磁控溅射薄膜生长全过程的计算机模拟研究

本文通过建立多尺度模型,结合模拟了磁控溅射中溅射原子的产生、溅射原子的碰撞传输、以及最终成膜的全过程,研究了基板温度、溅射速率、磁场分布和靶材-基板间距对薄膜生长过程与薄膜性能的影响.模拟结果显示,提高基板温度或降低溅射速率都会增加初期生长阶段薄膜的相对密度;磁场对靶的利用率有显著的影响,而对薄膜最终形貌的影响不大;增大靶材-基板间距会降低薄膜的粗糙度.     

磁控共溅射Al-Cu-Fe薄膜表面形貌分析

利用磁控共溅射方法采用不同的溅射工艺在单晶硅基片沉积制备了Al-Cu-Fe薄膜.运用原子力显微镜镜(AFM)分析了Al-Cu-Fe薄膜的表面形貌、表面粗糙度和晶粒尺寸.结果表明:随着溅射气压的减小,薄膜表面粗糙度和晶粒尺寸均有所减小.当基底温度升高至450℃时,Al-Cu-Fe薄膜的粗糙度和晶粒尺寸明显增加.溅射时间的延长导致了薄膜的表面粗糙度下降和晶粒尺寸的长大.增加溅射功率会使薄膜表面粗糙度有所增加.     

磁控共溅射Al-Cu-Fe薄膜表面形貌分析EI

利用磁控共溅射方法采用不同的溅射工艺在单晶硅基片沉积制备了Al-Cu-Fe薄膜.运用原子力显微镜镜(AFM)分析了Al-Cu-Fe薄膜的表面形貌、表面粗糙度和晶粒尺寸.结果表明:随着溅射气压的减小,薄膜表面粗糙度和晶粒尺寸均有所减小.当基底温度升高至450℃时,Al-Cu-Fe薄膜的粗糙度和晶粒尺寸明显增加.溅射时间的延长导致了薄膜的表面粗糙度下降和晶粒尺寸的长大.增加溅射功率会使薄膜表面粗糙度有所增加.     

铝合金功能薄膜与溅射靶材

近年来 ,铝合金广泛用于生产多种功能薄膜。作为制备高性能溅射薄膜用的铝合金靶材也得到了相应的应用。本文重点介绍应用于不同领域的几种铝合金功能薄膜 ,简述了铝合金薄膜与溅射靶材的制备工艺、铝合金靶材的显微结构及其对溅射薄膜性能的影响 ,最后指出了铝合金薄膜及溅射靶材的发展趋势     

铝合金功能薄膜与溅射靶材

近年来,铝合金广泛用于生产多种功能薄膜,作为制备高性能溅射薄膜用的铝合金靶材也得到了相应的应用。本重点介绍应用于不同领域的几种铝合金功能薄膜,简述了铝合金薄膜与溅射靶材的制备工艺、铝合金靶材的显微结构及其对溅射薄膜性能的影响,最后指出了铝合金薄膜及溅射靶材的发展趋势。     

磁控溅射参数对Al薄膜微观结构及红外特性的影响研究

利用磁控溅射法在Si(100)基片上制备了Al薄膜,采用X射线衍射、扫描电镜、扫描探针显微镜和红外光谱仪研究了基片温度、溅射功率和溅射时间对Al薄膜表面、断面形貌和红外反射率的影响。结果表明:随着基片温度的升高,Al颗粒的尺寸变大,由均匀细颗粒变为不规则形状,并逐渐熔为一个整体,断面形貌变得凹凸不平,表面粗糙度增大,红外反射率呈下降的趋势;随着溅射功率的增大,Al薄膜致密平整,表面粗糙度增大,红外反射率先增大后不变;随着溅射时间的延长,Al薄膜表面粗糙度增大,红外反射率先增大后不变。     

离子束技术沉积羟基磷灰石薄膜的结构及溶解性能

分别采用离子束溅射和离子束增强沉积技术,以烧结羟基磷灰石（HA）陶瓷为靶材,在纯钛金属基片表面沉积HA薄膜．X光电子能谱分析表明：薄膜中Ca、P、O元素的化学态与所用HA陶瓷靶材相接近;相比HA靶材,薄膜表面存在CO₃^2-．X射线衍射分析表明：沉积薄膜均为非晶态结构,经650℃退火处理转变为结晶磷灰石．在模拟体液中的溶解实验揭示：薄膜仅与溶液中Ca、P和O存在离子交换;薄膜易降解,浸泡10天,样品经历了降解、再沉积过程;相比离子束溅射沉积膜,离子束增强沉积膜具有加速沉积Ca、P的能力．     

