全文获取类型
收费全文 | 489篇 |
免费 | 2篇 |
国内免费 | 8篇 |
专业分类
安全科学 | 8篇 |
废物处理 | 17篇 |
环保管理 | 45篇 |
综合类 | 126篇 |
基础理论 | 99篇 |
环境理论 | 1篇 |
污染及防治 | 143篇 |
评价与监测 | 33篇 |
社会与环境 | 23篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 7篇 |
2022年 | 6篇 |
2021年 | 21篇 |
2020年 | 12篇 |
2019年 | 7篇 |
2018年 | 21篇 |
2017年 | 21篇 |
2016年 | 24篇 |
2015年 | 16篇 |
2014年 | 18篇 |
2013年 | 43篇 |
2012年 | 32篇 |
2011年 | 40篇 |
2010年 | 15篇 |
2009年 | 25篇 |
2008年 | 25篇 |
2007年 | 27篇 |
2006年 | 27篇 |
2005年 | 14篇 |
2004年 | 16篇 |
2003年 | 17篇 |
2002年 | 7篇 |
2001年 | 10篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1990年 | 3篇 |
1988年 | 1篇 |
1983年 | 2篇 |
1979年 | 1篇 |
1975年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
1962年 | 1篇 |
1961年 | 2篇 |
1957年 | 2篇 |
1956年 | 2篇 |
1954年 | 1篇 |
排序方式: 共有499条查询结果,搜索用时 31 毫秒
41.
M. Gueri E.S. Guerra L.E. Gonzalez N.A. Martinez A.V. Olivares E. Rosero C. de Ville de Goyet 《Disasters》1983,7(3):174-179
A retrospective study of the effects of the Tumaco earthquake of 1979 shows a smaller number of deaths and injuries than in earthquakes of similar magnitude that have occurred elsewhere, which is probably related to the type of building. Most of the deaths were caused by a tsunami. Proportionally the mortality was higher in the 0 to 4 age group. Among the injured, most of the lesions were minor. Morbidity was higher in the over 45 years age group, and lower among the "under-fives." There was an evident need for a simple "disaster medical record card." Coordination among the different relief agencies could have been better. 相似文献
42.
Muniz P Danulat E Yannicelli B García-Alonso J Medina G Bícego MC 《Environment international》2004,29(8):1019-1028
As part of the first environmental assessment within Montevideo Harbour, in summer and winter of 1998, sediments samples were collected at eight locations to determine the spatial distribution of anthropogenic pollutants. Muddy sediments with high organic matter content dominate the study area. Heavy metal levels indicated that sediments were highly polluted with Zn (overall mean: 312+/-102 microg g(-1) dry sediment), Pb (85+/-31), Cu (89+/-25), Cr (162+/-62), and Hg (0.63+/-0.3) and moderately with Ni (30+/-2) and Ag (1.2+/-0.4). Depending on location and season, aliphatic hydrocarbons reached from 21 to 120 microg g(-1), while the unresolved complex mixture represented up to 76% of the total aliphatic fraction. Total PAH concentrations ranged from 1.56 to 90.44 microg g(-1); except at one location, petroleum derivatives were identified as main local source. The results pointed out that almost all the harbour area presented some substances that can cause adverse biological effects, especially in the inner region where all metals are above PEL levels. Principal components analysis confirmed that the inner harbour region is most severely affected by the pollutants and it was possible to differentiate three regions according to their environmental quality. 相似文献
43.
44.
Rachèl V. van Schendel G. C. Page-Christiaens Lean Beulen Catia M. Bilardo Marjon A. de Boer Audrey B. C. Coumans Brigitte H. Faas Irene M. van Langen Klaske D. Lichtenbelt Merel C. van Maarle Merryn V. E. Macville Dick Oepkes Eva Pajkrt Lidewij Henneman for the Dutch NIPT Consortium 《黑龙江环境通报》2016,36(12):1091-1098
45.
46.
