全文获取类型
收费全文 | 16661篇 |
免费 | 179篇 |
国内免费 | 143篇 |
专业分类
安全科学 | 463篇 |
废物处理 | 636篇 |
环保管理 | 2363篇 |
综合类 | 2612篇 |
基础理论 | 4540篇 |
环境理论 | 6篇 |
污染及防治 | 4362篇 |
评价与监测 | 1026篇 |
社会与环境 | 860篇 |
灾害及防治 | 115篇 |
出版年
2022年 | 117篇 |
2021年 | 137篇 |
2020年 | 112篇 |
2019年 | 153篇 |
2018年 | 231篇 |
2017年 | 229篇 |
2016年 | 366篇 |
2015年 | 249篇 |
2014年 | 371篇 |
2013年 | 1294篇 |
2012年 | 452篇 |
2011年 | 659篇 |
2010年 | 556篇 |
2009年 | 532篇 |
2008年 | 702篇 |
2007年 | 706篇 |
2006年 | 669篇 |
2005年 | 525篇 |
2004年 | 594篇 |
2003年 | 527篇 |
2002年 | 490篇 |
2001年 | 709篇 |
2000年 | 474篇 |
1999年 | 289篇 |
1998年 | 246篇 |
1997年 | 220篇 |
1996年 | 234篇 |
1995年 | 252篇 |
1994年 | 273篇 |
1993年 | 221篇 |
1992年 | 253篇 |
1991年 | 227篇 |
1990年 | 256篇 |
1989年 | 238篇 |
1988年 | 194篇 |
1987年 | 176篇 |
1986年 | 159篇 |
1985年 | 167篇 |
1984年 | 196篇 |
1983年 | 182篇 |
1982年 | 186篇 |
1981年 | 180篇 |
1980年 | 137篇 |
1979年 | 155篇 |
1978年 | 131篇 |
1977年 | 117篇 |
1975年 | 118篇 |
1974年 | 116篇 |
1973年 | 110篇 |
1972年 | 134篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
521.
We present a remarkable chain of events in which percutaneous umbilical cord sampling was performed in an attempt to clarify a situation of possible fetal sex chromosome mosaicism in an amniotic fluid culture and led to the discovery that the mother herself had a 45,X/46,XX/ 47.XXX chromosome constitution. This may have simply represented the chance concurrence of pseudo-mosaicism in the amniotic fluid culture of a woman with an abnormal sex chromosome constitution, but it is also possible that the 45,X colony was maternal in origin. Although clearly a most unusual circumstance, the possibility should be kept in mind when termination of a pregnancy is being considered because of apparent mosaicism in a prenatal diagnostic study. 相似文献
522.
We report relatively high citrulline concentration in amniotic fluid of a citrullinemic fetus suggesting that prenatal detection of this condition could be done on this basis in conjunction with a direct or an indirect determination of argininosuccinate synthetase activity in amniotic fluid cells. 相似文献
523.
Routine ultrasound examination at 30 weeks gestation revealed an intrapulmonary cystic mass in an otherwise normal fetus. Following delivery at term, the diagnosis of congenital cystic adenomatoid malformation of the right lung was confirmed, and an elective right middle lobectomy successfully performed at nine days of age. 相似文献
524.
D. Costa A. Borrell E. Margarit A. Carrió A. Soler I. Balmes X. Estivill A. Fortuny 《黑龙江环境通报》1995,15(2):141-148
Fluid from pleural effusion (n=2) and cystic hygroma (n=7) was obtained from eight fetuses, between 13 and 32 weeks of pregnancy at the time when a conventional prenatal diagnosis procedure was carried out. As these fluids contain lymphocytes, they were processed like peripheral blood. A karyotype was obtained in 4 days in both cases of pleural effusion and in four out of seven samples of cystic hygroma. An abnormal karyotype was detected in three of the four samples of cystic hygroma: two trisomies 21 and a monosomy X. Different parameters were evaluated in order to predict the feasibility of obtaining a cytogenetic diagnosis. Our data showed that if the amount of fluid obtained was ⩾4 ml and the initial lymphocyte count (ILC) was >0.2 × 106 cells/ml, a cytogenetic diagnosis was possible from an initial concentration of cultured lymphocytes )ICCL) of >0.06 × 106 cells/ml. 相似文献
525.
Val A. Catanzarite MD Ph.D. David B. Schrimmer Cynthia Maida Art Mendoza 《黑龙江环境通报》1995,15(3):229-235
The sinusoidal fetal heart rate pattern has been described in association with severe fetal anaemia, with fetal hypoxaemia, and with the administration of parenteral narcotics. Here, we report a case of decreased fetal movement in which a sinusoidal tracing was recorded. The sonographic diagnosis of a massive fetal intracranial haemorrhage was made. A non-interventive approach was taken and the fetus died soon after in utero. We review 28 previous cases in which the prenatal sonographic diagnosis of fetal intracranial haemorrhage was made, including the underlying maternal and fetal factors and neonatal outcomes. We propose that the sinusoidal tracing in this case was due to the intracranial bleed and suggest that fetal intracranial haemorrhage be considered in the sonographic evaluation of the fetus with a sinusoidal pattern. 相似文献
526.
Mary C. Phelan Ph.D. Robert A. Saul Thompson A. Gailey Jr Steven A. Skinner 《黑龙江环境通报》1995,15(3):274-277
Mosaicism for the Wolf-Hirschhorn syndrome, del(4)(p16), is extremely rare and has not been reported in association with a numerical chromosome abnormality. We report the prenatal diagnosis of mosaic del(4)(p16) and non-mosaic trisomy 21 in a 16-week female fetus. The pregnancy ended in spontaneous abortion at 34 weeks secondary to fetal demise. The fetus had features of both 4p – and trisomy 21. 相似文献
527.
528.
Bushra Waheed Faisal I. Khan Brian Veitch Kelly Hawboldt 《Journal of Cleaner Production》2011,19(6-7):720-732
Evaluation of sustainability in various facets of life is gaining increasing importance. Traditionally, different multi-criteria decision-making methods have been used for sustainability assessment. “Sustainability” can be a qualitative concept, and as such several researchers have attempted fuzzy logic for the quantitative assessment of sustainability. This paper outlines a new evaluation model based on fuzzy multi-criteria decision-making. The model is tested for sustainability assessment of higher education institutions (HEIs). It is based on a driving force–pressure–state–exposure–effect–action (DPSEEA) framework and is called uncertainty-based DPSEEA-Sustainability index Model (uD-SiM). The uD-SiM is a causality-based model in which the sustainability index is an outcome of nonlinear impacts of sustainability indicators in different stages of DPSEEA. The percent contribution of driving forces on the sustainability index of HEI is investigated using sensitivity analysis. The study reveals that education in sustainability and global and local research trends are the major driving forces for achieving sustainability in HEI, followed by financial and economic growth rate, social equity, energy requirements rate, and institutional enhancement, in descending order. The results of uD-SiM were found to be more realistic and rational than our earlier proposed approach, D-SiM. 相似文献
529.
530.
Cena LG Keren N Li W Carriquiry AL Pawlovich MD Freeman SA 《Journal of Safety Research》2011,42(4):241-252