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板条激光器谐振腔膜尺寸研究
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作者 闫连山 何学东 +1 位作者 陈学峰 张世文 《激光与红外》 CAS CSCD 北大核心 1995年第6期24-26,48,共4页
本文讨论了在高平均功率板条状激光器实际运转中由于各种因素所造成的热透镜效应及其对整个谐振腔内光场分布带来的影响,并讨论了这种影响对谐振腔输出镜的膜尺寸选择产生的具体作用,通过选取适当膜尺寸,得到较好的实验结果。
关键词 高平均功率 板条状激光器 热透镜效应 膜尺寸
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大尺寸厚膜压电陶瓷驱动变形镜的制备工艺研究 被引量:3
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作者 刘相果 胡东霞 +1 位作者 胡吉海 冯小东 《压电与声光》 CSCD 北大核心 2011年第4期570-572,577,共4页
研制了一种适合高频响应变形镜使用要求的压电陶瓷材料体系,并采用流延工艺成功制备了大尺寸厚膜(Ф90mm×0.30mm),并采用粘接固化工艺制备出Ф90mm口径的压电厚膜驱动连续变形镜。结果表明,压电陶瓷材料配方通式为Pb1-aMa[(... 研制了一种适合高频响应变形镜使用要求的压电陶瓷材料体系,并采用流延工艺成功制备了大尺寸厚膜(Ф90mm×0.30mm),并采用粘接固化工艺制备出Ф90mm口径的压电厚膜驱动连续变形镜。结果表明,压电陶瓷材料配方通式为Pb1-aMa[(Zn1-bL6)1/3Nb2(1-x)3]eZTfTigOh,e+f+g=1,M—Ca、Sr、Ba、La、K,L—Ni、Co、Fe,其机电耦合系数kp≥O.72,压电常数d33≥590pC/N,居里温度Tc≥300℃,介电损耗tanδ≤1.2%,介电常数ε33^T/ε0=2000-2500,烧成温度1150℃;扣除离焦前的压电厚膜驱动连续变形镜面形约3μm,扣除离焦后的面形约0.4μm;陶瓷厚膜的烧银过程变形致使镜面粘接工艺过程气泡难以消除,产生变形镜面-陶瓷间粘接不连续。 展开更多
关键词 尺寸压电陶瓷 流延工艺 变形镜
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束流终端大尺寸膜窗的研制 被引量:1
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作者 蒙峻 张军辉 +8 位作者 杨伟顺 罗成 杨晓天 马向利 白峰 郭迪舟 聂增森 牛志伟 楼美玲 《真空科学与技术学报》 EI CAS CSCD 北大核心 2012年第1期59-62,共4页
膜窗系统是重离子束流治癌装置中隔离大气和真空的重要系统。通过应力分析,选择高强度膜(Hostaphon)和加强纤维衬底(Kevlar)联合使用,既可以使束流通过,同时中子产额少,还可以承受大气压力。采用双层真空结构,消除膜材料的漏气效应,使... 膜窗系统是重离子束流治癌装置中隔离大气和真空的重要系统。通过应力分析,选择高强度膜(Hostaphon)和加强纤维衬底(Kevlar)联合使用,既可以使束流通过,同时中子产额少,还可以承受大气压力。采用双层真空结构,消除膜材料的漏气效应,使与膜窗相连的主系统真空度达到了10-6Pa。 展开更多
关键词 重离子治癌 尺寸 窗材料 应力分析 双层真空结构
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大尺寸金刚石膜生长中等离子体弧源的稳定性
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作者 李多生 左敦稳 +2 位作者 陈荣发 相炳坤 赵礼刚 《南京航空航天大学学报》 EI CAS CSCD 北大核心 2007年第3期338-342,共5页
保持等离子体弧源稳定性对于制备大尺寸平面金刚石膜极其重要,故从理论和实验两个方面对等离子体弧源稳定性进行了分析。研究表明,为了保持弧源的稳定,必须在生长过程中,保持稳定的电子温度和均匀的活性原子及原子基团密度。金刚石膜在... 保持等离子体弧源稳定性对于制备大尺寸平面金刚石膜极其重要,故从理论和实验两个方面对等离子体弧源稳定性进行了分析。研究表明,为了保持弧源的稳定,必须在生长过程中,保持稳定的电子温度和均匀的活性原子及原子基团密度。金刚石膜在某些条件下长时间生长时,会发生阳极环积碳现象,导致等离子体弧源扰动失稳,从而引起生长的金刚石膜含有石墨杂质。通过预处理阳极环、控制碳源、加大氢气量等措施可保持弧源稳定。在此条件下生长金刚石膜,经SEM,Raman分析表明,其晶粒均匀、晶界清晰,仅有金刚石特征峰出现。 展开更多
关键词 等离子体 尺寸平面金刚石 化学气相沉积 弧源稳定性
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不同膜胞尺寸铝多孔氧化膜的制备
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作者 郭敏 《腐蚀与防护》 CAS 北大核心 2011年第9期701-703,共3页
采用在磷酸及草酸溶液中加入添加剂的方法制备了铝多孔氧化膜,借助扫描电镜分析了多孔氧化膜的微观结构,讨论了不同组成电解质溶液对铝多孔氧化膜膜胞尺寸的影响。结果表明,通过在磷酸和草酸溶液中添加少量添加剂,可以在60~500 V的氧... 采用在磷酸及草酸溶液中加入添加剂的方法制备了铝多孔氧化膜,借助扫描电镜分析了多孔氧化膜的微观结构,讨论了不同组成电解质溶液对铝多孔氧化膜膜胞尺寸的影响。结果表明,通过在磷酸和草酸溶液中添加少量添加剂,可以在60~500 V的氧化电压内获得多孔氧化膜。得到膜胞尺寸最大可达1.3μm;膜胞尺寸随着氧化电压的升高呈线性升高趋势。 展开更多
关键词 多孔氧化 阳极氧化 尺寸
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大尺寸厚膜电路陶瓷基片走俏市场
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《新材料产业》 2001年第1期36-36,共1页
横店集团电子陶瓷有限公司不断加大科技投入力度,使公司生产规模、产品档次得到快速提升。到目前为止,该公司生产的高压聚焦片产品已占据国内市场主要份额,并且已打入国际市场。2000年5月,该公司已具备4in×4in、4.5in×4.5in。
关键词 横店集团电子陶瓷有限公司 尺寸电路 陶瓷基片 激光加工系统 表面光洁度
