3-辛基噻吩的质谱分析

共轭聚合物通常具有一些独特的物理性质,如高的电导率、电致发光、电致变色、非线性光学性质等。这类共轭聚合物包括聚苯胺、聚噻吩、聚吡咯、聚对苯乙炔、聚对苯等。自英国剑桥大学的Burrougs等人[1]采用聚对苯乙炔成功地制备了第一个聚合物电致发光器件以来,对聚合物电致发光     

Y2O3:Eu纳米晶的硝基取代苯甲酸配合物固相热解制备和性能

以苯甲酸、邻硝基苯甲酸、间硝基苯甲酸、对硝基苯甲酸、3，5－二硝基苯甲酸等为配体制备了Y^3 、Eu^3 二元配合物，配合物中Y^3 与Eu^3 的摩尔比为9：1，利用这些配合物的爆炸式热分解特性通过固相热解反应制备了一系列Y2O3：Eu纳米晶。透射电镜观察，可以看出所得纳米晶呈球形，粒度介于40－60nm，X射线衍射分析表明实验所得纳米晶属立方晶系，粒径与电镜观察所得结果基本一致；Eu^3 的引入并不影响Y2O3的晶相组成；配体类型对纳米晶的结构没有显著影响，不过相对于硝基取代苯甲酸配合物，苯甲酸配合物热解所得Y2O3：Eu纳米晶团聚严重；退火温度显著影响纳米晶粒度，退火温度高，纳米晶粒度大，反之亦然。荧光光谱测定表明所有Y2O3：Eu纳米晶具有相似的发光行为，其中以苯甲酸配合物分解所得Y2O3：Eu纳米晶发光性能最为优越。     

梵塔问题的两个定理

本文首次证明了梵塔问题的两个定理,建立了一种梵塔问题新算法．     

氘离子束轰击石墨引起化学腐蚀的实验进展

在ＳＭＦ－８００ 石墨第一壁化学腐蚀温度特性的实验研究基础上,进一步测试了Ｇ３ 石墨、ＳＭＦ－８００ 高纯石墨和硼化石墨,以及ＳｉＣ涂层等在１．３μＡ／３ｋｅＶ 氘离子束轰击下化学腐蚀的温度特性。从中优选出Ｃ２Ｂ１０Ｈ１２ 氦辉光放电法制取的ＳＭＦ－８００ 石墨硼化层,它具有最佳的抗化学腐蚀性能。其ＣＤ４ 产额较ＳＭＦ－８００ 高纯石墨的降低一个数量级以上,ＣＤ４ 产额峰值温度下移至６５０Ｋ附近。用小角度转动样品法,初步观察了氘离子束轰击下石墨释放ＣＤ４ 的角分布特性,为托卡马克先进偏滤器实验中确立ＣＤ４ 辐射区的定位及其控制等可行性进行了探索     

Effect of crystallographic orientations on transport properties of methylthiol-terminated permethyloligosilane molecular junction

The understanding of the influence of electrode characteristics on charge transport is essential in the field of molecular electronics. In this work, we investigate the electronic transport properties of molecular junctions comprising methylthiol-terminated permethyloligosilanes and face-centered crystal Au/Ag electrodes with crystallographic orientations of (111) and (100), based on the ab initio quantum transport simulations. The calculations reveal that the molecular junction conductance is dominated by the electronic coupling between two interfacial metal-S bonding states, which can be tuned by varying the molecular length, metal material of the electrodes, and crystallographic orientation. As the permethyloligosilane backbone elongates, although the σ conjugation increases, the decreasing of coupling induced by the increasing number of central Si atoms reduces the junction conductance. The molecular junction conductance of methylthiol-terminated permethyloligosilanes with Au electrodes is higher than that with Ag electrodes with a crystallographic orientation of (111). However, the conductance trend is reversed when the electrode crystallographic orientation varies from (111) to (100), which can be ascribed to the reversal of interfacial coupling between two metal-S interfacial states. These findings are conducive to elucidating the mechanism of molecular junctions and improving the transport properties of molecular devices by adjusting the electrode characteristics.     

