Low-background EN-detector for the investigation of the neutron component of EASs

Thermal neutrons are detected using a scintillator compound based on ZnS(Ag) with B₂O₃ added to it. The pulse height generated by single charged particles in a scintillator of small thickness (50 mg/cm²) is not larger than that of a noise signal due to a low sensitivity to single charged particles. As a result, the detector satisfies the requirements of a low-background one in the context of cosmic-ray experiments. The detector is to be used for neutron detection in extensive air showers.     

渐变折射率介质在重叠复眼光学系统中的应用研究

在重叠复眼的生物结构中,晶锥部分的折射率随半径的增大逐渐变小,与渐变折射率(GRIN)介质十分相似。复眼具有体积小、重量轻、视场大、灵敏度高等优点。近年来,在智能武器、智能机器人视觉系统和微型飞行器等领域中,复眼光学系统得到了越来越多的应用。GRIN介质在重叠复眼光学系统中对会聚光线起到了关键的作用。从理论上对其进行了分析,得到了GRIN介质适用于重叠复眼光学系统中的条件;深入分析了GRIN介质出射光线聚焦点的位置关系;讨论了与重叠复眼灵敏度的关系。     

国产掺Nd3+透明薄片陶瓷的光学性能研究

研究了国产透明陶瓷Nd∶YAG和Nd∶YSAG的光学和激光性能.介绍了透明陶瓷Nd∶YAG和Nd∶YSAG的制作方法及其光谱性能,报道了相应的激光实验结果.对于Nd∶YAG薄片激光器,得到了中心波长1 064.2 nm,半高全宽为0.89 nm的激光输出,泵浦阈值功率0.267 W,最大激光输出功率0.319 W.对于Nd∶YSAG薄片激光器,由于荧光寿命比较长,可实现高掺杂,输出激光的中心波长为1 063.8 nm,半高全宽为1.6 nm,最大激光输出功率为0.356 W,斜率效率达23.2％,结果证明国产Nd∶YSAG陶瓷适用于短脉冲薄片激光器.     

Features of the formation of radiation spectra at (111) planar channeling of relativistic electrons in a Si crystal

The spectral intensity of (111) channeling radiation from electrons is numerically calculated at the energy varying from 100 to 900 MeV and different electron incidence angles relative to the (111) planes in thin Si crystals. The calculation results show that the channeling radiation’s spectra have a more complicated structure, and the total channeling radiation’s yield is several times larger than that at (100) or (110) channeling.     

大跨度钢桁桥模型的精细化损伤定位模拟和试验研究

在役大跨钢桁桥数日众多,其杆件往往较长,所以识别出损伤杆并找出局部损伤所处位置对安全评定和加固尤为重要。针对这一问题,参考我国在役钢桁梁桥,基于健康监测的试验目的和相似理论设计制作了贝雷梁式筒支钢桁桥Benchmark模型。根据其结构形式、具体尺寸,并经试验结果修正,建立了基准Matlab有限元模型。环境激励下,首先隔...     

Expected Spectra of Muon-Induced Cascades in IceCube

The neutrino telescope IceCube is capable to reconstruct the energy spectrum of muons in very high energy region by means of measurements of muon-induced cascades. To compare with experimental data, the expected spectra of cascades were theoretically estimated. Calculations were performed for two variants of muon spectrum on the ice surface: a simple power-law energy spectrum with a differential slope index −3.7, and a composite spectrum combined of two power spectra with differential indexes −3.7 and −2.7. The differential spectra of cascades for different zenith angles and integral cascade spectra calculated for two variants of muon spectra are discussed.     

Investigation of the Energy Loss of Muon Bundles in the Cherenkov Water Calorimeter

Investigations of the energy loss of muon bundles are being conducted at the Experimental complex NEVOD. Such investigations are directed to detailed study of “muon puzzle” (the excess of multi-muon events observed in several cosmic ray experiments at ultra-high energies). Results of measurements of the muon bundle energy deposit during a long period of observations in primary cosmic ray energy range 10–1000 PeV have been obtained and have been compared with simulations performed on the basis of the CORSIKA code.     

基于贵金属纳米簇的电化学发光传感器在生命分析中的应用

为了更好地研究贵金属纳米簇的合成机理、扩展贵金属纳米簇-电化学传感器的应用,阐述和比较了贵金属纳米簇的制备方法、电化学发光原理及特点,重点介绍了贵金属纳米簇-电化学传感器在生命分析领域的应用进展及本课题组相关研究,并展望了其发展和应用前景,以期为贵金属纳米簇电化学传感器在生命分析中的研究提供一定的参考。     

复杂目标光学散射截面数值仿真方法

研究复杂目标的几何建模、光学面元消隐和目标表面的光学散射特性.针对任意构型的目标,提出采用均匀光照明仿真图像进行光学散射截面（OCS）数值计算方法.通过自适应Z缓存方法,实现目标光学消隐面的计算,将这部分消隐面面积从目标OCS的数值积分中去除.研究近似镜面材料的空间模板褶皱表面的光学散射数值模拟方法,以及基于激光主动探测系统实验测量数据的目标OCS实验分析方法.根据某缩比例空间目标相对探测系统不同方位、俯仰角情况的OCS实验结果,校正OCS数值仿真参数.仿真结果与实验结果的图像比较和OCS曲线趋势大略一致,考虑到表面褶皱的随机性、姿态的测量误差和仿真模型有限的校准能力等因素,本文提出的数值仿真方法能够在一定程度上描述目标的OCS值.     

基于耦合开口方环共振空腔的可控法诺共振研究

基于表面等离子激元理论与金属-介质-金属波导结构提出一个由开口方环共振空腔、挡板及MIM波导组成的波导结构,并使用有限元方法系统地研究了该结构的透射特性.仿真计算结果表明:该结构可以产生法诺共振现象,其共振波长可以通过改变开口方环空腔的长度及开口大小进行调节,该结构敏感度可达1 600nm/RIU,品质因数为1.31×10~5.此外,通过调整方环共振空腔上开口的位置,在波导中产生了双重法诺共振现象,其敏感度可达1 700nm/RIU,品质因数为8.3×10~4.该结构有望在光学集成回路,尤其是纳米生物传感器方面得到比较广泛的应用.