基于Gabor小波纹理特征的目标识别新方法

给出了一种基于Gabor小波纹理特征的目标识别新方法．主要是利用Gabor小波设计了一种多通道小波滤波器。对图像目标直接进行小波变换，用Gabor小波变换系数的模的平均值和其标准方差来表示抽取的图像目标的特征，把获得的小波特征归一化后输入到改进的BP神经网络分类器进行分类识别．最后。进行了一系列的仿真实验，结果表明，这种特征提取方法能有效提取图像目标纹理特征，并且对噪音和形状的变化具有鲁棒性．在应用于目标识别时，神经网络的训练时间减少到lOmin，识别率达到94％．     

Solid Introduction to an ICP-Atomic Emission Spectrometer for the Analyses of Metals Contents of Air Filters

The direct introduction of solid samples (air filters) to the inductively coupled plasma source of an atomic emission spectrometer using a furnace atomizer has been studied. Conditions have been found for the analysis of elements which volatilize with varyling degrees of difficulty. Lead, copper and vandaium compounds retained on glass fibre filters from air pollution studies have been determined. The results are in good agreement with those obtained by means of established sample dissolution/atomic emision methods.     

Surface relief resonant Brewster filters with multiple channels

In this paper, a new type of resonant Brewster filters （RBF） with surface relief structure for the multiple channels is first presented by using the rigorous coupled-wave analysis and the S-matrix method. By tuning the depth of homogeneous layer which is under the surface relief structure, the multiple channels phenomenon is obtained. Long range, extremely low sidebands and multiple channels are found when the RBF with surface relief structure is illuminated with Transverse Magnetic incident polarization light near the Brewster angle calculated with the effective media theory of sub wavelength grating. Moreover, the wavelengths of RBF with surface relief structure can be easily shifted by changing the depth of homogeneous layer while its optical properties such as low sideband reflection and narrow band are not spoiled when the depth is changed. Furthermore, the variation of the grating thickness does not effectively change the resonant wavelength of RBF, but have a remarkable effect on its line width, which is very useful for designing such filters with different line widths at desired wavelength.     

Design and performance of millimeter-wave end-coupled bandpass filters

The design and performance of millimeter-wave microstrip/suspended-stripline end-coupled bandpass filters are presented. Filters in Ka-band (26.5 to 40 GHz) and W-band (75 to 110 GHz) using suspended-stripline and microstrip have been designed. Good agreement between the experimental results and those predicted theoretically was observed. Measured passband insertion losses of less than 1 and 0.5 dB have been achieved in W- and Ka-band, respectively. An extremely wideband waveguide-to-microstrip transition with an insertion loss of 0.25 dB over the full W-band is also presented.     

Strong Nearness Frames Having Enough Cauchy Filters

We prove results establishing sufficient conditions for the sum of two nearness frames to have enough Cauchy filters. From these results and the fact that, in the category of strong nearness frames having enough Cauchy filters and uniform frame maps, complete spatial frames form a coreflective subcategory, follow a variety of results where the open-sets contravariant functor from topological spaces to frames transforms products into sums and inverse limits into direct limits.     

Measurement of Homonuclear J-Couplings from Spin-State Selective Double-/Zero-Quantum Two-Dimensional NMR Spectra

¹H-detected two-dimensional double-/zero-quantum experiments are described for measurement of homonuclear ²J_HH-couplings of NH₂ or CH₂ groups in proteins. These experiments utilize multiple-quantum coherence for determination of the size and the absolute sign of the geminal scalar and dipolar couplings in the presence of broad lines. Spectra are simplified by gradient selection and spin-state selective filters.     

两端对称负折射率缺陷复合光子晶体:多通道滤波和光开关

采用传输矩阵法对两端对称负折射率缺陷复合光子晶体结构[D(AB)mD]N的透射特性进行了研究.结果表明:当N=2时,该结构透射谱的禁带出现两个完全共振透射峰,当N增加时,每个共振透射峰又分裂为N-1条；当复合光子晶体的层数m逐渐增加时,透射峰的品质因子逐渐提高,且分裂的共振透射峰距离逐渐减少；既为该结构实现高品质的多通...     

陶瓷过滤器高温除尘技术的研究进展

对陶瓷过滤元件及结构、滤饼的作用和架桥、过滤器故障安全（CPP）系统及陶瓷过滤器高温气体净化一体化技术等几个方面进行了评述，总结了陶瓷过滤器存在着过滤管破裂、清灰效率下降、管板和器壁的连接及脉冲阀的长期稳定性等几个问题，指出新型陶瓷材料的研究和陶瓷过滤器高温气体净化一体化技术是陶瓷过滤器今后的研究方向．     

Continuously tunable photonic microwave filter based on a spatial light modulator

An optical microwave filter architecture which can be continuously tuned is proposed and demonstrated. The architecture is based on a nematic liquid crystal spatial light modulator in parallel configuration and has the potential to control a large number of taps. Proof-of concept experimental results are provided.     

A new mixed birefringent filter

Birefringent filters can be used for tuning lasers, with some advantages over prisms, gratings and tilted etalons. In this paper the transmission characteristics of a new mixed birefringent filter are investigated. The term ‘mixed’ is used because both circular birefringence and linear birefringence have been utilized in the fabrication of this filter.It has a loss-less core, formed by a cascaded system of alternate rotators and retarders, and a linear polarizer at each end. The performance of this filter is better because of the more effective suppression of side peaks. Unlike previous birefringent filters, this one may be used inside a linear resonator.