Design of non-polarizing thin film edge filters

The separation between s- and p-polarization components invariably affects thin film edge filters used for tilted incidence and is a difficult problem for many applications, especially for optical communication. This paper presents a novel design method to obtain edge filters with non-polarization at incidence angle of 45°. The polarization separation at 50% trans-mittance for a long-wave-pass filter and a short-wave-pass filter is 0.3 nm and 0.1 nm respectively. The design method is based on a broadband Fabry-Perot thin-film interference filter in which the higher or lower interference band at both sides of the main transmittance peak can be used for initial design of long-wave-pass filter or short-wave-pass filter and then can be refined to reduce the transmittance ripples. The spacer 2H2L2H or 2L2H2L of the filter is usually taken. Moreover, the method for expanding the bandwidth of rejection and transmission is explained. The bandwidth of 200 nm for both rejection region and transmission band is obtained at wavelength 1550 nm. In this way, the long-wave-pass and short-wave-pass edge filters with zero separation between two polarization components can easily be fabricated.

Effects of Ⅴ/Ⅲ ratio on species diffusion anisotropy inthe MOCVD growth of non-polar a-plane GaN films

Non-polar a-plane （1120） GaN films have been grown on r-plane （1102） sapphire substrates by metal organic chemical vapour deposition. The influences of V/III ratio on the species diffusion anisotropy of a-plane GaN films were investigated by scanning electron microscopy, cathodoluminescence and high-resolution x-ray diffraction measurements. The anisotropy of a-plane GaN films may result from the different migration length of adatoms along two in-plane directions. V/III ratio has an effect on the growth rates of different facets and crystal quality. The stripe feature morphology was obviously observed in the film with a high V/III ratio because of the slow growth rate along the [1100] direction. When the V/III ratio increased from 1000 to 6000, the in-plane crystal quality anisotropy was decreased due to the weakened predominance in migration length of gallium adatoms.

Theoretical analysis of semi/non-polar In GaN/GaN light-emitting diodes grown on silicon substrates

A theoretical study of polar and semi/non-polar InGaN/GaN light-emitting diodes（LEDs） with different internal surface polarization charges, which can be grown on Si substrates, is conducted by using APSYS software. In comparison with polar structure LEDs, the semi-polar structure exhibits a higher concentration of electrons and holes and radiative recombination rate, and its reduced built-in polarization field weakens the extent of band bending which causes the shift of peak emission wavelength. So the efficiency droop of semi-polar InGaN/GaN LEDs declines obviously and the optical power is significantly improved. In comparison with non-polar structure LEDs, although the concentration of holes and electrons as well as the radiative recombination rate of the semi-polar structure are better in the last two quantum wells（QWs） approaching the p-Ga N side, the uniformity of distribution of carriers and radiative recombination rate for the nonpolar structure is better. So the theoretical analysis indicates that the removal of the internal polarization field in the MQWs active regions for non-polar structure LEDs contributes to the uniform distribution of electrons and holes, and decreases the electron leakage. Thus it enhances the radiative recombination rate, and further improves the IQEs and optical powers, and shows the best photoelectric properties among these three structures.

Broadband non-polarizing beam splitter based on guided mode resonance effect

A broadband non-polarizing beam splitter （NPBS） operating in the telecommunication C＋L band is designed by using the guided mode resonance effect of periodic silicon-on-insulator （SOI） elements. It is shown that this double layer SOI structure can provide ~50/50 beam ratio with the maximum divergences between reflection and transmission being less than 8% over the spectrum of 1.4μm-l.7 μm and i% in the telecommunication band for both TE and TM polarizations. The physical basis of this broadband non-polarizing property is on the simultaneous excitation of the TE and TM strong modulation waveguide modes near the designed spectrum band. Meanwhile, the electric field distributions for both TE and TM polarizations verify the resonant origin of spectrum in the periodic SOI structure. Furthermore, it is demonstrated with our calculations that the beam splitter proposed here is tolerant to the deviations of incident angle and structure parameters, which make it very easy to be fabricated with current IC technology.

The Up-conversion Laser Properties of a Non-polar Organic Dye and the Influence of Solvents and Pumping Wavelengths

A non-polar organic dye, E, E-1, 4-bis[4＇-（N,N-dibutylamino）styryl]-2,5-dimethoxybenzene （DBASDMB）, has been synthesized and characterized, and its structure has been determined. Pumped with a 200fs pulse this dye showed the up-conversion laser properties. The influences of various organic solvents and different pumping wavelength on the laser properties have been demonstrated.

