Nuclear energy conversion with stacks of graphene nanocapacitors

The efficiency of conventional techniques used to harvest energy in nuclear reactors lies around 35%. This limit exists, because the nuclear energy is converted to electrical energy via heat engines. We study an alternative approach where the kinetic energy of nuclear reaction products is directly converted into electric energy in a stack of charged capacitors with a gap size of 500 nm and graphene electrodes. Graphene is expected to be chemically and mechanically stable in high‐radiation environments, because its tensile strength of 130 GPa is very large, about 100 times larger than most metals. The dielectric strength of such nanocapacitors exceeds 1 GV/m, because avalanching is suppressed at small gap sizes. In a 1 GV/m electric field charged nuclear reaction products, such as 5.6 MeV alpha particles, come to rest in of a stack with 5000 nanocapacitors. We show that during the deceleration process more than 90% of kinetic energy of charged nuclear reaction products is converted to electric energy and stored as electric energy in the stack. Each stack is 2.5‐mm thick and produces a high‐voltage DC current. A device with a 1‐Ci²⁴¹Am source is expected to generate 22 mW of electric power.     

Flexible semi‐transparent silicon (100) fabric with high‐k/metal gate devices

Can we build a flexible and transparent truly high performance computer? High‐k/metal gate stack based metal–oxide–semiconductor capacitor devices are monolithically fabricated on industry's most widely used low‐cost bulk single‐crystalline silicon (100) wafers and then released as continuous, mechanically flexible, optically semi‐transparent and high thermal budget compatible silicon fabric with devices. This is the first ever demonstration with this set of materials which allows full degree of freedom to fabricate nanoelectronics devices using state‐of‐the‐art CMOS compatible processes and then to utilize them in an unprecedented way for wide deployment over nearly any kind of shape and architecture surfaces. Electrical characterization shows uncompromising performance of post release devices. Mechanical characterization shows extra‐ordinary flexibility (minimum bending radius of 1 cm) making this generic process attractive to extend the horizon of flexible electronics for truly high performance computers.

     

Characteristics improvement of HfO2/Ge gate stack structure by fluorine treatment of germanium surface

Chemical reactivity of fluorine molecule (F₂)-germanium (Ge) surface and dissociation of fluorine (F)-Ge bonding have been simulated by semi-empirical molecular orbital method theoretically, which shows that F on Ge surface is more stable compared to hydrogen. Ge MIS (metal insulator semiconductor) capacitor has been fabricated by using F₂-treated Ge(1 0 0) substrate and HfO₂ film deposited by photo-assisted MOCVD. Interface state density observed as a hump in the C-V curve of HfO₂/Ge gate stack and its C-V hysteresis were decreased by F₂-treatment of Ge surface. XPS (X-ray photoelectron spectroscopy) depth profiling reveals that interfacial layer between HfO₂ and Ge is sub-oxide layer (GeO_x or HfGeO_x), which is believed to be origin of interface state density.F was incorporated into interfacial layer easily by using F₂-treated Ge substrate. These results suggest that interface defect of HfO₂/Ge gate stack structure could be passivated by F effectively.     

基于虚拟仪器技术和网络的综合实验控制系统设计

为实现大型物理实验现场复杂多样的仪器控制,分析了物理实验的特点、过程、环境及仪器控制功能需求,利用虚拟仪器技术、计算机网络技术和数据库技术,建立了一套集成硬件和软件的综合控制管理信息系统,实现记录系统中示波器状态远程批量设置及波形数据自动采集、控制探测系统的高压电源并发加压或退压、保障各测试项目间测试仪器之间时间关联、监控UPS电量和远端现场图片或视频状态。给出了系统的关键的设计思路,列举了某型示波器控制的通用控制代码。结果表明,系统达到了一人总控或多人分权控制实验过程中多种多台仪器的目标,方便快捷地实现不同品牌不同类型示波器的相同功能。     

硅基MIS隧道二极管的研究

硅基ＭＩＳ隧道发光二极管为制造用于超大规模集成电路的硅基光器件提供了可能性,报道了ＭＩＳ隧道发光二极管的制作 过程,电流电压和发射光谱特性,讨论了负阻现象和发光机理。     

Carbon papers with conductive polymer coatings for use in solid-state supercapacitors

Conductive polymer-coated carbon papers have been fabricated through polymerisation of pyrrole-based monomers oxidised with various heteropolyacids. Smooth surfaces are obtained when multiple coatings are applied to the carbon surface and give good contact with the Nafion^® electrolyte. Cyclic voltammetry was used to study the electrodes and a.c. impedance and charge / discharge cycling was used to study membrane electrode assemblies (MEA). MEAs were fabricated using a hot-press technique.     

一种C/S与B/S混合结构的饭店管理系统

介绍了C／S和B／S混合结构对改变饭店管理模式的作用,讨论了用PB8．0构造C／S和B／S混合结构的基本体系,分析了C／S结构饭店管理系统向C／S和B／S混合结构转换中的移植策略和基本步骤．     

AlInGaN 310 nm ultraviolet metal-insulator-semiconductor sensors with photo-chemical-vapor-deposition SiO2 cap layers

Al_0.25In_0.04Ga_0.71N 310 nm near solar blind ultraviolet (UV) metal-insulator-semiconductor (MIS) sensors with different SiO₂ cap layer thickness were successfully fabricated. With appropriate SiO₂ layer thickness, the dark current of AlInGaN sensors was notably suppressed from 1.88 × 10⁻⁶ to 1.91 × 10⁻⁹ A, and the photo-generated carriers still could reach the electrodes by tunneling through the thin SiO₂ layer under the illumination. It could be clearly seen that cut-off occurred at around 300/310 nm while the responses above the bandgap were flat.     

耐高温、长寿命的铝电解电容器电解液研制

通过对铝电解电容器工作电解液的溶剂、溶质和添加剂的筛选,研制出耐高温、长寿命的铝电解电容器工作电解液。用此电解液制得的电容器具有低阻抗、耐高纹波电流、长寿命的特点,125℃耐久性试验达到5000小时。