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利用有限元分析法结合Fox-Li迭代法,考虑腔内本征模式与腔镜热形变的相互耦合作用,计算模拟了正支共焦非稳腔的本征模式分布,定量分析了高功率激光器腔镜热变形对输出光束质量的影响,重点讨论了腔镜热变形所引起的腔内本征模式相位特性的变化,并从波前功率谱密度、Zernike像差系数及光束质量值等角度对腔镜发生热形变前后的激光器输出光束的光束特性进行比较分析。研究结果表明:高功率激光器腔镜热形变对输出光束的光束质量会产生一定的影响,且随着激光输出功率的增大,镜面热形变引起的输出光束波前相位高频比例及Zernike高阶像差均会有所增大,波前畸变程度也明显变大,光束质量逐渐变差。 相似文献
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采用FFT方法和增益介质近腔镜簿层处理法研究了非稳腔下具有非均匀流动介质的高功率气体激光器的光束特性和光束质量,证实了该方法在小扰动、低放大率、低增益器件的腔型中是适用的。 相似文献
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用增益介质多层分布法模拟非稳腔光束特性 总被引:4,自引:1,他引:3
采用FFT方法和多层增益介质模块处理法研究了非稳腔下具有非均匀流动介质的高功率气体激光器的光束特性和光束质量,该方法比增益介质近腔镜簿层处理法适用性更广。 相似文献
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蒋东镔徐美健胡东霞段文涛蒋新颖於海武 《强激光与粒子束》2008,(8):1257-1260
为改善光束远场质量,探索研究了角锥反射器的应用,利用角锥棱镜的准相位共轭特性,将角锥棱镜阵列作为热容激光器的后腔镜,抑制腔内波前畸变,并通过数值模拟计算对角锥阵列的单元边长进行优化设计。实验结果表明:角锥阵列对光束远场质量有明显的改善,当角锥阵列的单元边长为4 mm时,实现光束远场7倍衍射极限输出。 相似文献
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《中国光学》2019,(3)
为了获得高光束质量的脉冲固体激光输出,研究了高斯非稳腔固体激光器的模式分布。运用边界有限元法将谐振腔内光场衍射积分方程转化成矩阵方程组,模拟分析了平凸高斯非稳腔内光阑位置、孔径大小以及高斯镜参数对输出光束模式的影响。基于理论模拟结果对激光器结构参数进行了优化,分别测量了腔内不同光阑位置和孔径下的激光器输出光束振幅及模式分布情况。在光阑半径为1 mm、光阑距高斯镜为150 mm、泵浦电压为900 V的实验条件下,光束质量M_x~2=1. 9、M_y~2=2. 3,激光最大输出能量为280 mJ的高光束质量激光输出。实验结果表明,在腔内加入选模光阑以及优化高斯镜参数可以进一步改善腔内模式分布,获得高光束质量激光输出,这与理论模拟结果基本相符。 相似文献
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张淑芳 《光谱学与光谱分析》2006,26(3):535-538
提出了运用吸光度比值-导数光谱法同时测定Cr(Ⅲ)与Cu(Ⅱ)含量的新方法。在pH 5.7的HAc-NaAc的缓冲溶液中,Cr3+,Cu2+与铬天青S(CAS)和溴化十六烷基三甲胺(CTMAB)可分别形成蓝色三元络合物。其摩尔吸光系数分别为2.52×105 L·mol-1·cm-1和1.01×105 L·mol-1·cm-1。Cu2+和Cr3+的浓度分别在0.08~1.2 μg·mL-1和0.05~0.52 μg·mL-1范围内符合比尔定律,其检测限分别为0.014和0.013 μg·mL-1。此方法应用于环境水中Cr(Ⅲ),Cu(Ⅱ)的同时测定,取得了满意的结果。 相似文献
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Kurkijärvi JE Nissi MJ Rieppo J Töyräs J Kiviranta I Nieminen MT Jurvelin JS 《Magnetic resonance imaging》2008,26(5):602-607
The depth-wise variation of T(2) relaxation time is known to reflect the collagen network architecture in cartilage, while the delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC) technique is sensitive to tissue proteoglycan (PG) concentration. As the cartilage PG content varies along the tissue depth, the depth-dependent accumulation of the contrast agent may affect the inherent T(2) of cartilage in a nonconstant manner. Therefore, T(2) and dGEMRIC are typically measured in separate MRI sessions. In the present in vitro MRI study at 9.4 T, depth-wise T(2) profiles and collagenous zone thicknesses as determined from T(2) maps in the absence and presence of Gd-DTPA(2-) (T(2) and T(2Gd), respectively) were compared in samples of intact human articular cartilage (n=65). These T(2) measures were further correlated with birefringence (BF) of polarized light microscopy (PLM) to quantify the ability of MRI to predict the properties of the collagen fibril network. The reproducibility of the T(2) measurement in the current setup was also studied. Typical tri-laminar collagen