熔盐籽晶法生长三硼酸锂单晶

一、引言 三硼酸锂晶体(LiB_3O_5,简称LBO)属正交晶系,空间群为P2_1cn,晶胞参数a=5、141(6)(?),b=7.378(4)(?),c=8.446(3)(?),z=4,密度为2.48g/cm~3,Moh′S硬度约为6。它是我所继发现β-BaB_2O_4晶体(BBO)之后,又首先发现的一种新型非线性光学     

存储区域网中光纤通道和iSCSI协议的性能分析

在存储环境中,SCSI协议是被广泛采用的块存储管理协议。不同的传输机制,如,并行SCSI、光纤通道和iSCSI(internetSCSI)都可以被用于传输SCSI协议数据。对于并行SCSI来说,传输距离短、连接的设备数目少是它的主要缺点。FC和iSCSI是下一代SCSI传输机制的主要竞争对手。通过对FC和iSCSI两个协议之间不同方面的分析,评价FC和iSCSI是否满足吉比特速率、可扩展互连设备和满足存储环境和存储协议的需要。     

渣油及其加氢脱硫（VRDS）渣油的超临界精密分离的研究

采用超临界流体萃取技术（ＳＣＦＥ）,分别将ＶＲＤＳ过程的原料和产物中的减压渣油（＞４９０℃）分离为若干窄馏分,测定了渣油及其窄馏分的组成和性质。考察了孤岛减压渣油的组成和性质在ＶＲＤＳ过程中的变化。结果表明,孤岛减压渣油及其窄馏分的各项性质在ＶＲＤＳ过程中有了很大程度的改善,用改进的Ｂ—Ｌ法和密度法分别对它们的结构参数进行计算。从这些结构参数可以看出,在ＶＲＤＳ过程中,伴随着脱硫、脱氮和脱金属等反应,还发生芳环的加氢饱和、裂化反应和断侧链反应,从而使孤岛减压渣油的结构族组成发生较大的变化。ＶＲＤＳ作为渣油改质技术在重油改质加工中可以发挥重要作用     

常压渣油掺炼催化裂化油浆提高蒸馏拔出率的研究

考察了掺兑催化裂化油浆对常压渣油蒸馏的影响。研究结果表明,在常压渣油中掺兑一定比例的催化裂化油浆可以提高减压蒸馏拔出率,掺兑 ５％ 催化裂化油浆蒸馏,可以多获得 ３％ ～４％ 的馏分油,并使减压渣油的延度有一定程度的改善。工业试验结果重复了实验室研究结果。     

液压缸微小内泄漏精密检测方法及装置研究

为解决液压缸标准中微小内泄漏量的精确测量难题,提出了一种液压缸微小内泄漏精密检测方法.采用精密双作用液压缸和磁致伸缩式位移传感器组合成计量液压缸作为测试元件,设计了包含检测通道与充液补偿通道在内的新试验回路、试验流程和检测技术,并开发了液压缸微小内泄漏精密检测仪.实测结果表明,检测仪可在标准要求的测试环境下,实现对液压...     

冠心病治疗的新术式:打孔十搭桥──国内首例临床应用的报道

我们为一位47岁患者成功的施行了国内首例TMLR＋CABG手术。病人为严重广泛三支病变伴左心衰，LVEF27％，激光在左室壁打孔46个，搭桥4根，病人术后恢复顺利，症状消失、心功能明显改善，术后二周痊愈出院。     

莱钢1^#连铸机试车达产中的问题分析及处理

莱钢第一台连铸机创造了１３天达产的全国最快速度。本文就连铸机试车达产中遇到的问题及解决办法进行了分析总结，对于新建连铸机尽快达产具有一定的意义。     

基于嵌入式RTOS的分布式监控系统的设计

介绍在基于51系列微控制器的分布式监控系统中，为满足系统的实时性要求，提高系统的稳定性和可靠性，将嵌入式实时操作系统μC／OS—Ⅱ用于微控制器软件设计，将系统各个功能模块划分成不同优先级的任务，采用多任务占先式运行机制代替传统的单任务顺序运行机制，满足了系统的实时性要求，同时使系统的可靠性和可维护性都得到了很大的提高。     

大亚湾核电站旧导向筒处置方案可行性研究

描述广东大亚湾核电站旧导向筒处置方案的可行性研究，内容包括：处置方案的比较与选择，混凝土包装箱的结构设计和屏蔽设计，旧导向筒装箱操作的的工艺设计，包装箱吊装及运输方案的选择，整个处理过程中涉及到的辐射安全和工业安全的分析评价，以及整个工程的经费概算，结果表明，该旧导向筒处置方案技术上可行，经济上合理，采用此方案，对广东大亚湾核电站是导向筒进行最终处置，既可工省大量经费，也可为我国对核电站产生的不可     

A Very Low Bit Rate Video Coding Combined with Fast Adaptive Block Size Motion Estimation and Nonuniform Scalar Quantization Multiwavelet Transform

We describe a very low bit rate video coding framework in which motion correlation between successive video frames is exploited in the multiwavelet transform domain. Some complicated techniques, such as spatial prediction in intra coding, adaptive block size motion estimation, more than one previous frames for prediction in inter frames, and content adaptive binary arithmetic coding (CABAC) are used in H.26L standard. The testing results show that H.26L can greatly outperform MPEG-4 ASP in both PSNR and visual quality. However, the encoding of H.26L costs too much time for it is complex to use fast motion search in adaptive block size motion estimation, and CABAC needs much time to generate the code list for entropy coding. Whereas, only four types of symbol are generated after zero tree wavelet coding so that the entropy coding can cost less time than CABAC. Moreover, if we select 8× 8 sized block as a basic mode, which can be united into the large size mode if neighbored 8× 8 sized blocks have same reference frame and motion vector, then the fast motion estimation can be feasible. Accordingly, a fast motion search algorithm, multiwavelet transform, and a novel adaptive quantization schemer are applied to the proposed coding frame. Experimental results reveal 0.2–0.5 dB increase in coded PSNR at low bit rates over the state-of-the-art H.26L recommendation, and similar improvements over MPEG-4 at high bit rates, with a considerable improvement in subjective reconstruction quality, while simultaneously supporting a scalable representation.Jiazhong Chen was born in 1970. He received the M.S. degree in computation mathematics in 1999 and Ph.D. degree in computer system architecture in 2003 from HUST. He is now a lecturer at School of Computer science and technology of HUST. His main research interests include signal processing and wavelet analysis, image and video coding.Jingli Zhou was born in 1946. She received the B.E. degree in 1969. She is a Professor and doctor advisor at university of science and technology. She had been a visiting scholar in USA from 1995 to 1996 and has been honor of the State Department Special Allowance since 1999. Her main field of research: computer network and multimedia signal processing.Shengsheng Yu was born in 1944. Received the B.E. degree in 1967. He is a Professor and doctor advisor at university of science and technology. He had been a visiting scholar in west Germany from 1982 to 1983. His main field of research: computer network and storage, discrete signal processing and communication.Jun Xu was born in 1981. He received the B.S. degree from HUST, Wuhan, P. R. China, in 2003. He is now pursuing his M.S. degree in the School of Computer Science and Technology of HUST. His research interests are wavelet analysis, image compression and video processing and communications.