激波管风洞中叶栅测压实验与计算研究

本文利用激波管平面叶栅风洞在四种工况下进行了某叶型叶表压力分布测量实验。该类短周期实验方式的测量精度是值得关注的大问题，为此文中对实验误差及短周期实验测量的合理性进行了分析。继而将实验数据与两种模型下的数值计算结果进行了比较，其中实验结果与按实际情况建立的模型１计算结果吻合。通过实验结果与模型２计算结果比较发现，实验中存在着影响叶栅通道流动周期性的因素，本文仔细分析了该因素可能产生的影响，为今后对该风洞实验段进行改造提供了基础。     

基于PASCO转动运动传感器测量刚体转动惯量

PASCO转动运动传感器可以精准地测量并实时地记录物体转动时的角速度。在落体法测量刚体转动惯量的实验中，为了提高实验的精度，将PASCO转动运动传感器与刚体转动惯量实验仪相结合，用PASCO转动运动传感器直接测量角速度并计算角加速度。改进后的仪器简化了实验步骤，提高了实验精度。对圆盘、圆环和圆柱试样的转动惯量进行测量，三组实验的相对误差分别为0.2%、0.7%和0.3%,实验结果准确。通过实验结果可得，改进后的实验仪器操作简单且测量精度很高。     

恢复系数的测量

考虑到空气的粘性，理论计算了弹力球的运动位移随时间的变化规律，从一定高度释放弹力球，实验测量不同弹跳次数所需时间，运用级数理论，得出弹力球与桌面碰撞时的恢复系数，并提出了3种实验方案，理论计算和实验测量结果均表明空气的粘性对测量结果影响很小。     

纳米银在低温下电阻率的研究

本文详细报道了对系列纳米银样品在低温下电阻率的测量结果，并把结果与在同一实验装置下测量多晶银的测量结果进行了比较。     

激光损伤He—Ne散射探测法研究

介绍了He-Ne散射检测激光损伤的原理和实验装置，分析了散射信号及激光损伤的内在关系。实验表明，散射信号与薄膜的激光损伤尺度与形貌有关，对于本次实验，最小探测的激光损伤尺度为20μm左右。与显微镜和等离子体闪光法实验对比显示，He-Ne散射测量能判定薄膜激光损伤的发生，准确测量激光损伤闽值，测量结果与显微镜观察法符合较好。     

一种测量水的汽化热的实验设计

文中设计了一种测量水的汽化热的实验设备，并用该设备测量了水的汽化热.实验结果表明，这种实验方案测量出水的汽化热与公认值十分接近，得到的实验结果误差小于1%.该方法重复性较好，实验操作便捷，仪器的开发成本较低，有极高的推广价值.     

共轭涡旋光干涉精密位移测量方法与系统

为实现高精度大量程精密位移测量，提出了一种基于涡旋光共轭干涉的精密位移测量方法。通过建立位移过程中涡旋光共轭干涉图样的旋转角弧度与位移之间的数学关系，实现了对旋转角弧度的精确提取，得到了高精度的精密位移测量结果。基于该原理对测量方案进行了光学系统设计与仿真，研制了实验系统并进行了实验测试。当标准位移为20 nm时，实验测量结果的误差为25 pm，相对误差为0.13%，证明了所提亚纳米级精密位移测量方案的有效性。所提系统还可通过计量干涉图样旋转圈数进行大测量范围的精密位移测量。实验结果表明，所提方案可在30μm范围内实现精密位移测量。     

气垫导轨实验中的粘滞阻力

给出了阻尼振动实验中测量圆板阻力的结果并提出了一种改进的实验方法，通过实验与粘滞阻力进行比较并对实验结果进行了定性分析。     

GaAs／AlGaAs发光二极管列阵场分布特性的电光测量

应用一种新颖的无损伤测量技术－连续波电光检测法（ＣＷＥＯＰ）对ＧａＡｓ／ＧａＡｌＡｓ单异质结发光管列阵电场分布进行了扫描测量。实验结果反映了器件内电流注入的方向和载流子扩展情况；通过比较各单元电场分布，反映器件发光均匀性。文中详细介绍了测量原理、实验装置和实验结果及讨论，最后用计算机对电场分布作了模拟计算并与实验结果进行了对照。     

声速测量实验原理释疑

目前常见的一种声速测量实验中，通常认为接收端测量到的信号是按驻波规律变化的，按照这个原理虽然能得到正确的声速测量结果，但是也有许多明显不合理的地方，本文对这个实验提出了新的解释，不仅能够很好地与实验现象符合，也避免了理论上的矛盾。     

Effect of color noise on the processing of optical signals using the swarm intellect algorithm

An approach based on stochastic particle swarm optimization is used for the mathematical processing of spectral profiles with noise. Noises with different values of the Hurst index, which characterizes the noise component based on the prevalence of its low- or high-frequency components, is used to test the algorithm’s stability with respect to noise. The Hurst index is varied from 0.1 to 0.9. The effect color noise with levels of 1 to 10% has on the processing of optical signals using the particle swarm optimization algorithm is analyzed. The method is shown to be stable with respect to noise with a level of 10% if the Hurst index does not exceed a value of 0.5.     

