Nanocrystalline CeO2 in SBA-15: Performance of Pt/CeO2/SBA-15 Catalyst for Water-gas-shift Reaction

CeO₂ particles confined within the pores of an SBA-15 mesoporous silica host were prepared by incipient wetness impregnation (IMP) and deposition precipitation (DP) methods. The materials were characterized by XRD, N₂-adsorption and temperature programmed reduction (TPR) to evaluate the structure, texture, and redox properties. The preparation procedure had significant impact on the assembling mode of CeO₂ inside the SBA-15 mesopores. A high dispersion of CeO₂ particles was achieved via DP, whereas the dispersion of CeO₂ prepared by IMP was found to be inhomogeneous and CeO₂ partially blocked the pores. The CO conversion in the water-gas-shift reaction was enhanced over 1 wt% Pt supported on CeO₂-modified SBA-15 obtained by DP.     

Effect of extrusion temperature on elongational flow behavior of PVC melt

The effect of the sample extrusion temperature between 160° and 180°C on the elongational flow properties of a low molecular weight suspension PVC (unplasticized) has been studied with the Rheometrics Extensional Rheometer. The results of both the tensile creep measurements at a constant stress of 24 KPa and the stretching experiment at a constant strain rate of 0.01 sec^?1 indicated the existence of a rheological transition at 185°C marked by the dual valued flow activation energy and also by the temperature dependence of the tensile stress-strain curves. Increasing extrusion temperature increased both the flow activation energy and the extensional viscosity below the transition temperature.     

An Analytical Approach to Creating Multitouch Gesture Vocabularies in Mobile Devices: A Case Study for Mobile Web Browsing Gestures

This study proposes an analytical approach to the creation of multitouch control-gesture vocabularies applicable to mobile devices. The approach consists of four steps: (a) identifying target commands, (b) extracting gesture features of the target commands, (c) analyzing usage patterns based on elements that consist of multitouch gestures, and (d) creating gesture vocabularies based on the gesture features and elements. Usefulness and practicality of the proposed approach were validated in a case study. The case study created 11 mobile web browsing gestures to improve short-cut interactions. Six volunteers created gestures based on systematic procedures and practical methods. A total of 314 gestures were created in the case study, and the results were compared with those of a previous study that used an empirical approach to design control gestures. The proposed approach helped designers to create appropriate gestures for various commands on mobile devices. It was very practicable for all designers, including even novice users.     

基于TCN的地铁列车控制方案的研究

本文针对地铁车厢内控制设备分散的问题,设计了基于TCNRTP的地铁列车控制网络系统。采用NS2网络模拟软件构建的虚拟网络环境,编写消息数据传输层协议,通过测试列控网络的通信效率,得出了影响通信效率的因素;通过配置列控通信设备的基本功能和设定装置运行参数达到配置网络化通信的目的。     

Application of structural curvature of coalbed floor on CBM development in the Zaoyuan block of the southern Qinshui Basin

Based on controls of structural style and the position in coalbed methane(CBM)development,we used a method of curvatures to study its relations with CBM development parameters.We calculated structural curvatures of contours of the No.3coal seam floor of the Shanxi Formation in the Zaoyuan block of the Qinshui Basin and analyzed its relations with development parameters of coalbed methane wells.The results show that structural curvature is negatively related to coal reservoir pressure,while positively related to permeability.With an increase in structural curvature,the average production of coalbed methane wells increases at first and then decreases,reaching the highest production at 0.02 m-1 of structural curvature.Therefore,structural curvature can be an important index for potential evaluation of coalbed methane development and provide a basis for siting coalbed methane wells.     

Fluidized bed combustion of high ash anthracite: Analysis of combustion efficiency and particle size distribution

Fluidized bed combustion of high ash anthracite (HAA) was experimentally studied. The combustor consists of 0.25 m ID bed, and auxiliary equipments for coal feeding, ash removal, lemperature control, etc. Experimental results elucidate main cause of fuel loss to be elutriation of fines (i.e., flyash) containing unburned carbon. However, detailed balances of particle size distribution show majority of carbon in flyash comes from fines contained in the feed instead of attrition of coarse particles. The latter is the main source of flyash for conventional coal. The difference is due to much smaller attrition rate of HAA; feed HAA particles do not shrink much in size by combustion and attrition.     

Robust Control of Networked System and Its Application

International Journal of Control, Automation and Systems - In this paper, the stability issue of networked system with dynamical topology in intelligent vehicle is studied. The systems are...     

Dynamic buffering performance of the honeycomb paperboard filled with polyurethane

A new kind of composite buffering material was made by filling the voids of honeycomb paperboard with polyurethane. Drop tests were performed to evaluate the dynamic energy absorption capacity of the material. Based on the tests results, we analyzed the mechanical behaviors of the material under different conditions and obtained the inherent influencing laws of some factors on the material＇s dynamic buffering performance. It was shown that the dynamic buffering performance varied directly with impact velocity, and inversely with the void diameter, thickness and buffeting area of the composite material.