首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   313篇
  免费   12篇
  国内免费   111篇
安全科学   16篇
废物处理   27篇
环保管理   13篇
综合类   176篇
基础理论   46篇
环境理论   1篇
污染及防治   122篇
评价与监测   8篇
社会与环境   9篇
灾害及防治   18篇
  2023年   4篇
  2022年   13篇
  2021年   8篇
  2020年   8篇
  2019年   7篇
  2018年   8篇
  2017年   15篇
  2016年   13篇
  2015年   19篇
  2014年   27篇
  2013年   32篇
  2012年   26篇
  2011年   27篇
  2010年   24篇
  2009年   24篇
  2008年   15篇
  2007年   23篇
  2006年   27篇
  2005年   9篇
  2004年   8篇
  2003年   21篇
  2002年   8篇
  2001年   12篇
  2000年   12篇
  1999年   6篇
  1998年   2篇
  1997年   12篇
  1996年   2篇
  1995年   9篇
  1994年   3篇
  1993年   2篇
  1991年   4篇
  1990年   2篇
  1988年   3篇
  1987年   1篇
排序方式: 共有436条查询结果,搜索用时 78 毫秒
111.
不同类型清水剂处理油田含聚污水的效果对比   总被引:1,自引:0,他引:1  
翟磊  王秀军  靖波  檀国荣 《化工环保》2016,36(2):124-130
考察了阳离子型CWC-14、非离子型NQS-01和阴离子型AQS-08 3类清水剂对油田含聚污水的处理效果,对比了它们的作用特点和絮体性能。实验结果表明:在清水剂加入量350 mg/L、处理温度65℃、搅拌转速300 r/min、搅拌时间5 min的条件下,CWC-14、NQS-01和AQS-08对含聚污水的除油率分别为98.8%、98.0%和99.4%;NQS-01受处理温度、搅拌条件影响较大;CWC-14受污水中聚合物质量浓度影响最大。清水剂的絮体特点与其作用机理有关,CWC-14的絮凝速率最快,起效时间最短,絮体呈黏性大块状;NQS-01的絮凝速率最慢,起效时间最长,絮体呈浮油状;AQS-08的絮凝速率和起效时间适中,絮体呈松散状、流动性好。对比结果表明,非阳离子型清水剂可有效避免油田含聚污水处理过程中的黏性油泥问题。  相似文献   
112.
This paper presents a study regarding the preparation of MgCr2O4 from waste tannery solution, and chromium leaching behavior is also investigated with varying amounts of sulfate, chloride and calcium. The phase transformation, crystallinity index and crystallite diameter were characterized using XRD, FT-IR and thermal analysis. A well-crystallized MgCr2O4 was successfully prepared at 1400 °C. The sintering temperature had a major impact on the formation of MgCr2O4 compared with sintering time. The MgCr2O4 phase was observed initially at 400 °C and its crystallite diameter increased with increasing temperature. The concentration of total chromium leached and Cr(VI) decreased gradually with increasing temperature. The considerable amount of Cr(VI) was found in the leachate at 300–500 °C caused by Cr(VI) intermediary products. Sulfate and chlorine could impact the transformation efficiency of chromium adversely, and chlorine has a more significant effect than sulfate. The presence of calcium disturbed the formation of MgCr2O4 and new chromium species (CaCrO4) appeared, which resulted in a sharp increase in the concentration of leached Cr(VI). Incorporating Cr(III) into the MgCr2O4 spinel for reusable products reduced its mobility significantly. This was demonstrated to be a promising strategy for the disposal of chromium containing waste resource.  相似文献   
113.
This study integrates the emotion and social influence literatures to examine how emotion recognition ability (ERA) relates to annual income. In a sample of 142 employee–peer–supervisor triads from a broad range of jobs and organizations, we find that people's level of ERA indirectly relates to how much they earn per year. The relationship between ERA and annual income is mediated sequentially through political skill and interpersonal facilitation. The results imply that emotional abilities allow people not only to process affect‐laden information effectively but also to use this information to successfully navigate the social world of organizations in the pursuit of prosperity. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
114.
To utilize visible light more effectively in photocatalytic reactions, a fly ash cenosphere (FAC)-supported CeO2-BiV04 (CeO2-BiVO4/FAC) composite photocatalyst was prepared by modified metalorganic decomposition and impregnation methods. The physical and photophysical properties of the composite have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and UV-Visible diffuse reflectance spectra. The XRD patterns exhibited characteristic diffraction peaks of both BiVO4 and Ce02 crystalline phases. The XPS results showed that Ce was present as both Ce4+ and Ce3+ oxidation states in Ce02 and dispersed on the surface of BiV04 to constitute a p-n heterojunction composite. The absorption threshold of the CeO2-BiVO4/FAC composite shifted to a longer wavelength in the UV-Vis absorption spectrum compared to the pure Ce02 and pure BiV04. The composites exhibited enhanced photocatalytic activity for Methylene Blue (MB) degradation under visible light irradiation. It was found that the 7.5 wt.% CeO2-BiVO4/FAC composite showed the highest photocatalytic activity for MB dye wastewater treatment.  相似文献   
115.