Study on Surface Properties for Non-polar Fluids with Density Functional Theory

The density functional theory, simplified by the local density approximation and mean-field approxi-mation, is applied to study the surface properties of pure non-polar fluids. A reasonable long rang correction is adopted to avoid the truncation of the potential. The perturbation theory is applied to establish the equation for the phase equilibrium, in which the hard-core chain fluid is as the reference fluid and the Yukawa potential is used as the perturbation term. Three parameters, ε/κ, d and ms, are regressed frorn the vapor-liquid equilibria, and the surface properties, including density profile, surface tension and local surface tension profile are predicted with these parameters.

Evaluation of the Equality of Non-Polar Capillary Columns in GC/MS Analysis of Food Contact Plastics

Non-polar capillary columns for GC/MS are widely utilized in the analysis of additives for food contact materials. Though various kinds of non-polar capillary columns are commercially available, the equality of their performance has not been verified. Herein, ninety-six additives for food contact plastics were analyzed using fifteen kinds of columns, and the peak separation, retention times, and peak areas of each additive were compared. The additives, with various chemical properties, comprised forty four plasticizers, twenty lubricants, twenty antioxidants, nine ultraviolet absorbers, and three other compounds. 10 μg.mL-1 test solutions were prepared in acetone, and injected to the GC/MS. The fifteen columns were classified into five categories based on the chromatogram pattern and peak separation. To facilitate comparison of the retention time and detection sensitivity of the columns for the additives, the relative retention time (RRT) and relative peak area (RPA) were calculated by using dibutylphthalate or 4-tert-butylphenylsalicylate as an internal standard. The RRTs of the additives on each column were essentially similar. However, the RRT of the additives which were detected in the later stages differed slightly. Although the RPA of the plasticizers and lubricants were roughly similar, column-to-column differences were observed for certain additives, such as antioxidants and ultraviolet absorbers. Furthermore, certain fatty acids, antioxidants, two plasticizers, and two benzophenone type ultraviolet absorbers were not detected in the chromatograms of two columns.

Effect of Kombucha and Its Non-Polar Components on Morphological Aspects of the Pancreas of Diabetic Rats with Streptozotocin

Objective: to evaluate the protective effect of kombucha and its components not polar, in pancreas of diabetic rats treated with streptozotocin. Material and methods: ninety-six male Wistar rats of 120 to 170 g of PC were used;four groups of 24 animals were formed: control (GC), control treatment (GCTx), kombucha treatment (GTxK) and treatment with non-polar components of kombucha (GTxCNP). Diabetes was induced in the last three groups with an intraperitoneal injection of streptozotocin at a dose of 65 mg/kg BW. At the same time, treatment was started in the different groups;GC and GCTx groups were administered, orally, 1 ml of sterile saline solution;to the GTxK group 324 mg/kg of kombucha;and to GTxCNP 0.006 mg/kg of the non-polar components. For the histopathological study, pancreas samples were obtained on days 1, 7, 14 and 21 and fixed in formalin. They were processed with the histological technique, 5-micron-thick sections were made and stained with the hematoxylin-eosin technique. Finally, the number of islets of Langerhans per field observed with the 10x objective was quantified. The results were subjected to a one-way analysis of variance and Tukey’s test (p Results: Significant changes in the number of islets were observed in histological sections of the pancreas. The groups treated with streptozotocin showed a significant decrease in the number of islets 7 days after starting treatment;Likewise, their number was lower in the GCTx group compared to the GTxK and GTxCNP groups (p ≤ 0.05). At 14 and 21 days, the lowest number of islets was maintained, although only in the GCTx and GTxK groups (p ≤ 0.05). Streptozotocin is a drug that can be used in rats to induce an experimental model of diabetes with an effect that can last up to 21 days. Conclusions: This fermented beverage and its non-polar components can be a complementary treatment alternative for diabetes mellitus, since it prevents further damage to the β cells of the pancreas and the Islets of Langerhans. Specific additional studies on the main, non-polar components of kombucha are suggested to know the mechanism of protection on pancreatic islets.