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γ射线辐射对尼龙6复合薄膜性能的影响 被引量:1
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作者 杨明成 朱军 +3 位作者 陈海军 刘克波 赵惠东 张传国 《辐射研究与辐射工艺学报》 EI CAS CSCD 北大核心 2005年第1期62-64,共3页
用 Co γ 射线对尼龙 6 复合薄膜(五层共挤出复合薄膜,尼龙 6/粘接聚乙烯/聚乙烯/粘接聚乙烯/尼龙 6) 60进行辐射改性。研究了辐照剂量对材料性能的影响。结果表明,在 10—50kGy 的剂量范围内,尼龙 6 复合薄膜的机械性能大为提高... 用 Co γ 射线对尼龙 6 复合薄膜(五层共挤出复合薄膜,尼龙 6/粘接聚乙烯/聚乙烯/粘接聚乙烯/尼龙 6) 60进行辐射改性。研究了辐照剂量对材料性能的影响。结果表明,在 10—50kGy 的剂量范围内,尼龙 6 复合薄膜的机械性能大为提高,收缩率明显减小,尺寸稳定性明显提高,同时,仍保持其原有的良好阻隔性能。 展开更多
关键词 辐射改性 尼龙6复合 尺寸稳定性
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8×8阵列压电厚膜驱动变形镜的制备及性能研究
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作者 刘相果 胡东霞 +1 位作者 冯小东 曾祥明 《压电与声光》 CSCD 北大核心 2013年第1期66-69,共4页
利用流延工艺制备大尺寸高性能压电陶瓷片(100mm×100mm×0.50mm),在此基础上研究8×8阵列排布的厚膜压电陶瓷驱动连续变形镜的制备工艺技术,并对变形镜的理论拟合面形和实际闭环控制校正面形进行研究分析。结果表明,变形... 利用流延工艺制备大尺寸高性能压电陶瓷片(100mm×100mm×0.50mm),在此基础上研究8×8阵列排布的厚膜压电陶瓷驱动连续变形镜的制备工艺技术,并对变形镜的理论拟合面形和实际闭环控制校正面形进行研究分析。结果表明,变形镜的初始面形的像差振幅为2.664λ,像差均方根振幅为0.557λ,而经闭环控制校正+手动微校正后后,获得较佳的镜面效果像差振幅为0.36λ,像差均方根振幅为0.095λ;闭环控制校正面形与理论拟合的面形(像差振幅为0.005λ,像差均方根振幅为0)存在一定差距,主要原因是变形镜制备工艺过程或驱动闭环控制系统存在一定的滞后性或试验误差造成的。 展开更多
关键词 尺寸压电陶瓷 流延工艺 变形镜 闭环控制
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膜特征对锂资源提取过程的影响 被引量:6
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作者 李志录 王敏 +2 位作者 赵有璟 彭正军 白露 《化工进展》 EI CAS CSCD 北大核心 2021年第9期5061-5072,共12页
可再生能源领域的发展吸引了众多学者对锂电池行业的关注,高效绿色提锂技术成为研究的重点。膜分离技术由于在连续操作中具有操作方便、运行易控、耗能低等特点在锂资源提取中展现出广阔的应用前景。本文基于锂资源提取的膜分离技术,归... 可再生能源领域的发展吸引了众多学者对锂电池行业的关注,高效绿色提锂技术成为研究的重点。膜分离技术由于在连续操作中具有操作方便、运行易控、耗能低等特点在锂资源提取中展现出广阔的应用前景。本文基于锂资源提取的膜分离技术,归纳并讨论膜孔和膜表面特征对锂离子分离的影响。文章指出,离子在膜孔中的传输是其分离的基础,离子尺寸和离子在膜孔中传输形态影响其传输速率。膜孔的尺寸和形态是影响锂离子分离的关键因素,不同尺寸、形态和膜孔内电荷在分离过程中表现出不同的分离效果。基于膜表面特征,文章概括了现有荷正电膜、荷负电膜及表面亲疏水性在锂离子分离中的性能差异。最后,文章探究了膜分离技术在锂资源提取中存在的挑战和机遇,推进膜分离技术在锂资源提取方向的理论研究和实际应用。 展开更多
关键词 锂资源提取 分离技术 尺寸和形态 表面电荷和亲疏水性 纳滤
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气体分离用PI/TiO_2纳米复合膜的制备
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作者 杜宏伟 孔瑛 《应用化学》 CAS CSCD 北大核心 2003年第5期462-465,共4页
通过溶胶 凝胶法制备了气体分离用PI/TiO2 纳米复合膜材料。采用FT IR、SEM、TEM、UV Vis、耐化学介质性能和气体透气性能测试对膜材料的结构和性能进行了表征。结果表明 ,复合膜中TiO2 与PI两相在空间上结合紧密。含TiO2 质量分数为 2 ... 通过溶胶 凝胶法制备了气体分离用PI/TiO2 纳米复合膜材料。采用FT IR、SEM、TEM、UV Vis、耐化学介质性能和气体透气性能测试对膜材料的结构和性能进行了表征。结果表明 ,复合膜中TiO2 与PI两相在空间上结合紧密。含TiO2 质量分数为 2 2 3 %的复合膜中TiO2 颗粒尺寸为 1 0nm左右 ;含TiO2 质量分数为 2 7 2 %时 ,复合膜仍光学透明。复合材料的UV Vis吸收表现出了量子尺寸效应。与纯PI膜相比 ,复合膜的耐化学介质性能和透气性能显著增强。当TiO2 质量分数为 2 2 3 %时 ,复合膜的透H2 系数从纯PI膜的 2 85 7× 1 0 -15m3 ·m/(m2 ·s·Pa)增加到 1 0 61×1 0 -14 m3 ·m/(m2 ·s·Pa) ,H2 /N2 和H2 /CH4理想分离系数分别为 1 87 5和 1 43 2。 展开更多
关键词 纳米复合 聚酰亚胺/TiO2 量子尺寸效应 气体分离
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兰州重离子加速器深层治癌束流线真空系统 被引量:4
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作者 杨晓天 张军辉 +7 位作者 蒙峻 张喜平 杨伟顺 郭宗辉 郭迪舟 赵玉刚 胡振军 侯生军 《真空科学与技术学报》 EI CAS CSCD 北大核心 2009年第S1期46-50,共5页
