全文获取类型
收费全文 | 4145篇 |
免费 | 34篇 |
国内免费 | 18篇 |
专业分类
安全科学 | 47篇 |
废物处理 | 265篇 |
环保管理 | 264篇 |
综合类 | 665篇 |
基础理论 | 838篇 |
环境理论 | 4篇 |
污染及防治 | 1471篇 |
评价与监测 | 385篇 |
社会与环境 | 249篇 |
灾害及防治 | 9篇 |
出版年
2023年 | 48篇 |
2022年 | 127篇 |
2021年 | 130篇 |
2020年 | 49篇 |
2019年 | 55篇 |
2018年 | 150篇 |
2017年 | 108篇 |
2016年 | 215篇 |
2015年 | 112篇 |
2014年 | 231篇 |
2013年 | 398篇 |
2012年 | 256篇 |
2011年 | 248篇 |
2010年 | 191篇 |
2009年 | 152篇 |
2008年 | 236篇 |
2007年 | 234篇 |
2006年 | 215篇 |
2005年 | 152篇 |
2004年 | 121篇 |
2003年 | 107篇 |
2002年 | 92篇 |
2001年 | 60篇 |
2000年 | 44篇 |
1999年 | 34篇 |
1998年 | 13篇 |
1997年 | 13篇 |
1996年 | 8篇 |
1995年 | 28篇 |
1994年 | 21篇 |
1993年 | 15篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 11篇 |
1985年 | 7篇 |
1967年 | 7篇 |
1966年 | 11篇 |
1965年 | 16篇 |
1964年 | 28篇 |
1963年 | 12篇 |
1962年 | 17篇 |
1961年 | 11篇 |
1960年 | 9篇 |
1959年 | 26篇 |
1958年 | 25篇 |
1957年 | 17篇 |
1956年 | 13篇 |
1955年 | 18篇 |
1954年 | 7篇 |
排序方式: 共有4197条查询结果,搜索用时 15 毫秒
31.
Silva Marcio Roberto Ferreira Fernando César Maranhão Adriana Gonçalves Lanzarini Natália Maria de Carvalho Castro Karina Neboo Miagostovich Marize Pereira 《Food and environmental virology》2021,13(4):528-534
Food and Environmental Virology - Enteric viruses have been described as important contaminants in fresh and ready-to-eat foods such as sandwiches, deli meat and dairy products. This is a... 相似文献
32.
33.
Mr. M. T. Rebello G. Hackett J. Smith F. E. Loeffler S. Robson N. Maclachlan R. W. Beard C. H. Rodeck R. Williamson D. V. Coleman C. Williams 《黑龙江环境通报》1991,11(1):41-46
Ten-ml samples of amniotic fluid were taken from pregnancies being terminated at 8–14 weeks' gestation. DNA was extracted from the amniotic cells by sequential centrifugation and analysed using the polymerase chain reaction (PCR). Fifteen samples were analysed for evidence of maternal contamination using Mfd5 oligo-nucleotide primers for repeat polymorphisms. Ten amniotic fluid samples were tested for the Delta-F508 deletion characteristic of cystic fibrosis to demonstrate a diagnostic application for the technique. In each case, DNA extracted from fetal tissue from the same pregnancy was included in the controls. In 14 of the 15 cases tested with the Mfd5 primers, both the amniotic fluid DNA and the fetal DNA showed no evidence of contaminating DNA. In one case, neither the amniotic fluid cells nor the fetal cells yielded results. In nine of the ten cases tested with the Delta-F508 primers, the amniotic fluid cell DNA provided accurate information about the genetic status of the fetus; in the tenth, the fetal DNA failed to amplify. The results indicate that adequate DNA can be extracted from amniotic fluid from 8 weeks' gestation onward and these samples are suitable for prenatal diagnosis using PCR. 相似文献
34.
Adánez-Rubio Iñaki Pérez-Astray Antón Abad Alberto Gayán Pilar De Diego Luis F. Adánez Juan 《Mitigation and Adaptation Strategies for Global Change》2019,24(7):1293-1306
Mitigation and Adaptation Strategies for Global Change - Bioenergy with carbon dioxide (CO2) capture and storage (BECCS) technologies represent an interesting option to reach negative carbon... 相似文献
35.
