Log-polar transform-based wavelet-modified maximum average correlation height filter for distortion-invariant target recognition

In this paper, we report a log-polar transform-based filter for in-plane rotation and scale-invariant target recognition. The log-polar transform is a known space-invariant image representation used in several image vision systems to eliminate the effects of scale and rotation in an image. In case of in-plane rotation invariance, peaks shift horizontally, while in case of scale invariance, peaks shift vertically. For full out-of-plane rotation-invariance (0–360°), log-polar transformed images are used to train the wavelet-modified maximum average correlation height (WaveMACH) filter. Correlation peak height and peak-to-sidelobe ratio have been calculated as metrics of goodness of the log-polar transform-based WaveMACH filter. This filter would reduce the memory requirement for filter storage in a practical system. Simulation results have been presented.     

Strategies for discovery and optimization of thermoelectric materials: Role of real objects and local fields

Thermoelectric materials provide a renewable and eco-friendly solution to mitigate energy shortages and to reduce environmental pollution via direct heat-to-electricity conversion. Discovery of the novel thermoelectric materials and optimization of the state-of-the-art material systems lie at the core of the thermoelectric society, the basic concept behind these being comprehension and manipulation of the physical principles and transport properties regarding thermoelectric materials. In this mini-review, certain examples for designing high-performance bulk thermoelectric materials are presented from the perspectives of both real objects and local fields. The highlights of this topic involve the Rashba effect, Peierls distortion, local magnetic field, and local stress field, which cover several aspects in the field of thermoelectric research. We conclude with an overview of future developments in thermoelectricity.     

Wavelet-modified maximum average correlation height filter for out-of-plane rotation invariance

In this paper, we implement a wavelet-modified maximum average correlation height (WaveMACH) filter for recognition of 0-360° out-of-plane rotated targets employing hybrid digital-optical correlator architecture. A chirp function is used with the synthesized WaveMACH filter, which focuses the correlation signals in three different planes, thereby providing the choice of recording a single correlation peak at a particular plane. Signal-to-noise ratio and peak-to-sidelobe ratio have been calculated as metrics of goodness of the proposed WaveMACH filter.     

Synthesis of bandpass grid filter for linear polarized millimeter wave

A method based on equivalent circuit and transmission line model is proposed to design narrow bandpass grid filters in short millimeter wave. Several bandpass filters with 2, 3 or 4 element inductive wire grids in the 70GHz region have been designed with Butterworth or Chebyshev characteristic for linear polarized wave. The agreement between measurement and design theory is good and this proves the rationality and practicality of our design theory.     

三环位相型光瞳滤波器的横向超分辨与轴向焦深扩展

用矢量衍射方法分析了线偏振光入射到带有三环位相型光瞳滤波器的高数值孔径物镜时,焦点的轴向和横向光强分布.数值模拟结果表明,高数值孔径物镜聚焦时需同时考虑光强的轴向和横向分布.通过加入三环位相光瞳滤波器,在实现横向超分辨的同时实现了光学系统轴向焦深扩展和轴向光强分布平坦化,并且位相调制深度变化时,会出现轴向焦移现象.对三环位相光瞳滤波器结构进行了优化,得出了优化结果. 关键词： 光学超分辨 扩展焦深 位相型光瞳滤波器 矢量衍射方法     

准平行光干涉的滤波型多抖动相控方法研究

正提出了一种准平行光干涉的滤波型多抖动相控方案,对该方案的相干光强进行了理论分析,在此基础上提出了滤波型多抖动法的相控原理,进行了滤波型多抖动法的相控数值分析和模拟实验.结果表明:该方法可识别出各路光波的相位差,反馈与相位差信号成比例的直流电压去控制相位调制器,可实现相位差的校正,相位控制电压输出范围为0.03—4.45 V,控制带宽为2.5 kHz.     

Analytical methods for quality control of combinatorial libraries

This literature review covers the applications of analytical techniques to solid phase organic chemistry and combinatorial chemistry published between June 96 and September 1997. Highlighted are mass spectrometry, NMR, IR and chromatographic analyses of solid phase synthesis reactions and combinatorial libraries.     

