掘进机内喷雾系统技术研究

文章通过对潞安环能股份公司常村煤矿掘进机内喷雾系统,在实际应用过程中存在的问题进行分析,对原有悬臂段的水路结构进行技术改造,解决喷雾水因密封失效对悬臂段内轴承带来的损坏,以及造成切割电机进水后跳闸等问题,同时,对改善工作面的喷雾效果和工作面的作业环境具有积极意义。     

SKT-14型数控风阀跳汰机在峻德选煤厂的应用

该文分析了峻德选煤厂使用的LTG-15型筛侧空气室跳汰机存在的问题及将原LTG-15型跳汰机更新为SKT-14型数控风阀跳汰机后各项分选指标,叙述了SKT-14型跳汰机的结构特点及使用后带来的经济效益。     

Power Density and Electrical Efficiency in Closed Cycle MHD Generator with Fully Ionized Seed

Effects of a reduced seed concentration on performances of a nonequilibrium MHD generator are investigated by calculating power densities and electrical efficiencies for both Faraday and Hall generators.

It is shown that high electrical efficiencies and high power densities are obtained simultaneously by suppressing the ionization instability with reduced seed fractions (10^?4 ～10^?5) when values of the effective electrical conductivity and the effective Hall parameter recover to above 50% of their ideal ones. Results also indicate that argon is more suitable for a working fluid than helium in the case of a reduced seed concentration.     

放射性气溶胶冲击式采样器的设计与研究

为了提高冲击式采样器的捕集效率,以放射性气溶胶采样器为研究对象,利用斯托克原理计算冲击板的各个参数,并采用CFD软件对采样器喷嘴口处的空气场进行流场仿真。结果表明:减少采样器冲击板的冲击长度S可以缩小喷嘴处流场的负压区域,进而提高采样器捕集效率。     

External quantum efficiency response of thin silicon solar cell based on plasmonic scattering of indium and silver nanoparticles

This study characterized the plasmonic scattering effects of indium nanoparticles (In NPs) on the front surface and silver nanoparticles (Ag NPs) on the rear surface of a thin silicon solar cell according to external quantum efficiency (EQE) and photovoltaic current–voltage. The EQE response indicates that, at wavelengths of 300 to 800 nm, the ratio of the number of photo-carriers collected to the number of incident photons shining on a thin Si solar cell was enhanced by the In NPs, and at wavelengths of 1,000 to 1,200 nm, by the Ag NPs. These results demonstrate the effectiveness of combining the broadband plasmonic scattering of two metals in enhancing the overall photovoltaic performance of a thin silicon solar cell. Short-circuit current was increased by 31.88% (from 2.98 to 3.93 mA) and conversion efficiency was increased by 32.72% (from 9.81% to 13.02%), compared to bare thin Si solar cells.     

Manufacture of magnetic circuits of axial welding equipment

Advanced technologies of producing magnetic circuits for axial welding transformers are discussed. The technologies proposed by the authors are characterized by the efficient utilization (almost without waste) of electrical engineering material, simple procedure and universal nature, high degree of automation and continuous technological process stages.     

Metronidazole-loaded nanostructured lipid carriers to improve skin deposition and retention in the treatment of rosacea

The objective of the present investigation was to improve the skin deposition and retention of metronidazole (MTZ) in rosacea therapy by incorporating it into nanostructured lipid carriers (NLCs). The main challenge in this endeavor was the partial hydrophilicity of MTZ, which mandated careful selection of excipients, including solid and liquid lipids, surfactants, and their ratios in combination. NLCs were produced by the phase inversion temperature method and finally converted into a gel for topical application. The prepared nanoparticles were evaluated for their particle size, zeta potential, entrapment efficiency, solid-state characteristics, surface morphology, in vitro drug release, and permeation through excised skin. The gel was additionally characterized for its pH, drug content, viscosity, and spreadability. The prepared nanoparticles were spherical in shape and of size less than 300?nm. Incorporation of judiciously chosen excipients made possible a relatively high entrapment efficiency of almost 40%. The drug release was found to be biphasic, with an initial burst release followed by sustained release up to 8?hours. In comparison to the plain drug gel, which had a tissue deposition of 11.23%, the NLC gel showed a much superior and desirable deposition of 26.41%. The lipophilic nature of the carrier, its size, and property of occlusion enabled greater amounts of drug to enter and be retained in the skin, simultaneously minimizing permeation through the skin, i.e. systemic exposure. The results of the study suggest that NLCs of anti-rosacea drugs have the potential to be used in the therapy of rosacea.     

艾萨炉仓式配料的动态优化管理方法研究

对艾萨炉炼铜生产过程中与精矿配料有关的问题进行分析,指出运料效率和运料质量是衡量配料质量最关键的两个指标,在艾萨炉配料生产实践中提出改进两指标措施经实施取得了较好的效果。     

Cost and revenue efficiency in DEA-R models

One of the most important information given by DEA models is the cost and revenue efficiency of decision making units (DMUs). Cost efficiency is defined as the ratio of minimum costs to current costs, while revenue efficiency is defined as the ratio of maximum revenue to current revenue of the DMU. This paper aims to create models for the estimation of cost and revenue efficiency, with particular attention being paid to ratio DEA (DEA-R) models. This group of models eliminates some of the disadvantages associated with standard DEA models. The main contribution is the formulation of linear models for cost and revenue efficiency based on DEA-R models. The results given by the new models, as well as by the standard models are compared to a real data set – the evaluation of 21 medical centers in Taiwan.     

First and second law investigations of a new solar‐assisted thermodynamic cycle for triple effect refrigeration

This investigation is persuaded for the first and second law analyses of a new solar‐driven triple‐effect refrigeration cycle using Duratherm 600 oil (Duratherm Extended Life Fluid, NY, USA) as the heat transfer fluid is performed. The proposed cycle is an integration of ejector, absorption, and cascaded refrigeration cycles that could produce refrigeration output of different magnitude at different temperature simultaneously. Both exergy destruction and losses in each component and hence in the overall system are determined to identify the causes and locations of the thermodynamic imperfection. The effects of some influenced parameters such as hot oil outlet temperature, refrigerant turbine inlet pressure, and the evaporator temperature of ejector and cascaded refrigeration cycle have been observed on the first and second law performances. It is found that maximum irreversibility occurs in central receiver as 52.5% and the second largest irreversibility of 25% occurs in heliostat field. The second law efficiency of the solar driven triple effect refrigeration cycle is 2%, which is much lower than its first law efficiency of 11.5%. Analysis clearly shows that performance evaluation based on the first law analysis is inadequate and hence, more meaningful evaluation must be included in the second law analysis. Copyright © 2013 John Wiley & Sons, Ltd.