重离子深层治癌束流线从兰州重离子加速器冷却储存环(HIRFL-CSR)主环引出,利用能量为100MeV/u~430MeV/ u的碳离子束,开展治疗体内各种癌症的深层治癌研究。该束流线真空系统包括极高真空段、超高真空段和大气段,采用不同的真空获得方... 重离子深层治癌束流线从兰州重离子加速器冷却储存环(HIRFL-CSR)主环引出,利用能量为100MeV/u~430MeV/ u的碳离子束,开展治疗体内各种癌症的深层治癌研究。该束流线真空系统包括极高真空段、超高真空段和大气段,采用不同的真空获得方案和工艺路线,分别在极高真空段和超高真空段获得了8×10^(-10)Pa和1×10^(-6)Pa的真空度,并顺利实现了束流线的真空过渡,保证了HIRFL-CSR主环极高真空系统的安全运行;研制了适用于高频率扫描磁铁内放置的真空管道,消除了涡流对束流的影响;对隔离真空和大气的大尺寸膜窗材料进行了调研,选择高强度塑料膜(Hostaphan)和加强纤维膜(Kevlar)联合使用,既能让束流通过,又不会产生危害人体的中子,并能够有足够的强度抵御大气压力。该束流线真空系统的建成为重离子深层治癌的研究提供了良好的真空条件。 展开更多
关键词 重离子加速器 重离子束治癌 超高/极高真空系统 涡流 尺寸
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镀金焊盘酸蚀缺损探讨
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作者 幸锐敏 缪桦 《电镀与精饰》 CAS 北大核心 2018年第4期28-32,46,共6页
PCB板内表面涂覆为"电金+化金"是比较新颖的工艺,但在生产过程中发现有镀金焊盘缺损的问题。本文通过分析不同金镍厚组合的镀金焊盘在酸蚀中的抗蚀能力,得出金厚达到一定厚度时,致密的金层会成为阴极性镀层,加速蚀刻作为阳极... PCB板内表面涂覆为"电金+化金"是比较新颖的工艺,但在生产过程中发现有镀金焊盘缺损的问题。本文通过分析不同金镍厚组合的镀金焊盘在酸蚀中的抗蚀能力,得出金厚达到一定厚度时,致密的金层会成为阴极性镀层,加速蚀刻作为阳极性镀层的镍层,其速度至少加快2倍。利用这一规律,重新定义了合理的金厚范围,优化了酸蚀中保护镀金盘的干膜尺寸。 展开更多
关键词 镀金盘 焊盘缺损 阴极性镀层 膜尺寸
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Proton-exchange Sulfonated Poly(ether ether ketone)/Sulfonated Phenolphthalein Poly(ether sulfone) Blend Membranes in DMFCs 被引量:3
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作者 高启君 王宇新 +2 位作者 许莉 王志涛 卫国强 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第6期934-941,共8页
A sulfonated poly(ether ether ketone) (SPEEK) membrane with fairly high degree of sulfonation (DS) swells excessively and even dissolves at high temperature. To solve these problems, sulfonated phenolphthalein p... A sulfonated poly(ether ether ketone) (SPEEK) membrane with fairly high degree of sulfonation (DS) swells excessively and even dissolves at high temperature. To solve these problems, sulfonated phenolphthalein poly(ether sulfone) (SPES-C, DS= 53.7%) is blended with the SPEEK matrix (DS= 55.1%, 61.7%) to prepare SPEEKJSPES-C blend membrane. The decrease in swelling degree and methanol permeability of the membrane is dose-dependent. Pure SPEEK (DS = 61.7%) membrane dissolves completely in water at 70℃, whereas the swelling degree of the SPEEK (DS = 61.7%)/SPES-C (40%, by mass) membrane is 29.7% at 80℃. From room temperature to 80℃, the methanol permeability of all SPEEK (DS = 55.1%)/SPES-C blend membranes is about one order of magnitude lower than that of Nafion 115. At higher temperature, the addition of SPES-C polymer increases the dimensional stability and greater proton conductivity can be achieved. The SPEEK (DS = 55.1%)/SPES-C (40%, by mass) membrane can withstand temperatures up to 150℃. The proton conductivity of SPEEK (DS = 55.1%)/SPES-C (30%, by mass) membrane approaches 0.16 S·cm^-1, matching that of Nafion 115 at 140℃ and 100% RH, while pure SPEEK (DS = 55.1%) membrane dissolves at 90℃. The SPEEK/SPES-C blend membranes are promising for use in direct methanol fuel cells because of their good dimensional stability, high proton conductivity, and low methanol permeability. 展开更多
