全文获取类型
收费全文 | 969篇 |
免费 | 11篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 18篇 |
废物处理 | 61篇 |
环保管理 | 55篇 |
综合类 | 182篇 |
基础理论 | 161篇 |
污染及防治 | 334篇 |
评价与监测 | 109篇 |
社会与环境 | 60篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 14篇 |
2022年 | 36篇 |
2021年 | 43篇 |
2020年 | 18篇 |
2019年 | 18篇 |
2018年 | 51篇 |
2017年 | 34篇 |
2016年 | 60篇 |
2015年 | 49篇 |
2014年 | 52篇 |
2013年 | 80篇 |
2012年 | 39篇 |
2011年 | 67篇 |
2010年 | 51篇 |
2009年 | 27篇 |
2008年 | 65篇 |
2007年 | 53篇 |
2006年 | 44篇 |
2005年 | 30篇 |
2004年 | 23篇 |
2003年 | 27篇 |
2002年 | 23篇 |
2001年 | 18篇 |
2000年 | 12篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1990年 | 3篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1964年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有986条查询结果,搜索用时 15 毫秒
211.
Kristen J. Navara Geoffrey E. Hill Mary T. Mendonça 《Behavioral ecology and sociobiology》2006,60(3):392-398
The deposition of androgens into the yolks of eggs can have long-lasting effects on the growth and development of young birds. It has been proposed that female birds and reptiles deposit yolk androgens according to the differential allocation hypothesis (DAH), which posits the allocation of more resources to offspring sired by more attractive, higher-quality males. We examined deposition patterns of yolk androgens in relation to mate attractiveness in the house finch Carpodacus mexicanus. Contrary to the predictions of the DAH, female house finches deposited significantly more androgens into eggs sired by less attractive males. We propose that, rather than serving as resources, androgens are used as mediators in a compensatory distribution strategy, enabling females to improve the quality of young produced with less attractive males. 相似文献
212.
Jonathan Mark Wilson Alexandre Leitão Ana Filipa Gonçalves Catarina Ferreira Patrick Reis-Santos Ana-Violeta Fonseca Joana Moreira da Silva José Carlos Antunes Cristina Pereira-Wilson João Coimbra 《Marine Biology》2007,151(5):1633-1645
The Anguillid juvenile glass eel must deal with the osmoregulatory consequences of highly variable environmental salinities
on its recruitment migration from coastal to fresh waters. Changes in ionoregulatory parameters and branchial ion transport
protein [Na+/K+-ATPase, Na+:K+:2Cl− cotransporter (NKCC), cystic fibrosis transmembrane regulator (CFTR) anion channel, V-type proton ATPase] expression (activities,
protein and/or mRNA level expression and/or cellular localization) in response to acclimation to a broad range of ionic strengths
[distilled water (DW) to hypersaline water (HSW; 150%) sea water (SW 32‰)] was studied. The estuarine glass eels were very
euryhaline and successfully acclimated to acute changes in environmental ionic strength from 50% SW, with high mortality only
observed in HSW (51%) and sublethal osmoregulatory indicators (whole body water content and sodium levels) disturbed at the
extremes (DW and HSW). Central to a high salinity acclimation were elevated branchial Na+/K+-ATPase, NKCC and CFTR expression. At lower salinity, Na+/K+-ATPase expression was maintained and NKCC and CFTR expressions were reduced. Branchial chloride cells increased in size up
to SW but decreased in HSW. During hypotonic disturbance (DW), no compensatory elevation in V-ATPase or Na+/K+-ATPase expression was observed. 相似文献
213.
Rhithropanopeus harrisii (Gould) is an introduced species in the estuary of the Mondego River (Portugal): it was first recorded from the Iberian Peninsula in 1989. The larval development of this population was studied under laboratory conditions at different temperatures and salinities, and showed a larval development pattern very similar to that reported for American estuarine populations of this species. Larval development was negatively correlated with temperature. Time to megalopa varied between 7 and 35 d; the first crab (C1) was reached after a maximum of 11 to 43 d. Larval development was optimum at 25°C and 15S. Larval survival was maximum at 10, 15 and 20S at all three temperatures studied (20, 25 and 30°C). The percentage of abnormal megalopae increased with increasing salinity to a maximum (100%) at 30S; incidence of abnormality was not affected by temperature. 相似文献
214.
A twin pregnancy with trisomy 10 p due to a paternal 10;12 translocation is reported. The prenatal diagnosis steps followed in twin pregnancies are reviewed and the concordant features of trisomy 10 p seen in both fetuses confirm previous reports on the clinical features of this chromosomal defect. 相似文献
215.