CuNiSi溅射薄膜热性能与溅射靶材中稀土元素加入量之间关系的研究

应用光热辐射和光学速反射的方法了靶材中Ｌａ系混合稀土元素加入量对ＣｕＮｉＳｉ溅射薄膜热性能的影响。靶材中Ｌａ系混合稀土元素的加入引起被溅射薄膜热行为的差异,随着靶材料中Ｌａ系稀土元素加入量的提高,被溅射的ＣｕＮｉＳｉ薄膜的热扩散系数α也增加。     

不同溅射功率下PEN/Ti纳米复合薄膜的制备及性能研究

采用直流磁控溅射法,在溅射气压为7.0×10~(-1) Pa和不同溅射功率(72～144W)下,制备出PEN/Ti纳米复合薄膜。研究了不同溅射功率对Ti膜微观组织、表面粗糙度、硬度及生长方式的影响规律。结果表明,直流磁控溅射法在PEN柔性衬底上沉积的钛膜是一种纳米多晶薄膜;随着溅射功率的增加,钛膜沉积速率及钛膜弹性模量皆升高,而钛膜表面粗糙度与钛膜晶粒尺寸均减小;溅射功率的增加将抑制钛膜柱状生长方式。在溅射气压为7.0×10~(-1) Pa,溅射功率为144 W时的工艺参数下,获得性能最佳的复合薄膜。     

Ti靶及TiO2靶溅射TiO2薄膜微观形貌、结构及光学性质研究

利用射频磁控溅射技术通过Ti靶及TiO2靶在氩氧气氛中同时溅射制备TiO2薄膜,并对所得的样品进行不同温度的退火处理。采用X射线衍射、扫描电子显微镜、拉曼光谱和吸收谱研究了不同的靶材及退火温度对TiO2薄膜晶体结构、微观形貌及光学性质的影响。结果表明:由于靶材的不同,Ti靶溅射时氧分压较低,造成薄膜中存在大量的氧缺陷,晶相发育不完善,颗粒相比TiO2靶溅射时较小,从XRD和拉曼光谱来看,Ti靶溅射得到的TiO2薄膜更有利于金红石相的形成。薄膜的透过率随退火温度的升高而降低,TiO2靶材溅射的薄膜的光学带隙随温度升高而明显降低,而Ti靶得到的薄膜的光学带隙对退火温度的依赖关系不明显。     

凝固科学技术与材料

从凝固科学与实践发展的角度介绍了当前凝固材料体系的基本框架和凝固科学主要发展阶段的基本理论。作为材料科学与工程的基本组成，凝固科学技术正在现代科学理论的基础上针对传统材料的改性提高和新材料的发展需求，以控形、控构、控性为目标开展优质铸件的定向、晶体生长、快凝、深过冷及各种新型和超常领域凝固过程的研究，并介绍了其中某些方面和展望了可能的发展趋势。     

Development and challenges of planning and scheduling for petroleum and petrochemical production

Production planning and scheduling are becoming the core of production management, which support the decision of a petrochemical company. The optimization of production planning and scheduling is attempted by every refinery because it gains additional profit and stabilizes the daily production. The optimization problem considered in industry and academic research is of different levels of realism and complexity, thus increasing the gap. Operation research with mathematical programming is a conventional approach used to address the planning and scheduling problem. Additionally, modeling the processes, objectives, and constraints and developing the optimization algorithms are significant for industry and research. This paper introduces the perspective of production planning and scheduling from the development viewpoint.     

The Candela and Photometric and Radiometric Measurements

The national measurement system for photometric and radiometric quantities is presently based upon techniques that make these quantities traceable to a high-accuracy cryogenic radiometer. The redefinition of the candela in 1979 provided the opportunity for national measurement laboratories to base their photometric measurements on optical detector technology rather than on the emission from high-temperature blackbody optical sources. The ensuing technical developments of the past 20 years, including the significant improvements in cryogenic radiometer performance, have provided the opportunity to place the fundamental maintenance of photometric quantities upon absolute detector based technology as was allowed by the 1979 redefinition. Additionally, the development of improved photodetectors has had a significant impact on the methodology in most of the radiometric measurement areas. This paper will review the status of the NIST implementation of the technical changes mandated by the 1979 redefinition of the candela and its effect upon the maintenance and dissemination of optical radiation measurements.     

