简易弧高计的误差分析

本文介绍了使用简易弧高计测量球面弧高时的误差公式，并用实例说明了此类弧高计在一般光学元件件加工测量中的可靠性。     

SnO2水溶胶气-液界面纳米胶粒成膜过程

采用胶体化学法制得稳定的ＳｎＯ２纳米粒子溶胶。在ＬＢ膜槽内，用膜天平考察了溶胶在陈化和均速压缩过程中，气－液界面表面压力的变化。，并用布儒斯特色显微镜，直接观察了陈化过程中界面胶体粒子的片面成膜过程，和均速压缩过程中界面胶体粒子的压缩成膜过程。     

Fabrication of copper oxide nanofluid using submerged arc nanoparticle synthesis system (SANSS)

The optimal parameters are found for preparing nanofluid in our submerged arc nanoparticle synthesis system (SANSS) using a copper electrode. A suspended copper oxide nanofluid is thus produced at the current of 8.5–10 A, voltage of 220 V, pulse duration of 12 μs, and dielectric liquid temperature of 2°C. The CuO nanoparticle are characterized by transmission electron microscopy (TEM), field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), electron diffraction pattern (SAD) and electron spectroscopy for chemical analysis (ESCA). The equality volume spherical diameter of the obtained copper oxide particle is 49.1 nm, regular shape and narrow size distribution.This revised version was published online in August 2005 with a corrected issue number.     

Ambient Spaces of Dimensional Dual Arcs

A d-dimensional dual arc in PG(n, q) is a higher dimensional analogue of a dual arc in a projective plane. For every prime power q other than 2, the existence of a d-dimensional dual arc (d 2) in PG(n, q) of a certain size implies n d(d + 3)/2 (Theorem 1). This is best possible, because of the recent construction of d-dimensional dual arcs in PG(d(d + 3)/2, q) of size ^d–1 _i=0 q ⁱ, using the Veronesean, observed first by Thas and van Maldeghem (Proposition 7). Another construction using caps is given as well (Proposition 10).     

脉冲偏压电弧离子镀TiO2薄膜的力学与光学性能

用脉冲偏压电弧离子镀技术在玻璃基片上制备均匀透明的TiO₂薄膜.利用X射线衍射仪、原子力显微镜、扫描电子显微镜、紫外-可见透射光谱仪和纳米压痕仪等手段,对不同脉冲负偏压下合成薄膜的相结构、微观结构、表面形貌、力学和光学性能进行表征.结果表明，沉积态薄膜为非晶态.脉冲负偏压对薄膜性能有明显的影响.随偏压的增加，薄膜厚度、硬度和弹性模量均先增大后减小，前者峰值出现在100—200 V负偏压范围，后两者则在250—350V范围.300 V负偏压时薄膜硬度最高，薄膜达到原子级表面光滑度，均方 关键词： 2薄膜')" href="#">TiO₂薄膜 脉冲偏压电弧离子镀 硬度 折射率     

Influence of oxygen pressure of ZnO/glass substrate produced by pulsed filtered cathodic vacuum arc deposition

The effects of oxygen pressure on the structural and optical properties of high quality transparent conductive ZnO thin films were studied in detail. ZnO thin films were prepared by pulsed filtered cathodic vacuum arc deposition system under various oxygen pressures on glass substrate at room temperature. With increasing oxygen pressure, the structure and optical properties of films change. The structural and optical properties of the ZnO thin films were investigated using X-ray diffraction, transmittance spectrometry, refractive index, oscillator parameters, energy band gap and Urbach tail. The films show c-axis oriented (0 0 2) hexagonal wurtize crystal structure. It has been found that the grain size of ZnO thin films increases from 16.9 to 22.6 nm with the increase of oxygen pressure from 3.8×10⁻⁴ to 6.9×10⁻⁴ Torr and the crystallinity is enhanced. Average transmittance is about 90% in the visible region of the ZnO thin films. From optical transmittance spectra of ZnO films, the absorption edge shifts towards the taller wavelength with an increase in oxygen pressure. The energy band gap decreases from 3.31 to 3.20 eV with an increase in oxygen pressure. The packing density investigation shows in ZnO films high packing densities (above 0.78) can be obtained.     

