全文获取类型
收费全文 | 394篇 |
免费 | 4篇 |
国内免费 | 8篇 |
专业分类
安全科学 | 12篇 |
废物处理 | 18篇 |
环保管理 | 31篇 |
综合类 | 61篇 |
基础理论 | 99篇 |
环境理论 | 4篇 |
污染及防治 | 119篇 |
评价与监测 | 21篇 |
社会与环境 | 38篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 5篇 |
2022年 | 10篇 |
2021年 | 7篇 |
2020年 | 10篇 |
2019年 | 19篇 |
2018年 | 15篇 |
2017年 | 20篇 |
2016年 | 26篇 |
2015年 | 10篇 |
2014年 | 23篇 |
2013年 | 21篇 |
2012年 | 24篇 |
2011年 | 24篇 |
2010年 | 26篇 |
2009年 | 19篇 |
2008年 | 18篇 |
2007年 | 32篇 |
2006年 | 9篇 |
2005年 | 12篇 |
2004年 | 6篇 |
2003年 | 14篇 |
2002年 | 17篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1990年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1964年 | 1篇 |
1962年 | 1篇 |
1956年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有406条查询结果,搜索用时 15 毫秒
31.
Francesca Pilotto Jonathan D. Tonkin Kathrin Januschke Armin W. Lorenz Jonas Jourdan Andrea Sundermann Daniel Hering Stefan Stoll Peter Haase 《Conservation biology》2019,33(1):132-141
Although experiences with ecological restoration continue to accumulate, the effectiveness of restoration for biota remains debated. We complemented a traditional taxonomic analysis approach with information on 56 species traits to uncover the responses of 3 aquatic (fish, macroinvertebrates, macrophytes) and 2 terrestrial (carabid beetles, floodplain vegetation) biotic groups to 43 hydromorphological river restoration projects in Germany. All taxonomic groups responded positively to restoration, as shown by increased taxonomic richness (10–164%) and trait diversity (habitat, dispersal and mobility, size, form, life history, and feeding groups) (15–120%). Responses, however, were stronger for terrestrial than aquatic biota, and, contrary to our expectation, taxonomic responses were stronger than those of traits. Nevertheless, trait analysis provided mechanistic insights into the drivers of community change following restoration. Trait analysis for terrestrial biota indicated restoration success was likely enhanced by lateral connectivity and reestablishment of dynamic processes in the floodplain. The weaker response of aquatic biota suggests recovery was hindered by the persistence of stressors in the aquatic environment, such as degraded water quality, dispersal constraints, and insufficient hydromorphological change. Therefore, river restoration requires combined local- and regional-scale approaches to maximize the response of both aquatic and terrestrial organisms. Due to the contrasting responses of aquatic and terrestrial biota, the planning and assessment of river restoration outcomes should consider effects on both components of riverine landscapes. 相似文献
32.
33.
34.
Summary In four fruit-eating bats sniff-rate analysis revealed the threshold value for natural banana odour to be 1 × 10–4 vol% of head-space while the threshold values for its major components were found to be 3–6 orders of magnitude higher; even the total of molecules present at the threshold dilution of banana odour was 2 orders of magnitude below the lowest threshold values obtained for single components. Thus, the responsiveness of the bats to threshold concentration of natural banana odour is discussed as an example of synergism of stimuli. 相似文献
35.
In butterflies and other insects, fecundity generally increases with female adult weight. Hence, most butterflies are essentially "capital breeders", because nutrients acquired during the larval stage are stored and subsequently used for egg production during the adult stage. However, in some species, males transfer a large nutritious ejaculate to the female at mating. These females can partly be characterized as "income breeders", and female mass can potentially be decoupled from fecundity to some extent. In the gift-giving green-veined white butterfly Pieris napi, it has been shown that female fecundity and longevity increase with number of matings and also that females mature at smaller size under poor food conditions compared to males. So it has been suggested that females can compensate for their smaller size through nuptial feeding. Here we test this hypothesis in P. napi by assessing female fecundity and longevity in relation to female mass and polyandry. The results showed no support for the hypothesis. Smaller females were not capable of increasing their mating rate to compensate for a low weight at eclosion. Instead, larger females remated sooner. Also, smaller females suffered from both a reduced daily and total fecundity compared to larger females and this decrease in fecundity was independent of female mating status, i.e. females allowed to mate only once and multiply mated females suffered to the same extent from their smaller size. 相似文献
36.
