新型TV-VGA转换器的研制与开发

介绍了一种利用新型的Ａ／Ｄ和Ｄ／Ａ芯片,以及ＦＩＦＯ行存储器组成的ＴＶ－ＶＧＡ转换系统。该系统具有成本低,电路简单可靠等优点。     

Dynamic process intensification of binary distillation based on output multiplicity

Process intensification focuses largely on process and equipment design. Much less emphasis has been placed on operational changes to achieve cost savings and increased efficiency. This article introduces the concept of dynamic intensification, defined as changes to the dynamics, operating strategy and/or control of a process that lead to a substantially more efficient processing path. This idea is illustrated in the context of binary distillation. Output multiplicity properties are exploited to establish a new periodic operating mode based on switching between two auxiliary products, which, on a time-average basis, is more energy efficient than steady-state operation. An extensive case study is presented concerning the distillation of a propanol–acetic acid mixture, confirming the theoretical developments. In contrast to previous research (e.g., on cyclic distillation), the present concept has significant advantages as it relies on existing hardware and exploiting system nonlinearity, rather than using specialized equipment operated in a discontinuous fashion. © 2018 American Institute of Chemical Engineers AIChE J, 65: 1162–1172, 2019     

我国建筑遗产保护与利用立法研究

以建筑遗产概念的内涵演变及其价值的多重性开篇,探讨了我国建筑遗产立法现状与不足,并在此基础上,以意大利建筑遗产保护和利用理念及立法的发展历程为借鉴,结合我国目前建筑遗产保护和利用理念及实践发展现状,对我国建筑遗产保护和利用的立法提出了分类保护原则等建议。     

高压变频器36脉波移相变压器的设计

高压变频器是指输入电源电压在3—10kV的大功率变频器。由于其功率大、电压等级高,所以对其输入谐波、功率因数等要求很高。采用移相变压器实现高压变频器的多重化整流,可使高压变频器的输入谐波减小,功率因数提高。对容量为630kVA,36脉波移相变压器的电流、匝数参数进行设计,并对多重化整流电路进行谐波和仿真分析,为工程实践提供依据。     

金属类配合物与肿瘤相互作用的多样性探讨

为了探讨金属类配合物与肿瘤相互作用的多样性,需要了解人体宿主细胞的复杂性,了解变异细胞肿瘤的发生与发展、种类及其多样性特点;分析了化学药物治疗肿瘤的多样性和选择性以及联合用药的局限性;介绍了治疗肿瘤理论的研究现状,指出肿瘤特别是恶性肿瘤的多样性特点和化学药物治疗肿瘤的多样性及联合用药的局限性是肿瘤难治的根本原因。研究指出,环境因素和生活习惯带来的人体内微量元素的缺乏或过量的影响也是很重要的。在此基础上提出了治疗肿瘤理论的多样性观点。     

Construction of customized redundant multiwavelet via increasing multiplicity for fault detection of rotating machinery

Fault detection from the vibration measurement data of rotating machinery is significant for avoiding serious accidents. However, non-stationary vibration signal with a large amount of noise makes this task challenging. Multiwavelet not only owns the advantage on multi-resolution analysis but also can offer multiple wavelet basis functions. So it has the possibility of detecting various fault features preferably. However, the fixed basis functions which are not related to the given signal may lower the accuracy of fault detection. Moreover, another major intrinsic deficiency of multiwavelet lies in its critically sampled filter-bank, which causes shift-variance and is harmful to extract the feature of periodical impulses. To overcome these deficiencies, a new method called customized redundant multiwavelet (CRM) is constructed via increasing multiplicity (IM). IM is a simple method to design a series of changeable multiwavelet which are available for the subsequent optimization process. By the rule of the envelope spectrum entropy minimum principle, optimal multiwavelet is searched for. Based on the customized multiwavelet filters, the filters of CRM can be calculated by inserting zeros. The proposed method is applied to analyze the simulation, gearbox and rolling element bearing vibration signals. Compared with some other conventional methods, the results demonstrate that the proposed method possesses robust performance in detecting fault features of rotating machinery.     

一种同时求多项式所有零点及其重数的混合并行策略（英文）

本文提出一种计算多项式所有重零点及其重数的混合并行迭代策略.新算法包括两个部分:粗略计算部分和加速计算部分.在第一部分中,我们利用一种局部2阶收敛的方法求出所有低精度重根和重数;在第二部分中我们提出一种新的Gargantini型迭代法并证明新方法是局部4阶收敛.利用这种新方法对已求出的低精度重根进行加速.最后用数值算例验证新策略的有效性和优越性.     

Bounds for the Vanishing Order for Solutions of a Linear Differential System

We provide upper bounds for the order of vanishing of a polynomial restricted to a solution of a linear differential system through a nonsingular point. We deduce an estimate on the maximum order of inflection of the trajectories of a linear nonautonomous vector field.     

论中国特色城市规划

中国特色城市规划是中国特色社会主义的重要组成部分。虽然在城市规划的物质因素领域，将主要向全球化发展，但在人文因素领域和综合性方面，必将并已开始出现特色。应该充分发挥“主人”与“匠人”紧密结合的综合优势当好“龙头”。人情和人情味天人合一等七大古代传统特色将直接或经过扬弃封建迷信糟粕，推陈出新有机融入现代特色中来。多元化将是现代城市最突出的体现。     

Input Multiplicity Analysis in a Non‐Isothermal CSTR for Acid‐Catalyzed Hydrolysis of Acetic Anhydride

Multiplicity analysis gives practical guidance for process design to eliminate difficult operating regions associated with input and output multiplicities. Continuous stirred tank reactors (CSTRs) present challenging operational problems due to complex behavior such as input and output multiplicities, ignition/extinction, parametric sensitivity, and nonlinear oscillations. In the absence of a unified mathematical theory for representing various nonlinear system characteristics, the present study was aimed at understanding the dynamic behavior of CSTRs by means of experiments and to link the experimental data to theoretical considerations for further detection and elimination of operating problems. Theoretical modeling and analysis of a non‐isothermal CSTR with acid‐catalyzed hydrolysis of an acetic anhydride system for input multiplicity are discussed. Theoretical modeling of a non‐isothermal CSTR using a root‐finding technique was carried out for predicting steady‐state temperatures. Alternatively, a mathematical model for a non‐isothermal CSTR using unsteady‐state mass and energy balance equations is proposed. Computer‐based simulation was carried out using a program developed in MATLAB for final transient temperature and time‐temperature data of the CSTR system under investigation. The results of a theoretical analysis conducted for confirming the existence of input multiplicity in non‐isothermal CSTRs with acid‐catalyzed hydrolysis of acetic anhydride were compared with experimental investigations for validation.