基于数据采集卡和组态软件的PLC控制系统仿真

以基于PLC的液气联调试验台为背景,针对PLC控制系统存在现场调试难度大、组织投入大量人力物力、风险大等问题,采用数据采集卡和组态软件开发用于PLC程序调试的仿真系统,其由PLC、接口板和PC机组成,PLC的I/O信号通过接口板与PC机中的数据采集卡相连,在PC机中,用组态软件模拟试验台测试工况,实现试验台控制程序的仿真调试。实践表明,该系统减少了现场调试工作量,提高了开发效率。     

会议信息（二）

由丙二腈(MN)合成3-氨基-4-偕氨肟基呋咱的反应机理,已有文献建议为下述四步： 亚硝化、重排、肟化和脱水环化。本研究以原位红外跟踪了亚硝化这一步,检测到2-亚硝基丙二烯(NMN)及2-肟基丙二腈(OMN)这一对异构体。此外,得到了—NO、 NOH和—OH的三维原位红外图谱及—NO、CN和—OH在亚硝化过程中特征峰强度的变化,这有助深入了解亚硝化过程。不过,实验未能分离出OMN。NaOMN作为MN与NaNO₂反应的产物,1,3-二氨基-1,2,3-三肟基丙烷作为OMN钠盐(NaOMN)与NH₂OH的产物,两者均被成功地分离,并以IR、NMR、MS和元素分析证实。根据上述实验结果,提出了一个五步反应机理：硝化、重排、成盐、肟化及脱水环化。     

超声法检测火药生产中非金属杂质的应用研究

火药生产中非金属杂质带来的安全隐患是一个尚未解决的关键问题;由于超声检测具有适应性强,检测灵敏度高、快捷,无污染,可达到无损检测等特点,选用其作为检测火药生产药料中非金属杂质的方法;对A扫描脉冲反射法应用于检测药料中杂质进行了探索研究,试验结果证实用超声法检测药料中的非金属杂质具有一定可行性.     

用计算奇异值摄动方法简化复杂化学反应动力学模型

介绍了用于简化化学反应动力模型的计算奇异值摄动方法(CSP),给出了其基本思想与具体计算方法,然后用该方法来对一氧化碳／氢气在空气中燃烧的化学反应、激波管中甲烷的点火燃烧反应实例进行了简化。从计算结果看,CSP方法是一种比较有效的化学反应模型简化方法,用该方法简化得出的简化模型不仅减少了微分求解的组分数目,而且保持了较高的计算精度,能有效提高计算效率,具有较强的工程实际价值。     

New insight into the formation and oxygen barrier mechanism of carbonaceous oxide interlayer in a multicomponent carbide

Early transition metal carbides are considered to be superior candidate materials for oxidizing environments at temperatures exceeding 2000°C. Generally, the remarkable oxidation resistance is largely attributed to a carbonaceous oxide interlayer (eg, Hf–O–C, Zr–O–C, and Ta–O–C), located at the interface between the external oxide layer and internal carbide (eg, HfC, ZrC, and TaC), acting as the primary oxygen barrier. However, the oxygen barrier mechanism of the carbonaceous oxide interlayer remains unclear. Herein, through studying the oxidation behavior of a novel multicomponent carbide Hf_0.5Zr_0.3Ti_0.2C in oxidizing environments up to 2500°C, the oxygen barrier mechanism of the carbonaceous oxide was recently revealed. We found that the oxygen barrier resulted from the slow oxygen diffusion through the inner grains of Hf-Zr–Ti–O due to the presence of carbon formed at the grain boundaries because of the existence of compact external oxide layer, beneath which the Hf–Zr–Ti–O–C interlayer possesses much lower oxygen activity and temperature that allow carbon to exist stably. This as-formed carbon strongly retarded the fast diffusion of oxygen along the grain boundaries of oxides. Additionally, desirable synergisms of the designed multicomponent system, particularly, the outward short-circuit diffusion of Ti, lead to the self-healing of the external oxide layer, evidently enhancing integral protection performance against oxidizing environments.     

Strengthen flame retardancy of epoxy thermoset by montmorillonite particles adhering phosphorus-containing fragments

Phosphaphenanthrene derivative tri-(3-DOPO-2-hydroxypropan-1-yl)-1,3,5-triazine-2,4,6-trione (TGD) and organo-modified montmorillonite (OMMT) were jointly introduced into the diglycidyl ether of bisphenol A cured by 4,4-diamino-diphenylmethane (EP) to investigate their flame retardant behaviors. With only addition of 0.5%OMMT and 2.5%TGD, epoxy thermoset achieved a limiting oxygen index value of 33.7% and passed UL 94 V-0 rating test. Compared with the combustion behaviors of 3%OMMT/EP and 3%TGD/EP, an obvious synergistic flame retardant effect between OMMT and TGD can be concluded in OMMT/TGD/EP. Meanwhile, the FTIR spectra of gas-phase and condensed-phase products further proved this synergistic effect working in a physical way. On one hand, the co-existence of hydroxyl-containing TGD enabled montmorillonite (MMT) particles to filtrate and adhere more smoke fragments. On the other hand, the co-action of MMT help the polar phosphorus-containing fragments from TGD better strengthened char layer, enhancing the barrier and protective effect of residue. The synergistic flame retardant effect from OMMT/TGD system endowed themselves with higher flame retardant efficiency, and epoxy thermoset with better flame retardant performance. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 47500.     

旋转空化器中减速板作用的数值仿真研究

旋转空化器是通过在水中高速转动的叶片产生可控超空泡的装置,以此来实现超空泡的利用.前人对于超空泡的研究表明,产生超空泡所需的转速比较大.本文将减速板加入到旋转空化器中,并采用数值仿真的方法,对减速板的工作特性进行分析.研究结果表明,带减速板的旋转空化器产生超空泡的转速得到很明显的降低,产生超空泡的尺寸也明显增大.而减速...     

某高层工业框架结构弹塑性分析及性能化抗震加固设计

通过对某高层工业框架结构进行小震、中震、大震下的弹性及弹塑性分析研究,得出了既有建筑物现阶段的实际抗震性能,并在此基础上尝试采用了目前国际上较先进的基于抗震性能目标的性能化抗震设计理论,对既有建筑物抗震加固设计提供了不同性能目标下的不同加固方案,并且对各个方案逐一进行分析对比,最终确定一种安全、适度、适用、可实施性强、经济合理的加固方案进行抗震加固设计。     

边坡防护用椰壳纤维复合植物纤维毯的制备及性能表征

为研究不同椰壳纤维质量分数下植物纤维毯的储水性能及移植后植物的生长情况,制备了3种不同椰壳纤维质量分数的储水层,将其与非织造表层和复合种子层复合,开发出一种新型植物纤维毯.测试了植物纤维毯的储水能力与植物生长情况,以及生物质结皮对其性能的影响.试验结果表明,植物纤维毯的储水能力及植物生长情况随着储水层中椰壳纤维质量分数...