全文获取类型
收费全文 | 375篇 |
免费 | 4篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 20篇 |
废物处理 | 19篇 |
环保管理 | 108篇 |
综合类 | 19篇 |
基础理论 | 48篇 |
污染及防治 | 125篇 |
评价与监测 | 25篇 |
社会与环境 | 18篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 3篇 |
2022年 | 11篇 |
2021年 | 10篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 31篇 |
2012年 | 9篇 |
2011年 | 20篇 |
2010年 | 11篇 |
2009年 | 19篇 |
2008年 | 22篇 |
2007年 | 20篇 |
2006年 | 16篇 |
2005年 | 13篇 |
2004年 | 15篇 |
2003年 | 8篇 |
2002年 | 11篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 11篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有385条查询结果,搜索用时 31 毫秒
141.
What to do about fisheries collapse and the decline of large fishes in marine ecosystems is a critical debate on a global scale. To address one aspect of this debate, a major fisheries management action, the removal of gill nets in 1994 from the nearshore arena in the Southern California Bight (34°26′30″N, 120°27′09″W to 33°32′03″N, 117°07′28″W) was analyzed. First, the impetus for the gill net ban was the crash of the commercial fishery for white seabass (Atractoscion nobilis; Sciaenidae) in the early 1980s. From 1982 to 1997 catch remained at a historically low level (47.8 ± 3.0 mt) when compared to landings from 1936–1981, but increased significantly from 1995–2004 (r = 0.89, P < 0.01) to within the 95% confidence limit of the historic California landings. After the white seabass fishery crashed in the early 1980s, landings of soupfin (Galeorhinus galeus; Triakidae) and leopard shark (Triakis semifasciata; Triakidae) also significantly declined (r = 0.95, P < 0.01 and r = 0.91, P < 0.01, respectively) until the gill net closure. After the closure both soupfin and leopard shark significantly increased in CPUE (r = 0.72, P = 0.02 and r = 0.87, P < 0.01, respectively). Finally, giant sea bass (Stereolepis gigas; Polyprionidae) the apex predatory fish in this ecosystem, which was protected from commercial and recreational fishing in 1981, were not observed in a quarterly scientific SCUBA monitoring program from 1974 to 2001 but reappeared in 2002–2004. In addition, CPUE of giant seabass increased significantly from 1995 to 2004 (r = 0.82, P < 0.01) in the gill net monitoring program. The trends in abundance of these fishes return were not correlated with sea surface temperature (SST), the Pacific Decadal Oscillation (PDO) or the El Niño/Southern Oscillation (ENSO). All four species increased significantly in either commercial catch, CPUE, or in the SCUBA monitoring program after the 1994 gill net closure, whereas they had declined significantly, crashed, or were absent prior to this action. This suggests that removing gill nets from coastal ecosystems has a positive impact on large marine fishes. 相似文献
142.
143.
144.
Jake Edmunds Glenn Tootle Greg Kerr Ramesh Sivanpillai Larry Pochop 《Journal of the American Water Resources Association》2012,48(1):187-196
Edmunds, Jake, Glenn Tootle, Greg Kerr, Ramesh Sivanpillai, and Larry Pochop, 2011. Glacier Variability (1967‐2006) in the Teton Range, Wyoming, United States. Journal of the American Water Resources Association (JAWRA) 48(1): 187‐196. DOI: 10.1111/j.1752‐1688.2011.00607.x Abstract: Glacier area and volume changes were quantified through the use of historical aerial photographs in Wyoming’s Teton Range. Glacier area changes in the Teton Range were estimated for three glaciers using unrectified aerial photography from 1967 to 2006. The total surface area of the three glaciers was 0.53 km2 in 1967 and 0.40 km2 in 2006, a decrease of 25% during the 39‐year period. The smallest glacier, Teepe, experienced the greatest area loss (60 ± 3%), whereas the largest glacier, Teton Glacier, lost 17 ± 3% of the 1967 area. For the current research, aerial photography from 1967 to 2002 was used to estimate glacier volume loss using stereoscopy techniques. The aerial photographs provide a finer resolution when compared with other datasets including satellite imagery (e.g., Landsat). Volume loss for the three glaciers was estimated to be 3.20 ± 0.46 million cubic meters over the period of 1967 to 2002. In assessing the primary climatic driver of the glacier ice loss, observed summer (June, July, and August) temperature data showed a statistically significant increase in temperatures when comparing the period of study (1968 to 2006) with historical temperatures from 1911 to 1967. When comparing spring (April 1st Snow Water Equivalent) snowpack for the period of study with historical records beginning in 1931, a significant difference in snowpack was not observed. 相似文献
145.
