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   338篇
  免费   20篇
  国内免费   78篇
安全科学   1篇
废物处理   5篇
环保管理   22篇
综合类   141篇
基础理论   64篇
污染及防治   152篇
评价与监测   46篇
社会与环境   5篇
  2025年   6篇
  2024年   11篇
  2023年   12篇
  2022年   6篇
  2021年   14篇
  2020年   14篇
  2019年   10篇
  2018年   5篇
  2017年   9篇
  2016年   34篇
  2015年   13篇
  2014年   15篇
  2013年   21篇
  2012年   19篇
  2011年   53篇
  2010年   23篇
  2009年   29篇
  2008年   44篇
  2007年   20篇
  2006年   17篇
  2005年   5篇
  2004年   3篇
  2003年   4篇
  2001年   3篇
  2000年   8篇
  1999年   8篇
  1998年   10篇
  1997年   2篇
  1996年   6篇
  1995年   7篇
  1994年   3篇
  1992年   2篇
排序方式: 共有436条查询结果,搜索用时 15 毫秒
1.
         下载免费PDF全文
It is important to reduce Cd and As content in brown rice in contaminated paddy soils. We conducted research on the effects of rice husk ash (RHA) on the Cd and As in the rhizosphere microenvironment (soil, porewater, and iron plaque) and measured the Cd, As, and Si content in rice plants. The main elements in RHA were Si (29.64%) and O (69.17%), which had the maximum adsorption capacity for Cd was 42.49 mg/kg and for As was 18.62 mg/kg. Soil pH and available Si content increased, while soil available Cd and As decreased following application of 0.5%–2% RHA. RHA promote the transformation of Cd to insoluble fraction, while As was transformed from a poorly soluble form to a more active one. RHA reduced Cd content and increased Si content in porewater, and reduced As only at the later rice growth stages. RHA increased the amount of iron plaque, thereby decreasing the Cd content in iron plaque, while increased the As content in it. Cd and inorganic As content in brown rice were decreased, to 0.31 mg/kg and 0.18 mg/kg, respectively. The decrease of Cd in brown rice was due to the decrease of Cd mobility in soil, thereby reducing root accumulation, while the decrease of As in brown rice was affected by the transport from roots to stems. Therefore, RHA can be considered as a safe and efficient in-situ remediation amendment for Cd and As co-contaminated paddy soil.  相似文献   
2.
The arsenic and antimony balance in two municipal waste incinerators was investigated. Initially, the production rates of ash and wet scrubber effluent were estimated. Then the arsenic and antimony in the ash and wet scrubber effluent were determined, which gave an estimate of the elemental balance. The total amounts of arsenic and antimony in the municipal waste were 0.9 g/t and 30–44 g/t, respectively. The distributions to fly ash were 45–47% and 33–74% for arsenic and antimony, respectively. The distribution mechanisms of arsenic and antimony are discussed from the viewpoints of their thermodynamics as well as their initial valencies, which greatly affect their behaviour. Received: July 2, 1998 / Accepted: February 27, 1999  相似文献   
3.
    
Today, Bangladesh is confronted with an immense water supply crisis: the decline of surface water bodies as well as a fall in the water table, together with the multiple pollution of the water in general, has put pressure on a precious resource that needs to meet the demand of a growing population. However, the most serious problem became public just four years ago—the contamination of the groundwater with arsenic. Considering the extent of the water supply problem, solutions for the future provision of safe drinking water are urgently needed. This article argues that ponds, a traditional water source in Bangladesh, could contribute to a solution. However, it is essential to recognise the problems and advantages of ponds in order to make suggestions on how to integrate ponds into the national water policy. Therefore, this paper analyses pond management—the use, maintenance and control of ponds—and its change from the past to the present. A holistic, dynamic and actor-oriented approach on a small scale was proved to be the appropriate instrument for this analysis.  相似文献   
4.
环境砷污染与健康   总被引:1,自引:1,他引:1  
顾兴平  顾永祚 《四川环境》1999,18(3):11-14,22
本文论述了环境砷污染对健康的影响,包括砷中毒、机理、危害及分析方法。  相似文献   
5.
联用技术在砷形态分析中的研究进展   总被引:1,自引:0,他引:1  
摘要:目前用于元素砷的形态分析技术主要是色谱与原子光谱、质谱等的联用,最常用的是HPLC与ICP—OES、ICP—MS的联用,方法准确可靠,灵敏度高,但是不能提供砷化合物的分子结构信息。因此以色谱一电喷雾质谱(ESI—MS)的联用作为定性分析的主要手段,但是ESI—MS灵敏度低,易受基体干扰,因此需要复杂的前处理技术。  相似文献   
6.
Cadmium(Cd)and arsenic(As)co-contamination has threatened rice production and food safety.It is challenging to mitigate Cd and As contamination in rice simultaneously due to their opposite geochemical behaviors.Mg-loaded biochar with outstanding adsorption ca-pacity for As and Cd was used for the first time to remediate Cd/As contaminated paddy soils.In addition,the effect of zero-valent iron(ZVI)on grain As speciation accumulation in alkaline paddy soils was first investigated.The effect of rice straw biochar(SC),magnesium-loaded rice straw biochar(Mg/SC),and ZVI on concentrations of Cd and As speciation in soil porewater and their accumulation in rice tissues was investigated in a pot experiment.Addi-tion of SC,Mg/SC and ZVI to soil reduced Cd concentrations in rice grain by 46.1%,90.3%and 100%,and inorganic As(iAs)by 35.4%,33.1%and 29.1%,respectively,and reduced Cd con-centrations in porewater by 74.3%,96.5%and 96.2%,respectively.Reductions of 51.6%and 87.7%in porewater iAs concentrations were observed with Mg/SC and ZVI amendments,but not with SC.Dimethylarsinic acid(DMA)concentrations in porewater and grain increased by a factor of 4.9 and 3.3,respectively,with ZVI amendment.The three amendments affected grain concentrations of iAs,DMA and Cd mainly by modulating their translocation within plant and the levels of As(Ⅲ),silicon,dissolved organic carbon,iron or Cd in porewater.All three amendments(SC,Mg/SC and ZVI)have the potential to simultaneously mitigate Cd and iAs accumulation in rice grain,although the pathways are different.  相似文献   
7.
    
