微波谐振器系统的调谐实验研究

圆台谐振腔和微波产生及传输装置可以形成一套和外界独立的微波谐振器系统.由于壁面上电磁压强差的作用,圆台谐振腔可能产生净电磁力,这需要从实验上给予证明.为此首先应对独立的微波谐振器系统进行调谐实验研究,使系统时刻处于谐振状态,这是实验证明净电磁力存在的重要保证.为此,本文对圆台谐振腔进行低信号调谐实验,同时配合调谐元件,准确地调试2.45 GHz频率下的谐振状态,分析温度对谐振状态的影响.实验结果表明该微波谐振器谐振频率2.44895 GHz、品质因数117495.0823,而且当腔体壁温升高时谐振频率减小、品质因数出现周期性振荡.     

一种多次反射怀特池的研究与设计

在传统怀特池的基本原理上,采用高斯光学分析方法推导出了多次反射怀特池的总光程和光斑分布的数学公式。分析表明:连续奇数号光斑间距与连续偶数号光斑间距相等,为两次镜曲率中心间距的2倍,且交替排布;当主镜上有N个光斑时,怀特池总光程OP≈2(N+1)L,其中L为怀特池的基长。根据分析所得结论,对传统怀特池进行了改进,使其能够在减小主镜口径的同时充分利用其有效口径和中间光程。结合设计实例,将结构数据在CODE V上进行模拟和优化计算,通过实际装调验证了所推得的数学公式和结论对指导设计多次反射池的正确性。     

基于扩展光源的LED小角度自由曲面透镜设计

提出了一种基于扩展光源的自由曲面透镜设计算法,运用该算法实现了小角度的均匀照明。在扩展光源与接收面之间建立一种能量对应关系,利用非成像边缘光线法求出自由曲面轮廓曲线的离散数据点,拟合离散点并生成透镜实体。对不同光源尺寸的透镜进行非序列光线追迹模拟,讨论了光源的尺寸对于在均光前提下的发光角度的影响,模拟结果表明,该算法对扩展光源实现均匀照明有较好的适应性,光束的发散角控制在其最小角度。     

基于Matlab平台的电阻特性实验

采用Matlab软件对光敏电阻的伏安特性、光照特性以及热敏电阻温度特性的实验数据进行了处理,实现了方便、快捷、准确的数据处理过程,推进了基于Matlab平台的大学物理实验的教学改革。     

利用传统实验教学优化《医用电子学》课堂

文章在分析虚拟实验教学特点和不足的基础上,结合医用电子学实验教学,从板书指导、实验内容选取、实验环节设计、学生能力培养、实验报告撰写等角度分析阐明了传统实验教学的特点和优势,发现传统实验教学有效提高了课堂效果,弥补了虚拟仿真实验存在的不足。     

The use of Photoshop software to estimate the adhesion and rust‐resistant properties of coating film

A new method for evaluating the adhesion and rust‐resistant properties of coating film is proposed and validated by Photoshop software. A color scanner and Photoshop processing software are used to scan coatings film and analyze images by this method. The percentage of film area removed calculated by pixels is used to classify adhesion of the cross‐cut test ASTM D3359. The area removed is measured by using the functions of area selection and histogram in Photoshop software. The adhesion of 14 samples about standard classification pictures of crosscut adhesion test of ASTM D3359‐02 and self‐made samples, are classified. The percent area removed given by ASTM standard and the percent pixels removed measured by Photoshop is correlated, with the correlation coefficient being 0.997. On the other hand, the rusty areas of regular and irregular graphics are quantitatively determined using $A' = {X'\over X}\times A$ to estimate the rust resistant properties. The determining error of rusty areas compared with the vernier caliper is under 3.0%. Quantitative evaluation for extent of corrosion of the coating is realized. The method is more scientific and specific than the present method of that evaluated by the human mind. Copyright © 2010 John Wiley & Sons, Ltd.     

