Real-time three-dimensional infrared imaging using fringe projection profilometry

Infrared thermography determines the surface temperature of an object or human body. It is a promising imaging technology for medical and biological observations due to its contactless and completely non- invasive properties. However, traditional two-dimensional （2D） infrared thermography cannot retain the spatial information, and thus provides only qualitative diagnosis information. A novel real-time three- dimensional （3D） infrared imaging system which takes full advantages of high-speed, high-quality, high- sensitivity, and low-cost in 3D thermograph is presented. We demonstrate the real-time 3D thermal imaging at the speed of 24 frmnes per second （fps）, with resolution of 640 ×480 points. Experimental results demonstrate quantitatively measurement of temperature distribution of 3D surfaces in real-time is realized with this system.     

基于CDMA的布拉格光纤光栅传感系统的仿真分析

讨论了光纤光栅传感系统中常用的复用技术及其限制,阐述了利用CDMA技术实现光纤布拉格光栅阵列波长解调的复用方式,对系统的原理和性能进行了理论分析。在此基础上通过MATLAB做了基于CDMA的光纤光栅传感仿真分析,仿真结果表明该方法能区分反射波长重叠的光栅,从而提高FBG网络复用的频带利用率。     

Modulation of electroencephalograph activity by manual acupuncture stimulation in healthy subjects:An autoregressive spectral analysis

To investigate whether and how manual acupuncture(MA) modulates brain activities,we design an experiment where acupuncture at acupoint ST36 of the right leg is used to obtain electroencephalograph(EEG) signals in healthy subjects.We adopt the autoregressive(AR) Burg method to estimate the power spectrum of EEG signals and analyze the relative powers in delta(0 Hz-4 Hz),theta(4 Hz-8 Hz),alpha(8 Hz-13 Hz),and beta(13 Hz-30 Hz) bands.Our results show that MA at ST36 can significantly increase the EEG slow wave relative power(delta band) and reduce the fast wave relative powers(alpha and beta bands),while there are no statistical differences in theta band relative power between different acupuncture states.In order to quantify the ratio of slow to fast wave EEG activity,we compute the power ratio index.It is found that the MA can significantly increase the power ratio index,especially in frontal and central lobes.All the results highlight the modulation of brain activities with MA and may provide potential help for the clinical use of acupuncture.The proposed quantitative method of acupuncture signals may be further used to make MA more standardized.     

自仿函数分数阶导数的分形维数

研究一类自仿函数的分数阶导数,获得了自仿函数的Weyl-Marchaud分数阶导数的图像盒维数,证明了分数阶导数的阶与分形维数之间的线性关系.     

Empirical likelihood-based subset selection for partially linear autoregressive models

Based on the empirical likelihood method, the subset selection and hypothesis test for parameters in a partially linear autoregressive model are investigated. We show that the empirical log-likelihood ratio at the true parameters converges to the standard chi-square distribution. We then present the definitions of the empirical likelihood-based Bayes information criteria （EBIC） and Akaike information criteria （EAIC）. The results show that EBIC is consistent at selecting subset variables while EAIC is not. Simulation studies demonstrate that the proposed empirical likelihood confidence regions have better coverage probabilities than the least square method, while EBIC has a higher chance to select the true model than EAIC.     

具有中间亏指数的线性哈密顿算子的点谱

本文讨论具有任意亏指数d的自伴线性哈密顿算子点谱与对应的线性哈密顿系统的平方可积解之间的关系.若对于某个实开区间中的任意点λ,系统总有d个线性无关解,则它的任何自伴算子的点谱在这个开区间上是不稠密的.     

光交联交替层状自组装(LBL)抗菌膜的制备及其性能研究

针对静电超分子作用的交替层状自组装(LBL)膜稳定性差、易分解和难以实现应用的问题,设计合成了一种光交联型抗菌LBL多层膜.该LBL多层膜由修饰有光敏邻硝基苄醇分子的透明质酸(HANB)与季铵化的壳聚糖(ACS)通过静电作用在基片上交替沉积而成.光照后,HANB上的邻硝基苄醇分子产生活性醛基,与邻近壳聚糖上的氨基发生亚...     

基于Geant4-CST联合仿真的条纹变像管光电子产生与控制

碘化铯（CsI）光电阴极广泛应用于超快诊断中,光电子的空间分布、能量分布、时间分布等与条纹变像管的整体性能有着密切的关联。本文联合粒子仿真软件Geant4和三维电磁软件CST实现了对CsI光电阴极的光电子产生与控制过程的全动态模拟。采用Geant4软件对CsI光电阴极的光电转换过程进行建模,分析了二次电子出射能量、时间、位置、角度等发射特性;通过数据交互,统计了出射光电子的分布规律,然后将其应用于CST中建立阴极发射模型,并在CST中设计出一款弧矢、子午方向上放大倍率皆为2的各向异性聚焦条纹变像管。     

基于T形管的自复叠制冷系统性能分析

T形管中非共沸工质的组分分布对组分可调热力循环性能有重要影响。但目前的研究均是基于理想分离假设分析T形管对热力循环的影响。为研究T形管实际分离性能对热力循环性能的影响,设计了一种基于T形管的新型自复叠制冷系统。对制冷工况下T形管中R134a/R600a的组分分布进行数值模拟,基于数值模拟结果对新型自复叠制冷系统性能进行计算分析。结果表明：T形管出口的流量分配比越高,其分离效率越大。当干度大于0.8或R134a质量分数大于0.7时,T形管两个出口的分离效率相对较小。与无分离的制冷系统相比,基于T形管的自复叠制冷系统的COP可提升0.83%至18.69%,单位容积制冷量可提高3.09%至36.2%,过冷器热负荷可降低11.6%至31.3%。