迷宫螺旋泵和密封工作特性研究

介绍了一种实测迷宫螺旋泵和密封工作特性的实验方法,通过该方法可以测得迷宫螺旋泵的泵送特性曲线、迷宫螺旋端面组合密封的最大密封压力以及端面开启的开始转速,具有一定的实用价值。     

H型丝光沸石催化剂催化甲苯与叔丁醇的烷基化反应

针对合成对叔丁基甲苯传统工艺中存在的缺点,采用环境友好、可重复利用的H型丝光沸石催化剂(以下简称催化剂)进行了甲苯与叔丁醇的烷基化反应,并用X射线衍射和氨程序升温脱附等方法对不同焙烧温度下得到的催化剂的物相结构和酸性质进行了表征,研究了各种反应条件对催化剂的催化性能的影响。实验结果发现,在适宜的操作条件下,即催化剂的焙烧温度823K、反应温度180℃、反应时间3h、初始压力1.0MPa、原料与催化剂的质量比为8、叔丁醇与甲苯的摩尔比为4、溶剂环己烷与甲苯的摩尔比为5时,甲苯转化率达42.73%,叔丁基甲苯的选择性为96.30%,对叔丁基甲苯的选择性为80.37%。     

2.4GHz动态CMOS分频器的设计

对现阶段的主流高速CMOS分频器进行分析和比较,在此基础上设计一种采用TSPC(truesingle phase clock)和E-TSPC(extended TSPC)技术的前置双模分频器电路.该分频器大大提高了工作频率,采用0.6μm CMOS工艺参数进行仿真的结果表明,在5V电源电压下,最高频率达到3GHz,功耗仅为8mW.     

Laterally coupled buried heterostructure high-Q ring resonators

All-buried InP-InGaAsP ring resonators laterally coupled to bus waveguides are demonstrated. The buried configurations offer a lower built-in refractive index step along the resonator periphery, which affords enhanced optical coupling coefficients between the waveguides and reduced scattering losses caused by the resonator sidewall imperfections. Very low optical intensity attenuations of 0.4 cm/sup -1/ and coupling-limited quality factors of greater than 10/sup 5/ are observed from 200-/spl mu/m-radii ring resonators. The measured spectral linewidth is as narrow as 0.0145 nm.     

Spectral shape tunable band-rejection filter using a long-period fiber grating with divided coil heaters

We have developed a new type of tunable band rejection filter, which provides high spectral-shaping flexibility in a wide tuning range. The filter consists of a long-period fiber grating (LPFG) with divided coil heaters. Each of the divided coil heaters is controlled individually to adjust a temperature distribution along the LPFG and to modify the spectral shape of the LPFG filter. The tunable band rejection filter is demonstrated to function properly when applied as an erbium-doped fiber amplifier gain-flattening filter.     

设计管理信息系统的提出及其面临的问题

从管理和设计的两个方面出发，通过对现代企业产品设计管理信息系统的探讨，阐明了设计管理信息系统的概念和结构；并对其实施的条件及面临的困难进行了系统的分析。     

Studies on high density polyethylene (HDPE) functionalized by ultraviolet irradiation and its application

The structure and properties of high density polyethylene (HDPE) functionalized by ultraviolet irradiation at different light intensities in air were studied by electron analysis, FTIR spectroscopy, contact angle with water, differential scanning calorimetry and mechanical properties measurement. The results show that oxygen‐containing groups such as C?O, C—O and C(?O)O were introduced onto the molecular chain of HDPE following irradiation, and the rate and efficiency of HDPE functionalization increased with enhancement of irradiation intensity. After irradiation, the melting temperature, contact angle with water and notched impact strength of HDPE decreased, the degree of crystallinity increased, and their variation amplitude increased with irradiation intensity. Compared with HDPE, the yield strength of HDPE irradiated at lower light intensity (32 W m^?2 and 45 W m^?2) increases monotonically with irradiation time, and the yield strength of HDPE irradiated at higher light intensity (78 W m^?2) increases up to 48 h and then decreased with further increase in irradiation time. The irradiated HDPE behaved as a compatibilizer in HDPE/polycarbonate (PC) blends, and the interface bonding between HDPE and PC was ameliorated. After adding 20 wt% HDPE irradiated at 78 W m^?2 irradiation intensity for 24 h to HDPE/PC blends, the tensile yield strength and notched Izod impact strength of the blend were increased from 26.3 MPa and 51 J m^?1 to 30.2 MPa and 158 J m^?1, respectively. Copyright © 2003 Society of Chemical Industry     

光纤通信在天波超视距雷达中的应用

天波超视距雷达是低空防御系统中一种有效的预警手段。通过采用光纤传输技术，利用其信息传输容量大，速度快，频带宽，抗干扰能力强，线路损耗低。易于施工等特点，实现全相参雷达的信息传输和系统控制，具有优良的保密性，稳定性、抗干扰性和抗摧毁能力。     

FCC汽油叠合生产柴油的研究——(Ⅰ)叠合催化剂的研制

采用中孔γ-Al2O3为载体，以非贵金属Ni为活性金属组分，以金属Sn为助剂组分，制备了FCC汽油叠合生产柴油的催化剂。在实验室小型连续流动式固定床装置上，以FCC汽油为原料，考察了主活性金属负载量、助催化剂、催化剂制备条件对催化剂性能的影响。研究结果表明，在活性金属Ni质量分数为8％，助催化剂Sn质量分数为1％，浸渍时间6h，焙烧温度500℃，焙烧时间4h的条件下，制备的叠合催化剂的催化性能最好。并对催化剂进行了1500h的稳定性试验和再生性能考察，结果表明该叠合催化剂具有良好的稳定性和再生性能。     

农村通信如何"突围"

农村通信作为农村地区信息化的基础，对于全面建设小康具有特殊的重要地位。介绍了我国农村通信的发展现状，分析了农村通信发展的困难压其原因，最后对农村压边远、欠发达地区通信的均衡震展提出了一些建议。