全文获取类型
收费全文 | 585篇 |
免费 | 118篇 |
国内免费 | 213篇 |
专业分类
安全科学 | 55篇 |
废物处理 | 30篇 |
环保管理 | 38篇 |
综合类 | 492篇 |
基础理论 | 149篇 |
污染及防治 | 82篇 |
评价与监测 | 54篇 |
社会与环境 | 9篇 |
灾害及防治 | 7篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 11篇 |
2021年 | 15篇 |
2020年 | 16篇 |
2019年 | 19篇 |
2018年 | 67篇 |
2017年 | 29篇 |
2016年 | 31篇 |
2015年 | 28篇 |
2014年 | 43篇 |
2013年 | 63篇 |
2012年 | 37篇 |
2011年 | 43篇 |
2010年 | 37篇 |
2009年 | 36篇 |
2008年 | 27篇 |
2007年 | 38篇 |
2006年 | 44篇 |
2005年 | 30篇 |
2004年 | 29篇 |
2003年 | 30篇 |
2002年 | 34篇 |
2001年 | 27篇 |
2000年 | 64篇 |
1999年 | 16篇 |
1998年 | 8篇 |
1997年 | 15篇 |
1996年 | 14篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1983年 | 7篇 |
1982年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有916条查询结果,搜索用时 15 毫秒
841.
目的 建立黄孢原毛平革菌与10、50、100mg/L碱性紫5BN的共培养体系,研究菌种和培养条件对脱色降解效果的影响。方法 采用分光光度法测定培养液最大吸收波长处吸光度的改变,确定染料的脱色率及降解率。结果 (1)OGC101菌株的降解能力明显强于BKM-F-1767菌株,培养液最大吸收波长向短波方向移动,说明染料的N-去甲基化和降解中间物的形成;(2)琥珀酸钠缓冲液、04mM藜芦醇(VA)、浅层静置培养的参数组合较佳;(3)共培养30d后,各样品的脱色降解率为54%-98%;(4)染料浓度与脱色降解效应的相关性,因菌种而异。 相似文献
842.
843.
S.?AlbonettiEmail author S.?Blasioli M.?Bugani C.?Lehaut-Burnouf S.?Augustine E.?Roncari F.?Trifirò 《Environmental Chemistry Letters》2003,1(3):197-200
The aim of the plesent investigation was to study the effect of SiO2 addition on the thermal deactivation of V2O5/WO3/TiO2 catalysts used for NOx pollution abatement. The results suggest that the degradation of the catalytic properties is strongly correlated to the structural ageing which is, in turn, mainly related to the anatase–rutile phase transformation and to the WO3 phase segregation. The addition of SiO2 strongly influences the temperature at which these phenomena occur. In fact, it was found that the introduction of this oxide stabilizes the material, retarding the collapse of surface area, and increases the temperature of the anatase to rutile phase transition. 相似文献
844.
845.
乙酰丙酸和前体物对Rhodobacter sphaeroides 5-氨基乙酰丙酸合成的影响 总被引:3,自引:0,他引:3
球形红细菌Rhodobacter sphaeroides光合成培养过程中(接种量2g/L),分别以不同方式加入不同浓度的乙酰丙酸(LA)、前体物(甘氨酸、琥珀酸),发现LA(30mmol/L)分3次加入,甘氨酸(60mmol/L)分2次加入,可使5-氨基乙酰丙酸合成酶(ALAS)的活性(149.1U/mg)提高,而其脱水酶(ALAD)活性(143.4U/mg)降低,使ALA产量提高到33.8mmol/L.图2参9 相似文献
846.
土壤环境中活性X-3B红染料的淋溶行为与淹水释放模拟研究 总被引:6,自引:0,他引:6
采用土柱模拟实验对土壤环境中活性X-3B红染料的淋溶行为及向下迁移能力进行研究,结果表明,活性X-3B红染料这一有机污染物在土壤中的淋溶及向下迁移是一指数函数可以表达的动态过程,其可淋失能力因土壤类型不同而有较大的差异,其顺序为:褐土>棕壤>红壤>水稻土,究其原因,主要与土壤本身的各理化特性有关,即可淋失能力不仅与土壤粘粒和有机质含量存在显著负相关,与土壤pH值存在显著正相关,土壤阳离子交换量也对其可淋失能力具有一定的贡献,是土壤各理化特性的综合。此外,通过污染土壤淹水实验,初步确定土壤中活性X-3B红染料具有释放到地表水体中的较大环境风险。 相似文献
847.
N. Tommerup F. Søndergaard A. Hanauer I. Oberle J. Bang B. Barbi B. Bech K. Davies U. Froster-Iskenius K.-H. Gustavson C. B. van der Hagen A. Heiberg U. Kristoffersen M. Mikkelsen P. Miny K. B. Nielsen K. Rasmussen A. Schinzel L. Tranebjaerg T. Tønnesen J. Wahlström 《黑龙江环境通报》1991,11(8):609-619
Early prenatal diagnosis of the fragile X was attempted in 44 pregnancies, including one twin pregnancy at risk of Martin-Bell (MB) syndrome. The sex ratio was 24M:21F. The fragile site was reproducibly demonstrated in cultured chorionic villus (CV) cells in eight male and five female fetuses. Six of the male and three of the female fetuses were terminated. Simultaneous RFLP analysis provided confirmative data with flanking DNA markers in 3 of 13 analysed cases. Recombination and/or non-informativeness at available distal and/or proximal loci were found in nine cases. In one male fetus, discordance between the haplotype and cyto-genetics (fragile-X-negative) suggested the presence of a normal male transmitter, a double meiotic cross-over within the region, or a false-negative cytogenetic diagnosis. However, discordance between prenatal and post-termination/postnatal cytogenetic findings was not observed in this series. The use of excess thymidine for induction of the fragile X in cultured CV cells provided in the majority of cases a safe and rapid method for cytogenetic diagnosis, with options for early induced termination in fragile-X-positive pregnancies, for simultaneous RFLP analysis, and for subsequent second-trimester analysis of fetal blood in complicated cases. 相似文献
848.
Julie S. Fryburg Miriam S. Dimaio Teresa L. Yang-Feng Maurice J. Mahoney 《黑龙江环境通报》1993,13(6):481-494
Thirty-nine (2.3 per cent) of 1724 chromosome studies from diagnostic chorionic villus samplings (CVS) done between 1983 and 1990 showed either level III (true) mosaicism (1.2 per cent) or level II (pseudo-) mosaicism (1.1 per cent) for chromosomal aneuploidy. Follow-up information on these 39 pregnancies was collected from questionnaires to families, paediatricians, and obstetricians. For all cases in which the pregnancy was continued and further testing was accomplished, the mosaicism was felt to be confined to the placenta. As compared with a control group of pregnancies evaluated by CVS with normal karyotypes, there was no increased incidence of pregnancy loss, congenital malformations, or developmental delay in the infants. Although intrauterine growth retardation occurred in several of the level III mosaic cases, adequate catch-up growth has been demonstrated. 相似文献
849.
850.