电除尘器电源交流分量对PM_(2.5)等细微颗粒物除尘效率的影响

除尘器对颗粒物的除尘效率与颗粒物的荷电量密切相关,PM2.5等细小颗粒物由于其荷电量不足而导致其吸收效率较低,对环境造成危害。为了增加粒子的荷电量,以粒子荷电原理为理论依据,从离子电流密度和通过电凝并扩大尘粒中位径2个方面研究了电除尘电源中交流电压分量对PM2.5等细小颗粒物荷电特性的影响,得出了电除尘器电源中交流电压分量可从以上2个方面提高装置对PM2.5等微小颗粒物的荷电量,且频率越高,幅值越大,荷电效果越好,从而可以提高装置对细小颗粒物的除尘效率。     

不同类型农户农地投入的影响因素

农户作为农业生产投入的微观主体,其农地投入行为对农业和农村经济发展影响重大.本文以湖北省江汉平原和鄂北岗地6个县(市、区)的473个农户抽样调查数据,构建逐步回归模型,分析不同类型的农户农地投入行为的影响因素.结果表明:①近年来,农户耕地的投入水平处于上升趋势,国家实施的惠农政策取得了积极成效;②相对于消费型农户而言,利润型农户的总投入水平较离;③目前农户农地投入主要是流动资本投入,固定资本投入较少,农业污染较为严重,农业机械化水平有较大的提升空间;④农户农业生产目标决定其农地投入行为:消费型农户与市场联系不太紧密,依据家庭消费需求进行生产投入决策;利润型农户与市场联系非常紧密,追求利润最大化,按照市场行情进行生产投入决策.⑤不同类型农户农地投入的影响因素存在差异:家庭特征和家庭资源禀赋是影响消费型农户农地投入的主要因素;农业生产要素市场、农产品市场和农业政策是影响利润型农户农地投入的主要因素.     

城镇居民生活能耗与碳排放动态特征分析

居民家庭生活能源消费与碳排放越来越不容忽视,开展这方面研究对于促进居民可持续消费、寻找新的节能减排途径都具有十分重要的意义.本文在考察量化1999-2007年中国城镇居民生活直接、间接能源消费及其碳排放连续变化的基础上,探究了这段时期生活能耗与碳排放的动态变化特征,并分析其潜在的影响因素.研究主要结论包括:1999-2007年,中国城镇居民人均生活总能耗和碳排总量都呈现出逐年增加趋势,其中间接能耗与碳排始终大于直接能耗与碳排,但二者的差异正在逐年缩小;对于人均直接能耗与碳排来说,二者总量都呈逐年增加趋势,其中电力和煤炭是最主要的直接能源消费品种,也是最主要的碳排来源;对于人均间接能耗与碳排来说,虽然居民生活消费开支逐年递增,但由于各类消费项的单位产值能源强度在逐年下降,因此总的间接能耗与碳排并没呈现出一定的递增或递减趋势,而是出现波动性变化.其中"食品"、"教育文化娱乐服务"和"居住"3项是居民生活间接能耗与碳排的主要来源;人均住宅建筑面积是居民生活碳排变化的主要影晌因子.研究结论为引导可持续的家庭消费模式和节能减排措施的制定提供管理启示与科学依据.     

Identification of magnetic particulates in road dust accumulated on roadside snow using magnetic, geochemical and micro-morphological analyses

The aim of this study is to test the applicability of snow surveying in the collection and detailed characterization of vehicle-derived magnetic particles. Road dust extracted from snow, collected near a busy urban highway and a low traffic road in a rural environment (southern Finland), was studied using magnetic, geochemical and micro-morphological analyses. Significant differences in horizontal distribution of mass specific magnetic susceptibility (χ) were noticed for both roads. Multi-domain (MD) magnetite was identified as the primary magnetic mineral. Scanning electron microscope (SEM) analyses of road dust from both roads revealed: (1) angular-shaped particles (diameter ∼1-300 μm) mostly composed of Fe, Cr and Ni, derived from circulation of motor vehicles and (2) iron-rich spherules (d ∼ 2-70 μm). Tungsten-rich particles (d < 2 μm), derived from tyre stud abrasion were also identified. Additionally, a decreasing trend in χ and selected trace elements was observed with increasing distance from the road edge.     