Pelagic snake pipefish, Entelurus aequoreus (Linnaeus, 1758), occurred regularly in plankton catches that were conducted in areas off the shelf during the German 2004
mackerel and horse mackerel egg survey. Out of a total of 196 plankton hauls 57 tows yielded 112 specimens of adult snake
pipefish with a total length between 15.0 and 35.2 cm. A proportion of 56.3% were egg-carrying males. Also seven recently
released juveniles were caught indicating that off shore reproduction in this species starts much earlier than in the inshore
habitat. 相似文献
37.
38.
Newly mated queens of monogynous (single queen) ants usually found their colonies independently, without the assistance of workers. In polygynous (multiple queen) species queens are often adopted back into their natal nest and new colonies are established by budding. We report that the Australian 'living-fossil' ant, Nothomyrmecia macrops, is exceptional in that its single queen can be replaced by one of the colony's daughters. This type of colony founding is an interesting alternative reproductive strategy in monogynous ants, which maximizes fitness under kin selection. Successive queen replacement results in a series of reproductives over time (serial polygyny), making these colonies potentially immortal. Workers raise nieces and nephews (relatedness h 0.375) the year after queen replacement. Although N. macrops is 'primitive' in many other respects, colony inheritance is likely to be a derived specialization resulting from ecological constraints on solitary founding. 相似文献
39.
Assessing the microbial activity of soil samples,its nutrient limitation and toxic effects of contaminants using a simple respiration test 总被引:4,自引:0,他引:4
Eight soil samples from five wells of a former gas plant site differing in the contamination with BTEX and PAHs as well as the nutrient content were investigated by soil respiration measurements. The basal, glucose as well as NH4+ and PO4(3-) induced cumulative oxygen consumption and carbon dioxide production in 72 and 120 h were determined and additionally the maximal turnover rates and the limitation quotients were calculated. Without additional carbon source only one of five investigated samples was clearly nutrient limited. After glucose supplementation four of seven investigated samples showed nutrient limitation that was in accordance with the available ammonium and phosphorous content. BTEX and PAHs did not exhibit an inhibiting effect on the respiration rate. In contrast, BTEX containing samples exhibited the highest oxygen consumption indicating biodegradation of the contaminants. The results show that oxygen consumption and carbon dioxide production as well as the kinetic of these processes are all informative parameters characterizing the whole microbial respiration potential and their nutrient limitation in soil samples. Therefore this fast respirometric method can be used for the decision if further detailed studies of the bioremediation are useful and if nutrient supplementation is recommended to enhance natural attenuation. 相似文献
40.
Skotnica J Gilbert M Weingart I Wilhelm C 《Environmental pollution (Barking, Essex : 1987)》2003,123(1):15-20
The effect of ozone (6 h, various concentrations from 0 to 350 ppb) on barley (Hordeum vulgare L., cv. Bomi) and tomato (Lycopersicon esculentum L., cv. Yellow Cherry) leaves was investigated in parallel by thermoluminescence (TL) and fluorescence (FL) methods. Several significant changes were found in TL glow curves measured after excitation by one single turnover flash at +2 degree C in the temperature range from 2 to 170 degree C immediately after ozone exposure. Contrary to TL, ozone induced only negligible changes in FL parameters F0, FM and Fv/FM. Measurements done 24 h after ozone exposure showed partial recovery of ozone-induced changes. The extent of recovery was not the same in different parts of TL curves. Fluorescence parameters were not significantly changed. The results demonstrate that TL parameters are more sensitive to ozone than conventially used FL parameters F0, FM and Fv/FM. Moreover, TL measurements seem to give information not only about the PSII electron transport, but also about the extent of oxidative damage and membrane lipid peroxidation. It is concluded, that TL can be a highly informative tool for monitoring the impact of ozone on plants. 相似文献