仲丁醇含量对正丁烯直接水合法制仲丁醇的影响

研究了正丁烯直接水合法制仲丁醇工艺中原料水中仲丁醇含量对反应的影响.当原料水中含有少量仲丁醇时(约0.9%时),其对水合反应过程的转化率影响不大;原料水中含有少量仲丁醇时,反应过程的稳定性比较好.当水合反应的原料水中仲丁醇浓度增大时(原料水中仲丁醇浓度为2.0%左右时),反应过程的转化率明显下降.当水合反应的原料水中仲丁醇含量进一步增大时,反应过程的转化率下降明显,但呈非线性变化.     

Comparison of structural and photoluminescence properties of ZnO thin films grown by pulsed laser deposition and ultrasonic spray pyrolysis

ZnO thin films have been deposited by pulsed laser deposition (PLD) and ultrasonic spray pyrolysis (USP) method, respectively. X-ray diffraction and transmission electron microscopy characterizations indicate that ZnO film grown by PLD exhibits better crystallinity than that grown by USP. Photoluminescence spectra show that the near-band edge ultraviolet emission of film grown by PLD is narrower and shifts to higher energy, compared with that of film grown by USP. In the visible range, ZnO film grown by PLD exhibits four local level emission centered at 470 nm, 486 nm, 544 nm, and 613 nm, respectively, while the film grown by USP only presents a weak broad band emission centered at 502 nm. Hall measurement shows higher carrier density and lower hall mobility in ZnO film grown by PLD than that in film grown by USP. The higher density of intrinsic defects as well as higher crystallintiy is considered to account for the difference of photoluminescence in ZnO film grown by PLD with that in film grown by USP.     

DS-SS通信扩频序列的估计

该文给出一种在各通信参数未知的情况下估计出DS-SS通信中伪随机码的方法,并对这一算法进行了仿真及性能分析。     

不同控制策略的小功率Boost-APFC性能研究

为了使用于小功率场合的功率因数校正电路的综合性能最优化,本文研究了采用电流断续模式或临界断续模式和电流连续模式的小功率Boost-APFC的各项性能。通过仿真分析和实验比较相结合的方法,定量给出了各电路在输入电流特性、效率、EMI滤波等性能上的具体差异,并且考虑了使用SiC二极管后对电路性能的影响。     

Antibacterial Characteristics of ZnO-CeO2 Nano-Powder Prepared by Laser Vapor Condensation

Microbialpollutionandcontaminationbymicroor ganismshaveproducedvarioustroublesinindustryandothervitalfields ,suchasdegradationandinfec tion .Thenewpasteurizationandantibacterialtech niqueshavebeendemandedandstudied[1] .Inrecentyears ,therareearthmetaloxid…     

Magnetic Perovskite Superlattices Grown by Pulsed Laser Deposition

Magnetic multilayers of (SrRuO₃) _m (SrMnO₃) _n were grown artificially using the pulsed laser deposition technique on (001)-oriented SrTiO₃ substrates. The temperature and magnetic field dependent reisistivity of the superlattices consisting of ferromagnetic (FM) SrRuO₃ and antiferromagnetic (AFM) SrMnO₃ are studied as a function of the SrRuO₃ unit cells. We observed a pinned/biased moment instead of the biased field in the superlattices and we redefine the structure as AFM/FM(Pin)/FM(Free)/FM(Pin) units below a critical field.     

激光强化处理参数对轧辊表面性能的影响

通过试验，研究了激光功率、光斑直径、扫描速度、搭接量和合金粉含量等激光处理工艺参数对轧辊表面性能的影响，结果表明，轧辊表面经激光淬火处理后。性能稳定，耐磨性和抗疲劳性均有所提高，达到了生产要求．     

汽车尾气在路检测技术

随着社会经济的快速发展，我国的汽车的数量也逐年快速上升，汽车排出的尾气已经成为一个重要的污染源。因此，快速方便地检测汽车尾气，已成为一个重要的课题。本文介绍了一种用可调谐激光器的差分吸收法的探测汽车尾气方法，可以在路边检测行进中的汽车的尾气是否超标。     

堆泵浦3He-Ar-Xe激光体系小信号增益与效率实验研究

介绍了CFBR-Ⅱ堆泵浦3He-Ar-Xe体系1.73μm波长激光小信号增益和泵浦效率的实验研究.在脉冲峰热中子注量率为6.9×1014cm-2.s-1、3He、Ar、Xe气体的比例为80.219.30.5,总压强为8.3×104Pa时,采用透射率从1.7%到10%的6个谐振腔输出镜均获得了激光输出.在谐振腔输出镜透射率为7%时,得到了激光脉冲峰功率为45mW,其对应的激光泵浦效率为1%.在此基础上,利用Rigroa分析方法拟合出3He-Ar-Xe体系激光的小信号增益为0.24%/cm,饱和光强为36W/cm2.