在真空室内表面形成非蒸发吸气剂膜（TiZrV）抽气层的特性研究

TiZrV合金吸气剂材料能够对气体分子进行化学吸附，并且最低激活温度Ta只有180℃，可以广泛地应用在各种设备中，例如粒子加速器，惰性气体净化装置，H2等离子体净化装置，托克马克中的H2回收装置。本论文通过计算设计，建立了二极直流磁控溅射系统，在国内首次对加速器细长真空管道进行了TiZrV膜层溅射沉积，使其成为管道泵。测试结果表明真空单元在TiZrVNEG处理后极限压力降低，同时压力分布梯度过大的问题得以解决；在镀膜系统的结构设计中创造性地加入了可压缩波纹管，解决了细长管道镀膜中阴极下垂引起短路及溅射距离不等的难题，使阴极始终处于管道中心，保证了镀膜的均匀性。论文对沉积膜层从基体材料、基体的表面粗糙度、基体温度、膜层成分对激活温度和真空性能的影响等方面进行了研究。对于理想状态下的磁控溅射，不同的基体材料会导致不同的膜层形态，但是具有相同的晶体结构和激活温度。通过沉积在粗糙的铜基材来增大表面粗糙度，不能加速激活过程，但明显增大了抽速和表面吸附容量。将溅射沉积过程中的基体温度（Ts）升高到250℃可以在不改变晶体结构的同时增大膜层的表面粗糙度。对于获得理想的粘附系数和表面吸气容量来说，基体温度Ts=250℃。使用粗糙的基体材料并在镀膜时将基体温度Ts保持在250℃可以获得最大的表面吸气容量。最大的抽速获得通过加热膜层到250℃。温度进一步升高，抽速开始下降

CSR真空控制系统的研究

本论文主要解决CSR真空系统的控制实现与连锁保护问题。 HIRFL-CSR（Heavy Ion Research Facility at LanZhou-Cooling Storage Ring兰州重离子冷却储存环）是国家重大科学工程。为了保证CSR正常运行，超高真空系统的平均真空度必须达到6×10-9Pa，超高的真空度来之不易，CSR上任何一处真空设备发生故障，就会破坏真空度，所以CSR必须具有响应速度快、安全可靠，稳定性好的真空控制与连锁保护系统。 HIRFL-CSR真空设备有离子泵电源、分子泵、钛升华泵、阀门、真空计等。分子泵只在粗抽时使用，钛升华泵为间歇升华，因此不需要监控。需要显示和控制的设备为离子泵电源、真空计和真空阀门。通过对CSR上每个真空计的真空度数据的监测和真空阀门状态的采集，一旦真空度降低到一定阈值，立即关闭相应位置阀门（保护真空）,并给出故障报警，从而实现真空系统的连锁保护。 真空控制系统以嵌入式处理器ARM、复杂可编程逻辑器件CPLD和微控制器MSP430为核心，实现了远程数据采集、数据显示和自动控制等功能。本系统可以进行现场监控与调试，也可以通过集成的100Mbps以太网接口电路进行远程监测与控制，CSR上各处真空度和真空阀门状态自动传送到中央控制中心，中控中心也可以发送命令查询当前真空设备状态和各种读数。 本文主要介绍了基于ARM、CPLD和MSP430的嵌入式真空控制系统的设计与实现。内容主要包括(1)系统各部分硬件电路设计与真空控制功能实现 ，硬件系统调试 。(2)嵌入式uClinux操作系统构建和在其上进行的应用程序，设备驱动程序，串行通信程序的开发。（3）CPLD的VHDL程序和MSP430的C430程序设计。 本文目的是解决CSR真空控制系统问题，但对于许多远程数据采集与控制等问题的解决有重要参考价值

