ArⅡ的某些能级平均寿命的测量

用１１０ｋｅＶ的Ａｒ＾＋离子与８．５μｇ／ｃｍ＾２的碳箔相互作用，研究ＡｒⅠ、ＡｒⅡ的激发光谱，并测量了６条ＡｒⅡ的某些能级的平均寿命，其结果和别的实验及理论计算进行了比较。为了延长碳箔的使用寿命，我们改进了制箔工艺，并调节合适的电流强度，使箔的使用寿命长到３０分钟以上。     

小波级数的Bouligand维数(英)

本文讨论小波级数的上、下Buoligangd维数，在小波级数满足一定的条件下，给出了与Weierstrass函数相应的结果．     

Transthyretin (prealbumin) gene in human primary hepatic cancer.

From a subtracting cDNA library constructed from normal liver versus human primary hepatic cancer (PHC) a cDNA clone pG8 was isolated. Using it as a probe, RNA extracted from one human liver and 9 PHC samples were analyzed by Northern hybridization. As expected, its mRNA was highly expressed in liver; however, the expression was strikingly suppressed in PHC. Only weak signal was observed in 2 out of 9 PHC, while no signal was detectable in the other 7 samples. Utilizing pG8 as a probe, DNA from the same PHC specimens was analyzed after MspI digestion and Southern hybridization. Deletion of DNA fragment was observed in 4 out of 9 samples. In further study of cancer and non-cancerous liver from other 7 PHC patients, similar deletion of DNA fragments in cancer was observed in 4 out of 7 samples. After sequencing of the clone of 572 bp, it was unexpectedly found that pG8 was completely homologous to the coding sequence of transthyretin, TTR gene, as TTR (or prealbumin) gene has been known to be linked to a hereditary disorder, familial amyloidosis (FAP), and related to thyroxine transport and binding to retinol-RBP (the retinol binding protein) complex. This is the first report of a study on TTR in human primary hepatic cancer. Since TTR gene was strikingly suppressed in mRNA expression and possibly defective in its gene structure, it was strongly implicated that TTR might be an important gene marker or a candidate of anti-oncogene for human PHC. The biological activity of TTR gene is under study.     

Etched facet and semiconductor/air DBR facet of a AlGaInP laser diode prepared by focused ion beam milling

The study of focused ion beam (FIB) milling for making etched facet and semiconductor/air distributed Bragg reflector (DBR) facets of AlGaInP-based red laser diodes (LD) is presented in this letter. For the Ga ion beam current of 100 pA at fixed accelerated voltage 30 kV, FIB milling rate of GaAs was found to be 0.46 μm³/nC. As a trade-off between high reflectivity and enough technical tolerance, the combination of third Bragg orders of semiconductor wall and air gap was chosen. The deeply etched mirror and distributed Bragg reflector facet consisting of pairs of semiconductor wall/air gap on laser diodes (LD) cavity facets with vertical sidewall on AlGaInP LDs were fabricated by focused Ga ion beam milling. Comparison of the AlGaInP LD with the mirrors between cleaved and FIB made facet was given and discussed.     

激光增益系数ζ(ν)和佛克脱函数的近似积分计算—兼论δ函数在近似计算中的应用

本文分析了激光增益系数ζ(υ)和佛克脱积分函数I(υ,υ_0).指出两函数的积分困难均来源于洛伦兹分布函数和多普勒分布函数的褶积.文中进一步分析了洛伦兹函数φ_N和多普勒函数φ_D,并引出函数的峰宽比α,指出当峰宽比α_N>>α_D时,可以把积分号内的φ_N当作δ函数来处理.反之也然.这样就很容易得到ζ(υ)和I(υ,υ_0)的近似积分.     

金融资产收益分布的混合高斯分析

本文研究了金融资产收益的混合高斯分布模型 ,给出了混合高斯分布的 Kolmogorov-Smirnov检验的方法 ,分析了金融资产收益的非高斯性及市场价格运动的有效性 .此外 ,用成分数目 K*、拟合误差 DK*n和主成分系数 p*k 描述金融资产收益的性质 ,对外汇银行同业拆借市场和中国股票市场实证分析     

亚纯函数的Valiron亏函数

对于开平面内有穷级的超越亚纯函数f(z),本文主要讨论其Valiron亏函数问题,得到f(z)的Valiron亏函数的F_δ-集合必为μ-集合的结论,去掉了陈怀惠等对f(z)的极点的要求。最后指出对于无穷级的情形,也有相应的结论。     

Effect of acid strength distribution on conversion of FCC gasoline over a ZSM-5 zeolite catalyst

Summary Acid strength distribution and the distribution of aromatics formed in the FCC gasoline conversion reaction on a ZSM-5 zeolite with different Na contents have been studied. With increasing Na content in the ZSM-5 zeolite, the acid sites determined by NH₃-TPD technique, especially the strong acid sites, clearly decrease. When used as catalyst for the aromatization reaction, the transformation of olefins in the FCC gasoline into aromatics is governed directly by the strong acid sites on the ZSM-5 catalyst. Only under the conditions that a ZSM-5 catalyst possesses suitable strong acid sites is reaction temperature favorable for the aromatics formed.     

Synthesis and Characteristics of Hole-transporting Materials Based on Biphenyl Diamine Derivatives with Carbazole Groups

IntroductionThe development of organic light-emitting diodes(OLEDs)has been the subject of intensive academicand industrial research that is directed toward the fabri-cation of large-area,monocolor and full color flat-paneldisplays[1].Ever since Tanget al…