关键词 sulfonated poly(ether ether ketone) sulfonated phenolphthalein poly(ether sulfone) blend membrane direct methanol fuel cell
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THEORETICAL EFFECTS OF MOLECULAR DIMENSION AND CONFIGURATION ON EFFECTIVE DIFFUSION COEFFICIENT OF MACROMOLECULES IN MICROPOROUS MEMBRANES 被引量:1
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作者 何志敏 《Transactions of Tianjin University》 EI CAS 1995年第1期47+42-47,共7页
This paper presents a theoretical method for predicting the effective diffusion coefficient of macromolecules in the microporous membrfines in view of the effects of molecular dimension and configuration. On the basi... This paper presents a theoretical method for predicting the effective diffusion coefficient of macromolecules in the microporous membrfines in view of the effects of molecular dimension and configuration. On the basis of the hindered diffusion theory of spherical neutral macromolecules in a micropore of a long cylinder, the effects of molecular dimension and configuration are studied by defining two molecular dimensions:the mean projected radius to predict the concentration partition and the ' hydrodynamically equivalent sphere' radius to evaluate the hydrodynamic reverse drag force. The quantitative comparison shows that the effective diffusion coefficients for different macromolecules predicted by the present method are more consistent with the available published experimental data. 展开更多
关键词 effective diffusion coefficient microporous membrane molecular size molecular configuration
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Effect of Zn/Mg ratio on cathodic protection of carbon steel using Al-Zn-Mg sacrificial anodes 被引量:8
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作者 Mosaad SADAWY Saad SAAD Randa ABDEL-KARIM 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第8期2067-2078,共12页
Al-Zn-Mg alloys with different Zn/Mg mass ratios were evaluated as sacrificial anodes for cathodic protection of carbon steel in 3.5 wt.%Na Cl solution.The anodes were fabricated from pure Al,Zn and Mg metals using ca... Al-Zn-Mg alloys with different Zn/Mg mass ratios were evaluated as sacrificial anodes for cathodic protection of carbon steel in 3.5 wt.%Na Cl solution.The anodes were fabricated from pure Al,Zn and Mg metals using casting technique.Optical microscopy,SEM-EDS,XRD and electrochemical techniques were used.The results indicated that with decreasing Zn/Mg mass ratio,the grain size ofα(Al)and the particle size of the precipitates decreased while the volume fraction of the precipitates increased.The anode with Zn/Mg mass ratio>4.0 exhibited the lowest corrosion rate,while the anode with Zn/Mg mass ratio<0.62 gave the highest corrosion rate and provided the highest cathodic protection efficiency for carbon steel(AISI 1018).Furthermore,the results showed that the anode with Zn/Mg mass ratio<0.62 exhibited a porous corrosion product compared to the other anodes. 展开更多