Morphological and Microstructural Evolution and Related Impurity Incorporation in Non-Polar a-Plane GaN Grown on r-Sapphire Substrates

Effects of the growth temperature on morphological and microstructural evolution of a-plane GaN films grown on r-plane sapphires by metal organic chemical vapor deposition are investigated by atomic force microscopy and secondary ion mass spectroscopy （SIMS）. Surface morphology, structural quality and related impurity incorpora- tion are very sensitive to the growth temperature. A significant difference of yellow luminescence is observed and attributed to the incorporation of carbon into GaN films, which is confirmed by SIMS analysis. Our results show that the sample with triangular-pit morphology has sample with pentagon-like pit morphology, which is significantly higher concentrations of oxygen than the other induced by the existence of an N-face in triangular pits.

采用非稳相偏振滤波的DAS-VSP数据P/S波分离方法及其应用

分布式光纤声学传感(DAS)因成本低、易布设以及高密度采样等优势正成为重要的地震观测技术,尤其是越来越多地与垂直地震剖面(VSP)结合,用于主动地震勘探或被动地震监测.DAS传感器通过感知弹性波场产生的轴向应变或应变速率来观测地震波场振动.然而,目前单分量DAS-VSP数据未完整地记录地下弹性波场的三维矢量振动信号,因此如何从中分离出P波或S波用于后续地震成像与参数反演是重要且很有挑战的课题.以弹性波传播理论为基础,本文根据P波和S波的频散关系估算接收点处各自的偏振方向,通过随频率和空间位置变化的偏振滤波实现DAS-VSP数据的P/S波分离.理论模型合成数据与东海实际DAS-VSP数据实验结果表明,该方法能有效地将P波和S波信号从单分量DAS-VSP数据中分离出来,可为后续纵横波速度反演、PP与PS波成像提供关键的数据预条件处理.

低阶煤表面润湿性调控对油类捕收剂铺展的影响

为阐明浮选过程中低阶煤表面润湿性变化对油类捕收剂在煤表面铺展的影响,以哈尔乌素煤为研究对象,通过阳离子表面活性剂十二烷基三甲基溴化铵(DTAB)、阴离子表面活性剂十二烷基硫酸钠(SDS)和非离子表面活性剂脂肪醇聚氧乙烯醚(AEO-4)对煤表面进行润湿性调控,使用原子力显微镜(AFM)对低阶煤表面的非极性捕收剂(煤油)油膜厚度进行直接测量,并对作用机制进行了研究。结果表明:非极性捕收剂在低阶煤表面的铺展与其疏水程度密切相关,经SDS,AEO-4和DTAB处理后捕收剂在低阶煤表面油膜的厚度分别为17.86 nm,18.06 nm,19.85 nm,其中DTAB处理后能够形成具有稳定的有序层和过渡层的双层油膜结构,这表明DTAB更有利于强化非极性捕收剂在低阶煤表面的铺展;在研究范围内,非离子表面活性剂AEO-4质量分数由0.5%增加到2.0%时,低阶煤表面的油膜厚度由10.89 nm增加到19.85 nm,说明表面活性剂质量分数增加可以增强捕收剂分子与低阶煤表面之间的相互作用,同时精煤产率由68.96%提升至70.91%,可燃体回收率由83.92%提升至85.82%,提高了低阶煤浮选效果。

面向地物混杂背景的偏振光谱图像融合方法

针对偏振光谱图像融合方法在地物混杂背景遥感探测中多尺度变换融合图像存在边缘轮廓细节模糊、对比度不佳的问题,提出一种基于非下采样轮廓波变换的稀疏表示与引导滤波器相结合的图像融合方法,以改善融合图像的质量和视觉效果。首先,该方法通过非下采样轮廓波变换对光谱图像和偏振图像进行多尺度多方向分解,进而将图像分解成不同子带内的特征信息。其次,低频子带采用稀疏表示融合,从而降低融合图像中物体对比度损失。此外,采用引导滤波器融合高频子带,以增强图像轮廓细节信息。最后,对低频与高频融合系数进行非下采样轮廓波逆变换,最终得出融合图像。分析表明融合图像对比度相对于原始光谱图像与偏振度图像分别提升了54.5%和15.4%,更容易区分混杂背景下阴影中的物体。基于此方法对偏振光谱成像仪所采集的不同波长下的光谱与偏振图像进行融合,并实现真彩还原。真彩还原图像证明此融合方法在保留混杂背景下的环境信息的同时实现了物体和背景的有效区分,有效提高了偏振光谱遥感探测成像的图像质量,有助于提升偏振光谱遥感探测成像中图像信息的完整性和真实性,扩大其在复杂环境遥感探测和图像识别中的应用范围。

