Analysis of Detectors and Transmission Curve Correction of Mobile Rayleigh Doppler Wind Lidar

A mobile molecular Doppler wind lidar （DWL） based on double-edge technique is presented for wind measurement at altitudes from 10 km to 40 km. A triple Fabry-Perot etalon is employed as a frequency discriminator to determine the Doppler shift proportional to the wind velocity. The lidar operates at 355 nm with a 45-cm aperture telescope and a matching azimuth-over-elevation scanner that can provide full hemispherical pointing. In order to guarantee the wind accuracy, different forms of calibration function of detectors in different count rates response range would be especially valuable. The accuracy of wind velocity iteration is improved greatly because of application of the calibration function of linearity at the ultra low light intensity especially at altitudes from 10 km to 40 km. The calibration functions of nonlinearity make the transmission of edge channel 1 and edge channel 2 increase 38.9% and 27.7% at about 1 M count rates, respectively. The dynamic range of wind field measurement may also be extended because of consideration of the response function of detectors in their all possible operating range.     

高发光效率CdTe@SiO2量子点的制备

SiO2包覆CdTe量子点过程中通常导致荧光效率大幅降低,严重影响后续分析应用的灵敏度.为制备高发光效率的CdTe@SiO2量子点,基于吐温80/环已烷/1-已醇/CdTe量子点反相微乳液体系,考察了TEOS和氨水的用量、反应时间及助表面活性剂种类对制备CdTe@SiO2的影响.利用透射电子显微镜、分子荧光光谱仪以及紫外可见分光光谱仪对制备的CdTe@SiO2形貌和性能进行了表征.结果 表明,CdTe@SiO2的最佳制备条件是TEOS和氨水的用量均为120 μL,反应时间为24 h,助表面活性剂为1-己醇.CdTe@SiO2量子产率为27.9;,相对包覆前,量子产率保持率为84.5;.     

脉冲声的功率

本文提出了一种以声压包络为基础的脉冲声功率的计值方案,并认为由此而得的值可定义为脉冲声功率,从而可与现有的术语组成一套较完整的超声功率方面的术语系统。     

三氟氯氰菊酯农药中微量杂质的液相色谱－质谱法鉴定

用高效液相色谱－质谱联用技术研究了三氟氯氰菊酯农药的杂质及含量,并用源内碰撞诱导解离（CID）技术鉴别了所存在的微量杂质。方法实用性强,色谱分离效果好,可用于该农药各成分的定性、定量分析。     

SPECIFYING NODES AT MULTIPLE LOCATIONS FOR ANY NORMAL MODE OF A LINEAR ELASTIC STRUCTURE

Spring-mass oscillators have long been used as vibration absorbers to quench excess vibration in structural systems. In this paper, sprung masses are used as a passive means of inducing multiple nodes for any normal mode of an arbitrarily supported, linear elastic structure. When the parameters of the elastically mounted masses are properly chosen, their attachment locations can be made to coincide exactly with the nodes of the structure, thereby allowing nodes to be imposed at multiple locations anywhere along the combined assembly. Moreover, when the desired node locations are closely spaced, it is possible to specify a region of nearly zero amplitudes for a particular normal mode. A procedure to guide the proper selection of the spring-mass parameters in order to induce multiple nodes is outlined in detail, and numerical experiments are performed to verify the utility of the proposed scheme of imposing nodes at multiple locations.     

10kW横流CO2激光器的增益特性

本文描述了一台10kW横流CO_2激光器在脉冲予电离下的增益特性及关于增益分布和脉冲予电离的理论分析.     

荧光共振能量转移增敏法测定锌

以巯基乙酸为稳定剂合成了CdTe量子点,并利用其与牛血清白蛋白(BSA)组成了荧光共振能量转移体系,考察BSA(供体)和CdTe量子点(受体)之间的荧光共振能量转移的最佳条件,建立了荧光共振能量转移增敏法测定Zn2+的新方法.在pH 7.4的Tris-HCl缓冲溶液中,Zn2+能对能量转移体系中CdTe量子点增敏从而测定锌的含量.Zn2+浓度在0.49-4.88μg/mL浓度范围内与CdTe量子点荧光强度呈现良好线性关系(r=0.9996),检出限为0.13μg/mL,RSD为3.2％,平均回收率为99.5％(n=5).方法适用于果汁饮料中微量锌的测定.     

谷胱甘肽稳定的CdTe量子点荧光猝灭法测定痕量过氧化氢

以谷胱甘肽稳定的CdTe量子点作为荧光探针,基于荧光猝灭法对过氧化氢进行了定量检测,考察了缓冲溶液体系、量子点浓度、反应时间等多种因素的影响。实验结果表明,在pH=7.2的Na2HPO4-NaH2PO4缓冲液中,反应时间为15min,过氧化氢浓度为1.0×10-6～3.0×10-5 mol/L范围时,其线性回归方程为△F=9.78+7.56c(10-6 mol/L),线性相关系数和检测限分别为0.9992和1.27×10-8 mol/L。谷胱甘肽稳定的CdTe量子点荧光猝灭法已用于水样的测定,回收率在96%～103%之间,相对标准偏差RSD不大于3.3%,结果令人满意。     

CdTe量子点与罗丹明6G间的荧光共振能量转移机理研究

本文在合成水溶性巯基乙酸修饰的CdTe量子点的基础上,研究了CdTe量子点与罗丹明6G之间的荧光共振能量转移.实验结果表明:构建的CdTe量子点(供体)-罗丹明6G(受体)荧光共振能量转移体系在磷酸盐缓冲溶液中有较好的转移效果.当磷酸缓冲溶液pH值为7.4,NaCl浓度为1.0 mol/L时,构建的CdTe量子点-罗丹...     

PEMFC电极中表面扩散现象的初步研究

制作双催化层结构的PEMFC电极.该双催化层由含有Nafion的内催化层、无Nafion的外催化层组成.循环伏安测试表明,未与Nafion直接接触的外催化层Pt/C催化剂也参与发生在"Pt/Nafion"界面氢原子的吸脱附反应和Pt表面含氧粒子的电化学氧化还原.当电势扫描速率较低时,未与Nafion直接接触的外层Pt/C催化剂,其对氢脱附电流的贡献和直接与Nafion接触的内催化层的Pt/C催化剂大致相当.以双催化层电极作PEMFC阴极,单电池(PEMFC)极化曲线测试表明,其阴极外催化层能明显地提高该单电池在活化极化区的输出性能.进一步证明了PEMFC阴极外催化层不与Nafion直接接触的Pt/C催化剂可通过其表面吸附含氧粒子的表面扩散参与发生在"Pt/Nafion"界面氧的电化学还原反应.上述实验为设计PEMFC电极提供了一定的新思路.