全文获取类型
收费全文 | 184篇 |
免费 | 13篇 |
学科分类
环境安全 | 197篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 5篇 |
2019年 | 2篇 |
2018年 | 8篇 |
2017年 | 8篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 14篇 |
2012年 | 1篇 |
2011年 | 7篇 |
2010年 | 6篇 |
2009年 | 2篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 9篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 2篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1995年 | 21篇 |
1994年 | 11篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 2篇 |
1975年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有197条查询结果,搜索用时 0 毫秒
1.
Five cases of mosaicism for an isochromosome of 20q have been detected from a total of 50 000 cases analysed for prenatal diagnosis by amniocentesis. Karyotypes were designated mos 46,X_/46,X_,i(20q). In all cases, the abnormal cell line was detected in more than one primary culture, thus fulfilling the criterion for true (level III) mosaicism. Indications for prenatal diagnosis were parental anxiety (two cases), low maternal serum alpha-fetoprotein (AFP) (two cases), and high maternal serum AFP (one case). Level II ultrasounds on all five fetuses were normal, and the abnormal cell line was never detected in fetal blood and/or cord blood. All five pregnancies were continued and had normal outcomes, with birth weights ranging from 2.4 to 3.8 kg. The development of all five children has been normal, with the oldest child in the study now 4 years of age. We suggest that the abnormal cell line in each case was of extrafetal origin, and that this may be one of the more common examples of this phenomenon, occurring in approximately 1/10000 prenatal diagnoses. Mosaicism i(20q) may have been missed in the past because of the higher resolution necessary to detect this subtle change. 相似文献
2.
Stickler syndrome is an autosomal dominant disorder of the connective tissue which includes ocular and systemic manifestations. We report on a large kindred in which we were able to demonstrate very tight linkage between the disease and the type II collagen gene (COL2A1) (LOD score 3·91 at θ=0). In a family in which the father and one of his daughters were severely affected, DNA analysis from a chorionic villus sample demonstrated that the fetus possessed the normal allele of COL2A1. Thereafter a normal child was born. 相似文献
3.
Maya Thangavelu PhD Eugene Pergament Rafael Espinosa Iii Stefan K. Bohlander 《黑龙江环境通报》1994,14(7):583-588
We characterized by microdissection and fluorescence in situ hybridization (FISH) two marker chromosomes: (1) a de novo, acrocentric marker chromosome detected in 88 per cent of the amniotic fluid cells of one of two physically and developmentally normal twins; and (2) a metacentric marker chromosome present in a phenotypically normal female. Analysis of FISH probes developed from the marker chromosomes indicated that the marker chromosomes in cases 1 and 2 were del(14)(q11) and a derivative chromosome from a Robertsonian translocation, respectively. Microdissection in combination with FISH may prove to be a valuable technique in determining the chromosomal origin of de novo marker chromosomes and unbalanced structural rearrangements detected during prenatal diagnosis. 相似文献
4.
Possibilities for greater variation in landscaping during the reclamation of derelict colliery spoil heaps and the potential of a regional approach to the survey of revegetation problems are introduced. A survey method for assessing plant growth problems is described which incorporates rapid measurement of physical and chemical constraints to plant growth and which uses bioassay trials as an index of plant growth potential. The use of the survey method on 34 closed and disused sites in the Barnsley and South Yorkshire areas of the National Coal Board is outlined and suggestions for the incorporation of such data in recommendations for the reclamation of individual sites are made. 相似文献
5.
Towards a politics of disaster response: presidential disaster instructions in China, 1998–2012 下载免费PDF全文
China's disaster management system contains no law‐based presidential disaster declarations; however, the national leader's instructions (pishi in Chinese) play a similar role to disaster declarations, which increase the intensity of disaster relief. This raises the question of what affects presidential disaster instructions within an authoritarian regime. This research shows that China's disaster politics depend on a crisis threshold system for operation and that the public and social features of disasters are at the core of this system. China's political cycle has no significant impact on disaster politics. A change in the emergency management system has a significant bearing on presidential disaster instructions, reflecting the strong influence of the concept of rule of law and benefiting the sustainable development of the emergency management system. In terms of disaster politics research, unlocking the black box of China's disaster politics and increasing the number of comparative political studies will benefit the development of empirical and theoretical study. 相似文献
6.
Ulrich Harréus MD PhD Philipp Baumeister Norbert Kleinsasser Maximilian Reiter Beatrice Bachmeier Christoph Matthias 《毒物与环境化学》2013,95(2):205-214
The etiology of salivary gland malignancies still remains unclear. Metal compounds are of special interest since they show ubiquitous presence in the environment, are present in many working places, and are accepted (co-)carcinogens in some other malignancies. Metals enter the body as xenobiotics by inhalation or ingestion. This study investigated the genotoxic potential of sodium dichromate (Na2Cr2O7), nickel sulfate (NiSO4), cadmium sulfate (CdSO4) and zinc chloride (ZnCl2) on human salivary gland cells and lymphocytes. Macroscopically healthy tissue of salivary glands was harvested from 46 patients during surgery and isolated to single cells by enzymatic digestion. The cells were incubated with Na2Cr2O7, NiSO4, CdSO4 or ZnCl2. Na2Cr2O7 was also incubated in combination with the other metal compounds listed. Carcinogenic and co-carcinogenic effects of cadmium were tested by incubation with Na2Cr2O7 and consecutive repair intervals. DNA damage and repair were evaluated by the Comet assay, determining DNA-strand breaks. The extent of damage was quantified using a digital analysis system. Na2Cr2O7 produced significantly enhanced DNA-strand breaks in human salivary gland tissue and lymphocytes. All other metal compounds exerted no damaging effect on both cell types. Co-incubation of Na2Cr2O7 with the other metals revealed a significant additive effect only for CdSO4. Specific analysis of the influence of cadmium showed a reduction of DNA-repair after Na2Cr2O7-induced strand breaks in salivary gland cells. This study provides evidence that exposure to distinct metals may significantly contribute to malignant salivary gland tumors. In consequence, further studies as epidemiological and toxicological data are warranted to determine the role of distinct metals as potential (co-) carcinogens. 相似文献
7.
