Prototype High Angular Resolution LEKIDs for NIKA2

We report on Raman spectroscopy, temperature-dependent in-plane resistivity, and in-plane magnetoresistance experiments in highly oriented pyrolytic graphite (HOPG) implanted with As and Mn. A pristine sample was also studied for comparison. Two different fluences were applied, \(\varphi = 0.5\times 10^{16}\,\, {\hbox {ions}}/{\hbox {cm}}^{2}\) and \(\varphi = 1.0\times 10^{16}\,\,{\hbox {ions}}/{\hbox {cm}}^{2}\). The implantations were carried out with 20 keV ion energy at room temperature. The Raman spectroscopy results reveal the occurrence of drastic changes of the HOPG surface as a consequence of the damage caused by ionic implantation. For the higher dose, the complete amorphization limit is attained. The resistivity and magnetoresistance results were obtained placing electrical contacts on the irradiated sample surface. Owing to the strong anisotropy of HOPG, the electrical current propagates mostly near the implanted surface. Shubnikov–de Haas (SdH) oscillations were observed in the magnetoresistance at low temperatures. These results allow the extraction of the fundamental SdH frequencies and the carriers’ effective masses. In general, the resistivity and magnetoresistance results are consistent with those obtained from Raman measurements. However, one must consider that the electrical conduction in our samples occurs as in a parallel association of a largely resistive thin sheet at the surface strongly modified by disorder with a thicker layer where damage produced by implantation is less severe. The SdH oscillations do not hint to significant changes in the carrier density of HOPG.     

Teaching Students to Document a Design Project and Present the Results

Knowing and being able to apply the design process are important to the practicing engineer. Being able to thoroughly document the design process and present the results effectively are skills that employers and clients expect engineers to possess. Students have an opportunity to learn and practice the design process throughout their engineering studies. While they are often asked to document their design projects and present the results, they rarely receive instruction on how to do so effectively. At The Ohio State University, in courses developed as part of the National Science Foundation (NSF)-sponsored Gateway Engineering Education Coalition, students are taught to document their design projects and present the results in a professional manner. They produce a variety of documents including laboratory notebooks, a design schedule, progress reports, and a final report. In addition, they make an oral presentation on the project. Instruction on producing a particular document is provided when students are ready to begin work on that document. This paper outlines the instruction on documentation provided at each stage of the design process and discusses evaluation of the documents prepared by the students.     

Latest Results on Complex Plasmas with the PK-3 Plus Laboratory on Board the International Space Station

Complex plasmas are low temperature plasmas that contain microparticles in addition to ions, electrons, and neutral particles. The microparticles acquire high charges, interact with each other and can be considered as model particles for effects in classical condensed matter systems, such as crystallization and fluid dynamics. In contrast to atoms in ordinary systems, their movement can be traced on the most basic level, that of individual particles. In order to avoid disturbances caused by gravity, experiments on complex plasmas are often performed under microgravity conditions. The PK-3 Plus Laboratory was operated on board the International Space Station from 2006 – 2013. Its heart consisted of a capacitively coupled radio-frequency plasma chamber. Microparticles were inserted into the low-temperature plasma, forming large, homogeneous complex plasma clouds. Here, we review the results obtained with recent analyzes of PK-3 Plus data: We study the formation of crystallization fronts, as well as the microparticle motion in, and structure of crystalline complex plasmas. We investigate fluid effects such as wave transmission across an interface, and the development of the energy spectra during the onset of turbulent microparticle movement. We explore how abnormal particles move through, and how macroscopic spheres interact with the microparticle cloud. These examples demonstrate the versatility of the PK-3 Plus Laboratory.     

