Temperature and catalyst effects on the production of amorphous carbon nanotubes by a modified arc discharge

Large amounts of amorphous carbon nanotubes (ACNTs) were prepared with Co-Ni alloy powders as catalyst in hydrogen gas atmosphere by a modified arc discharging furnace which can control temperature during the electric arcing process. The experimental results indicate that the cooperative function of temperature and catalyst plays an important role in the soot production rate and the relative ACNT purity. When temperature increases from 25 °C to 700 °C, the soot production rate increases from around 1 g/h to 8 g/h, the best relative ACNT purity at 600 °C can reach up to 99% compared to the room temperature sample. Without catalyst, only plate graphite is formed at 25 °C and very few carbon nanotubes are found when temperature increases to 600 °C. TEM, SEM, HRTEM and XRD analysis showed that the as-prepared carbon nanotubes are almost amorphous. The soot production rate is 8 g/h and diameter range of amorphous carbon nanotubes is about 7-20 nm, respectively.     

国内垂直领域知识图谱发展现状与展望

为了充分展现国内在垂直知识图谱领域研究的现状,以垂直领域知识图谱为研究对象对其发展现状和趋势进行综述.对垂直领域知识图谱的定义和分类、架构和关键技术的发展现状进行了详细论述;针对垂直领域知识图谱的具体应用进行了论述,并以学术信息知识图谱和医药卫生知识图谱为例进行了详细介绍.最后对垂直领域知识图谱发展中存在的问题和对策以及未来的趋势进行了探讨.     

低钴储氢合金Ml0．9Mg0．1Ni3．4Co0．3Al0．3电化学性能研究

为了降低AB5犁储氢合金的成本，对低钴的Ml0．9Mg0．1Ni3．4Co0．3Al0．3合金的组织结构和性能进行了研究，并与工业储氢合金MmNi3.55Co0.75Mn0.4Al0.3进行了对比。实验结果表明：此低钴合金是由LaNi5主相和LaNi3第二相构成。它们的储氢晕（ω,％）分别为1．36％和1．37％，最大放电容量分别为320mAh／g和324mAh／g，循环稳定性为：300次充放电循环后，2种合金剩余容晕都是88％。但Ml0．9Mg0．1Ni3．4Co0．3Al0．3的高倍率放电性能明显优于MmNi3．55Co0．75Mn0．4Al0.3合金。主要原因是由于LaNi3第二相的乍成不仪提高了合金颗粒表面的电化学催化活性，而且提高了结构韧性从而抵消了低钴合金颗粒粉化的不利影响。     

基于嵌入式系统的IC卡电表可靠性研究

在嵌入式系统应用中抗干扰是一个很重要的问题。特别是在与电力网相关的控制系统的设计和实际制作过程中,系统的可靠性差,将会引起许多意想不到的问题。我们在基于嵌入式系统的IC卡电度表中除采用常规软件抗干扰措施外,针对实际情况还采取了一些特殊技术,并取得了很好的效果。     

Evaluation across and within collaborative manufacturing networks: a comparison of manufacturers’ interactions and attributes

Evaluation on collaborative manufacturing network (CMN) structure characteristics has important implications for network operations such as production decision-making, product recovery, creating consensus. Several recent studies suggest that augmenting network structure with nodes’ attributes can provide a more fine-grained understanding of the network. However, there have been few studies to provide a systematic understanding of these effects in a CMN at scale. This gap is bridged using an industrial printing machinery CMN data-set collected on a web-based producing and outsourcing service platform. Novel phenomena with respect to both interaction and attribute metrics across and within the CMNs are observed. Moreover, although many studies employ either interaction or attribute data to study the relative roles of manufacturers in a CMN, relatively little is known about the relationship between these two types of data. This study explores this relationship by comparing two defined metrics (i.e. relational capability and node capability), which evaluate the manufacturers’ interactions and attributes, respectively. We examine to what extent the two metrics of manufacturers correlate with each other, and how possible dissimilarities and similarities can be explained based on the collected industrial CMN data-set. The insights thereby provide a better basis for efficient operations decision-making in CMN.     

基于数据密码子的异常入侵检测系统的研究

文章以基因工程中的基因密码子的作用机理作为理论仿真基础,利用生物免疫学中的一种全新的免疫模式——危险模式,来建立起一个基于数据密码子的系统调用异常入侵检测系统。该系统克服了传统免疫算法的计算规模庞大、特征复杂、自适应进化能力差等缺点。     

An Embedded Internet interface system

This article has introduced a method to connect the embedded system with Internet, and given a circuit of embedded system connect.     

超细晶1.73C超高碳钢的组织和性能

将1．73C％超高碳钢（UHCS-1．73C）的钢锭经过低应变、多道次锻造，加热淬火、高温回火后得到超细晶粒、球状碳化物组织，再进行循环感应热处理，得到超细晶粒马氏体基体上分布超细球状碳化物的组织，研究其组织和性能与循环感应热处理之间的关系．结果表明，随着感应加热淬火循环次数增加，组织中出现板条马氏体且数量增加，马氏体片变短、钝化，碳化物颗粒更圆整，压缩屈服强度升高，塑性增大．循环感应淬火4次后（不回火）屈服强度1105MPa，断裂强度1992MPa，压缩率9．8％．     

Si元素对Ti基储氢合金电化学性能的影响

为了改善Ti基储氢合金的电化学性能，采用Si元素部分替代Mn元素的方法，分析研究了Ti基储氢合金Ti03Zr0．225V0.25Mn0．25-xNi0.5Six的相结构及电化学性能。结果表明，合金均由六方结构的C14型Laves主相和立方结构的TiNi第二相构成；随着Si元素替代量x的增大，合金的活化性能降低，而循环稳定性得到很大程度的改善。     

Interfacial polymerization of morphologically modified polyaniline: from hollow microspheres to nanowires

BACKGROUND: Polyaniline (PANI) has attracted much attention in many fields due to its chemical and physical properties, and different nanostructures of PANI changing from one‐dimensional to three‐dimensional have been obtained. By changing the concentration of cetyltrimethylammonium bromide (CTAB), the morphology of hydrochloric acid‐doped polyaniline could be changed from one‐dimensional nanoneedles or nanowires with a network structure (50–100 nm in diameter) to three‐dimensional hollow microspheres (ca 400 nm in outer diameter) via combining interfacial polymerization and self‐assembly process. RESULTS These different nanostructures of PANI were proved using scanning electron and transmission electron microscopies. A plausible mechanism of the formation of the changeable nanostructures of PANI may be different from that of interfacial polymerization without surfactant or a traditional homogenous reaction system using CTAB as surfactant. CONCLUSION The results obtained from Fourier transform infrared spectrometry, X‐ray diffraction and the four‐probe method showed that the molecular structure of PANI does not change with increasing CTAB concentration, but crystallinity and conductivity of PANI increase with surfactant concentration. Copyright © 2007 Society of Chemical Industry