辽河催化裂化澄清油中间馏分热反应研究

采用先加入絮凝剂脱灰，再经减压蒸馏切割420～500℃馏分的方法，将辽河催化裂化澄清油预处理，考察了澄清油、加入絮凝剂脱灰后的澄清油以及脱灰后再减压蒸馏所得的中间馏分这3种原料在热转化过程中中间相的转化历程，并采用偏光显微镜观察热转化产物。结果表明，澄清油预处理效果明显，所得中间馏分具有较低的H／C原子比（nH／nC）和适宜的组成分布，是生产针状焦的理想原料。热转化产物的光学组织结构属于各向异性发达的广域-流线型结构。     

A Novel Segmentation and Feedback Model for Resolving Contention in Optical Burst Switching

A novel segmentation and feedback model (SFM) applied to resolve contention is proposed. Simulation and performance analyses show that the SFM effectively avoids contentions in optical burst switching (OBS). The long delay time of deflection routing and the immature technology of wavelength converters and optical buffers are not deployed in the SFM. The SFM does not only realize fast switching but also allows preemption by higher priority bursts.     

质子交换铌酸锂波导MMI光功分器

利用三维非旁轴近似光束传输法对退火质子交换铌酸锂渐变折射率分布波导中的自镜像效应进行分析与模拟 .在此基础上 ,利用退火质子交换技术在 X切 Y传铌酸锂衬底上进一步制作了 1× 8MMI光功分器 .测试表明器件实现了 1路分成 8路的光功分功能 .     

光纤接入网步入快速发展期

光纤接入一直是多年来人们不断追求的梦想和探索的技术方向，但由于成本、技术、需求等方面的障碍，至今还没有得到大规模推广与发展。然而，这种局面最近有了很大的改观，出现可迅速发展的势头。主要是因为一些国家政策的扶持、运营商竞争的需要、对收入的追求，以及设备本身价格的下降，光纤接入技术由于各种原因，至今尚未在全球广泛应用，但在日本、美国、瑞典和意大利等国都获得了较多的应用。在中国，光纤接入也有了良好的开端，将在大城市广泛应用，并逐渐推广到全国。     

市县HFC系统如何选择和使用光端机

对有线电视工程设计中如何选用优质设备、提高网络质量等问题进行探讨     

Organosoluble and light-colored fluorinated polyimides derived from 2,3-bis(4-amino-2-trifluoromethylphenoxy)naphthalene and aromatic dianhydrides

A novel fluorinated bis(ether amine) monomer, 2,3-bis(4-amino-2-trifluoromethylphenoxy)naphthalene, was prepared through the nucleophilic aromatic substitution reaction of 2-chloro-5-nitrobenzotrifluoride and 2,3-dihydroxynaphthalene in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. A series of new fluorine-containing polyimides having inherent viscosities of 0.54 to 1.10 dl/g were synthesized from the diamine with various commercially available aromatic dianhydrides using a standard two-stage process with thermal imidization of poly(amic acid) films. These polyimides were highly soluble in a variety of organic solvents, and most of them afforded transparent, light-colored, and tough films with good tensile strengths. These polyimides exhibited glass transition temperatures (T_gs) of 247-300 °C and showed no significant decomposition below 500 °C under either nitrogen or air atmosphere. Except for the polyimide derived from pyromellitic dianhydride, the polyimide films were almost colorless, with an ultraviolet-visible absorption cutoff wavelength below 400 nm and low b∗ values (a yellowness index) of 10.7-41.9. These polyimides had dielectric constants of 3.09 to 3.65 (1 MHz) and moisture absorptions in the range of 0.2-0.3 wt%.     

高入纤功率光纤通信系统的可靠性研究

掺铒光纤放大器(EDFA)和拉曼放大器(FRA)的使用,使得光纤通信系统中的入纤功率有了很大的提高.较高的入纤功率不仅会在光纤中引起各种非线性效应,对光脉冲的传输产生影响,也会对光纤本身的可靠性产生影响,为此介绍了高入纤功率对光纤系统的影响,分析了其产生的机理,并提出了应对措施.     

电力光通信网浅谈

介绍了电力通信中SDH光传输网在业务分布、光缆连接结构方面的特点,并结合这些特点探讨了网络合理组织、保护技术和设备选择的方案。     

The Role of Network Topologies in the Optical Core of IP-over-WDM Networks with Static Wavelength Routing

In this paper, we present a performance analysis of network topologies for the optical core of IP-over-WDM networks with static wavelength routing. The performance analysis is focused on regular degree four topologies, and, for comparison purposes, degree three topologies are also considered. It is shown that the increase of the nodal degree from three (degree three topology with smallest diameter) to four (degree four topology with smallest diameter) improves the network performance if a larger number of wavelengths per link is available. However, the influence of wavelength interchange on the nodal degree gain is small. The performance of regular degree four topologies with smallest diameter is also compared with the performance of mesh–torus topologies (which are also degree four topologies), and it is shown that the blocking probability of degree four topologies with smallest diameter is about two orders of magnitude lower than the blocking probability of mesh–torus topologies. It is also presented a performance comparison of WDM-based networks with nodal degrees ranging from two to five and it is shown that the increase of the nodal degree from two to three leads to high nodal degree gains, while de increase of the nodal degree from four to five leads to low nodal degree gains. These results show that degree three and degree four topologies are very attractive for use in the optical core of IP-over-WDM networks.     

光通信用垂直腔面发射激光器的进展

垂直腔面发射激光器(VCSEL)以其优异的性能有望成为信息时代的新光源.文章介绍了用于光通信的VCSEL的开发现状.