Second-order necessary optimality conditions for semilinear elliptic optimal control problems

This paper deals with the necessary optimality conditions for semilinear elliptic optimal control problems with a pure pointwise state constraint and mixed pointwise constraints. By computing the so-called ‘sigma-term’, we obtain the second-order necessary optimality conditions for the problems, which is sharper than some previously established results in the literature. Besides, we give a condition which relaxes the Slater condition and guarantees that the Lagrangian is normalized.     

梁在纯弯曲力矩作用下的动态塑性断裂

本文采用刚塑性分析方法,研究了带裂纹有限长韧性材料梁在纯弯曲力矩作用下的动态塑性断裂过程,本文考虑了由于断裂引起的附加轴向力对断裂过程的影响,并在分析中考虑了应变率对断裂过程的影响。文章给出了断裂过程中断裂截面上弯曲力矩和轴向力随时间的变化规律,以及裂纹长度,裂纹扩展速度和加速度随时间的变化规律。     

On an inverse problem of bending of a physically nonlinear inhomogeneous plate

An elastic plate with a physically nonlinear inclusion of an arbitrary shape is considered. This plate is subjected to pure bending under the action of transverse forces and bending moments applied at the external boundary of the plate. There are no loads distributed over the surface. The problem of finding external actions that provide a necessary uniform moment state in the inclusion, i.e., prescribed constant moments and curvatures, is formulated and solved. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 5, pp. 104–107, September–October, 2007.     

Approximate estimation of hardening-softening behaviour of circular pipes subjected to pure bending

An approximate method for describing the plastic hardeningsoftening behaviour of circular pipes subjected to pure bending is presented. Theoretical estimation based on the uniform ovalization model and local collapse model proposed in the paper is incorporated to give several simple formulations with reasonable accuracy for determining the relationship between bending moment (M) and curvature (k) in the purely bended pipes. Attention is focused on the critical curvature associated with maximum resistant moment and the maximum change in the original diameter before the end of uniform ovalization stage as well as the local collapse behaviour. Some comparisons between analytical results and experimental results are made in order to examine the theory.     

QCD因子化方法下_s→π~ π~-中湮没强度的探索

利用QCD因子化方法,并采用具有质量的有效胶子传播子来消除端点发散,计算了纯湮没衰变 Bs→π π-过程的CP平均分支比并对该过程的CP破坏进行了具体研究．结果表明:该过程的CP平均分支比为1．24×10-7,同时企鹅图对该过程起着主要贡献;Bs→π π-过程中直接CP破坏参数Cππ估算为-0．05,混合CP破坏参数Sππ比较大,可达到0．18．该过程在未来的LHC-b物理实验上是完全有可能被测量到的,通过对该过程的研究能够使我们更好地了解B介子无璨衰变的动力学机制和胶子的性质．     

极值问题与一类具有无限纯策略集的最优混合策略

证明了局部凸线性拓扑空间上实值连续泛函的极大极小定理与极大定理，并由此证明了一类具有无限纯策略集的二人对策中最优混合策略的存在性。该证明对经典情形也适用，而且比传统的证明要简洁。     

On Pure Quotients and Pure Subobjects

In the theory of accessible categories, pure subobjects, i.e. filtered colimits of split monomorphisms, play an important role. Here we investigate pure quotients, i.e., filtered colimits of split epimorphisms. For example, in abelian, finitely accessible categories, these are precisely the cokernels of pure subobjects, and pure subobjects are precisely the kernels of pure quotients.     

听阈曲线探究性实验

利用实验室现有的简单设备组成实验装置，测定了正常的听阈曲线、有噪声干扰时的听阈曲线、分散注意力时的听阈曲线．     

Curved exponential families of stochastic processes and their envelope families

Exponential families of stochastic processes are usually curved. The full exponential families generated by the finite sample exponential families are called the envelope families to emphasize that their interpretation as stochastic process models is not straightforward. A general result on how to calculate the envelope families is given, and the interpretation of these families as stochastic process models is considered. For Markov processes rather explicit answers are given. Three examples are considered some in detail: Gaussian autoregressions, the pure birth process and the Ornstein-Uhlenbeck process. Finally, a goodness-of-fit test for censored data is discussed.     

制备三量子位和四量子位核磁共振等效纯态

基于时间平均法,给出了在同核系统中制备三量子位和四量子位核磁共振等效纯态的方案.利用Λn(not)门,本文的方案大大减少了制备等效纯态所需的操作次数:在三同核系统中制备三量子位核磁共振等效纯态只需三次操作,在四同核系统中制备四量子位核磁共振等效纯态只需五次操作.然后在一个链状耦合的同核系统中实验制备三量子位核磁共振等效纯态,验证了本文的方案 并且给出了四量子位方案的模拟结果谱图