全文获取类型
收费全文 | 314篇 |
免费 | 11篇 |
国内免费 | 138篇 |
专业分类
安全科学 | 35篇 |
废物处理 | 21篇 |
环保管理 | 17篇 |
综合类 | 143篇 |
基础理论 | 55篇 |
污染及防治 | 154篇 |
评价与监测 | 9篇 |
社会与环境 | 7篇 |
灾害及防治 | 22篇 |
出版年
2023年 | 4篇 |
2022年 | 11篇 |
2021年 | 12篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 13篇 |
2017年 | 12篇 |
2016年 | 15篇 |
2015年 | 22篇 |
2014年 | 20篇 |
2013年 | 35篇 |
2012年 | 37篇 |
2011年 | 27篇 |
2010年 | 22篇 |
2009年 | 14篇 |
2008年 | 21篇 |
2007年 | 18篇 |
2006年 | 20篇 |
2005年 | 22篇 |
2004年 | 9篇 |
2003年 | 23篇 |
2002年 | 13篇 |
2001年 | 21篇 |
2000年 | 12篇 |
1999年 | 9篇 |
1998年 | 8篇 |
1997年 | 2篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1986年 | 2篇 |
1933年 | 1篇 |
排序方式: 共有463条查询结果,搜索用时 359 毫秒
431.
432.
β-胡萝卜素-15,15'-加氧酶(β-carotene-15,15'-momoxygenase 1,bco1)是β-胡萝卜素转化成维生素A过程中的关键酶,bco1与bco1l是编码此酶的主要基因。本实验利用CRISPR/Cas9技术敲除斑马鱼的与β-胡萝卜素-15,15'-加氧酶编码相关的基因bco1与bco1l,以便深入开展对斑马鱼bco1的功能研究。分别在斑马鱼bco1与bco1l基因2号外显子选取sg RNA识别位点,体外转录制备sg RNA并与Cas9 m RNA混合对斑马鱼Ⅰ细胞期受精卵进行显微注射,24 h后收集部分胚胎进行PCR检测并将PCR产物进行单克隆测序确定sg RNA的有效性,构建首建鱼,并在此基础上通过PCR检测、凝胶电泳及测序筛选可遗传突变体。本研究分别获得了bco1基因突变与bco1l基因突变,分析表明这些缺失和插入均可导致编码序列的移码,为研究鱼类胡萝卜素代谢及相关发育过程等后续研究提供了材料。 相似文献
433.
434.
The current status of the treatment and disposal of hazardous wastes in China is summarized on the basis of the results of
the Declaring and Registration Project initiated nationally in 1995. A principle framework for the sound management of hazardous
wastes is proposed, which includes three levels of technical solutions. Large-scale enterprises are encouraged to recycle,
to treat, and to dispose of wastes by means of constructing facilities, and to have their extra capacities available to the
public for a reasonable fee. Municipal governments, provincial governments, and the Central Government are to plan and construct
centralized facilities to recycle, treat, and dispose of wastes. For a solution at the manufacturing level, recycling is identified
as the main approach. Centralized facilities at the municipal level will mainly focus on special wastes that are unsuitable
to transport and store, such as hospital waste, and for the technical solution at this level, incineration and recycling are
identified as the main approaches. For the technical solution at the provincial and national levels, landfill and incineration
are identified as the main approaches. Based on this principle and the current available data on hazardous wastes, a preliminary
plan for the spatial distribution of cross-provincial centralized treatment and disposal facilities of hazardous wastes is
presented. The construction of approximately nine cross-provincial comprehensive facilities is proposed. A priority list for
the construction of these planned facilities is also presented. 相似文献
435.
对地矿部门近40年的工业卫生工作,包括尘、毒、噪声等有害因素的综合治理,职业病防治,作了简明回顾。对目前的情况进行了分析。对今后工作提出了初步建议及对策。 相似文献
436.
Lu WJ Wang HT Nie YF Wang ZC Huang DY Qiu XY Chen JC 《Journal of environmental science and health. Part. B》2004,39(5-6):871-887
A lab-scale composting experiment was carried out using vegetable and flower stalks waste to study the effectiveness of ligno-cellulolytic microorganisms (LCMs) obtained from the previous isolation on composting process, especially on enhancement of biodegradation rate of these organic materials. The addition of LCMs to compost showed promised to be a valuable asset by rendering timely benefits in efficiency, maturity, and quality of the composting. This was evidenced by a significant increase of temperature, O2 consumption and CO2 emission, and population density of LCMs in compost mass compared with that of biotic (addition of culture of horse feces) and abiotic (1% molasses amendment) treatments, as well as control trial. The phytotoxicity assay showed that the substrate became mature after 60 days' composting. The LCMs inoculation enhanced the biodegradation of the composting materials as evidenced by an increasing screening ratio (1.2 cm sieve pore) of 34.5% in the treated trail, compared with that of control, which elucidated that big advantage of adding selected inoculants over other treatment, and screening ratio is a reasonable index to compare the quality of different compost. However, the inoculation seemed to have no significant effect on the moisture content, pH, and the final organic carbon of the composting materials. 相似文献
437.
自然中心主义环境伦理思想作为目前最为热门的学科之一,自然同其它学科一样,有它产生的思想根源、现实缘由和直接的动因。工业社会的精神失落和蓬勃兴起的绿色运动是其思想诱因与直接动因,而它形成的现实缘由则主要是全球面临的生态困境以及对人与自然关系的重新认识。 相似文献
438.
介绍了湿法脱硫系统中真空皮带脱水机滤布的一种光漫反射纠偏装置,包括其主要部件如光漫反射传感器、电动推杆驱动装置、滤布控制滚轮等,重点阐述了光漫反射纠偏装置的工作原理及纠偏过程。光漫反射纠偏装置的主要原理是通过光漫反射传感器的输出信号来判断滤布的跑偏,根据光漫反射传感器的输出信号,DCS控制系统发送指令启动可伸缩的电动推杆装置来伸长和收缩推杆,从而控制滤布滚轮围绕着旋转点进行相应的倾斜调整,使滤布回到其中心位置。 相似文献
439.
440.
Qu Aibin Cao Tengrui Li Zixuan Wang Wenjuan Liu Ran Wang Xue Nie Yaxiong Sun Suju Liu Xuehui Zhang Xiaolin 《Environmental science and pollution research international》2021,28(47):67066-67081
Environmental Science and Pollution Research - Some studies have shown that maternal exposure to perfluoroalkyl substances (PFASs) may be associated with early attention deficit hyperactivity... 相似文献