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   737篇
  免费   57篇
  国内免费   243篇
安全科学   44篇
废物处理   11篇
环保管理   51篇
综合类   453篇
基础理论   191篇
污染及防治   134篇
评价与监测   116篇
社会与环境   34篇
灾害及防治   3篇
  2024年   1篇
  2023年   24篇
  2022年   31篇
  2021年   32篇
  2020年   34篇
  2019年   33篇
  2018年   28篇
  2017年   31篇
  2016年   46篇
  2015年   30篇
  2014年   34篇
  2013年   78篇
  2012年   45篇
  2011年   63篇
  2010年   44篇
  2009年   37篇
  2008年   54篇
  2007年   42篇
  2006年   36篇
  2005年   32篇
  2004年   32篇
  2003年   24篇
  2002年   30篇
  2001年   22篇
  2000年   25篇
  1999年   21篇
  1998年   26篇
  1997年   10篇
  1996年   16篇
  1995年   16篇
  1994年   12篇
  1993年   14篇
  1992年   11篇
  1991年   2篇
  1990年   10篇
  1989年   4篇
  1986年   1篇
  1984年   1篇
  1982年   2篇
  1976年   2篇
  1972年   1篇
排序方式: 共有1037条查询结果,搜索用时 968 毫秒
501.
Laser-induced breakdown spectroscopy (LIBS) was applied for the detection of toxic metals in oil spill contaminated soil (OSCS). The OSCS samples were collected from Khursania Saudi Arabia along the coast of Persian Gulf exposed to oil spills in 1991 Gulf war. Environmentally important elements like Aluminum Magnesium, Calcium, Chromium, Titanium, Strontium, Iron, Barium, Sodium, potassium, Zirconium and Vanadium from the contaminated soil have been detected. Optimal experimental conditions for analysis were investigated. The LIBS system was calibrated using standard samples containing these trace elements. The results obtained using Laser-Induced Breakdown Spectroscopy (LIBS) were compared with the results obtained using Inductively Coupled Plasma Emission Spectroscopy (ICP). The concentrations of some elements (Ba and Cr) were found higher than permissible safe limits. Health risks associated with exposure to such toxic elements are also discussed.  相似文献   
502.
Washoff of road deposited sediment into storm drainsystems is one of the major contributors to nonpoint sourcepollution in urban fluvial networks. These sediments contain avariety of potentially toxic organic and inorganic contaminants.Road sediment from 13 locations in an urban (non-industrialized)drainage basin, and soil from 10 background (control) locationswere collected to assess total and labile fractions of Al, Co,Cu, Fe, Mn, Ni, Pb and Zn. Four digestions, of varying strength,were used to assess contaminant levels, these included: a totalfour-acid digestion, a microwave-assisted digestion withconcentrated nitric acid (USEPA Method 3051), a 0.5 M `cold' HCl,and a 0.05 M EDTA (pH 7). Road sediment data indicate that Al,Co, Fe, Mn and Ni were primarily lithogenic in origin, while Cu,Pb and Zn showed very significant anthropogenic signals, mostprobably from vehicle-related sources. Median Pb concentrationenrichment ratios for the EDTA extraction were about 42,indicating an extreme anthropogenic signal. The weak extractants(HCl and EDTA) are considered in this study to be superior intheir ability to characterize the degree of anthropogeniccontamination and should be utilized more widely in environmentalcontaminant studies.  相似文献   
503.
Due to the consumption of the herby cheese in south eastern Anatolia-Turkey is at high ratio, chemical parameters such as dry matter, pH, acidity, aCl, protein, fat and trace metal contents in 50 different herby cheeses produced at this region have been determined in the presented study. The content of lead, copper, cobalt, nickel, chromium, cadmium, and iron have been analyzed by flame atomic absorption spectrometer in air/acetylene flame after combination ash digestion method and wet digestion method. The mean concentration of lead, copper, cobalt, nickel, chromium and cadmium in our samples are higher than literature values except iron.  相似文献   
504.
石家庄市大气颗粒物元素组分特征分析   总被引:2,自引:1,他引:1  
为研究石家庄市大气颗粒物的污染特征及其来源,于2013年4—5月在主城6区分别采集TSP、PM10和PM2.5颗粒物样品,利用ICP-MS分析其中的22种元素浓度。结果表明,石家庄市城区Ca、Fe元素在各粒径颗粒物中含量都较高,PM2.5中的S、K含量较高,PM10和TSP中Mg、Al的浓度相对较高。颗粒物的主要来源为燃煤尘、道路尘和建筑尘,TSP、PM10和PM2.5具有较好的统计相关性和同源性。  相似文献   
505.
