Preparation of the Sb-containing purple conversion coating on brass

A new chemical method for preparing a purple conversion coating on brass was developed. The effect of antimonous oxide concentration and temperature on color and corrosion resistance of the conversion coating, and the change of electric potential with time on coating forming process were studied. The optimum technological conditions were 10?g/L antimonous oxide, 20?g/L copper acetate, 200?mL/L hydrochloric acid at 65°C for 3?min. Results of electrochemical and dropping experiments showed that the brass with purple conversion coating presents better corrosion resistance than bare brass. The scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) results showed that the conversion coating mainly comprising copper and antimony was uniform and compact.     

A fast IP lookup scheme for high speed routers

Abstract

One of the key design issues for the next generation of IP routers is the IP lookup mechanism. IP lookup is an important action in a router, that is, to find the next hop for each incoming packet with a longest‐prefix‐match address in the routing table. In this paper, we propose an IP lookup mechanism with the number of memory accesses for an IP lookup being one in the best case and being four in the worst case. The forwarding table needed by our mechanism is small enough to fit in the SRAM. For example, a large routing table with 40000 routing entries can be compacted to a forwarding table of 260KBytes in our scheme.     

Modeling of a membrane reactor system for crude palm oil transesterification. Part II: Transport phenomena

The mechanistic modeling of biodiesel production process in membrane reactor with the consideration of chemical reaction, phase equilibrium, and ultrafiltration is important for the membrane reactor design. In part II of this work, the chemical and phase equilibrium (CPE) model for crude palm oil transesterification reaction in the membrane reactor developed in part I is extended to an integration of CPE with modified Maxwell–Stefan model, which considers multicomponent mass transport phenomena of concentration polarization and intramembrane. A good fit of simulated permeate fluxes and apparent solute rejection to the experimental data shows that the model has a good prediction capability. Reversible fouling was found to be the major fouling and no pore plugging was observed. Simulation results verified that micelles were retained by the membrane at CPO:MEOH molar ratio of 1:24 and catalyst concentration of 0.5 wt %. However, phase inversion happened when catalyst concentration of 0.05 and 0.1 wt % were used. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1981–1996, 2015     

Topology optimization of transient problem with maximum dynamic response constraint using SOAR scheme

Frontiers of Mechanical Engineering - This paper proposes a novel method for the continuum topology optimization of transient vibration problem with maximum dynamic response constraint. An...     

城市人为热及其影响城市热环境的研究综述

建筑群布局与空间几何形态、下垫面物理属性以及人为热排放是影响城市热岛的3大人为因素.近年来,针对城市热岛与影响因素的研究层出不穷.对城市人为热及其影响室外热环境的研究进行梳理是对影响城市热岛的人为因素进行研究的完善和补充.本文从城市人为排热量统计、人为热对城市室外气温的影响2方面展开,对国内外相关研究进展进行综述,对研究对象、人为排热量计算方法和人为排热量对城市热环境影响研究方法3个方面进行总结,并提炼了一些重要结论.本文为该领域接下来相关研究工作的重点提供了线索,即关注人为热排放与城市规划重要指标的关系,探索人为热对城市热环境的影响机理和内在规律,从而提出更全面、更有效改善城市气候的措施.     

设计院网络规划及管理方法探讨

文章以企业网络规划与管理的理论知识为依据,以上海浦东建筑设计研究院有限公司网络现状为基础,详细分析企业网络需求和改造方案,探讨安全管理策略,从而组建一个安全高速有效的企业网络以满足信息交流和业务开展。     

Performance and mechanism of laser transmission joining between glass fiber‐reinforced PA66 and PC

On account of the large compatibility difference between glass fiber‐reinforced Polyamide 66 (GFR‐PA66) and Polycarbonate (PC), it is difficult to weld them directly by laser. A new technology is introduced in this article by which the transparent PC is successfully welded with GFR‐PA66 using cold spraying in order to spray a 20 μm‐thick aluminum film on GFR‐PA66 as the absorbed layer. Tensile shear tests show the tensile strength of welded joints is highly enhanced. The influences of bubbles, glass fiber, and aluminum atoms on the performance of the joins are investigated via the optical microscope. X‐ray Photoelectron Spectrometer (XPS) is used to detect the chemical information of fracture sections on PC. In terms of the generation of bubbles, the influence of glass fiber, the distribution of aluminum atoms, and the formation of new chemical bonds, this article analyses the mechanism why the two different materials can be welded successfully. The micro‐anchor influence of glass giber in fiber‐reinforced polymers is important. The generation of new chemical bonding (Al–O–C) between aluminum and upper PC is the main reason why the joining strength is enhanced greatly. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43068.