Dual-jet plasmatron for medical applications

We present a design for a dual-jet arc plasmatron operating at a frequency of 66 kHz in an argon flow at atmospheric pressure. We present the results of determination of the temperature, electron concentration, and electrode erosion obtained by atomic emission spectral analysis. The proposed convenient design for a dualjet plasmatron and the low erosion of the copper electrodes in the plasma make it possible to use it for medical purposes. Report given at the Fifth International Conference on Plasma Physics and Plasma Technologies (PPPT-5), 18–22 September 2006, Minsk, Belarus. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 139–140, January–February, 2007.     

Corrosive behavior of chromium carbide-based films formed on steel using a filtered cathodic vacuum arc system

The formation of chromium carbide-based hard-coatings on steels using a 90°-bend filtered cathodic vacuum arc (FCVA) has extensive industrial applications; such coatings are free of macroparticles and exhibit excellent characteristics. In this investigation, a working pressure of C₂H₂/Ar was adopted to synthesize amorphous chromium carbide film (a-C:Cr) and crystalline chromium carbide film (cryst-Cr₃C₂) from a Cr target (99.95%) at 500 °C under a substrate voltage of −50 V. The corrosion behavior of a-C:Cr coated on steel (a-C:Cr/steel) and cryst-Cr₃C₂ coated on steel (cryst-Cr₃C₂/steel) were compared in terms of open-circuit potentials (OCP) and polarization resistance (R_p) in an aerated 3.5 wt% NaCl aqueous solution, as determined by electrochemical impedance spectroscopy (EIS). The XRD results indicated that the transformation of a-C:Cr to cryst-Cr₃C₂ is distinct as the working pressure declines from 1.2 × 10⁻² to 2.9 × 10⁻³ Torr. The OCP of a-C:Cr/steel and cryst-Cr₃C₂/steel resemble each other and both assembly are nobler than uncoated steel. The R_p of the coatings exceeds that of the uncoated steel. The SEM observation and the EIS results demonstrate that the cryst-Cr₃C₂/steel more effectively isolates the defects than dose a-C:Cr/steel.     

An algorithm for fitting circular arcs to data using the <Emphasis Type="Italic">l</Emphasis><Subscript><Emphasis Type="Italic">1</Emphasis></Subscript> norm

There are many applications of fitting circular arcs to data. We have for example, system control, using a computer controlled cutting machine, approximating hulls of boats, drawing and image techniques. Out of these applications comes the least squares norm to be the most commonly used criterion. This paper examines how the l ₁ norm is used which seems to be more appropriate than the use of least squares in the context of wild points in the data. An algorithm and different methods to determine the starting points are developed. However, numerical examples are given to help illustrate these methods.      

Influence of processing variables on the formation of La2Zr2O7 in transferred arc plasma torch processing

The transferred arc plasma (TAP) torch process has various noteworthy features such as extremely high temperatures, low environmental impact and short processing time which makes it the most suitable technique for synthesizing ceramic composite materials. Furthermore, it is a direct two-step technique which by its virtue of high temperature and power density paves way for high production rate. Hence in this study, an effort has been made to utilize the TAP torch processing technique for the bulk production of La₂Zr₂O₇ with time effectiveness from the mixture of La₂O₃ and ZrO₂ powders (1:2 mol ratios) which were ball milled for 4 h. For this purpose, transferred arc plasma torch was specially designed in laboratory scale level and the operating parameters were optimized in order to achieve maximum La₂Zr₂O₇ formation efficiency. In this study, the phase and microstructure formation of the processed samples was analyzed via X-ray diffraction (XRD) and scanning electron microscope (SEM) images respectively. Moreover, EDX analysis was incorporated to highlight the superior influence of the longer processing time on the stoichiometric ratio of ZrO₂/La₂O₃ in the processed sample as against input power and the gas flow rate.