全文获取类型
收费全文 | 578篇 |
免费 | 13篇 |
国内免费 | 9篇 |
专业分类
安全科学 | 27篇 |
废物处理 | 17篇 |
环保管理 | 138篇 |
综合类 | 86篇 |
基础理论 | 109篇 |
污染及防治 | 175篇 |
评价与监测 | 20篇 |
社会与环境 | 23篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 9篇 |
2020年 | 4篇 |
2019年 | 12篇 |
2018年 | 11篇 |
2017年 | 14篇 |
2016年 | 19篇 |
2015年 | 18篇 |
2014年 | 15篇 |
2013年 | 74篇 |
2012年 | 23篇 |
2011年 | 34篇 |
2010年 | 24篇 |
2009年 | 26篇 |
2008年 | 33篇 |
2007年 | 36篇 |
2006年 | 31篇 |
2005年 | 10篇 |
2004年 | 18篇 |
2003年 | 14篇 |
2002年 | 22篇 |
2001年 | 12篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 11篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 9篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1977年 | 5篇 |
1972年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有600条查询结果,搜索用时 15 毫秒
501.
A. Allen Bradley Forrest M. Holly William K. Walker Scott A. Wright 《Journal of the American Water Resources Association》1998,34(3):467-480
ABSTRACT: A continuous simulation approach is proposed for estimating water temperature exceedance probabilities using thermo-hydrodynamic modeling. The approach uses (1) a deterministic unsteady flow and heat transport model, (2) continuous hydrological and meteorological data for a long historical period, and (3) synthetic records of tributary water temperatures and other model inputs. Representative historical records of streamflow, air temperatures, and other hydrometeorological variables are obtained from nearby gages. Stochastic modeling methods are used to construct synthetic records for other model inputs, including inflow water temperatures. An application of this deterministic-stochastic approach is presented for a complex waterway in northeastern Illinois with heat discharges from several power plants and wastewater treatment plants. Statistical results from the continuous simulations are compared to results obtained from traditional event simulations. The application illustrates the information that engineers and biologists can obtain for (1) evaluating compliance with water temperature standards, and (2) assessing the effect of water temperatures on aquatic habitat. 相似文献
502.
K. Toftager-Larsen R. J. Benzie T. A. Doran M. Miskin L. C. Allen L. Becker 《黑龙江环境通报》1983,3(1):35-40
Based on data from 5 cases of fetal cystic hygroma (4 cases of Turner's Syndrome and one case of Trisomy 18) and one case of Down's Syndrome with severe subcutaneous oedema, it is concluded that amniotic fluid alpha-fetoprotein (AFP) is normal or only slightly elevated in such cases whereas AFP in fluid from the cystic structures is very high. Reported high values of ‘amniotic fluid’ AFP are therefore likely to have been obtained from fluids accidentally drawn from the cystic structures. Fluids from the two sources cannot be distinguished from each other visually. In support of this theory is that the maternal serum AFP was found to be normal in all cases where investigated. In the diagnosis of cystic hygromata detailed ultrasound scanning will reveal the correct diagnosis. 相似文献
503.
504.
505.
W. Allen Hogge M.D. Carol Blank Linda B. Roochvarg Joan S. Hogge Eric A. Wulfsberg Leslie J. Raffel 《黑龙江环境通报》1994,14(8):725-727
The Gorlin (naevoid basal cell carcinoma) syndrome is an autosomal dominant disorder consisting principally of naevoid basal cell carcinomas, odontogenic keratocysts, skeletal abnormalities, and intracranial calcification. We report the prenatal detection of the Gorlin syndrome by ultrasonography in a fetus with macrocephaly and mild ventriculomegaly. 相似文献
506.
Eight patients were referred for prenatal diagnosis for suspected fetal cytomegalovirus infection (CMV): six for documented first-trimester infection and two for abnormal ultrasound evaluation suggestive of fetal infection. Three methods of diagnosis were employed: (1) amniotic fluid viral cultures and CMV-specific IgM in fetal serum; (2) amniotic fluid cultures and detection by polymerase chain reaction amplification of CMV-specific DNA in chorionic villi; and (3) detection of CMV-specific DNA in villus samples only. Amniotic fluid cultures detected all cases of infection, but CMV-specific IgM was not a reliable indicator of infection in any case. DNA analysis correlated well with both culture results and clinical outcome. 相似文献
507.
508.
Potassium silicate drilling fluids(PSDF) are a waste product of the oil and gas industry with potential for use in land reclamation. Few studies have examined the influence of PSDF on abundance and composition of soil bacteria and fungi. Soils from three representative locations for PSDF application in Alberta, Canada, with clay loam, loam and sand textures were studied with applications of unused, used once and used twice PSDF. For all three soils, applying ≥ 40 m3/ha of used PSDF significantly affected the existing soil microbial flora. No microbiota was detected in unused PSDF without soil. Adding used PSDF to soil significantly increased total fungal and aerobic bacterial colony forming units in dilution plate counts, and anaerobic denitrifying bacteria numbers in serial growth experiments.Used PSDF altered bacterial and fungal colony forming unit ratios of all three soils. 相似文献
509.
Potassium silicate drilling fluids (PSDF) are a waste product of the oil and gas industry with potential for use in land reclamation. Few studies have examined the influence of PSDF on abundance and composition of soil bacteria and fungi. Soils from three representative locations for PSDF application in Alberta, Canada, with clay loam, loam and sand textures were studied with applications of unused, used once and used twice PSDF. For all three soils, applying ≥40 m3/ha of used PSDF significantly affected the existing soil microbial flora. No microbiota was detected in unused PSDF without soil. Adding used PSDF to soil significantly increased total fungal and aerobic bacterial colony forming units in dilution plate counts, and anaerobic denitrifying bacteria numbers in serial growth experiments. Used PSDF altered bacterial and fungal colony forming unit ratios of all three soils. 相似文献
510.
Allen S. Heagle John W. Johnston 《Journal of the Air & Waste Management Association (1995)》2013,63(7):729-732
Foliar injury and shoot fresh weight responses of soybeans (Glycine max L.) ‘Lee 68’ and ‘Dare’ exposed to mixtures of ozone (O3) and sulfur dioxide (SO2) were greater than additive (synergistic), less than additive (antagonistic), or additive. The result depended on the concentrations of O3 and SO2, the exposure duration, and the amount of injury caused by each gas singly. Synergism usually occurred when injury from O3 or SO2 singly was slight to moderate. Antagonism usually occurred when injury from either gas singly was severe. In many cases of antagonism, the injury and fresh weight effects of the mixture were less than those from SO2 alone, suggesting that O3 can sometimes protect soybeans from SO2. 相似文献