全文获取类型
收费全文 | 436篇 |
免费 | 3篇 |
国内免费 | 9篇 |
专业分类
安全科学 | 5篇 |
废物处理 | 26篇 |
环保管理 | 29篇 |
综合类 | 85篇 |
基础理论 | 81篇 |
污染及防治 | 156篇 |
评价与监测 | 37篇 |
社会与环境 | 25篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 5篇 |
2022年 | 20篇 |
2021年 | 13篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 16篇 |
2017年 | 19篇 |
2016年 | 26篇 |
2015年 | 17篇 |
2014年 | 25篇 |
2013年 | 27篇 |
2012年 | 30篇 |
2011年 | 43篇 |
2010年 | 25篇 |
2009年 | 22篇 |
2008年 | 23篇 |
2007年 | 38篇 |
2006年 | 20篇 |
2005年 | 20篇 |
2004年 | 12篇 |
2003年 | 8篇 |
2002年 | 11篇 |
2001年 | 1篇 |
2000年 | 4篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1989年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有448条查询结果,搜索用时 15 毫秒
61.
62.
63.
To evaluate factors regulating RNA content (RNA, μg RNA female−1) – egg production rate (EPR, eggs female−1 day−1) relationship and to develop a model for in situ egg production rate estimates for Acartia bifilosa, we (1) measured EPR and RNA in females sampled at geographically distant areas at varying temperature (T, °C), (2) determined environmental (station, season, and T), endogenous (prosome length (PL), mm and EPR) variables that influence RNA levels, and (3) explored a set of multiple regression
models to predict EPR from RNA, PL, station, season, and T. Egg production experiments were carried out in spring and summer 2005 in the Gulf of Finland and in the western part of
the northern Baltic proper. We found that up to 88% of the RNA variation could be explained by variations in PL, EPR, and
season/T. In explaining the RNA variability, PL played a major role followed in order of importance by EPR and season/T. Further, PL, RNA, and season/T explained up to 53% of the variation in EPR, nearly half of which is explained by RNA alone. The effect of spatial origin
was never significant, suggesting that the derived relationships are general for A. bifilosa inhabiting northern Baltic proper.
An erratum to this article is available at . 相似文献
64.
65.
Abstract In summer 1997, gelatinous aggregates appeared in the Adriatic Sea, covering large areas of the northern basin. This study deals with the comparison between the biochemical composition of the sedimentary organic matter in summer, 1996 (when no aggregates appeared), and in summer, 1997 (during the appearance of aggregates). the biochemical composition of organic matter in surface sediments (determined in terms of proteins, carbohydrates, lipids, phytopigments and nucleic acids) has been investigated in two areas along the coast of the NW-Adriatic Sea in order to characterize benthic processes during aggregate deposition on the sea floor. During mucilage accumulation, a significant increase of biochemical compounds was observed, and chlorophyll-a and carbohydrate concentrations doubled their concentrations. in contrast, protein concentrations decreased, so that overall biopolymeric carbon content (expressed as the sum of lipid, protein and carbohydrate carbon equivalents) did not display significant differences between sampling periods (1579.3 in June, 1996 1678.8 μgCg?1 and June, 1997). the protein to carbohydrate ratio decreased from 4.9 in June, 1996 to 1.8 in June, 1997. Mucilage production in June, 1997, modified significantly the biochemical composition of the sedimentary OM, thus affecting the potential availability of OM to benthic consumers. We hypothesise that the production of highly refractory composition of the sedimentary OM during mucilage accumulation might have an important biogeochemical implications. 相似文献
66.
67.
Giuseppe Vaccari Giulio Sgualdino Elena Tamburini Giorgio Pezzi Piercarlo Citterio Roberto Verardi Krzysztof Urbaniec 《Journal of Cleaner Production》2005,13(15):1447-1460
In the past years we evaluated different strategies with the aim of eliminating completely from the beet sugar factory, the traditional calco-carbonic purification process taking into account the well-known problems related to the utilization of lime and the production of carbonation sludge.To complete the picture of the possible solutions to be adopted for the elimination of the traditional purification process, we tested and evaluated in laboratory and in pilot plants a new eco-friendly proposal.The results obtained, as well as the proposed flow-sheet and some economic evaluations, are presented and discussed. 相似文献
68.
69.
Study on the toxicity of binary equitoxic mixtures of metals using the luminescent bacteria Vibrio fischeri as a biological target 总被引:3,自引:0,他引:3
Results from two mathematical approaches to predict the toxicity of all the possible binary equitoxic mixtures of Co, Cd, Cu, Zn and Pb were compared to the observed toxicity of these mixtures to Vibrio fischeri bacteria. Combined effect of the metals was found to be antagonistic for Co-Cd, Cd-Zn, Cd-Pb and Cu-Pb, synergistic for Co-Cu and Zn-Pb and merely additive in other cases, revealing a complex pattern of possible interactions. Besides, Cd appears much less toxic to the bacterial model than to animal cells. The synergistic effect of the Co-Cu combination and the strong lowering of Pb toxicity in the presence of Cd deserve much attention when establishing environmental safety regulations. 相似文献
70.
Electrophoretic variation in proteins encoded by 23 loci revealed substantial genetic differentiation among populations of bicolor damselfish (Eupomacentrus partitus) collected from four coral reefs in the Florida Keys, USA, during 1986–1988. Genetic differentiation was concentrated between a sample collected from Little Grecian Rocks Reef (LGR) and the remaining samples, including fish from a reef only 600 m distant (Grecian Rocks Reef). Genetic distinction of the LGR sample derived from significantly heterogenous allelic frequencies at six of eight polymorphic loci. Aco-1 (aconitase); Ada (adenosine deaminase); Gpi-2 (glucosephosphate isomerase); Ldh-2 and Ldh-3 (lactate dehydrogenase); and Me-1 (malic enzyme); nevertheless, differentiation at cytosolic aconitase (Aco-1) far exceeded that observed for other loci (fixation index, F
ST=0.482), and differences in Aco-1 allele frequencies were largely responsible for large genetic distances (0.20) between LGR and the other reefs. Paradoxically, estimates of numbers of migrants exchanged between reefs per generation (mN
e=17.47) indicated the potential for extensive gene flow. The extent of genetic differentiation among these populations is evaluated relative to models of population genetic structure based on equilibrium between gene flow and natural selection or genetic drift. 相似文献