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   463篇
  免费   6篇
  国内免费   20篇
安全科学   79篇
废物处理   16篇
环保管理   88篇
综合类   171篇
基础理论   31篇
污染及防治   68篇
评价与监测   21篇
社会与环境   9篇
灾害及防治   6篇
  2023年   9篇
  2022年   4篇
  2021年   5篇
  2020年   15篇
  2019年   4篇
  2017年   6篇
  2016年   13篇
  2015年   12篇
  2014年   13篇
  2013年   35篇
  2012年   14篇
  2011年   21篇
  2010年   20篇
  2009年   20篇
  2008年   22篇
  2007年   22篇
  2006年   36篇
  2005年   13篇
  2004年   22篇
  2003年   39篇
  2002年   17篇
  2001年   15篇
  2000年   22篇
  1999年   25篇
  1998年   9篇
  1997年   9篇
  1996年   8篇
  1995年   4篇
  1994年   17篇
  1993年   8篇
  1992年   3篇
  1991年   1篇
  1989年   1篇
  1985年   1篇
  1984年   2篇
  1981年   1篇
  1978年   1篇
排序方式: 共有489条查询结果,搜索用时 0 毫秒
421.
本文通过室内实验,研究了细菌在黄土上的吸附解吸特征,并探讨了其在黄土上的吸附量对土壤石油降解的影响。结果表明,细菌在黄土上的吸附符合Langmuir等温吸附方程,当菌液浓度较低时,吸附量随浓度增加而急剧上升,随着菌液浓度进一步增加,吸附量随浓度的增加渐渐平缓;细菌在黄土上的解吸作用极弱,一旦被吸附后,较难被解吸,解吸量平均仅是吸附量的1%;随着细菌在土壤上吸附量的增加,降解率相应提高。当土中含油量为3.52%,菌液浓度为1.0×10^8个/ml,经过30d后,降解率可达到45%。  相似文献   
422.
Agricultural expansion and deforestation are spatial processes of land transformation that impact on landscape pattern. In peninsular Malaysia, the conversion of forested areas into two major cash crops—rubber and oil palm plantations—has been identified as driving significant environmental change. To date, there has been insufficient literature studying the link between changes in landscape patterns and land-related development policies. Therefore, this paper examines: (i) the links between development policies and changes in land use/land cover and landscape pattern and (ii) the significance and implications of these links for future development policies. The objective is to generate insights on the changing process of land use/land cover and landscape pattern as a functional response to development policies and their consequences for environmental conditions. Over the last century, the development of cash crops has changed the country from one dominated by natural landscapes to one dominated by agricultural landscapes. But the last decade of the century saw urbanization beginning to impact significantly. This process aligned with the establishment of various development policies, from land development for agriculture between the mid 1950s and the 1970s to an emphasis on manufacturing from the 1980s onward. Based on a case study in Selangor, peninsular Malaysia, a model of landscape pattern change is presented. It contains three stages according to the relative importance of rubber (first stage: 1900–1950s), oil palm (second stage: 1960s–1970s), and urban (third stage: 1980s–1990s) development that influenced landscape fragmentation and heterogeneity. The environmental consequences of this change have been depicted through loss of biodiversity, geohazard incidences, and the spread of vector-borne diseases. The spatial ecological information can be useful to development policy formulation, allowing diagnosis of the country’s “health” and sustainability. The final section outlines the usefulness of landscape analysis in the policy-making process to prevent further fragmentation of the landscape and forest loss in Malaysia in the face of rapid economic development.
Adnan A. HezriEmail:
  相似文献   
423.
建立了用活性炭作吸附剂、脱芳烃石油醚萃取、紫外分光光度法测定油烟挥发组分的方法。取家用抽油烟杯内的油烟气冷凝液加热到200C的样品萃取液作标准油品,在225nm处测紫外吸光值,绘制校准曲线,相关系数在0.986~0.999之间。实验样品分析结果表明,脱芳烃石油醚对样品中油烟挥发组分萃取率可达90%以上,样品测定重现率达76.7%。红外光谱分析标准油品挥发组分初步认定为烃类、卤代烃类、醇酚醚类、醛酮类、羧酸及其衍生物类、稠环杂环类和胺类等。  相似文献   
424.
基于油罐火灾数值模拟的模型选取与分析   总被引:2,自引:3,他引:2  
计算机模拟方法是当今研究油罐火灾发生、发展规律的重要手段。为此 ,从油罐燃烧的特点出发 ,搜集了当前最新的 1 7种火灾模型 ,对比分析了它们的特点和适用范围 ,并筛选出 7种适于模拟油罐火灾的模型 :ALOFT -FT ,FDS ,CFX ,FLUENT ,PHOENICS ,JASMINE和FIRE。通过对这些模型计算方法的进一步比较 ,分析了利用这 7种模型模拟油罐火灾的优点和缺点。最后 ,提出了运用FDS模型模拟油罐火灾的优势 ,并用其进行了计算和分析 ,得到了满意的结果  相似文献   
425.
