共查询到20条相似文献,搜索用时 343 毫秒
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《中国计量学院学报》2015,(2):212-215
反射率是太阳能聚光镜的关键参数.依据不同玻璃透过率和不同镀膜工艺制备了一系列太阳能聚光镜样品.采用Lambda1050紫外/可见/近红外分光光度计测量了这些样品的反射率曲线,并结合太阳光谱权重计算得出反射率.结果表明,相同条件下,玻璃的透过率越高则反射镜的反射率越高;反射镜反射率随着银含量增大而增高,并趋于饱和;铜含量对反射率影响较小. 相似文献
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碳纤维复合材料空间反射镜制造技术研究进展 总被引:1,自引:0,他引:1
碳纤维复合材料(CFRP)具有比刚度高、热稳定性好,可设计性强等特点,成为轻量化反射镜制造的新型理想材料,特别适合大口径、高分辨率空间反射镜的制造。简单介绍空间光学反射镜的国内外研究应用的现状。根据反射镜的特点介绍了碳纤维复合材料的材料选择要求,以及国外常用碳纤维复合材料预浸料体系。碳纤维复合材料反射镜制造方法与传统光学材料反射镜的制造不同,一般采用高效、快速、制造成本低的复制工艺来实现。总结了碳纤维复合材料反射镜的复制工艺和反射镜复制精度的影响因素,影响因素包括复制模具、预浸料铺层、反射镜变形、纤维印痕现象、尺寸稳定性以及反射镜尺寸等,并对前五项影响因素提出相应的控制措施来减小影响程度。重点阐述了反射镜纤维印痕现象的成因和解决方法,以及控制尺寸稳定性的关键。 相似文献
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某光学组件在高低温冲击试验后反射镜出现裂纹。通过宏观分析、剪切强度试验、硬度测试、线膨胀系数试验等方法对反射镜开裂原因进行了分析。结果表明:DG-4胶黏剂配比不当,对反射镜产生了较大的固化应力,加之高低温冲击试验中,急速升降温使得反射镜受到了较大的热应力,在两者的共同作用下反射镜发生开裂。 相似文献
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耿桂宏 《真空科学与技术学报》2007,27(2):159-162
铝膜反射镜是反射式空间聚光太阳电池阵的重要组成部分。通过对铝膜反射镜电子、质子、紫外、原子氧环境等一系列辐照及环境试验,研究和考察了铝膜反射镜反射率的变化和空间环境适应性。研究结果表明,铝膜反射镜适应地球同步轨道环境条件下,反射镜平均反射率在15年寿命末期大于75%;在低地球轨道环境中有必要对铝膜反射镜进行抗原子氧侵蚀防护。 相似文献
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针对空间光学遥感器反射镜离子束加工过程中,离子束瞬态大热流密度造成加工过程镜体温度急剧上升引起的热应力问题,利用UG8.5软件flow thermal高级仿真模块对反射镜组件的温度场进行瞬态仿真,预示加工过程的温度场,将温度场映射至结构有限元模型,利用NX NASTRAN计算出反射镜组件的热应力分布。根据反射镜组件的加工环境和结构特点,采取导热措施将加工过程热量疏导至大热容工装板。结果表明,采取热控措施后反射镜组件加工过程最高温度降低15%,对应的最大热应力降低27%,有效降低了反射镜组件的热应力;通过ZYGO干涉仪检测加工完成后的反射镜面型,面型精度优于λ/50,为空间光学反射镜离子束加工提供了有效的保障。 相似文献
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Hu Zhao Chongguang Liu William W. Sampson Alexander S. Eggeman Brian Derby 《Advanced Engineering Materials》2023,25(19):2300509
Transmission electron microscopy investigation of networks of pentatwinned silver nanowires has identified the presence of nanoscale defects within individual wires, showing narrow regions of banded contrast normal to the nanowire axis (bamboo faults). Structural analysis using machine learning decomposition of scanning precession electron diffraction data identifies these bamboo faults as a pair of twist boundaries normal to the wire axis creating low energy coincident site lattices between the faulted region and the parent nanowire. This leads to a conservation of the relative misorientation of the twinned structure within the faulted region, leading to an apparent local rotation of the nanowire. Their presence after spraying and nonthermal processing suggests that they may form during nanowire synthesis. However, examination of the networks before and after cyclic straining finds an increase in the density of the defects, indicating that they may also form as a result of mechanical deformation. 相似文献
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Metallized polymer substrates offering highest reflectance are not yet state of the art. Coating organic substrate materials is still a task that is connected with multiple problems. Insufficient adhesion of coatings on polymer substrates represents one of the main difficulties. We could show by experiment that aluminium and silver layers indicate good coating adhesion on many different polymers if they are deposited by vacuum evaporation considering certain process parameters. High reflectance values and a good climatic stability of the metal coated polymer parts are other important challenges to plastic mirrors. By performing roughness measurements on the different polymer samples and by comparing reflection values obtained after coating these samples the impact of the polymers surface quality on the reflectance after metal coating has been investigated. Particularly high reflectance above 97% was realized with a protected silver mirror as well as with dielectric enhanced aluminium. Applying these layer systems excellent reflection properties has been obtained on several plastic substrates comparable to those on glass mirrors. Furthermore the dielectric layers used for reflection enhancement showed the ability to protect the aluminium coating against climatic influences. 相似文献
