纳米科技知多少

一、什么是纳米纳米是尺寸或大小的度量单位：千米（10^3）→米→厘米→毫米→微米→纳米（10^-9）；4倍原子大小，万分之一头发粗细。     

基于Hamaker假设的黏着接触弹性模型

为研究微纳米系统中的黏着接触问题，基于Hamaker假设和Lennard-Jones的势能定律，通过积分方法得到了球体与平面间的黏着力，同时结合经典弹性理论建立了一种新型的球体与平面黏着接触的弹性模型．该模型可以同时得到平面轮廓随间距的变形过程及黏着力和平面变形量随间距的变化规律，当球体半径较大时，所建模型与基于Derjaguin近似的黏着模型给出的结果基本一致，随着球体半径的逐渐减小，2种模型的差异逐渐增大，这是由于Derjaguin近似的误差随球体半径的减小而增大引起的．因此，当球体的半径趋近纳米级时，基于Hamaker假设的黏着接触模型消除了Derjaguin近似所带来的误差，可以更加准确地给出黏着力和平面变形量随间距的变化规律．     

超声波辅助水热合成条件对Fe3O4纳米微粒生长及磁性的影响

以FeCl3.6H2O,FeCl2.4H2O和NH3.H2O为原料,在超声波辅助下,用水热法合成了纳米磁性Fe3O4粒子,借助X射线衍射仪（XRD）、透射电镜（TEM）仪及振动样品磁强计（VSM）对产物Fe3O4进行分析,结果表明,当反应物物质的量之比（n（Fe^3＋）/n（Fe^2＋））为1.75,pH=13得到的前驱物,控制水热合成温度为140-160℃,水热处理时间为3-5 h时,可制备出纯相的反尖晶石结构的Fe3O4纳米微粒,随着水热合成温度的升高和时间的延长晶体发育越完整,平均粒径越大.磁性测量表明,饱和磁化强度和矫顽力也随着Fe3O4纳米微粒平均粒径的增大而增大.     

中药制剂技术课程改革初探

中药制剂技术与中成药生产紧密联系，它是高职高专中医药教育中药类专业学生和技能型中药人才必备的专业知识组成部分，在中药制剂的生产和研究中具有重要地位和作用。文章探讨了中药制剂技术传统教育的优缺点，指出了中药制剂技术课堂教学适应现代科技发展的必经之路。     

3,3''''-二羟基4,4''''-联苯二甲酸的合成和表征

联苯二甲酸类化合物是很好的刚性桥联配体,可用于制备纳米多孔材料.设计了一条制备联苯二甲酸类新配体的合成路线,以4氨基水杨酸为原料,经过4步反应最终合成了新配体3,3'-二羟基4,4'-联苯二甲酸,并通过红外光谱、核磁共振氢谱和元素分析进行了表征.     

纳米晶Ni-Mo-Fe催化阴极的制备与表征

利用射频磁控溅射的方法制备了纳米晶Ni-Mo-Fe合金薄膜,并将其作为太阳能光电化学制氢阴极催化膜.采用XRD、EDS对膜的晶型、成分进行了表征.用稳态极化曲线对膜的析氢电化学特性进行了测试.结果表明:在较高的工作压强、较高的衬底温度和较小的靶距下沉积的膜有较好的电化学性能,晶粒的细化、膜中Mo含量的增加及Ni含量的减少有助于析氢催化活性的提高.     

单质铟在空气中原位热氧化合成氧化铟纳米锥

以Au作催化剂，将金属铟在空气中加热到900-1000℃，在单质铟表面制备出In2103纳米锥．纳米锥的直径随着加热时间的延长和反应温度的升高而增加．采用拉曼光谱、扫描电镜和透射电子显微镜对产物进行了表征分析．结果表明，产物为立方相单晶结构的In2O3纳米锥，其直径和高度分别在0．08～0．7μm和0、5～3．1μm范围可调，且金作为催化剂在纳米锥的生长过程中起了非常重要的作用．基于此研究结果，提出了纳米锥的可能生长机理     

稀土纳米材料的特性及应用

本文概述了稀土纳米材料近几年的研究进展,重点介绍了稀土纳米材料在陶瓷、催化剂、永磁材料、发光材料、环保材料等领域的应用,对其发展前景进行了展望。     

Fabrication and superconducting properties of nano-SiC doped MgB2 tapes

Nano-SiC doped MgB2 tapes were prepared by the in situ powder-in-tube method. Heat treatment was performed at 650℃ for 1 h. XRD data indicate that SiC particles had reacted with the MgB2 during sintering process. MgB2 core seemed to be denser after SiC doping, and the critical temperature was slightly depressed. The critical current density Jc of the SiC doped tapes was significantly enhanced in magnetic fields up to 14 T compared to the undoped ones. For the 5% SiC doped samples, Jc was in- creased by a factor of 32 at 4.2 K, 10 T. The enhancement of Jc-B properties in SiC doped MgB2 tapes is considered to be due to the enhancement of grain linkages and the introduction of effective flux pining centers. The substitution of B by C in MgB2 grains is thought to be the main reason for the improve- ment of the flux pinning ability in SiC doped MgB2 tapes.     

Mechanism of the interaction between Au nanoparticles and polymerase in nanoparticle PCR

Nanoparticle PCR is a novel method to optimize DNA amplification. It performs well in improving specificity, enhancing sensitivity and speed. Several mechanisms were proposed in previous studies: one was based on the interaction between gold nanoparticles (AuNPs) and DNA while the other was attributed to the heat transfer property of AuNPs. In this paper, we propose that the interaction between AuNPs and DNA polymerase can significantly influence PCR. First, the addition of DNA polymerase can eliminate the inhibitory effects of excess AuNPs. Second, the addition of AuNPs will increase yield of the desired PCR product and make the optimum concentration of DNA polymerase move to higher value. Third, while excess polymerase might inhibit amplification efficiency, AuNPs can reverse this process and the yield of PCR amplification. Based on these results we propose a possible mechanism that AuNPs might modulate the activity of polymerase and improve PCR amplification.