MDAnalysis: A toolkit for the analysis of molecular dynamics simulations

MDAnalysis is an object‐oriented library for structural and temporal analysis of molecular dynamics (MD) simulation trajectories and individual protein structures. It is written in the Python language with some performance‐critical code in C. It uses the powerful NumPy package to expose trajectory data as fast and efficient NumPy arrays. It has been tested on systems of millions of particles. Many common file formats of simulation packages including CHARMM, Gromacs, Amber, and NAMD and the Protein Data Bank format can be read and written. Atoms can be selected with a syntax similar to CHARMM's powerful selection commands. MDAnalysis enables both novice and experienced programmers to rapidly write their own analytical tools and access data stored in trajectories in an easily accessible manner that facilitates interactive explorative analysis. MDAnalysis has been tested on and works for most Unix‐based platforms such as Linux and Mac OS X. It is freely available under the GNU General Public License from http://mdanalysis.googlecode.com . © 2011 Wiley Periodicals, Inc. J Comput Chem 2011     

Interpretation of analysis of variance models using principal component analysis to assess the effect of a maternal anticancer treatment on the mineralization of rat bones

The aim of this paper is to show how it is possible to extract analytical information from images acquired with a flatbed scanner and make use of this information for real time control of a nickel plating process. Digital images of plated steel sheets in a nickel bath are used to follow the process under degradation of specific additives. Dedicated software has been developed for making the obtained results accessible to process operators. This includes obtaining the RGB image, to select the red channel data exclusively, to calculate the histogram of the red channel data and to calculate the mean colour value (MCV) and the standard deviation of the red channel data. MCV is then used by the software to determine the concentration of the additives Supreme Plus Brightner (SPB) and SA-1 (for confidentiality reasons, the chemical contents cannot be further detailed) present in the bath (these two additives degrade and their concentration changes during the process). Finally, the software informs the operator when the bath is generating unsuitable quality plating and suggests the amount of SPB and SA-1 to be added in order to recover the original plating quality.     

An emphatic orthogonal signal correction-support vector machine method for the classification of tissue sections of endometrial carcinoma by near infrared spectroscopy

A sequential injection analysis (SIA) spectrophotometric method for determining tetracycline (TC), chlortetracycline (CTC) and oxytetracycline (OTC) in different sample matrices were described. The method was based on the reaction between tetracyclines and yttrium (III) in weak basic micellar medium, yielding the light yellow complexes, which were monitored at 390, 392 and 395 nm, respectively. A cationic surfactant, cetyltrimethylammonium bromide (CTAB) was used to obtain the micellar system. The linear ranges of calibration graphs were between 1.0 × 10⁻⁵ and 4 × 10⁻⁴ mol L⁻¹, respectively. The molar absorptivities were 5.24 × 10⁵, 4.98 × 10⁴ and 4.78 × 10⁴ L mol⁻¹ cm⁻¹. The detection limits (3σ) were between 4.9 × 10⁻⁶ and 7.8 × 10⁻⁶ mol L⁻¹ whereas the limit of quantitations (10σ) were between 1.63 × 10⁻⁵ and 2.60 × 10⁻⁵ mol L⁻¹ the interday and intraday precisions within a weak revealed as the relative standard deviations (R.S.D., n = 11) were less than 4%. The method was rapid with a sampling rate of over 60 samples h⁻¹ for the three drugs. The proposed method has been satisfactorily applied for the determination of tetracycline and its derivatives in pharmaceutical preparations together with their residues in milk and honey samples collected in Chiang Mai Province. The accuracy was found to be high as the Student's t-values were found to be less than the theoretical ones. The results were compared favorably with those obtained by the conventional spectrophotometric method.     

组态软件在制冷空调领域的应用研究

文中综合归纳组态软件的功能,介绍组态软件在制冷空调领域里的五种应用方案,它们是虚拟仪表、产品性能测试、系统监控、在线故障诊断、虚拟仿真.并指出组态软件的应用方便易行.