全文获取类型
收费全文 | 5218篇 |
免费 | 169篇 |
国内免费 | 195篇 |
专业分类
安全科学 | 183篇 |
废物处理 | 51篇 |
环保管理 | 1208篇 |
综合类 | 2288篇 |
基础理论 | 450篇 |
环境理论 | 19篇 |
污染及防治 | 384篇 |
评价与监测 | 780篇 |
社会与环境 | 198篇 |
灾害及防治 | 21篇 |
出版年
2024年 | 1篇 |
2023年 | 37篇 |
2022年 | 41篇 |
2021年 | 67篇 |
2020年 | 178篇 |
2019年 | 73篇 |
2018年 | 70篇 |
2017年 | 131篇 |
2016年 | 167篇 |
2015年 | 128篇 |
2014年 | 205篇 |
2013年 | 271篇 |
2012年 | 187篇 |
2011年 | 355篇 |
2010年 | 184篇 |
2009年 | 313篇 |
2008年 | 248篇 |
2007年 | 254篇 |
2006年 | 261篇 |
2005年 | 133篇 |
2004年 | 157篇 |
2003年 | 226篇 |
2002年 | 194篇 |
2001年 | 196篇 |
2000年 | 222篇 |
1999年 | 197篇 |
1998年 | 170篇 |
1997年 | 161篇 |
1996年 | 104篇 |
1995年 | 84篇 |
1994年 | 111篇 |
1993年 | 93篇 |
1992年 | 70篇 |
1991年 | 49篇 |
1990年 | 27篇 |
1989年 | 35篇 |
1988年 | 33篇 |
1987年 | 26篇 |
1986年 | 24篇 |
1985年 | 18篇 |
1984年 | 18篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1979年 | 2篇 |
1978年 | 12篇 |
1977年 | 5篇 |
1975年 | 1篇 |
1974年 | 3篇 |
排序方式: 共有5582条查询结果,搜索用时 15 毫秒
51.
环保产业——上海21世纪新的经济增长点 总被引:1,自引:0,他引:1
环境与经济协调发展已成为世界性主题,环境保护、绿色浪潮的呼声越来越高,许多国家都在瞄准这一全球性的环保大市场。尽管目前上海的环保产业还比较弱,但应当看到其发展的广阔前景和良好条件,只要方方面面重视环保产业的发展,环保产业必将成为上海21世纪新的经济增长点。该文从环保产业在经济发展中的作用谈起,展望了环保产业发展的市场前景,并就上海环保产业发展的主要方向作了较详细的阐述。 相似文献
52.
土壤中砷的原子荧光法测定 总被引:9,自引:0,他引:9
将土壤粉末均匀稳定地悬浮于0.15%~0.2%琼脂溶胶中,采用悬浮样品直接进样,氢化物发生—非色散原子荧光法,测定其砷含量。以柠檬酸—NaOH缓冲液控制试样pH4.7,测定As~(3+);以HCl、KI和抗坏血酸还原As~(5+)为As~(3+),测定总砷量;用差减法求得As~(5+)含量。方法应用于测定不同类型土壤时,相对标准偏差为1%~6%,回收率为85%~106%。 相似文献
53.
介绍了目前对环境样品中总汞及其各形态未的分析方法以及大气和水生生态系统中汞的研究进展,并指出,燃煤、汞齐法采金和人造水库等引起的环境汞污染问题以及汞在热带地区水生生态系统中的迁移转化规律等是目前的研究热点。 相似文献
54.
论新《刑法》的破坏环境资源保护罪 总被引:1,自引:0,他引:1
修订后的《中华人民共和国刑法》增加了“破坏环境资源保护罪”。对“破坏环境资源保护罪”的设立、认定以及刑事处罚等方面进行了分析,分析其对保护环境的作用以及存在的不足之处。 相似文献
55.
Dr. Michael J. McCormack Margaret E. Rylance William E. Mackenzie John Newton 《黑龙江环境通报》1990,10(4):253-255
The attitudes of 190 patients who had undergone chorionic villus sampling (CVS) were assessed by means of a questionnaire. One hundred and fifty-two patients replied of whom 68 (45 per cent) were referred because of increased maternal age and in the other 84 cases the indications included previous chromosomal abnormalities, fetal sexing, DNA analysis, and biochemical analysis. One hundred and twenty-two patients had a transcervical procedure, 24 had a transabdominal, and six patients required both procedures. One hundred and forty-one patients (93 per cent) reported CVS to be a satisfactory procedure, and the same percentage thought earlier diagnosis was beneficial. Thirty-nine patients (81 per cent) reported a better experience with CVS than with a previous amniocentesis. A majority of patients (93 per cent) wished a CVS in a future pregnancy and 137 patients (97 per cent) would accept a risk of miscarriage from the procedure of twice that quoted for amniocentesis (1 per cent). 相似文献
56.