Tabish Mohammad Khatoon Aisha Alkahtani Saad Alkahtane Abdullah Alghamdi Jawahir Ahmed Syed Anees Mir Snober S Albasher Gadah Almeer Rafa Al-Sultan Nouf K. Aljarba Nada H. Al-Qahtani Wedad Saeed AL-Zharani Mohammed Nayak Amit Kumar Hasnain Md Saquib 《Environmental science and pollution research international》2021,28(30):40311-40321
Environmental Science and Pollution Research - The World Health Organization (WHO) recognized a novel coronavirus as the causative agent of a new form of pneumonia. It was subsequently named... 相似文献
146.
Bruce M. Rothschild Larry D. Martin Brendan Anderson Alison Olcott Marshall Craig P. Marshall 《Die Naturwissenschaften》2013,100(8):789-794
Discovery of a fossil (30–35 million-year-old) urolith from Early Oligocene deposits in northeastern Colorado provides the earliest evidence for the antiquity of bladder stones. These are spherical objects with a layered phosphatic structure and a hollow center. Each layer is composed of parallel crystals oriented perpendicular to the surface. Macroscopic and microscopic examination and X-ray diffraction analysis, along with comparison with 1,000 contemporary uroliths, were used as evidence in the confirmation of this diagnosis. Raman microspectroscopy verified the presence of organic material between layers, confirming its biologic origin. 相似文献
147.
Lee LA Lee EG Lee T Kim SW Slaven JE Harper M 《Journal of environmental monitoring : JEM》2011,13(3):527-535
Recent laboratory research indicates physiologic sampling of gas and vapor may provide more representative estimates of personal exposures than traditional methods. Modifications to the physiologic sampling pump (PSP) used in that research are described which extend its usefulness to size-selective sampling of particulates. PSPs used in previous research varied motor speed to keep sampling proportional to the subject's inhalation. This caused airflow and particle velocities through the collection device to continually change making those pumps unsuitable for sampling particulates. The modified implementation of the PSP pulls a constant airflow into and through a cyclone, then uses valves to either direct the airflow through, or divert the airflow around, the sampling filter. By using physiologic inputs to regulate the fraction of each second that air flows through the sampling filter, samples may be collected in proportion to inhalation rate. To evaluate the performance of a functional prototype 5 different sizes of monodisperse aerosols of ammonium fluorescein were generated by a vibrating orifice aerosol generator and introduced into a calm air chamber. To simulate different inhalation rates the valves of the PSP were energized using 9 different duty cycles. Efficiency curves are presented and compared to a standard respirable convention by bias mapping. The performance of the modified cyclone used in the PSP sampling head compared favorably with a commercially available cyclone of the same model, operating at a constant airflow (± 10% over almost all the size distributions of concern). The new method makes physiologic sampling of the respirable fraction of particulates feasible. 相似文献
148.
C. Biney D. Calamari H. Naeve T. W. Maembe B. Nyakageni M. A. H. Saad 《Chemistry and Ecology》1987,3(1):49-74
The awareness of the harm caused by pollutants to natural environments has led the political and legislative authorities of industrially-developed countries to introduce or review regulations to protect the environment. However, in recent years, all over the world and particularly in many countries in Africa, there has been a remarkable population growth, accompanied by an intense urbanization, an increase of industrial activities and a higher exploitation of cultivable land. These transformations have brought about a huge increase in the quantity of discharges and a wide diversification in the types of pollutants that reach river waters and have undesirable effects on fish and on the potential for fishery exploitation. 相似文献
149.
150.
Samia Galal Saad 《Natural resources forum》1996,20(2):135-144
The global concern for the survival of the planet earth draws particular attention to the Third World countries and the impact of degrading forces on sustainable development. A different response to the growing ecological crisis has recently come to the fore. This response comes from women engaged in the struggle for survival. Women in the Third World, because of their situation on the fringes of society and their role producing sustenance, are often able to offer ecological insights that are deeper and richer than the recipes of technocrats and international experts or ideas resulting from enquiries addressed only to the men in communities. In the following the author seeks to demonstrate how women often bear the brunt of suffering resulting from environmental degradation, wars and poverty that plague the Near East region. However, training of women, especially poor women, in environmental management, and the active participation of local women in community and regional decision making holds a clear promise of eventually controlling the vicious circle of poverty and environmental degradation. An intermediate step is the coordination of NGO activities in a common front for environmental protection and income generation for the poor. Further training of the NGO's own staff in the design and implementation of such projects is also required. 相似文献