Mr Selwyn H. Roberts Elizabeth Little Merle Vaughan Michael R. Creasy Anthony Jones Teyrnon G. Powell Andrew J. Dawson 《黑龙江环境通报》1993,13(10):971-975
A woman in the 32nd week of pregnancy was referred for investigation because of fetal abnormalities, including an abdominal wall defect, detected by ultrasonography. In view of the increased risk of chromosome abnormality, amniocentesis was performed to enable informed decisions about the management of the pregnancy and delivery to be taken. Cells from the liquor were inoculated into standard lymphocyte culture medium and incubated for 72 h. Slides with a high mitotic index and good quality metaphases, comparable to those from a blood culture, were obtained after harvesting. Cytogenetic analysis showed the karyotype to be 46,XY,—14,+t(13ql4q), which is consistent with Patau's syndrome. This technique appears to be an option for rapid karyotyping in cases of abdominal wall defect, where a chromosomal abnormality is suspected. 相似文献
36.
37.
Enrique Castelán 《Ambio-人类环境杂志》2003,32(2):124-129
引言 墨西哥城大都市区(MCMA)位于被称作"墨西哥谷(Valle deMexico)"的天然围合的盆地里,海拔2240m.它下辖联邦区和墨西哥州的34个自治市.墨西哥城是墨西哥的首都,位于联邦区(DistritoFederal,DF),四面环山,海拔高度超过5000m.墨西哥州是墨西哥人口最稠密的地区(据报道有1300万居民),人口仅次于它的是墨西哥城,大约有860万人[1]. 相似文献
38.
Tamás Marton Júlia Hajdú Csaba Papp Péter Patkós Ervin Hruby Zoltán Papp 《黑龙江环境通报》2001,21(6):452-456
The present study describes an association between adverse outcome in the twin-to-twin transfusion syndrome (TTTS) and pulmonary stenosis or reactive right ventricular hypertrophy. Six discordant monozygotic twin pregnancies with TTTS are described. Ventricular hypertrophy and atrioventricular valvular regurgitation occurred in all the recipient twins with pulmonary valvular stenosis in three cases and infundibular stenosis in one case. The recipient twin in one pair and both twins in another pregnancy died as a consequence of immaturity but the remaining twins all survived. Surgical intervention was required in one baby for valvular pulmonary stenosis. Our observations suggest that elevated blood pressure in the transfusion recipient may play an important role in pathogenesis. We hypothesise that both pulmonary stenosis and right chamber hypertrophy are secondary to hemodynamic changes. Although we have found valvular pulmonary stenosis in three recipients and infundibular stenosis in only one, this (obstruction to outflow) could be due to right chamber hypertrophy. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
39.
The plant surface is the substrate upon which herbivorous insects and natural enemies meet and thus represents the stage for
interactions between the three trophic levels. Plant surfaces are covered by an epicuticular wax layer which is highly variable
depending on species, cultivar or plant part. Differences in wax chemistry may modulate ecological interactions. We explored
whether caterpillars of Spodoptera frugiperda, when walking over a plant surface, leave a chemical trail (kairomones) that can be detected by the parasitoid Cotesia marginiventris. Chemistry and micromorphology of cuticular waxes of two barley eceriferum wax mutants (cer-za.126, cer-yp.949) and wild-type cv. Bonus (wt) were assessed. The plants were then used to investigate potential surface effects on
the detectability of caterpillar kairomones. Here we provide evidence that C. marginiventris responds to chemical footprints of its host. Parasitoids were able to detect the kairomone on wild-type plants and on both
cer mutants but the response to cer-yp.949 (reduced wax, high aldehyde fraction) was less pronounced. Experiments with caterpillar-treated wt and mutant leaves
offered simultaneously, confirmed this observation: no difference in wasp response was found when wt was tested against cer-za.126 (reduced wax, wt-like chemical composition) but wt was significantly more attractive than cer-yp.949. This demonstrates for the first time that the wax layer can modulate the detectability of host kairomones. 相似文献
40.