导电TiO_2在聚酰胺中分散性的研究

设计制备了导电TiO2材料,使用硝酸溶液对其进行表面活性处理,使用表面处理以及未处理的导电TiO2与聚酰胺分别混合造粒,再经熔融纺丝制备纤维。测试表明未经处理的导电TiO2在基体中发生团聚,纤维不具有导电性能;经表面处理后可以很好的分散于基体中且与基体相容性良好,纤维具有良好的导电性能;导电TiO2在基体中分散好有利于共混物结晶。对其导电机理进行了研究,结果表明:当导电TiO2均匀分散于基体中形成三维点状网络结构时,隧道导电为主。     

电磁干扰产生以及屏蔽技术

本文论述了电子系统中电磁干扰的来源、传播途径以及可以采取的防护措施,主要对防护措施中的电磁干扰缝隙屏蔽设计进行了讨论。     

基于宏观尺度纳米线组装体的透明柔性导电电极和弹性导体研究取得新进展

最近。中国科学技术大学俞书宏教授研究组围绕如何高效宏量组装纳米导电基元．特别是银纳米线,开展了一系列探索研究。成功研制了基于纳米线组装体的二维柔性透明导电电极和三维弹性导体．为今后规模化制备柔性透明导电电极和弹性导体提供了新的制备技术。有关研究工作由特任副研究员刘建伟和2012级博士生高怀岭等完成。     

Study of photocurrent generation in InP nanowire-based p＋-i-n＋ photodetectors

We report on electrical and optical properties of p＋-i-n＋ photodetectors/solar cells based on square millimeter arrays of InP nanowires （NWs） grown on InP substrates. The study includes a sample series where the p＋-segment length was varied between 0 and 250 nm, as well as solar cells with 9.3% efficiency with similar design. The electrical data for all devices display clear rectifying behavior with an ideality factor between 1.8 and 2.5 at 300 K. From spectrally resolved photocurrent measurements, we conclude that the photocurrent generation process depends strongly on the p~-segment length. Without a p＋-segment, photogenerated carriers funneled from the substrate into the NWs contribute strongly to the photocurrent. Adding a p＋-segment decouples the substrate and shifts the depletion region, and collection of photogenerated carriers, to the NWs, in agreement with theoretical modeling. In optimized solar cells, clear spectral signatures of interband transitions in the zinc blende and wurtzite InP layers of the mixed-phase i-segments are observed. Complementary electroluminescence, transmission electron microscopy （TEM）, as well as measurements of the dependence of the photocurrent on angle of incidence and polarization, support our interpretations.     

Contactless probing of the intrinsic carrier transport single-walled carbon nanotubes

Intrinsic carrier transport properties of single-walled carbon nanotubes have been probed by two parallel methods on the same individual tubes： The contactless dielectric force microscopy （DFM） technique and the conventional field-effect transistor （FET） method. The dielectric responses of SWNTs are strongly correlated with electronic transport of the corresponding FETs. The DC bias voltage in DFM plays a role analogous to the gate voltage in FET. A microscopic model based on the general continuity equation and numerical simulation is built to reveal the link between intrinsic properties such as carrier concentration and mobility and the macroscopic observable, i.e. dielectric responses, in DFM experiments. Local transport barriers in nanotubes, which influence the device transport behaviors, are also detected with nanometer scale resolution.     

Effect of Deep Cryogenic Treatment on Electrical Conductivity of Cu-Base Multicomponent Alloy

The electrical conductivity of Cu-base multicomponent alloy before and after deep cryogenic treatment at different situations were measured by conductance instrument, its microstructures were also characterized by optical microscope, and the effect of deep cryogenic treatment on the electrical conductivity ofCu-base multicomponent alloy was studied in this paper. The results show that deep cryogenic treatment can change the electrical conductivity of Cu-base multicomponent alloy, and the electrical conductivity increases with the extension of deep cryogenic treatment time, when deep cryogenic treatment time exceeded 100 min, electrical conductivity increases slightly. However, the higher electrical conductivity can be obtained by aging at 500 ℃ for 30min after deep cryogenic treatment.     

欧盟创新型大功率超级电容器问世

正数秒钟内完成充电,可以让您的笔记本电脑至少工作一个月,创新型的大功率超级电容器(Supercapacitors)是欧盟第七研发框架计划(FP7)提供全额资助、由瑞典查尔姆斯理工大学(Chalmers University of Technology)伽里.基纳瑞(Jari KINARET)教授领导的、欧洲AUTOSUPERCAP研发团队     

纳米材料开启绿色印刷革命

正北京市重大科技成果转化和产业化项目"基于纳米材料的绿色印刷电路制备技术产业化"顺利通过专家组验收,标志着北京市纳米银导电墨水和基于纳米材料绿色印刷电路的RFID射频标签天线实现产业化,对于推动我国纳米绿色印刷电路产业发展具有重要意义。纳米材料绿色印刷电路制备技术,是将纳米导电材料直接在纸或膜表面印刷形成电路。该技术可取代传统的电路蚀刻工艺,具有工艺简单、成本低、基材丰富、易回收利用     

石墨烯隐形眼镜 佩戴获超级夜视能力

正美国密歇根大学研究人员最新研制一种智能隐形眼镜,使佩戴者具有"红外夜视"能力。研究小组称,在镜片之间夹入石墨烯,能够建造一种具有捕捉可见光和红外线能力的传感器。现已建造一个比手指甲更小的原型,专家称未来将这种智能隐形眼镜应用于士兵,以及需要黑暗中观察周围环境的群体。这种镜片充分利用了石墨烯"超级传感器"的性能,石墨烯内的电子能够像光子一样高速运动,是硅中光子速度数十倍。它可作为一种"热载流子",产生的效应可以测量、加工处理,转换成为图像。     

氟碳树脂基导电涂料的制备及其性能研究

以氟碳树脂为基体,掺铝氧化锌粉体为导电填料,制备导电性能优良的单组份导电涂料。借助热重-差热、X射线衍射、电镜等分析手段,探讨了掺铝氧化锌粉体的添加量和导电粉体的改性对导电涂料电性能、热稳定性和力学性能的影响。结果表明,当用乙烯基三乙氧基硅烷和硅烷偶联剂改性的导电填料掺量为35%时,制备的导电涂料性能最优,其体积电阻率为8.89×108Ω·cm、拉伸强度和断裂伸长率分别为19.36 MPa和200.45%。