全文获取类型
收费全文 | 30279篇 |
免费 | 278篇 |
国内免费 | 184篇 |
专业分类
安全科学 | 633篇 |
废物处理 | 1614篇 |
环保管理 | 4191篇 |
综合类 | 3961篇 |
基础理论 | 8759篇 |
环境理论 | 12篇 |
污染及防治 | 6607篇 |
评价与监测 | 2329篇 |
社会与环境 | 2488篇 |
灾害及防治 | 147篇 |
出版年
2023年 | 106篇 |
2022年 | 176篇 |
2021年 | 156篇 |
2020年 | 157篇 |
2019年 | 171篇 |
2018年 | 1795篇 |
2017年 | 1748篇 |
2016年 | 1658篇 |
2015年 | 491篇 |
2014年 | 612篇 |
2013年 | 1573篇 |
2012年 | 1152篇 |
2011年 | 2298篇 |
2010年 | 1552篇 |
2009年 | 1437篇 |
2008年 | 1844篇 |
2007年 | 2247篇 |
2006年 | 806篇 |
2005年 | 787篇 |
2004年 | 738篇 |
2003年 | 779篇 |
2002年 | 794篇 |
2001年 | 749篇 |
2000年 | 581篇 |
1999年 | 331篇 |
1998年 | 260篇 |
1997年 | 262篇 |
1996年 | 267篇 |
1995年 | 307篇 |
1994年 | 304篇 |
1993年 | 247篇 |
1992年 | 249篇 |
1991年 | 225篇 |
1990年 | 237篇 |
1989年 | 225篇 |
1988年 | 182篇 |
1987年 | 202篇 |
1986年 | 190篇 |
1985年 | 196篇 |
1984年 | 212篇 |
1983年 | 196篇 |
1982年 | 179篇 |
1981年 | 162篇 |
1980年 | 145篇 |
1979年 | 143篇 |
1978年 | 128篇 |
1977年 | 128篇 |
1976年 | 95篇 |
1974年 | 94篇 |
1973年 | 98篇 |
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
441.
442.
443.
444.
445.
Environmental managers at U.S. Department of Defense (DoD) installations overseas are faced with the challenge of managing contaminated sites at these installations with little information on the extent of contamination or the risk posed by the site. In this regard, DoD managers overseas encounter a situation quite similar to the situation faced by decision makers in the U.S. who are managing brownfields. Innovative site characterization and risk-based decision-making methods, which are currently being developed for expeditious application at brownfield sites in the U.S., may also be appropriate for application at overseas DoD sites. In this paper, the analytic hierarchy process (AHP) is used by DoD decision makers to evaluate and rank innovative site characterization technologies and risk-based decision-making and management methods, for use at installations in Korea. Results indicate that for sites with high potential risk the decision makers preferred site characterization technologies that produce data of high quality and a method that can be used to establish credible risk-based remediation goals. This study provides a framework for applying characterization technologies and risk management to poorly characterized contaminated sites in developing countries, where resources for remedial actions may be limited. 相似文献
446.
In this paper we describe the use of five-colour fluorescence in situ hybridization for prenatal diagnosis of aneuploidy using uncultured amniotic fluid cells. The analysis is based on ratio mixing of dual-labelled probes and digital imaging for the detection and visualization of five different probes specific for the five target chromosomes, 13, 18, 21, X, and Y. A retrospective blind analysis of 30 coded uncultured amniotic fluid samples correctly detected fetal sex and five trisomy 21 cases. Multicolour fluorescence in situ hybridization used in this way allows rapid and simultaneous detection of the most frequent aneuploidies. 相似文献
447.
Dr. Yash P. Agrawal Päivi Ylikangas Markku T. Parviainen Ilkka M. Penttilä 《黑龙江环境通报》1994,14(12):1141-1149
The histochemical measurement of urea-resistant alkaline phosphatase from maternal blood neutrophils is known to have a high detection rate for the prenatal detection of Down's syndrome pregnancies. However, because the histochemical method is laborious and subjective to use, it has not gained widespread acceptance in prenatal screening programmes. We present a simple and objective method for the measurement of urea-resistant alkaline phosphatase by flow cytometry. The method should allow the design of larger studies aimed at evaluating the role of neutrophil urea-resistant alkaline phosphatase in the prenatal screening for Down's syndrome. 相似文献
448.
Ultrasound examination at 12 weeks' gestation revealed severe generalised subcutaneous oedema in a pregnancy at risk for achondrogenesis type II. Transvaginal scanning confirmed the oedema and suggested abnormal limb development. The prenatal diagnosis was confirmed by X-ray examination after transvaginal termination. 相似文献
449.
William D. Boelter MD Beth Ann Burt Elaine B. Spector David R. Hinton Zdena Pavlova Atsuko Fujimoto 《黑龙江环境通报》1990,10(11):703-715
A pregnant woman with indeterminate Duchenne muscular dystrophy (DMD) carrier status, but with DMD diagnosed in her deceased brother (unavailable for study), presented for prenatal diagnosis, intending to continue the pregnancy only if proven unaffected with DMD with near absolute certainty. Creatine kinase (CK) assays to clarify carrier status were inconclusive. Male sex in the fetus was identified, but DNA restriction fragment length polymorphism (RFLP) analysis was not yet available to this centre to investigate the possible transmission of the DMD gene, and the pregnancy was terminated. Tissue histology and dystrophin protein analysis demonstrated the absence of DMD. In a situation with proven maternal carrier status, future fetal inheritance of the opposite maternal X chromosome would indicate the presence of DMD. However, maternal carrier status remained in doubt through a second pregnancy, even with RFLP studies, and was finally established when dystrophin analysis confirmed the presence of DMD in the second fetus. Histologic findings are presented, contrasting features in the two fetuses. The value of dystrophin analysis for establishing the diagnosis of fetal DMD, in this case proving maternal carrier status in a difficult situation, and for demonstrating DMD gene:RFLP haplotype relationships is illustrated. 相似文献
450.
A. Caruso A. Lanzone V. Bianchi M. Massidda M. P. Castelli A. M. Fulghesu Professor S. Mancuso 《黑龙江环境通报》1987,7(1):41-50
The efficacy of the insulin infusion pump (CSII) in pregnancy was examined in 12 diabetic patients and compared with intermittent insulin therapy (IIT). In patients poorly controlled on IIT constant and rapid equilibrium was achieved with CSII (mean of glucose levels: CSII versus IIT=84 versus 137 mg/dl; S.D. = 36 versus 63 mg/dl; mean amplitude of glycemic excursion (MAGE)=65 versus 112 mg/dl. In patients well controlled on IIT, CSII led to a reduction in the variation of glucose excursions (S.D.= 29 versus 36 mg/dl; MAGE=48 versus 76 mg/dl). CSII generally produced a reduction of 20–37 per cent of daily insulin dose (in three cases there was an increase of dose with the achievement of glycemic control). Furthermore in CSII treated-patients amniotic glucose, insulin and C-peptide concentrations werefound tobeinthenormalrange(22.1±10.1 mg/dl; 5.2±2.7μ/ml; 1.25±0.71 ng/ml, respectively). All infants were horn at or near-term, had no macrosomia or neonatal problems. It is concluded that CSII is a highly efficient way to achieve normal glucose levels in pregnancy, not only in type I, hut also in type II or gestational diabetes. 相似文献