全文获取类型
| 收费全文 | 11892篇 |
| 免费 | 111篇 |
| 国内免费 | 88篇 |
专业分类
| 安全科学 | 336篇 |
| 废物处理 | 442篇 |
| 环保管理 | 1638篇 |
| 综合类 | 2121篇 |
| 基础理论 | 3134篇 |
| 环境理论 | 7篇 |
| 污染及防治 | 2969篇 |
| 评价与监测 | 735篇 |
| 社会与环境 | 624篇 |
| 灾害及防治 | 85篇 |
出版年
| 2022年 | 104篇 |
| 2021年 | 98篇 |
| 2020年 | 80篇 |
| 2019年 | 93篇 |
| 2018年 | 163篇 |
| 2017年 | 142篇 |
| 2016年 | 222篇 |
| 2015年 | 194篇 |
| 2014年 | 268篇 |
| 2013年 | 880篇 |
| 2012年 | 356篇 |
| 2011年 | 497篇 |
| 2010年 | 409篇 |
| 2009年 | 478篇 |
| 2008年 | 521篇 |
| 2007年 | 518篇 |
| 2006年 | 453篇 |
| 2005年 | 420篇 |
| 2004年 | 352篇 |
| 2003年 | 365篇 |
| 2002年 | 351篇 |
| 2001年 | 472篇 |
| 2000年 | 346篇 |
| 1999年 | 209篇 |
| 1998年 | 131篇 |
| 1997年 | 157篇 |
| 1996年 | 163篇 |
| 1995年 | 190篇 |
| 1994年 | 192篇 |
| 1993年 | 159篇 |
| 1992年 | 132篇 |
| 1991年 | 169篇 |
| 1990年 | 163篇 |
| 1989年 | 157篇 |
| 1988年 | 115篇 |
| 1987年 | 114篇 |
| 1986年 | 118篇 |
| 1985年 | 91篇 |
| 1984年 | 108篇 |
| 1983年 | 110篇 |
| 1982年 | 118篇 |
| 1981年 | 108篇 |
| 1980年 | 96篇 |
| 1979年 | 112篇 |
| 1978年 | 73篇 |
| 1977年 | 76篇 |
| 1975年 | 76篇 |
| 1973年 | 72篇 |
| 1972年 | 65篇 |
| 1967年 | 66篇 |
排序方式： 共有10000条查询结果，搜索用时 0 毫秒
81.
82.
Steven R. Beissinger Jason G. Bragg David J. Coates J. Gerard B. Oostermeijer Paul Sunnucks Nathan H. Schumaker Meredith V. Trotter Andrew G. Young 《Conservation biology》2015,29(3):755-764
We examined how ecological and evolutionary (eco‐evo) processes in population dynamics could be better integrated into population viability analysis (PVA). Complementary advances in computation and population genomics can be combined into an eco‐evo PVA to offer powerful new approaches to understand the influence of evolutionary processes on population persistence. We developed the mechanistic basis of an eco‐evo PVA using individual‐based models with individual‐level genotype tracking and dynamic genotype–phenotype mapping to model emergent population‐level effects, such as local adaptation and genetic rescue. We then outline how genomics can allow or improve parameter estimation for PVA models by providing genotypic information at large numbers of loci for neutral and functional genome regions. As climate change and other threatening processes increase in rate and scale, eco‐evo PVAs will become essential research tools to evaluate the effects of adaptive potential, evolutionary rescue, and locally adapted traits on persistence. 相似文献
83.
Adrienne B. Nicotra Erik A. Beever Amanda L. Robertson Gretchen E. Hofmann John O'Leary 《Conservation biology》2015,29(5):1268-1278
Natural‐resource managers and other conservation practitioners are under unprecedented pressure to categorize and quantify the vulnerability of natural systems based on assessment of the exposure, sensitivity, and adaptive capacity of species to climate change. Despite the urgent need for these assessments, neither the theoretical basis of adaptive capacity nor the practical issues underlying its quantification has been articulated in a manner that is directly applicable to natural‐resource management. Both are critical for researchers, managers, and other conservation practitioners to develop reliable strategies for assessing adaptive capacity. Drawing from principles of classical and contemporary research and examples from terrestrial, marine, plant, and animal systems, we examined broadly the theory behind the concept of adaptive capacity. We then considered how interdisciplinary, trait‐ and triage‐based approaches encompassing the oft‐overlooked interactions among components of adaptive capacity can be used to identify species and populations likely to have higher (or lower) adaptive capacity. We identified the challenges and value of such endeavors and argue for a concerted interdisciplinary research approach that combines ecology, ecological genetics, and eco‐physiology to reflect the interacting components of adaptive capacity. We aimed to provide a basis for constructive discussion between natural‐resource managers and researchers, discussions urgently needed to identify research directions that will deliver answers to real‐world questions facing resource managers, other conservation practitioners, and policy makers. Directing research to both seek general patterns and identify ways to facilitate adaptive capacity of key species and populations within species, will enable conservation ecologists and resource managers to maximize returns on research and management investment and arrive at novel and dynamic management and policy decisions. 相似文献
84.