固定床中粒状脱硫剂除尘效率的研究

建立了非稳态过滤下的固定床颗粒层除尘效率模型.该模型尽可能地包含了影响固定床颗粒层除尘的参数,反映了沉积粉尘对除尘效率的影响;研究了以粒状脱硫剂为滤料的固定床在不同颗粒层厚度、空床气速、粒径下的除尘效率.结果表明,在颗粒层厚度为400～800 cm、空床气速≤0.4 m/s的条件下,颗粒层的除尘效率可达90％以上.     

防风抑尘网设计要点及参数的确定

介绍了堆场起尘、防风抑尘网抑尘的机理和国内外防风抑尘网研究结果,结合实际工程设计的经验,分析了防风抑尘网设计要点和主要参数,提出防风抑尘网设计的意见和建议。     

基于工业以太网的烟粉尘在线监测系统的研究

为实现工厂矿山的烟粉尘浓度的实时在线监测,提出了在废气排放监测装置中引入工业以太网技术。以嵌入式S3C2410芯片为核心,扩展相应的外围电路,实现对废气中烟粉尘浓度等参数监测功能,集显示、信息处理、监测和通讯等功能于一体。文章给出了烟粉尘浓度的采样原理和系统的软硬件设计方案,详细给出了以太网控制芯片CS8900A与ARM硬件接口方法与软件实现方案。     

CO_2 Emission Induced by Urban Household Consumption in China

Household consumption is one of the important factors that induce COL emission. Based on input-output model, this article calculated the intensity of CO2 emission of different income groups and seven provinces in China, and then estimated total CO2 emission induced by urban household consumption from 1995 to 2004 in China based on statistic data of household living expenditure. The results show that CO2 emission per capita induced by household consumption had increased from 1583 to 2498 kg CO2 during 1995-2004. The ratio of consumption-induced CO2 emission to total CO2 emission had risen from 19% to 30% in the past decade. Indirect CO2 emission accounted for an important part of the consumption-induced emission, the ratio of indirect emission to consumption-induced emission had risen from 69% to 79% during the same period. A significant difference in consumption-induced CO2 emission across different income groups and different regions has been observed. COs emission per capita of higher income groups and developed regions increased faster than that of lower income groups and developing regions. Changing lifestyle has driven significant increase in CO2 emission. Especially, increases in private transport expenditure （for example, vehicle expenditure） and house building expenditure are key driving factors of growth in consumption-induced COL emission. There are big differences in the amount of CO2 emission induced by change in lifestyle across different income groups and provinces. It can be expected that lower income households and developing regions will increase consumption to improve their livings with income growth in the future, which may induce much more CO2 emission. A reasonable level of CO2 emission is necessary to satisfy human needs and to improve living standard, but a noticeable fact is that CO2 emission per capita induced by household consumption in developed areas of China had reached a quite high level. Adjustment in lifestyle towards a low-carbon society is in urgent need.     

电袋复合除尘器的滤料试验与应用

清灰周期与阻力是除尘器的主要技术性能指标。本文研究了粉尘浓度及荷电粉尘对清灰周期与阻力的影响,总结了影响电袋复合除尘器性能的主要因素,介绍了电袋复合除尘器的应用实例,并分析了电袋复合除尘器的适用性。     

废钢铁切割加工烟尘的治理

介绍了氧-乙炔火焰切割加工废钢铁产生的烟尘治理系统的设计和系统设备选型,重点介绍了烟尘捕集罩的设计和除尘器、电磁脉冲阀、风机的选型和PLC自动控制以及系统实际运行效果,为废钢铁加工企业治理污染提供一套简单、经济、实用的除尘系统作参考.