Dearomatization of Diesel by Solvent Extraction: Influence of the Solvent Ratio and Temperature on Diesel Raffinate Properties

To comply with the stringent environmental regulations concerning the quality of fuels the production of ultra low sulfur fuels is obligatory. Consequently, the removal of aromatics from fuels has turned to be a serious issue. This is due to the fact that the presence of aromatics in fuel deters the ultra-low sulfur fuel production. Therefore the researcher’s interest has involved the dearomatization of fuels. As a result of the dearomatization, the quality of fuels improves tremendously. Here, solvent extraction was performed to dearomatize a feedstock sample with 20.1% aromatic and 166 ppm sulfur using acetonitrile. The extraction was performed at low temperature and ambient atmospheric pressure. The aromatic contents were determined via HPLC, while the ASTM methods were employed in other parameters determination. The results showed 72% minimum yield, 8.6% aromatic content, 58–64 cetane index, 73.2 ppm sulfur content, 5.4 viscosity, RI 1.4535, aniline point 82.15, specific gravity 0.824–0.812 with API 40.32–42.88 and flash point 70–78°C. The boiling range of the produced diesel fraction raffinate (172–373°C) that corresponds to C₈–C₂₄ cuts render it a potential candidate for other petrochemical applications.     

KDP晶体高效二倍频理论计算

根据三波耦合方程研究了基波功率密度晶体长度，相位匹配类型，相位失配角，离散角等因素对ＫＤＰ晶体倍频转换效率的影响。给出了不同长度ＫＤＰ晶体Ⅱ类相位匹配的理论计算曲线，由此选择最佳条件进行实验，获得了８０％的倍频转换效率。     

Generation of Scattering Functions for Mobile Communication Channel: A Computer Simulation Approach

In this paper, an algorithm of generation of thescattering function by computer simulation for the WSSUSurban mobile communication channel is studied. Thescattering function, which contains much valuable information of the channel, is calculatedthrough three approaches. The empirical measuredparameter database and recommended standard methods areused to generate the scattering function as the firstand second approaches. An in-service measurement ofthe GSM network is performed in Singapore, in thefrequency range 935-960 MHz using the Rohde and SchwarzChannel Sounder. The data collected are used for the calculation, as the third approach. Thefour main characteristics of the channel, the Dopplerspread B_d, the multipath spreadT_m, the coherence time t, and thecoherence bandwidth f, are observed. The computer-calculated scattering function isshown to be an accurate and effective tool forsimulation of WSSUS channels. As a result, a softwarepackage is developed and utilized in the X-Windowenvironment for the simulation of the urban mobilecommunication channel. It can meet most of therequirements of both the system designers and theservice providers.     

静脉内弱激光照射血液治疗帕金森氏病

采用静脉内弱激光照射血液疗法（ILIB）治疗32例帕金森氏病患者，总有效率达87．6％。作者推测，ILIB可能通过改善脑微循环，纠正脑内多巴胺代谢紊乱从而防治帕金森氏病。     

Algorithm for mapping between information bits and channel symbolsin MTCM codes

An algorithm for mapping between information bits and channel symbols in multiple trellis-coded modulation (MTCM) codes with M-PSK signal sets is proposed. The core of the algorithm assigns information bits with a Hamming distance in proportion to the sum of the Euclidean distance to each M-PSK symbol. The analytical results show that the additional gains from applying the algorithm can be achieved with little or no loss     

导电衬垫材料的研究与发展

导电衬垫材料是电子设备中应用最为广泛的一类屏蔽材料，在抑制电子设备缝隙电磁泄漏方面发挥了重要作用。文章结合作者的科研工作，对于衬垫材料的抑制机理、材料类型、屏蔽特性、屏效计算、应用技术、测试方法等关键技术进行了综述，并提出了将来研究发展的方向。     

随机分布的多个非球形群聚散射体的极化散射及其数值模拟

本文利用T矩阵法,通过严格求解N个粒子的多次散射方程,发展了随机分布的多个非球形群聚散射体的集合性相干散射的计算机数值模拟方法。数值地给出了在空间随机分布的群聚散射体的极化散射与粒子的形状、大小、空间分布和取向等参量之间定量的函数关系。并将随机分布的群聚散射体的后向散射与单个粒子和单个群聚体独立散射的数值结果进行了比较,表明多个粒子的群聚分布对散射特性产生显著的影响。     

水热合成PZT纳米晶粉末烧结性及机理的研究

研究水热合成ＰＺＴ压电体纳米晶粉末的烧结性能及其机理。采用ＤＴＡ－ＴＧＡ对这种纳米晶粉末进行了热分析，结果表明，这种结晶粉末的ＰｂＯ挥发温度为９２４．７１°Ｃ，而颗粒之间的反应温度为８１１．２６°Ｃ。与此相反，固相合成ＰＺＴ粉末颗粒之间的反应温度为１２４３．４７°Ｃ，ＰｂＯ的挥发温度为１２１３．２９°Ｃ。水热合成纳米晶结晶粉末的烧结温度比固相法合成低１００°Ｃ左右     

一种先进的短波实时选频和跳频通信控制器的设计和实现

本文首先论述了短波实时选频和跳频通信的工作机理；然后讨论了控制器的两个主要功能模块，并对其跳频通信技术和控制器硬件结构，软件实现方法作了较详尽的介绍；最后给出了实时选频和跳频通信系统的实际线路实验情况。     

Development of the Base Station Controller and Manager in the CDMA Mobile System

The base station (BS) in the CDMA Mobile System (CMS) connects calls through the radio interface and is designed to provide mobile subscribers with high quality service in spite of mobile subscribers’ motions. The BS consists of multiple base station transceiver subsystems (BTSs), a base station controller (BSC) and a base station manager (BSM). This paper is concerned with the BSC and the BSM. The BSC is located between the BTSs and the mobile switching center (MSC) connected with the public network, and is responsible for controlling mobile calls from and to mobile subscribers via the BTSs. The BSM provides operator-interfaces per the BS and takes responsibility of operation and maintenance (OAM) of the BS. Design of the BSC is based on two module types: functional module and unit module. The functional module is used to support new services easily and the unit module to increase the system capacity economically. Both modular types are easily achieved by inserting the corresponding modules to the system. Particularly, in order to efficiently support the soft handover which is one of CDMA superior advantages, the BSC adopts a large high-speed packet switch connecting up to 512 BTSs, and thus mobile subscribers can be provided with soft handover in high probability. The BSM is based on a commercial workstation to support OAM functions efficiently and guarantee high reliability of the functions. The BSM uses graphical user interface (GUI) for efficient OAM functions of the BS.