Modeling and analysis of rigid multibody systems with driving constraints and frictional translation joints

An approach is proposed for modeling and anal- yses of rigid multibody systems with frictional translation joints and driving constraints. The geometric constraints of translational joints with small clearance are treated as bilat- eral constraints by neglecting the impact between sliders and guides. Firstly, the normal forces acting on sliders, the driv- ing constraint forces （or moments） and the constraint forces of smooth revolute joints are all described by complementary conditions. The frictional contacts are characterized by a set- valued force law of Coulomb＇s dry friction. Combined with the theory of the horizontal linear complementarity problem （HLCP）, an event-driven scheme is used to detect the transi- tions of the contact situation between sliders and guides, and the stick-slip transitions of sliders, respectively. And then, all constraint forces in the system can be computed easily. Secondly, the dynamic equations of multibody systems are written at the acceleration-force level by the Lagrange multiplier technique, and the Baumgarte stabilization method is used to reduce the constraint drift. Finally, a numerical example is given to show some non-smooth dynamical behaviors of the studied system. The obtained results validate the feasibility of algorithm and the effect of constraint stabilization.     

聚电解质层层自组装线性多层膜的电荷分区互补理论建立及膜内聚电解质离子化率

提出了聚电解质层层自组装线性多层膜的电荷分区互补理论,基于该理论建立了表面电荷密度、诱导电荷、聚电解质的吸附量和形态、膜内电荷存在形态之间的半经验数学模型。提出了计算膜内聚苯乙烯磺酸钠（PSSS）与聚烯丙基胺盐酸盐（PAH）的离子化率和电荷诱导效应的方法,讨论了处于最外层和次外层聚电解质的离子化率的不同及其与聚电解质强弱的关系。该方法比红外光谱法和光电子能谱法更简便,可用于研究所有聚电解质的离子化率。     

Componentwise complementary cycles in multipartite tournaments

The problem of complementary cycles in tournaments and bipartite tournaments was completely solved. However, the problem of complementary cycles in semicomplete n-partite digraphs with n ≥ 3 is still open. Based on the definition of componentwise complementary cycles, we get the following result. Let D be a 2-strong n-partite (n ≥ 6) tournament that is not a tournament. Let C be a 3-cycle of D and D \ V (C) be nonstrong. For the unique acyclic sequence D1, D2, ··· , Dα of D \V (C), where α≥ 2, let Dc = {Di|Di contains cycles, i = 1, 2, ··· , α}, Dc = {D1, D2, ··· , Dα} \ Dc. If Dc ≠ , then D contains a pair of componentwise complementary cycles.     

非线性互补问题的组合同伦算法

针对拟P_*-映射和P(τ,α,β)-映射所对应的非线性互补问题,本文对其解的存在性及有效求解算法进行了研究.文中利用组合同伦方法给出了这两类非线性互补问题存在有界解的构造性证明,并利用预估校正方法对同伦路径进行跟踪,得到了互补问题的解.通过数值算例验证了该算法的有效性.     

大规模非线性互补问题的共轭梯度法

提出求解大规模非线性互补问题NCP(F)的PRP型共轭梯度法,算法自然满足充分下降条件.当F是可微P_0+R_0函数且F'(χ)在水平集上全局Lipschitz连续条件下,证明了算法的全局收敛性.数值结果表明算法的有效性.     

数字微镜光谱仪的互补S编码矩阵的设计及实验

数字微镜光谱仪在应用中编码矩阵的选取至关重要。最佳的理论编码矩阵H矩阵存在非循环、编码复杂、双光路系统实现困难的问题而得不到广泛应用;而最佳实用S矩阵较H矩阵信噪比提高优势略逊。为此本文针对数字微镜光谱仪设计了一种互补S编码矩阵,介绍了其构造、实现过程以及对杂散光和暗电流噪声的削弱作用,通过对其噪声改善程度理论的分析,说明该算法结合了H矩阵与S矩阵的优点,达到了理论与实用的双优。经实验验证,该算法较S矩阵编码模板信噪比提高了2.05倍。     

小型风光互补发电演示装置

研制了适用于大学物理演示实验教学的小型风光互补发电演示装置,该装置由叶片、风力发电机、光伏太阳能电池板、控制器、蓄电池、逆变器、负载等几部分组成.整个系统以光电互补控制器为核心,经由风力发电机与光伏太阳能电池板将风能和太阳光能转变为电能,并将其储存于蓄电池中供负载使用.该装置展示了风力发电系统的组成,演示了风力发电原理和相关空气动力学原理.     

数字域时间延迟积分时间CMOS相机高分“凝视”成像设计分析

为实现凝视卫星高分跟踪成像,设计了数字域时间延迟积分(TDI)互补金属氧化物半导体(CMOS)传感器在凝视姿态下的成像匹配模型,推导了卫星凝视跟踪成像时相对轨道坐标系的姿态变化,采用坐标变换方法实时计算其在凝视过程中随姿态变化的行转移时间,利用蒙特卡罗方法统计计算了凝视模式下姿态指向精度和稳定度对成像的影响。利用数字域TDI CMOS原理样机和小卫星姿态控制系统全物理仿真平台对成像进行了仿真分析。结果表明,卫星的姿态控制精度在成像过程中会引起纵向的像移速度失配和横向匹配的残余像移,成像积分级数越高,图像信噪比越大。积分级数的增加对卫星姿态提出较高要求,仿真平台姿态角和姿态角速度控制精度分别优于0.05°,0.005°/s时,采用积分级数为48级能较好地满足成像质量要求。     

基于乘性模糊互补判断矩阵的FAHP

根据乘性一致性的定义,从人的主观判断与其权重的函数关系出发,获得了乘性模糊互补判断矩阵的元素表达式,论证了利用乘性模糊互补判断矩阵求取因素相对权重的可行性,最后给出了一种基于乘性一致模糊判断矩阵的排序方法.从而使得乘性模糊互补判断矩阵的应用的理论基础更加坚实.     

Complementarity properties of the Lyapunov transformation over symmetric cones

The well-known Lyapunov's theorem in matrix theory/continuous dynamical systems asserts that a square matrix A is positive stable if and only if there exists a positive definite matrix X such that AX +XA* is positive definite. In this paper, we extend this theorem to the setting of any Euclidean Jordan algebra V . Given any element a ∈ V , we consider the corresponding Lyapunov transformation La and show that the P and S-properties are both equivalent to a being positive. Then we characterize the R0 -property for La and show that La has the R0 -property if and only if a is invertible. Finally, we provide La with some characterizations of the E0 -property and the nondegeneracy property.