全文获取类型
收费全文 | 1560篇 |
免费 | 81篇 |
国内免费 | 647篇 |
专业分类
安全科学 | 68篇 |
废物处理 | 122篇 |
环保管理 | 105篇 |
综合类 | 912篇 |
基础理论 | 273篇 |
环境理论 | 2篇 |
污染及防治 | 564篇 |
评价与监测 | 78篇 |
社会与环境 | 51篇 |
灾害及防治 | 113篇 |
出版年
2023年 | 24篇 |
2022年 | 87篇 |
2021年 | 81篇 |
2020年 | 43篇 |
2019年 | 48篇 |
2018年 | 52篇 |
2017年 | 60篇 |
2016年 | 75篇 |
2015年 | 94篇 |
2014年 | 118篇 |
2013年 | 126篇 |
2012年 | 112篇 |
2011年 | 144篇 |
2010年 | 122篇 |
2009年 | 102篇 |
2008年 | 102篇 |
2007年 | 71篇 |
2006年 | 93篇 |
2005年 | 51篇 |
2004年 | 64篇 |
2003年 | 48篇 |
2002年 | 58篇 |
2001年 | 48篇 |
2000年 | 56篇 |
1999年 | 55篇 |
1998年 | 55篇 |
1997年 | 62篇 |
1996年 | 46篇 |
1995年 | 44篇 |
1994年 | 28篇 |
1993年 | 36篇 |
1992年 | 19篇 |
1991年 | 13篇 |
1990年 | 10篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 5篇 |
1930年 | 1篇 |
排序方式: 共有2288条查询结果,搜索用时 140 毫秒
661.
Maolin Li Xianshi Jin Qisheng Tang 《Journal of Agricultural and Environmental Ethics》2012,25(1):33-54
Marine ecosystems are in serious troubles globally, largely due to the failures of fishery resources management. To restore
and conserve fishery ecosystems, we need new and effective governance systems urgently. This research focuses on fisheries
management in ancient China. We found that from 5,000 years ago till early modern era, Chinese ancestors had been constantly
enthusiastic about sustainable utilization of fisheries resources and natural balance of fishery development. They developed
numerous rigorous policies and regulations to guide people to act on natural laws. Being detailed and scientific, the legal
systems had gained gratifying enforcement, due to official efforts and folks’ voluntary participation in resource management.
In-depth analyses show that people’s consciousness of ecological conservation was derived from the edification of kinds of
ancient eco-ethical wisdom, such as totemism, nature worship, Zhou Yi, Taoism, Buddhism, Confucianism, Mohism, etc. All this Chinese classical wisdom have the same cores: “Nature and Man in One”
spirit, frugality and “All things are equal” concept. The findings show that eco-ethical thinking is never inconsistent with
social ethic systems, and it’s of great importance to give legal effect to usual ecological moral claims and eco-ethical requirements
of the public in protecting the environment. The eco-ethical wisdom is efficient in assisting and urging people to fulfill
humans’ obligation for nature. Finally, it’s believed that present world fisheries management will benefit a lot from all
these ancient Chinese thoughts and practices. People are expected to make the most of the eco-ethical wisdom, strengthen fishery
legislation and fully stimulate their voluntary participation in both marine fishery resources conservation and fishery cyclic
economy. 相似文献
662.
采用聚乙二醇活化原材料百合杆,分别在300%和600℃对活化后百合杆进行炭化,制得炭化百合杆,用于吸附废水中的苯酚。实验考察了pH值、吸附时间和吸附质初始浓度对苯酚吸附的影响,采用Langmuir、Freundlich和Dubinin.Radushkevich等温式分别对该吸附过程进行描述,并结合实验数据对比了准一级和准二级动力学模型。结果表明:炭化百合杆对苯酚的吸附过程符合Langmuir等温式和准二级动力学模型,计算了热力学参数(△G、△H和△s),说明该吸附过程为自发进行。碳化百合杆对苯酚具有良好吸附性能。 相似文献
663.
Tang X Chen J Wang WH Liu TW Zhang J Gao YH Pei ZM Zheng HL 《Environmental pollution (Barking, Essex : 1987)》2011,159(12):3784-3792
This study characterized the changes of nitric oxide (NO) production during the growth of Microcystis aerugrinosa, a cyanobacterium which usually cause cyanobacterial blooms. Results showed a drastic NO release accompanying with cell density and Chl-a content sharp rises when M. aerugrinosa grew from fifth day to sixth day. Moreover, high N:P ratio accelerated the cyanobacterial growth and NO burst. Sodium nitroprusside, an exogenous NO donor, promoted M. aerugrinosa growth with the optimal concentration of 0.1 mg/L. Experiments by supplementing with sodium nitrite and l-arginine demonstrated NO production in M. aerugrinosa cells was mainly through nitrate reductase (NR) pathway while minorly through NO synthase pathway. All these data suggested M. aerugrinosa produced increasing NO during its growth mainly by NR pathway, during which NO positively regulated the growth of M. aerugrinosa. 相似文献
664.
Hogrefe C Isukapalli SS Tang X Georgopoulos PG He S Zalewsky EE Hao W Ku JY Key T Sistla G 《Journal of the Air & Waste Management Association (1995)》2011,61(1):92-108
The role of emissions of volatile organic compounds and nitric oxide from biogenic sources is becoming increasingly important in regulatory air quality modeling as levels of anthropogenic emissions continue to decrease and stricter health-based air quality standards are being adopted. However, considerable uncertainties still exist in the current estimation methodologies for biogenic emissions. The impact of these uncertainties on ozone and fine particulate matter (PM2.5) levels for the eastern United States was studied, focusing on biogenic emissions estimates from two commonly used biogenic emission models, the Model of Emissions of Gases and Aerosols from Nature (MEGAN) and the Biogenic Emissions Inventory System (BEIS). Photochemical grid modeling simulations were performed for two scenarios: one reflecting present day conditions and the other reflecting a hypothetical future year with reductions in emissions of anthropogenic oxides of nitrogen (NOx). For ozone, the use of MEGAN emissions resulted in a higher ozone response to hypothetical anthropogenic NOx emission reductions compared with BEIS. Applying the current U.S. Environmental Protection Agency guidance on regulatory air quality modeling in conjunction with typical maximum ozone concentrations, the differences in estimated future year ozone design values (DVF) stemming from differences in biogenic emissions estimates were on the order of 4 parts per billion (ppb), corresponding to approximately 5% of the daily maximum 8-hr ozone National Ambient Air Quality Standard (NAAQS) of 75 ppb. For PM2.5, the differences were 0.1-0.25 microg/m3 in the summer total organic mass component of DVFs, corresponding to approximately 1-2% of the value of the annual PM2.5 NAAQS of 15 microg/m3. Spatial variations in the ozone and PM2.5 differences also reveal that the impacts of different biogenic emission estimates on ozone and PM2.5 levels are dependent on ambient levels of anthropogenic emissions. 相似文献
665.
666.
667.
668.
669.
670.