基于热爆炸理论的煤燃点确定及动力学分析

为准确判断煤燃点,提高煤自燃灾害防治能力,依据热爆炸理论,结合煤自燃过程放热曲线,将煤自燃升温过程中微分热流曲线上第1处极小值点作为煤的燃点,计算煤着火前后放热过程动力学参数变化.结果表明:随升温速率增加,煤自燃反应放热过程逐渐向高温区域移动,煤燃点逐渐增大,反应的活化能逐渐减小;同一升温速率下燃点之后煤的活化能增大;...     

环球扫描

美国再投4800万助推环保汽车发展 为提高燃油效率、降低交通成本、保护环境,美国政府将再次投入4800万美元资金,对38个汽车技术研发项目进行支持。美国能源部长欧内斯特·莫尼兹表示,通过与大学、私营企业、国家实验室合作,美国能源部致力于建设强大的交通运输部门,此举不仅削减有害排放,创造就业机会,还有助于美国走向可持续的能源未来。     

环球扫描

北京对本国污染企业采取强硬态度中国当局已命令一些大型污染企业停止所有新项目,以迫使他们立即采取行动达到环保方面的标准。这些企业包括中国六家最大的电力集团中的四家。这一命令下达前,政府承认未能实现去年制定的节约能源和控制污染目标。去年上半年,中国单位国内生产总值(GDP)的能源消耗增长了0．8％。现在,中国的环保机构发起了一场前所未有的行动。除了对电力工业实行严格的控制之外,国家环保总局已停止批准四个工业城市除循环经济类项目外的所有项目。这四个城市分别是河北省的唐山市、山西省的吕梁市、贵州省的六盘水市和山东省的莱芜市。虽然政府出台了一系列新政策,把官员的仕途与他们在节能方面取得的成绩联系起来,但由于多年来一直提倡不惜一切代价发展经济,北京现在仍然不得不努力改变地方官员的态度。专家们说,中国需要改变传统的由上至下的管理方式,目前看,地方官员不会理会中央政府命令。     

环球扫描

企业在行动,政府怎么办？;阿尔·戈尔最后的诱惑;“风”行天下;美国态度突变 环保分子不买账;徐守盛：完不成节能减排任务我就引咎辞职;     

不同生长期的Pseudomonas putida 5-x细胞对工业废水中Cu2+的吸附

研究了不同生长阶段的Cu^2 吸附细菌Pseudomonas-putida5-x对Cu^2 的吸附容量。结果表明在低硫培养基中，当P.putida 5-x细胞生长刚进入对数生长期时，单位细胞对Cu^2 的吸附溶量最低。而当生长进入稳定生长期的后期或死亡期的早期时，单位细胞对Cu^2 的吸附量最大。实验结果还表明，高浓度的Cu^2 对对数期细胞的吸附能力有一定的抑制，而对死亡期的细胞影响较小。早期 研究已证明细胞对重金属离子的吸附和细胞表面某些对重金属离子具有亲和性的功能基团（如某些膜蛋白及羰基化合物）有关。利用透视电子显微镜观察了不同生长阶段的细胞表面结构及对铜离子的吸附效果，发现生长后期细胞表面吸附有较多的Cu^2 ，这表明生长后期的细胞表面可能含有较多的这类功能基团。     

网络版论文摘要

正纳米TiO2电极的制备及电化学降解邻硝基苯酚张平解慧玲杨周生(安徽师范大学环境科学与工程学院,安徽芜湖241003)采用阳极氧化技术在钛片表面制备出纳米TiO2,并通过扫描电子显微镜(SEM)对其进行表征。利用制备的Ti/TiO2电极作为阳极、以Pt丝电极作为阴极,电化学降解邻硝基苯酚。使用紫外—可见光谱和液相色谱技术,对降解     

Trace metals in atmospheric fine particles in one industrial urban city: Spatial variations, sources, and health implications

Trace metals in PM2.5were measured at one industrial site and one urban site during September, 2010 in Ji'nan, eastern China. Individual aerosol particles and PM2.5samples were collected concurrently at both sites. Mass concentrations of eleven trace metals(i.e., Al, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Ba, and Pb) and one metalloid(i.e., As) were measured by inductively coupled plasma atomic emission spectroscopy(ICP-AES). The result shows that mass concentrations of PM2.5(130 μg/m3) and trace metals(4.03 μg/m3) at the industrial site were 1.3 times and 1.7 times higher than those at the urban site, respectively, indicating that industrial activities nearby the city can emit trace metals into the surrounding atmosphere. Fe concentrations were the highest among all the measured trace metals at both sites, with concentrations of 1.04 μg/m3at the urban site and 2.41 μg/m3at the industrial site, respectively. In addition, Pb showed the highest enrichment factors at both sites, suggesting the emissions from anthropogenic activities existed around the city. Correlation coefcient analysis and principal component analysis revealed that Cu, Fe, Mn, Pb, and Zn were originated from vehicular trafc and industrial emissions at both sites; As, Cr, and part of Pb from coal-fired power plant; Ba and Ti from natural soil. Based on the transmission electron microscopy analysis, we found that most of the trace metals were internally mixed with secondary sulfate/organic particles. These internally mixed trace metals in the urban air may have diferent toxic abilities compared with externally mixed trace metals.     

Size, composition, and mixing state of individual aerosol particles in a South China coastal city

Aerosol samples were collected in summer in Macao,a coastal city of the Pearl River Delta Region in China.Morphology,size,elemental composition,and mixing state of individual aerosol particles were determined by scanning electron microscopy coupled energy dispersive X-ray(SEM/EDX) and transmission electron microscopy(TEM).Based on the morphologies of 5711 aerosol particles,they consist of soot(32%),mineral(17%),secondary(22%),and unknown fine particles(29%).The sizes of these particles were mostly distributed between 0.1 and 0.4 μm.Compositions of 202 mineral particles were obtained by SEM/EDX.Mineral particles were mainly classified into three types:Si-rich,Ca-rich,and Na-rich.The compositions of typical mineral particles can indicate their sources in sampling location.For example,mineral particles,collected along the main street,were associated with trace amounts of heavy metals,such as Zn,Ti,Mn,Ba,Pb,and As.TEM observations indicate that most Na-rich particles were aged sea salt particles(e.g.,Na2SO4 and NaNO3) which formed through heterogeneous chemical reactions between sea salt and acidic gases.Additionally,aging time of soot was short in Macao due to high humidity,high temperature,and high levels of sunlight in Macao.Most of soot and fine mineral dust particles were internally mixed with secondary particles.     

1~3 nm颗粒物在粒径分布测量仪中的通过效率研究

基于二甘醇的扫描电迁移率粒径谱仪(DEG-SMPS)是常用的1～3 nm颗粒物粒径分布测量系统.目前对1～3 nm颗粒物在该系统中通过效率的量化不够准确,这给大气颗粒物粒径分布的测量带来了较大的不确定性.本文研究了1～3 nm颗粒物和离子在直管、弯管以及气溶胶中和器等系统组件中的通过效率,并使用等效管长法来量化颗粒物在这些组件单元中的通过效率.研究表明,1～3 nm颗粒物在直管内的通过效率不受颗粒物电性影响,且可以由Gormley-Kennedy (G-K)方程估算.当采样流量为2.5 L·min~(-1)时,DEG-SMPS系统中总等效管长约为433 cm,其中气溶胶中和器的等效管长为160 cm,弯头的等效管长为33 cm.