全文获取类型
收费全文 | 234篇 |
免费 | 19篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 15篇 |
废物处理 | 2篇 |
环保管理 | 68篇 |
综合类 | 58篇 |
基础理论 | 46篇 |
污染及防治 | 50篇 |
评价与监测 | 5篇 |
社会与环境 | 4篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 2篇 |
2021年 | 3篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 9篇 |
2016年 | 6篇 |
2015年 | 7篇 |
2014年 | 4篇 |
2013年 | 16篇 |
2012年 | 9篇 |
2011年 | 9篇 |
2010年 | 10篇 |
2009年 | 11篇 |
2008年 | 10篇 |
2007年 | 10篇 |
2006年 | 10篇 |
2005年 | 5篇 |
2004年 | 13篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1996年 | 6篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1984年 | 2篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1972年 | 2篇 |
1963年 | 2篇 |
1961年 | 2篇 |
1960年 | 2篇 |
1946年 | 2篇 |
1937年 | 1篇 |
1936年 | 1篇 |
1932年 | 1篇 |
1926年 | 1篇 |
1922年 | 1篇 |
1919年 | 2篇 |
1913年 | 4篇 |
排序方式: 共有254条查询结果,搜索用时 31 毫秒
171.
John P. Newnham M.R.C.O.G. John V. Crues III Arnold L. Vinstein Arnold L. Medearis 《黑龙江环境通报》1984,4(6):467-471
A case of prenatal sonographic detection of a posterior mediastinal cyst in an otherwise normal fetus is presented. Following surgical excision 5 days after birth, histological examination confirmed the cyst to be gastroenteric. The differential diagnosis and clinical value of prenatal detection are discussed. 相似文献
172.
This paper reports on successful prenatal diagnosis of X-linked anhidrotic ectodermal dysplasia (AED) by means of light and electron microscopy on fetal skin biopsies obtained under fetoscopy. In the present family two brothers of the proband were severely affected with the full symptomatology of AED, the pregnant female and her mother revealed minor symptoms with patches of skin lacking vellus hair. Control of lesional skin of the affected family members by electron microscopy revealed no ultrastructural abnormalities. However, all biopsies lacked skin appendages including hair follicles, sebaceous glands, and sweat glands. The lack of pilosebaceous follicles can be used as a diagnostic criterion since these structures are fully developed in normal fetuses of 20 weeks whereas the development of sweat glands does not start before week 20 to 24 of fetal life. Skin biopsies were taken from various regions of the fetus at risk via fetoscopy in week 20 and processed for light and electron microscopy. All samples revealed complete absence of all skin appendages in contrast to a total of 61 non-AED fetuses. Thus positive prenatal diagnosis of AED was made and the pregnancy was terminated. Control investigations after abortion confirmed the diagnosis. 相似文献
173.
Dr. Hans Arnold 《Die Naturwissenschaften》1913,1(36):862-865
174.
175.
176.
177.
178.
Daniel E. Line Jon A. Arnold Gregory D. Jennings Jy Wu 《Journal of the American Water Resources Association》1996,32(4):807-816
ABSTRACT: This study was to designed to determine concentrations of selected metals, organic compounds, pesticides, and conventional pollutants in stormwater runoff from two North Carolina businesses in each of the following five general industrial groups: auto salvage, metal fabrication, scrap and recycling, vehicle maintenance, and wood preserving facilities. The sampling procedure involved collecting a first flush sample of runoff from a single storm event and both first flush and composite samples of runoff from three consecutive storm events. Analysis of samples collected during the first flush indicated that zinc and copper were the most common of the 13 metals included in the analysis. Additional analysis documented that several volatile organic, semi-volatile organic, or pesticide compounds including acrolein, methylene chloride, xylenes, toluene, tetrachloroethylene, trichloroethylene, pentachlorophenol, and aldrin were also found in the first flush samples. Concentrations of aggregate organics, nitrogen, phosphorus, and sediment were determined in both first flush and three-hour composite samples. Concentrations of pollutants in first flush samples were similar to those in corresponding composite samples. 相似文献
179.
J. G. Arnold M. D. Bircket J. R. Williams W. F. Smith H. N. McGill 《Journal of the American Water Resources Association》1987,23(6):1101-1107
ABSTRACT: The dam impounding White Rock Lake was completed in 1910 to provide water for the City of Dallas. Since then, land use on the watershed has changed from entirely rural to over 77 percent urban. A model called SWRRB (Simulator for Water Resources in Rural Basins) was utilized to determine the effect of urbanization on water and sediment entering the lake. The simulation results show that, if urbanization had not occurred, then the annual surface runoff would be 135 mm rather than 151 mm and the annual sediment yield would be 4.4 t/ha rather than 4.1 t/ha. Also, the effect of urbanization on delivery ratios was shown and a positive linear correlation was found. Finally, the weather generator in SWRRB was utilized to estimate the loss of reservoir capacity until 2050 for three different land use management scenarios. 相似文献
180.
Arnold L. O'Brien 《Journal of the American Water Resources Association》1982,18(4):713-715
ABSTRACT: There are unpublished reports of rapid and large rises in the water table which are out of proportion to the infiltrated volumes of water. The phenomenon seems to result from the conversion of a tension saturated zone to phreatic water by one of several mechanisms. The effect could be triggered when the tension saturated zone intersects: the ground surface, a saturated soil horizon, or a coarse zone. The phenomenon could prove to be a common link in explaining several seemingly diverse phenomena which characterize non-Hortonian runoff in a humid environment. Under certain conditions storm peaks are dominated by flow from small, restricted, “variable source” areas that contributed runoff when saturated from below by rising water tables; for other streams, ground water input forms the major part of the flood peak. The explanation for these observations could lie in an understanding of the rapid water table rise phenomenon. Such a mechanism. if widespread, would provide the means for producing saturation at or near the surface shortly after rainfall commences. The phenomenon should be documented and closely analyzed from a number of perspectives to define its true role in the hydrology of humid environments. 相似文献