Pool Boiling in Microgravity: Recent Results and Perspectives for the Project DEPA-SJ10

Two research projects on pool boiling in microgravity have been conducted aboard the Chinese recoverable satellites. Ground-based experiments have also been performed both in normal gravity and in short-term microgravity in the Drop Tower Beijing. Steady boiling of R113 on thin platinum wires was studied with a temperature-controlled heating method, while quasi-steady boiling of FC-72 on a plane plate was investigated with an exponentially increasing heating voltage. In the first case, slight enhancement of heat transfer is observed in microgravity, while diminution is evident for high heat flux in the second one. Lateral motions of bubbles on the heaters are observed before their departure in microgravity. The surface oscillation of the merged bubbles due to lateral coalescence between adjacent bubbles drives it to detach from the heaters. The Marangoni effect on the bubble behavior is also discussed. The perspectives for a new project DEPA-SJ10, which has been planned to be flown aboard the Chinese recoverable satellite SJ-10 in the future, are also presented.     

TiO_2纳米薄膜光催化剂制备技术的新进展

综述了TiO_2纳米薄膜光催化剂制备方法的最新进展,讨论了传统技术的新发展如改进的溶胶-凝胶法和微波辅助沉积法,同时也详述了水热溶剂热法、原位生长法及自组装法等新型制备技术,最后提出了TiO_2纳米薄膜制备技术今后的发展方向.     

P型透明导电SnO2薄膜的研究进展

SnO2薄膜是一种应用广泛的宽禁带半导体材料.近几年来,随着对SnO2的光电性质及其在光电器件方面应用的开发研究,SnO2薄膜成为研究热点之一.制备掺杂的p型SnO2是形成同质p-n结以及实现其实际应用的重要途径.近年来,国内外在p型SnO2薄膜研究方面取得了较大的进展.目前报道的p型SnO2薄膜的最高电导率为5.952Ω-1cm-1.并且得到了具有较好非线性伏安特性的铟锡氧化物的透明p-n结.本文就其最新进展进行了综述.     

现代破碎原理及国外新型破碎机

介绍了几种国外最为著名的几家破碎设备制造厂推出的最新型破碎机——HP系列圆锥破碎机、立式冲击破碎机和超强力反击破碎机.这些新机型突破了传统的破碎方式,机器构造及破碎腔形应用了最新的研究成果,具有较为优良的综合使用性能,代表了目前世界破碎设备制造业最为先进的水平.     

纳米TiO2光催化剂可见光化的最新进展

TiO2是当前最具应用潜力的光催化剂之一，但仍然存在不足，主要表现在光吸收波长狭窄，吸收波长阈值在紫外区，摘要利用太阳光能量比例低等方面。对其进行改性，增加其光吸收波长范围，可以更充分地利用太阳光，达到节约能源的目的。因此，TiO2可见光化一直是研究热点。综述了近几年国内外最新的纳米TiO2可见光化改性的进展，如金属或非金属离子掺杂、贵金属沉积、有机染料光敏化、溶剂热法制备等，并对TiO2光催化剂的应用前景进行了展望，认为溶剂热法简便易行，应该重视和大力研究。     

SnO_2复合薄膜甲烷气敏传感器研究进展

甲烷是具有稳定四面体分子结构的碳氢化合物,其键能大、分解困难且活性低,是煤矿安全生产的主要障碍及一种温室气体。SnO2半导体薄膜制备工艺简单、成本低廉、性能稳定,是甲烷传感器研发的主流气敏材料。科技人员进行了很多相关研究以提高传感器的性能,如新气敏材料的研究、催化剂/添加剂的使用、气敏机理的探索、传感器结构改进及气敏膜的表面修饰改性等。本文从气敏膜制备与改性、传感器结构设计及气敏机理研究三个方面,综述了近年来SnO2复合薄膜甲烷传感器的研究进展,结果表明:①应开发复合型金属氧化物半导体及高分子气敏材料,以提高灵敏度、选择性与稳定性;②研发微型智能传感器是未来发展的主要方向,而自组装技术应可用于制备金属氧化物半导体薄膜气体传感器微纳阵列;③气敏机理应与实验测试、材料设计及器件制备进行对照研究。     

Latest results from the EDELWEISS WIMP search

The latest results obtained by the EDELWEISS Weakly Interacting Massive Particles (WIMP) direct detection experiment using three heat-and-ionization 320 g germanium bolometers are presented. Presently, the most sensitive WIMP direct detection experiment for WIMP mass >30 GeV, EDELWEISS-I is testing a range of SUSY models compatible with the accelerator constraints. The status and main characteristics of EDELWEISS-II, involving in a first stage 28 germanium bolometers, and able to accommodate up to 120 detectors, will be briefly presented.     

