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1.
Decomposition of dimethyl sulfide （DMS） in air was investigated experimentally by using a wire-cylinder dielectric barrier discharge （DBD） reactor at room temperature and atmospheric pressure. A new type of high pulse voltage source with a thyratron switch and a Blumlein pulse-forming network （BPFN） was adopted in our experiments. The maximum power output of the pulse voltage source and the maximum peak voltage were 1 kW and 100 kV, respectively. The important parameters affecting odor decomposition, including peak voltage, pulse frequency, gas flow rate, initial concentration, and humidity, which influenced the removal efficiency, were investigated. The results showed that DMS could be treated effectively and almost a 100% removal efficiency was achieved at the conditions with an initial concentration of 832 mg/m3 and a gas flow rate of 1000 ml/min. Humidity boosts the removal efficiency and improves the energy yield （EY） greatly. The EY of 832 mg/m3 DMS was 2.87 mg/kJ when the relative humidity was above 30%. In the case of DMS removal, the ozone and nitrogen oxides were observed in the exhaust gas. The carbon and sulfur elements of DMS were mainly converted to carbon dioxide, carbon monoxide and sulfur dioxide. Moreover, sulfur was discovered in the reactor. According to the results, the optimization design for the reactor and the matching of high pulse voltage source can be reckoned. 相似文献
2.
挥发性有机物(VOCs)的污染与控制技术日益受到重视。近年来发展起来的非平衡等离子体技术在治理VOCs方面已初步显示其独特的技术优势,现已成为废气治理研究领域中的前沿热点课题之一。等离子体法降解VOCs的机理较为复杂,研究不同线路对VOCs降解过程的影响意义重大。采用脉冲电晕放电等离子体技术,建立了混合电晕、有机电晕、空气电晕和分别电晕4种不同的实验方案,选取苯为代表物质进行实验研究,在初始浓度、停留时间和电源参数等一定的条件下,考察脉冲电压对苯去除率的影响。结果表明,电压为140kV、混合电晕时苯的去除率达到82.73%,脉冲电晕技术处理低浓度有机废气效果较好。 相似文献
3.
以酿酒酵母(Saccharomyces cerevisiae)为研究对象,研究大气压冷等离子体激活酿酒酵母提高乙醇转化率的工艺条件。在单因素实验基础上,选取等离子体处理时间、等离子体电源电压和处理菌液体积为影响因子,以乙醇转化率为响应值,应用Box-Behnken中心组合实验建立数学模型,进行响应面分析。结果表明,大气压冷等离子体提高乙醇转化率的最佳实验参数为:处理时间1 min,电源电压24 V,处理菌液体积9 mL。在此条件下,乙醇转化率达到0.58 g/g,比未处理过的酿酒酵母发酵葡萄糖生成乙醇的转化率高23.6%。 相似文献
4.
ZHANG Juan CHEN Xue-ming YAO Pei-dong CHEN Guo-hua 《浙江大学学报(A卷英文版)》2007,8(9):1457-1461
Boron-doped diamond （BDD） film electrodes using Ta as substrates were employed for anodic oxidation of salicylic acid （SA）. The effects of operational variables including initial concentration, current density, temperature and pH were examined. The results showed that BDD films deposited on the Ta substrates had high electrocatalytic activity for SA degradation. There was little effect ofpH on SA degradation. The current efficiency （CE） ,aas fbund to be dependent mainly on the initial SA concentration, current density and temperature. Chemical oxygen demand （COD） was reduced from 830 mg/L to 42 mg/L under a current density of200A/m^2 at 30℃. 相似文献
5.
