塑料电除雾器的特性与安全运行对策

介绍了塑料电除雾器性能与构造特点 ,分析了硫酸雾的成因及规律 ,针对塑料电除雾器运行中可能出现的故障提出了保证其高效运行的措施     

SO_3烟气调质对粉尘导电性能的改善机制

以塔山电厂SO3烟气调质运行实测数据为基础条件,通过分析SO3烟气调质后的除尘效率与飞灰比电阻、飞灰粒径、飞灰含湿量等理化性质,揭示SO3烟气调质对燃用高灰分劣质煤电厂除尘性能改善机制。为期一年测试结果表明:调质后比电阻降低3个数量级,2μm以下粒径粉尘比例提高了近6%,含湿量提高14%,从而提高表面导电机制,改善电除尘器电气参数,使电除尘效率由原来98.82%稳定提高至99.91%。     

长株潭城市群地类转移的碳传导效应与预测

土地利用碳排放是影响城市碳达峰、碳中和实现的重要因素.基于土地利用遥感数据和碳排放估算模型,得到长株潭城市群的土地利用碳排放量,借助转移矩阵分析了长株潭城市群土地利用转移的碳传导效应.此外,采用马尔科夫模型预测2030年和2060年的长株潭土地利用碳排放量.结果表明：①1995~2018年长株潭城市群土地利用净碳排放从810.84×10⁴ t增加到2015.41×10⁴ t,碳源/汇比整体呈上升趋势.其中,建设用地是主要的碳排放源,林草地是主要的碳汇.②不同时段地类转移引致的碳传导最终均表现为净碳排放,在时间上呈现先增加后减少的态势.其中以林地和耕地向建设用地转移产生的碳传导最为显著,涉及草地、水域和未利用地的碳传导效应微弱.③预测结果表明,长株潭城市群的土地利用碳排放预测量处于持续上涨态势,如若仍按目前趋势发展,则如期实现"双碳目标"存在难度.政府需要在加强林地的碳吸收能力以提升生态系统碳汇增量和遏制建设用地的无序扩张以减少碳源两方面着力,加快长株潭城市群的绿色低碳建设.上述结果为长株潭城市群开展低碳导向的城市土地利用调控提供了重要参考.     

Nerve conduction studies in sprayers occupationally exposed to mixture of pesticides in a mango plantation at Lucknow,North India

In this study, nerve conduction, organochlorine (OC) pesticide residues in blood and cholinesterase activity levels of pesticide sprayers employed in mango plantations at Lucknow, North India, were determined. Fifty-two sprayers from mango plantations who regularly spray mixture of pesticides like organophosphates (OP), OCs, and carbamates were considered as exposed group. Eighteen subjects with similar socio-economic status of exposed group, who do not handle pesticides, were selected as controls. Questionnaire-based interviews related to personal and occupational histories of the study subjects were carried out. Sprayers did not use any personal protective equipment during pesticide handling. The blood-pesticide analyses of sprayers show higher mean values of hexachlorohexane (HCH), γ-HCH, δ-HCH, total HCH, op-DDT compared with the controls. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activites were significantly reduced among sprayers. Risk of motor nerve conduction deficits was observed in sprayers with low AChE activity. Negative correlation of motor and sensory nerve conduction deficits was observed with the duration of exposure and age among sprayers. The study demonstrated that the prolonged exposure to mixture of pesticides, ergonomic factors, decline in cholinesterase activity may lead to nerve conduction dysfunction. The findings suggest the need for controlled use of pesticides in the plantation and indicated the need for training and implementation of hygiene practices like proper usage of personal protective equipments.     

气候试验需要注意的几个问题

本文对气候试验要注意的几个问题进行探讨,有助于提高试验质量.     

热传导强化气相抽提处理苯系物污染土壤实验

以苯系物(BTEX)污染土壤为研究对象,研究加热源功率和加热时间对土壤苯系物去除率的影响;实验通过分析尾气和冷凝水的污染物浓度来判断实验的终止时间点.结果显示,在3个功率100、200 W和400 W作用下,各污染物的残留浓度较低,所需要的处理时间分别为168.5、122.5 h以及104 h,消耗的总电能分别为:0.49、0.56 KW.h.Kg-1TS以及0.81 kW.h.Kg-1TS.功率越高,土壤中BTEX去除效率越高,同时能耗也越大.实验通过分析处理前后土壤中有机质含量,发现在加热的条件下有机质会逐渐减少,功率越高,有机质去除的速率越快,越有利于污染物的去除.本文的结果可证实通过加热可有效提高土壤中苯系物的气相抽提去除效率,对现场中试的开展提供参数依据.     

浅谈如何选择温湿度箱

主要阐述了电子设备应用于不同场所,遇到的各种复杂的环境因素、;如高温、高湿、低温等,这些环境因素的存在将影响电子信息产品的可靠性,本文简要介绍了如何选用温湿度箱。     

Low-Level Microwave Radiation Effect on Nerve Pulse Conduction Velocity

Summary This study is aimed to investigate dependence of nerve pulse conduction velocity on low-level microwave exposure. The changes in fiber membrane permeability or myelin sheath, caused by microwave, should affect nerve pulse conduction velocity. Experimental investigation was carried out for nerve pulse conduction velocity with and without applied microwave field and different orientations of its polarization to the nerve fiber. Microwave radiation of 450 MHz was applied polarized perpendicular or parallel to the nerve fiber. The measured field power density at the skin was 0.87 mW/cm². Special program was developed for calculation of the nerve pulse conduction velocity in LabView environment. The right nervus medianus motor nerve fibers of 35 young subjects were under the study. The experimental protocol included ten measurements in every cycle of five different exposure conditions. No changes in average values of the conduction velocities discovered in different exposure conditions. Theoretical calculations based on Hodgkin-Huxley model confirm only a weak possible effect. The results showed that low-level microwave radiation did not cause statistically significant change in nerve pulse conduction velocity in human motor nerve fiber.     

油罐火灾沸溢发生时间预测模型

油罐火灾发生沸溢具有很大的危险性,而沸溢时间的准确预测是目前的一个技术难题。笔者结合宽沸程油品油罐火灾沸溢实验,对油层内部传热过程进行详细分析,认为油罐火灾沸溢事故可近似地看作一无内热源、常物性的非稳态传热问题,其过程包含油水界面不参与换热和参与换热的两个阶段。建立了油罐火灾沸溢发生时间预测模型,对两个不同阶段,分别进行理论分析和数值方法进行求解,并同实验数据对比。结论可信,误差较小,为沸溢机理探讨研究和油罐沸溢火灾的扑救提供了参考依据。计算表明:燃烧速度和油罐底部水层厚度对沸溢时间的影响很大,而降低罐壁温度并不能有效地延迟沸溢的发生。     

高梯度磁分离技术在水处理中的应用及发展

高梯度磁分离技术是一种新型的水处理技术,目前已经得到了大量应用,具有广阔的应用前景。本文介绍了它的基本原理,综述了该技术在水处理中的应用现状,并做出了展望。