Invertibility of parabolic pseudodifferential operators with rapidly increasing symbols

We consider pseudodifferential operators with rapidly increasing double symbols analytic with respect to the variable dual to the time on the lower complex half-plane. We construct invertibility theory for these operators in weighted Sobolev spaces with weights related to growths of symbols and give applications to heat equations with potentials of power, exponential, and superexponential growths. Dedicated to the memory of Professor Leonid Romanovich Volevich     

High order approximate low frequency theory of elastic anisotropic lining and coating

A problem of the dynamic behavior of an elastic layer coupled to one or two thick elastic solids is considered. All the materials may possess a general anisotropy and the layer is assumed to be thin enough with respect to the characteristic wavelength. Introducing the asymptotic power series with respect to the thickness-over-wavelength ratio for the main quantities and using the asymptotic integration method the displacements and stresses on the layer surfaces are related. Thus, the so-called impedance boundary conditions (IBC) are deduced for three cases--for a coated substrate with given displacements or with given stresses on the surface and for two substrates with a layer in between. In contrast to previous papers these IBC are obtained for the most general situation with the asymptotic accuracy up to the sixth order, uniform with respect to the representation of the displacements and stresses. Presented theory can be used for studying the surface and interface phenomena as well as for calculating fields and spectra of layered solids. The results are validated numerically and compared with those of other authors.     

High-contrast white-light Lau fringes

We present a new optical assembly with which to achieve Lau fringes with totally incoherent illumination. Gratinglike codification of the spatially incoherent source combined with an achromatic Fresnel diffraction setup allows us to achieve Lau fringe-pattern visibility of almost 100% with broadband light. The white-light character to our proposed setup is in stark contrast to previous monochromatic implementations. Potential implications of this fact are identified.     

Fluctuations and correlations in the string clustering approach

The fluctuations due to the clustering of color sources can explain the behaviour of the scaled multiplicity variance and transverse momentum fluctuations with centrality. They also predict a nonmonotonic behaviour with centrality for the multiplicity associated to high-p_T events. The clustering of color sources gives rise to an increase in the long-range correlations with centrality as well as to a supression at high centrality with respect to superposition models.     

基于遗传算法的输电线路无人机巡检路径规划

针对无人机有效、安全巡检输电线路的路径问题,提出了一种基于遗传算法的输电线路无人机巡检路径规划方法,采用极坐标编码方式对无人机巡检路径构造染色体。结合实际情况中的无人机巡检各种约束问题,设计了适合于无人机巡检路径规划的遗传算子。实验结果证明算法能综合考虑各种因素,提高了全局寻优能力,是解决实际输电线路无人机巡检路径规划问题的较好办法。     

Muon precession in iron single crystals

Changes in the muon precession signal in iron with angle of the magnetization with respect to the crystal axes are not due to intrinsic changes in hyperfine field with angle in unstrained single crystals. To confirm this with rectangular plate samples it was necessary to study methods of correcting for demagnetizing fields.     

Acoustic field evaluation of asphalt mixtures with crumb rubber

The aim of this study is to characterize the acoustical behavior of bituminous mixtures fabricated with recycled rubber crumb. Acoustic field measurements of the tire/pavement interaction in close proximity to the contact patch were carried out with a trailer with a protective chamber (TiresonicMk4-LA²IC). The survey was conducted on a test track with several experimental sections paved with a gap-graded mixture. Different methods of incorporating crumb rubber in the mixture were used: (i) into binder and (ii) with the aggregate materials. Close proximity sound levels are assigned to the gap-graded mixtures containing rubber and compared to that of a reference mixture without rubber. It is shown that asphalt mixtures fabricated with the addition of crumb rubber to the aggregate material (dry process) managed to reduce the noise from the tire/pavement interaction up to 2 dB(A).     

Influence of synchrotron radiation on morphological features of a polymethylmetacrilate thin film

The interaction of polymethylmetacrilate (PMMA) hard films with synchrotron radiation (SR) has been studied by atomic force microscopy (AFM). It has been found that the roughness changes from 1.85 to 2.98 nm with an increase in the irradiation time for the selected beam with the energy corresponding to the hard X-ray region λ = 0.2 nm. The roughness decreases from 6.41 to 2.36 nm with an increase in the irradiation time from 1 to 17 min when photons with a lower energy are used. The interaction of radiation with PMMA leads to the appearance of nanohillocks, the average diameter and height of which depend directly proportionally on the spectral composition and SR exposure time. The revealed effects of interaction of synchrotron radiation with PMMA will help to correct the X-ray lithography conditions in electron engineering (PMMA is the basis for X-ray resist) and will allow one to control the roughness degree of the PMMA surface that is the basis for intraocular lenses.     

基于高光谱技术的病害早期胁迫下黄瓜叶片中过氧化物酶活性的研究

应用可见/近红外高光谱对细菌性角斑病早期胁迫下的黄瓜叶片中所含过氧化物酶(peroxidase,POD)活性进行检测。在380~1 030 nm光谱范围获取120个样本(健康,病害轻微感染1级和2级)的光谱曲线,并使用分光光度计法测量感染病害样本中的过氧化物酶活性值。采用单因素方差分析(analysis of variance,ANOVA)对三种不同程度早期病害胁迫下过氧化物酶活性值进行统计分析,结果表明不同程度病害胁迫下黄瓜叶片中的过氧化物活性存在显著性差异(p=0.05)。采用SPXY方法将样本分为建模集(80个样本)与预测集(40个样本)。采用random frog(RF)和回归系数法(regression coefficient,RC)方法提取特征波段,并建立过氧化物酶活性值的偏最小二乘回归(partial least square regression,PLSR)预测模型。最终得到RF-PLSR具有最佳的预测效果,预测集相关系数为0.816,预测均方根误差为11.235。研究结果表明高光谱结合化学计量学方法可以实现细菌性角斑病早期胁迫下黄瓜叶片中过氧化物酶活性的测定,为植物病害的早期无损诊断提供参考。