轮廓度误差的精密测量和评定

对具有复杂、不规则轮廓的零件进行精密测量和误差评定，是当前几何量计量领域中后个重要课题。本文针对在坐标测量机上进行轮廓测量提出了对曲线和曲面轮廓的数学描述方法、对曲线和曲面的等距平移以得到实测轮廓、以及引入矢量积运算对实际轮廓误差进行法向评定，从而实现了对零件复杂形面的精密测量和误差评定，对国家和国际标准中轮廓度公差标准的贯彻实施可起到推动作用，并最终达到提高产品质量的目的。     

平面复杂曲线轮廓度误差评定和判别

总结了平面曲线轮廓度误差的测量方法和评定准则,提出了平面曲线轮廓度误差最小区域几何判定准则。给出了平面曲线轮廓度误差评定的数学模型及其计算方法,通过对测量曲线特征点的平移、旋转及最大误差方向移动完成粗配准,进而用坐标轮换法按最小条件原则实现平面曲线的精匹配以消除测量时的定位误差。最后通过实例证明几何准则的正确性和计算方法的可行性。     

探讨计算标准曲线方程的一种新方法——斜率平均法

本文力求探索一种求标准曲线方程的新的计算方法，通过计算标准的斜率，相加后平均即为所求标准曲线方程的斜率，首先从数学上进行了证明，又列举了计算实例，并与回归方程法作了比较，通过探讨，寻求一个简便，易行，准确地计算标准曲线方程的新方法。     

叉杆送接传动机构凸轮曲线的推导与计算机辅助设计

叉杆送接传动机构凸轮曲线的精确度,直接影响印刷机印刷速度的提高。通过叉杆送接传动机构的传动原理与运动分析,确定其约束参数和约束条件。推导出送、接凸轮轮廓曲线方程,并应用C语言程序设计,采用中间比例插入数值法,计算和绘制送、接凸轮轮廓曲线,提高了凸轮轮廓曲线的精确度,为凸轮轮廓曲线的加工,提供了依据。     

轮廓支承长度率的简便测量与评定

本文介绍了用触针式轮廓仪或光切显像镜，通过做轮廓图形幅度分布曲线和轮廓支承长度率曲线，解决了不具备多功能参数轮廓仪也可测量，评定轮廓支承长度率值问题。     

轮廓支承长度率的简便测量与评定

本文介绍了用触针式轮廓仪或光切显微镜，通过做轮廓图形幅度分布曲线和轮廓支承长度率曲线，解决了不具备多功能参数轮廓仪也可测量、评定轮廓支承长度率值问题。     

表面粗糙度的表征参数分析

1引言在现行国标和国际标准中规定的粗糙度参数大致可分为三类，第一类：与高度特性有关的参数，如轮廓算术平均偏差Ra、轮廓均方根偏差Rq、微观不平度十点高度Rz和轮廓最大高度Ry，等；第二类：与间距特性有关的参数，如轮廓的均方根波长λq、轮廓微观不平度的平均间距Sm、轮廓的单峰平均间距S等；第三类：与形状特性有关的参数，如幅度分布、轮廓的偏斜度Sk、轮廓的均方根斜率b。、轮廓的支承长度率曲线等。在国标和各种参考书中都作了详细的叙述，本文则从统计的角度介绍几个在研究领域应用较多的参数．及它们之间的相互关系。2平均粗…     

高聚物的DSC相变曲线的模拟

研究了从ＤＳＣ相变曲线计算相变转化率和转化率对时间的一阶导数的二阶导数的样条函数方法。结果表明，用样条函数模拟ＤＳＣ相变曲线可适用于各种高聚物及多重相变峰，并具有较高的精度．     

表面统计粗糙度理论与评定方法

本文对表面粗糙度研究的现状和存在的问题进行了分析,提出了表面统计粗糙度SSR的新概念,给出了它的评定参数和相应的评定方法。由SSR的基本评定参数FEP(表面轮廓模型参数α)可确定任何一种评定参数及其关系。本文还建立了表面轮廓和分离表面轮廓测量干扰及仪器误差的数学模型。通过一系列的试验和计算机上的计算,证明本文所提出的理论和方法是正确的。     

