INTERFACE/INTERPHASE ENGINEERING OF POLYMERS FOR ADHESION ENHANCEMENT: PART II. THEORETICAL AND TECHNOLOGICAL ASPECTS OF SURFACE-ENGINEERED INTERPHASE-INTERFACE SYSTEMS FOR ADHESION ENHANCEMENT

Part I of this paper reviewed the theoretical principles of the macromolecular design of polymer interface/interphase systems for obtaining maximum adhesion and fracture performance of adhesively bonded assemblies. In Part II a novel, relatively simple and industry-feasible technology for surface-grafting connector molecules is demonstrated and discussed in detail and supported by a range of experimental examples. It is shown, in agreement with contemporary theory, that the use of chemically attached graft chemicals of controlled spatial geometry and chemical functionality enables a significant increase in the strength and fracture energy of the interphase, to the point of cohesive fracture of the substrate, or that of an adjacent medium such as adhesive, elastomer, or other material. This occurs even after prolonged exposure of investigated systems to adverse environments such as hot water.     

在p+GaAs体单晶材料上进行的NEA活化实验

NEA活化实验是利用体单晶材料进行的,未经任何外延或真空解理手续。为确立活化工艺,特别是表面清洁处理规范,作了相应AES分析。借助于测量样品附近高纯Al的熔点以校准及控制样品表面的温度。在不太好的本底真空(2×10^-7—6×10^-7Pa)条件下,活化好的GaAs样品之白光光电灵敏度可达1000μA/lm以上。     

Experimental investigation of natural convection from a horizontal ice surface melting in pure water

A study on natural convection from a horizontal ice surface melting in pure water was conducted experimentally for the ambient water temperature from 2▿C to 10°C. Natural convection flow around upward-or downward-facing horizontal ice plate was divided into three regions according to the temperature variation of ambient water. The flow patterns of three regions were no flow, two-dimensional steady laminar flow and unsteady flow. Mean Nusselt number for the upward-facing surface had its maximum value at about 3°C of ambient water temperature. However, in the case of the downward-facing surface it increased as the ambient water temperature increased.     

近程地对地战术导弹的作用与问题

海湾战争中,“爱国者”导弹成功地拦截了“飞毛腿”导弹,给近程地对地战术导弹的作用、发展与装备方向提出了值得思考的问题。本文着重讨论在局部战争中,近程地对地战术导弹的作用、使用场合及其技术发展方向。     

The catalytic activity and surface characterization of Ln2B2O7 (Ln=Sm, Eu, Gd and Tb; B=Ti or Zr) with pyrochlore structure as novel CH4 combustion catalyst

Ln₂B₂O₇ (Ln=Sm, Eu, Gd and Tb; B=Zr or Ti) with pyrochlore structure was prepared by sol–gel method for the high-temperature catalytic combustion. The crystal structure of Ln₂B₂O₇ was identified by XRD and their surface area was about 4 m²/g after calcinations at 1200 °C. Catalytic activity of methane combustion was observed for Ln₂Zr₂O₇ series and the best catalyst was Sm₂Zr₂O₇. Its relative reaction rate per unit surface area at 600 °C was 2 cm³/m² min, which was twice higher than that of Mn-substituted Sr hexaaluminate. From surface analysis by XPS, the low binding energy of each Ln element of Ln₂Zr₂O₇ compared to that of Ln₂Ti₂O₇, gave the catalytic activity of methane combustion.     

精密铜带圆盘纵剪机

通过对精密铜带圆盘剪切机的工作原理和工艺过程进行研究，对引进的美国剪切机进行了技术改造，设计制作了新的装置，实现了软态铜带的剪切。     

Very low surface recombination velocities on p-type silicon wafers passivated with a dielectric with fixed negative charge

Surface recombination velocities as low as 10 cm/s have been obtained by treated atomic layer deposition (ALD) of Al₂O₃ layers on p-type CZ silicon wafers. Low surface recombination is achieved by means of field induced surface passivation due to a high density of negative charges stored at the interface. In comparison to a diffused back surface field, an external field source allows for higher band bending, that is, a better performance. While this process yields state of the art results, it is not suited for large-scale production. Preliminary results on an industrially viable, alternative process based on a pseudo-binary system containing Al₂O₃ are presented, too. With this process, surface recombination velocities of 500–1000 cm/s have been attained on mc-Si wafers.     

精铸型壳"墨点"和铸件"黑皮"分析

以锆石砂粉为面层、高岭石系耐火材料为背层制成的精铸型壳浇注不锈钢铸件．经常在铸件表面出现大面积“黑皮”和相互孤立的凹陷疤痕，严重影响铸件质量．通过生产现场跟踪调查．结合俄歇能谱分析等手段．对缺陷部位化学组成和形成原因进行分析探讨．指出：铸件表面的疤痕与型壳表面“墨点”直接相关；而“黑皮”主要是硬壳面层中的氧化铁与铸件表面氧化产生的各种金属氧化物反应生成的尖晶石型复杂化合物。在此基础上，提出了防止此类缺陷的措施。     

A new curvature technique calculation for surface tension contribution in PLIC-VOF method

The volume of fluid (VOF) methods have been used for numerous numerical simulations. Among these techniques used to define the moving interface, the piecewise linear interface reconstruction (PLIC-VOF) is one of the most accurate. A study of the superficial tension impact on two-phase flow with free surface is presented. A new method based on direct staggered grid is developped to include surface tension in PLIC-VOF. The new numerical curvature calculation method doesn't need smoothed colour function and leads to less “spurious current”. This technique is applied to the calculus of surface tension force in the case of the rise of air bubble in viscous liquid and the fall of liquid drop in the same liquid on free surface. Droplets, thin layer and capillarity waves are observed after the free surface rupture for different Bond number. The influence of surface tension calculus is then obvioused and when the drop hit the free surface, wavelets propagate toward the virtual boundaries imposed.     

高速硬车削淬火钢的实验研究

通过改变高速车削淬火钢（Cr12）的切削用量，对切削力、切削温度、加工表面质量等进行了研究，结果表明合理选择切削用量，高速硬车削淬火钢可显著提高生产率及加工表面质量，并在一定程度上可取代磨削加工。