Extension of the GHJW theorem for operator ensembles

The Gisin-Hughston-Jozsa-Wootters theorem plays an important role in analyzing various theories about quantum information, quantum communication, and quantum cryptography. It means that any purifications on the extended system which yield indistinguishable state ensembles on their subsystem should have a specific local unitary relation. In this Letter, we show that the local relation is also established even when the indistinguishability of state ensembles is extended to that of operator ensembles.     

CFD simulation of oil–water separation characteristics in a compact flotation unit by population balance modeling

Huge amounts of produced water are generated in offshore oil production. The Compact Flotation Unit (CFU) is an excellent pretreatment technology of produced water with high separation efficiency, low residence, and small split ratio. The Computational Fluid Dynamics-population balance model (CFD-PBM) method is used in the present work to study the oil–water separation characteristics in the self-developed Beijing Institute of Petrochemical Technology Compact Flotation Unit (BIPTCFU) at both micro-scale and macro-scale, which would help us gain more insights into the mechanism and the influence of flow field on the oil–water separation process such as the oil droplets’ diameter distribution and separation efficiency. The effects of the inlet diameter, the height of the preliminary separation zone, and the width of the annular space on the oil–water separation characteristics of CFU were discussed systematically. It is illustrated that the appropriate increase of inlet velocity, decrease of annular gap width, and increase of the height in the preliminary separation zone can effectively promote the collision and coalescence process of oil droplets. However, the overlarge height of the preliminary separation zone and the too narrow width of the annular space will both have a significant negative effect on the migration and separation of oil and water and lead to the decrease of separation efficiency.     

板翅式换热器封条质量对瞬变法配比的影响及其修正

当换热面试件中带有封条或其他必须考虑横向导热效应的材料时,这部分材料的质量是否要计入换热面介质的质量,计入多少,将对现有的瞬变传热试验配比结果产生较显著的影响。本文求得了封条质量修正系数的近似分析解,并给出了修正系数图,可以准确、方便地得到参与换热、需要计入换热面质量的那部分封条质量的份额。对封条质量影响进行实验研究的结果表明,这一封条质量修正的计算方法是可靠的。     

算子代数上同调论进展

本文系统地总结了算子代数上同调理论的产生和发展过程。全面地介绍了已见到的各种算子代数上同调理论及其相互关系。并阐述了这个理论在导子的提升,一般的提升,扩张问题,摄动理论和量子力学半群等方面的最新结果。最后,还提出了有待研究、解决的十个问题。     

二阶卷积的构造

文中给出了二阶卷积算子的定义和性质并举例说明。     

“混用体系”中型砌块墙片有限元弹塑性分析

本文采用有限元法对伪静力试验所做的中型砌块墙片进行弹塑性分析计算，砌体中的灰缝单元采用了接触面单元。对“混用体系”中型砌块墙片中芯柱的作用进行了探讨和研究，并提出了一些设计建议。     

有限次可微象征拟微分算子的 L~p(1

赖绍永 《四川师范大学学报(自然科学版)》1989,(3)

关于用线性正算子与Lagrange插值算子的Boolean和逼近

本文是对文[1]的一个注记,将该文的结果推广到多个插值结点的情形,从而在插值结点附近逼近度可以得到改善。     

两个度量空间中集值映象的不动点定理

本文证明了两个度量空间集值映象的一个不动点定理,另一个关于紧度量空间的类似结果也被证明。