Arsenic(As) and antimony(Sb) are usually coexistent in mine wastes and pose a great threat to human health. The As immobilization by nano zero-valent iron(n ZVI) is promising, however, the stabilization for co-occurring As and Sb is not known. Herein, the immobilization and transformation of As and Sb in n ZVI-treated sediments were evaluated using complementary leaching experiments and characterization techniques. Raw sediment samples from a gold-antimony deposit revealed the co-existence of ul...  相似文献   
8.
    
The catalytic oxidation effect of MnSO4 on As(III) by air in an alkaline solution was investigated. According to the X-ray diffraction (XRD), scanning electron microscope-energy dispersive spectrometer (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) analysis results of the product, it was shown that the introduction of MnSO4 in the form of solution would generate Na0.55Mn2O4·1.5H2O with strong catalytic oxidation ability in the aerobic alkaline solution, whereas the catalytic effect of the other product MnOOH is not satisfactory. Under the optimal reaction conditions of temperature 90°C, As/Mn molar ratio 12.74:1, air flow rate 1.0 L/min, and stirring speed 300 r/min, As(III) can be completely oxidized after 2 hr reaction. The excellent catalytic oxidation ability of MnSO4 on As(III) was mainly attributed to the indirect oxidation of As(III) by the product Na0.55Mn2O4·1.5H2O. This study shows a convenient and efficient process for the oxidation of As(III) in alkali solutions, which has potential application value for the pre-oxidation of arsenic-containing solution or the detoxification of As(III).  相似文献   
9.
    
<正>Arsenic(As)is a well-recognized toxicant and carcinogen.Chronic exposure to inorganic arsenic causes a range of human cancers(e.g.,skin,bladder,and lung)and increases the risk of developing diabetes,hypertension,and cardiovascular and neurological diseases.The prevalence of arsenic species and the severity of their health effects continue to drive and demand for extensive research(Carlin et al.,2016).  相似文献   
10.
  总被引:1,自引:0,他引:1  
Arsenic (As) is a notoriously toxic pollutant of health concern worldwide with potential risk of cancer induction, but meanwhile it is used as medicines for the treatment of different conditions including hematological cancers. Arsenic can undergo extensive metabolism in biological systems, and both toxicological and therapeutic effects of arsenic compounds are closely related to their metabolism. Recent studies have identified methylated thioarsenicals as a new class of arsenic metabolites in biological systems after exposure of inorganic and organic arsenicals, including arsenite, dimethylarsinic acid (DMAV), dimethylarsinous glutathione (DMAIIIGS), and arsenosugars. The increasing detection of thiolated arsenicals, including monomethylmonothioarsonic acid (MMMTAV), dimethylmonothioarsinic acid (DMMTAV) and its glutathione conjugate (DMMTAVGS), and dimethyldithioarsinic acid (DMDTAV) suggests that thioarsenicals may be important metabolites and play important roles in arsenic toxicity and therapeutic effects. Here we summarized the reported occurrence of thioarsenicals in biological systems, the possible formation pathways of thioarsenicals, and their toxicity, and discussed the biological implications of thioarsenicals on arsenic metabolism, toxicity, and therapeutic effects.  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