光纤微机电系统压力传感器的理论分析和数值模拟

设计了一种基于微机电系统(MEMS)的光纤压力传感器,证明了光纤MEMS压力传感器在工作状态下可以由法布里_珀罗腔的理论模型解释。推导出了在光纤MEMS压力传感器中硅横膈膜的压力与干涉光强的关系表达式,并对光纤MEMS压力传感器的模型进行了数值模拟,初步确定了在传感器的制作过程中各个物理量的取值。其中腔体半径为300μm、腔体深度为1.42μm、硅横膈膜厚度为23μm,为光纤MEMS压力传感器的加工和制作提供了理论基础。     

Interference of dissociating wave packets in the I2 molecule driven by femtosecond laser pulses

The interference between two dissociating wave packets of the I2 molecule driven by femtosecond laser pulses is theoretically studied by using the time-dependent quantum wave packet method.Both the internuclear distanceand velocity-dependent density functions are calculated and discussed.It is demonstrated that the interference pattern is determined by the phase difference and the delay time between two pump pulses.With two identical pulses with a delay time of 305 fs and a FWHM of 20 fs,more interference fringes can be observed,while with two pump pulses with a delay time of 80 fs and a FWHM of 20 fs,only a few interference fringes can be observed.     

Dispersive white-light spectral two-beam interference under general measurement conditions

Spectral-domain interference of two beams from a white-light source is analysed theoretically and experimentally when the effects of both dispersion in an interferometer and the response function of a spectrometer are taken into account. The spectral interference law is expressed analytically under the condition of a Gaussian response function of a spectrometer. The theoretical analysis is accompanied by experiments employing a dispersive Michelson interferometer and a low-resolution spectrometer. Two experiments with different amounts of dispersion in the Michelson interferometer are realized giving rise to the spectral interference fringes resolved only in the vicinity of the so-called equalization wavelength, at which the group optical path difference between interfering beams is zero. The recorded spectral interferograms are in good agreement with the theoretical ones, which are modelled knowing dispersion in the interferometer and the bandpass of the spectrometer.     

HP-β-CD消除SDS对SDBS同步荧光光谱的影响

十二烷基苯磺酸钠(SDBS)与十二烷基苯磺酸钠(SDS)之间的相互作用,能对SDBS的检测产生明显干扰。实验结果表明,在水溶液中SDS不仅可以增大SDBS的同步荧光强度,还能显著降低SDBS的表观临界胶束浓度。按SDBS的摩尔计量比加入1∶1的羟丙基-β-环糊精(HP-β-CD),可以消除SDS对SDBS的同步荧光强度的干扰。相比于形成胶束,在SDS/SDBS水溶液中,SDBS单体优先选择与HP-β-CD形成量比1∶1的包结物。当水溶液中HP-β-CD的浓度由0增加至0.900 mmol·L~(-1)时,复配体系中SDBS形成胶束的标准摩尔吉布斯函变ΔγGθm由-39.681 k J·mol-1增加至-37.580 k J·mol~(-1)。加入适量HP-β-CD后,能够准确检测SDS/SDBS水溶液中SDBS的含量(临盘采油厂T5站地层水样),方法的回收率为101.0%~101.6%。FT-IR及1H-NMR分析表明,SDBS分子进入HP-β-CD分子内腔的大口径端并形成量比1∶1的包结物,是消除SDS对SDBS检测干扰的根本原因。     

声速测量实验中压电接收端的声压随位置变化的规律

本文介绍了我们所研究的共振干涉接收端声压振幅方程以及用微机解此方程的数学计算方法。     

偏光干涉在物体几何形貌检测中的应用

提出了一种应用晶体光学原理的新型物体几何形貌检测方法，介绍了新方法涉及到的晶体偏光干涉的原理，以及基于这个原理的形貌信号检测方法，并通过实验得到新方法的测量精度约为5μm，测量范围约为7mm，且具有较好的动态特性。     

组件非线性响应人工神经网络建模及在传导干扰分析中的应用

根据描述大信号激励下组件响应的黑箱模型非线性散射参数,提出利用有限实验数据通过人工神经网络建模获得组件非线性散射参数的方法,利用该方法对二极管构成的非线性组件的预测结果与实验测量结果吻合良好。推导了二端口非线性器件与三端口线性器件的非线性散射参数级联计算公式,并讨论非线性散射参数在传导干扰分析中的应用。通过具体实例的计算结果与实测结果的对比,证明了基于人工神经网络学习模型的非线性散射参数获取方法非常便于包含非线性组件的传导干扰分析,这对于系统级电磁效应分析具有重要意义。     

Effects of optical axis direction on optical path difference and lateral displacement of Savart polariscope

A simple method is applied to calculating the optical path difference (OPD) of a plane parallel uniaxial plate with an arbitrary optical axis direction. Then, the theoretical expressions of the OPD and lateral displacement (LD) of Savart polariscope under non-ideal conditions are obtained exactly. The variations of OPD and LD are simulated, and some important conclusions are obtained when the optical axis directions have an identical tolerance of \pm 1^{{\circ}}. An application example is given that the tolerances of optical axis directions are gained according to the spectral resolution tolerances of the stationary polarization interference imaging spectrometer (SPIIS). Several approximate formulae are obtained for explaining some conclusions above. The work provides a theoretical guidance for the optic design, crystal processing, installation and debugging, data analysis and spectral reconstruction of the SPIIS.     

Theoretical analysis on fully differential cross sections for C~(6+)impact ionization of helium

Fully differential cross sections （FDCS） are calculated within a four-body model for single ionization of helium by C6＋ impact at the incident energy of 100 MeV/a.u. （atomic unit）. The results are compared with experimental data and other theoretical predictions. It is shown that our results are in very good agreement with experiment for three small momentum transfers in the scattering plane; however, some significant discrepancies are still present at the largest momentum transfer in both the scattering plane and the perpendicular plane. In actuality, the problem has not been explained by the theory during the last decade. Accordingly, the contributions of different scattering amplitudes to FDCS are analyzed. It is found that for the largest momentum transfer the cross section arising from a destructive interference of the three amplitudes is much smaller than the experimental data. However, the cross section due to the constructive interference of two scattering amplitudes between projectile-ionized electron interaction and projectile-passive electron interaction almost approaches the experimental data.     

Row–column visibility graph approach to two-dimensional landscapes

A new concept, called the row–column visibility graph, is proposed to map two-dimensional landscapes to complex networks. A cluster coverage is introduced to describe the extensive property of node clusters on a Euclidean lattice. Graphs mapped from fractals generated with the probability redistribution model behave scale-free. They have pattern-induced hierarchical organizations and comparatively much more extensive structures. The scale-free exponent has a negative correlation with the Hurst exponent, however, there is no deterministic relation between them. Graphs for fractals generated with the midpoint displacement model are exponential networks. When the Hurst exponent is large enough(e.g., H >0.5), the degree distribution decays much more slowly, the average coverage becomes significant large, and the initially hierarchical structure at H < 0.5 is destroyed completely. Hence, the row–column visibility graph can be used to detect the pattern-related new characteristics of two-dimensional landscapes.