A laboratory study was conducted to examine cosolvent-enhanced in-situ chemical oxidation (ISCO) of perchloroethylene (PCE) using potassium permanganate (KMnO4). The conceptual basis for this new technique is to enhance permanganate oxidation of dense non-aqueous phase liquids (DNAPLs) with the addition of a cosolvent, thereby increasing DNAPL solubility while avoiding mobilization. Among 17 cosolvent candidates screened, tertiary butyl alcohol (TBA) and acetone were the most stable in the presence of KMnO4, both of which increased PCE aqueous solubility significantly, and therefore are suitable to be used as cosolvent in this study. Batch experiments indicated that the second-order rate constant for PCE oxidation by potassium permanganate was 0.043+/-0.002 M(-1) s(-1) in the purely aqueous (no cosolvent) solution. In the presence of 20% cosolvent (volume fraction=fc=0.2), the rate constant decreased to 0.036+/-0.003 M(-1) s(-1) with TBA and to 0.031+/-0.002 M(-1) s(-1) with acetone. However, in the presence of free-phase PCE, chloride ion concentration from PCE oxidation in acetone/water solutions (fc=0.2) was about twice that in aqueous solutions, indicating that the increase in PCE solubility more than compensated for the decrease in reaction rate constant, such that the oxidation efficiency of PCE was increased with cosolvent. A complete chlorine mass balance was observed in the aqueous system, whereas approximately 70% was obtained in TBA/water or acetone/water (fc=0.2). In soil columns containing residual DNAPL and subjected to isocratic flushing with step-wise increases in f(c) cosolvent, TBA at fc=0.2 resulted in PCE mobilization, whereas acetone at fc相似文献   
116.
三峡库区扩种龙眼荔枝的适宜性分析   总被引:1,自引:0,他引:1  
荔枝与龙眼系亚热带水果,集中分布于闽粤两省,三峡库区上段河谷两侧也有零星分布,是该类水果分布的最北界。这类水果在训区栽培始于汉唐时代,并被列为贡品荔枝与龙眼系喜温性水果,库区栽培间冻害发生,成为限制扩大栽培的主要因素,故多分布于万县-重庆江段两海拔200m上下地段,水库蓄水后,原栽培区部分被淹没,但水体有增温作用,为扩大栽培提供了有利的条件。研究了万县-重庆沿江两岸河谷地段与非河谷地段适宜载种范围  相似文献   
117.
利用化学清洗技术,对风机循环系统、油冷却系统进行杀灭微生物、除垢、去锈、管壁钝化、预膜处理,既保证了高炉的正常生产,又延长了风机的使用寿命。  相似文献   
118.
ABSTRACT: In conventional flood damage reduction studies, flood damage is usually estimated with a damage function according to the depth of inundation. However, this method may not reflect the conditions of each family residing in the floodplain because it ignores not only the distribution of flood damage but also the effect of building characteristics and residents' preparedness. This paper uses data from a questionnaire based survey (N= 3,036) conducted 17 months after the Tokai Flood of 2000 that caused disastrous losses to household properties. It provides a conceptual “doughnut structure” model of flood damage to houses and house contents and a mathematical basis for models to explore the determinants of flood damage. Besides the inundation depth, house type significantly affects both the house structural and content damage probabilities, while house ownership and house structure affect house damage probability but not house content damage probability at a given depth. Inundation depth, residing period, and household income significantly affect both house and content damage values. In addition, house ownership has a significant impact on the house damage value, while house structure has an impact on content damage value.  相似文献   
119.
预应力混凝土结构设计可靠度刍议   总被引:1,自引:1,他引:1  
预应力混凝土结构是我国土木、水利和交通工程中应用最广泛和最具潜力的一种结构。笔者就新公布的《混凝土结构设计规范》GB5 0 0 10— 2 0 0 2与原规范GBJ10— 1989关于预应力混凝土结构设计可靠度内容所作的重大调整以及部分更新进行了探讨。对新规范GB5 0 0 10— 2 0 0 2的学习、理解和贯彻执行有一定指导作用。  相似文献   
120.
炉底渣磨细优化其品质的试验   总被引:1,自引:0,他引:1  
余锦龙  翟建平  李琴  盛广宏 《环境工程》2006,24(5):50-52,55
以浙江长兴电厂所排的炉底渣为例,通过磨细将其加工成相当于国标Ⅱ级粉煤灰的产品。试验结果表明:长兴电厂炉底渣的化学成分以SiO2与Al2O3较高为特征,物相以玻璃体占绝对优势,微量元素和放射性元素含量均在国标规定的安全范围内;磨细炉底渣的45μm筛余量控制在10%左右时其品质为最优;磨细炉底渣的火山灰活性要优于磨细Ⅱ级粉煤灰的。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号