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The preparation and characterization of a reference mirror of protected aluminum (Al) is reported. The mirror is made of 50-60-nm-thick Al film, coated with several-nanometer-thick A12O5 and 30-nm-thick film of AIN. The mirror characterization is based on reliable and precise reflectance measurements relative to a silicon- (Si-) wafer reference mirror. The simple phenomenological Drude-Lorentz model is applied for modeling the dispersion relations n(lambda) and k(lambda) of the Al film. The reflection of the protected Al mirror is determined in the 400-800-nm spectral range with accuracy better than 0.01 for p- and s-polarized light at angles of incidence from 0 degrees to 70 degrees. The accuracy has been confirmed with an evaporated thin silver film with known n(lambda), k(lambda), and d derived by photometric measurements at normal light incidence. 相似文献
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Metal-dielectric multilayers have versatile optical properties that can be used in many applications. The special properties of metal films in the near UV region are analyzed in terms of the d-band contribution to the plasma oscillation. The important parameters that determine the multilayer optical properties such as skin depth dependence on the wavelength and the thickness of silver films have been calculated. The morphology of silver films on titanium dioxide has been observed by TEM. The results indicate that an optimal thickness exists for near UV transparency, and that may be related to the resonance of voids and interface enhanced resonance-tunneling transmission of semi-continuous silver films. A special heat mirror with high transparency in the near UV region was designed and fabricated according to the optimal thickness of silver; it has been found to exhibit sound optical properties. 相似文献
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We present a facile method for ordering flowerlike structures of silver nanosheets on an aluminium covered surface. It is shown that using a combination of electron-beam lithography and standard silver mirror reaction, structures of silver nanosheets can be grown at predefined positions as single or multiple “flowers”, depending on the underling bare aluminium pattern. Arbitrary shaped areas, defined by electron-beam lithography, can be covered with closely packed silver nanosheets. 相似文献
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Li D Chen J He H Zhang R Chen W Lu X Wang X Xue G 《Journal of nanoscience and nanotechnology》2012,12(1):361-364
Monolayer detection on metal surface requires ultra high sensitivity. Sum Frequency Generation Spectroscopy (SFG) and Surface Enhanced Raman Spectroscopy (SERS) are regarded as two powerful techniques with submolecular sensitivity to detect adsorbents on metal surface. However, in some cases it's still challenge to characterize molecules or groups with relatively high intramolecular symmetry, such as 4-Nitrothiophenol (4NTP), on flat metal surface even combining these two techniques. Basically, this is due to that 4NTP with para-substituted phenol groups is SFG insensitive while flat metal surface is unfavorable to yield strong SERS enhancement. In this concern, a simple and efficient method, silver mirror method, was employed to facilitate the detection of 4NTP SAM on flat gold surface. Silver nanopheres with diameters around 300 nm was fabricated through silver mirror reaction and in situ formed milky overlayer on top of 4NTP SAM adsorbed on gold surface. Significant enhancement on SERS signal can be achieved with such special assembly structure of the "metal-molecule-metal" system. Generally, the silver mirror method provided a complementary approach to facilitate the spectroscopic applications of molecule level detection on various metal surfaces in situ. 相似文献
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对高精度太阳能抛物面镜收集器和大孔径低损耗PMMA/Ag泄漏型空芯光纤进行了设计与研究,安装在收集器上的光电追踪器保证了入射光线聚焦在抛物面轴上,有利于聚焦光斑有效地传输到空芯光纤内。与传统的太阳能利用装置相比较,本装置不需要进行能量转换,因此效率高,结构简单,可以实现聚焦后太阳能的远距离高效传输。 相似文献
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Kawachi T Kado M Tanaka M Hasegawa N Nagashima K Sukegawa K Lu P Takahashi K Namba S Koike M Nagashima A Kato Y 《Applied optics》2003,42(12):2198-2205
A two-beam chirped-pulse-amplification Nd:glass laser system dedicated to x-ray laser research is described. Each beam provides an output energy of 20 J with a typical pulse duration of 1.3 ps. A prepulse of variable duration is generated by use of a novel, to our knowledge, optical system. A reflection optical system, comprised of an off-axis parabolic mirror and a spherical mirror, produces a line focus with 6-mm length and 165-microm width without chromatic aberration. By use of this pumping laser system, the nickel-like silver x-ray laser at a wavelength of 13.9 nm has been demonstrated. 相似文献