NONLINEAR OPTICAL EFFECTS INDYE-DOPED NEMATIC LIQUID CRYSTAL DROPLET MATERIALS

对布满液晶微粒的聚合物(ＰＤＬＣ)进行了简并四波混频及光学双稳态的研究,并在文中对相关的ＰＤＬＣ中的分子重取向和热效应的非线性光学效应进行了讨论．Optical bistability and degenerate four-wave mixing arrangement in polymer dispersed liquid crystal (PDLC) droplets were studied. Both re-orientational and thermal nonlinearities of PDLC were discussed by using the concepts presented in the paper

Measurement of Tide Variation of the Earth with Laser Double Beam Interference Mathod

本文提出利用激光双光束干涉方法研究地球潮的变化，对其测量原理和测量精度作了分析、讨论。通过对干涉条纹进行调制并计数，在激光波长为0.63μM时，对25M的测量精度可达1/100干涉级次（0.006μM）。因此，在隧道中用这个方法可测地球潮。In this paper,the measurement of tide variation of the earth has been studied by using laser double beam Interference method.We have discussed the measuring principle and precision.The results show that the precision is of 0.006 m at =6 328,length 25 m by modulating and counting of interferogram.So the mathod may be used to measure the tide variation of the earth in tunnel.福建省自然科学基

Optical Bistability of EBBA Liquid Crystal

利用光自聚焦和f-P腔两种手段，对EbbA液晶进行了光学双稳态研究。实验是在60μM液晶薄膜中采用连续Ar＋激光器进行，确定出温度与光学双稳态和多级光学双稳态回线的关系，讨论了EbbA液晶在固态相和液晶相及其相变过程中光学双稳态的机制。Using self focusing and Fabry Perot cavity arrangements,the optical bistability and multiple bistability of EBBA nematic liquid crystal films have been studied.The experiment was carried out with Ar + CW laser and samples of 60 μm thickness.The temperature dependence of the bistable and multiple bistable loops has been measured.The related mechanism of optical bistability in solid phase,nematic phase and phase transition of liquid crystalb.国家自然科学基金;福建省自然科学基

液晶低功率热光双稳态的研究

液晶低功率热光双稳态的研究周海光，陈书潮，吴河浚（厦门大学物理系，厦门361005）1987年，HuTCHIng提出将介质充满f-P腔中，与f-P腔反射面直接接触，利用f-P腔反射面的吸收，并将热量传到介质中从而产生热光双稳态，其临界人射功率可以下降..

支撑应力对骨小梁分布的影响及股骨头坏死因素的研究

目的通过犬股骨颈骨折螺钉内固定模型的力学检测及组织学观察,从微观角度认识骨小梁重建对股骨头坏死的影响。方法选取18只成年田园犬制作成股骨颈骨折螺钉内固定模型,于造模后12周确认所有股骨颈骨折已愈合随机分为取钉组、取钉植骨组及不取钉组,于造模后20周分离所有犬的股骨并进行股骨颈力学测试及组织学观察。结果取钉组、取钉植骨组及不取钉组断裂点载荷、最大载荷差异有统计学意义(P0.05),不取钉组与取钉植骨组断裂点载荷大于取钉组;不取钉组最大载荷大于取钉植骨组与取钉组,取钉植骨组最大载荷大于取钉组。取钉组、取钉植骨组及不取钉组骨小梁宽度与新鲜骨面积差异有统计学意义(P<0.05);不取钉组骨小梁宽度、新鲜骨面积大于取钉植骨组,且取钉植骨组大于取钉组。结论支撑应力的改变将导致骨小梁重新分布,骨小梁再分布是影响股骨头坏死塌陷的重要因素。福建省卫生系统中青年骨干人才培养项目(2014-ZQNJC-34

