Graph separators: a parameterized view

Graph separation is a well-known tool to make (hard) graph problems accessible to a divide-and-conquer approach. We show how to use graph separator theorems in combination with (linear) problem kernels in order to develop fixed parameter algorithms for many well-known NP-hard (planar) graph problems. We coin the key notion of glueable select&verify graph problems and derive from that a prospective way to easily check whether a planar graph problem will allow for a fixed parameter algorithm of running time for constant c. One of the main contributions of the paper is to exactly compute the base c of the exponential term and its dependence on the various parameters specified by the employed separator theorem and the underlying graph problem. We discuss several strategies to improve on the involved constant c.     

关于并联机组的回油设计

阐明并联机组设计的关键问题——回油，详细介绍回油管路需要的几个部件，以及制冷管路设计安装时需要注意的几个事项。     

少油断路器中空气室及油气分离器对灭弧能力的影响

在10kV电压等级的少油断路器中,由于在开断大电流和小电流时,对空气室的体积有不同的要求,同时选择合理的油气分离器,可以实现良好的冷却作用和分离油气的能力,避免出现喷油的事故.因此要重视少油断路器的空气室及油气分离器对开断能力的影响.     

三维激光人体头部扫描技术的研究

介绍了快速3D激光人体头部扫描的原理及装置，从计算机软件和硬件两方面详细讨论了实现三维快速扫描的关键技术，给出了视频分离器的实现原理图以及数据采集卡的实现框图，最后详细讨论了数据处理的实现算法，完成了系统总体设计．     

循环流化床锅炉安装技术的探讨

循环流化床锅炉作为一种新型的高效、低污染的燃煤锅炉,在国内热电行业中得到广泛使用,然而在实际应用中,其安装技术对锅炉的使用效能有着较大的影响。文章结合75 t/h循环流化床锅炉现场安装经验,讨论了影响流化床、旋风分离器等重要部位的安装要求,详细提出了循环流化床锅炉耐磨材料施工涉及的若干问题,以及该类型锅炉在安装和试运过程中需注意的问题。     

Separator‐Integrated,Reversely Connectable Symmetric Lithium‐Ion Battery

A separator‐integrated, reversely connectable, symmetric lithium‐ion battery is developed based on carbon‐coated Li₃V₂(PO₄)₃ nanoparticles and polyvinylidene fluoride‐treated separators. The Li₃V₂(PO₄)₃ nanoparticles are synthesized via a facile solution route followed by calcination in Ar/H₂ atmosphere. Sucrose solution is used as the carbon source for uniform carbon coating on the Li₃V₂(PO₄)₃ nanoparticles. Both the carbon and the polyvinylidene fluoride treatments substantially improve the cycling life of the symmetric battery by preventing the dissolution and shuttle of the electroactive Li₃V₂(PO₄)₃. The obtained symmetric full cell exhibits a reversible capacity of ≈87 mA h g^–1, good cycling stability, and capacity retention of ≈70% after 70 cycles. In addition, this type of symmetric full cell can be operated in both forward and reverse connection modes, without any influence on the cycling of the battery. Furthermore, a new separator integration approach is demonstrated, which enables the direct deposition of electroactive materials for the battery assembly and does not affect the electrochemical performance. A 10‐tandem‐cell battery assembled without differentiating the electrode polarity exhibits a low thickness of ≈4.8 mm and a high output voltage of 20.8 V.     

Prediction of shunt currents in a bipolar electrolyzer stack by difference calculus

A model for predicting shunt/leakage currents in a bipolar electrolyzer stack with dual electrolyte inlets and significant amount of gases in the outlet ports and manifold is presented. Model includes electrolyte, manifold and membrane separator as resistance components in the electric circuit analog of the stack. Activation overvoltage associated with electrodes is taken as Tafel-like. Current balance and potential balance equations are applied to the stack and difference calculus is employed to reduce the problem to a set of linear difference equations with constant coefficients. The model is validated with published results and the effect of each resistance component and number of cells on leakage currents in the stack is presented. The U.S. Goverment’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.     

带式永磁磁选机选别攀枝花钛铁矿的试验研究

新型带式中强磁场永磁磁选机选别攀枝花钛铁矿的小型试验研究表明：磁尾分级后，经一次选别作业可得TiO2品位15％左右，回收率80％以上，丢弃尾矿产率40％左右的较好指标。该设备具有处理能力大、生产费用低、占地面积小、操作管理方便等优点，是该矿石粗粒级的理想粗选设备。     

对影响HNS型三相分离设备效率因素的探讨

随着油田后期的开发，油田地面采出液含水都有大幅度的提高，为配合油田生产，河南油田设计院研制出了HNS型三相分离设备。本文着重论述了影响HNS型三相分离设备效率的各种因素，并为提高设备的分离效率，提出了相应的建议和措施。指出保证HNS型高效三相分离器长期平稳运行的三个必要条件：①合理使用破乳剂；②设计出完善的分离结构；③创造一个良好的外部环境。     

管式防砂排砂泵在稠油井中的应用

方法应用管式防砂排砂泵，使油井中和油井底部的砂子易被携带到地面。目的解决现场施工中细粉砂卡泵、携砂排液及其柱塞磨损等问题。结果在现场81口稠油井上的应用表明，其施工成功率100％，有效率达95％以上，累积增油1．7×104t，平均延长油井检泵周期1．5倍以上，创直接经济效益3464×104元。结论该泵具有防砂排砂能力，而且柱塞耐磨，密封性能好；操作方便，具有推广应用价值。