不良导体热系数和热体散热率测量方法研究(英文)

本文介绍一种直接测量散热率新方法．进而测出不良导体的热系数。该方法，减小了由间接测量散热率所带来的误差，实验装置简单，操作方便，参数少，测量结果的精确性和重复性都有较大提高，更重要的是这一新的实验方法突出了物理思想。     

Noise-assisted mound coarsening in epitaxial growth

Two types of mechanisms are proposed for mound coarsening during unstable epitaxial growth: stochastic, due to deposition noise, and deterministic, due to mass currents driven by surface energy differences. Both yield the relation H=(RWL)² between the typical mound height W, mound size L, and the film thickness H. An analysis of simulations and experimental data shows that the parameter R saturates to a value which discriminates sharply between stochastic () and deterministic () coarsening. We derive a scaling relation between the coarsening exponent 1/z and the mound-height exponent which, for a saturated mound slope, yields . Received: 11 November 1997 / Revised in final form: 28 November 1997 / Accepted: 28 November 1997     

金刚石薄膜的制备及其性能研究概述

金刚石薄膜是工业界继高温超导材料之后的又一研究热点，近年来的研究工作已经取得了重大进展。文章对国内外学者在金刚石薄膜的制备、特性、生长机理以及摩擦特性等方面的研究进行了综合论述，以推动国内外金刚石薄膜基础研究和应用的发展，并提出要重视金刚石薄膜在摩擦学领域中的应用研究，使之为人类社会带来巨大的经济效益。     

氯离子对碳钢在混凝土孔隙液中腐蚀行为的影响

采用重量法、线性伏安扫描法、弱极化法和SEM,研究C l-对碳钢在模拟混凝土孔隙液(饱和Ca(OH)2溶液)中的腐蚀行为的影响.结果表明,高pH值的混凝土孔隙液能减缓氯离子对碳钢的腐蚀;当pH≥13.6时,在NaC l浓度小于3%的混凝土孔隙液中,碳钢表面因生成钝化膜而不被腐蚀;当pH≤9时,混凝土孔隙液中无论是否存在C l-,碳钢均会被腐蚀;当pH=12.5时,混凝土孔隙液中NaC l浓度小于0.05%,碳钢则不被腐蚀;当混凝土孔隙液中的C l-浓度达到临界氯离子浓度时,碳钢表面的钝化膜开始损坏而被腐蚀,碳钢的腐蚀速度随着C l-浓度的增加而增大.     

BRD96N光调制吸收增强现象的实验研究

通过光谱响应特性实验和记录／读出图像实验，研究了基因变异型细菌视紫红质（BR_D96N）分子膜对单色光的光调制特性.发现BR_D96N分子膜在550nm—600nm范围内对调制光有吸收增强的现象，且对此范围内不同波长的单色光其调制程度有差异.利用曲线拟和方法发现550nm—600nm吸收增强的变化过程分为快过程和慢过程，其对应的时间常数分别为30s和5min.利用强度调制器的吸收强度与图像灰度之间的关系，分析了560nm—600nm范围内出现图像反转的实验现象. 关键词： 细菌视紫红质D96N分子膜 光谱响应 吸收增强现象 图像反转现象     

Dynamic response of permalloy/Cu/Co magnetoresistive sandwiches

The dynamic response of trilayer magnetoresistive permalloy/Cu/Co films was studied by high-frequency permeability spectra measurements. The resonance frequency is shown to depend on the interlayer copper thickness. This dependence is related to exchange coupling between permalloy and cobalt and the interaction field is estimated using the Landau–Lifschitz–Gilbert model.     

非晶硅薄膜的低温快速晶化及其结构分析

在镀铝的廉价玻璃衬底上高速沉积的非晶硅薄膜在不同的温度下退火10min.退火温度为500℃时,薄膜表面形成了硅铝的混合相,非晶硅薄膜开始呈现了晶化现象 退火温度为550℃时,大部分(约80%)的非晶硅晶化为多晶硅,平均晶粒尺寸为500nm 退火温度为600℃时,几乎所有的非晶硅都转化为多晶硅,其平均晶粒尺寸约为15μm.     

过氧聚钨酸薄膜上光栅的制备

用过氧聚钨酸（PPTA）水溶液，通过离心涂膜法在显微镜载玻片上制备了具有光滑表面且厚度为100nm的PPTA薄膜，利用PPTA薄膜在紫外光照下可研制光栅以及其它光学元件的薄膜材料，具有很高的利用价值。     

Temperature effect on deposition rate of silicon nitride films

Temperature effects on deposition rate of silicon nitride films were characterized by building a neural network prediction model. The silicon nitride films were deposited by using a plasma enhanced chemical vapor deposition system and process parameter effects were systematically characterized by 2⁶⁻¹ fractional factorial experiment. The process parameters involved include a radio frequency power, pressure, temperature, SiH₄, N₂, and NH₃ flow rates. The prediction performance of generalized regression neural network was drastically improved by optimizing multi-valued training factors using a genetic algorithm. Several 3D plots were generated to investigate parameter effects at various temperatures. Predicted variations were experimentally validated. The temperature effect on the deposition rate was a complex function of parameters but N₂ flow rate. Larger decreases in the deposition rate with the temperature were only noticed at lower SiH₄ (or higher NH₃) flow rates. Typical effects of SiH₄ or NH₃ flow rate were only observed at higher or lower temperatures. A comparison with the refractive index model facilitated a selective choice of either SiH₄ or NH₃ for process optimization.     

Curved Ferroelectric Liquid Crystal Matrix Displays Driven by Field-Sequential-Color and Active-Matrix Techniques

This paper describes a curved field-sequential-color matrix display using fast-response ferroelectric liquid crystal. Black matrix and transparent electrode patterns were formed on a thin plastic substrate by a transfer method from a glass substrate. While a composite film of liquid crystal and micro-polymers of walls and fibers was formed between the flexible substrates by printing, laminating and curing processes of a solution of monomers and liquid crystal, the mechanical stability was enhanced by use of multi-functional monomers to form large display panels. The image pixels of the matrix panel were driven by an active matrix scheme using an external switch transistor array at a frequency of 180 Hz for intermittent three-primary-color backlight illumination. The flexible A4-paper-sized color display with 24 × 16 pixels and 60 Hz field frequency was demonstrated by illuminating it with sequential three-primary-color lights from light-emitting diodes of the backlight. Our display system is useful in various information displays because of its freedom of setting and location.