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It has been demonstrated that ellipsometry can be used to study the kinetic properties of organic materials deposited, under vacuum, as thin films on optical surfaces. The organic films were deposited in a controlled manner using a vapor effusion source. Evaporation rate measurements on a DC-704 silicone oil film over a thickness range of 140 to 10 Å have shown that the film exists as two distinct layers with a transition thickness of ~18 Å. The second layer (d > 18 Å) exhibits an linear evaporation rate corresponding to that of the bulk fluid at 300 K while the first layer has a value two orders of magnitude smaller. The first layer was interpreted as a single monolayer having a thickness equal to the helix diameter of the silicone molecule. Additional measured kinetic properties were the sticking coefficients and vapor pressure tor various substrate temperatures and the molecular binding energy. The measured values of Δ and ψ were used to determine the optical constants of both DC-704 and DC-705 silicone oil films as N = 1.5 l — i0.00 and 1.48 — i0.00, respectively, where N = n — ik. 相似文献
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Helmut Schwarz 《Zeitschrift für Physik A Hadrons and Nuclei》1961,162(4):402-409
The temperature coefficients (TCR) of vacuum-deposited thin-metal-film resistors were measured in vacuum, air, argon, and silicone oil, and different characteristics were obtained. The resistors were made by evaporating a nickel-chrome alloy (Nichrome 80 to 20) in vacuum onto ceramic substrates to produce a 500-ohms-persquare film. Measurements were made of films which were uncoated and of films which were coated with a protection layer of silicone monoxide in thicknesses from 5000 to 10000 å. When measured under vacuum, the resistors displayed a TCR which was lower than that obtained in air, argon, or silicone oil. In an argon environment, the resistors had lower TCR characteristics than they had in air or silicone oil. Even when the resistor films were protected by a 10000-å-thick layer of silicone monoxide, their TCR behavior differed in different gas environments. Most of the TCR's measured in the temperature range from ?55Ω to +150Ω C were between 5 and 50 parts per million per degree centigrade. 相似文献
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研究了沉积在液体基底(硅油)表面金薄膜中的带状有序结构和自组装现象.实验结果表明:在一定条件下,生长在硅油表面的金薄膜中可形成一种特征的有序结构,它是由近似矩形状的畴块拼接而成的;相邻畴块的长度近似相等,但宽度一般不同,因而具有特征长度为101—102μm数量级的准周期结构.进一步的实验发现:此类带状有序结构是由薄膜中特征内应力所引起的物质相互挤压而形成的.另外,对此类具有近似自由支撑边界条件的薄膜中的内应力形成机理进行了研究.
关键词:
薄膜
有序结构
内应力
自组装 相似文献
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水上溢油光谱作为高光谱遥感目标识别与分类的参考依据,在溢油识别与厚度区分等方面具有重要的研究意义。通过测量厚度范围为1.0~127 μm间的轻柴油的20组光谱曲线,计算其反射率光谱曲线随厚度变化的特征,并利用db4小波对反射率数据进行处理,突出光谱奇异性及其位置与奇异值随油膜厚度变化的特征。在研究范围内的油膜光谱反射率高于水体,但反射率值与油膜厚度间无固定增减关系。在其厚度小于6 μm时反射率光谱曲线无明显特征,厚度大于6 μm后在388 nm附近存在区别于水体的反射峰特征且随厚度增加特征愈加突出。油膜光谱小波分析后的细节系数在388~393 nm内表现出明显的奇异性,并且奇异位置随厚度增加向短波方向移动、奇异极值增大。研究证实了小波分析在确定油膜光谱特征位置与变化研究中的积极作用,并发现了紫外-可见光短波范围内的光谱特征,为紫外遥感进行溢油识别提供了科学依据。 相似文献
