Skeletal Isomerization and Inter—molecular Hydrogen Transfer Reactions in Catalytic Cracking

Bimolecular hydrogen transfer and skeletal isomerization the important secondary reac-tions among catalytic cracking reactions,which affect product yield distribution and product quality,Catalyst properties and operating parameters have great impact on bimolecular hydrogen transfer and skeletal isomerization reactions .Bimolecular hydrogen transfer activity and skeletal isomrization activity of USY-containing catalysts are higher thn that of ZSM-5-containing catalyst.Coke deposition on the active sites of catalyst may suppress bimolecular hydrogen transfer activity and skeletal isomer-ization activity of catlys in different degrees.Short raction time causes a decrease of hydrogen trans-fer reaction,but and increase of skeletal isomerization reaction compared to cracking reaction in catalytic cracking process.     

水溶性油墨用富马酸改性松香树脂的研制

介绍了一种水溶性富马酸改性松香树脂的制备方法 ,选取了较佳的工艺条件 ,本产品经国内几家油墨厂使用 ,结果表明适合水溶性油墨的应用要求     

A comparison between different PMD compensation techniques

We quantify the benefits of using different techniques for compensation of polarization mode dispersion (PMD) in fiber-optic communication systems by means of numerical simulations. This is done both with respect to PMD-induced pulse broadening and in terms of system outage probability for different data formats [nonreturn-to-zero (NRZ) and return-to-zero (RZ)]. Attention is focused on simple and relevant single- and double-stage post-transmission compensators with a few degrees of freedom (DOF). It is generally believed that a PMD compensator with a polarization controller and a variable delay line can only compensate the PMD to the first order. We show, from analytical results, the counterintuitive fact that this scheme can also partially compensate for higher order PMD. We also investigate the benefit of using a polarizer as compensation element where the optical average power can be used as a feedback signal     

利用框架理论对信号进行重建

在Hilbert空间中讨论了框架的一些重要的性质,定义了一个框架算子,并讨论了该算子的性质。根据实际问题构造了一框架,使信号在此框架下的投影正好为非均匀采样值。给出了一种框架界的估计方法和重建原信号的迭代算法,最后,用仿真验证了此算法的有效性。     

全站仪在直升机悬停测试中的应用

介绍了如何将改造后的全站仪应用于直升机悬停性能测试的方法。经真实飞行试验检验，该方法理论严密，方案合理，改装简单，操作方便，成本低廉。较之原始的摄影测量法有无法替代的优点。     

一种有效的优化的多载波通信系统的功率分配算法

本文提出一种关于DMT系统传输纯数据流业务的最佳的功率分配算法，该算法使用了一种有效的表格查手工艺工和拉格朗日乘法器对分搜索办法，能够较快的收敛到最佳的功率点。同时，易于用硬件和软件实现。     

建立速度模型的层析成像方法研究

针对目前叠前深度偏移速度模型建立中，全局反演的层析成像方法存在稳定性和走时拾取困难，以及局部反演的偏移速度分析大多存在假设条件过于苛刻等问题，通过分析，提出了利用地震同相辅的多种信息进行层析反演，并在反演中加入富有地质含义的倾角信息以增加反演过程的稳定性和收敛速度，利用类似于叠加速度谱的斜率速度谱来拾取地震同相轴的斜率，抛开了层位反演要求拾取同一同相轴这一实际应用难度很大的条件，使拾取方便，算法稳定。通过理论试算，证明了本方法的有效性。     

A robust adaptive pole‐placement controller without strictly positive real condition

This paper considers the adaptive pole‐placement control problem for system (1) with unmodelled dynamics η_n dominated by a small constant ε multiplied by a quantity independent of ε but tending to infinity as the past input, output, and noise grow. Using bounded external excitation and randomly varying truncation techniques, we give a design method of adaptive pole‐placement controller. It is shown that the closed‐loop system is globally stable, the estimation error for the parameter contained in the modelled part is of order ε, and the closed‐loop system under the adaptive pole‐placement control law is suboptimal in the sense of $$\mathop{\lim\sup}\limits_{{n\to\infty }}{1\over n}\mathop{\sum}\limits_{i=0}^n{\left({A^{*}(z)y_{n}‐L(z)C(z)w_{n}‐B(z)R(z)y_{n}^{*}}\right)^{2}{\leq}O({\varepsilon}^{2})+\gamma^{2}\mathop{\sum}\limits_{j=1}^q{b_{j}^{2}}}$$\nopagenumbers\end while the SPR condition used usually in other papers is replaced by a stability condition. Copyright © 2001 John Wiley & Sons, Ltd.     

HP700圆锥破碎机动锥的有限元分析

对HP700圆锥破碎机的主要部件动锥建立了有限元分析模型，用ANSYS软件对动锥进行了有限元强度和刚度分析，结果输出了动锥分布及变形图，对圆锥破碎机的结够设计提供了依据。