network architecture was observed both with and without Gd-DTPA(2-). The inverse of BF (1/BF) correlated significantly with both T(2) and T(2Gd) (r=0.91, slope=0.56 and r=0.90, slope=0.63), respectively. The statistically significant linear correlations between zone thicknesses as determined from T(2) and T(2Gd) were r=0.55 (slope=0.49), r=0.74 (slope=0.71) and r=0.95 (slope=0.94) for superficial, middle and deep tissue zones, respectively. Reproducibility of the T(2) measurement was worst for superficial cartilage. Consistent with PLM, T(2) and T(2Gd) measurements reveal highly similar depth-dependent information on collagen network in intact human cartilage. Thus, dGEMRIC and T(2) measurements in one MRI session are feasible for intact articular cartilage in vitro. 相似文献
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Rathore RK Gupta RK Agarwal S Trivedi R Tripathi RP Awasthi R 《Magnetic resonance imaging》2011,29(8):1088-1100
The study was aimed to test the feasibility of utilizing an algorithmically determinable stable fiber mass (SFM) map obtained by an unsupervised principal eigenvector field segmentation (PEVFS) for automatic delineation of 18 white matter (WM) tracts: (1) corpus callosum (CC), (2) tapetum (TP), (3) inferior longitudinal fasciculus (ILF), (4) uncinate fasciculus (UNC), (5) inferior fronto-occipital fasciculus (IFO), (6) optic pathways (OP), (7) superior longitudinal fasciculus (SLF), (8) arcuate fasciculus (AF), (9) fornix (FX), (10) cingulum (CG), (11) anterior thalamic radiation (ATR), (12) superior thalamic radiation (STR), (13) posterior thalamic radiation (PTR), (14) corticospinal/corticopontine tract (CST/CPT), (15) medial lemniscus (ML), (16) superior cerebellar peduncle (SCP), (17) middle cerebellar peduncle (MCP) and (18) inferior cerebellar peduncle (ICP). Diffusion tensor imaging (DTI)-derived fractional anisotropy (FA) and the principal eigenvector field have been used to create the SFM consisting of a collection of linear voxel structures which are grouped together by color-coding them into seven natural classes to provide PEVFS signature segments which greatly facilitate the selection of regions of interest (ROIs) for fiber tractography using just a single mouse click, as compared with a manual drawing of ROIs in the classical approach. All the 18 fiber bundles have been successfully reconstructed, in all the subjects, using the single ROIs provided by the SFM approach, with their reproducibility characterized by the fact that the ROI selection is user independent. The essentially automatic PEVFS method is robust, efficient and compares favorably with the classical ROI methods for diffusion tensor tractography (DTT). 相似文献
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White organic light-emitting device with\ both phosphorescent and fluorescent emissive layers