One of the main goals of conservation biology is to understand the factors shaping variation in biodiversity across the planet. This understanding is critical for conservation planners to be able to develop effective conservation strategies. Although many studies have focused on species richness and the protection of rare and endemic species, less attention has been paid to the protection of the phylogenetic dimension of biodiversity. We explored how phylogenetic diversity, species richness, and phylogenetic community structure vary in seed plant communities along an elevational gradient in a relatively understudied high mountain region, the Dulong Valley, in southeastern Tibet, China. As expected, phylogenetic diversity was well correlated with species richness among the elevational bands and among communities. At the community level, evergreen broad‐leaved forests had the highest levels of species richness and phylogenetic diversity. Using null model analyses, we found evidence of nonrandom phylogenetic structure across the region. Evergreen broad‐leaved forests were phylogenetically overdispersed, whereas other vegetation types tended to be phylogenetically clustered. We suggest that communities with high species richness or overdispersed phylogenetic structure should be a focus for biodiversity conservation within the Dulong Valley because these areas may help maximize the potential of this flora to respond to future global change. In biodiversity hotspots worldwide, we suggest that the phylogenetic structure of a community may serve as a useful measure of phylogenetic diversity in the context of conservation planning. 相似文献
85.
Rosaleen Duffy Freya A. V. St John Bram Büscher Dan Brockington 《Conservation biology》2016,30(1):14-22
Conservation organizations have increasingly raised concerns about escalating rates of illegal hunting and trade in wildlife. Previous studies have concluded that people hunt illegally because they are financially poor or lack alternative livelihood strategies. However, there has been little attempt to develop a richer understanding of the motivations behind contemporary illegal wildlife hunting. As a first step, we reviewed the academic and policy literatures on poaching and illegal wildlife use and considered the meanings of poverty and the relative importance of structure and individual agency. We placed motivations for illegal wildlife hunting within the context of the complex history of how wildlife laws were initially designed and enforced to indicate how hunting practices by specific communities were criminalized. We also considered the nature of poverty and the reasons for economic deprivation in particular communities to indicate how particular understandings of poverty as material deprivation ultimately shape approaches to illegal wildlife hunting. We found there is a need for a much better understanding of what poverty is and what motivates people to hunt illegally. 相似文献
86.
87.
88.
Georgia Mavrommati Kostas Bithas Mark E. Borsuk Richard B. Howarth 《Conservation biology》2016,30(6):1173-1181
In the Anthropocene, coupled human and natural systems dominate and only a few natural systems remain relatively unaffected by human influence. On the one hand, conservation criteria based on areas of minimal human impact are not relevant to much of the biosphere. On the other hand, conservation criteria based on economic factors are problematic with respect to their ability to arrive at operational indicators of well‐being that can be applied in practice over multiple generations. Coupled human and natural systems are subject to economic development which, under current management structures, tends to affect natural systems and cross planetary boundaries. Hence, designing and applying conservation criteria applicable in real‐world systems where human and natural systems need to interact and sustainably coexist is essential. By recognizing the criticality of satisfying basic needs as well as the great uncertainty over the needs and preferences of future generations, we sought to incorporate conservation criteria based on minimal human impact into economic evaluation. These criteria require the conservation of environmental conditions such that the opportunity for intergenerational welfare optimization is maintained. Toward this end, we propose the integration of ecological–biological thresholds into decision making and use as an example the planetary‐boundaries approach. Both conservation scientists and economists must be involved in defining operational ecological–biological thresholds that can be incorporated into economic thinking and reflect the objectives of conservation, sustainability, and intergenerational welfare optimization. 相似文献
89.
90.
重金属在牡蛎(Crassostrea virginica)中的生物积累及其影响因素的研究 总被引：11，自引：0，他引：11
牡蛎软体，贝壳和沉积物中Ｃｄ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｎ、Ｐｂ和Ｚｎ等重金属元素被同步分析研究，研究结果表明，重金属在牡蛎中的生物积累是牡自身的新陈代谢、重金属元素的地球化学性质和环境诸因素综合影响的结果，其中牡蛎斩生理作用对重金属在软体中的积累产生的影响尤为重要，而贝壳中重金属的积累对来自环境的影响更为敏感。 相似文献