Microstructure,phase stability and mechanical properties of Nb–Ni–Ti–Co–Zr and Nb–Ni–Ti–Co–Zr–Hf high entropy alloys

Owning to their excellent thermal stability and high strength at elevated temperature,high entropy alloys(HEAs) possess great potential for the application in aviation and aerospace fields.In present work,two novel Nb-Ni-Ti-Co-Zr and Nb-Ni-Ti-Co-Zr-Hf HEAs were prepared by arc melting and copper mold suction-casting method.The microstructure,phase stability,mechanical properties at room temperature and elevated temperature of the two HEAs were studied.Both of the HEAs possess high yield stress at room temperature,especially for the Nb-Ni-Ti-Co-Zr(with 2331 Mpa).In addition,the Nb-Ni-Ti-Co-Zr HEA exhibited high yield stress of 564 Mpa at elevated temperature of 800 ℃ and large compressive plastic strain(more than 50%at 800 ℃).Nb-Ni-Ti-Co-Zr-Hf alloy showed new phase precipitation at 800 ℃,whereas the structure of Nb-Ni-Ti-Co-Zr was more stable,which is one of the reason why it possesses high strength at room temperature and elevated temperature.The high temperature properties of the Nb-Ni-Ti-Co-Zr HEA make it promising for high temperature application.     

Robust predictive control of polytopic uncertain systems with both state and input delays

A robust model predictive control algorithm for discrete linear systems with both state and input delays subjected to constrained input control is presented,where the polytopic uncertainties exist in both state matrices and input matrices.The algorithm optimizes an upper bound with respect to a state feedback control law.The feedback control law is presented based on the construction of a parameter-dependent Lyapunov function.The above optimization problem can be formulated as a LMI-based optimization.The feasibility of the optimization problem guarantees that the algorithm is robustly stable.The simulation results verify the effectiveness of the proposed algorithm.     

技术能源网络MIS

本文介绍企业技术能源网络ＭＩＳ的网络环境，系统的软、硬件构成，设计思想，技术特点和实现策略。     

羧甲基纤维素钠水溶液稳定性及其对胶体的保护性能

羧甲基纤维素钠(CMC)是一种高分子电解质,作为保护胶体在医药、食品、石油、纺织、印染等领域均有广泛的应用。不同取代度和聚合度的CMC在一定浓度的乙醇水溶液中溶解性能不同。本文利用这个原理对CMC分级。测定织物整理用的活性碳悬浮液的相对聚结量⊿f值的结果表明,在本实验中具有较低取代度和较高聚合度的级分对胶体的保护性能较好。 CMC水溶液的存放性能很不稳定,主要原因是在外界因素作用下分子链断裂,因此特性粘度下降。在存放降解过程中CMC对胶体的保护性能开始有所上升,然后逐渐下降。存放时温度升高会大大加速CMC对胶体保护性能下降的过程。     

非齐次Poincare’标架丛、配丛以及它们的联络

本文给出了结构群ISO(3,1)元素左右作用的两种不同表示。用矩阵乘法定义了群元素的左、右作用以及它们对矢量和标架的左、右作用,规定了将仿射标架分解为矩阵组合的一种形式,并用一种新的方法定义结构群对积流形P×M′的作用,从而建立了新的非齐次Poincare′标架丛P(M)及其配丛E(M)。     

计算机自动查套定额系统研究

本文首先分析了人工查套定额的方法,然后结合《煤炭井巷工程预算定额》提出了计算机代替人自动查套定额的程序系统设计方法。这一方法使施工图预算软件具有了初步智能,从而提高预算编制的自动化程度和结果的准确性.     

一种铂热电阻测温电路参数的计算方法

提出用加权最小二乘法计算一种正反馈放大电路的参数，用以线性化铂热电阻温度传感器，这种算法使用简单、计算速度快、精度高。应用此法计算的电路参数使铂热电阻在－２００℃－＋６５０℃温度范围内线性化精度达０．０５８％ＦＳＲ。     

钙及钙调素研究进展(Ⅰ)

解决细胞识别、细胞通讯、细胞代谢的调控、细胞增殖与细胞周期、细胞与抗病以及细胞对外界信号进行的持续反应维持等重大理论与实际问题。文中着重介绍了作为胞内信使的钙离子及其循环的重要意义、作为Ca~(2+)受体的胞内蛋白CaM的广泛性。作者认为CaM在细胞代谢调控中处于中心位置,对Ca~(2+)及其循环、第二信使系统CAMP和肌醇磷脂,甚致CGMP均有调节、协调作用;是调控细胞代谢的综合剂。