全文获取类型
收费全文 | 31239篇 |
免费 | 355篇 |
国内免费 | 246篇 |
专业分类
安全科学 | 903篇 |
废物处理 | 1132篇 |
环保管理 | 4600篇 |
综合类 | 4773篇 |
基础理论 | 8881篇 |
环境理论 | 21篇 |
污染及防治 | 8157篇 |
评价与监测 | 1864篇 |
社会与环境 | 1300篇 |
灾害及防治 | 209篇 |
出版年
2022年 | 193篇 |
2021年 | 195篇 |
2019年 | 232篇 |
2018年 | 407篇 |
2017年 | 404篇 |
2016年 | 594篇 |
2015年 | 515篇 |
2014年 | 709篇 |
2013年 | 2381篇 |
2012年 | 894篇 |
2011年 | 1316篇 |
2010年 | 1092篇 |
2009年 | 1079篇 |
2008年 | 1313篇 |
2007年 | 1411篇 |
2006年 | 1262篇 |
2005年 | 1070篇 |
2004年 | 1047篇 |
2003年 | 1003篇 |
2002年 | 1002篇 |
2001年 | 1258篇 |
2000年 | 883篇 |
1999年 | 570篇 |
1998年 | 461篇 |
1997年 | 460篇 |
1996年 | 469篇 |
1995年 | 507篇 |
1994年 | 461篇 |
1993年 | 415篇 |
1992年 | 434篇 |
1991年 | 392篇 |
1990年 | 391篇 |
1989年 | 431篇 |
1988年 | 367篇 |
1987年 | 315篇 |
1986年 | 291篇 |
1985年 | 327篇 |
1984年 | 324篇 |
1983年 | 349篇 |
1982年 | 353篇 |
1981年 | 304篇 |
1980年 | 263篇 |
1979年 | 305篇 |
1978年 | 253篇 |
1977年 | 213篇 |
1976年 | 216篇 |
1975年 | 195篇 |
1974年 | 180篇 |
1973年 | 179篇 |
1972年 | 202篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
J. Altenburger Th. Dielacher P. Eder H. Ferner M. Fegerl J. Fresner O. Gelinek A. Kogler J. Jantschgi M. Nussbaumer B. Russegger H. Schnitzer K. Schauer B. Sebesta J. Seiler F. Sprenger H. Widenmeyer 《Journal of Cleaner Production》1994,2(3-4)
The paper focuses upon the organization of a federal state-funded pollution prevention project in the Styrian industry. The project includes 13 companies from the textile, pulp and paper, machine building, wood working and printed circuit board manufacturing industries, covering most of the sectors and sizes in the Styrian industry. It started in January 1994 and will last for one year. It will demonstrate the possibilities of pollution prevention and the need for further research work. This project will make use of the methods and tools that were refined in the Austrian Prepare project. As a first step, a systematic balance of all the inputs and outputs of a company is made, after which the weak points and inefficiencies of material and energy use are identified and the options for improvements, both economical and ecological, are defined. Consequently, modifications in products and production lead to a situation with less waste and emissions. The preliminary lessons from these projects are presented: as a rule, the utilities (consumption of process materials and water, cleaning, energy, preparatory and finishing steps) are treated as black boxes and usually represent a considerable optimization potential. In these areas especially there is usually a lack of information and coordination as well as a need for a systematic and comprehensive approach. Leadership in the company and creative consultants are needed for starting lasting successful pollution prevention projects. 相似文献
992.
993.
994.
995.
M. Kunter L. Jaenicke J. Heinze W. Jaenicke H. Meinhardt 《Die Naturwissenschaften》1994,81(11):513-517
996.
V. Cacheux G. Tachdjian L. Druart J. F. Oury S. Sérero P. Blot C. Nessmann 《黑龙江环境通报》1994,14(2):79-86
The major aneuploidies diagnosed prenatally involve the autosomes 13, 18, and 21, and sex chromosomes. Fluorescence in situ hybridization (FISH) allows rapid analysis of chromosome copy number in interphase cells. This prospective study evaluated the use of four commercially available centromeric DNA probes (DXZ1, DYZ1, D18Z1, and D13Z1/D21Z1) for direct analysis of uncultured amniocytes. One hundred and sixteen amniotic fluid samples were analysed by FISH and standard cytogenetics. This evaluation demonstrated that FISH with, X, Y, and 18 alpha satellite DNA probes could accurately and rapidly detect aneuploidies involving these chromosomes and could be used in any prenatal clinical laboratory. In contrast, the 13/21 alpha satellite DNA probe hybridizing both chromosomes 13 and 21 was unreliable for prenatal diagnosis in uncultured amniocytes. 相似文献
997.
R. G. Tiessen A. M. W. van Elsacker-Niele Chr. Vermeij-Keers D. Oepkes J. van Roosmalen M. C. B. Gorsira 《黑龙江环境通报》1994,14(3):173-176
A fetus with multiple structural defects was seen at prenatal ultrasound examination. After termination of the pregnancy a bilateral cleft lip, alveolus, and palate; micrognathia; and webbed joints were seen. Fetal tissues showed indications of infection, intranuclear inclusion bodies, chronic stress, haemolysis, arterial wall damage, and profuse haemorrhage. Parvovirus B19 DNA was detected in fetal tissues by dot hybridization after polymerase chain reaction. The possibility of parvovirus B19 infection leading to congenital malformations is discussed. 相似文献
998.
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
999.
Amniocentesis at 17 weeks' gestation revealed a mosaic karyotype—46,XX/46,XX, — 14,+dic(14)(p11). No abnormalities were detected on ultrasound. Growth and placentation were normal. The fetus was examined after termination of pregnancy and micrognathia and pulmonary hyperlobation were the only abnormalities detected. Several tissues were set up for cytogenetics, including fetal skin, kidney, ovary, and placenta. The diagnosis was confirmed by these studies. The level of mosaicism varied between tissues, with the trisomy 14 cell line highest in amniotic fluid. 相似文献
1000.
This study provides data on the incidence of fetal trisomies 21, 18, and 13 at 9–14 weeks' gestation in women aged 35–45 years and estimates of maternal age-specific risks in women aged 20–45 years. Our data from 5814 singleton pregnancies undergoing first-trimester karyotyping for the sole indication of maternal age ⩾ 35 years were combined with those from two previous reports and the incidence of the trisomies was calculated from a total of 15 793 pregnancies. Comparison of incidences at 9–14 weeks' gestation with published data at 15–20 weeks' gestation and in livebirths demonstrated that at birth the maternal age-specific incidence of trisomy 21 is 33 per cent lower than at 15–20 weeks' gestation and 54 per cent lower than at 9–14 weeks' gestation. Furthermore, the relative frequency of trisomies 18 and 13 decreases from 30 per cent at 9–14 weeks to 22 per cent at 15–20 weeks and 14 per cent at birth. 相似文献