Polyoxymethylene dimethyl ethers(DMM_n) are promising diesel additives. The synthesis of DMM_n from methylal(DMM) and paraformaldehyde over the NKC-9 acidic ion-exchange resin catalyst was investigated. Many unrecyclable by-products such as methyl formate, dimethyl ether and formic acid were produced in the reaction. To increase the selectivity of the desired products DMM_(3-6) and reduce the amount of unrecyclable by-products, the effects of reaction temperature, time, pressure and the molar ratio of the raw materials were evaluated through a series of single factor experiments. Experiments revealed that trace amount of water could suppress the formation of unrecyclable by-products, and the optimum initial water content(less than 2 wt%) was investigated. In addition, the synthetic process needs to go through the polyoxymethylene hemiformals intermediate stage, and then the DMM_n were obtained when polyoxymethylene hemiformals reacted with methanol. Ultimately, a possible mechanism is proposed to describe the formation of DMM_n from polyoxymethylene hemiformals in detail, in which it is revealed that the formation of carbocation intermediates is important in the reaction processes. 相似文献
6.
讨论了完全图Kn分解成四个顶点的星和圈的存在性,给出完全图Kn存在{C4,S4}-强制分解以及完全图Kn存在{C4,S4}-分解的充要条件. 相似文献
7.
采用双室结构研究了不同实验条件下,以天然混合菌接种的微生物燃料电池产电能力.发现在V底物/V菌液=5：1的条件下各电池的电流输出高于2：1条件,提高阴极的密度和强度可增加开路电压,但会降低工作电流的输出.一次性放电实验显示,不同微生物燃料电池产电和电子回收能力差别显著,功率密度变化为196.6-1283.0mW/m2,COD去除率在35.0-47.3%,库仑效率在28-50%,电子回收潜能大.开放性生态系统中的微生物比封闭环境中的微生物催化效果好,未驯化的硫化细菌催化底物产能的效率低. 相似文献
8.
INTRODUCTION Nitrate contamination in groundwater and sur-face water has become an increasingly serious envi-ronmental problem. Anthropogenic sources such asnitrogen fertilizers, animal wastes, and septic systemsaccount for most nitrate contamination of ground-water. Nitrate itself is relatively non-toxic. However,it can be microbially reduced to nitrite, which posesseveral health threats to humans including methemo-glo-binemia, liver damage and cancers. Nitrate out-flow onto shallow cont… 相似文献
9.
低电流密度电解金属钕研究 总被引：6，自引：0，他引：6
本文首次介绍了氟化物熔盐体系中在低阴极、阳极电流密度条件下电解制备稀土金属钕的研究情况.结果表明在阴极电流密度为1.39 A/cm2情况下,电解制备金属钕获得了极高的阴极电流效率,且电解电压仅4.8V左右.该研究为下埋阴极稀土金属熔盐电解槽的研究和设计提供了坚实的理论基础.用数据拟合法得到了电解电压与阴极和阳极电流密度之间以及电流效率与阴极电流密度之间的数学关系式. 相似文献
10.
The simultaneous removal of ethyl acetate, benzene and toluene with relatively low or high initial concentration is studied using a laboratory scale gliding arc gas discharge （GA） reactor. Good decomposition efficiencies are obtained which proves that the GA is effective for the treatment of volatile organic compounds （VOCs） with either low or high concentration. A theoretical decomposition mechanism is proposed based on detection of the species in the plasma region and analysis of the decomposition by-products. This preliminary investigation reveals that the GA has potential to be applied to the treatment of exhaust air during color printing and coating works, by either direct removal or combination with activated carbon adsorption/desorption process. 相似文献
11.
10种金属氧化物对氯酸钾热分解制氧催化效果的研究 总被引：1，自引：0，他引：1
加热KClO3分解制氧常使用MnO2作催化剂。实验发现：CaO，A12O3，CuO，FeO3，TiO2，Nd2O3，PdO2，V2O5，Cr2O39种金属氧化物及无机盐MnSO4，FeCl2，FeCl3，CoCl2，ZnCl2等亦有较好的催化效果，在试剂用量、产氧量、反应速度和控制副反应等方面具有明显的优点。 相似文献
12.
在ECR刻蚀系统中氧等离子体的放电存在两种模式,即微波功率低于500W时的低密度放电和微波功率高于500W时的高密度放电．a—C：F薄膜的刻蚀速率随着氧分压的增加而降低,是由于气压增加时,等离子体的电子温度降低及等离子体鞘电位降低造成．a—C：F薄膜的刻蚀速率随着氧气流量的增加相应地增加,是由于在氧分压保持0．1Pa不变的条件下,氧流量增加使氧原子在真空室的驻留时间变短造成． 相似文献
13.