江澳两地高校文创设计的协同研究与商业实践

目的 探索江门世遗文化的传承、发展和转化的新思路,践行国家在《粤港澳大湾区发展规划》纲要中要求江门承担与港澳地区文化创意合作与开发任务的分工。方法 与澳门高校紧密合作,开展专业培训课程,以开平碉楼为例,从人文视角开展设计研究,梳理开平碉楼的文化脉络,把世遗文化的元素和其背后的文化融入文创产品中,提升文创产品的附加值,推动当地文创产业结构的变革。结果 两地高校构建了稳定的科研团队,开设长期有效的设计培训课程,与景区建立了研究协作关系,帮助景区构建了一套产销研的商业模式。结论 以跨区域高校合作为平台,以文创产品为抓手,依托江澳两地的资源优势,可以构建江门世遗文化全新的品牌形象,最终推动开平世遗文化的活化。     

PSD和PWELCH函数的分析改进及应用

针对MATLAB中两个内建功率谱密度计算函数psd()和pwelch()计算结果迥异的现象,在功率谱密度估计理论的基础上,根据经典的周期图理论和Welch平均周期图方法,通过详细分析源程序,解析计算方法,发现psd()计算的并不是工程单边功率谱密度,而是采样信号双边谱,故与pwelch()结果迥异,另外pwelch()不能对分段信号数据进行预处理。就上述不足提出了相应的改进措施,比较验证表明改进措施行之有效。     

Creation and motion of dislocations and fracture in metal and silicon crystals

By making a step on one surface ( ) of a rectangular small paralellepiped copper crystal, dislocations could be created by the molecular dynamic method. The dislocation created was not a complete edge dislocation but a pair of Heidenreich-Shockley partial dislocations. Each time a dislocation was created, the stress on the surface was released. Small copper crystals having a notch were pulled (until fracture), compressed and buckled by use of the molecular dynamic method. An embedded atom potential was used to represent the interaction between atoms. Dislocations were created near the tip of the notch. A very sharp yield stress was observed. The results of high speed deformations of pure silicon small crystals using the molecular dynamics are presented. The results suggest that plastic deformation may be possible for the silicon with a high speed deformation even at room temperature. Another small size single crystal, the same size and the same surfaces, was compressed using molecular dynamic method. The surfaces are {110}, {112} and {111}. The compressed direction was [111]. It was found that silicon crystals are possible to be compressed with a high speed deformation. This may suggest that silicon may be plastically deformed with high speed deformation.     

Error and uncertainty in modeling and simulation

This article develops a general framework for identifying error and uncertainty in computational simulations that deal with the numerical solution of a set of partial differential equations (PDEs). A comprehensive, new view of the general phases of modeling and simulation is proposed, consisting of the following phases: conceptual modeling of the physical system, mathematical modeling of the conceptual model, discretization and algorithm selection for the mathematical model, computer programming of the discrete model, numerical solution of the computer program model, and representation of the numerical solution. Our view incorporates the modeling and simulation phases that are recognized in the systems engineering and operations research communities, but it adds phases that are specific to the numerical solution of PDEs. In each of these phases, general sources of uncertainty, both aleatory and epistemic, and error are identified. Our general framework is applicable to any numerical discretization procedure for solving ODEs or PDEs. To demonstrate this framework, we describe a system-level example: the flight of an unguided, rocket-boosted, aircraft-launched missile. This example is discussed in detail at each of the six phases of modeling and simulation. Two alternative models of the flight dynamics are considered, along with aleatory uncertainty of the initial mass of the missile and epistemic uncertainty in the thrust of the rocket motor. We also investigate the interaction of modeling uncertainties and numerical integration error in the solution of the ordinary differential equations for the flight dynamics.     

Miniature and MEMS-type vacuum sensors and pumps

In the paper, the observable trends of the actual research and development of selected types of miniature and MEMS-type vacuum sensors are presented. Some information about the new types of active vacuum gauges, which are offered by the leading manufacturers of the vacuum measurement instruments, is given. Next, the list of MEMS devices that need vacuum for proper operation is presented. Some aspects of vacuum-encapsulation of MEMS devices, on wafer level and package level are shown. The new conceptions of obtaining and maintenance of high and ultra-high vacuum in MEMS devices are described. They concern the conception of integration of a miniature orbitron pump on-chip with MEMS-type device or with vacuum part of the portable advanced instruments such as electron microscope, ion mass spectrometer, and free electron laser.