固载型金属纳米催化剂的最新研究进展

在金属催化有机合成反应中,金属催化剂被制备成微细颗粒以提高其催化接触面积,与此同时,对其进行负载以解决分离回收困难的问题。综述了近几年固载型金属纳米催化剂的研究进展,总结了多种材料在各种金属纳米催化剂负载方面的应用及优越性。     

微叠层结构材料的研究现状

本文论述了微叠层材料性能优越于单体材料的原因 :该材料的层间距较小 ,限制了位错的移动和缺陷的尺寸。微叠层材料制备方法有多种 ,磁控溅射是制备纳米级微叠层材料的有效方法。Hall Petch理论 ,Orowan变形理论 ,多微粒模型等是计算层间应力的较好的理论。本文也提出了目前有发展前途的几种微叠层材料 ,并认为制备纳米级微叠层材料、研究其断裂和脱层机理、增韧机理是该材料领域的重要研究方向     

位置灵敏原子探针的新发展与新应用

本文介绍位置灵敏原子探针显微分析实验手段的最新发展、应用与前景。以应用这种技术研究不锈钢与化合物半导体为例，结合实验结果介绍新的图像显示方法。此外还示例概述了位置灵敏原子探针在钢与合金研究中的新应用。最后，作者对世界上三维原子探针的发展前景作了展望。     

电离规的新进展

介绍了传统热阴极电离规和冷阴极电离规的发展历程和研究现状、新型场发射阴极(微尖型阴极和碳纳米管阴极)在电离规中的应用、小型化电离规的发展和国内在超高/极高真空电离规研究方面取得的成果和现状。重点回顾了碳纳米管阴极电离规和小型化电离规在近年来取得的重大成就。由于碳纳米管具有长径比大、曲率半径小、机械特性强、导电性好和优异的场发射特性,使得其作为电离规阴极有望解决传统冷阴极电离规在低压下不能放电的困难和传统热阴极电离规的热出气效应,从而为极高真空测量提供一种解决途径。     

静电型微继电器的设计与研究

静电型微继电器采用静电致动原理,以静电力作为触点吸合的驱动力。在分析纵向静电型微继电器工作原理和Pull-in模型的基础上,给出了当前国内外典型的静电型继电器结构,阐述了这些微继电器的技术特点、制造工艺及其主要性能参数。对静电型继电器触点的材料选取及其性能进行比较分析。分析了静电型继电器实用化存在的主要技术难题和进一步研究可能的方向。     

钙钛矿太阳能电池技术发展历史与现状

简要回顾了钙钛矿太阳能电池的发展历史,解释了钙钛矿太阳能电池本质上是固态染料敏化太阳能电池。介绍了钙钛矿太阳能电池的微观发电机理,结合钙钛矿太阳能电池的能级图分析讨论了钙钛矿与电子传输层和空穴传输层的能级匹配。分析总结了钙钛矿太阳能电池的光伏技术参数,包括光生电流密度、开路电压、填充因子、能量转换效率以及光伏性能的稳定性。钙钛矿太阳能电池的能量转换效率、短路电流密度和开路电压均已超过非晶硅薄膜太阳能电池,填充因子与非晶硅薄膜太阳能电池很接近。钙钛矿太阳能电池有希望实现产业化而成为下一代薄膜太阳能电池。指出了钙钛矿太阳能电池大规模市场应用在制造技术上的瓶颈即空穴传输层的造价昂贵,并综述了解决该瓶颈的最新研究工作。