ECR离子源高真空微调针阀控制系统

本论文首先介绍ECR（电子回旋共振）离子源的基本原理及其发展，在此基础上讲述了近物所的14.5GHzECR离子源的结构和特点。本论文主要内容是介绍所研制的适用于30KV高压端的ECR离子源高真空微调针阀控制系统。此系统被控对象是位于ECR源上的高真空微调针阀，它与地面之间有20～30KV的电位差。论文中首先阐述此控制系统研究的背景，并对ECR离子源电气参数控制的特点进行了说明。根据被控对象的情况以及对系统提出的指标，详细讲述了此控制系统的软、硬件实现。硬件包括步进电机、步进电机驱动器、轴编码器等。软件包括译码编程。然后从总体介绍此控制系统的功能结构，再分步讲述发射器、接受器、译码等各功能模块的实现过程。此控制系统的最大特点是使用光路实现高压绝缘，这为解决位于ECR离子源高压端器件的控制问题提出新思路。本系统的光路采用红外线发射接收系统，以空气为传输介质，依据光信号的有无接收控制信息，此方式效果好、易于实现。在系统中，使用光路传输装置定位，聚集透镜聚集，增加信号强度，提高抗干拢能力。而且此光路传输系统价格便宜，易于实现，可靠性好。在整个控制系统方案调研期间，对各种控制方式进行了比较和实验，在此基础上，确定了一个比较经济实用和具有高可靠性的方案。经过设计电路原理图、绘制印制线路板、加工印制线路板、购买元器件、组装电路后，首先成功地进行了离线调试，最后，将整个系统模拟实际环境进行调试实验。整个系统实现了稳定可靠的工作，达到了预期的设计指标，精度好于要求的千分之一。由于时间紧张和条件的限制，该系统还未在现场设备上进行实验。因此，在今后的工作中，此控制系统还需要在条件具备时，在现场设备上进行实验和考验。此外，为满足国家大科学工程兰洲重离子冷却储存环的要求，我参与了在14.5GHz ECR离子源上进行afterglow工作模式的实验，首次产生了高电荷态脉冲束流Ar~(11+)和Ar~(12+)。论文最后一部分给出了初步实验结果，并对结果进行了分析和解释。

HIRFL-CSR超高真空烘烤系统的设计及建造

为了满足兰州重离子加速器冷却储存环6×10-9Pa的真空度要求，必须建立温度在200-300℃、控制良好的在线烘烤系统。HIRFL-CsR真空系统是一个超大型超高真空系统，系统全长50Om，总内表面积263m2（不包括装入真空室的其它元件），系统由500多个非标加工件构成，同时和磁铁、电子冷却、高频、高压静电等设备相连。本论文主要从烘烤温度确定、热电偶、加热及绝热套、功率计算及分布、烘烤控制、样机测试结果等几个方面介绍了兰州重离子加速器冷却储存环（HIRFL-CSR）超高真空烘烤系统。用理论和实验的办法分析了烘烤对系统中残余气体成分的显著影响：研制了功率分布均匀、安装拆卸方便的烘烤夹克，尤其研制新型纳米粉绝热材料，测定了其绝热性能；在国内储存环系统中，首次应用计算机控制烘烤全过程，实现了安全、省力的运行。

HIRFL-CSR真空测控系统

兰州重离子加速器冷却储存环（HIREL-CSR）真空系统是一个超大型超高真空系统，系统全长约500米，系统由1000多个非标加工工件、真空获得设备、真空计和阀门构成，与各类磁铁、电子冷却、高频、高压静电偏转板等设备相连［1］。兰州重离子加速器冷却储存环的真空要求很高所以我们选用了国外性能比较优秀的泵配合先进的工艺。实现了全环平均真空度达到6X10-9Pa。HIRFL-CSR真空设备有离子泵，分子泵，钦升华泵，阀门，真空计，质谱计等。需要显示和控制的设备为离子泵，真空计，阀门和质谱计。分子泵只在粗抽时使用，钦升华泵为间歇升华，因此不需要监控。我们要对储存环上的每个真空计的读数进行监测，通过对真空计的监测，实现报警，真空系统的连锁和对真空设备采取自动保护措施。本文主要从各种真空设备（真空计、真空泵、阀门）控制等几个方面介绍HIRFL-CSR超高真空控制系统。