采用4种微波消解体系对聚四氟乙烯(PTFE)材质滤膜采集的PM2.5样品进行消解,利用电感耦合等离子体质谱(ICP-MS)测定样品中Cr、Mn、Cu、As、Cd 5种重金属元素含量,并计算其空白加标和样品加标回收率,建立了测定PTFE材质滤膜采集的PM2.5样品中重金属元素的最优微波消解体系。结果表明,4种消解体系下,空白加标回收率和样品加标回收率均处于合理范围,分别为95.3%~116.3%和93.3%~118.5%。其中,HNO3放置过夜+H2O2消解体系具有空白值低、测定稳定性强、操作简便、绿色环保、对人体健康危害小等优点,能够满足大批量PM2.5样品中重金属总量的快速、高效、准确分析的要求。  相似文献   
506.
In order to evaluate the impact of atmospheric pollutants emitted by the industrial settlement of Milazzo (Italy) on agriculture, sulphur dioxide and ozone levels in air were monitored and the data were used to estimate yield losses of the most widespread cultures. Trace element concentrations in crops and soils were also detected and metabolic profiles of soil microbial communities were considered. Vibrio fischeri test was used to appraise airborne pollutant ecotoxicity and epidemiological studies on causes of death distribution were carried out to characterize health state of people living in the area. All the sampling points were selected in farms on the basis of a theoretical meteo-diffusive model of industrial air pollutants. Experimental SO2 and O3 values mainly exceeded the threshold established by Italian and EU regulations to protect vegetation and they correspond to estimated significant crop losses. Conversely toxic element residues in soils and in agroalimentary products were generally lower than the fixed values. SO2 and O3 concentrations, toxic element contents and ecotoxicity levels of airborne pollutants were not related only to industrial site emissions, while the fluctuations on metabolic profiles of soil microbial communities seem to agree with the predicted deposition of xenobiotic compounds from the industrial plants. The epidemiological study evidenced a better health state of populations living in the investigated area than in the Messina province and the Sicily region but, inside the area, males living in the municipalities closest to the industrial settlement exhibited a worst health state than those in the very far ones.  相似文献   
507.
采用高分辨电感耦合等离子体质谱法测定地下水中14种稀土元素,并选择Rh作内标,可消除测定中的质谱干扰和非质谱干扰,使方法在0μg/L~100μg/L范围内线性良好。方法检出限为0.002μg/L~0.005μg/L,实际水样的加标回收率为80.0%~117%,RSD为2.1%~3.8%。  相似文献   
508.
A field study was conducted around two thermal power plants of India to quantify the changes in foliar elemental concentrations due to emission in a low rainfall tropical area. Sulphur dioxide and particulates were at high levels which may cause serious ecological effects. Emission from the power plants has altered the elemental concentrations in the leaves of evergreen and deciduous plants. The foliar total-S and SO4 2–-S levels were significantly higher in all the plants growing at polluted sites. However, the organic-S content was more or less unaltered. In evergreen plants, the SO4 2–-S content increased gradually from summer through winter, whereas in the deciduous plants there was a higher magnitude of increase after onset of new leaves during summer. With the increasing pollution load, foliar Ca2+ and K+ contents increased, whereas N content decreased. The reduction in N content was greater during summer in evergreen plants and during winter in deciduous plants. The plants growing closer to the power plants accumulated more trace elements (Mn, Fe, Cd, Pb and Ni) as compared to those growing at distant sites. In deciduous plants the leaf fall during winter lowered down the trace element  相似文献   
509.
采用微波消解-电感耦合等离子体质谱法测定水系沉积物中12种元素,通过优化试验相关条件消除质谱干扰和非质谱干扰对测定的影响,使方法在0μg/L~200μg/L范围内线性良好,当取样质量为0.25 g,定容体积为50 m L时,各元素的方法检出限为0.002 mg/kg~0.05 mg/kg。用该方法测定沉积物标准物质,6次测定结果均在标准值范围内,RSD为1.3%~6.1%,实际样品的加标回收率为83.0%~97.0%。  相似文献   
510.
用小流量TSP采样器对佛山市4家陶瓷企业内无组织排放特征明显的车间TSP进行了测定,并采用ICP-MS技术对TSP的金属元素成分进行了分析,测试结果中,共有43种金属元素被检出,各车间内主要金属元素浓度值较高。TSP中金属元素富集因子的研究结果表明,共有11类元素富集值大于10而出现了富集的特征,另有14个元素富集值低于1。以元素富集因子进行的聚类分析,除8种富集元素外,35种金属元素聚集成一个大类群。  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