全文获取类型
收费全文 | 46篇 |
免费 | 3篇 |
国内免费 | 26篇 |
专业分类
安全科学 | 3篇 |
废物处理 | 3篇 |
环保管理 | 2篇 |
综合类 | 33篇 |
基础理论 | 12篇 |
污染及防治 | 18篇 |
评价与监测 | 2篇 |
社会与环境 | 1篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 5篇 |
2022年 | 3篇 |
2019年 | 3篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 8篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 2篇 |
2011年 | 7篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 5篇 |
2007年 | 1篇 |
2006年 | 3篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
排序方式: 共有75条查询结果,搜索用时 31 毫秒
41.
Stelyus L. Mkoma Willy Maenhaut Xuguang Chi Wan Wang Nico Raes 《Atmospheric environment (Oxford, England : 1994)》2009,43(3):631-639
Ambient daily PM10 aerosol samples were collected at two sites in Tanzania in May and June 2005 (during the wet season), and their chemical characteristics were studied. The sites were a rural site in Morogoro and an urban kerbside site in Dar es Salaam. A Gent PM10 stacked filter unit sampler with sequential Nuclepore polycarbonate filters, providing fine and coarse size fractions, and a PM10 sampler with quartz fibre filters were deployed. Parallel collections of 24 h were made with the two samplers and the number of these collections was 13 in Morogoro and 16 in Dar es Salaam. The average mass concentration of PM10 was 27 ± 11 μg/m3 in Morogoro and 51 ± 21 μg/m3 in Dar es Salaam. In Morogoro, the mean concentrations of organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were 6.8, 0.51, and 2.8 μg/m3, respectively. In contrast, higher mean concentrations (11.9, 4.6, and 3.3 μg/m3, respectively) were obtained for Dar es Salaam. At both sites, species and elements, such as black carbon, NH4+, non-sea-salt SO42?, K, and Ni (and at Dar es Salaam also V, As, Br, and Pb) were mainly present in the fine size fraction. The common crustal and sea-salt elements, including Na, Mg, Al, Si, Cl, Ca, Ti, Mn, Fe, and Sr, and also NO3? and P (and to a lesser extent Cu and Zn) were concentrated in the coarse particles. Aerosol chemical mass closure indicated that the PM10 mass in Morogoro consisted, on average, of 48% organic matter (OM), 44% crustal matter, 4% sea salt, and 2% EC, while in Dar es Salaam OM, crustal matter, sea salt, and EC represented 37%, 32%, 9%, and 9% of the PM10 mass. The contributions of the secondary inorganic aerosol (non-sea-salt sulphate, nitrate, and ammonium) were small, i.e., only 5% in total at each site. Carbonaceous materials and crustal matter were thus the most important components of the PM10 mass. It is suggested that biomass burning is a major contributor to the OM; at Dar es Salaam there is also a very substantial contribution from traffic. A source apportionment calculation indicated that 68% of the OC at this site originated from traffic exhaust versus 32% from charcoal burning. The crustal matter at Morogoro is likely mainly attributable to soil dust resuspension, whereas in Dar es Salaam it is likely mostly resuspended road dust. 相似文献
42.
叙述了RF内星轮塑性变形的工艺分析,提出了RF内星轮制造的(闭式)精密温锻工艺,阐明了新技术取代旧工艺的优点. 相似文献
43.
全烧垃圾流化床炉飞灰制备免烧砖的性能研究 总被引:3,自引:0,他引:3
开展了水泥固化全烧垃圾循环流化床焚烧炉飞灰特性及其制备免烧砖的研究.同时,分析了飞灰的特性,研究了水泥用量对砖体抗压强度和重金属浸出毒性的影响,并对固化前后飞灰在不同p H值溶液环境下的重金属渗滤特性和基于改进RCR连续提取法的重金属形态分布进行了对比研究.结果表明:飞灰中Cd、Cu、Pb、Ni的浸出浓度分别达到1.76、60.29、5.36、1.48 mg·L-1,远超出生活垃圾填埋标准的规定,Cd、Zn、Cu的酸可交换态部分很高,分别为48%、21.26%、20.72%.水泥基材具有良好的稳定效果,添加量达到30%时,免烧砖中重金属的浸出毒性已远低于标准值.随着水泥掺量的提高,免烧砖的抗压强度呈上升趋势,当水泥比例为30%时,强度可达到12.8 MPa,35%水泥比例的砖体,其抗压强度则达到国标建筑用砖的MU15级.与原始飞灰相比,砖体中重金属在不同渗滤液p H下的浸出趋势并未改变,浸出量却显著下降,p H的适应范围变宽.另外,重金属中酸可交换态部分降至低于1%,主要转变成了可还原态,对环境的污染风险大幅降低. 相似文献
44.
