全文获取类型
收费全文 | 777篇 |
免费 | 10篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 31篇 |
废物处理 | 23篇 |
环保管理 | 126篇 |
综合类 | 307篇 |
基础理论 | 122篇 |
污染及防治 | 132篇 |
评价与监测 | 31篇 |
社会与环境 | 19篇 |
出版年
2019年 | 6篇 |
2018年 | 10篇 |
2017年 | 13篇 |
2016年 | 12篇 |
2015年 | 19篇 |
2014年 | 19篇 |
2013年 | 38篇 |
2012年 | 22篇 |
2011年 | 23篇 |
2010年 | 23篇 |
2009年 | 26篇 |
2008年 | 35篇 |
2007年 | 23篇 |
2006年 | 33篇 |
2005年 | 22篇 |
2004年 | 14篇 |
2003年 | 17篇 |
2002年 | 28篇 |
2001年 | 11篇 |
2000年 | 21篇 |
1999年 | 18篇 |
1998年 | 6篇 |
1996年 | 6篇 |
1995年 | 9篇 |
1994年 | 7篇 |
1993年 | 8篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1984年 | 6篇 |
1982年 | 8篇 |
1979年 | 5篇 |
1967年 | 7篇 |
1966年 | 6篇 |
1965年 | 5篇 |
1963年 | 9篇 |
1961年 | 7篇 |
1959年 | 6篇 |
1958年 | 8篇 |
1957年 | 5篇 |
1956年 | 10篇 |
1955年 | 12篇 |
1954年 | 10篇 |
1939年 | 10篇 |
1938年 | 8篇 |
1937年 | 5篇 |
1933年 | 6篇 |
1932年 | 6篇 |
1929年 | 5篇 |
1926年 | 5篇 |
1914年 | 5篇 |
排序方式: 共有791条查询结果,搜索用时 78 毫秒
311.
D. Peterson D. Watson W. Winterlin 《Journal of environmental science and health. Part. B》2013,48(6):587-603
Abstract A high‐intensity short‐wavelength UV light system was studied for its ability to degrade the pesticides carbofuran, fenamiphos sulfoxide (nemacur sulfoxide), and propazine in aqueous solutions. Half‐lives, rate constants, and breakdown products were determined for all chemicals. The presence of hydrogen peroxide, an oxidant and potential source of hydroxyl radicals, had no effect on the rate of breakdown of any of the chemicals investigated. Short‐wavelength UV light appears to be solely responsible for the observed pesticide breakdown. The breakdown of all three pesticides followed first order kinetics. Carbofuran, nemacur sulfoxide, and propazine had half lives of 3.9, 1.1, and 3.9 minutes, respectively. Breakdown product analysis was performed using capillary gas chromatography/mass spectrometry. 相似文献
312.
Shoujun Yuan Qiquan Wang Scott R. Yates Nyles G. Peterson 《Journal of environmental science and health. Part. B》2013,48(7):612-620
Oxytetracycline (2-(amino-hydroxy-methylidene)-4-dimethylamino-5,6,10,11,12a-pentahydroxy-6-methyl-4,4a,5,5a-tetrahydrotetracene-1,3,12-trione) is a major member of the tetracycline antibiotics family of which are widely administered to animals in concentrated animal feeding operations for purposes of therapeutical treatment and health protection. With the disposal of animal manure as fertilizer into agricultural land, tetracyclines enter the environment. However, tetracyclines chelate with multivalent cations and proteins, resulting in low extraction efficiencies from animal manure for tetracycline residue analysis. In this study an efficient extraction method for oxytetracycline from steer manure using methanol/water solution amended with chelating organic acid was developed for the analysis of high performance liquid chromatography. The effect of species and amount of amendment acids, shaking time, methanol/water ratio, manure weight, and repeated times of extraction was investigated. It was optimized to amend 2.5 g citric acid and 1.1 g oxalic acid with 10.0 g manure sample in a 50-ml centrifuge tube and extract with 15 ml methanol/water (9:1 in volume) by vigorously shaking for 30 min in a reciprocating shaker. After centrifugation at 11,000 rpm, supernatant is collected. Sample was extracted for a total of 3 times. The developed extraction method was further applied to extract oxytetracycline from fresh and aged cow manure, swine and poultry manure, and soil. Satisfactory recoveries ranging from (84.1 ± 2.4) % to (102.0 ± 3.1) % were obtained, demonstrating that the optimized extraction method is robust for oxytetracycline from different manure sample matrixes. 相似文献
313.
