WCDMA容灾备份方案研究

容灾是指当意外灾难发生时系统的应对和恢复能力。本文简要介绍了容灾的定义和等级,详细阐述了核心网部分、智能网部分和彩铃部分的各种容灾备份方案,对于WCDMA网络的建设具有指导意义。     

融合SGSN/MME Pool组网方案探讨

Pool是移动核心网的关键技术之一,也是提升网络安全的重要手段。本文从SGSN/MME Pool的基本原理入手,着重对融合SGSN/MME Pool组网中的关键问题进行了分析,并给出了相应的部署建议。     

LTE核心网MME Pool技术及组网规划研究

结合LTE核心网的技术现状以及发展趋势,介绍了MME Pool的发展背景与核心技术;在对MME Pool和SGSN Pool技术比较的基础上,阐述了MME/SGSN融合Pool的组网优势及技术要点,并对其组网规划进行了建议。     

Pool boiling heat transfer of ultra-light copper foam with open cells

High speed visualizations and thermal performance studies of pool boiling heat transfer on copper foam covers were performed at atmospheric pressure, with the heating surface area of 12.0 mm by 12.0 mm, using acetone as the working fluid. The foam covers have ppi (pores per inch) from 30 to 90, cover thickness from 2.0 to 5.0 mm, and porosity of 0.88 and 0.95. The surface superheats are from −20 to 190 K, and the heat fluxes reach 140 W/cm². The 30 and 60 ppi foam covers show the periodic single bubble generation and departure pattern at low surface superheats. With continuous increases in surface superheats, they show the periodic bubble coalescence and/or re-coalescence pattern. Cage bubbles were observed to be those with liquid filled inside and vented to the pool liquid. For the 90 ppi foam covers, the bubble coalescence takes place at low surface superheats. At moderate or large surface superheats, vapor fragments continuously escape to the pool liquid.     

多元混合物池内核态沸腾换热关联式研究进展

主要针对三元混合物的池内核态沸腾换热实验及关联式拟合进行了总结.在使用统一的方程(α/αid=1/(1 k))的情况下,将众多研究者提出的对关联式中两个主要元素(理想传热系数αid及影响因子k)的计算方程进行了详细比较.分析了现有关联式的不足,并探讨了多元混合物沸腾换热关联式发展的新动向.     

Microfluidic pool structure for cell docking and rapid mixing

A microfluidic pool structure for cell docking and rapid mixing is described. The pool structure is defined as a microchamber on one structural layer of a bilayer chip and connects with two or more individual microchannels on the other structural layer. In contrast to the turbulent flow in a macroscale pool, laminar streams enter and exit this microfluidic pool structure with definite and controllable direction that may be influenced by the location and geometry of the pool. A simple microfluidic model was used to validate this hypothesis. In this model, a microscale pool structure was made on the lower layer of a chip and connected with three parallel microchannels in the upper layer. Simulation and experimental results indicated that the flow profile within the pool structure was determined by its geometry and location. This could be used as a flow control method and it was simpler than designs based on microvalve, hydraulic pressure, or electrokinetic force, and has some important applications. For example, controllable streams within this structure were used to immobilize biological cells along the microchannel walls. When different solution streams flowed through the pool, rapid diffusion of analytes occurred for short diffusion distance between vertical flow laminas. Furthermore, desired dilution (mixing) ratio could be obtained by controlling the geometry of the microfluidic pool.     

A colorimetric assay for the determination of polyhexamethylene biguanide in pool and spa water using nickel-nioxime

A novel nickel-nioxime analytical method to measure polyhexamethylene biguanide (PHMB) in swimming pools and spas was developed. This method utilizes nickel(II) chloride and 1,2-cyclohexanedionedioxime (nioxime) chemistry. In the method, nickel ions bind and neutralize PHMB in the solution. Excess, un-reacted nickel ions react with nioxime and the resulting colored solution is measured at 550 nm using a colorimetric assay. Currently, the colorimetric method to measure PHMB uses bromophenol blue (BPB). However, high levels of quaternary ammonium based algaecides and surfactant based products interfere with this colorimetric method. A time-consuming and expensive high-performance liquid chromatographic (HPLC) analysis can be used for samples with high levels of quaternary ammonium based algaecides or surfactants. The proposed nickel-nioxime detection method achieves comparable PHMB results to HPLC in about 5 min and is a very economical and simple method to perform.     

共沸混合工质HFC23/FC116沸腾传热实验研究

实验测量了二元共沸混合工质HFC23/FC116的池核沸腾传热特性。实验测量的加热面为紫铜表面,热流密度范围为50kW/m~2～300kw/m~2。同时实验结果与复叠温区常用制冷剂HFC13和R503的传热性能进行了比较。最后通过对实验数据进行多元回归分析,得到了共沸混合工质传热系数计算关联式,此关联式的计算值与实验值的偏差在±10%以内。