氨合成塔触媒升温还原中水汽浓度分析方法改进

采用电石转化氢焰色谱法,用TDX-01固定相为分离柱,分析氨合成塔触媒升温还原中水汽浓度。     

基于BIM数据的建筑抗震弹塑性分析建模技术

针对建筑信息模型(Building Information Model,BIM)的共享数据标准为IFC标准,但现有软件导出的IFC格式模型缺少关键数据,不能满足结构非线性抗震分析数据需求的问题,提出建筑抗震弹塑性分析数据基于IFC标准的表达方法,编写C++转换程序将BIM包含的数据正确地转换成不同软件(如Marc和OpenSees等)的模型,从而可以使用不同的结构分析软件实现建筑抗震弹塑性分析.该方法为基于BIM数据实现建筑抗震弹塑性分析提供参考.     

Catalytic conversion of methane to benzene over Mo/ZSM-5

Dehydroaromatization of methane to benzene occurs over a 2 wt% Mo/ZSM-5 catalyst at 700C under non-oxidizing conditions. Following an initial induction period, during which CH₄ reactant reduces the original Mo⁶⁺ ions in the zeolite to Mo₂C and deposition of coke occurs, a benzene selectivity of 70% at a CH₄ conversion of 8–10% could be sustained for more than 16 h. X-ray photoelectron spectroscopy and X-ray powder diffraction measurements indicate that the reduced Mo is highly dispersed in the channels of the zeolite. Initial activation of CH₄ reactant occurs on Mo₂C sites, leading to the formation of C₂H₄ as the primary product. The latter then undergoes subsequent oligomerization reactions on acidic sites of the zeolite to form aromatic products.     

降低全低变工艺阻力的措施

将变换流程改为全低变工艺后,吨氨蒸汽消耗明显下降,但触媒床层阻力迅速上升.通过采取增设焦炭过滤器、更换触媒、改进蒸汽分布器等一系列措施,不仅保证了正常的生产指标,而且还使变换炉的阻力有了明显下降,取得了满意的效果.     

Kinetic modelling of the catalytic conversion of synthesis gas

A kinetic study for the one-step conversion of synthesis gas to gasoline on a ZnO–Cr₂O₃–ZSM-5 catalyst is described. On this catalyst, three reactions are involved in the overall transformation of synthesis gas: the methanol synthesis, the conversion of methanol to hydrocarbons and the water–gas shift reaction. Under the operating conditions selected for the study, it was found that the water–gas shift was at equilibrium and the methanol was completely converted to hydrocarbons. Consequently, it was postulated that the kinetics of the limiting reaction step, the methanol synthesis on the ZnO–Cr₂O₃ component, was the one that controls the overall reaction rate. Three kinetic model equations describing the rate of synthesis gas conversion on the bifunctional catalyst, were considered to fit the data of the experimental runs performed in a Berty well-mixed reactor. Those equations were derived under very special conditions where the methanol decomposition term could be neglected. It was also observed that in the kinetic equations a term involving the fugacity of CO₂ was required to predict the rate properly. The catalyst deactivation was also taken into account in the analysis.     

快速高效隔膜压滤机在鹤壁四矿选煤厂的应用

介绍了快速高效隔膜压滤机的主要性能参数和特点 ;分析了压滤机在煤泥水处理系统中的应用情况和运行结果 ;应用快速高效隔膜压滤机对煤泥水处理系统进行改造后获得了较好的经济及社会效益     

普钙产品转化率的数值计算方法

对影响普钙产品转化率的各种因素进行了分析,利用MATLAB 软件包得到了转化率的计算公式,提出了确定未分解磷矿的比例和由倍半氧化物引起的有效磷退化幅度的方法,为生产系统的预测和调整提供了一种途径。     

An EM-based identification algorithm for a class of hybrid systems with application to power electronics

In this paper we present an identification algorithm for a class of continuous-time hybrid systems. In such systems, both continuous-time and discrete-time dynamics are involved. We apply the expectation-maximisation algorithm to obtain the maximum likelihood estimate of the parameters of a discrete-time model expressed in incremental form. The main advantage of this approach is that the continuous-time parameters can directly be recovered. The technique is particularly well suited to fast-sampling rates. As an application, we focus on a standard identification problem in power electronics. In this field, our proposed algorithm is of importance since accurate modelling of power converters is required in high- performance applications and for fault diagnosis. As an illustrative example, and to verify the performance of our proposed algorithm, we apply our results to a flying capacitor multicell converter.     

转化乳剂的离子电导和光电导研究

本文研究了ＡｇＢｒＣｌ转化乳剂的离子电导和光电导。随着乳剂中溴含量的增高，其离子电导也随之升高，而光电子寿命则降低。ＡｇＢｒＣｌ乳剂的离子电导主要取决于其组成；ＡｇＢｒＣｌ转化乳剂的光电子寿命主要受隙间银子浓度的影响，隙间银离子浓度越大，光电子寿命越短。     

Free radicals in coal and coal conversions. 8. Experimental determination of conversion in hydroliquefaction

The results of conversion determinations on the products from Powhatan No.5 coal liquefied in an autoclave and in a high-pressure, high-temperature e.s.r. cavity are reported. Oil, asphaltene and preasphaltene yields, and overall conversion have been determined for Powhatan No.5 coal samples liquefied in tetralin, SRC-11 heavy distillate, and naphthalene at temperatures from 400 to 480 ° C in both reactor systems. The concept of reaction severity is introduced and used to formalize the relation between the effect of temperature and reaction time on oil yield and conversion. Oil is the predominant product in liquefaction in tetralin or naphthalene, asphaltene is the major product of liquefaction in SRC-II heavy distillate. Retrogressive reaction (THF-insoluble product formation) becomes severe when SRC-II heavy distillate is the liquefaction solvent and residence time of >10 min are used at temperatures >450 °C. Preasphaltenes appear to be the only intermediate species in Powhatan No.5 liquefaction.