水解酸化+接触氧化法+紫外线消毒处理医院污水

介绍水解酸化 接触氧化法 紫外线消毒工艺处理医院污水的工程设计、施工和运行情况。结果表明:处理系统运行稳定,操作管理简单方便,耐冲击负荷,运转费用低,处理效果好,出水水质优于广东省地方标准《水污染物排放限值》(DB44/26-2001)第二时段一级标准。     

Contact angle measurements of Sn-Ag and Sn-Cu lead-free solders on copper substrates

In this study, the contact angles of four lead-free solders, namely, Sn-3.5Ag, Sn-3.5Ag-4.8Bi, Sn-3.8Ag-0.7Cu, and Sn-0.7Cu (wt.%), were measured on copper substrates at different temperatures. Measurements were performed using the sessile-drop method. Contact angles ranging from 30° to 40° after wetting under vacuum with no fluxes and between 10° and 30° with rosin mildly activated (RMA) and rosin activated (RA) fluxes were obtained. The Sn-3.5Ag-4.8Bi exhibited the lowest contact angles, indicating improved wettability with the addition of bismuth. For all soldering alloys, lower contact angles were observed using RMA flux. Intermetallics formed at the solder/Cu interface were identified as Cu₆Sn₅ adjacent to the solder and Cu₃Sn adjacent to the copper substrate. The Cu₃Sn intermetallic phase was generally not observed when RMA flux was used. The effect of temperature on contact angle was dependent on the type of flux used.     

直接接触式冰蓄冷系统双相变过程理论研究

基于一个考虑其晃动后结冰汽泡的物理模型分析了在连续相中结冰汽泡的生长及传热问题，推导了直接接触式冰蓄冷系统蓄冷罐内的容积换热系数，由此得到了一些重要的结论。     

坝体变位和内水压力对坝后背管结构应力的影响

用三维接触单元模拟背管与坝体接触面，分析坝体变形和内水压力对李家峡坝后背管结构应力的影响。坝体变位对背管结构轴向应力的影响表现为上部为拉应力下部为压应力，并且拉应力由背管的上弯段向下弯段逐渐减小，部分轴向拉应力值大于混凝土设计抗拉强度；背管内水压力对背管结构环向应力的影响表现为环向拉应力，并且管腰外缘和管顶内缘混凝土环向拉应力是混凝土设计抗拉强度的2．4倍。根据应力的大小分布可以确定，坝体变形是背管产生较大轴向拉应力的主要因素，是产生环向拉应力的次要因素；内水压力是使背管产生较大环向拉应力的主要因素，是产生轴向拉应力的次要因素。     

A contour integral method to compute the generalized stress intensity factor in complete contacts under sliding conditions

In complete contact fretting problems under global sliding conditions, the stress state at the corner of the contact zone is usually singular (assuming elastic behaviour). This stress state is characterized by two parameters: the order of singularity and the generalized stress intensity factor (GSIF). The former can be analytically calculated for a given problem. However, the GSIF is usually obtained by means of numerical procedures. One of the most used is the application of the stress extrapolation technique in combination with a FE analysis. In this work, a path-independent contour integral is defined which enables the GSIF calculation. Using this novel technique, a much more accurate estimation of the GSIF is obtained for a given discretization. In addition, a refined mesh around the singular point is not needed, because the contour integral can be applied along paths far from the singularity dominated zone due to its path independence.     

混凝沉淀-生物接触氧化法处理染整废水

介绍了采用混凝沉淀-生物接触氧化工艺处理染整废水。运转结果表明：CODCr及BOD5的去除率分别达到94．7％和97．1％，最终出水水质达到国家污水一级排放标准，该工艺在染整废水处理中具有实用性。     

Orientation Phenomena at Polyurethane Surfaces

The surface energies of soft-segment polyurethanes (SPU) have been evaluated by contact angle measurements. These showed that when solidified in air, the surface energies of the polymers were due almost entirely to dispersion forces. When immersed in liquids including formamide, water and saline solutions, surface rearrangements took place, gradually elevating the non-dispersive surface energy component. Equilibrium values varied with the corresponding non-dispersive surface energy of the contacting liquid. XPS analyses confirmed that compositional variations were responsible for changes in the surface energy. The surface restructuring was shown to affect the bond strengths of SPU/adhesive tape joints. The observations are relevant to property control in this important group of macromolecules.     

Microwave preheating of anisotropic conductive adhesive films for high-speed flip chip on flex bonding

Anisotropic conductive adhesive film (ACF) can be preheated by microwave (MW) radiation in order to reduce the bonding time for flip-chip technology. Due to sluggish and nonuniform curing kinetics at the beginning of the curing reaction, thermal curing of epoxy is more time consuming. Therefore, MW radiation may be more effective, due to its uniform heating rate during the cycle. In this paper, MW preheating (for 1–4 sec) of ACF prior to final bonding has been applied to determine the electrical and mechanical performance of the bond. Powers of 80 and 240 W MW were used to study the effect of the MW preheating. A final bonding time of 6–7 sec can be used for flip chip on flex bonding instead of 10–15 sec (standard time for flip chip bonding) for MW preheating time and power used in this study. The contact resistance (as low as 0.01) is low in these samples, whereas the standard resistance is 0.017 ohm (bonded at 180°C for 10 sec without prior MW preheating). The shear forces at breakage were satisfactory (0.167–0.183 KN) for the samples bonded for 6–7 sec with MW preheating. This is very close and even higher than the standard sample (0.173 KN). For MW preheating power of 80 W and sweeping time of 2 sec, final bonding at 6 sec can also be used because of its low contact resistance (0.019 ohm). Scanning electron microscope (SEM) investigation of microjoints and fracture surface shows uneven distribution of conductive particles and thick bond lines in samples bonded for 5 sec (with MW preheating). Samples treated with MW radiation (80 W and 2–3 sec time) serve as evidence that well-distributed particles along with thin bond lines cause low contact resistance and high joint strength.     

半导体器件欧姆接触中的扩散阻挡层

为提高半导体器件欧姆接触的可靠性，一般要在金属化系统中加扩散阻挡层。本文介绍了扩散阻挡层的种类及其特性，并进行了比较和讨论。最后给出了在实际成功应用的例子。