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A characteristic wedge-shaped iron (Fe) film system, deposited on glass substrates by a DC-magnetron sputtering method and quenched by silicone oil during deposition, has been successfully fabricated. Telephone cord buckles induced by residual compressive stress can be widely observed in the samples. They are shown to nucleate and grow slowly in the atmosphere, but propagate rapidly after disturbance of the film by an external force. Various buckling phenomena, such as generation of disordered telephone cord networks on a isotropic substrate, formation of parallel wavy buckle and circular blister lines on a patterned substrate, partial healing of buckling by pushing the film back to the substrate during the propagation process, occurrence of straight-sided blisters near a step edge, are present in this paper. 相似文献
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Marangoni forces created by surface plasmon decay 总被引:1,自引:0,他引:1
We present optical microfluidic manipulation of silicone oil and glycerol via surface tension driven forces sustained by surface plasmon deexcitation energy. The phonon energy associated with the decaying optically excited surface plasmons in a thin gold foil creates thermal gradients capable of actuating fluid flows. Spectral dependence of the plasmon decay length and control of optical beam characteristics are shown to provide a means for further manipulation. 相似文献
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研究水表薄油膜厚度与其反射率光谱之间的变化规律,对于分析海洋油膜污染和油气勘探的遥感探测机理具有十分重要的意义。建立了水面薄油膜厚度的生物光学模型,并介绍了单波段和双波段比值简化算法反演薄油膜厚度信息的方法。通过对原油样品进行油膜厚度定量反演,研究了遥感反射率随水表油膜厚度的变化规律。研究发现,可见光到近红外波段(450~800nm)反射率对油膜厚度变化最为敏感,有很高的负相关关系,并且随着油膜厚度的增加呈负指数形态下降。对于浅水环境较混浊的水体,ETM1/ETM3双波段比值模型可以较好的消除线性天空散射光的影响,克服单波段反演模型在不同水质背景下反演效果不稳定的特点,其反演结果的复相关系数R2可以达到0.98,是水表薄油膜厚度遥感探测的较好波段选择。 相似文献
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本文介绍了用光无源器件及半导体光源改造成的光纤迈克耳孙干涉仪,并设计了可以在教学实验中开设的测量透镜厚度、油膜厚度以及钢板尺微应变的实验,它们的特点是结构简单、容易实现. 相似文献
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Structure properties of silicone oil serving as a liquid
substrate exposed to Ar plasma are investigated in this paper. Under
the action of energetic Ar ions, the surface of silicone oil liquid
substrate exhibits a branch-like fractal aggregation structure,
which is related to the structure evolution of silicone oil liquid
from Si--O chain to Si--O network. The radicals from the
dissociation of silicone oil molecule into the Ar plasma turns the
plasma into a reactive environment. Therefore, the structural
evolution of silicone oil liquid substrate and the reactive radicals
in the plasma space become possible factors to affect the
aggregation of nanoparticles and also the structures and the
compositions of nanoparticles. 相似文献
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利用直流溅射方法在液体基底(硅油)表面成功制备出金属铁薄膜系统,研究了其生长机理及特征的表面有序结构.实验发现铁薄膜的生长过程与液相基底表面非磁性金属薄膜的情况类似,基本服从二阶段生长模型.连续铁薄膜中可观测到尺寸巨大的圆盘形有序结构,其生长演化与溅射功率、沉积时间和真空环境中的生长时间等实验条件密切相关.实验证明,此类有序结构是在薄膜内应力作用下,铁原子及原子团簇在液体表面自由扩散迁移,并最终在硅油基底表面某些区域成核凝聚所致.在较大溅射功率和沉积时间条件下,圆盘外部区域的铁薄膜中形成周期分布的波纹褶皱,其波长约为10 μm,波峰基本与圆盘的边界平行.进一步研究表明:在沉积过程中,由于沉积铁原子的局域能量作用,导致硅油的表面层结构发生改变而形成一聚合物层;在随后的冷却过程中,聚合物层的强烈收缩使铁薄膜处于很大的压应力场中,促使薄膜起皱形成波纹结构.
