从催化裂化柴油中分离高纯度2,6-二甲基萘

以大庆石油化工总厂炼油厂催化柴油为原料 ,通过精馏分离得到二甲基萘 (DMN)窄馏分 (2 5 8～ 2 70℃ ) ,经糠醛溶剂抽提 ,减压蒸馏后 ,在 -10～ -2 5℃冷冻 2～ 5h ,离心分离制得纯度约 80 %的粗 2 ,6 DMN ,再经无水乙醇在 -10～ -2 5℃重结晶 ,得到纯度大于等于 98%的 2 ,6 DMN。     

空间桁架结构拓扑优化设计的线性规划方法

本文以杆件内力为设计变量,构造了多工况作用下空间桁架结构拓扑优化的线性规划模型,考虑了应力和位移约束,能够避免奇异最优拓扑和不稳定结构的产生。     

一机多控视频点播系统

介绍一种自行设计、开发的一机多控视频点播系统，讲述了系统组成及设计方案，它具有服务功能多，操作方便、性能价格比高等特点。     

Synthesis and Spectral Properties of Mixed-Ligand Complexes of Lanthanide Perchlorate with Bis-(phenylsulfinyl)ethane and Organic Lewis Bases

ＳｙｎｔｈｅｓｉｓａｎｄＳｐｅｃｔｒａｌＰｒｏｐｅｒｔｉｅｓｏｆＭｉｘｅｄＬｉｇａｎｄＣｏｍｐｌｅｘｅｓｏｆＬａｎｔｈａｎｉｄｅＰｅｒｃｈｌｏｒａｔｅｗｉｔｈＢｉｓ（ｐｈｅｎｙｌｓｕｌｆｉｎｙｌ）ｅｔｈａｎｅａｎｄＯｒｇａｎｉｃＬｅｗｉｓＢａｓｅ...     

高含硫钻井液缓蚀剂的合成及性能研究

本文合成了抑制H₂S腐蚀的咪唑啉类缓蚀剂,并研究了它们的性能。正交试验表明,最佳合成条件是:反应温度:190～200℃;酸:胺(mol比)=1:1.05;反应时间以3～5小时为宜。根据以上条件合成的缓蚀剂,在含有3200mg/lH₂S的泥浆中,用量为0.2%时,抑制效果能达到80～90%,与碱式碳酸锌复配使用时,能提高缓蚀效率和降低碱式碳酸锌的用量,并发现缓蚀剂与CaO之间具有明显的协同效应。泥浆流变性能试验表明,缓蚀剂能提高泥浆的动切力和动塑比,对失水量影响不大。此外,利用X-射线衍射试验证明:(1)低碳钢在含H₂S的泥浆中,腐蚀产物的主要组成为Fe₉S₆;(2)H₂S会破坏FCLS的稳定性,分解出Fe²⁺,与H₂S反应生成面心立方的Fe₂S₄。     

石家庄市CATV系统网络技术指标分配初探

在ＣＡＴＶ系统网络工程设计中，技术指标的分配产关键问题。本文介绍了石家庄市在系统设计时采用的符合实际的设计程序，并对系统前端，传输及用户网各部分技术指标的确定，计算与分配方法，指标的核算等作了较详细地阐述，以供同行参考。     

一种提高地震速度解释精度的新方法

本以利用速度谱所伴生的叠加能量，采用二次曲线插值方法，寻找最大的叠加能量有所对应时间，然后利用叠加速度进行倾角校正，相位校正和最大炮检距校正，获取比较精确的层速度参数。     

A Petri net based approach to modeling and scheduling for an FMSand a case study

In this paper, a timed-place Petri net (TPPN) model for flexible manufacturing systems (FMSs) is constructed, which contains two major submodels: the stationary transportation model; and the variable process flow model. For multiple automated guided vehicle (AGV) systems, the authors embed a simple rule and introduce a push-AGV strategy in a TPPN model to solve the collision and traffic jam problems of such vehicles. Since a firing sequence of the TPPN from the initial marking to the final marking can be seen as a schedule of the modeled FMS, by using an A^* based search algorithm, namely, the limited-expansion A algorithm, an effective schedule of the part processing can be obtained. To show the promising potential of the proposed work, a prototype FMS is used as a target system for implementation. The experiment results assert that the job-shop scheduling problem can always be satisfactorily solved     

Coincident indices of exons and introns

In this paper, the coincident index, proposed by W. F. Friedman in cryptology, is made use of in DNA sequence analysis and exon prediction. The coincident index of exons exceeds that of introns by many times, and is mainly affected by window length, which is correlated negatively with the coincident index. An optimal exon prediction scheme was obtained by experimental analysis with an orthogonal table. Besides exons, many other special sites such as tandem repeats can be identified by using the coincident index approach. The application of this approach to the ARV-2 (AIDS associated retrovirus 2) genome found three new possible coding regions and some unusual base composition regions which are probably related to definite biological functions.     

加氢裂化反应器新型冷氢箱的研究与工程设计

报道了加氢加化反应器新型旋流式冷氢箱的研究设计及实用效果，催化剂床层径向温差不大于5℃。