22篇 |
1976年 | 19篇 |
1971年 | 11篇 |
1970年 | 9篇 |
排序方式: 共有2485条查询结果,搜索用时 234 毫秒
931.
Dr. M. J. Bennett F. Allison G. W. Lowther R. G. F. Gray D. I. Johnston J. S. Fitzsimmons N. J. Manning R. J. Pollitt 《黑龙江环境通报》1987,7(2):135-141
A fatal case of medium-chain acyl-coenzyme A dehydrogenase deficiency is described in a patient who presented with hypoglycaemia and a gross non-ketotic dicarboxylic aciduria. Cultured skin fibroblasts released 14CO2 from [1–14C] octanoic acid at half the normal rate. Prenatal diagnosis was undertaken in a subsequent pregnancy in which cultured amniotic fluid cells revealed a marked reduction in octanoate oxidation indicative of an affected fetus. The pregnancy was terminated and the diagnosis was confirmed by enzyme analysis of skin fibroblasts taken from the fetus. The high residual octanoate oxidation by affected fibroblasts together with the absence of any characteristic abnormality of amniotic fluid organic acids are a potential limitation to the reliability of this type of prenatal diagnosis. 相似文献
932.
Since the early 1990s the U.S. government has been developing and implementing public policies that advance the redevelopment of brownfields, and the recent passage of the Small Business Liability Relief and Brownfields Revitalization Act (SBLRBRA) will significantly advance efforts to integrate environmental contamination mitigation and redevelopment. Experience has demonstrated that successful redevelopment requires the collection, analysis, and interpretation of environmental data in a timely and cost‐effective manner in order to allow developers and lenders to efficiently use cleanup resources, develop response strategies that integrate cleanup with redevelopment, and support meaningful outreach to involved stakeholders. Recent advances in the science and technology of site characterization hold the promise of improved site characterization outcomes while saving time and money. One such advancement, the Triad Approach, combines systematic up‐front planning with the use of a dynamic field investigation process and the generation of real time data to allow in‐field decision making on sample location selection. This article describes an application of the Triad Approach to redevelopment of an urban greenway in Trenton, New Jersey. The Triad Approach, initiated through a partnership between the City of Trenton, New Jersey Department of Environmental Protection, New Jersey Institute of Technology, and the U.S. Environmental Protection Agency, demonstrated that this approach could accelerate the characterization of the 60‐acre, 11‐parcel project area. Environmental issues that were solved using the Triad Approach included the delineation of the extent of historic fill, determination of no further action for several areas of concern, detailed investigation of specific impacted areas and the acquisition of sufficient data to allow the city to make important decisions regarding remediation costs and property acquisition. © 2003 Wiley Periodicals, Inc. 相似文献
933.
Rodney L. Clouser William L. Miller 《Journal of the American Water Resources Association》1980,16(3):453-458
ABSTRACT: A study was undertaken to determine the effect of water intensive appliances or activities on household water consumption. Activities included in the study were use of the washing machine, dishwasher, swimming pool, and lawn watering. In the majority of cases these activities increased per capita consumption and were statistically significant. Households included in the study were not familiar with water saving devices available in the retail market. Even if tehse appliances were purchased, private economic benefits to the household would be low due to the inexpensive water charges levied. However, aggregate community benefits could be large if new well drilling cost or increase in storage facilities could be avoided. In order to avoid these increased costs, regulation or subsidy programs may be the most efficient policy alternatives available to the communities. Subsidies and regulation could potentially decrease water use and offer alternatives to increasing the water supply. 相似文献
934.
935.
The Focal-Species Approach and Landscape Restoration: a Critique 总被引:11,自引:0,他引:11
936.
Catherine D. Kashork V. Reid Sutton Jill S. Fonda Allen Deborah E. Schmidt Marisa L. Likhite Lorraine Potocki William E. O'Brien Lisa G. Shaffer 《黑龙江环境通报》2002,22(11):1028-1032
It has been previously reported that a low or absent maternal serum unconjugated estriol (uE3) level is associated with placental steroid sulfatase (STS) deficiency. Here we report a correlation between patients who present with a very low or absent maternal serum uE3 and a deletion of the STS gene as assessed by fluorescence in situ hybridization (FISH). We studied nine prenatal cases that presented to the clinical laboratory with an abnormal triple screen, specifically low or absent maternal serum uE3 and a 46,XY karyotype. FISH analysis showed complete deletion of a probe containing the STS gene in six cases and one case had a partial deletion (reduced but not absent signal). The remaining two cases were not deleted for the STS probe. All mothers tested whose fetus showed a deletion were shown to be STS deletion carriers using FISH. Biochemical analysis was performed on 7/9 prenatal specimens. All fetuses deleted for the STS probe were also found to be deficient for STS by biochemical analysis of cultured amniotic fluid (5/5). Of the two fetuses not deleted for the STS probe, one was deficient for STS activity, while the other had a normal result. The abnormal result of enzyme deficiency by biochemical analysis in a non-deletion case likely represents a mutation in the STS gene, not detectable by this FISH assay. Postnatal FISH confirmation of the STS deletion was performed in 1/7 cases. Clinical follow-up was available for 4/9 cases following birth. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
937.
