全文获取类型
收费全文 | 2376篇 |
免费 | 23篇 |
国内免费 | 15篇 |
专业分类
安全科学 | 58篇 |
废物处理 | 168篇 |
环保管理 | 155篇 |
综合类 | 308篇 |
基础理论 | 448篇 |
环境理论 | 2篇 |
污染及防治 | 867篇 |
评价与监测 | 245篇 |
社会与环境 | 149篇 |
灾害及防治 | 14篇 |
出版年
2023年 | 25篇 |
2022年 | 84篇 |
2021年 | 82篇 |
2020年 | 45篇 |
2019年 | 57篇 |
2018年 | 94篇 |
2017年 | 90篇 |
2016年 | 137篇 |
2015年 | 88篇 |
2014年 | 131篇 |
2013年 | 221篇 |
2012年 | 148篇 |
2011年 | 188篇 |
2010年 | 131篇 |
2009年 | 101篇 |
2008年 | 127篇 |
2007年 | 140篇 |
2006年 | 100篇 |
2005年 | 75篇 |
2004年 | 69篇 |
2003年 | 61篇 |
2002年 | 52篇 |
2001年 | 35篇 |
2000年 | 29篇 |
1999年 | 17篇 |
1998年 | 12篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 10篇 |
1994年 | 10篇 |
1993年 | 6篇 |
1992年 | 8篇 |
1990年 | 5篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
1962年 | 1篇 |
1958年 | 1篇 |
1956年 | 1篇 |
1915年 | 1篇 |
排序方式: 共有2414条查询结果,搜索用时 31 毫秒
991.
Ana María Murgida Marcela Hebe González Holm Tiessen 《Regional Environmental Change》2014,14(4):1387-1394
Regional change under agricultural expansion in the Chaco of Argentina is determined by interactions of rainfall change, infrastructure development, socio-economic actions and values, and the social perceptions of change. Our study focused on adaptation in the socio-environmental system which is the key to understanding opportunities, uncertainties and risk in the context of historical change. Change in land use from extensive grazing through mixed farming and on to industrial-scale soybean production was made possible by a trend of increasing rainfall that reduced the risk of crop failure from drought since the 1970s. Rainfall change coincided with a period in which the Chaco forest was suffering extensive degradation from long-term extractive use. The degradation aided agricultural expansion since the degraded state of the ecosystem justified public policies of deforestation. In parallel to these resource-based processes, public policy changed in the late 70s and 80s toward favoring privatization of state land and exclusion of small producers. This permitted the land concentration needed for industrial-scale production. Technological innovation in both water and land resource management reinforced the process of concentration because small producers rarely have the financial or educational capital to develop or implement emerging technologies. One of the results of the intensification and expansion of agriculture is that soil surface sealing, waterlogging and flood risk are now effective at a landscape scale. To address these risks, private enterprise and government efforts must now come together toward innovative policies in integrated landscape management. 相似文献
992.
Marie Lefrancq Sylvain Payraudeau Antonio Joaquín García Verdú Elodie Maillard Maurice Millet Gwenaël Imfeld 《Environmental science and pollution research international》2014,21(7):4871-4882
Surface runoff and erosion during the course of rainfall events are major processes of pesticides transport from agricultural land to aquatic ecosystem. These processes are generally evaluated either at the plot or the catchment scale. Here, we compared at both scales the transport and partitioning in runoff water of two widely used fungicides, i.e., kresoxim-methyl (KM) and cyazofamid (CY). The objective was to evaluate the relationship between fungicides runoff from the plot and from the vineyard catchment. The results show that seasonal exports for KM and CY at the catchment were larger than those obtained at the plot. This underlines that non-target areas within the catchment largely contribute to the overall load of runoff-associated fungicides. Estimations show that 85 and 62 % of the loads observed for KM and CY at the catchment outlet cannot be explained by the vineyard plots. However, the partitioning of KM and CY between three fractions, i.e., the suspended solids (>0.7 μm) and two dissolved fractions (i.e., between 0.22 and 0.7 µm and <0.22 µm) in runoff water was similar at both scales. KM was predominantly detected below 0.22 μm, whereas CY was mainly detected in the fraction between 0.22 and 0.7 μm. Although KM and CY have similar physicochemical properties and are expected to behave similarly, our results show that their partitioning between two fractions of the dissolved phase differs largely. It is concluded that combined observations of pesticide runoff at both the catchment and the plot scales enable to evaluate the sources areas of pesticide off-site transport. 相似文献
993.
