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31.
为查明硫酸工业中主要重金属的危害以及不同制酸工艺产生的危害差异,对辽宁省主要生产硫酸企业进行了调研,并应用MEG法,对矿石原料中重金属的含量进行了数学模型分析。  相似文献   
32.
大辽河流域环境变化卫星遥感监测研究   总被引:1,自引:0,他引:1  
将中巴地球资源一号卫星(CBERS—1)采集到的数据与地面监测站、数据传输与处理系统、地理信息系(GIS)相结合,可以实现对区域环境准确、客观、动态、简捷、快速的监测。在全球定位系统(GPS)支持下,对大辽河流域精选地面解译标志,开展野外实地调查及CBERS-1卫星数据遥感分析,在系统设计与开发中坚持规范化、完备性、可操作性、先进性原则的基础上,建立了可运行的环境动态监测调控信息系统。  相似文献   
33.
"三S"技术应用与环境科技发展   总被引:3,自引:0,他引:3  
叙述了遥感,全球定位系统和地理信息系统和环境科技发展的关系,以及在环境科技中的实际应用,提出了在大力开展集RS,GPS,GIS于一体,适合环境科学应用的,综合多功能的“三S”技术,以适应可持续发展的需要。  相似文献   
34.
针对现有生态承载力评价研究中时间动态性、空间差异性考虑不足等问题,引入系统动力学(SD)模型,围绕生态承载力关键指标实施三峡库区分单元的系统仿真模拟和预测,整合生态承载力综合评价方法,对不同控制单元承载力状况进行动态评价. 结果表明:①2010年三峡库区生态承载力指数为0.55,为弱可承载状态. 生态承载力限制因素分析显示,长江嘉陵江重庆市辖区控制单元、长江涪陵区万州区控制单元主要受制于资源、环境要素,其他3个控制单元(澎溪河开县控制单元、长江云阳县巫山县控制单元、长江恩施州宜昌市控制单元)主要受制于社会、经济要素. ②现有发展趋势下,2010—2025年三峡库区生态承载力指数为0.48~0.57,呈先增后减的趋势,拐点出现在2015年附近,整体亦处于弱可承载状态. 2015年后,以资源、环境为主要限制因素的2个控制单元生态承载力指数开始逐年下降;以社会、经济为主要限制因素的其他3个控制单元生态承载力指数则呈延续上升态势. ③综合调控方案下,三峡库区生态承载力指数在2015年达到0.60,由弱可承载提升为基本可承载;至2018年,所有控制单元均达到基本可承载,生态承载力指数为0.60~0.76. 可见,综合调控方案对各控制单元人口、经济、环境、资源因素的调控行之有效.   相似文献   
35.
Technetium-99 (99Tc) is a radioactive isotope with a half-life of 2.13 × 105 year. 99Tc is a major radionuclide contaminant of concern for the world. Therefore, detailed understanding of 99Tc environmental chemistry is important for protecting human and ecological health. Here, we review the aqueous geochemistry of 99Tc, focusing on chemical properties and behavior of 99Tc in the hydrosphere and pedosphere. We describe the general chemistry of Tc including coordination chemistry, isotope chemistry and solid-state chemistry. Then we present anthropogenic and indigenous sources of 99Tc and their environmental distribution. We also discuss the radiotoxicity of 99Tc and the use of 99Tc for medical purpose. Tc biogeochemistry is described through sorption and desorption reactions at the mineral–water interface, thermodynamic of surface complexation, abiotic and biotic redox reaction of Tc(VII). Finally, we summarize the 99Tc remediation technologies including cement waste forms, natural remediation, vitrification, nuclear waste transmutation.  相似文献   
36.
The present research was intended to determine the suitability of the CALUX assay as a screening method for dioxins in fish oil used as a feed ingredient in Japan. Alteration of TEQ in fish oil according to newly proposed toxic equivalency factors (TEF) is also discussed. In the analysis, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in 41 fish oil samples were determined by using high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) and CALUX bioassay. The mean TEQ values derived from 1998 WHO-TEF of PCDD/Fs and DL-PCBs were 2.6 and 9.9 pg g(-1) (ww), respectively. The levels of TEQ derived from the recently re-evaluated 2005 WHO-TEF were slightly lower than those of the former in both groups. Notably, the contribution of mono-ortho DL-PCBs to total 2005 WHO-TEQ was considerably decreased compared to the case of 1998 WHO-TEQ, resulting from the reduction in its TEF values, while the non-ortho DL-PCBs contribution was increased. The mean TEQ determined by CALUX assay for PCDD/Fs was approximately three times higher, whereas DL-PCBs was approximately two times lower than WHO-TEQ determined by HRGC/HRMS; the sum of PCDD/Fs and DL-PCBs was very similar by both methods. The correlation coefficients of TEQ between the CALUX assay and HRGC/HRMS analysis were 0.84, 0.89, and 0.90 for PCDD/Fs, DL-PCBs, and the sum, respectively. These results suggest that the CALUX assay is a very useful method for the screening of dioxin-related compounds in fish oils.  相似文献   
37.