一种血流变参数在体实时探测方法

介绍了一种新的在体实时监测血流变参数的光学方法——光散射法。设计了一种实用的同轴多光纤探针装置。在装置中间,其中一根光纤用于传输入射激光,周围多根光纤与中心光纤等间隔,用于接收血液中的散射光。用扫描法布里-珀罗干涉仪产生散射光谱。结果表明,用该装置测得了含成分的液体、实血和不同血液成分的光散射光谱。     

4f结构间距失调对达曼类滤波器输出脉冲特性的影响

 研究了4f结构的飞秒脉冲时空变换整形装置在各元件间距不等的情况下对脉冲输出特性的影响,理论分析了间距失调效应对等间距和不等间距达曼光栅滤波器的脉冲输出特性的影响。结果表明4f结构间距失调后无论是能量还是平均度都不如等间距高,中心脉冲能量变小,其它级次脉冲生出更多旁瓣;失调量越小,输出的脉冲质量越高,对于f为12 cm的装置,当失调量小于1 cm时,对输出脉冲影响较小。     

4f结构间距失调对达曼类滤波器输出脉冲特性的影响

研究了4f结构的飞秒脉冲时空变换整形装置在各元件间距不等的情况下对脉冲输出特性的影响,理论分析了间距失调效应对等间距和不等间距达曼光栅滤波器的脉冲输出特性的影响。结果表明4f结构间距失调后无论是能量还是平均度都不如等间距高,中心脉冲能量变小,其它级次脉冲生出更多旁瓣;失调量越小,输出的脉冲质量越高,对于f为12 cm的装置,当失调量小于1 cm时,对输出脉冲影响较小。     

Normalized LMS digital filter for chromatic dispersion equalization in 112-Gbit/s PDM-QPSK coherent optical transmission system

High bit rates optical communication systems pose the challenge of their tolerance to linear and non-linear fiber impairments. Coherent optical receivers using digital signal processing techniques can mitigate the fiber impairments in the optical transmission system, including the chromatic dispersion equalization with digital filters. In this paper, an adaptive finite impulse response filter employing normalized least mean square algorithm is developed for compensating the chromatic dispersion in a 112-Gbit/s polarization division multiplexed quadrature phase shift keying coherent communication system, which is established in the VPI simulation platform. The principle of the adaptive normalized least mean square algorithm for signal equalization is analyzed theoretically, and at the meanwhile, the taps number and the tap weights in the adaptive finite impulse response filter for compensating a certain fiber chromatic dispersion are also investigated by numerical simulation. The chromatic dispersion compensation performance of the adaptive filter is analyzed by evaluating the behavior of the bit-error-rate versus the optical signal-to-noise ratio, and the compensation results are also compared with other present digital filters.     

高灵敏度等时性回旋加速器束流相位测量系统

介绍了兰州重离子加速器（HIRFL）束流相位测量装置。该装置的研制基于双平衡混频原理，利用了高频信号混频滤波技术，具有较高的测量灵敏度。通过安装在加速器中的容性感应探针探测等时性回旋加速器束流相位历程，对于调束中获取等时场信息并对磁场进行优化,从而提高引出束流强度和束流品质是非常重要的。该装置通过等时场相位优化实验，检验了相位测量数据的可靠性，测量精度达到±0.5°。     

同时获得高亮度检测场和高衬比条纹的实时全息记录方法

讨论了实时全息法应用于检测透明物体的情况下获得高衍射效率和高衬比条纹的若干问题。给出了同时获得高亮度检测场和高衬比条纹的最佳参数。在最佳光束比等于１和最佳相位调制度为１．４２时,衍射效率和光能利用率均可达到２９％。     

UV filter 2‐ethylhexyl 4‐methoxycinnamate: a structure,energetic and UV–vis spectral analysis based on density functional theory

