全文获取类型
收费全文 | 899篇 |
免费 | 3篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 38篇 |
废物处理 | 22篇 |
环保管理 | 269篇 |
综合类 | 68篇 |
基础理论 | 174篇 |
污染及防治 | 257篇 |
评价与监测 | 57篇 |
社会与环境 | 19篇 |
灾害及防治 | 4篇 |
出版年
2022年 | 7篇 |
2021年 | 5篇 |
2020年 | 8篇 |
2018年 | 8篇 |
2017年 | 8篇 |
2016年 | 17篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 114篇 |
2012年 | 21篇 |
2011年 | 43篇 |
2010年 | 32篇 |
2009年 | 27篇 |
2008年 | 46篇 |
2007年 | 41篇 |
2006年 | 47篇 |
2005年 | 27篇 |
2004年 | 39篇 |
2003年 | 32篇 |
2002年 | 31篇 |
2001年 | 22篇 |
2000年 | 17篇 |
1999年 | 8篇 |
1998年 | 15篇 |
1997年 | 14篇 |
1996年 | 16篇 |
1995年 | 12篇 |
1994年 | 11篇 |
1993年 | 9篇 |
1992年 | 13篇 |
1991年 | 14篇 |
1990年 | 5篇 |
1989年 | 13篇 |
1988年 | 8篇 |
1987年 | 11篇 |
1986年 | 8篇 |
1985年 | 10篇 |
1984年 | 19篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 13篇 |
1980年 | 5篇 |
1979年 | 14篇 |
1978年 | 8篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1972年 | 5篇 |
1971年 | 4篇 |
1970年 | 5篇 |
排序方式: 共有908条查询结果,搜索用时 15 毫秒
211.
212.
213.
E.?P.?BadásEmail author J.?Martínez J.?Rivero-de Aguilar C.?Ponce M.?Stevens S.?Merino 《Die Naturwissenschaften》2018,105(1-2):17
Carry-over effects refer to processes that occur in one season and influence fitness in the following. In birds, two costly activities, namely reproduction and moult, are restricted to a small time window, and sometimes overlap. Thus, colour in newly moulted feathers is likely to be affected by the costs of reproduction. Using models of bird vision we investigated male colour change in a free-living population of blue tits (Cyanistes caeruleus) in three sampling occasions: spring 1, winter and spring 2. We related crown, tail, breast and cheek feather colouration after the moult (winter) to the intensity of infections by blood parasites during reproduction (spring 1). In the following spring (spring 2), we explored mating patterns with respect to changes in feather colour (springs 1 vs. 2). Males that were less intensely infected by the malaria parasite Plasmodium while breeding showed purer white cheek feathers in winter, which may indicate higher feather quality. Increased brightness in the white cheek was associated with better body condition during reproduction. In the following season, males with brighter cheeks paired with females that had noticeably brighter cheek patches compared to the male’s previous mate. These results suggest that the conditions experienced during reproduction are likely to affect moult and thus feather colouration, at least in the white patch. High quality individuals may allocate resources efficiently during reproduction increasing future reproductive success through variation in mating patterns. Carry-over effects from reproduction might extend not only to the non-breeding phase, but also to the following breeding season. 相似文献
214.
Yus Donald Chaniago Jae-Kyeong Kim Myung-Jun Park Kee-Kahb Koo Moonyong Lee 《Journal of Material Cycles and Waste Management》2016,18(2):366-376
Currently, waste photoresist stripper from the semiconductor industries is generally incinerated at high temperatures or processed as a high-calorie fuel, which can have adverse effects on the environment and economy. Recovery of valuable solvents from waste photoresist strippers is, therefore, very important for thin flat transistor-liquid crystal display (TFT-LCD) manufactures to reduce the production costs and protect the environment against industrial waste. In the present work, systematic laboratory-scale distillation experiments were carried out to regenerate the organic solvents from the waste photoresist stripper and determine if they are feasible to recycle for commercial TFT-LCD grade chemicals: in particular, 1-hydroxyethylpiperazine and methyl diglycol were mainly tried to retrieve. Based on the experiment results, possible alternative distillation sequences were examined through intensive techno-economic analysis using a rigorous process simulator. As a result, an optimal distillation sequence and condition were drawn to separate valuable organic solvents from waste photoresist stripper for a commercial purpose recovery process. 相似文献
215.
