Perovskite materials for highly efficient catalytic CH4 fuel reforming in solid oxide fuel cell

SOFC (solid oxide fuel cell, SOFC) is recognized to be efficient green energy technology in the 21st century. However, when hydrocarbons are directly used as fuel, carbon deposition is easy to occur in Ni-based anode, thus losing electrochemical catalytic activity. Fuel pre-reforming is also called on-cell reforming of hydrocarbons, which has been a promising solution for alleviating the carbon deposition problem in cermet anodes to varying degrees. And the key factor is to find an efficient and stable fuel reforming catalyst. Perovskite oxides have stable structure, highly catalytic activity and adjustable thermal expansion coefficient for using on the cells, showing great potentials of application for fuel reforming. In this paper, we summarize the application of perovskite catalyst in CH₄ fuel reforming based on the research of our group and other scholars, and puts forward the corresponding views and perspective, especially in perovskite catalyst with Ni exsolution.     

堆料机防撒煤技术的研究与实践

堆料机工作中,由于皮带倾斜的变坡点角度大、皮带回转路线长、落煤点位置高等原因,造成皮带尾部撒煤多,既造成污染,还造成了浪费.经对现场实际勘察、深入分析堆料机的撒煤原因,进行了堆料机的改造实践,取得了良好的应用效果.     

几种碳酸钙对给水用硬PVC管材性能的影响

研究几种PVC常用的碳酸钙物理形貌及其对给水用硬PVC管材性能的影响。研究证明重钙在PVC颗粒上的吸附能力较轻钙差,轻钙颗粒越细,越易被PVC颗粒吸附,干混料的流动性越好;几种碳酸钙中,使用纳米钙的给水用硬PVC管材的冲击强度最高,重钙的最低;加不同碳酸钙的给水用硬PVC管材的密度和维卡软化温度相近。     

Research on the effect of Reynolds correlation in natural convection film condensation

Film condensation is a vital phenomenon in the nuclear engineering applications,such as the gas-steam pressurizer design,and heat removing on containment in the case of postulated accident.Reynolds number in film condensation can be calculated from either the mass relation or the energy relation,but few researches have distinguished the difference between them at present.This paper studies the effect of Reynolds correlation in the natural convection film condensation on the outer tube.The general forms of the heat transfer coefficient correlation of film condensation are developed in different flow regimes.By simultaneously solving a set of the heat transfer coefficient correlations with Remass and Reenergy,the general expressions for Remass and Reenergy and the relation between the corresponding heat transfer coefficients are obtained.In the laminar and wavefree flow regime,Remass and Reenergy are equivalent,while in the laminar and wavy flow regime,Remass is much smaller than Reenergy,and the deviation of the corresponding average heat transfer coefficients is about 30％ at the maximum.In the turbulent flow regime,the relation of Remass and Reenergy is greatly influenced by Prandtl number.The relative deviation of their average heat transfer coefficients is the nonlinear function of Reynolds number and Prandtl number.Compared with experimental results,the heat transfer coefficient calculated from Reenergy is more accurate.     

河流流域及山地项目工程设计探究

结合广州从化温泉养生谷商务会议区施工图设计,从场地防洪设计、道路交通分析、竖向规划控制、工程管线综合4个方面进行具体论述,对规划方案落实到施工图过程中起制约作用的环节进行控制,较好地解决了项目推进中遇到的因一系列不利条件带来的技术难题。     

