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801.
Silvia Ceauşu Rose A. Graves Alexander K. Killion Jens-Christian Svenning Neil H. Carter 《Conservation biology》2019,33(3):543-553
Sustaining wildlife populations, which provide both ecosystem services and disservices, represents a worldwide conservation challenge. The ecosystem services and Ostrom's social–ecological systems frameworks have been adopted across natural and social sciences to characterize benefits from nature. Despite their generalizability, individually they do not include explicit tools for addressing the sustainable management of many wildlife populations. For instance, Ostrom's framework does not specifically address competing perspectives on wildlife, whereas the ecosystem services framework provides a limited representation of the social and governance context wherein such competing perspectives are embedded. We developed a unified social–ecological framework of ecosystem disservices and services (SEEDS) that advances both frameworks by explicitly acknowledging the importance of competing wildlife perspectives embedded in the social and governance contexts. The SEEDS framework emulates the hierarchical structure of Ostrom's social–ecological systems, but adds subsystems reflecting heterogeneous stakeholder views and experiences of wildlife-based services and disservices. To facilitate operationalizing SEEDS and further broader analyses across human–wildlife systems, we devised a list of variables to describe SEEDS subsystems, such as types and level of services and disservices, cost and benefit sharing, and social participation of stakeholders. Steps to implement SEEDS involve engaging local communities and stakeholders to define the subsystems, analyze interactions and outcomes, and identify leverage points and actions to remedy unwanted outcomes. These steps connect SEEDS with other existing approaches in social–ecological research and can guide analyses across systems or within individual systems to provide new insights and management options for sustainable human–wildlife coexistence. 相似文献
802.
Authentic leadership has received considerable attention and research support over the past decade. Now the time has come to refine and better understand how it impacts performance. This study investigates the moderating role followers' positive psychological capital (PsyCap) and the mediating role that leader–member exchange (LMX) may play in influencing the relationship between authentic leadership and followers' performance. Specifically, we tested this mediated moderation model with matched data from 794 followers and their immediate leaders. We found that authentic leadership is positively related to LMX and consequently followers' performance, and to a larger degree, among followers who have low rather than high levels of PsyCap. Our discussion highlights the benefits of understanding the roles of relational processes and followers' positive psychological resources involved in the effectiveness of authentic leadership and how they can be practically implemented. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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804.
通过测定上海市售动物性食品中PCBs的浓度和生物有效性,评估该地区PCBs的人体日暴露量.结果表明,不同种类食品中PCBs的浓度在未检出~3734.3pg/g(湿重)之间,3~6氯PCBs为主要同系物.鱼类中PCBs浓度高于畜类、禽类和软体类.鱼类PCBs的浓度水平遵循以下两规律:海水鱼>淡水鱼;肉食性鱼>杂食性鱼>草食性鱼.采用模拟人体胃肠消化过程测得PCBs的生物有效性,由于食品中脂肪含量与PCBs的生物有效性具有显著的线性关系,故可用于计算样品中PCBs的生物有效性.该地区居民每天通过动物性食品摄入的PCBs量为24439.3pg/d,以PCBs的生物有效性计量为5034.5pg/d.对不同暴露源(包括灰尘和大气颗粒物)的分析表明,鱼类是PCBs人体暴露的主要贡献者,约占人体PCBs日暴露的60%. 相似文献
805.
ABSTRACTDifferent human societies shape landscapes differently. Anthroecology theory explains this long-term differential shaping of landscapes as the product of sociocultural niche construction (SNC): an evolutionary theory coupling social change with ecosystem engineering. The evolutionary mechanisms underpinning this theory cannot be tested without experimental approaches capable of reproducing emergent selection processes acting on the combined suite of cultural, material, and ecological inheritances that determine the adaptive fitness of human individuals, groups, and societies. Agent-based modeling, as a ‘generative social science’ tool, appears ideal for this. Here we propose an agent-based virtual laboratory (ABVL) approach to generating and testing basic hypotheses on SNC as a general mechanism capable of producing the broadly varied anthroecological forms and dynamics of human landscapes from prehistory to present. While major challenges must still be overcome, a prospective modeling framework specification, guiding questions, and illustrative examples demonstrate clear potential for an ABVL to test predictions of anthroecology theory through generative social simulation. 相似文献
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807.