Pablo Ferrer María Cambra-López Alba Cerisuelo David S. Peñaranda Verónica Moset 《Waste management (New York, N.Y.)》2014,34(1):196-203
Anaerobic co-digestion of pig slurry with four agricultural substrates (tomato, pepper, persimmon and peach) was investigated. Each agricultural substrate was tested in co-digestion with pig slurry at four inclusion levels: 0%, 15%, 30% and 50%. Inclusion levels consisted in the replacement of the volatile solids (VS) from the pig slurry with the VS from the agricultural substrate. The effect of substrate type and inclusion level on the biochemical methane potential (BMP) was evaluated in a batch assay performed at 35 °C for 100 days. Agricultural substrate’s chemical composition was also analyzed and related with BMP. Additionally, Bacteria and Archaea domains together with the four main methanogenic archaeal orders were quantified using quantitative real-time TaqMan polymerase chain reaction (qPCR) at the end of the experiment to determine the influence of agricultural substrate on sludge’s microbial composition. Results showed that vegetable substrates (pepper and tomato) had higher lipid and protein content and lower carbohydrates than fruit substrates (persimmon and peach). Among substrates, vegetable substrates showed higher BMP than fruit substrates. Higher BMP values were obtained with increasing addition of agricultural substrate. The replacement of 50% of VS from pig slurry by tomato and pepper increased BMP in 41% and 44%, respectively compared with pig slurry only. Lower increments in BMP were achieved with lower inclusion levels. Results from qPCR showed that total bacteria and total archaea gene concentrations were similar in all combinations tested. Methanomicrobiales gene concentrations dominated over the rest of individual archaeal orders. 相似文献
994.
UV-fluorescence spectroscopy method with synchronous mode of scanning was used to characterize the types of aromatic hydrocarbons in surface sediments. the sampling stations were located on two transverses between Yugoslavian and the Italian coasts in the middle of the Adriatic Sea. the preparation of sediment samples was made according to IOC/UNESCO (1982). Synchronous excitation/emission scanning were done at wavelengths from 236/260 to 516/540 nm. Since the wavelength of maximum emission is a function of fused aromatic rings in a molecule, the fluorescence spectra of each sample were divided into three intervals: 300-340, 340-400, over 400 nm, corresponding to compounds with 2, 3 and 4,5 and more rings respectively.
Large qualitative differences were established between sediment samples. PAH with 5 and more rings are more prevalent near the Italian coast. 相似文献
Large qualitative differences were established between sediment samples. PAH with 5 and more rings are more prevalent near the Italian coast. 相似文献
995.
Juan A. Correa Paloma González Pablo Sánchez Jorge Muñoz María C. Orellana 《Environmental monitoring and assessment》1996,40(1):41-54
This study evaluated the responses of wild, adult plants of Enteromorpha compressa, and their progeny, to various copper concentrations. Experiments were designed to test the hypotheses that: 1) individuals of E. compressa from Caleta Palito, a copper-enriched coastal locality, tolerate higher copper concentrations than those from a place with no history of copper pollution and 2) such copper tolerance is under genetic control and therefore, was an inherited character. Our results indicate that algae which inhabit a copper-enriched environment tolerate higher concentrations of copper than those from waters with low copper concentrations. On the other hand, our results suggest that generalizations regarding heritability of the tolerance to copper do not apply to the Chilean E. compressa, as no differences in growth or rhizoid production were found between the progeny from Caleta Palito and Caleta Zenteno. These findings are an indication that heritability and adaptation may represent alternative strategies used by different populations of the same algal species to tolerate copper. 相似文献
996.
997.
998.
Dr Françoise Muller Laurence Bussières Marie-Christine Pèlissier Jean-François Oury Claire Boué Serge Uzan André Boué 《黑龙江环境通报》1994,14(7):633-636
In Down syndrome screening by maternal serum human chorionic gonadotropin (hCG) determination at 15, 16, 17, and 18 weeks of gestation, we prospectively examined 23 369 sera from white (21 549), North African (970), black African (525), and Asian (325) patients. When expressed as multiples of the median (MOM), no difference was observed between white, North African, and black African patients. However, higher serum hCG concentrations were noted in Asians, for whom we therefore recommend correction of hCG values before calculation of the risk of Down syndrome. 相似文献
999.
Livia Poenaru Christine Mezard Said Akli Jean-François Oury Yves Dumez Joëlle Boue 《黑龙江环境通报》1990,10(4):231-235
We investigated the possibility of prenatal diagnosis of mucolipidosis type II (ML II) by lysosomal enzyme determination on amniotic fluid obtained at 11 weeks of gestation in three pregnancies at risk. Diagnosis of ML II was made in one case on the basis of increased levels of five lysosomal enzymes tested. The diagnosis was confirmed on cultured chorionic cells, their cultured medium, 17–week amniotic fluid, and fetal plasma obtained for confirmation prior to the termination of pregnancy. 相似文献
1000.
Santiago Beguería Juan I.López-Moreno Adrián Lorente Manuel Seeger José M.García-Ruiz 《Ambio-人类环境杂志》2003,32(4):283-286
在地中海国家扩大灌溉土地的面积,应当考虑气候与土地利用变化对水资源的影响.本文利用降水和温度资料,分析了20世纪中叶以来西班牙比利牛斯山脉中部流域径流的变化趋势.降水与径流之间关系的年变化表明,径流在所研究期间的后半时段相对较低,这一趋势与土地利用变化一致.在月水平上,降水量在10月、4月和7月明显增加,而在3月则有下降;温度在1月和2月有所增加,而在4月则趋于下降.但过去50年间径流在大部分月份中呈显著下降趋势,土地利用和植被覆盖的变化是解释年平均径流下降大约30%的惟一非气候因素. 相似文献