Ralph I. Larsen William F. McDonnell Donald H. Horstman Lawrence J. Folinsbee 《Journal of the Air & Waste Management Association (1995)》2013,63(4):455-459
Forced expiratory volume in 1 second (FEV1) was measured in 21 men exercising while exposed to four O3 concentrations (0.0,0.08,0.10, and 0.12 ppm). A lognormal multiple linear regression model was fitted to their mean FEV1 measurements to predict FEV1 percent decrease as a function of O3 concentration and exposure duration. The exercise level used was probably comparable to heavy manual labor. The longest O3, exposure studied was 6 h. Extrapolating cautiously to an 8-h workday of heavy manual labor, the model predicts that O3 concentrations of 0.08, 0.10, and 0.12 ppm would decrease FEV1 by 9,15, and 20 percent, respectively. 相似文献
216.
217.
Matthias Schmid Torsten Hothorn Kelly O. Maloney Donald E. Weller Sergej Potapov 《Environmental and Ecological Statistics》2011,18(4):709-733
Indices of biotic integrity have become an established tool to quantify the condition of small non-tidal streams and their
watersheds. To investigate the effects of watershed characteristics on stream biological condition, we present a new technique
for regressing IBIs on watershed-specific explanatory variables. Since IBIs are typically evaluated on an ordinal scale, our
method is based on the proportional odds model for ordinal outcomes. To avoid overfitting, we do not use classical maximum
likelihood estimation but a component-wise functional gradient boosting approach. Because component-wise gradient boosting
has an intrinsic mechanism for variable selection and model choice, determinants of biotic integrity can be identified. In
addition, the method offers a relatively simple way to account for spatial correlation in ecological data. An analysis of
the Maryland Biological Streams Survey shows that nonlinear effects of predictor variables on stream condition can be quantified
while, in addition, accurate predictions of biological condition at unsurveyed locations are obtained. 相似文献
218.
S. C. Faulkner M. C. A. Stevens S. S. Romañach P. A. Lindsey S. C. Le Comber 《Conservation biology》2018,32(3):685-693
Poaching can have devastating impacts on animal and plant numbers, and in many countries has reached crisis levels, with illegal hunters employing increasingly sophisticated techniques. We used data from an 8‐year study in Savé Valley Conservancy, Zimbabwe, to show how geographic profiling—a mathematical technique originally developed in criminology and recently applied to animal foraging and epidemiology—can be adapted for use in investigations of wildlife crime. The data set contained information on over 10,000 incidents of illegal hunting and the deaths of 6,454 wild animals. We used a subset of data for which the illegal hunters’ identities were known. Our model identified the illegal hunters’ home villages based on the spatial locations of the hunting incidences (e.g., snares). Identification of the villages was improved by manipulating the probability surface inside the conservancy to reflect the fact that although the illegal hunters mostly live outside the conservancy, the majority of hunting occurs inside the conservancy (in criminology terms, commuter crime). These results combined with rigorous simulations showed for the first time how geographic profiling can be combined with GIS data and applied to situations with more complex spatial patterns, for example, where landscape heterogeneity means some parts of the study area are less likely to be used (e.g., aquatic areas for terrestrial animals) or where landscape permeability differs (e.g., forest bats tend not to fly over open areas). More broadly, these results show how geographic profiling can be used to target antipoaching interventions more effectively and more efficiently and to develop management strategies and conservation plans in a range of conservation scenarios. 相似文献
219.
220.