多孔SiO2凝胶玻璃中孔的控制与表征

较全面地讨论了用溶胶－凝胶法制备多孔ＳｉＯ２的研究中，关于孔的工艺控制及表征技术的发展状况，阐述了多孔ＳｉＯ２中纳米级孔在纳米材料科学。精细复合技术及其它相关领域中的重要意义。     

制备纳米复合材料的天然矿物--蒙脱石

纳米技术被誉为 2 1世纪经济增长的发动机。纳米技术涉及的范围很广 ,而纳米材料是纳米技术发展的体现。纳米材料可以简单地认为 :在三维空间中其基本单元体至少有一维处于纳米尺度范围内 ;当粒子尺寸处于纳米量级时 ,会引起材料在宏观物理、化学性能上的巨大变化的材料。纳米材料大多是人工制造的 ,虽然如此 ,应用天然纳米材料依然是世界材料科学的热门课题。膨润土的主要矿物原料———蒙脱石是目前最具有商业价值、能制成纳米复合材料的天然矿物之一。1　蒙脱石的特殊晶体结构蒙脱石是由二层硅氧四面体片夹一层铝 (镁 )氧 (氢氧 )八面体…     

模板法制备结构可控纳米材料的研究进展

综述了模板法制备结构可控纳米材料的研究进展,讨论了模板法可控制备纳米材料的原理及高度有序自组装的纳米多孔Al2O3模板的形成机理.重点介绍了纳米材料的可控制备方法,主要包括纳米多孔Al2O3模板法、聚合物模板法和生物模板法.其中纳米多孔Al2O3模板法又分为电化学纳米多孔Al2O3模板合成法和电化学诱导的溶胶-凝胶方法等.根据材料的物化性能,选用适合的模板,采用合理的工艺路线,可以制备出结构可控的纳米材料.     

纳米材料结构特征

根据纳米材料的结构特点,我们把它们分为两类。一类是具有高密度的紧密结构,如文献[1]中报导的纳米铁;只一类是低密度具有大量纳米尺寸空洞的无规网络结构,如文献[2]中报导的纳米氧化锡。两者的根本差别在于是否存在高体积分数的纳米空洞。紧密结构纳米材料具有大量的晶界结构,而多孔网络结构纳米材料具有大量的表面结构,这导致两者物化性质的巨大差异。     

掺杂纳米材料对等离子喷涂涂层组织性能的影响

对AT13粉掺杂纳米级材料Al2O3 13wt％TiO2的复合粉在等离子喷涂中的应用进行了研究，包括纳米级材料的分散、掺杂、制备微米粉及喷涂工艺参数。结果证明：掺杂纳米材料的涂层较常规微米级涂层结构有明显改善，涂层组织细化、分布均匀，孔隙率降低；涂层残余应力降低，亚微裂纹减少，耐磨耐蚀性能明显提高。纳米材料的加入，改善了喷涂熔融态粉末的流动性及平铺性能，改变了涂层晶粒生长机制。     

消息报道

浙江华特集团建成大规模　　　纳米膨润土生产线1月 14日 ,杭州市科技发展计划第一批重大攻关项目———浙江华特集团年产 30 0 0ｔ纳米级有机膨润土生产线竣工投产 ,并通过了有关部门的验收。这标志着华特集团实现了利用高新技术改造传统产业的历史跨越 ,“华特”从而成为国内规模最大并与国际接轨的纳米级膨润土生产基地。预计达产后 ,每年可新增销售额 1亿元。膨润土是指以蒙脱石矿物为主或蒙脱石矿物达到可利用含量的粘土岩 ,它在工业上用途非常广泛。膨润土的主要矿物———蒙脱石因其具有天然片层结构 ,是目前最具有商业价值能制成纳…     

模板法制备一维聚合物纳米材料的研究进展

一维聚合物纳米材料具有特殊的结构和性能，在纳米器件、药物释放、纳米传感器等方面有应用前景。采用模板法可以制备结构可控、排列规整的一维聚合物纳米材料。通常选用具有纳米孔洞的多孔膜作模板，通过在模板孔洞中进行电化学或化学聚合，或将聚合物的溶液或熔体引入孔洞中进行制备。文中综述了近年来采用模板法制备一维聚合物纳米材料的研究进展。     

纳米材料在树脂基烧蚀材料中的应用

综述了纳米材料在树脂基烧蚀材料中的应用。概述了纳米材料的特性，介绍了纳米炭粉、纳米炭纤维、蒙脱土及多面体低聚半硅氧烷（POSS）等纳米材料在烧蚀材料中的应用概况，并提出了纳米材料在这一领域的发展方向及存在问题。     

微乳法制备超细级纳米材料的研究现状与进展

微乳法制备超细级纳米材料在各个科学领域中有着广泛的应用前景。综述了应用微乳法制备超细级纳米材料的原理，叙述了制备超细级纳米材料的主要影响因素以及近3年来在超细级纳米材料制备方面的现状，并探讨了该领域的发展方向。     

纳米ZnS的研究现状及应用

总结了纳米级ZnS的制备方法及其特点,综述了纳米ZnS的表征、掺杂及应用,并就近年来国内外对硫化锌的研究进行了总结,说明研究硫化锌复合材料是今后的趋势.大量资料表明ZnS纳米材料仍具有广阔的应用前景及研究价值.     

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.     

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。     

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。     

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.