SEM analysis of the changes of carbon layer structure of mesocarbon microbeads heat-treated at different temperatures

Mesocarbon microbeads (MCMB) with narrow size distribution, excellent sphericity and no obvious conglutination have been prepared with a coal tar pitch containing quinoline insolubles (QI) as the raw material. Optical microscopy and scanning electron microscopy (SEM) are used to examine the structure of the MCMB. It has been found that SEM technique shows the structural information of MCMB clearly in the form of micrographs even when the structure of MCMB is complex, while the optical technique is useful for analysis of the regular structure of the mesophase spheres but cannot be effectively used to analyze either the complex structure of the green MCMB or the structures of the further heat-treated ones at different temperatures. According to the characteristics of the carbon layers, the structures of the as-prepared MCMB in the present experiment could be classified as (I) Parallel Layer type structure and (2) Bent Layer type structure with the carbon layers gathering at one or two points in the MCMB. In the experiments, SEM is also utilized to investigate the structures of MCMB that are heat-treated at different temperatures. It has been found that the MCMB without any further heat-treatment show no layered-carbons, while the ones heat-treated at temperaturehigher than 1000℃ exhibit obvious layered carbons across their sections. When increasing the heat-treatment temperature, the carbon layers become thinner and flatter.     

太空诊所

<正>如今,越来越多的宇航员进入了太空,工作在人类探索宇宙的最前线。然而,太空环境也影响了宇航员的身体健康,导致一些太空疾病出现。为了能及时医治这些疾病,美国科学家设计出了由计算机控制的太空诊所,计划把它安装在永久性空间站内。太空诊所内配有小型现代化诊断器,如X光机、B超机和CT扫描机,可用于对宇航员做     

有机纯度标准物质定值技术研究进展

标准物质的定义是经过一系列的校准装置、进行评价测量所赋值的一种物质与材料,其中有一种是具有溯源新质的程序,来确定相关的测量,能够标准的测量出数据,作为准确的计量单位。有机标准物质是广泛的被色谱分析领域所研究,在这片领域里有一定的定值标准,它的化学纯度定值技术的计量标准是物质物质准确量值的重点。该文研究了多种的定值技术,然后对每种技术的效果进行比较,对有机标准物质化学纯度定值技术的发展有了更好的诠释和引导。     

未来50年科技发展预测

美国政府属下的＂地平线扫描中心＂根据数百名专家的观点整理出246项见解,展望了从大脑特质到宇宙航行等各个领域在今后50年的发展趋势。医学在今后的数十年里,干细胞和核糖核酸（RNA）干预疗法等医学发展将会继续取得进步。它们将给人类带来治愈不治之症的希望,最终攻克仅仅在几年前被认为不可能解决的难题。然而,生物学领域的其他发展可能导致我们对大脑和躯体更带根本性的重新建构。     

基于数字图像的大空隙沥青混凝土离散元模型

为了从细观角度深入分析大空隙沥青混凝土性能,利用CT扫描获取PAC-13大空隙沥青混凝土内部图像,将三维重构的切片图像和CT横向扫描图进行阈值分割,通过体视学理论选取与真实级配最相近的图像作为集料、空隙结构提取对象,建立了像素边长为0.5 mm的离散元模型,并进行单轴压缩虚拟测试.结果表明:三维重构切片图的级配误差比横向扫描图级配误差小了约20%,重构的切片图级配更具代表性;该模型实现的虚拟单轴压缩试验强度值与室内单轴压缩试验强度值相差小于3%,该模型具有很好的可靠性,这种数字图像建模的方法为研究大空隙沥青混凝土内部细观结构提供了参考.     

浅谈三维人体扫描技术在服装个性化定制领域的应用

随着三维人体扫描技术的不断发展,其在服装定制领域中的应用日益广泛,这也是服装工业生产的必然发展趋势。采取这种技术进行服装定制,客户仅需要提供三围尺寸数据。与传统手工测量方式不同,这种设计与软件结合在一起,更具精确性和方便性。本文主要研究三维人体扫描技术在服装个性化定制领域的应用,希望能为相关人员带来一些帮助。     

An effective amperometric biosensor based on graphene modified gold nanowire arrays for glucose detection

A novel glucose biosensor based on graphene nanosheets （GNs） modified gold nanowire arrays （AuN- WAs） electrode was constructed. Highly ordered gold nanowire arrays were prepared by direct electrodeposition in anodic aluminum oxide templates. GNs were synthe- sized through a public route involving graphite oxidation, exfoliation, and chemical reduction. Field emission scan- ning electron microscope and high-resolution transmission electron microscope were employed to characterize the as- prepared AuNWAs and GNs. Glucose oxidase was immobilized on the surface of GNs-AuNWAs modified electrode via a cross-linking method. The cyclic voltam- metry results showed that the GNs-AuNWAs-based glu- cose biosensors have high catalysis activity to hydrogen peroxide （H2O2） than those modified with GNs or AuN- WAs only. Furthermore, amperometric response was employed to detect glucose concentration owing to its simplicity, high selectivity, and relative low cost. Glucose biosensors based on GNs-AuNWAs showed excellent performance with high sen- sitivity of 40.25 μA cm^-2 （mmol/L）^-1, low detection limit of 0.02 mmol/L, and a linear range from 0.02 to 3 mmol/L.     

海阔潮涌竞风流--中国空间技术研究院卫星应用产业科学发展扫描

近则两三百千米，远则几万千米，在太空中遨游的卫星看似遥远，实际上却离我们很近。生活中，我们时常能发现“卫星”的影子，感受到它们的存在，与生活密切相关的环境监测、抢险救灾、路径导航、广播电视等很多活动都离不幵卫星技术成果的应用。作为新一代信息技术产业的重要组成要素，卫星应用已经成为社会生活不可或缺的一部分，深刻影响着国民经济各行业的发展进程。     

Atmospheric-pressure Air Plasma Treatment of Polyester Fabrics for Inkjet Printing with Pigment Inks

Without any preprocessing,polyester fabric has lower ability to hold on water and inks due to the smooth morphology of polyester fibers. Therefore, patterns directly printed with pigment inks have poor color yields and bleed easily. Pretreatments of polyester fabric were carried out with atmospheric air plasma under different experimental conditions. After plasma treatment the samples were printed with magenta pigment ink. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyse...     

基于三维扫描技术检测针织物的起毛起球特征值

利用三维扫描仪获取了针织物表面坐标数据,在等间距网络规整预处理和小波分析降噪处理后,研究了毛球与背景分离的方法,并通过相关算法和计算机处理获取了毛球的个数、面积和体积等特征值.试验结果表明,该方法可以自动检测针织物起毛起球特征值,具有较高精度和较好可视性,并且不受针织物色彩及纹理的影响.