方波驱动法测定Alq3的电子迁移率

在非正弦波(方波)的驱动下,观察到了OLED中Alq₃的电致发光现象。在高段方波驱动下,Alq₃中的电子向阳极移动;在低段方波驱动下,Alq₃中的电子向阴极移动。当方波的周期是电子穿过Alq₃中所用时间的2倍时,Alq₃中的电致发光现象完全消失。由此,可以计算出Alq₃中的电子迁移率,得到的结果和文献的报道值相吻合。对Alq₃中电子迁移率和厚度的关系进行了研究,从而提出了一种简单易行的计算有机材料的电子迁移率的方法。     

光声光谱法测定枪药表面高分子钝感剂的浓度分布

采用步进扫描傅里叶变换红外光声光谱法测定小尺寸钝感枪药表面高分子钝感剂浓度分布趋势,证实了该技术在含能材料近表面分析和研究中的实用价值。     

激光告警接收机灵敏度和信噪比分析及实验验证

为了对抗现代战争中日趋严重的激光威胁,激光告警技术已成为亟需研究的课题之一。灵敏度和信噪比是激光告警系统重要的性能指标,它直接影响告警系统整体的探测性能。文中根据信号统计检测理论,提出了一种计算相干探测光谱识别型激光告警接收机灵敏度和信噪比的方法。首先,分析了激光信号和接收机噪声的概率分布。然后,基于阈值探测理论和奈曼—皮尔逊准则,通过引入探测概率因子和虚警概率因子,建立了信号电流方程,进而得到了灵敏度和信噪比的计算表达式。最后,利用该方法对自行研制的光栅衍射激光告警接收机的探测灵敏度和信噪比进行了理论计算和相关的实验验证, 结果表明：由该方法计算的灵敏度和信噪比与实验结果基本相符。     

溅射时间对室温沉积ITO薄膜光电性能的影响

利用对靶磁控溅射方法在尺寸为6 cm×6 cm有机玻璃衬底上室温沉积ITO透明导电氧化物薄膜,重点研究了沉积时间对于ITO薄膜导电性、可见光透光性以及红外发射特性的影响.结果发现随溅射时间延长,薄膜厚度呈线性增加;XRD分析显示薄膜逐渐由非晶结构转变为(400)与(440)取向的多晶结构;薄膜导电性能提高,电阻率整体迅速下降,在溅射时间为60 min时达到最小为2.1×10-4Ω·cm,载流子浓度达到最高值为1.2×1021 cm-3,同时薄膜红外发射率最低可达0.17;薄膜可见光透光率逐渐下降,并且在紫外光区域出现一定红移.     

1,4-二氧六环的真空紫外同步辐射光解离电离研究

The photoionization and photodissociation of 1,4-dioxane have been investigated with a reflectron time-of-flight photoionization mass spectrometry and a tunable vacuum ultraviolet synchrotron radiation in the energy region of 8.0-15.5 eV. Parent ion and fragment ions at m/z 88, 87, 58, 57, 45, 44, 43, 41, 31, 30, 29, 28 and 15 are detected under supersonic conditions. The ionization energy of DX as well as the appearance energies of its fragment ions C₄H₇O₂⁺, C₃H₆O⁺, C₃H₅O⁺, C₂H₅O⁺, C₂H₄O⁺, C₂H₃O⁺, C₃H₅⁺, CH₃O⁺, C₂H₆⁺, C₂H₅⁺/CHO⁺, C₂H₄⁺ and CH₃⁺ was determined from their photoionization efficiency curves. The optimized structures for the neutrals, cations, transition states and intermediates related to photodissociation of DX are characterized at the B3LYP/6-31+G(d,p) level and their energies are obtained by G3B3 method. Possible dissociative channels of the DX are proposed based on comparison of experimental AE values and theoretical predicted ones. Intramolecular hydrogen migrations are found to be the dominant processes in most of the fragmentation pathways of 1,4-dioxane.