全文获取类型
收费全文 | 42358篇 |
免费 | 403篇 |
国内免费 | 291篇 |
专业分类
安全科学 | 1207篇 |
废物处理 | 2324篇 |
环保管理 | 5720篇 |
综合类 | 5725篇 |
基础理论 | 11525篇 |
环境理论 | 11篇 |
污染及防治 | 9699篇 |
评价与监测 | 3308篇 |
社会与环境 | 3319篇 |
灾害及防治 | 214篇 |
出版年
2023年 | 150篇 |
2022年 | 288篇 |
2021年 | 352篇 |
2020年 | 242篇 |
2019年 | 298篇 |
2018年 | 1895篇 |
2017年 | 1865篇 |
2016年 | 1956篇 |
2015年 | 724篇 |
2014年 | 970篇 |
2013年 | 2742篇 |
2012年 | 1609篇 |
2011年 | 2774篇 |
2010年 | 1945篇 |
2009年 | 1874篇 |
2008年 | 2417篇 |
2007年 | 2676篇 |
2006年 | 1376篇 |
2005年 | 1273篇 |
2004年 | 1194篇 |
2003年 | 1217篇 |
2002年 | 1209篇 |
2001年 | 1197篇 |
2000年 | 839篇 |
1999年 | 546篇 |
1998年 | 420篇 |
1997年 | 434篇 |
1996年 | 444篇 |
1995年 | 510篇 |
1994年 | 438篇 |
1993年 | 383篇 |
1992年 | 408篇 |
1991年 | 383篇 |
1990年 | 355篇 |
1989年 | 346篇 |
1988年 | 315篇 |
1987年 | 256篇 |
1986年 | 261篇 |
1985年 | 268篇 |
1984年 | 302篇 |
1983年 | 284篇 |
1982年 | 288篇 |
1981年 | 248篇 |
1980年 | 183篇 |
1979年 | 198篇 |
1978年 | 172篇 |
1977年 | 137篇 |
1975年 | 141篇 |
1973年 | 169篇 |
1972年 | 144篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
11.
Srichandan Suchismita Baliarsingh Sanjiba Kumar Prakash Satya Lotliker Aneesh A. Parida Chandanlal Sahu Kali Charan 《Environmental science and pollution research international》2019,26(12):12025-12041
Environmental Science and Pollution Research - Seasonal distribution of phytoplankton community and size structure was assessed in three different tropical ecosystems of the western Bay of Bengal... 相似文献
12.
Peter Wimmer Michael Düring Henri Chajmowicz Fredrik Granum Julian King Harald Kolk 《Traffic injury prevention》2019,20(4):S139-S145
AbstractObjective: With the overall goal to harmonize prospective effectiveness assessment of active safety systems, the specific objective of this study is to identify and evaluate sources of variation in virtual precrash simulations and to suggest topics for harmonization resulting in increased comparability and thus trustworthiness of virtual simulation-based prospective effectiveness assessment.Methods: A round-robin assessment of the effectiveness of advanced driver assistance systems was performed using an array of state-of-the-art virtual simulation tools on a set of standard test cases. The results were analyzed to examine reasons for deviations in order to identify and assess aspects that need to be harmonized and standardized. Deviations between results calculated by independent engineering teams using their own tools should be minimized if the research question is precisely formulated regarding input data, models, and postprocessing steps.Results: Two groups of sources of variations were identified; one group (mostly related to the implementation of the system under test) can be eliminated by using a more accurately formulated research question, whereas the other group highlights further harmonization needs because it addresses specific differences in simulation tool setups. Time-to-collision calculations, vehicle dynamics, especially braking behavior, and hit-point position specification were found to be the main sources of variation.Conclusions: The study identified variations that can arise from the use of different simulation setups in assessment of the effectiveness of active safety systems. The research presented is a first of its kind and provides significant input to the overall goal of harmonization by identifying specific items for standardization. Future activities aim at further specification of methods for prospective assessments of the effectiveness of active safety, which will enhance comparability and trustworthiness in this kind of studies and thus contribute to increased traffic safety. 相似文献
13.
14.
Kumar Shalender Rajesh Kumar Yadav 《Environment, Development and Sustainability》2018,20(6):2587-2607
The purpose of the research is to identify the critical challenges that are impeding the adoption of e-mobility in India. It also aims to give a roadmap how to address these challenges while taking into considerations concerns of all the relevant stakeholders. Based on an in-depth literature review, an exploratory research design is employed to delve deep into various aspects of e-mobility. This is followed by a three-phase Delphi technique to identify and rate the e-mobility challenges in the Indian context. The study successfully identifies four different categories of challenges and proposes integrative framework for e-mobility. Further, the research goes on to lay out the future roadmap for mass adoption of electric vehicles (EVs) in India. The research is novel in terms of presenting a holistic viewpoint on e-mobility in India. Its originality lies in identifying the major inhibitors obstructing EVs adoption in India and then suggesting the roadmap how to overcome these impediments for mass adoption of e-mobility. 相似文献
15.
16.
Erica Marshall Roozbeh Valavi Louise O’ Connor Natasha Cadenhead Darren Southwell Brendan A. Wintle Heini Kujala 《Conservation biology》2021,35(2):567-577
Developers are often required by law to offset environmental impacts through targeted conservation actions. Most offset policies specify metrics for calculating offset requirements, usually by assessing vegetation condition. Despite widespread use, there is little evidence to support the effectiveness of vegetation-based metrics for ensuring biodiversity persistence. We compared long-term impacts of biodiversity offsetting based on area only; vegetation condition only; area × habitat suitability; and condition × habitat suitability in development and restoration simulations for the Hunter Region of New South Wales, Australia. We simulated development and subsequent offsetting through restoration within a virtual landscape, linking simulations to population viability models for 3 species. Habitat gains did not ensure species persistence. No net loss was achieved when performance of offsetting was assessed in terms of amount of habitat restored, but not when outcomes were assessed in terms of persistence. Maintenance of persistence occurred more often when impacts were avoided, giving further support to better enforce the avoidance stage of the mitigation hierarchy. When development affected areas of high habitat quality for species, persistence could not be guaranteed. Therefore, species must be more explicitly accounted for in offsets, rather than just vegetation or habitat alone. Declines due to a failure to account directly for species population dynamics and connectivity overshadowed the benefits delivered by producing large areas of high-quality habitat. Our modeling framework showed that the benefits delivered by offsets are species specific and that simple vegetation-based metrics can give misguided impressions on how well biodiversity offsets achieve no net loss. 相似文献
17.
18.
Maheswari C. Ramya A. S. Priya B. Meenakshi Sudhahar S. Prabhu Raj B. Lokesh B. Ramani G. 《Journal of Material Cycles and Waste Management》2021,23(6):2255-2265
Journal of Material Cycles and Waste Management - The present research work focused on fabricating Biodegradable Plate (BD plate) composed of rice husk ash, bagasse and corn starch which is... 相似文献
19.
Quantitative methods have been applied to the study of floristic structure and diversity in Samarskaya Luka. The results show that Samarskaya Luka is a floristically heterogeneous area in which six elementary floras can be distinguished. This area has been assessed as a floristically autonomous formation, and its floristic representativeness was estimated. 相似文献
20.