Jose A. Navarro-Cano Bengt Karlsson Diana Posledovich Tenna Toftegaard Christer Wiklund Johan Ehrlén Karl Gotthard 《Ambio》2015,44(1):78-88
Knowledge of how species interactions are influenced by climate warming is paramount to understand current biodiversity changes. We review phenological changes of Swedish butterflies during the latest decades and explore potential climate effects on butterfly–host plant interactions using the Orange tip butterfly Anthocharis cardamines and its host plants as a model system. This butterfly has advanced its appearance dates substantially, and its mean flight date shows a positive correlation with latitude. We show that there is a large latitudinal variation in host use and that butterfly populations select plant individuals based on their flowering phenology. We conclude that A. cardamines is a phenological specialist but a host species generalist. This implies that thermal plasticity for spring development influences host utilization of the butterfly through effects on the phenological matching with its host plants. However, the host utilization strategy of A. cardamines appears to render it resilient to relatively large variation in climate. 相似文献
314.
Sarah-Louise McManus Karl G. Richards Jim Grant Anthony Mannix Catherine E. Coxon 《Environmental monitoring and assessment》2014,186(11):7819-7836
This study explores the associations of pesticide occurrence in groundwater to geological characteristics of the monitoring points (MPs) contributing area. Pesticide analyses were undertaken during a 2-year groundwater monitoring campaign which generated 845 samples. MCPA and mecoprop were the most frequently detected pesticides in groundwater. Each MP (n?=?158) had a specifically delineated zone of contribution (ZOC) and the dominant physical characteristics present from nine national datasets were recorded for each ZOC. Associations between detections in groundwater and the dominant physical characteristic in each MPs ZOC tested were then statistically analyzed using Fisher’s exact test, logistic regression, and multiple logistic regression. The original physical characteristic datasets used that were associated with detections in groundwater were the type of MP, aquifer type, and Quaternary deposit type. Logistic regression revealed that springs, regionally important aquifer types, aquifers with a karstic flow regime, and alkaline Quaternary deposits in existence above karst aquifers in a MP’s ZOC were more likely to have a pesticide detection in groundwater. Multiple regression from this exploratory work showed some mutual dependency between soil association, aquifer type, and the Geological Survey of Ireland groundwater vulnerability map. The combination of national monitoring data and physical attribute datasets can be used to explore key areas where groundwater is more vulnerable to pesticide contamination. 相似文献
315.
316.
317.
318.
An important concern of conservation biologists is determining what conditions most limit the number of individuals in endangered populations. Because time is a constraint, narrowing the search for such factors is beneficial. Toward this end we used broad spatial and temporal data, to test the hypothesis that reproductive success (as measured by juvenile-to-adult ratios) of the endangered Attwater's Prairie Chicken ( Tympanuchus cupido attwateri ) was not equal to that of the nonendangered Greater Prairie Chicken ( T. c. pinnatus ). We then tested the hypotheses that mean clutch size, egg hatchability, nesting success, and number of chicks per brood prior to brood breakup for Attwater's Prairie Chicken were not equal to those of the Greater Prairie Chicken. We found that the mean ratio of juveniles to adults among Attwater's Prairie Chicken was less than that of the Greater Prairie Chicken ( p < 0.011), as would be predicted if reproductive success controls proportional changes in prairie-grouse numbers among years. Mean nesting success (32.2%) and number of chicks per brood prior to brood breakup (4.2) of Attwater's Prairie Chicken were both less than those of the Greater Prairie Chicken (49.5 %, p = 0.0425, and 6.0 p = 0.0001, respectively). We suggest that researchers focus on determining what proportion of Attwater's Prairie Chicken broods survive and why Attwater's Prairie Chicken nesting and brood-rearing success are so poor relative to those of the Greater Prairie Chicken. 相似文献
319.
Using the formulation of latent failure times, the problem of inference on survival time in the presence of competing risks is discussed. Even for the simplified problem where dose and other covariates are fixed, it is not well known that the distributions of the latent failure times are not identifiable from the usual competing risks data. Bounds for the joint survival function and marginal survival functions for the latent failure times are given, and an example illustrates the determination of empirical bounds that estimate the true bounds. In general, the bounds are wide and therefore not very useful. Some alternate approaches are briefly mentioned. 相似文献
320.
L. LaFleur T. Bousquet K. Ramage B. Brunck T. Davis W. Luksemburg B. Peterson 《Chemosphere》1990,20(10-12)
Analysis of 2378-TCDD and 2378-TCDF on the ppq-level in foods with high fat content is described. The migration over twelve days of 2378-TCDD, 2378-TCDF and 1278-TCDF from bleached paperboard cartons into whole milk was found to be exponential with time. A survey of selected fatty foods shows the presence of 2378-TCDD and 2378-TCDF in foodstuff. 相似文献