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1.
The thickness and the porosity of a deposit during ultrafiltration experiments are determined using an electrochemical method. Twenty microelectrodes are mounted flush to a ceramic plane membrane and maps of deposit thickness are determined for three inlet/outlet distributors configurations. Combining an electrochemical method and a step transient method, the determination of the thickness and the porosity of a particles deposit is performed. These local thickness and porosity values are analyzed thanks to wall shear stress local measurements obtained in a previous work [Sep. Sci. Technol. 37 (10) (2002) 2251]. The results emphasize the heterogeneity of the deposit thickness, especially in zones of low wall shear stress. Furthermore, the porosity values of the deposit are ranged between 0.3 and 0.8 as a function of the location at the membrane surface. 相似文献
2.
用NaOH溶液吸收法研究了ZnNiZSM-5芳构化催化剂的积炭量,用色谱纯二氧化碳考察了此方法的准确度.用热失重法确定了烧炭的最佳温度为570℃,根据实验确定了烧炭时间为7h,空气流量为120mL/min.采用正交实验设计法对影响芳构化催化剂积炭量的温度、空速、高径比进行了研究.通过实验结果可知,积炭量最少的最佳工艺条件是温度为560℃,空速为1. 5h-1,高径比为6.1. 相似文献
3.
论中国海洋砂矿床类型 总被引:1,自引:0,他引:1
阮汀 《宁波大学学报(理工版)》1988,(2)
本文总结了作者二十多年砂矿工作的经验,搜集了国内近三百处海洋砂矿床(点)五十余种矿床类型划分的资料,比照国外同类型矿床,结合我国矿床特征,提出了新的海洋砂矿分类原则,矿床工业类型、成因-形态类型、成矿时代类型和保存类型等的划分系统,以及今后的找矿方向。 相似文献
4.
本文综合叙述了对石油或天然气资源量的估计及验证方法,并且提出了在经济效益最佳的前提下,如何求出令后几年的年发现率R1(I)。 相似文献
5.
本文主要应用统计学方法对由问卷调查所获得的我国某地区居民购买地下六合彩活动的信息进行分析,分别对购买者的结构,经济状况及收益进行分析,指出地下六合彩的本质及这一现象给我们的警示.同时通过分析一个消费者个体的消费模型给出消费者如何理性消费的建议. 相似文献
6.
以苯-乙醇为溶剂,在对煤气管道沉积物提取,分离后,采用25m*0.24mmI.D.的石英毛细管OV-101柱进行了GC,GC-MS分析,鉴定出19种有机成分,并用归一法作了定量分析,并用采用IR、点滴试验等方法对其无机物作了定性鉴定。 相似文献
7.
Traditional researches on metal corrosion under salt solutions deposit conditions are usually carried out by visual, electron microscopic observations and simple electrochemical measurement via a traditional one-piece electrode. These techniques have difficulties in measuring localized corrosion that frequently occur in inhomogeneous media. This paper reports the results from the experiments using specially shaped coupons and a relatively new method of measuring heterogeneous electrochemical processes, namely, the wire beam electrode(WBE). Preliminary results from copper and aluminum corrosion in highly concentrated sodium chloride solutions with and without solid deposits show that the method is useful in simulating and studying corrosion especially localized corrosion in pipelines. 相似文献
8.
《Optimization》2012,61(1-2):151-159
This paper deals with the disclosure of a note-worthy relationship between solutions of variational problems of double integrals and transportation flow problems for two products. It is founded on the duality for transportation flow problems and deposit problems 相似文献
9.
Yashasvi Laxminarayan Peter Arendt Jensen Hao Wu Flemming Jappe Frandsen Bo Sander Peter Glarborg 《Proceedings of the Combustion Institute》2019,37(3):2689-2696
Fly ash deposition on boiler surfaces is a major operational problem encountered in biomass-fired boilers. Understanding deposit formation, and developing modelling tools, will allow improvements in boiler efficiency and availability. In this study, deposit formation of a model biomass ash species (K2Si4O9) on steel tubes, was investigated in a lab-scale Entrained Flow Reactor. K2Si4O9 was injected into the reactor, to form deposits on an air-cooled probe, simulating deposit formation on superheater tubes in boilers. The influence of flue gas temperature (589 – 968°C), probe surface temperature (300 – 550°C), flue gas velocity (0.7 – 3.5?m/s), fly ash flux (10,000 – 40,000?g/m2h), and probe residence time (up to 60?min) was investigated. The results revealed that increasing flue gas temperature and probe surface temperature increased the sticking probability of the fly ash particles, thereby increasing the rate of deposit formation. However, increasing flue gas velocity resulted in a decrease in the deposit formation rate, due to increased particle rebound. Furthermore, the deposit formation rate increased with probe residence time and fly ash flux. Inertial impaction was the primary mechanism of deposit formation, forming deposits only on the upstream side of the steel tube. A mechanistic model was developed for predicting deposit formation in the reactor. Deposit formation by thermophoresis and inertial impaction was incorporated into the model, and the sticking probability of the ash particles was estimated by accounting for energy dissipation due to particle deformation. The model reasonably predicted the influence of flue gas temperature and fly ash flux on the deposit formation rate. 相似文献
10.
Qun-li Rao Gang Bi Qing-hua Lu Hao-wei Wang Xiao-lan Fan 《Applied Surface Science》2005,240(1-4):28-33
An electroless Ni-B film was deposited in natural state of the plating bath. The structure and composition distribution in depth of the film were explored by X-ray diffraction (XRD) and Auger electron spectroscopy (AES) after the deposition. It was found that the film experienced morphologic transformations during the deposition. The morphology of the film varied in-step with its structure and was presumably relevant with the changes of depositing rate. The mechanism that leads to the morphologic transformations has been discussed. 相似文献