高强钢梁柱外伸式端板节点常温与火灾后性能参数分析

为了解端板厚度、螺栓直径、螺栓预紧力、柱翼缘厚度、端板钢材强度及过火温度等因素对高强钢端板连接节点力学性能的影响,对薄高强钢端板替代厚普通钢端板这一设计理念进行深入探讨,采用ABAQUS对高强钢端板连接节点进行有限元分析.有限元分析结果表明:端板厚度增加,节点的初始转动刚度和极限承载力提高,转动能力下降;螺栓直径增加,节点的初始转动刚度、极限承载力及转动能力均提高;螺栓预紧力增加,节点的初始转动刚度提高,极限承载力和转动能力基本不变;柱翼缘厚度增加,节点的初始转动刚度提高,极限承载力基本不变,转动能力略有减小;端板钢材强度增加,节点的初始刚度基本不变,极限承载力提高,转动能力在端板钢材强度不超过Q460时基本不变,高于Q460后显著减小;与采用较厚普通钢端板的节点相比,采用薄高强钢端板的节点常温下和火灾后均可达到相似的承载力、相近甚至更高的转动能力;端板连接节点火灾后可能发生失效模式转变,甚至由延性转变为脆性的失效模式.     

A Review of the System-Intrinsic Nonequilibrium Thermodynamics in Extended Space (MNEQT) with Applications

The review deals with a novel approach (MNEQT) to nonequilibrium thermodynamics (NEQT) that is based on the concept of internal equilibrium (IEQ) in an enlarged state space SZ involving internal variables as additional state variables. The IEQ macrostates are unique in SZ and have no memory just as EQ macrostates are in the EQ state space SX⊂SZ. The approach provides a clear strategy to identify the internal variables for any model through several examples. The MNEQT deals directly with system-intrinsic quantities, which are very useful as they fully describe irreversibility. Because of this, MNEQT solves a long-standing problem in NEQT of identifying a unique global temperature T of a system, thus fulfilling Planck’s dream of a global temperature for any system, even if it is not uniform such as when it is driven between two heat baths; T has the conventional interpretation of satisfying the Clausius statement that the exchange macroheatdeQflows from hot to cold, and other sensible criteria expected of a temperature. The concept of the generalized macroheat dQ=deQ+diQ converts the Clausius inequality dS≥deQ/T0 for a system in a medium at temperature T0 into the Clausius equalitydS≡dQ/T, which also covers macrostates with memory, and follows from the extensivity property. The equality also holds for a NEQ isolated system. The novel approach is extremely useful as it also works when no internal state variables are used to study nonunique macrostates in the EQ state space SX at the expense of explicit time dependence in the entropy that gives rise to memory effects. To show the usefulness of the novel approach, we give several examples such as irreversible Carnot cycle, friction and Brownian motion, the free expansion, etc.     

Improved Nonlinear Extended State Observer-Based Sliding-Mode Rotary Control for the Rotation System of a Hydraulic Roofbolter

This paper develops a sliding-mode control with an improved nonlinear extended state observer (SMC-INESO) for the rotation system of a hydraulic roofbolter with dead-zones, uncertain gain, and disturbances, with the purpose of improving tracking performance. Firstly, the rotation system is modeled to compensate for dead-zone nonlinearity. Then, we present an improved nonlinear extended state observer to estimate disturbances of the rotation system in real time. Moreover, a proportional-integral-differential sliding-mode surface is introduced and an improved sliding-mode reaching law is designed. Based on this, a sliding-mode control law is developed. In order to eliminate the influence of estimation error and uncertain gain, we design two adaptation laws based on the sliding-mode surface and the estimated states. Finally, the effectiveness of the proposed SMC-INESO is verified through comparative simulation studies.     

自适应设计广义线性回归多维拟似然估计的渐近正态性

本文研究了自适应设计下广义线性回归的拟似然方程∑ni=1xi(yi-μ(xi′β))=0,其中yi是q维向量,xi是p×q阶随机矩阵,在一定条件下证明了方程的解^βn具有渐进正态的性质.     

面向汽车产业链的企业业务集成平台

对汽车产业链企业业务集成平台的需求进行分析,建立以整车制造厂为核心的汽车产业链扩展企业模型.提出基于网络化制造和ASP理论的汽车产业链业务集成平台整体解决方案,设计可定制的能支持多个扩展企业业务协作的系统框架.研究平台的体系结构及系统部署方案,提出基于Web Services业务集成与数据交换解决方案.     

陀螺内部摩擦对旋转物体等效原理检验的影响

利用角动量定理对实验采用的电磁驱动机械陀螺的内部摩擦力矩进行测量,分析了这一摩擦力矩对宏观旋转物体等效原理扭秤方案检验的影响,并就此提出了几项改善措施.实验结果表明:该摩擦力矩正比于陀螺的角速度,当陀螺旋转的角速度达到17 000 r/min时,陀螺内部摩擦力矩达到1×10-4N.m,这一大小对宏观旋转物体等效原理检验扭秤方案的预期精度给出了严格限制.     

Mobile robot simultaneous localization and map building based on improved particle filter

0IntroductionA key prerequisite for a truly autonomous mobilerobot is that it can localize itself and accurately map itssurroundings[1],which is known as Simultaneous Local-ization and Mapping(SLAM),and has received consider-able attentionrecently.The first successful attempt at the SLAMproblemwas introduced by Smith who proposed usingthe extendedKalmanfilter(EKF)forincrementally estimatingthe pos-terior distribution over robot poses[2].One of the limita-tions of the EKFis that it requ…     

扩展琼斯矩阵在研究Solc滤波器离轴消光比中的应用

根据广泛使用的双折射材料的性质以及滤波器入射角有限的特点,讨论了晶体中o光和e光的关系;根据光的折射定律,将光在晶体表面的折射效果表述为输入、输出折射率矩阵;建立了从入射面坐标系到晶体本征坐标系的坐标变换矩阵;推出了简化的扩展琼斯矩阵。整个过程物理思想清楚,每个矩阵表示的物理意义直观、明确,得到的结果简单,计算量小。用于Solc滤波器消光比的研究,给出了在任意入射角下计算多块晶片Solc滤波器传输特性的一般表达式,对Solc滤波器锥光干涉图作了数值模拟。适用于计算各种类型双折射滤波器的离轴消光比。     

活动星系核的核主导系数与光度关系研究

从多篇文献中收集了402个活动星系核(AGN)的有关数据,研究了AGNs样本的核主导系数与核心光度及延展元光度的关系.结果显示:核主导系数与核心光度之间存在强线性相关,相关系数r=0.692,置信度P<10-4,而核主导系数与延展元光度之间不存在相关.所得结果支持AGN的相对论喷流模型.     

近似诣零根环的遗传性和特殊性

证明了近似诣零根对子环遗传等价于 Ｋｏｅｔｈｅ 猜测,给出了半单纯环是半单纯质环的不可缩短的亚直和的条件