基于分子对接方法探讨了多溴二苯醚(PBDEs)类化合物与人雌激素受体α亚型间的分子作用机理.对多溴二苯醚类化合物是否具有拟雌激素功能的研究得出:可通过对接打分值和化合物结构特征来推测PBDEs母体化合物是否具有拟雌激素活性;对HO-PBDEs,与氨基酸残基GLU53和/或ARG394形成氢键可能是影响其拟雌激素活性的重要因素;对MeO-PBDEs,疏水MeO-位于结合腔的疏水中部有利于拟雌激素活性.从结构及构象分析得出,邻位疏水基(Br-、MeO-)有利于PBDEs类化合物的拟雌激素活性.同时对多溴二苯醚类化合物是否具有抗雌激素功能的结合特征研究发现,表现出抗雌激素活性的部分PBDEs类化合物伸进通常被雌激素受体拮抗剂雷洛昔芬和4-羟基它莫西芬的烷基胺侧链占据的通道,而大多数未表现出抗雌激素活性的PBDEs类化合物的结合模式类似雌激素受体激动剂17β-雌二醇,位于结合腔,没有伸进通道.本研究从化合物结构及化合物在受体内结合的构象特征上解释化合物活性不同的原因,以期能够利用构象分析得到的结果进行筛选. 相似文献
808.
Polybrominated diphenyl ethers (PBDEs) are brominated flame retardants (BFRs) which have recently been detected in human blood and milk in the USA, and presently these PBDE levels are found to be the highest globally. On a population basis, individual blood and individual milk analyses show similar congener patterns and levels. Until now, there has not been a study comparing PBDE levels in milk and blood of the same individuals. This study is the first to report these levels for PBDEs, though partitioning between blood and milk has been done previously for dioxins and polychlorinated biphenyls (PCBs). Twelve congeners in 11 nursing mothers’ blood and milk were found and the data describe partitioning ratios between blood and milk. The data suggest it may be easier for smaller, less brominated congeners to move from blood to milk. 相似文献
809.
Nowadays, much attention is devoted to the study of toxic elements at trace and sub-trace levels in the investigation of particulate matter composition, especially in PM10 and PM2.5. Furthermore, it should be considered that the behavior knowledge is an other important task for understanding such species. Finally, the determination of particular elements with a few data in literature can assume relevant importance in industrial processes (Pd, Rh, Ir, etc. for catalytic pot, Sm, Ce, Eu, etc. for optical fibers and electronic process). In this article, we apply a nuclear technique, i.e. Instrumental Neutron Activation Analysis, for the study of metal composition in fine and coarse fractions. This nuclear technique allows the determination of about 25 elements: for some of them, this is the first determination in the ambient air of Rome. The investigation was performed in a reserved area in downtown Rome during a 15-day intensive campaign. The sampled filters were irradiated at the nuclear reactor Triga Mark II (ENEA-Casaccia Laboratories) at neutron flux of 2.6?×?1012?n?cm?2?s?1 for 32.55?h. The measurements of the γ-ray allow the qualitative and quantitative analysis. The element levels in fine and coarse fractions will be shown with the correlations among some elements being more interesting in the toxicological field: basically, the concentrations are very low. 相似文献
810.
The presence of organochlorine compounds (OC) such as DDT and their metabolites in the environment have created a significant environmental concern over the years due to adverse effects. Consequently, DDT has been banned in many countries. However, it is still used in some countries including South Africa, particularly for vector-borne disease eradication programmes. Since the presence of DDT and its metabolites may provide an indication of the general exposure and use of these compounds, there was a need for such a study. Human breast milk samples (n = 30) were collected from mothers within the age range of 19–40 years from the Thohoyandou area, South Africa. The liquid–liquid extraction method was used to extract DDT and its metabolites from the samples. The crude extracts were subjected to column chromatography for measurements of OC levels. The concentration ranges of the contaminants were as follows: not detected (ND) to1770 ng g?1 (2,4′-DDE); ND to 3977 ng g?1 (4,4′-DDE); ND to 3250 ng g?1 (2,4′-DDD); ND to 2580 ng g?1 (4,4′-DDD) and ND to 2847 ng g?1 (4,4′-DDT). The mean ΣDDE, ΣDDD and ΣDDT obtained from the villages were 1180 ng g?1, 830 ng g?1 and 690 ng g?1, respectively. The total DDT ranged from 820–7473 ng g?1. The estimated daily intake varied from 260 to 4696 ng g?1, ND-10551 ng g?1 and ND-4237 ng g?1 for DDE, DDD and DDT, respectively. These values are significantly higher than the FAO/WHO acceptable daily intake (ADI) of 20 ng g?1. The ΣDDT was found to decrease with increasing age of the mothers. The observed high levels of DDE compared to DDT indicated chronic exposure of the mothers to DDT, which is metabolized to DDE and retained in the body. 相似文献