彩板涂料固化温度曲线的测定

在卷材有机涂层钢板生产中，涂料的固化温度是影响产品质量的重要因素。使用BYKOTRACK和GRADIENT－OVEN测出不同基板、不同涂料的固化温度曲线，并控制固化过程温度参数，可使每次生产都获得最佳固化温度，此而大大减少废、次品，经济效益十分显著。     

Solution of the point reactor kinetics equations with temperature feedback by the ITS2 method

The ITS2 method is used to solve the point-reactor kinetics equations in the integral formulation with arbitrary number of delayed neutron groups and Newtonian temperature feedback. The method is based on low-order Taylor series expansions of neutron density and reactivity functions and uses variable time steps to control the numerical instabilities resulting from the stiff nature of the governing equations. Time steps are determined through an analytic criterion relating their magnitudes to the maximum admissible truncation error in the neutron-density expansion series. Temperature feedback is included in the reactivity as a function of the neutron density for different input types, including step change with adiabatic temperature feedback and compensated ramp functions. An iterative procedure is applied to determine the time steps while simultaneously updating the reactivity function. Numerical results show the ITS2 method is highly accurate for solving point reactor dynamics problems with temperature feedback.     

An improved thermometer for intermediate-mass fragments

An improved thermometer (TIB) is proposed for intermediate-mass fragments via the difference between isobaric yield ratios. The residual free energy of three isobars is replaced by that of the binding energy. The measured fragments in the 140A MeV 40, 48Ca+ 9Be (181Ta) and 58, 64Ni+ 9Be (181Ta) reactions are analyzed to obtain TIB ranging from 0.6 to 3.5 MeV. TIB is suggested to be a direct determination of temperature avoiding the fit-ting procedure.     

基于遗传算法的啤酒发酵温度优化控制

在分析啤酒发酵工艺流程及控制要求的基础上,针对发酵过程中温度控制的系统特性,提出了一套完整的温度优化控制方案。在过程控制系统中,引入遗传算法对PID参数进行优化。在迭代计算中采取最优保留策略,保证个体最终收敛于全局最优;为实现理想的温度控制效果,在误差绝对值时间积分型目标函数中设置了控制量的平方项和超调惩罚项。实验结果表明:系统响应快速,温度超调比单纯的PID控制算法显著减少,动、静态特性较为理想。     

智能压力传感器

讨论了压阻式智能传感器的设计,并以80C31单片机为核心构成了一个能检测压力、温度的智能传感器,它能实现量程的自动变换、故障的自诊断及数据的处理,通过软件实现了对半导体传感器的零点修正、非线性修正及温度补偿。实验表明,传感器的智能化改善了传感器的性能。     

飞机自动灭火电路的设计与仿真

针对飞机仪表、电气设备和输油系统等重要装置防火的需要,以热电阻为传感器,基于新型单片机AT89S51设计了自动灭火电路。先将热电阻采集的温度信号放大为电压信号,再通过最小二乘法拟合建立温度与输出电压间的定量关系,然后将温度信息的模拟电压送入芯片ADC0832进行A／D转换。所得的数字信号被送入单片机,由软件根据含温度信息的数字信号进行处理,并判断是否驱动灭火器引爆装置。Proteus仿真结果表明,系统检测结果精确,工作运行可靠。     

南京新城大厦超长混凝土结构温度应力分析与设计

文章结合南京新城大厦工程,利用有限元软件对超长混凝土结构收缩和温差引起的内力进行模拟,得出了温降作用下结构内部温度应力的大小及其分布规律,从而对超长结构的温度作用进行了探讨,并提出无粘结预应力钢筋抵抗温度应力的方法以及施工设计中常见问题的解决方法,可为类似工程提供参考。     

Effect of environmental daily temperature fluctuations over one year storage on the prediction of non-enzymatic browning in reduced-moisture foods stored at “ambient” temperature

Non-enzymatic browning predictions in reduced-moisture foods stored over one year at “ambient” temperature, were made using, (a) realistic environmental daily (and seasonal) temperature fluctuations, and (b) a constant mean temperature. Daily temperature records taken every 6 h from January 1st to December 31st (1460 temperature data) in four selected cities from Argentina, were used.

The predicted amount of browning over one year storage was different depending whether the annual mean temperature (T_am), the monthly mean temperature (T_mm) or the daily temperature fluctuations (T_df) were used for the predictions. Predicted browning over one year was generally higher when realistic storage conditions (i.e., daily/seasonal temperature fluctuations) rather than mean values (annual or monthly), were used instead.     

涂层炉新型搁丝槽的设计

涂层炉电热丝制作安装难度大,维修成本高。本文给出了一种新型的电热丝搁置槽,通过仿真发现,这种搁丝槽能够保证炉膛内温度场的均匀性,而且使电热丝的制作和安装更方便,降低了维修成本。     

Analysis of the inverse identification of constitutive equations applied in orthogonal cutting process

Flow stress identification of work-piece materials for its use in machining operation simulation models has been long treated. The interest in defining the flow stress in an easy and fast way without using complicated dynamic characterization tests leads to analyse the inverse identification of flow stress employing cutting operations. This paper presents a revision of different aspects concerning the inverse algorithms applied to the primary shear zone (PSZ). It also presents a new approach for studying material's behaviour on the secondary shear zone (SSZ) where experimentally measured temperatures have been included in the inverse algorithm. Two steels, 42CrMo4 and 20NiCrMo5 are employed and finite element method (FEM) simulations are carried out in order to evaluate the usefulness of the calculated flow stress laws and proposed algorithm.