针对当前社会经济发展中 ,建设有中国特色的城市化问题 ,展开全方位、多视角的分析阐述。指出并纠正了认识上对城市化问题的种种误区。提出中国的城市化发展应该与国情国力、工业化发展形势相协调 ,过程应有序、健康。并认为 :(1)在相当大一段时期内 ,中国城市化水平以界定在5 0 %或 5 5 %为宜 ,而不应该盲目追求西方国家不同国情的高指标、高比例 ;(2 )对城市今后的发展规模应有一个合理限度 ,考虑人口、用地、环境的合理容量 ;(3)小城镇的发展要合理引导、分期分批、有重点地稳步发展 ;(4)乡村城镇化必须发展生态农业与生态工业 ,走集约化、专业化的道路。正确引导中国的城市化进程 ,把城市发展和农村、工业和农业、人口流动、产业政策、区域平衡、科技进步、外向型经济可持续发展等当作整体一盘棋来统筹制定总体战略 相似文献
938.
High-Resolution Vegetation Data for Mangrove Research as Obtained From Aerial Photography 总被引:4,自引:0,他引:4
Anouk Verheyden Farid Dahdouh-Guebas Katrien Thomaes William De Genst Sanath Hettiarachchi Nico Koedam 《Environment, Development and Sustainability》2002,4(2):113-133
In this methodological study, the applicability of aerial photographs for monitoring mangrove vegetation dynamics at high resolution was investigated. Vegetation maps of three mangrove forests in Sri Lanka (Galle, Rekawa and Pambala) were produced based on visual analysis of aerial photographs. The visual analysis was aided by applying an interpretation key constructed during a first fieldwork mission. Image attributes used for the identification of individual trees included: gray values, texture, form and size of the crowns and the presence or absence of a shaded side. For the identification of species assemblages, the vegetation structure (i.e. the distribution of individual trees) appeared to be an important attribute. The accuracy and reliability of the vegetation maps were investigated during a second fieldwork mission. The aerial photographs proved to be very useful for the production of genus-based vegetation maps. The error analysis showed that density estimations (quantitative identification) based on aerial photography was not sufficiently accurate for the objectives of the study, but that the overall identification of vegetation assemblages (qualitative identification) coincided most satisfactory with the ground-truth data. In addition to the applicability of aerial photography in monitoring mangroves, the importance of aerial photography in the management of the mangrove ecosystem is clearly highlighted. 相似文献
939.
Chinese hamsters were exposed for eight hours per day to automotive diesel exhaust emissions which were diluted with air (18 to 1) and had a particulate level of 6.4 mg/m3. Pulmonary function measurements were made after six months exposure. Body weight (BW), lung weight (LW), vital capacity (VC), residual volume by water displacement (RVw) and by gas dilution (RVD), alveolar volume (VA), and carbon monoxide transfer factor (DLCO) were measured. LW showed a significant increase in the diesel exposed animals (P < 0.01) while VC, RVW, and DLCO showed decreases (P < 0.01). Static deflation volume-pressure curves showed depressed deflation volumes for diesel exposed animals when volumes were corrected for body weight and even greater depressed volumes when volumes were corrected for lung weight. However, when volumes were expressed as percent vital capacity, the diesel exposed animals had higher lung volumes at 0 and 5 cm H2O. Results of the pathological examination of the lung tissue will be necessary for final analysis of our findings. However, preliminary interpretation indicates possible emphysematous changes which are compatible with the observed decrease in DLCO. 相似文献
940.
William H. Stickel Lucille F. Stickel Russell A. Dyrland Donald L. Hughes 《Environmental monitoring and assessment》1984,4(2):113-118
Formalin preservation, freezing, spoiling followed by freezing, and phenoxyethanol were compared in terms of concentrations of DDT, DDD, DDE, endrin, and heptachlor epoxide measured in brain, liver and carcass of birds fed dietary dosages of pesticides and in spiked egg homogenate. Phenoxyethanol proved to be an unsatisfactory preservative; the amount of extractable lipid was excessive, and measurements of concentrations in replicates were erratic. Concentrations of residues in formalin-preserved and frozen samples did not differ significantly in any tissue. Percentage lipid in brains and eggs, however, were significantly lower in formalin-preserved samples. Samples of muscle and liver that had been spoiled before freezing yielded less DDD, and muscle samples yielded more DDT than formalin-preserved samples. We conclude that formalin preservation is a satisfactory method for preservation of field samples and that the warming and spoiling of samples that may occur unavoidably in the field will not result in misleading analytical results. 相似文献