八髎穴齐刺联合红外偏振光治疗急性非特异性下腰痛临床研究

目的:观察八髎穴齐刺联合红外偏振光照射治疗急性非特异性下腰痛的临床疗效。方法:60例急性非特异性下腰痛患者随机分为观察组和对照组,每组各30例。两组患者均使用红外偏振光采用振荡模式照射针刺部位,1次/d;对照组采用常规针刺治疗,观察组采用八髎穴齐刺法针刺治疗,两组均治疗5 d。观察两组的临床疗效,比较两组治疗前后采用视觉模拟评分法(VAS)评价腰腿部疼痛程度,采用Oswestry功能障碍指数(ODI)评价腰椎功能,采用指地距离(FFD)评价腰部主动前屈受限程度,采用健康状况调查问卷SF-36在治疗前后评价患者的生活质量。结果:与治疗前比较,两组VAS评分、ODI评分和FFD评分均明显下降,差异有统计学意义(P<0.05),且观察组评分降低值均显著大于对照组,差异有统计学意义(P<0.05);与治疗前比较,两组SF-36评分明显提高,差异有统计学意义(P<0.05),且观察组评分明显高于对照组,差异有统计学意义(P<0.05)。观察组总有效率为96.67%(29/30),显著高于对照组的80.00%(24/30),两组差异有统计学意义(P<0.05)。两组均未出现明显不良反应。结论:以八髎穴齐刺针刺法联合红外偏振光照射治疗急性非特异性下腰痛疗效显著,在缓解患者疼痛及改善腰部前屈活动方面效果优于常规针刺方式,改善患者生活质量早期疗效明显。

阴阳离子组合捕收剂在低品位锂云母矿浮选回收中的应用及选择性吸附机理研究

针对强酸性矿浆体系(pH=2~3)胺类捕收剂浮选锂云母矿时,存在硫酸耗量高、设备腐蚀严重、浮选泡沫黏度大、废水处理困难等问题,以湖南某含钨锡锂铷多金属矿的钨锡选别尾矿(锂云母浮选给矿,Li_(2)O品位0.44%)为研究对象,在中性矿浆环境和不脱泥条件下,采用阴离子捕收剂WJ和阳离子捕收剂DDA(十二胺)组合对该低品位锂云母矿进行浮选回收,并通过原子力显微镜和芘荧光光谱从微观层面探究了阴阳离子组合捕收剂的协同效应与吸附机理。结果表明:相比单一DDA,采用WJ+DDA组合(质量比3.5∶1),捕收剂用量降低130 g/t,获得的锂云母精矿中Li_(2)O品位提高0.35%,Li_(2)O回收率提高1.41%,且浮选泡沫清爽,脉石夹带少。WJ+DDA组合捕收剂分子更密集地吸附在锂云母表面,而在石英/长石表面基本不发生吸附。相比单一WJ或DDA,WJ+DDA组合捕收剂具有更大的非极性和更强的疏水性,因而具有更高的表面活性。

基于液晶偏振光栅的大口径激光光束扫描系统

非机械式激光光束扫描系统具有体积小、重量轻、易集成等优势,在激光雷达、激光武器和激光通信等领域具有较大的应用前景,其通光口径决定着设备的工作距离、扫描精度和目标摧毁能力。基于液晶偏振光栅设计了一种全电控制的大口径激光光束扫描系统。采用液晶偏振光栅和液晶空间光调制器的协同工作方式,实现光束的大角度连续扫描;设计了光束扫描系统,并重点分析了级联液晶偏振光栅组的控制策略,给出了具体控制方法。最后,进行了激光光束的初步扫描实验,实现了70 mm口径光束在−16.575°~16.575°的偏转。该研究结果为激光光束的非机械式扫描控制提供了技术支撑,并在大口径激光扫描系统应用方面进行了初步探索。

Non-polar Solvent Microwave-Assisted Extraction of Volatile Constituents from Dried Zingiber Officinale Rosc.

A new method, non-polar solvent microwave-assisted extraction （NPSMAE）, was applied to the extraction of essential oil from Zingiber officinale Rosc. in closed-vessel system. By adding microwave absorption mediumcarbonyl iron powders （CIP） into extraction system, the essential oil was extracted by the non-polar solvent （ether） which can be heated by CIP. The constituents of essential oil obtained by NPSMAE were comparable with those obtained by hydrodistillation （HD） by GC-MS analysis, which indicates that NPSMAE is a feasible way to extract essential oil from dried plant materials. The NPSMAE took much less extraction time （5 min） than HD （180 min）, and its extraction efficiency was much higher than that of conventional polar solvent microwave-assisted extraction （PSMAE） and mixed solvent microwave-assisted extraction （MSMAE）. It can be a good alternative for the extraction of volatile constituents from dried plant samples.

