中国民航票价历史演进与未来趋势

中国民航票价的历史发展可以分为三个阶段,主要特点是政府定价、成本定价,但随着民航市场化进程的加速,市场机制下的多方博弈价格将成为发展趋势,在日益激烈的竞争条件下,多种形式的票价将大量呈现,新的定价技术也将被采用

改良式解剖性大脑半球切除术治疗婴儿痉挛性偏瘫伴癫痫的远期疗效

为了克服解剖性大脑半球切除术的远期合并症，作者对传统术式进行了改良，并对３１例婴儿痉挛性偏瘫伴癫痫的病例进行了疗效的远期随访。结果表明，本术式死亡率为０％，其中２８例癫痫发作完全停止（占９０％），其余３例基本控制。行为异常得到改善、原有偏瘫无加重。神经影像学表现为健侧大脑半球明显向术腔发育；病例的脑干听觉诱发电位Ⅰ波潜伏期（ＰＬ）与对照组间差异无显著性意义（Ｐ＞０．０５）。作者认为，应用本改良法后消除了以往术式造成的巨大硬膜下术腔的病理解剖因素，并证实未发生常见的远期合并症

Effects of Nickel Content and Simulated Heat Affected Zone of 2205 Duplex Stainless Steel on Pitting Corrosion

本文研究了Ｎｉ元素及不同模拟焊后热影响区（ＨＡＺ）组织对２２０５双相不锈钢孔蚀性质之影响．结果发现：在研究成分范围内，不同Ｎｉ含量对于底材电化学极化曲线之影响不大，其Ｅｎｐ和Ｅｎｐ均在１１００～１２００ｍＶ之间．然而不同冷速之Ｇｌｅｅｂｌｅ模拟ＨＡＺ组织，其极化曲线不但阳极电流密度增加，Ｅｎｐ及Ｅｎｐ下降，钝态区域缩小，且循环扫描以后有明显迟滞现象．显示经过不同冷却时间之热履历，已破坏２２０５双相不锈钢抗孔蚀能力，而蚀孔形成后之再钝化能力也变差．电解分离分析法证实形成Ｃｒ２Ｎ之Ｎ含量超过２００×１０－６时，循环极化曲线积分之Ｑ值有显著增加之趋势，显示ＨＡＺ组织抗孔蚀性质能力主要和Ｃｒ２Ｎ析出量多寡有关，Ｃｒ２Ｎ愈多，孔蚀生长之速率也愈快．但部份ＨＡＺ组织会形成Ｃｒ２Ｎ无析出区，此种无析出区不易诱发蚀孔The effects of nickel content and Gleeble simulated heat affected zone(HAZ) of 2205 stainless steel on pitting corrosion were investigated in this paper. The results showed that nickel content, ranging from 4.5 wt% to 6.5 wt% in base metal, had only a minor effect on the electrochemical polarization curves, with all Enp's and Epp's falling in the rang of 1 1001200 mV. Comparing with the base metal, the simulated HAZ microstructure caused an increase in the anodic current density, a distinct decrease in both Enp and Epp , and a reduction in the passive range. Furthermore, hysteresis behavior was found as revealed in each cyclic polarization curve with different cooling cycle. It indicated that the pitting corrosion resistance and repassivation ability of duplex stainless steels were deteriorated by thermal cycling. Electrolytic extraction method proved that the Q values of integral cyclic polarization curves markedly increased while the nitrogen as Cr2N exceeded 20010-6. The susceptibility to pitting corrosion of HAZ was colsely related to the amount Cr2N precipitete. The higher the amount of Cr2N precipitated, the faster the rate of pitting propagation. However, in the nitride precipitate_free zones(PFZ), no pitting corrosion resistance was observed.作者联系地址：成功大学材料科学及工程学系,中国钢铁公司钢铝研究发展处Author's Address: Dept. of Materials Sci. and Engin., Cheng Kung Univ., Tainan Hsieh RongiuanPan Yeongtsuen Steel and Aluminum Research and Development Dept., China Steel Corporation, Kaohsiun

实验测定~(183)0s的Q_(EC)值

用39 MeV-α粒子轰击天然钨靶产生了~(183)Os测量了~(183)Os衰变的γ-β符合谱,确定了β~+能谱的端点能量。最终提取出~(183)Os衰变的Q_(EC)值:Q_(EC)=2.24±0.10 MeV,与系统学的估计值:2.304±0.10MeV在误差范围内相符