关键词:
液体基底
铁薄膜
生长机理
有序结构 相似文献
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In this letter, we propose a voltage-controlled optical filter based on electrowetting. The device is made of a transparent cubic cell filled with two immiscible liquids having three indium tin oxide electrodes fabricated on the bottom substrate of the cell. A conductive droplet carrying a color filter is placed on the ITO electrode and the surrounding liquid is density-matched silicone oil. Under zero bias, the droplet is placed in the middle of the substrate and white light passes through the filter and we can see red light on the screen. When a voltage is applied to the device, the filter moves with the liquid based on electrowetting effect, we can see the white light on the screen. Due to the movement of the liquid, our device functions as an optical switcher. The switch time of the device is ~70 ms. The proposed device has a wide application in optical communication, electronic display, and optical switch. 相似文献
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A nearly free sustained copper (Cu) film system has been successfully fabricated by thermal evaporation deposition of Cu atoms on silicone oil surfaces, and a characteristic ordered pattern has been systematically studied. The ordered pattern, namely, band, is composed of a large number of parallel key-formed domains with different width w but nearly uniform length L; its characteristic values of w and L are very susceptible to the growth period, deposition rate and nominal film thickness. The formation mechanism of the ordered patterns is well explained in terms of the relaxation of the internal stress in the films, which is related to the nearly zero adhesion of the solid-liquid interface. By using a two-time deposition method, it is confirmed that the ordered patterns really form in the vacuum chamber. 相似文献
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本课题设计的低温冷冻干燥机以液氮为低温冷源,通过电加热器加热液氮使之汽化,通过控制气体的压力,压出液氮。液氮被压出后流入硅油池的换热器同硅油进行充分换热。在硅油池底部布置一个电加热盘,通过调节加热量,精确控制硅油温度。特制的不锈钢搁板浸入硅油池中进行硅油浴,能够实现良好的传热。测控制系统由上位PC机与下位可编程控制器和数据采集模块共同组成,在PC机上可设置控制参数并进行监控,温度曲线可程序控制,数据采集模块能够自动采集、存储、上传各项数据,数据可以在PC机上处理。 相似文献
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Effect of electric field,stress and environment on delayed fracture of a PZT-5 ferroelectric ceramic
WANG Yi SU Yanjing CHU Wuyang & QIAO Lijie Department of Material Physics University of Science Technology Beijing Beijing China School of Mechanic Electric Control Engineering Beijing Jiaotong University Beijing China 《中国科学G辑(英文版)》2005,48(1):89-100
The combined effect of electric and mechanical loading on fracture of a PZT-5 ferroelectric ceramic in silicone oil has been investigated using a single edge notched specimen. The results show that the fracture toughness and the threshold stress intensity factor of delayed fracture in silicone oil, i.e. stress corrosion cracking, decrease linearly with the increasing applied electric field, either positive or negative. For the PZT-5 ferroelectric ceramics, delayed fracture in silicone oil under sustained positive or negative field can occur, and the threshold field for delayed fracture under sustained positive or negative field decreases linearly with applied stress intensity factor. The combined effect of electric and mechanical loading on delayed fracture in silicone oil includes field-enhancing delayed fracture under sustained load and stress-enhancing delayed fracture in silicone oil under sustained field. 相似文献
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物理化学性能稳定的二甲基硅油常作为电流变液分散相, 当与纳米量级的介电颗粒混合组成电流变悬浮液时, 在非密闭环境下极易挥发, 时间足够长时, 可完全挥发. 本文通过实验研究了纳米二氧化钛颗粒对二氧化钛和硅油组成的悬浮液中硅油挥发增强现象, 分析表明, 纳米颗粒在电流变悬浮液的硅油气-液界面上形成纳米尺度的凸型曲面, 使液面上蒸气压大大提高, 导致挥发增强. 本文还对颗粒浓度, 环境温度和硅油黏度等对硅油挥发增强效应的影响进行了系统的研究和分析. 相似文献