极径曲线生成及其在产品设计中的应用

将定义在极坐标系中的极径曲线转换到( ρ, θ) 直角坐标系中进行设计、控制, 研究了用传统的曲线造型方法实现对具有特定要求的零件轮廓曲线的设计、造型方法。作为应用, 还给出了几个零件轮廓曲线设计实例。     

Intensity profiles along the RHEED streaks for various thin film surface morphologies

Intensity distribution profiles of reflection high energy electron diffraction (RHEED) along the (00) and (01) reciprocal rods are calculated as a function of the grain width, the height difference between neighbouring grains (intergrain roughness), and the surface roughness of the individual grain (intragrain roughness). The calculations include the refraction and the absorption of electron beams and the shadowing effect by the neighbouring grains. The calculations show that the major intensity moves from the three-dimensional (3D) Bragg diffraction to the specular beam as the grain width increases and that a remarkable change in the intensity profiles occurs when the grain width becomes comparable with the decay length of the electron beam in the film. Not only the growth of 3D Bragg peaks but also shifts of the peak positions, induced by the increase of the intra- and intergrain roughness, are simulated. The calculated spectra are compared with the experimental intensity profiles along the streaks measured together with a RHEED intensity oscillation during a homoepitaxy of Ag films.     

地表粗糙度对山区峡谷地形桥址区风场影响研究

为研究地表粗糙度对山区峡谷地形桥址区风环境的影响,通过计算流体力学数值模拟的方法,对不同粗糙度下理想峡谷与真实峡谷模型中主梁跨中位置的风剖面进行了研究。通过理想模型的计算分析,确定了不同风向角下主梁跨中风剖面随粗糙度变化的一般规律,结合对峡谷内流场特点的分析,揭示了粗糙度对峡谷内风速造成影响的原因,并在真实地形模型中进行了验证,根据地表种类细化了粗糙度设置方案。研究表明,在峡谷地形条件下,粗糙度对风速的影响与常规地形有明显差异,在主梁高度处,随着粗糙度的增加,主梁跨中风速可能会有不同程度的增加。研究结论为山区峡谷地形处桥梁设计风速确定提供了依据。     

Experimental Investigation of Thermal Contact Conductance: Variations of Surface Microhardness and Roughness

Surface roughness parameters were measured using nine different sampling intervals. The results showed that the roughness of profile was nearly a constant at all sampling intervals; the slope, peak curvature and density of the profile decreased with increasing sampling interval; and the distribution of the peak height was different from the profile height distribution and was not Gaussian. It was found that the surface microhardness value, under small loads, varied with the indentation size and the surface preparation procedure. A model was developed which used a discretization method to obtain the contact radius and area in each section of the surface summit height distribution curve. This model eliminated some of the assumptions made by previous models and can be used to predict the thermal contact conductance without assuming the asperity deformation mode and surface summit height distribution. The predicted thermal contact conductance values were in good agreement with experimental results.     

用轮廓离散法研究粗糙表面间的接触导热

通过ＳＴＡＲ－１型表面轮廓仪对粗糙表面实际形貌的测定,分析得到了实际表面微凸体的高度分布和曲率分布,发现微凸体的高度分布并非高斯,而曲率分布则呈随机状态,运用轮廓离散的广泛和显微硬度的概念,得到了各高度下微凸体的数量和实际形变,建立了粗糙表面接触热导的离散化模型,该模型消降了常规模型中有关微凸体高度分布和形变类型的人为假设。模型与实验数据吻合程度良好,其预测精度比Ｇ－Ｗ模型和Ｙ模型高。     

Introduction and application of modified surface roughness parameters based on the topographical distributions of peaks and valleys

A set of modified roughness parameters (N%‐Rpv's) is introduced based upon the separate distribution of peaks and valleys. These new measures of surface roughness are utilized to quantitatively evaluate the as‐rolled and deformation‐induced surface roughness of Al sheets. N%‐Rpv is defined as the difference between the average heights of the upper N% of peaks and the lower N% of valleys. As N decreases, the magnitude of N%‐Rpv tends to be more sensitive to the contribution from relatively large‐wavelength roughness components. The topographical difference between the transverse direction (TD) and the rolling direction (RD) roughness profiles of the as‐rolled surface is shown to be characterized more realistically by N%‐Rpv than the root‐mean‐square roughness (Rq). The result from this quantification of deformation‐induced surface roughness of the Al sheet at intermediate and macroscopic scales suggests that the presence of spatially organized macro‐roughening patterns can be characterized using the relative magnitudes of 100%‐Rpv and 10%‐Rpv. This suggests a possible link between the spatial distribution of surface roughness and the magnitude of N%‐Rpv.     

