Formation Mechanism of Discoloration on Die-Cast AZ91D Components Surface After Chemical Conversion

A notebook (NB) computer component was manufactured from AZ91D Mg alloy by a die-casting process. After chemical conversion treatment, a discoloration was noted on the component surface. The source of this discoloration has been studied in detail by scanning electron microscopy, energy dispersive spectroscopy, and spark atomic absorption spectroscopy. The corrosion resistance was also measured by potentiodynamic polarization, hydrogen evolution and salt spray testing. The formation mechanism for the discoloration which was caused by the residue left behind by excess mold release agent sprayed during the die-casting was discussed in detail. After chemical conversion treatment, the residual-baked mold release agent was apparent on the component surface as “white ash.” Consequently, it degraded seriously both the appearance and the corrosion resistance of the manufactured component.     

Effect of solution concentration on the structures and corrosion inhibition behavior of γ-APS films fabricated on surface of low carbon steel

Effect of solution concentration on the structures and corrosion inhibition behavior of γ-APS films fabricated on surface of low carbon steel was systematically studied by EIS, RA-IR, and AFM. The experimental results indicated that the impedance of γ-APS silane treated substrates and the cross-linking degree of γ-APS films gradually increased with the increasing solution concentration. There was some noticeable transformation in molecular orientation and protective performance of γ-APS films when solution concentration was above 10vol%. High cross-linking degree and changes in molecular orientation generated γ-APS films with excellent protective performance and ordered arrangement.     

西安地区既有居住建筑节能改造初探

针对西安地区既有居住建筑能耗大的问题,本文通过论述既有居住建筑改造现状和能耗现状,并对其能耗进行分析,指出西安地区既有居住建筑节能改造的重点在于围护结构的改造和周边环境的改进。同时,提出了相关的节能改造措施,希望能为西安地区既有居住建筑节能改造提供参考。     

A reassessment of Asian pacific excellence programs in higher education: the Taiwan experience

With the growth of competition between nations in our knowledge-based world economy, excellence programs are becoming a national agenda item in developing as well as developed Asian countries. The main purpose of this paper is to compare the goals, funding policies and selection criteria of excellence programs in China, Japan, Korea and Taiwan and to analyze the academic achievement of their top ranked universities in three areas: research output, internationalization, and excellence, by using data from the Shanghai Jiao Tong, QS, and HEEACT rankings. The effectiveness of Taiwan??s ??Development Plan for World Class Universities and Research Centers of Excellence?? was assessed as a case study in the paper via a survey targeting on 138 top administrators from 11 Taiwan??s universities and 30 reviewers. The study found that more funding nations had, the more outputs and outcomes they would gain, for example China. The Taiwan case demonstrates that world-class universities and research centers are needed in Asian nations despite the concerns for inequality which they raise.     

Effect of C/Ti ratio on self-propagating high-temperature synthesis reaction of Sn-Ti-C system for fabricating Ti2SnC ternary compounds

Ti₂SnC ternary compound was successfully synthesized utilizing laser ignited self-propagating high-temperature synthesis (SHS) of Sn-Ti-C system with the different C/Ti molar ratio. When C/Ti ratio is 0.7, Ti₆Sn₅ as the main phase appears, and a small amount of TiC is also found, most of the Ti₆Sn₅ phases synthesized exhibit the polygon-shaped coarse appearance with an obviously sintered morphology, and the distinct transgranular and intergranular microcracks can be observed. When C/Ti ratio increases over the range from 0.8 to 1.0, the relative content of Ti₂SnC increase and the plate-like shape Ti₂SnC appears. Furthermore, the sintered density increases firstly and then decreases with the increasing of C/Ti ratio.     

平板电视可靠性MTBF的管控论述

越来越多平板电视厂商意识到要通过提高产品的可靠性来提高品牌美誉度和降低售后三包成本.因此,该文论述了可靠性的衡量指标MTBF和统计方法,并且研究如何在开发阶段进行MTBF鉴定,以及到量产阶段仍然进行有效监控.可以直观地指导厂商进行平板电视可靠性管控.     

浆染长车改善染色效果的实践

传统浆染长车染色由于染槽数量限制,存在染色深度不足、染色牢度较差等问题,易造成染料浪费。通过在浆染长车中加入一组烘筒,对色纱进行烘燥以去除纱线中残存的大部分水分,再继续染色,可使牛仔面料颜色深度和牢度明显提升,丰富了牛仔纱染色工艺。