Enhancement of confocal microscopy images using Mueller-matrix polarimetry

A simplified procedure based on Mueller-matrix polarimetry has recently been reported as a method of retinal image improvement in a confocal ophthalmoscope [J. M. Bueno et al ., J. Opt. Soc. Am. A 24, 1337 (2007)]. Here, we have applied the technique to imaging static samples providing well-defined reflection properties. The method uses a generator of polarization states in the illumination pathway of a confocal scanning laser system. From the calculated four elements of the Mueller matrix of any sample and instrument combination, the best images defined by different metrics were constructed. For samples with specular, diffuse and mixed reflections, the best-constructed images showed an enhancement in both objective and subjective image quality compared to the original images and those obtained from frame averaging. This technique could improve microscopic imaging in many diverse fields, particularly in biomedical imaging.     

化学拆分法制备D-2-氨基丁醇

以酒石酸为拆分剂,从外消旋2-氨基丁醇中拆分出（ D）-2-氨基丁醇和（ L）-2-氨基丁醇。考察了不同的溶剂对2-氨基丁醇拆分的影响,最终选取了正丁醇作为拆分溶剂。并对反应时间,反应温度,溶剂体积对拆分的影响进行了考察。在最优条件下, D-2-氨基丁醇的总收率达到83.69％,旋光达到9.9°。     

Polarimetric Borehole Radar System for Fracture Measurement

Radar polarimetry is a technology that overcomes the limitation between the radar resolution and the penetration depth of borehole radar. We have developed a stepped-frequency polarimetric borehole radar system. This is a polarimetric borehole radar system which measures the full-radar polarimetry in a borehole by changing the antenna arrangements. By using a network analyzer and an optical analog signal link, this system has a frequency bandwidth of 2–500MHz, which is suitable for two different antennas for radar polarimetry. We also propose a technique for polarimetric antenna calibration. In order to understand the potential of polarimetric borehole radar, field measurement were carried out at the Mirror Lake fractured-rock research site (NH, USA). The radar penetration depth from the borehole in the reflection measurement was over 10m, at the frequency range of 2–402MHz. We observed many clear reflections from fractures in each polarization status. Even in the raw data, we found the differences in the radar profile for different polarization status. We believe the polarimetric feature is closely related to the roughness of each fracture, and it is also related to the physical properties of the fracture such as water permeability.     

Impact of edge localized mode on photo-elastic-modulator based motional Stark effect polarimetry

Intermittent increase in background light induced by edge localized mode (ELM) in high confinement mode (H-mode) plasma gives disturbances to polarization angle of incident light measured by motional Stark effect (MSE) polarimeter using photo-elastic modulator (PEM), even if the background light is not polarized. The error in the polarization angle γ_PEM determined by the light intensity at the frequency modulated by the PEM originates in a broadband frequency spectrum of the intermittent background light and applies to PEM based polarimeter in general. The impact of the background light induced by the ELM on the error in γ_PEM is numerically investigated in terms of the polarization angle of incident light γ, the peak intensity of background light normalized by the intensity of beam emission X_ELM, ELM frequency f_ELM, ELM decay time τ_ELM and the time constant of low-pass filter (LPF) per single stage τ_LPF. The error increases almost proportionally with γ between ±22.5° when inphase spectral amplitude is used in γ_PEM calculation. The error becomes quite large for γ approaching to the direction of PEM axis (±22.5°), when absolute spectral amplitude is used. The error increases with X_ELM but does not depend on τ_ELM. When the ELM frequency is sufficiently lower than a critical ELM frequency that is given by inverse of an effective LPF time constant (τ_LPF times the number of LPF stages), the error has its peak, the height of which is independent of f_ELM, soon after the ELM and vanishes between subsequent ELMs. However, when f_ELM is higher than the critical ELM frequency, errors induced by subsequent ELMs pile up and the error increases with f_ELM. In case of no pileup, the maximum error becomes larger for smaller τ_LPF, because impact of ELM temporally concentrates in a shorter period just after the ELM. The error induced by ELMs is roughly estimated to be ∼0.002° in a type-I ELMy H-mode JT-60U discharge, which is much smaller than other errors coming from calibrations (about 0.1-0.2°) and temporal fluctuation (less than about 0.05°), mainly since the background light induced by ELMs is weak compared to the beam emission X_ELM ∼0.07 in JT-60U. However, MSE diagnostics experiencing large background light (X_ELM) should take this kind of error into account.     

A simple and rapid polarimetric method for quantitative determination of castor oil

A simple and rapid polarimetric method is developed for quantitation of adulteration of castor oil in edible oils such as cottonseed, coconut, mustard, olive, palm, peanut, rice bran, safflower, soybean, and sunflower. The method is based on the optical activity of ricinoleic acid (12-hydroxy octadecenoic acid), a major constituent of castor oil. There is a good correlation between optical rotation and castor oil content in admixtures above 5%. Highly colored and viscous oils interfere in the measurement of optical activity. The method is highly specific and cost-effective. No solvents and chemicals are required for the analysis because no sample processing is involved in the present method.     

薄膜多参数测量系统设计及实验

设计薄膜多参数测量系统,对薄膜在制备后膜厚、厚度分布及薄膜残余应力等表征薄膜制备效果的参数同时进行测量,减少测量误差。通过分析椭偏测量、光谱测量和激光测量技术,设计薄膜多参数测量系统,并搭建测量系统。为验证该系统,通过RC2和设计系统对不同厚度的薄膜和薄膜进行测量对比实验,表明设计系统对不同薄膜厚度的测量偏差均小于0.3 nm,厚度分布测量偏差值小于0.06%;通过ZYGO激光干涉仪和设计系统对不同直径的薄膜进行对比测试实验,表明该系统的测量偏差在以内。测量系统能够满足薄膜制备后对不同参数同时测量的测量需求,简化了测量过程。     

近红外旋光法检测食糖的蔗糖分

目的 建立一种近红外旋光法测定食糖的蔗糖分。方法 通过配制纯蔗糖溶液,确定在589.44 nm（589 nm）和880.00 nm（880 nm）波长下蔗糖溶液酸水解前后旋光度差值的比值,基于普通旋光法（国家标准）推导出近红外旋光法计算蔗糖分公式,并将测定结果进行比对。结果 在589 nm和880 nm波长下蔗糖溶液酸水解前后旋光度差值的比值为2.333,在蔗糖分为50%~100%时,近红外旋光法线性关系良好,回收率为98.9%~100.1%,相对标准偏差为0.043%~0.064%,与普通旋光法比对结果一致。结论 该方法灵敏、准确,具有良好的重复性和稳定性,应用范围广,可用于食糖的蔗糖分检测。