Birefringent non-polarizing thin film design

In this paper,2×2 characteristic matrices of uniaxially anisotropic thin film for extraordinary and ordinary wave are deduced at oblique incidence.Furthermore,the reflectance and transmittance of thin films are calculated separately for two polarizations,which provide a new concept for designing non-polarizing thin films at oblique incidence.Besides,using the multilayer birefringent thin films,non-polarizing designs,such as beam splitter thin film at single wavelength,edge filter and antireflection thin film over visible spectral region are obtained at oblique incidence.

基于分焦平面偏振成像的冬青卫矛含水率快速无损检测

针对目前在植物含水率检测中存在的使用场景受限、含水率检测不及时等问题,该研究搭建了一套基于分焦平面偏振相机的偏振成像系统,通过对偏振成像信息的解析建立了线偏振度这一物理量与含水率的依赖关系,揭示了偏振光与植物内水分间的相互作用机理,实现了对冬青叶片含水率的快速、无损检测。结果表明:1)针对于不同月份、晴雨天气条件以及不同部位这3种不同影响因素下的冬青卫矛叶片,都可以通过线偏振度来反映其含水率情况,其统一表现为随着含水率的梯度降低,线偏振度逐渐增大;2)该研究通过采集大量的植物叶片建立预测模型,含水率与线偏振度存在较强的负相关关系,决定系数达到0.85,均方误差仅为0.45%;3)另取叶片对含水率检测模型进行验证,结果表明该模型在含水率检测的验证中均方根误差为4.53%,即可以通过线偏振度表征叶片的真实含水率。该研究成果在推动光学手段在植物健康状态检测的进程中具有应用价值。

引入旋转二面角模型的极化SAR七分量分解方法

在排列方向与传感器飞行方向不平行的建筑物区域(即非平行建筑),常规的二面角散射模型基于反射对称的条件,无法准确描述非反射对称成分的电磁波散射过程,相干矩阵中的T 33项被归因于体散射成分,造成城区建筑物体散射高估的现象。现有极化分解模型大多采用扩展体散射模型的方式来构建倾斜城区非反射对称分量,此类方法能降低建筑物区域体散射,但同时也会导致森林区体散射的低估。从对倾斜城区建筑物建模的角度出发,在不改变已有体散射模型的基础上,提出一种定向角补偿的各向同性二面角模型,该模型能解释极化相干矩阵T 23项的实部,且能描述城区具有不同方位角的建筑物的散射过程。在此基础上,将此二面角散射模型与Singh提出的六分量分解模型相结合,扩展一种新的七分量分解模型。文中选取L波段ALOS-2/PALSAR-2全极化数据,分别在旧金山实验区、长沙实验区进行引入旋转二面角模型的七分量分解实验。实验结果表明,在倾斜的建筑物区域,文中提出的方法能有效改善体散射高估的情况,并能有效地区分倾斜建筑物和森林,对识别和提取城区建筑物具有重要的意义。

基于配位链转移聚合制备反式-1,4-聚丁二烯与聚甲基丙烯酸甲酯嵌段共聚物

使用异丙氧基钕/正丁基镁催化体系催化丁二烯进行高反式-1,4-结构选择性配位链转移聚合,再加入极性单体甲基丙烯酸甲酯制备了反式-1,4-聚丁二烯和聚甲基丙烯酸甲酯的非极性-极性两嵌段共聚物(TPB-b-PMMA),通过凝胶渗透色谱、傅里叶变换红外光谱、核磁共振波谱、原子力显微镜和透射电子显微镜表征了嵌段共聚物TPB-b-PMMA的分子量及其分布、微观结构,以及嵌段共聚物薄膜的表面形貌和微观相态。结果表明,所得嵌段共聚物的凝胶渗透色谱曲线为单峰,分子量分布较窄(多分散性指数小于2.5);嵌段共聚物中反式-1,4-聚丁二烯链段中反式-1,4-结构摩尔分数为95.8%,甲基丙烯酸甲酯结构摩尔分数在10.9%~39.7%范围内可调控;此半结晶嵌段共聚物薄膜具有相分离形态,其圆柱形微区尺寸约为25nm。