Application of MIVM for Pb-Sn System in Vacuum Distillation

The activity coefficients of components of the Pb-Sn binary alloy system were calculated based on the molecular interaction volume model (MIVM). A significant advantage of this model lies in its ability to predict the thermodynamic properties of liquid alloys using only two binary infinite activity coefficients. Based on the MIVM, the vapor-liquid phase equilibrium of the Pb-Sn alloy system in vacuum distillation has been predicted using the activity coefficients of Pb and Sn. The results showed that the content of tin in the vapor phase was 0.008?wt?pct, while in the liquid phase, it was 83?wt?pct at 1173?K (900?°C); it reached 0.022?wt?pct in the vapor phase, while in the liquid phase, it was 92?wt?pct at 1223?K (950?°C); and it was 0.052?wt?pct in the vapor phase, while in the liquid phase, it was 97.88?wt?pct at 1273?K (1000?°C). The content of tin in the vapor phase increased with the distillation temperature increasing. Experimental investigations into the separation of Pb and Sn from the Pb-Sn alloy by vacuum distillation were carried out for the proper interpretation of the results of the model. The influence of the distillation time (20 to 80?minutes) and the distillation temperatures of 1173?K, 1223?K, and 1273?K (900?°C, 950?°C, and 1000?°C) on the separating effect was also studied. The experimental results showed that the content of tin in the vapor phase was 0.085?wt?pct, while in liquid phase, it was 83?wt?pct under the operational conditions of distillation temperature of 1173?K (900?°C), evaporation time of 20?minutes, and chamber pressure of 20?Pa; it reached 0.18?wt?pct in the vapor phase, while in the liquid phase, it was 92?wt?pct at 1223?K (950?°C), 20?minutes, and 20?Pa; and it was 0.35?wt?pct in the vapor phase, while in the liquid phase, it was 97.88?wt?pct at 1273?K (1000?°C), 20?minutes, and 20?Pa. In all these experiments, it was observed that the content of tin in the vapor phase increased as the distillation time and temperatures were increased. The experimental results are in good agreement with the predicted values of the MIVM for the Pb-Sn binary system.     

Single-step assembly of polymer-lipid hybrid nanoparticles for mitomycin C delivery

Mitomycin C is one of the most effective chemotherapeutic agents for a wide spectrum of cancers, but its clinical use is still hindered by the mitomycin C (MMC) delivery systems. In this study, the MMC-loaded polymer-lipid hybrid nanoparticles (NPs) were prepared by a single-step assembly (ACS Nano 2012, 6:4955 to 4965) of MMC-soybean phosphatidyhlcholine (SPC) complex (Mol. Pharmaceutics 2013, 10:90 to 101) and biodegradable polylactic acid (PLA) polymers for intravenous MMC delivery. The advantage of the MMC-SPC complex on the polymer-lipid hybrid NPs was that MMC-SPC was used as a structural element to offer the integrity of the hybrid NPs, served as a drug preparation to increase the effectiveness and safety and control the release of MMC, and acted as an emulsifier to facilitate and stabilize the formation. Compared to the PLA NPs/MMC, the PLA NPs/MMC-SPC showed a significant accumulation of MMC in the nuclei as the action site of MMC. The PLA NPs/MMC-SPC also exhibited a significantly higher anticancer effect compared to the PLA NPs/MMC or free MMC injection in vitro and in vivo. These results suggested that the MMC-loaded polymer-lipid hybrid NPs might be useful and efficient drug delivery systems for widening the therapeutic window of MMC and bringing the clinical use of MMC one step closer to reality.     

随机截尾机电设备三参数威布尔分布模型及其应用研究

针对某型飞机机电设备故障率较高的实际问题,提出首先采用平均秩次法进行故障数据预处理,其次假设数据服从三参数威布尔分布并采用相关系数优化法和最小二乘法相结合求得相关参数,最后采用K-S检验法和蒙特卡洛仿真模拟,对可靠性评估结果进行了检验.通过实例验证得出,提出的模型可以准确地描述机电设备在实际使用环境中的故障情况,计算过程简单,便于编程实现.     

Applied electric field on the reaction between submerged entry nozzle and alloy in the steel

In this study, the reactivity between nozzle and submerged entry nozzle and alloy elements in the steel (Al and Ce) under different electric field conditions was investigated. The results show that the decarburization of the nozzle is an important factor affecting the clogging behavior and steel quality. The external electric field directly affects and changes the decarburization, clogging, and reaction behavior between the nozzle and alloy in the steel. If the chemical reaction force between alloys and the nozzle is greater than the applied electric field force in actuality, the clogging will also occur on the submerged entry nozzle. In the future, this new method of controlling and changing the interfacial electric fields can be used to solve the problem of decarburization and clogging of the submerged entry nozzle.