关键词 cathodic protection Al-Zn-Mg sacrificial anode current capacity passive film PRECIPITATE grain size
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Modeling investigation of geometric size effect on pervaporation dehydration through scaled-up hollow fiber NaA zeolite membranes 被引量:4
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作者 Jiacheng Wang Peng Ye +2 位作者 Xuechao Gao Yuting Zhang Xuehong Gu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第7期1477-1484,共8页
A mass transfer model in consideration of multi-layer resistances through NaA zeolite membrane and lumen pressure drop in the permeate side was developed to describe pervaporation dehydration through scaled-up hollow ... A mass transfer model in consideration of multi-layer resistances through NaA zeolite membrane and lumen pressure drop in the permeate side was developed to describe pervaporation dehydration through scaled-up hollow fiber supported NaA zeolite membrane. It was found that the transfer resistance in the lumen of the permeate side is strongly related with geometric size of hollow fiber zeolite membrane, which could not he neglected. The effect of geometric size on pervaporation dehydration could be more significant under higher vacuum pressure in the permeate side. The transfer resistance in the lumen increases with the hollow fiber length but decreases with lumen diameter. The geometric structure could be optimized in terms of the ratio of lumen diameter to membrane length. A critical value of d1/L (Rc) to achieve high permeation flux was empirically correlated with extraction pressure in the permeate side. Typically, for a hollow fiber supported NaA zeolite membrane with length of 0.40 m, the lumen diameter should be larger than 2.0 mm under the extraction pressure of 1500 Pa. 展开更多
关键词 PERVAPORATION NaA zeolite membrane Hollow fiber Lumen pressure drop Geometric parameters
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Quantum size effects in InP inner film fiber
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作者 WANG Ting-yun WANG Ke-xin LU Jun 《Optoelectronics Letters》 EI 2005年第1期17-20,共4页
Based on the semiconductor amplifiing properties and the structure of optical fiber wave guide an InP inner fiber is developed.The InP inner film fiber can be employed as a small size,broadband,and ultra-short fiber a... Based on the semiconductor amplifiing properties and the structure of optical fiber wave guide an InP inner fiber is developed.The InP inner film fiber can be employed as a small size,broadband,and ultra-short fiber amplifier. The quantum size effects of the fiber are emphatically investigated in the work. Using the experimental data,we compare the effective mass approximation (EMA) with effective pararneterization within the tight binding (EPTB) models for the accurate description of the quantum size effects in InP. The results show that the EPTB model provides an excellent description of band gap variation over a wide range of sizes. The Bohr diameter and the effective Rydberg energy of InP are calculated. Finally,the amplifiing properties of the InP inner film fiber are discussed due to the quantum size effects. 展开更多