河流泥沙吸附石油的实验研究   总被引:1,自引:0,他引:1  
研究河流中的泥沙对石油的吸附和解吸规律对建立水质数学模型及水质预测预报具有重要意义,可为水域石油污染的治理提供依据。本文根据静态实验研究成果,建立了通用的吸附反应方程,在水槽中进行了均匀输沙吸附实验,并用解析解进行计算与动态实验结果进行比较,其结果较为理想。最后对河流底沙的吸附进行了初步探讨,分析了石油向底沙层扩散的过程。  相似文献   
426.
Adsorptive bleaching potentials of activated animal bone on palm oil was investigated. Palm oil was obtained locally from the mesocarp of oil palm fruits. The obtained palm oil was degummed, neutralized, and subjected to proximate analysis before bleaching. The animal bone–based activated carbon used as a bleaching material was locally prepared by cleaning, drying, carbonization, and chemical activation process. The prepared activated carbon (CBAC) was characterized using Fourier transform infrared, scanning electron microscopy, Braummer–Emmett–Teller, and x‐ray diffraction (XRD) methods. Bleaching of the prepared palm oil on CBAC was done at different process conditions. The characterization results of BET analysis show that CBAC has a surface area of 593.270 m2/g, micropore surface area 595.56 m2/g, micropore volume 0.212 cm3/g, Langmuir surface area 1.38e+04 m2/g, and adsorption energy 3.998 KJ/mol. XRD analysis indicates gypsum as the dominant mineral in the activated carbon sample. The CBAC efficiency of 75.14% was obtained for time/temperature interactions at 50 min/120°C while at 25 g/50 min dosage/time interactions an efficiency of 75.17% was obtained.  相似文献   
427.
石油裂解气中汞的形态主要有气态汞和颗粒态汞。《空气和废气监测分析方法》(第四版),废气中汞有高锰酸钾溶液吸收法和玻璃纤维滤膜(滤筒)两种采样方法。溶液吸收法适合气态汞采样,滤膜(滤筒)采样法适合颗粒态汞采样。本文将两种采样方法串联对某石化企业的石油裂解气总汞进行监测分析,结果表明:石油裂解气中颗粒态汞与气态汞比例约为1:9;气态汞样品平行性较好,两个点位6次RSD值分别为17.2%和17.0%;颗粒态汞两个点位6次RSD值分别为25.3%和23.1%。建议对石油裂解气总汞监测采用玻璃纤维滤膜和高锰酸钾溶液吸收法串联采样。  相似文献   
428.
针对渤西油田QK18-1钻井平台含油废水处理系统存在的主要问题,即原油缓冲罐因进水质、水量变化较大造成罐体液位波动、后段水力旋流器供压不稳定、除油效果差、出水超标等,通过系统优化提出了稳流、稳压的改进措施,实践表明:在水力旋流器前配置稳压罐、增设回流管阀和在线液位控制,极大地提高了除油效果,使出水石油类稳定达到国家排放标准,同时提高了系统的处理能力。  相似文献   
429.
The high demand for water in oil sands operations in addition to the shortage of fresh water resources mandate continuous search for reliable and cost effective water treatment technologies. Micellar-enhanced ultrafiltration (MEUF) is potentially applicable to produced water treatment. MEUF is, however, susceptible to membrane plugging and back contamination, especially at high surfactant dosages. Recent investigations showed that addition of small amounts of a non-ionic surfactant to an ionic surfactant solution reduces the critical micellar concentration (CMC) of the mixed surfactant solution, and consequently reduces the surfactant dosage required to achieve certain removal of contaminants using MEUF. In the present study a naphthenic acid, octanoic acid, typically existing in produced water is shown to play a similar role as the non-ionic surfactant when added to the cationic surfactant cetylpyridinium chloride (CPC). Cross-flow MEUF using three different molecular weight cutoffs (MWCOs) of polyacrylonitrile (PAN) hollow fiber membranes was used to treat synthetic produced water containing p-xylene. The mixed CPC/octanoic acid solution removed comparable percentages of p-xylene contaminant at much lower concentrations of CPC. Decreasing CPC concentration in the feed resulted in less fouling and higher permeate flux and reduced back contamination. This, in turn, enhanced the performance of MEUF.  相似文献   
430.
高吸油树脂的新进展及应用   总被引:5,自引:0,他引:5  
综述了高吸油树脂的发展历史及最新进展,介绍了其吸油机理。讨论了高吸油树脂在含油废水治理及其他领域的应用。指出高吸油树脂是一类性能优异的新型环保材料。提出了高吸油树脂应在原料的选择、性能的改进、结构分析、再生利用、开拓新的应用领域、新聚合工艺等方面进行更深入的研究。  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