45.
为了提高实际污水处理工艺中除磷效率,优化系统中厌氧释磷的条件,主要研究了三种不同原水投加方式对厌氧释磷过程的影响。本试验采用UniFed SBR系统内的活性污泥,考察了实际生活污水对活性污泥的释磷影响,采用1次进水、4次进水和连续进水3种不同原水供给方式对于厌氧释磷性能进行比较。研究结果表明,不同进水方式可有效延长实际生活污水的注入时间,大大提高其中有机底物的可利用性,释磷速率由0.082增至0.143 mg/(L.min),其中单位活性污泥释磷量分别为2.24×10-3、3.26×10-3和3.80×10-3mg/mg,这种碳源投加方式的改变,使得利用实际生活污水的厌氧释磷特性得到优化,并提高了实际生活污水中有机碳源的可利用性和除磷效率。 相似文献
46.
47.
染料废水处理的有效工艺 总被引:4,自引:0,他引:4
为解决染料废水的治理问题,在工艺试验研究的基础上,成功的采用了“预处理-电化学还原-混凝沉淀-厌氧-=接触氧化”工艺,并设计出一套处理能力为80m^2/d的工艺,经运行检测各项指标均达到国家二级排放标准,其中CODcr、色度、硝基苯、苯胺类的去除率分别为99.2%、99.99%、99.9%、99.35。经过运行证帝该工艺性能稳定、操作简单、投资省、运转成本低易行管理。 相似文献
48.
医疗废物典型组分在回转窑内的热解-气化研究 总被引:4,自引:0,他引:4
在小型回转窑上对模拟医疗废物的4种典型组分进行了批量热解-气化试验.实验结果表明,热解-气化反应物料的转化率较高(80%~100%),基本上随热解-气化终温(FPT)的升高而升高.热解-气化反应中物料的热裂解反应在30min以内基本结束.FPT的升高,有利于挥发分的析出、减少残渣量和处置时间.从试验结果来看,第一段初级处理中采用约700℃的回转窑反应温度比较适合实现医疗垃圾的完全热解和气化. 相似文献
49.
Xuguang TANG Shuying WANG Yongzhen PENG 《Frontiers of Environmental Science & Engineering in China》2010,4(4):475-481
The characteristic of phosphorus removal and appropriate change of the traditional operation modes were investigated in UniFed
sequencing batch reactor (SBR) laboratory-scale apparatus (40 L), treating actual domestic wastewater with low ratios of C/N
(2.57) and C/P (30.18), providing theoretical basis for actual application of wastewater treatment plant. UniFed SBR system
with its unique operation mode had the distinct superiority of phosphorus removal. On this occasion, the effect of volumetric
exchange ratio (VER) and the method of influent introduction for phosphorus removal were studied. When the carbon source became
the limiting factor to phosphorus release, the higher the VER, the lower the phosphorus concentration in the effluent. Three
different influent patterns, including one-time filling, four-time filling, and continuous filling with the same quantity
of wastewater could increase the release rate of anaerobic phosphorus from 0.082 to 0.143 mg·P·(L·min)−1. Appropriate change of the traditional operation modes could optimize the efficiency of phosphorus removal. When the feed/
decant time was extended from 2 h to 4 h, the phosphorous removal efficiency increased from 59.93% to 88.45% without any external
carbon source. In the mode of alternation of anoxic-aerobic (A/O) condition, phosphorous removal efficiency increased from
55.07% to 72.27% clearly. The carbon source in the influent can be used adequately, and denitrifying phosphorus removal was
carried out in anoxic stage 2 (A2). This mode was optimal for the treatment of actual domestic wastewater with low C/N and
C/P ratios. 相似文献
50.
为了给出更符合工程实际的冻土边坡稳定性计算方法,通过考察青藏高原地区多年冻土边坡滑移实例、分析其破坏类型和影响因素,提出了高陡边坡的冻融折线型滑移面,基于热平衡理论和莫尔-库伦强度理论给出了折线型的滑移面确定方法;考虑土体在冻融循环作用下抗剪强度损伤、滑移面上水的渗流作用以及气温变暖三种因素,给出了框架锚杆支护多年冻土区高陡边坡的稳定性计算方法。算例分析表明:利用直线型滑面计算的多年冻土边坡稳定性系数比折线型滑移面更小,容易造成保守设计,使用折线型滑移面更为经济;边坡开挖后10a内,冻融循环作用对稳定性的发展趋势起主导作用,10a后气温变暖发挥主要作用,渗流作用对边坡稳定性的影响较为显著,对稳定性发展趋势没有影响,但三种因素都应当在工程设计中考虑。 相似文献