关键词 光纤 量子尺寸 半导体 EPTB模型
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Dependence of Optical Absorption in Silicon Nanostructures on Size of Silicon Nanoparticles
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作者 丁文革 苑静 +3 位作者 孟令海 武树杰 于威 傅广生 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第4期688-692,共5页
The amorphous silicon nanoparticles (Si NPs) embedded in silicon nitride (SiNx) films prepared by helicon wave plasma-enhanced chemical vapor deposition (HWP-CVD) technique are studied. From Raman scattering inv... The amorphous silicon nanoparticles (Si NPs) embedded in silicon nitride (SiNx) films prepared by helicon wave plasma-enhanced chemical vapor deposition (HWP-CVD) technique are studied. From Raman scattering investigation, we determine that the deposited film has the structure of silicon nanocrystals embedded in silicon nitride (nc-Si/SiNx) thin film at a certain hydrogen dilution amount. The analysis of optical absorption spectra implies that the Si NPs is affected by quantum size effects and has the nature of an indirect-band-gap semiconductor. Further, considering the effects of the mean Si NP size and their dispersion on oscillator strength, and quantum-confinement, we obtain an analytical expression for the spectral absorbance of ensemble samples. Gaussian as well as lognormal size-distributions of the Si NPs are considered for optical absorption coefficient calculations. The influence of the particle size-distribution on the optical absorption spectra was systematically studied. We present the fitting of the optical absorption experimental data with our model and discuss the results. 展开更多
关键词 optical absorption silicon nanoparticles quantum size effects oscillator strength silicon nitride film
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The Analysis of Nano-Size Inhomogeneities of Substrate by Surface Electrons over Superfluid Helium Film
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作者 Yaroslav Yurievich Bezsmolnyy Victor Alekseevich Nikolaenko Svjatoslav Sergeevich Sokolov 《Journal of Physical Science and Application》 2016年第5期37-41,共5页
The surface quality of the substrate is a crucial factor in building "clean" quantum-dimensional systems. There are a number of micro-nano metric methods for the analysis state of surface: the atomic force microsco... The surface quality of the substrate is a crucial factor in building "clean" quantum-dimensional systems. There are a number of micro-nano metric methods for the analysis state of surface: the atomic force microscopy, the scanning tunneling microscopy and others. The SE (surface electron) over substrate has a "soft" hydrogen-like spectrum in the normal direction and the SEs mobility along is sensitive to the inhomogeneities of the substrate and this is analyzed in work. The values of electron mobility and energy of thermal activation are basic parameters of transport process which essentially depend on the helium film thickness. For analysis of nano-size inhomogeneities of substrate here we apply a new method providing a uniformity of the film thickness on substrate and fixing of measuring cell with supply wires. The plunger with electro-mechanic driver into a hermetic chamber is used for variation the helium level and consequently the film thickness. Considering values the conductivity and the variation of potential along surface is estimated the effective size of roughness from several nanometers (for non-saturated helium film) to 10^2 nm (for saturated film). 展开更多
关键词 Liquid helium surface electron low-dimensional systems nano-technology.
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Vibration Response Characteristics against the Radial and Axial Shocks on Small Size Hard Disk Drive Spindle Supported by Oil Film Bearings
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作者 Masayuki Ochiai Yuta Sunami Hiromu Hashimoto 《Journal of Mechanics Engineering and Automation》 2014年第7期547-554,共8页
This paper describes the experimental study on shock response of FDB (fluid dynamic bearing) spindle for HDDs (hard disk drives). The FDBs are widely used as rotating shaft support elements for HDD spindle motors.... This paper describes the experimental study on shock response of FDB (fluid dynamic bearing) spindle for HDDs (hard disk drives). The FDBs are widely used as rotating shaft support elements for HDD spindle motors. Recently, the opportunity for the HDD spindle motors exposed to external vibration has been increasing because the HDDs are used for various information related equipment such as mobile PCs (personal computers), video cameras, car navigation systems and so on. Hence, the rotating shaft has a possibility to come in contact with the bearing by external shocks and it causes wear or seizure to the bearing surface. To avoid the problem, it is extremely important to know how the spindle moves against the large shock on HDDs experimentally. However, as far as the authors know, there are few experimental studies treating the shock response of HDD spindles. In this paper, firstly, we propose a new test rig and experimental method for shock response of FDB spindles. Then the shock tests against the radial and axial disturbance on FDB spindle for 2.5" HDD are conducted. Finally, the experimental results of shock response waveforms and maximum displacement of disk are shown. 展开更多
关键词 TRIBOLOGY fluid film bearing hard disk drive spindle motor shock test shock response
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