2‐Ethylhexyl 4‐methoxycinnamate (EHMC) is a very commonly used UVB filter that is known to isomerize from the (E) to the (Z) isomer in the presence of light. In this study, we have performed high level quantum chemical calculations using density functional theory (DFT) with the B3LYP density functional and extended basis sets to study the gas‐phase molecular structure of EHMC and its energetic stability. Calculations were also performed for related smaller molecules cinnamic acid and 4‐methoxycinnamic acid. Charge delocalization has been analyzed using natural charges and Wiberg bond indexes within the natural bond orbital analysis and using nucleus independent chemical shifts. Density functional theory calculations reveal that the (E) isomer of EHMC is more stable than the (Z) by about 20 kJ mol^?1 in both the gas and aqueous phases. The enthalpy of formation in the gas phase of (E)‐EHMC was derived from an isodesmic bond separation reaction. Long‐range corrected DFT calculations in implicit water were made in order to understand the excited state properties of the (E) and (Z) isomers of EHMC. Copyright © 2013 John Wiley & Sons, Ltd.     

Inequalities for the Casorati Curvature of Totally Real Spacelike Submanifolds in Statistical Manifolds of Type Para-Kähler Space Forms

The purpose of this article is to establish some inequalities concerning the normalized δ-Casorati curvatures (extrinsic invariants) and the scalar curvature (intrinsic invariant) of totally real spacelike submanifolds in statistical manifolds of the type para-Kähler space form. Moreover, this study is focused on the equality cases in these inequalities. Some examples are also provided.     

Final state effect for Au 4f line from gold-nano-particles grown on oxides and HOPG supports

The effect of a positive charge left to a small metal particle immediately after photoemission, so called the final state effect is studied for Au 4f binding energy (E_B) shifts. The size and shape of Au nano-particles were determined by high-resolution medium energy ion scattering combined with scanning electron microscopy of a field emission type. The shape of Au nano-particles is well approximated by a partial sphere with diameter d and height h. It is found that the E_B shift is well expressed as number of atoms per particle (n_A) and independent of support species. The E_B shift changes dramatically at a critical n_A value of ∼70 atoms, where metal-nonmetal transition takes place. In the nonmetal region, the E_B shift increases steeply almost exponentially with decreasing n_A and in contrast, gradually decreases with increasing n_A in the metallic region. The effect of the positive charge of an Au 4f vacancy created by photoemission is expressed by the relaxation time τ and the effective charge +αe when the photoelectron just leaves the Au particle surface (e: electron charge, α < 1).     

Rapid determination of the RF pulse flip angle and spin-lattice relaxation time for materials imaging

For samples with T1s longer than 10s, calibration of the RF probe and a measurement of T1 can be very time-consuming. A technique is proposed for use in imaging applications where one wishes to rapidly obtain information about the RF flip angle and sample T1 prior to imaging. The flip angle measurement time is less than 1s for a single scan. Prior knowledge of the RF flip angle is not required for the measurement of T1. The resulting time savings in measuring the values of flip angle and T1 are particularly significant in the case of samples with very long T1 and short T2*. An imaging extension of the technique provides RF flip angle mapping without the need for incrementing the pulse duration, i.e., RF mapping can be performed at fixed RF amplifier output.     

Interrelation between electronic structure and interatomic distances for compounds

The heat capacity was studied for LaMn₂Si₂, La_0.75Y_0.25Mn₂Si₂, La_0.7Y_0.3Mn₂Si₂, YMn₂Si₂ and LaFe₂Si₂ isostructural intermetallic compounds in the temperature range 1.8–360 K. The electronic, magnetic and lattice contributions to the heat capacity of the compounds were determined and analyzed. The interrelation was found between values of the electronic contribution to the heat capacity (density of states at the Fermi level) and crystal lattice parameters of R(Mn,Fe,Ni)₂Si₂ compounds. The electronic contribution and the density of states at Fermi level increase with increasing lattice parameters of the compounds. The change of interlayer Mn–Mn exchange interactions with change of Y concentration in La_1-xY_xMn₂Si₂ compounds is not accompanied by considerable changes in the electronic contribution to the heat capacity and density of states at the Fermi level. The performed analysis of the magnetic contribution shows that no essential differences exist between the behavior of the heat capacity of the compounds with d_Mn–Mnd_c and with d_Mn–Mn<d_c upon various types of the magnetic phase transitions.