Francesca Bardi Pien Bosschieter Joke Verheij Attie Go Monique Haak Mireille Bekker Esther Sikkel Audrey Coumans Eva Pajkrt Caterina Bilardo 《黑龙江环境通报》2020,40(2):197-205
Objectives
To give an overview of the genetic and structural abnormalities occurring in fetuses with nuchal translucency (NT) measurement exceeding the 95th percentile at first-trimester screening and to investigate which of these abnormalities would be missed if cell-free fetal DNA (cfDNA) were used as a first-tier screening test for chromosomal abnormalities.Methods
This is a national study including 1901 pregnancies with NT≥95th percentile referred to seven university hospitals in the Netherlands between 1 January 2010 and 1 January 2016. All cases with unknown pregnancy outcome were excluded. Results of detailed ultrasound examinations, karyotyping, genotyping, pregnancy and neonatal outcomes, investigation by a clinical geneticist and post-mortem investigations were collected.Results
In total, 821 (43%) pregnancies had at least one abnormality. The rate of abnormalities was 21% for fetuses with NT between 95th and 99th percentile and 62% for fetuses with NT≥99th percentile. Prevalence of single-gene disorders, submicroscopic, chromosomal and structural abnormalities was 2%, 2%, 30% and 9%, respectively.Conclusion
Although cfDNA is superior to the combined test, especially for the detection of trisomy 21, 34% of the congenital abnormalities occurring in fetuses with increased NT may remain undetected in the first trimester of pregnancy, unless cfDNA is used in combination with fetal sonographic assessment, including NT measurement. 相似文献47.
Mauro Mecozzi Demetria Cardarilli Eva Pietrantonio Marina Amici 《Chemistry and Ecology》2001,17(4):239-254
In this paper a method for the study of the qualitative similarity of extractable humic substance (EHS) in marine sediments based on the realisation of UV spectral library of EHS is described. the spectral library was built including the digitised spectra of humic substance extracted from several marine sediments (46 samples) and two samples of standard materials (lignin sulphonate and humic substance) in a Statistica data file. the data matrix was elaborated by means of different multivariate statistic techniques such as Cluster Analysis (CA), Principal Components Analysis (PCA) and the univariate technique Spectral Correlation Analysis (SCA). This approach allows us to show the contribution of different organic compounds (aromatic, lipid and acid) to the composition of EHS and moreover it evidences also the structural characteristics of EHS in terms of similarities in the qualitative composition of samples such as presence of terrestrial and/or vegetal contributions. the UV library is an objective tool to study the qualitative composition of EHS and it represents a complementary approach to the most common methods based on the application of spectroscopic (IR, 13CNMR), potentiometric and chromatographic techniques. 相似文献
48.
MarÍA JOSÉ Ruiz‐López Natalia Gañan José Antonio Godoy Ana Del Olmo Julian Garde Gerardo Espeso Astrid Vargas Fernando Martinez Eduardo R. S. Roldán Montserrat Gomendio 《Conservation biology》2012,26(6):1121-1129
The relation among inbreeding, heterozygosity, and fitness has been studied primarily among outbred populations, and little is known about these phenomena in endangered populations. Most researchers conclude that the relation between coefficient of inbreeding estimated from pedigrees and fitness traits (inbreeding‐fitness correlations) better reflects inbreeding depression than the relation between marker heterozygosity and fitness traits (heterozygosity‐fitness correlations). However, it has been suggested recently that heterozygosity‐fitness correlations should only be expected when inbreeding generates extensive identity disequilibrium (correlations in heterozygosity and homozygosity across loci throughout the genome). We tested this hypothesis in Mohor gazelle (Gazella dama mhorr) and Iberian lynx (Lynx pardinus). For Mohor gazelle, we calculated the inbreeding coefficient and measured heterozygosity at 17 microsatellite loci. For Iberian lynx, we measured heterozygosity at 36 microsatellite loci. In both species we estimated semen quality, a phenotypic trait directly related to fitness that is controlled by many loci and is affected by inbreeding depression. Both species showed evidence of extensive identity disequilibrium, and in both species heterozygosity was associated with semen quality. In the Iberian lynx the low proportion of normal sperm associated with low levels of heterozygosity was so extreme that it is likely to limit the fertility of males. In Mohor gazelle, although heterozygosity was associated with semen quality, inbreeding coefficient was not. This result suggests that when coefficient of inbreeding is calculated on the basis of a genealogy that begins after a long history of inbreeding, the coefficient of inbreeding fails to capture previous demographic information because it is a poor estimator of accumulated individual inbreeding. We conclude that among highly endangered species with extensive identity disequilibrium, examination of heterozygosity‐fitness correlations may be an effective way to detect inbreeding depression, whereas inbreeding‐fitness correlations may be poor indicators of inbreeding depression if the pedigree does not accurately reflect the history of inbreeding. Correlaciones Heterocigosidad‐ Adaptabilidad y Depresión Endogámica en Dos Especies de Mamíferos Críticamente en Peligro 相似文献
49.
50.