Discrepancies between roughness measurements obtained with phase-shifting and white-light interferometry

Discrepancies between phase-shifting and white-light interferometry have been observed in step-height and surface roughness measurements. The discrepancies have a strong relation to the roughness average parameter of the surface. The skewing effect, which mainly occurs in the vicinity of peaks, valleys, and edges of the sample, causes this problem in white-light interferometry of step height. For roughness, two possible sources of the discrepancy are considered.     

树枝状介孔氧化硅磨粒的制备和抛光性能

使用油水双相分层反应体系(以萘烷为上层油相)制备了具有Y型孔道的树枝状介孔氧化硅颗粒(DMSPs)。透射电镜、扫描电镜、X射线衍射、氮气吸附/脱附和粒度分布的测试结果表明:所得DMSPs样品的粒径为72±6 nm,在液相环境中粒度的分布较窄;其内部的三维中心辐射状介孔孔径为6~8 nm,但是孔道结构没有长程有序性。氧化硅片经DMSPs磨粒抛光后表面的粗糙度均方根值由0.76下降至0.21 nm,最大轮廓波峰高度由1.48下降至0.50 nm、最大波谷深度则由1.86下降至0.45 nm,材料去除率高达187 nm/min。讨论了DMSPs磨粒在界面摩擦磨损和接触粘附过程中的作用机制。     

The influence of surface diffusion on surface roughness and component distribution profiles during deposition of multilayers

The kinetic processes taking place on the surface and influencing the depth distribution of components during deposition of multilayers are considered by proposed kinetic model. The depth distribution of components in growing structure, broadening of interfaces between layers and shape of concentration peaks of multilayers are analyzed with respect of evolution of surface roughness during deposition. Surface roughness depends on adsorption rate and on surface diffusion. In presented model, the process of surface diffusion is subdivided into up-diffusion and down-diffusion. It is shown that atomic fluxes of up-diffusion and down-diffusion do not compensate each other even in the case of equal diffusion coefficients as they depend on coverage of different monolayers. Down-diffusion results in smoother surface, in contrary, up-diffusion makes it rougher. It is quantitatively shown by kinetic modeling that with increase of down-diffusion the amplitude of concentration peaks of components increases, the broadening of interface between layers decreases and concentration peaks become asymmetrical. The asymmetry of concentration peaks is found even in the case of equal diffusion coefficients of different components. At different diffusivity of components, the asymmetry is following: the concentration peaks of heavy-component (less diffusivity) show enhanced trailing tails on the back profile side (for light-component on the contrary). Up-diffusion results in increase of surface roughness and broadening of interface between layers. The quantitative functions of surface roughness on ratio of up- and down- diffusion coefficients are calculated and analyzed.     

Influence of fluorinated self-assembled monolayer on wetting dynamics during evaporation of refrigerant–oil mixture on metal surface

Reducing wettability of a metal surface is a promising method for enhancing boiling heat transfer of refrigerant–oil mixture on the metal. As fluorinated self-assembled monolayer (F-SAM) coating is effective for wettability reduction, its influence on wetting dynamics including meniscus shape, contact angle, contact line velocity and rising liquid height during evaporation of refrigerant–oil mixture on metal surface were experimentally investigated. The refrigerant–oil mixture was prepared by R141b and NM56, the oil mass fraction ranged from 0 to 10 wt%, and the surface roughness ranged from 0.028 to 1.166 µm. The results show that during evaporation of refrigerant–oil mixture, the presence of F-SAM changes the evaporation mode to be constant contact line velocity followed by both constant contact angle and contact line velocity, while decreases the rising liquid height. The results suggest that larger surface roughness and higher oil mass fraction are preferred when using F-SAM to reduce surface wettability.