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This paper reports the fabrication of novel white organic light-emitting device(WOLED) by using a high efficiency blue fluorescent dye N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)oN- phenylbenzenamine (N-BDAVBi) and a red phosphoresecent dye bis (1-(phenyl) isoquinoline) iridium (III) acetylanetonate (Ir(piq)2(acac)). The configuration of the device was ITO/PVK:TPD/CBP: N-BDAVBi /CBP/ BALq: Ir(piq)2(acac)/BCP/Alq3/LiF:AL. By adjusting the proportion of the dopants (N-BDAVBi, Ir(piq)2(acac)) in the light-emitting layer, white light with Commission Internationale de l'Eclairage (CIE) coordinates of (0.35, 0.35) and a maximum luminance of 25350cd/m2 were obtained external quantum and current efficiency of 6.78% and between the two light-emitting layers and using BCP at an applied voltage of 22V. The WOLED exhibits maximum 12cd/A respectively. By placing an undoped spacer CBP layer as hole blocking layer, the colour stabilization slightly changed when the driving voltage increased from 6 to 22 V. 相似文献
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细胞色素bc_1复合物的共振拉曼光谱 总被引:1,自引:1,他引:0
对不同氧化还原状态的细胞色素 bc_1复合物的共振拉曼光谱进行了分析比较。对部分拉曼信号的变化进行了指认。细胞色素 c_1的还原引起1640cm~(_1)和1560cm~(_1)及1454cm~(_1)的明显变小,细胞色素 b 的还原引起1544cm~(_1)的下降。这些信号可以标志复合物中不同色素的氧化还原状态,对拉曼方法用于研究呼吸链酶系有重要参考价值。 相似文献
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紫外差光谱测定Gd(Ⅲ), Yb(Ⅲ)与HBED配合物的条件稳定常数 总被引:1,自引:0,他引:1
在0.01 mol·L-1 N-2-羟乙基哌嗪-N'-2-乙磺酸(Hepes), pH 7.4, 室温条件下, 应用紫外差光谱滴定观察了Gd(Ⅲ), Yb(Ⅲ)与N, N'-二(2-羟苄基)乙二胺-N, N'-二乙酸(HBED)的结合. 结果表明 Gd(Ⅲ), Yb(Ⅲ)与HBED均形成1∶1的配合物, 其紫外差光谱均于237和291 nm处出现吸收峰, 在237 nm处配合物Gd-HBED与Yb-HBED的摩尔吸光系数分别为 ΔεGd=(22.52±0.20)×103 cm-1·mol-1·L, ΔεYb=(27.15±0.11)×103 cm-1·mol-1·L; 配合物Gd-HBED与Yb-HBED的条件稳定常数分别为 lgKGd-HBED=13.56±0.28, lgKYb-HBED=16.06±0.03, 符合线性自由能关系. 相似文献
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在还原气氛下采用高温固相法合成了BaMgAl10O17:Mn2 ,BaMgAl10O17:Eu2 ,BaMgAl10O17:Eu2 ,Mn2 粉末样品,测量并研究了它们的激发光谱和发射光谱性质.结果表明:BaMgAl10O17:Eu2 ,Mn2 中,Eu2 的发射光谱和Mn2 的吸收光谱之间的光谱交叠范围较大,两种离子之间发生了明显的交叉弛豫过程,即有较强的共振能量传递过程,导致在紫外光的激发下,样品BaMgAl10O17:Eu2 ,Mn2 发射光谱中以蓝光和绿光为主. 相似文献
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卟啉配合物-巯基棉体系分光光度法测定中药中铅、镉、铜 总被引:17,自引:0,他引:17
研究了卟啉与铅、镉、铜的反应及配合物的电子吸收光谱。结合巯基棉分离富集方法 ,将此金属卟啉配合物体系成功地应用于中药中微量铅、镉、铜的测定。方法简便 ,测定体系抗干扰的效果好 ,灵敏度高。实际样品测定的RSD在 3 3%~ 9 6 %之间。样品加标回收率在 90 %~ 1 0 3%之间。 相似文献
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溶解性有机物的荧光组份由于受到金属离子的影响其荧光强度受到变化,从而为溶解性有机物的定量分析带来挑战。利用三维荧光结合平行因子分析方法研究了Cu(Ⅱ), Fe(Ⅲ), Ni(Ⅱ), Sr(Ⅱ), Hg(Ⅱ), K(Ⅰ), Mg(Ⅱ) 和Mn(Ⅱ)八个金属离子对典型溶解性有机物荧光组分的荧光猝灭作用,五个水样来源各不相同。实验表明水样被平行因子成功分解为三个荧光组分(色氨酸、腐殖酸、富里酸),这三个荧光组份的荧光得分随着Fe(Ⅲ), Cu(Ⅱ), Hg (Ⅱ)和 Ni(Ⅱ)浓度的增加呈线性或指数下降。在这四种离子中,Fe(Ⅲ)和Cu(Ⅱ)对腐殖酸和富里酸的荧光猝灭作用明显大于Hg (Ⅱ)和 Ni(Ⅱ)。Sr(Ⅱ), K(Ⅰ), Mg(Ⅱ)和Mn(Ⅱ)基本没有影响。其中Fe(Ⅲ)对于三个荧光组分的荧光猝灭都有较好的分析。由于只考虑Fe(Ⅲ) 和Cu(Ⅱ)的影响,对于含有金属离子的饮用水的荧光强度的校正曲线也被建立。不同来源的饮用水中荧光组份的荧光得分的衰减规律也是不一样的,因此水样的来源也是测量时需要考虑的因素。实验证实了金属离子对溶解性有机物的荧光猝灭作用以及其他因素比如Fe(Ⅲ) 和Cu(Ⅱ)和溶解性有机物本身的多样性都是我们荧光测量典型荧光组份时需要考虑的。表明三维荧光结合平行因子分析方法是一个有效的准确测量溶解性有机物荧光组份的工具。 相似文献
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