Ellen Sidransky Susan H. Black Dawn M. Soenksen Shirley L. Jones Andrew D. Dorfmann Joseph D. Schulman MD 《黑龙江环境通报》1990,10(9):583-586
Chorionic villus sampling (CVS) with either transcervical catheters or transabdominal needles is a widely-accepted method for prenatal diagnosis. However, there exists a small subset of patients in whom sampling is difficult or impossible with either route because of individual anatomic variations. A new method of chorionic villus biopsy has been developed to circumvent these problems, utilizing transvaginal chorionic needle aspiration guided by an intravaginal ultrasound probe. This technique was performed successfully in 15 patients in whom villi could not be obtained by either of the conventional methods. This method now makes CVS possible in essentially all women regardless of their uterine anatomy or placental placement; it may also prove useful for very early chorionic sampling. 相似文献
57.
This paper reports results of an exploratory study of prenatal diagnosis patients who experienced voluntary terminations of pregnancy following the detection of an abnormality or spontaneous miscarriages. The 121 participants were part of the national collaborative Chorionic Villus Sampling and Amniocentesis Study. They completed semi-structured telephone interviews and mailed questionnaires at 1 month and 6 months after the pregnancy losses. Scores on the Profile of Mood States showed that mood levels improved significantly over time. However, there were some declines in loss-related support from partners and others. The persisting distress and difficulties of a minority highlight the variability in women's responses to pregnancy losses. Women who lost pregnancies later in gestation, showed the greatest mood disturbances at initial assessments, used professional mental health assistance after the loss, or reported less satisfactory loss-related support from significant others showed the greatest levels of mood disturbance at the six-month assessment. Follow-up contacts with patients who lose pregnancies should be used to inform women about the variation in possible grief reactions, to assess the extent of support the women are receiving from their partners and significant others, and to provide additional follow-up or referral of those experiencing the greatest distress. 相似文献
58.
Dr. C. Dawn DeLozier-Blanchet Eric Engel Philippe Extermann Béatrice Pastori 《黑龙江环境通报》1988,8(4):281-286
Cytogenetic study of chorionic villi sampled because of advanced maternal age revealed, after overnight culture, an apparently non-mosaic trisomy 7. Amniocentesis showed exclusively normal mitoses, and the pregnancy continued normally. One hundred mitoses from cord blood of the normal newborn revealed a non-mosaic 46,XX complement. No cells with a proven trisomy 7 were found in cultures from either of two biopsies of the morphologically normal placenta, but the peripheral biopsy showed in multiple cultures an abnormal clone: 47,XX, + 20,-2,-21, + t(2;21)(p13;q22). To our knowledge, this is the first case of non-mosaic trisomy 7 detected on CVS which has had follow-up studies of amniotic fluid, cord blood, and term placenta. 相似文献
59.
M. L. Smith O. L. Pellett M. M. J. Cass N. G. Kennaway N. R. M. Buist J. Buckmaster M. Golbus G. S. Spear J. A. Schneider 《黑龙江环境通报》1987,7(1):23-26
The prenatal diagnosis of cystinosis is currently based on the increased amount of free-cystine present in amniotic fluid cells. Amniocyte cultures must be grown for at least 2 weeks to obtain sufficient cells for such measurements. Thus, the diagnosis cannot be made until close to 20 weeks gestational age by this method. We report a case in which chorionic villi were used for direct cystine measurement resulting in the in utero diagnosis of cystinosis at 9 weeks gestational age. The diagnosis was confirmed by the study of cultured chorionic villus cells, and of the 10-week abortus. 相似文献
60.
The prenatal diagnosis of The Turner Syndrome is described at a menstrual age of 12 weeks. Detection of cystic hygroma was followed by vaginal chorionic villous sampling (CVS) which revealed a 45,X karyotype. Early documentation of fetal karyotype in the presence of a cystic hygroma is essential for accurate diagnosis and genetic counselling. 相似文献