全文获取类型
收费全文 | 1426篇 |
免费 | 18篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 43篇 |
废物处理 | 47篇 |
环保管理 | 167篇 |
综合类 | 449篇 |
基础理论 | 256篇 |
环境理论 | 3篇 |
污染及防治 | 359篇 |
评价与监测 | 74篇 |
社会与环境 | 54篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 11篇 |
2022年 | 18篇 |
2021年 | 25篇 |
2020年 | 16篇 |
2019年 | 15篇 |
2018年 | 40篇 |
2017年 | 41篇 |
2016年 | 44篇 |
2015年 | 36篇 |
2014年 | 42篇 |
2013年 | 65篇 |
2012年 | 53篇 |
2011年 | 84篇 |
2010年 | 64篇 |
2009年 | 67篇 |
2008年 | 78篇 |
2007年 | 71篇 |
2006年 | 40篇 |
2005年 | 58篇 |
2004年 | 35篇 |
2003年 | 42篇 |
2002年 | 40篇 |
2001年 | 23篇 |
2000年 | 19篇 |
1999年 | 11篇 |
1998年 | 18篇 |
1997年 | 8篇 |
1996年 | 14篇 |
1995年 | 25篇 |
1994年 | 15篇 |
1993年 | 10篇 |
1992年 | 12篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 8篇 |
1987年 | 7篇 |
1986年 | 9篇 |
1984年 | 9篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1963年 | 8篇 |
1961年 | 11篇 |
1960年 | 7篇 |
1959年 | 8篇 |
1958年 | 14篇 |
1957年 | 8篇 |
1955年 | 7篇 |
1923年 | 6篇 |
1914年 | 6篇 |
排序方式: 共有1455条查询结果,搜索用时 31 毫秒
31.
32.
Joe C. Rutledge Arthur G. Weinberg Jan M. Friedman Mary Jo Harrod Rigoberto Santos-Ramos 《黑龙江环境通报》1986,6(1):51-61
In utero sonographic diagnoses from forty-five malformed infants were correlated with their autopsy findings. Fifty-two malformations were diagnosed prenatally in 42 of the patients but 90 additional malformations were not. Nine sonographically diagnosed abnormalities were not confirmed at autopsy. Factors compromising sonographic diagnosis included: limited examinations, small fetal size, timing of examination, oligohydramnios, fetal position, nature of the malformation and unfamiliarity of the ultrasonographer with specific malformation syndromes. In vitro ultrasonography is an invaluable tool of diagnosing congenital malformations but has limitations. 相似文献
33.
34.
35.
36.
Niels Gregersen Vibeke Winter Peter K. A. Jensen Anni Holmskov Steen Kølvraa Brage S. Andresen Ernst Christensen Peter Bross Jytte B. Lundemose Dr Markil Gregersen 《黑龙江环境通报》1995,15(1):82-86
Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is a potentially fatal inherited disease with a carrier frequency of approximately 1:100 in most Caucasian populations. The disease is implicated in sudden unexpected death in childhood. A prevalent disease-causing point mutation (A985G) in the MCAD gene has been characterized, thus rendering diagnosis easy in the majority of cases. Since the clinical spectrum of MCAD deficiency ranges from death in the first days of life to an asymptomatic life, there are probably other genetic factors—in addition to MCAD mutations—involved in the expression of the disease. Thus, families who have experienced the death of a child from MCAD deficiency might have an increased risk of a seriously affected subsequent child. In such a family we have therefore performed a prenatal diagnosis on a chorionic villus sample by a highly specific and sensitive polymerase chain reaction (PCR) assay for the G985 mutation. The analysis was positive and resulted in abortion. We verified the diagnosis by direct analysis on blood spots and other tissue material from the aborted fetus and from family members. 相似文献
37.
38.
39.
40.
Jan Kupec Kateřina Charvátová Milan Navrátil Vojtěch Křesálek Martina Křesálková 《Journal of Polymers and the Environment》2003,11(3):93-100
Most native polymers used in processing and application technologies are admittedly disposable from the environment in a biologic manner, but products possess low mechanical strength. One of the paths to increasing this attribute (if feasible) is their cross-linking, which may, however, affect their readiness to biodegradation. In the presented work this condition was observed on the example of waste protein (Hykol B) cross-linking by means of glutardialdehyde and glyoxal. Degree and course of cross-linking were determined through impedance spectroscopy. The objective of this work also was to obtain data for constructing a sensor capable of following the cross-linking course in real time, for potential industrial application of Hykol in continuous production. Impedance spectroscopy proved to be applicable even to this kind of material marked by considerable water content and exhibiting relatively high electric conductivity; so far it had been used only for materials of low conductivity. An aqueous environment inoculated with digested anaerobic sludge from a municipal wastewater treatment plant was selected for modeling anaerobic conditions. The relation was studied between cross-linking degree given by content of cross-linking agent (determined by impedance spectroscopy) and biodegradation degree under anaerobic conditions. It was confirmed that network density as given by quantity of added agent not only reduced breakdown degree but also slowed the course of the process. This fact is particularly obvious with cross-linking by means of glyoxal; network density is thus dependent on type of employed substance, which affect type and structure of created network. That not merely forms an obstacle during polymer swelling and dissolution but also prevents access of bacteria to source of metabolized organic carbon. 相似文献