高校质量监控目标分解过程的“四要”与“四控” 总被引：1，自引：0，他引：1
质量目标是高校教学质量监控体系的核心,其制定、分解、实施是教学质量监控体系发挥质量保障作用的关键。在质量目标分解过程中,要注重与内部沟通、部门间接口、岗位职责、工作任务等相结合,同时要对其分解对象、分解任务、分解步骤的考核与评审工作进行控制。 相似文献
14.
从实时监测电压波动和闪变信号的角度出发,研究了基于小波多分辨率分解的电压闪变分析方法;利用小波变换的多分辨率分析方法,对电压闪变信号进行了检波与分解,并提取出电压波动信号的频率和幅值。从而得到反映电压闪变的参数。 相似文献
15.
EMD方法在局部放电超声信号提取中的应用 总被引：1，自引：0，他引：1
变压器局部放电超声波定位中,首要任务是对超声波信号的提取,其准确性将直接影响到定位的实现.EMD方法可以将非线性、非平稳信号分解为不同频率成分的内禀模态函数,从而提取超声波信号.以山西省高压电气设备局部放电定位项目为背景,详细分析了EMD方法的原理、实现过程,并用实例测试仿真,验证了该方法的有效性与准确性. 相似文献
16.
1IntroductionIn recent years,there are many papers published ontoluene oxidation to benzaldehyde.The most i mpor-tant research works of these papers are electric oxida-tion and toluene oxidizied by using air in gas phase orin liquid phase.A novel technology for benzaldehydeproduction is developed,with which manganese sul-fate reacts with ammonium carbonate to yield manga-nese carbonate and ammoniun sulfate.Manganese car-bonate is baked for being changed into manganese ses-quioxide,which can ox… 相似文献
17.
小波变换在数字图像处理中的应用 总被引：2，自引：0，他引：2
主要分析了基于小波变换的图像分解和图像压缩的技术，并运用Matlab软件对图像进行分解，然后提取其中与原图像近似的低频信息，达到对图像进行压缩的目的．分别作第一层分解和第二层分解，并比较图像压缩的效果。 相似文献
18.
A new supported amorphous catalyst CoP/TiO2 was prepared by chemical reduction and characterized by ICP, XRD, TEM, BET and DSC Its application in decomposing PH3 to high purity phosphor and its catalytic activity were studied. The decomposition rate is over 95% at 450 ℃. For comparison, unsupported CoP amorphous catalyst was prepared by the same method. The result suggests that CoP/TiO2 exhibits higher thermal stability and catalytic activity than CoP, which is attributed to the high dispersion of CoP alloy particles on the support-TiO2. 相似文献
19.
为了研究空芯光纤中氩气的放电特性,利用有限元软件 COMSOL Mutiphysics 基于流体模型对长为50mm 空芯光纤中的气体放电过程进行仿真,得到氩气放电过程中等离子体的主要参数分布,如电子密度、离子密度、电势、空间电荷密度、电场强度等。同时分析了气压对放电过程的影响,结果表明,气压对气体放电的影响主要体现在电子密度与阴极侧的电场强度上,随着气压的逐渐增大,阴极侧的电场强度也随之增加,阴极侧电子密度则保持不变,但在空芯光纤中央区域,电子密度的增大较为明显。 相似文献
20.
针对电动汽车动力锂电池,提出一种能够在恒流及变流放电工况下修正SOC估算误差的方法。首先以双阻容并联网络RC作为锂电池等效电路模型,采用最小二乘法对模型参数进行估计,再依据模型及实验数据构建锂电池非线性状态方程,对锂电池开路电压与SOC的关系进行拟合,最后结合EKF算法与安时积分算法估算锂电池SOC,并采用脉冲放电实验进行验证。实验结果表明,该算法能够在恒流脉冲放电工况下有效修正SOC估算误差,并控制精度在1%以内,且在变流工况下仍可修正SOC初始误差。 相似文献