Christian Sonne PhD DVM VMD MVSc Rossana Bossi Rune Dietz Pall S. Leifsson Frank F. Rigét Erik W. Born 《毒物与环境化学》2013,95(2):275-283
In this study, residual concentrations of chlorpyrifos (CPF) were determined in feed (40) and fodder (25) samples collected from various locations of Tarai region of Uttarakhand. For extracting residues, liquid–liquid partition followed by alumina column clean up was used and the detection and quantification of residues was undertaken with the help of high-performance liquid chromatography using C18 column and diode array detector at 220?nm. Of the total 40 feed samples analyzed, 7 (17.5%) samples were found positive for CPF with the mean residual concentration of 0.058?µg?g?1; while out of 25 fodder samples, CPF residues were detected in a single (4%) sample with residual concentration of 0.39?µg?g?1. However, none of the feed or fodder samples contained CPF residues above the prescribed limit. 相似文献
8.
Christine Willekes Frans J. M. E. Roumen MD PhD Anne-Marie W. van Elsacker-Niele Harro T. Weiland Christl Vermey-Keers Johan H. J. M. van Krieken Christine E. M. de Die-Smulders Guus J. H. Hamers Gerrie P. M. Vaes-Peters 《黑龙江环境通报》1994,14(3):181-185
In a case of hydrops fetalis, serological examination showed a recent maternal human parvovirus B19 infection. Amniocentesis revealed a unique unbalanced translocation between chromosomes 3 and 11 of the fetus. The mother proved to have a balanced reciprocal translocation between chromosomes 3 and 11. A grossly macerated hydropic male fetus was delivered with a flat nose and low implanted deformed ears. Histopathological examination revealed nuclear inclusion bodies in fetal erythroid cells, confirming human parvovirus B19 infection. Parvovirus B19 DNA was demonstrated by in situ hybridization in the nuclei of heart muscle cells. Our finding of two different disorders in one case illustrates the importance of a complete evaluation of every case of hydrops fetalis, especially concerning counselling on the outcome of future pregnancies. The human parvovirus B19 infection will not recur due to the acquired immunity of the mother, whereas the balanced reciprocal translocation will endanger future pregnancies. 相似文献
9.
Joanna Burger Jessica Sanchez J. Whitfield Gibbons Jeanine Ondrof Robert Ramos Michael J. McMahon Karen F. Gaines Christine Lord Marie Fulmer Michael Gochfeld 《Environmental monitoring and assessment》1999,57(2):195-211
Although considerable attention is devoted to environmental monitoring and assessment with respect to both pollutants and the status of particular plant or animal populations, less attention is devoted to assessing people's attitudes about the relative importance of ecological resources. In this paper we examine the attitudes and perceptions about ecological resources of people living around the Department of Energy's Savannah River Site (SRS), in South Carolina. Our overall hypothesis is that people who are directly affected by the possible outcomes and consequences of a particular hazard (i.e., those people employed at SRS) will undervalue the risks and overvalue the potential benefits from future land uses that favor continued site activity, compared to people who live near but are not employed at SRS. We interviewed 286 people attending the Aiken Trials horse show on 14 March 1997. There were few gender differences, although men hunted and fished more than women, women ranked three environmental concerns as more severe than did men, and women were more concerned about the effect of SRS on property values. Maintenance of SRS as a National Environmental Research Park ranked first as a future land use; nuclear production ranked second, followed by hunting and hiking. Only residential development ranked very low as a future land use. There were many differences as a function of employment history at SRS: 1) people who work at SRS think that the federal government should spend funds to clean up all nuclear facilities, and they think less money should be spent on other environmental problems than did non-employees, 2) people who work at SRS ranked continued current uses of SRS higher than did people who never worked at SRS, and 3) people who work at SRS are less concerned about the storage of nuclear material or accidents at the site than are people who never worked at the site. 相似文献
10.
Yates K Davies I Webster L Pollard P Lawton L Moffat C 《Journal of environmental monitoring : JEM》2007,9(10):1116-1121
Silicone rubber sheeting can be used as a passive sampling device for hydrophobic organic contaminants in the environment to determine the available concentrations in water and sediments. Reliable sampler-water partition coefficients are required to determine the sampling rates and the dissolved contaminant concentrations in water and in sediment pore water. Log partition coefficients (logK(sr,w)) for silicone rubber-water have been estimated for 32 polycyclic aromatic hydrocarbons (PAHs), 2 deuterated PAH analogues and 32 chlorobiphenyls (CBs) using the cosolvent method, with methanol as cosolvent. Strong linear relationships were found with literature values for the corresponding log octanol-water partition coefficients (logK(ow)) for both CBs and PAHs, confirming that partitioning into the silicone rubber is strongly determined by the hydrophobicity of the compounds, which suggests logK(ow) is a good predictor of logK(sr,w) and that absorption is the main mechanism for accumulation of analytes into the silicone rubber polymer. 相似文献