Juliano Gonçalves Pereira Vanessa Mendonça Soares Fernanda Gil de Souza Leonardo Ereno Tadielo Emanoelli Aparecida Rodrigues dos Santos Mário Celso Sperotto Brum Andreia Henzel Eduarda Hallal Duval Fernando Rosado Spilki Wladimir Padilha da Silva 《Food and environmental virology》2018,10(4):365-372
The aim of this study was to investigate hepatitis A virus (HAV), hepatitis E (HEV), and rotavirus (RV) in fresh and processed meat traded on the border of Brazil with Argentina and Uruguay. In total, 159 samples of raw and processed foods of animal origin were collected in Paso de los Libres, Argentina (n?=?53 raw meat, n?=?24 processed meat) and Rivera, Uruguay (n?=?55 raw meat, n?=?18 processed meat), or were seized by the Brazilian International Agricultural Surveillance System—VIGIAGRO (Brazil–Argentina border) (n?=?8 raw meat, n?=?1 bush meat). All samples were tested for the presence of HAV, HEV, and RV genomes. HAV genes were detected in 18.23% of samples and RV genes in 23.89%. No HEV-positive samples were detected. HAV was also detected in two of the VIGIAGRO samples. Processed meats from Argentina and Uruguay had a higher rate of HAV and RV than raw meat (P?>?0.05). The median HAV in the Argentinian and Uruguayan samples was 6.9?×?104 and 3.5?×?103 copies/g, respectively. The presence of RV viral genes in raw meats from Argentina was significant, and this was not observed in processed meats. The presence of HAV and RV genes in a significant portion of products from Argentina and Uruguay is a potential source of human infection. This also indicates precarious conditions of acquisition, processing, and manipulation, which could be improved by improved regulation of food across borders. 相似文献
216.
217.
Fatma Krichen Wafa Karaoud Nadhem Sayari Assaâd Sila Fatma Kallel Semia Ellouz-Chaabouni Ali Bougatef 《Journal of Polymers and the Environment》2016,24(2):166-175
Sulfated polysaccharides were isolated from two Tunisian fish skins grey triggerfish (Balistes capriscus) (GTSP) and smooth hound (Mustelus mustelus) (SHSP). Their chemical and physical characteristics were investigated. The Analysis of surface morphology by scanning electron microscopy of both sulfated polysaccharides displayed the same shape with netted structure. The antioxidant activities of GTSP and SHSP were evaluated using various in vitro antioxidant assays: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, reducing power, β-carotene bleaching inhibition assay (IC50 GTSP = 0.5 mg mL?1 and IC50 SHSP = 0.6 mg mL?1) and DNA nicking assay. Both sulfated polysaccharides exhibited good antioxidant activities. The sulfated polysaccharides showed strong angiotensin I-converting enzyme inhibitory activities (IC50 GTSP = 0.16 mg mL?1 and IC50 SHSP = 0.18 mg mL?1). These results revealed that GTSP and SHSP exhibited significant antihypertensive activities. Overall, the results indicated that grey triggerfish and smooth hound skins can be used to generate high value-added products, thus offering a valuable source of bioactive sulfated polysaccharides for application in wide range of biotechnological applications. 相似文献
218.
Takayuki Miura Sébastien Lhomme Jean-Claude Le Saux Philippe Le Mehaute Yvonnick Guillois Elizabeth Couturier Jacques Izopet Florence Abranavel Françoise S. Le Guyader 《Food and environmental virology》2016,8(3):194-199
A hepatitis E outbreak, which occurred on a small isolated island, provided an opportunity to evaluate the association between the number of hepatitis E cases in the community and the concentration of virus detected in sewage. Samples were collected from the different sewage treatment plants from the island and analyzed for the presence of hepatitis E (HEV) virus using real-time RT-PCR. We demonstrated that if 1–4 % of inhabitants connected to a WWTP were infected with HEV, raw sewage contained HEV at detectable levels. The finding that such a small number of infected people can contaminate municipal sewage works raises the potential of the further distribution of the virus. Indeed, investigating the routes of transmission of HEV, including the potential for sewage effluent to contain infectious HEV, may help us to better understand the epidemiology of this pathogen, which is considered to be an emerging concern in Europe. 相似文献
219.
220.
Population viability analysis (PVA) is widely used to assess population‐level impacts of environmental changes on species. When combined with sensitivity analysis, PVA yields insights into the effects of parameter and model structure uncertainty. This helps researchers prioritize efforts for further data collection so that model improvements are efficient and helps managers prioritize conservation and management actions. Usually, sensitivity is analyzed by varying one input parameter at a time and observing the influence that variation has over model outcomes. This approach does not account for interactions among parameters. Global sensitivity analysis (GSA) overcomes this limitation by varying several model inputs simultaneously. Then, regression techniques allow measuring the importance of input‐parameter uncertainties. In many conservation applications, the goal of demographic modeling is to assess how different scenarios of impact or management cause changes in a population. This is challenging because the uncertainty of input‐parameter values can be confounded with the effect of impacts and management actions. We developed a GSA method that separates model outcome uncertainty resulting from parameter uncertainty from that resulting from projected ecological impacts or simulated management actions, effectively separating the 2 main questions that sensitivity analysis asks. We applied this method to assess the effects of predicted sea‐level rise on Snowy Plover (Charadrius nivosus). A relatively small number of replicate models (approximately 100) resulted in consistent measures of variable importance when not trying to separate the effects of ecological impacts from parameter uncertainty. However, many more replicate models (approximately 500) were required to separate these effects. These differences are important to consider when using demographic models to estimate ecological impacts of management actions. 相似文献