改性 Ag/TS-1上丙烯直接气相氧化合成环氧丙烷的研究

在150℃、常压固定床石英反应器中，考察了Ag／TS-1催化剂上分别添加Cu、Pd、La，水汽处理，硅烷化处理及洗涤程度等处理方法对丙烯气相氧化性能的影响。采用UV-Vis、TEM和ICP等分析方法对催化剂进行了表征。结果表明，少量Pd的存在有利于提高催化剂的稳定性；在催化剂的制备过程中，La沉淀于载体上再担载Ag与La浸渍于载体上再担载Ag相比，环氧丙烷(PO)的选择性由90％下降至64％。水汽处理会使催化剂性能大幅度下降。对载体进行适量的硅烷化处理，有利于提高催化剂的活性和选择性。TEM测试表明，过量的SiO2担载量使担载于催化剂表面的Ag颗粒增大，从而使环氧丙烷的选择性由98％下降至90％。当SiO2担载量为2％(质量分数)时，丙烯转化率和环氧丙烷选择性分别为2．1％和98％。在制备过程中未经洗涤的催化剂比经过洗涤的催化剂的Ag和K的含量略高，表现出较佳的催化性能，其活性和选择性分别为2．43％和86．97％。     

基于主动抛弃的MPEG—2 TS流速率控制算法

在网络传输能力不足以实时传输MPEG-2码流时，接收端的图象恢复质量会因为在网络传送中不可避免的、随机的数据丢失而严重下降，为了解决这一问题，提出了一种基于主动抛弃的MPEG-2 TS流速率控制算法，即在原始码流输送到网络前，根据预测的网络传输阻塞状况，预先主动抛弃部分不太重要的数据，从而使实际输出码率与可用网络带宽匹配，以保护重要数据和改善接收端的图象恢复质量，并提高网络带宽的利用率，经实验测试证明，此算法简单、实用、有效、且接收端的图象恢复质量比任凭网络随机丢失的情况有明显改善。     

H∞Fuzzy State‐Feedback Control Plus State‐Derivative‐Feedback Control Synthesis for Photovoltaic Systems

This paper addresses the problem of designing an H_∞fuzzy state‐ feedback (SF) plus state‐derivative‐feedback (SDF) control system for photovoltaic (PV) systems based on a linear matrix inequality (LMI) approach. The TS fuzzy controller is designed on the basis of the Takagi‐Sugeno (TS) fuzzy model. The sufficient condition is found such that the system with the fuzzy controller is asymptotically stable and an H_∞performance is satisfied. First, a dc/dc buck converter is considered to regulate the power output by controlling state and state‐derivative variables of PV systems. The dynamic model of PV systems is approximated by the TS fuzzy model in the form of nonlinear systems. Then, based on a well‐known Lyapunov functional approach, the synthetic is formulated of an H_∞fuzzy SF plus SDF control law, which guarantees the L₂‐gain from an exogenous input to the regulated output to be less than or equal to some prescribed value. Finally, to show effectiveness, the simulation of the PV systems with the proposed control is assessed by the computer programme. The proposed control method shows good performance for power output and high stability for the PV system.     

一种基于TS201的高速信号相位差测量系统设计

研究了一种基于TS201的相位差测量系统设计,利用同频正弦信号的互相关函数的特性,得到相位差信息,并对影响测量结果的采样点数,量化位数,信噪比进行了分析.同时本文给出了测量系统构建的软硬件设计,及具体的仿真试验数据,理论及仿真实验结果表明本文的算法具有很高的测量精度,算法简单,物理意义明确,实时性强,特别适合高速信号的相位差信息的捕获,在工程上具有一定的实用价值.     

以分子氧为氧源催化丙烯环氧化制环氧丙烷研究进展

环氧丙烷是重要的基础化工原料。主要工业生产方法有氯醇法和Halcon法。氯醇法环境污染严重 ,急待改进 ;Halcon法产生大量联产品 ,且基本建设投资巨大。为了满足环境和经济等方面的要求 ,以分子氧为氧源的丙烯催化环氧化是最理想的生产方法 ,目前正处于研究阶段。文中对近十年来的研究进展做了综述     

Energy management in metro-transit systems: An innovative proposal toward an integrated and sustainable urban mobility system including plug-in electric vehicles

The energy consumptions growth, the upward interest for environmental sustainability and the technological evolution carry to the necessity to review the planning criteria of urban mobility systems in large cities and metropolitan areas. With this aim, new studies and projects are in progress, especially dealing with the power systems for metro-transit lines and surface electric vehicles. In this framework, the authors perform a study that, from an overview about the main energy management issues connected to the city transport, provides an innovative proposal for the design of sustainable urban mobility system: the integration of the metro-lines with surface plug-in electric vehicles. The present paper includes the energy analysis results, obtained by an application on a real case study of an home-made simulation software, describes the proposal in terms of power systems architecture and business models, pointing out the potential advantages that its implementation could give in terms of energy saving, environmental sustainability and reduced economic impact, as a result of the maximum exploitation of existing electric power plant.     

含有恒功率负荷的直流微网鲁棒非脆弱模糊控制

当具有恒功率特性的负荷与源侧换流器级联时,会降低直流微网系统的阻尼,带来稳定性问题.针对上述问题,采用TS模糊模型,对含恒功率负荷的非线性直流微网系统进行建模.为有效抵抗直流微网和控制系统参数的不确定性,设计了一种鲁棒非脆弱控制器,在计算参数不确定矩阵的基础上,推导以线性矩阵不等式表示的Lyapunov指数稳定条件.经...     

氨压缩机机组的防喘振控制及应用

离心压缩机是工业生产中的关键设备。离心压缩机喘振故障状态对压缩机的危害极大,为了保证压缩机的正常运行,必须配备控制系统来防止喘振的发生。基于三重化冗余容错技术（TMR）的压缩机控制系统TS3000有一套针对性强、速度快的防喘振技术,巴陵石化公司的氨压缩机组采用TS3000系统防喘振控制并取得了满意的效果。     

基于图论的电力系统PMU布点优化算法

基于最小支配集理论和电力系统线性量测模型,提出了可观测节点集合、WAMS可观测矩阵两个概念以及一种新的节点可观测性计算规则。以保证系统的完全可观测性和以系统图的最小支配集为搜索范围构成约束条件, 以电力系统状态完全可观测和相量测量装置（PMU）配置数目最小为目标,形成了PMU配置优化问题。并应用禁忌搜索(TS)方法求解该问题,保证了全局寻优。最后采用 IEEE 14、30、57 、118节点系统和新英格兰 39 节点系统对该方法进行了验证,仿真结果表明该方法的有效性和可行性。