In the actual environment, temperatures fluctuate drastically through season or global warming and are thought to affects risk of pollutants for aquatic biota; however, there is no report about the effect of water temperature on toxicity of widely used herbicide diuron to fresh water microalgae. The present research investigated inhibitory effect of diuron on growth and photosynthetic activity of a green alga Pseudokirchneriella subcapitata at five different temperatures (10, 15, 20, 25, and 30 °C) for 144 h of exposure. As a result, effective diuron concentrations at which a 50 % decrease in algal growth occurred was increased with increasing water temperature ranging from 9.2 to 20.1 μg L–1 for 72 h and 9.4–28.5 μg L–1 for 144 h. The photochemical efficiency of photosystem II (F v/F m ratio) was significantly reduced at all temperatures by diuron exposure at 32 μg L–1 after 72 h. Inhibition rates was significantly increased with decreased water temperature (P?<?0.01). Intracellular H2O2 levels as an indicator of oxidative stress were also decreased with increasing temperature in both control and diuron treatment groups and were about 2.5 times higher in diuron treatment groups than that of controls (P?<?0.01). Our results suggest water temperatures may affect the toxicokinetics of diuron in freshwater and should therefore be considered in environmental risk assessment.  相似文献   
38.
为了验证两性修饰磁化炭材料对紫色土吸附菲的增强作用,采用共沉淀负载Fe_3O_4法和湿法有机负载分别制备了磁化炭(MC)和不同十二烷基二甲基甜菜碱(BS-12)修饰比例的两性修饰磁化炭(BS+MC),将其以1%的质量比加入到紫色土(PS)中,分别形成PS_(MC)和PS_(BS+MC)混合样品,批处理法研究各混合样品对菲的等温吸附和热力学特征,并对比了不同温度、离子强度和pH值对菲吸附的影响。结果表明:(1) MC和BS-MC材料的添加均增强了PS对菲的吸附能力,菲吸附量呈现PS_(200BS+MC)> PS_(150BS+MC)> PS_(100BS+MC)> PS_C> PS_(MC)> PS_(50BS+MC)> PS_(25BS+MC)> PS的趋势,PS_(BS+MC)对菲的吸附量随着添加材料上BS-12修饰比例的增加而增加。(2)菲在各供试土样上的吸附均表现为增温负效应(物理吸附),溶液pH值变化仅对PS_(150BS+MC)和PS_(200BS+MC)吸附菲有显著影响。离子强度增大不利于各供试土样对菲的吸附。(3) Henry模型适用于描述菲在供试土样上的等温吸附,且该过程呈现自发的、焓减和熵增的特征。从PS_C到PS_(MC)再到PS_(BS+MC),吸附过程呈现自发性、放热量和混乱度均增大的特征。  相似文献   
39.
After packing a compact of coal fly ash mixed with 3.5?M (mol/L) sodium hydroxide solution into a cylindrical plastic mold at 80?°C and 50?% relative humidity for 24?h, the plastic mold was released and the compact was immersed in 3.5?M sodium hydroxide solution at 80?°C for 48?h. When the resultant compact was removed from the solution and cured at 80?°C and 50?% relative humidity for 7?days, a bulk material with zeolite was formed. The strength of the resultant bulk material was a result of the formation of geopolymer (alkali-activated cement). The specific surface area and the compressive strength of the bulk body sample were 21.4?m2/g and 29.0?MPa, respectively. According to a quantitative analysis conducted using the X-ray diffraction (XRD) technique, the content of the formed Na-P type zeolite was estimated to be approximately 28.2?% in mass ratio. The pore size of the resultant bulk materials with zeolite ranges from sub-nanometer to several tens of nanometers, so the resultant bulk material with zeolite exhibited excellent water vapor retention characteristics.  相似文献   
40.
Blooms of the toxic dinoflagellate Heterocapsa circularisquama cause massive bivalve kills in Japan. Mariculture of the Japanese pearl oyster, Pinctada fucata martensii, is the industry most affected by these blooms, especially in Ago Bay, Mie Prefecture, where they are frequent, cause mass mortality of oysters, and overlap with their spawning season. The goal of this August 2009 study was to assess the effects of a toxic strain of H. circularisquama isolated from Ago Bay on gametes, fertilization, and embryo development of pearl oysters. Spermatozoa, eggs, spermatozoa and eggs, and fertilized eggs of pearl oysters from Ago Bay were exposed to H. circularisquama at cell densities reported during the bloom (10–104 cells mL?1) for different periods of time. The concentration of H. circularisquama, exposure duration, and their interactions all had significant effects on gamete quality, fertilization, and embryo development. The motility and swimming velocity of spermatozoa, egg viability, fertilization, and embryo development rate were significantly reduced in all concentrations, with a cell density of 10 cells mL?1 determined to be the critical density of H. circularisquama for deleterious effects. This is the first evidence of inimical effects of an HAB species on bivalve spermatozoa upon direct exposure. Further field and laboratory studies are required to investigate the potential effects of H. circularisquama blooms on the reproduction and recruitment of Japanese pearl oysters and other bivalves.  相似文献   
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