CSR超高真空排气系统的研究

兰州重离子加速器冷却储存环（HIRfL-CSR）属于国家“九·五”重大科学工程，全长约500m，超高真空系统贯穿整个装置。CSR真空排气系统是超高真空系统的重要组成部分。本论文从CSR真空系统排气系统的选择，排气系统的性能测试以及配置优化，压力分布计算，残余气体分析等多个方面对兰州重离子加速器冷却储存环（HIRFL-CSR）超高真空排气系统做了研究。计算和实验结果均表明CSR真空系统排气系统的选择配置完全满足3．5X10-gPa的真空度要求。

The effect of methanol and ethanol cross-over on the performance of PtRu/C-based anode DAFCs

In the present work, the cross-over rates of methanol and ethanol, respectively, through Nafion(R)-115 membranes at different temperatures and different concentrations have been measured and compared. The changes of Nafion(R)-115 membrane porosity in the presence of methanol or ethanol aqueous solutions were also determined by weighing vacuum-dried and alcohol solution-equilibrated membranes. The techniques of anode polarization and adsorption stripping voltarnmetry were applied to compare the electrochemical activity and adsorption ability, respectively. To investigate the consequences of methanol and ethanol permeation from the anode to the cathode on the performance of direct alcohol fuel cells (DAFCs), single DAFC tests, with methanol or ethanol as the fuel, have been carried out and the corresponding anode and cathode polarizations versus dynamic hydrogen electrode (DHE) were also performed. The effect of alcohol concentration on the performance of PtRu/C anode-based DAFCs was investigated.

Polymeric fullerene oxide films produced by decomposition of hexanitro[60]fullerene

A new poly(fullerene oxide) thin film material has been fabricated by thermal activation and electron bombardment on hexanitro[60]fullerene (HNF) film deposited on a An substrate, all under vacuum conditions. The reaction products in the polymerization process are analyzed by XPS, UPS, IR, TGA-MS and LDI-MS techniques. It is found that the main effect of thermal and radiation treatments is to induce cleavage of -NO bonds from HNF molecules resulted in the release of nitric oxide gas and the formation of fullerene-bound oxyradicals, C-60-C-6. Spectroscopic evidence strongly suggests that rearrangement of fullerenic nitro moieties into nitrito groups is involved in the HNF decomposition process prior to the generation of reactive oxyradical intermediates. Consequently, the intermolecular coupling reaction of these oxyradicals leads to carbon polymer networks containing oxygen-bridged fullerenes. The thermally generated polymeric thin film is stable up to 900 K. Electron bombardment is also effective in both the decomposition of -NO2 groups and the removal of -OH groups present in HNF films. UV irradiation at 365 nm alone is shown to be not as efficient for the polymer formation. (C) 2003 Elsevier Ltd. All rights reserved.

Chemisorption and reaction characteristics of methyl radicals on Cu(110)

Methyl radicals are generated by pyrolysis of azomethane, and the condition for achieving neat adsorption on Cu(110) is described for studying their chemisorption and reaction characteristics. The radical-surface system is examined by X-ray photoemission spectroscopy, ultraviolet photoemission spectroscopy, temperature-programmed desorption, low-energy electron diffraction (LEED), and high-resolution electron energy loss spectroscopy under ultrahigh vacuum conditions. It is observed that a small fraction of impinging CH3 radicals decompose into methylene possibly on surface defect sites. This type of CH2 radical has no apparent effect on CH3(ads) surface chemistry initiated by dehydrogenation to form active CH2(ads) followed by chain reactions to yield high-mass alkyl products. All thermal desorption products, such as H-2, CH4, C2H4, C2H6, and C3H6, are detected with a single desorption peak near 475 K. The product yields increase with surface coverage until saturation corresponding to 0.50 monolayer of CH3(ads). The mass distribution is, however, invariant with initial CH3(ads) coverage, and all desorbed species exhibit first-order reaction kinetics. LEED measurement reveals a c(2 x 2) adsorbate structure independent of the amount of gaseous exposure. This strongly suggests that the radicals aggregate into close-packed two-dimensional islands at any exposure. The islanding behavior can be correlated with the reaction kinetics and is deemed to be essential for the chain propagation reactions. Some relevant aspects of the CH3/Cu(111) system are also presented. The new results are compared with those of prior studies employing methyl halides as radical sources. Major differences are found in the product distribution and desorption kinetics, and these are attributed to the influence of surface halogen atoms present in those earlier investigations.