A DDA Calculation on the Optical Properties of Silver Nanorods

【中文文摘】利用离散偶极近似 (Discretedipoleapproximation ,简称DDA)的方法 ,从理论上对粒子的形状、尺寸及周围介质等因素对银纳米粒子 ,特别是银纳米棒的光学性质的影响进行了较系统的研究 .计算表明 ,置于空气中的棒状银纳米粒子的光学性质与其形状密切相关 ,纵向表面等离子体共振吸收峰的位置随纳米棒长径比的增加呈现线性红移关系 .给出了空气中银纳米棒纵向表面等离子体共振吸收峰的位置随长径比变化的DDA拟合公式 .如果将金属纳米粒子置于折射率更高的介电环境中 ,其纵向等离子体共振吸收峰的位置进一步呈现线性红移关系 .合成的银纳米粒子的TEM图像及相关的UV VIS消光光谱显示DDA计算结果与实验值相当一致 .DDA算法与Mie′s理论在计算球状银纳米粒子的消光系数时给出很接近的结果 ,这表明用DDA的方法来分析银的光学性质是准确可靠的 ;而DDA算法对银纳米棒消光特性的成功拟合则表明 ,该算法相对Gans′理论而言 ,在研究纳米粒子的光学性质时具有更广的适用性及更高的准确性 . 【英文文摘】The optical properties of metal nanoparticles are quite different from those of the bulk materials mainly due to the collective oscillations of their conduction electrons known as the surface plasmon resonance (SPR), which is strongly dependent on the particle shape and size, and the dielectric properties of the local environment where the nanoparticles are embedded in. Based on the discrete dipole approximation (DDA) method, we studied the optical properties of silver nanorods with different aspect ratios ...Project supported by the National Natural Science Foundation of China (2 0 2 2 80 2 0,2 0 0 2 10 0 2

The Size and Shape Effects on the Optical Properties of Gold Nanoparticles

【中文文摘】纳米尺度的金属及半导体呈现出特殊的光学、电学及磁学性质,采用近年发展起来的离散偶极近似(DDA)的方法,我们分析了金纳米粒子的尺寸及形状对其光学性质的影响。粒子周围介质的影响在文中亦作了分析。计算结果显示,金纳米粒子的等离子体吸收带同时受到粒子尺寸和形状的影响,但来自形状的影响更为明显。与米氏理论及扩展的甘氏理论相比较,DDA方法在粒子尺寸不再远小于入射光波长的时候更准确,并能应用于任何形状的纳米粒子。理论计算与实验结果能较好的吻合。 【英文文摘】Metals and semiconductors exhibit unusual optical, electronic, and magnetic properties at the nanometer scale. Based on the newly developed method, discrete dipole approximation (DDA), the dependence of the optical properties of the gold nanoparticles on the size and shape was analyzed. The effects of the surrounding medium were also taken into consideration in the calculation. The calculated results show that the plasmon absorption band depends on both the size and shape of the gold noanoparticles. However , the influence of the shape is more significant . Compared to the Mieps theory and the extension , Gansp theory , the DDA method is more accurate when the dimensions of the particles are not much smaller than the wavelength of the incident light and can be applied to particles of any shape. The theoretical results are in good agreement with the experimental data.国家自然科学基金项目,批准号为 :20003008,2983306

The catalytic esterification properties of PVA membranes filled with ironic sulfate

［中文文摘］通过在PVA膜中掺杂硫酸铁制得兼备催化和分离功能的酯化膜反应器 ,并用IR、DSC及SEM等测试方法分析了膜的形态结构及组成。实验结果表明 :硫酸铁的加入对膜的渗透性能和酯化反应的选择性及转化率的提高有重要作用 ;对于乙酸 /乙醇酯化反应体系 ,适宜的填充量为 2 0 %～ 30 % (质量比 )。［英文文摘］The membranes with both catalytic and separative properties were made by using the　hydrophilic alcohol (PVA) filled Lewis acid Ironic sulfate. The chemical composition , physical structure and morphology were studied by a variety of techniques , including infrared　spectrometry( IR) , differential scanning calorimeter (DSC) and scanning electron microscopy (SEM) etc. The experimental results showed that the addition of Fe3 (SO4) 2 was inportant to improve the flux of the membrane flux and the yield and selection of the esterification reac2tion , and the appropriate cotent of Fe3 (SO4) 2 for the alcohol/ acid esterification was 20 %～30 %(w/ w) .福建省自然科学基金 (C991 0 0 0 3) ；教育部骨干教师基金；教育部重点科技项目；教育部留学回国人员启动费资助

Antioxidant Tannins from Stem Bark and Fine Root of Casuarina equisetifolia

Structures of condensed tannins from the stem bark and fine root of Casuarina equisetifolia were identified using MALDI-TOF MS and HPLC analyses. The condensed tannins from stem bark and fine root consist predominantly of procyanidin combined with prodelphinidin and propelargonidin, and epicatechin is the main extension unit. The condensed tannins had different polymer chain lengths, varying from trimers to tridecamer for stem bark and to pentadecamer for fine root. The antioxidant activities were measured by two models: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing/antioxidant power (FRAP). The condensed tannins extracted from C. equisetifolia showed very good DPPH radical scavenging activity and ferric reducing/ antioxidant power, suggesting that these extracts may be considered as new sources of natural antioxidants for food and nutraceutical products.Special Prophase Project on National Basic Research Program of China (973 Program) [2009CB426306]; National Eleventh-Five Year Key Project [2009BADB2B0302]; Program for New Century Excellent Talents in University [NCET-07-0725