球型支座应用于大型渡槽的隔震研究

结合实际大型渡槽工程,设计球型隔震支座NKQZ15000GD,该支座具有较高的竖向承载能力、较低的水平剪切刚度,并具有一定阻尼和复位能力;对该支座进行材料性能测试,拟合支座的力学性能参数;分别采用反应谱法和动力时程法,计算隔震渡槽在设计地震与超设计地震作用下的动力反应;分析球型隔震支座应用于大型渡槽的减震效果,根据定量分析的结果得到一些规律性的结论。     

Towards inverse modeling of turbidity currents: The inverse lock-exchange problem

A new approach is introduced for turbidite modeling, leveraging the potential of computational fluid dynamics methods to simulate the flow processes that led to turbidite formation. The practical use of numerical flow simulation for the purpose of turbidite modeling so far is hindered by the need to specify parameters and initial flow conditions that are a priori unknown. The present study proposes a method to determine optimal simulation parameters via an automated optimization process. An iterative procedure matches deposit predictions from successive flow simulations against available localized reference data, as in practice may be obtained from well logs, and aims at convergence towards the best-fit scenario. The final result is a prediction of the entire deposit thickness and local grain size distribution. The optimization strategy is based on a derivative-free, surrogate-based technique. Direct numerical simulations are performed to compute the flow dynamics. A proof of concept is successfully conducted for the simple test case of a two-dimensional lock-exchange turbidity current. The optimization approach is demonstrated to accurately retrieve the initial conditions used in a reference calculation.     

Design of experiments for bivariate binary responses modelled by Copula functions

Optimal design for generalized linear models has primarily focused on univariate data. Often experiments are performed that have multiple dependent responses described by regression type models, and it is of interest and of value to design the experiment for all these responses. This requires a multivariate distribution underlying a pre-chosen model for the data. Here, we consider the design of experiments for bivariate binary data which are dependent. We explore Copula functions which provide a rich and flexible class of structures to derive joint distributions for bivariate binary data. We present methods for deriving optimal experimental designs for dependent bivariate binary data using Copulas, and demonstrate that, by including the dependence between responses in the design process, more efficient parameter estimates are obtained than by the usual practice of simply designing for a single variable only. Further, we investigate the robustness of designs with respect to initial parameter estimates and Copula function, and also show the performance of compound criteria within this bivariate binary setting.     

峰值电流模升压转换器的动态斜坡补偿电路设计

基于HHNEC 0.35 μm BCD工艺设计了一种应用于峰值电流模升压转换器的动态斜坡补偿电路.该电路能够跟随输入输出信号变化,相应给出适当的补偿量,从而避免了常规斜坡补偿所带来的系统带载能力低及瞬态响应慢等问题.经Cadence Spectre验证,该电路能够达到设计要求.     

钢包精炼炉电极调节器的控制原理及应用

主要介绍了唐钢一钢轧厂3#LF钢包精炼炉电极调节器控制原理,以电弧阻抗为控制变量,使其调节特性、节约电能、缩短冶炼时间等指标有更好的提高.     

基于感应电机状态方程的定子电阻辨识方法的研究

基于感应电机两相同步旋转坐标系状态方程,提出了一种新的定子电阻辨识方案。在分别利用励磁电流微分方程和转矩电流微分方程推算转速的基础上,利用二者的等量关系实现了定子电阻在线辨识。该方案的优点是,定子电阻估算仅需要电机终端可测的定子电压、电流,无须借助转子或定子磁链。仿真实验将其应用于无速度闭环矢量调速系统,实时更新转速估算模块中的定子电阻,论证了该方案对电机参数变化鲁棒性强及对改善转速估算精度的有效性。     

皮肤流电响应监护系统与PC串口通信的设计

运用Visual Basic6.0开发了一套基于皮肤流电响应信号(GSR)的波形显示及分析系统.介绍了自行研制的皮肤流电响应硬件监护系统的硬件组成,利用VB中的MSComm控件实现计算机与GSR监护系统的串行通信,给出了详细的程序设计过程.     

基于高边电流检测驱动LED

研究了一种采用高边电流检测的滞环控制LED恒流驱动芯片。基于0．5um5V／18V／40VCDMOS．工艺,运用HSPICE工具对电路进行仿真,仿真结果显示：在4．5V～28V电源电压范围内,-40℃～＋l25℃工作温度范围内,电路可为LED提供恒定的350mA驱动电流,LED驱动电流为滞环变化的三角波,最大误差为6．2％。通过调节外部信号DIM的占空比可以调节LED的亮度。     

高灵敏度金属分离器传感线圈的设计

分析了电感线圈探测金属的理论,针对传统的金属探测传感器灵敏度低,抗干扰能力差和结构复杂的缺点,根据电磁感应原理提出了一种具有高探测精度和高抗干扰能力的新型金属探测传感器,并描述了其结构和材料设计方案。最后用试验验证了设计思想和设计方案的正确性和实用性。     

基于步进电机的工程车倾动装置模糊控制系统

在针对工程车上对倾动装置的高精度易操作的要求,开发出了一种基于两相混合式步进电机的高精度自调整模糊控制系统.为提高系统的定位精度,设计出了一种基于D/A转换器、集成脉宽调制控制芯片SG3525和GAL20V8等器件的步进电机斩波恒流细分驱动系统.并将模糊推理机制和常规PID控制结合起来,优化了驱动系统的控制参数及控制性能.为改善电机转动的平稳性,采用了抛物线升降频法对电机速度进行调节.整个系统定位精确,性能稳定,安全可靠.