Ionic liquids Supported Growth of Highly Ordered Microdroplets Induced by Fluidic Leakage at Poly(dimethylsiloxane) Interfaces

"Fluidic leakage" caused by vacuum force at the reversible sealing poly(dimethylsiloxane) (PDMS) interfaces was converted to one useable avenue, which led to formation of highly ordered surfactant microdroplets functionalized with ionic liquids (ILs). Vacuum force is the prerequisite to lead constant microsolutions to diffuse to the PDMS interfaces. Imidazolium ions of ILs rendered structural rearrangement of the surfactant aggregates and the ordered droplets formation.

Undercut structure fabricated by complementary-structure micropatterning technique for the passive-matrix display of organic light-emitting diodes

This paper reports a new patterning method, the complementary-structure micropatterning (CSMP) technique, to fabricate the undercut structures for the passive-matrix display of organic light-emitting diodes (OLEDs). First, the polyvinylpyrrolidone (PVP) stripe patterns with a trapeziform cross-section were formed by micromolding in capillaries. Then the photoresist was spin coated on the substrate with the patterned PVP stripes and developed in water.

Vertical structure p-type permeable metal-base organic transistors based on N,N '-diphentyl-N,N '-bis(1-naphthylphenyl)-1,1 '-biphenyl-4,4 '-diamine

In this article, vertical structure p-type permeable-base organic transistors were proposed and demonstrated. A hole-type organic semiconductor N,N-'-diphentyl-N,N-'-bis(1-naphthylphenyl)-1,1(')-biphenyl-4,4(')-diamine was used as emitter and collector. In the permeable-base transistors, the metal base was formed by firstly coevaporating Al and Ca in vacuum and then annealing at 120 degrees C for 5 min in air, followed by a thin Al deposition. These devices show a common-base current gain of near 1.0 and a common-emitter current gain of similar to 270.

The morphology control of pentacene for write-once-read-many-times memory devices

We realized write-once-read-many-times (WORM) memory devices based on pentacene and demonstrated that the morphology control of the vacuum deposited pentacene thin film is greatly important for achieving the unique nonvolatile memory properties. The resulted memory devices show a high ON/OFF current ratio (10(4)), long retention time (over 12 h), and good storage stability (over 240 h). The reduction of the barrier height caused by a large interface dipole and the damage of the interface dipole under a critical bias voltage have been used to explain the transition processes.

Adhesive strength of new thermal barrier coatings of rare earth zirconates

La2Zr2O7 (LZ) and La-2(Zr0.7Ce0.3)(2)O-7 (LZ7C3) as novel candidate materials for thermal barrier coatings (TBCs) were prepared by electron beam-physical vapor deposition (EB-PVD). The adhesive strength of the as-deposited LZ and LZ7C3 coatings were evaluated by transverse scratch test. Meanwhile, the factors affecting the critical load value were also investigated. The critical load value of LZ7C3 coating is larger than that of LZ coating, whereas both values of these two coatings are lower than that of the traditional coating material, i.e. 8 wt% yttria stabilized zirconia (8YSZ). The micro-cracks formed in the scratch channel can partially release the stress in the coating and then enhance the adhesive strength of the coating. The width of the scratch channel and the surface spallation after transverse scratch test are effective factors to evaluate the adhesive strength of LZ and LZ7C3 coatings.

Micropatterning of polymeric semiconductor by selective lift-off method using epoxy mold

A simple and efficient method for patterning polymeric semiconductors for applications in the field of organic electronics is proposed. The entire polymer layer, except for the desired pattern, is selectively lifted off from a flat poly(dimethylsiloxane) (PDMS) stamp surface by an epoxy mold with a relief pattern. This is advantageous because the elastic deformation of the PDMS stamp around protrusions of a patterned stamp under pressure can assist the plastic deformation of a polymer film along the pattern edges, yielding large area and high quality patterns, and the PDMS surface has low surface energy, which allows the easy removal of the polymer film.