Bent函数的对偶性

研究了Bent函数的对偶性,通过利用对偶函数的定义得到了两个Bent函数导数的Walsh谱与它们对偶函数导数的Walsh谱是相关的;同时,得到两个Bent函数之和与它们的对偶函数之和有相同的汉明重量.     

二萘并噻咯的合成及性能

Siloles constitute an important emerging class of photoluminescent materials. A series of compounds consisting of silole cores and fused naphthalene were synthesized and characterized:6, 6-dimethyl-1, 2, 3, 4, 8, 9, 10, 11-octapropyl-6H-dinaphtho[2, 3-b:2', 3'-d]silole, 1, 2, 3, 4, 8, 9, 10, 11-octabutyl-6, 6-dimethyl-6H-dinaphtho[2, 3-b:2', 3'-d]silole, 6, 6-diphenyl-1, 2, 3, 4, 8, 9, 10, 11-octapropyl-6H-dinaphtho[2, 3-b:2', 3'-d]silole, and 1, 2, 3, 4, 8, 9, 10, 11-octabutyl-6, 6-diphenyl-6H-dinaphtho[2, 3-b:2', 3'-d]silole. These dinaphthalene-fused siloles were synthesized from diiodonaphthalene, which was prepared by a direct coupling method. Subsequent reaction in the presence of n-butyllithium yielded 3, 3'-diiodo-2, 2'-binaphthalene. Direct substitution of two chloride ions from Ph₂SiCl₂ or Me₂SiCl₂ with 3, 3'-dilithio-2, 2'-binaphthalene then yielded the multi-substituted silole. Nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry were used to characterize the structures of the siloles. Their optical and electronic properties were investigated using ultraviolet-visible absorption spectroscopy, photoluminescence spectroscopy, cyclic voltammetry, and density functional theory calculations. The dinaphthalene-fused siloles exhibited similar absorption and emission peaks. Their deep highest occupied molecular orbital level at approximately -5.5 eV indicated that they were chemically stable. Differential scanning calorimetry and thermogravimetric analysis indicated that the siloles were stable up to 309℃. A multilayer electroluminescent device was fabricated using 1, 2, 3, 4, 8, 9, 10, 11-octabutyl-6, 6-dimethyl-6H-dinaphtho[2, 3-b:2', 3'-d]silole as a light-emitting layer. The resulting device produced bright blue emission, indicating that these siloles may be suitable materials in organic light-emitting devices.     

FTIR Studies on NO Adsorption on [Co+Mg(Sr)]/ZSM-5

IntroductionThe FTIR spectroscopy of NO adsorption on[Co +Mg(Sr) ]/ZSM- 5 has not been fullyelucidated yet.Previous researchers working onNO adsorption over Co/ZSM- 5 stated that thebands at 1 81 0 and 1 890 cm-1are due to dinitrosylspecies adsorbed on Co2 +[1] ,while the band at193 5 cm-1is attributable to mononitrosyl species.Aband near1 85 8cm-1(w) may be attributable tothe species of Co3O4 —NO[2 ] .Further,Zhu etal.[2 ]reported the bands at1 81 3 ,1 896 and1 93 9cm-1assigned to …     

弗兰克-赫兹实验中两种测量模式及数据处理探讨

探究了自动测量和手动测量两种模式对弗兰克-赫兹实验结果的影响,在最佳参数下给出的F-H曲线都比较光滑。为了得到氩原子第一激发电位,我们分别利用Origin 8软件和最小二乘法理论公式对峰位序号和对应扫描加速电压进行线性拟合,结果发现和其他文献及理论结果符合较好。     

三区分划射线追踪法研究及其应用

根据高频(HF)信道的特点和要求，对三区分划射线追踪法的精度进行了深入分析，结果表明三区分划射线追踪法可用于HF信道的模拟研究．提出并实现了利用三区分划射线追踪法替代Vogler法信道模拟中的射线参数理论求解部分，解决了Vogler方法在HF信道模拟应用中存在的适用范围窄等问题．通过与Vogler模拟方法的比较，散射函数的形状完全一样，而且可以得到利用Vogler方法无法确定的射线的入射角等有用信息，从而验证了本文方法的正确性和优越性．     

EFFECT OF HIGH-ANGLE DIFFRACTION DATA ON RIETVELD STRUCTURE REFINEMENT

By utilizing the powder X-ray step-scanning diffraction data of PbSO₄, we have studied the effect of the diffraction data (with different high-angle upper-limit: 2θ_m= 160,140,120,100,80, 70 and 60°) on the precision of the Rietveld refined lattice constants, structure parameters, and agreement indices. Tbese refined results are compared with those obtained from the single crystal data. It is revealed that the deviations of the refined lattice constants, atomic positions and isotropic temperature factors decrease, and agreement indices become smaller With the increase of 2θ_m. But when 2θ_m> 120°, the deviations and agreement indices decrease very slowly. Therefore, in general cases, 2θ_m should be taken to be 120°or larger in order to get satisfactory refined results in the Rietveld crystal structure refinement.     

以牛血清白蛋白为荧光探针的格列吡嗪含量测定方法

在pH=7.40的Tris-HCl缓冲溶液中,牛血清白蛋白(BSA)与格列吡嗪(Glipizide)的相互作用会使BSA荧光有规律地发生猝灭,据此建立了以BSA为探针的Glipizide含量测定方法。Glipizide浓度在0.25～20μmol/L范围内与荧光强度呈现良好的线性关系,方法的检出限为0.071μmol/L。对于片剂中Glipizide含量的测定,平行6次测定的相对标准偏差为1.29%～2.80%,回收率为86.79%～96.43%。     

Room-Temperature Continuous-Wave Operation of InGaN-Based Blue-Violet Laser Diodes with a Lifetime of 15.6 Hours

We report our recent progress of investigations on InGaN-based blue-violet laser diodes （LDs）. The roomtemperature （RT） cw operation lifetime of LDs has extended to longer than 15.6 h. The LD structure was grown on a c-plane free-standing （FS） GaN substrate by metal organic chemical vapor deposition （MOCVD）. The typical threshold current and voltage of LD under RT cw operation are 78 mA and 6.8 V, respectively. The experimental analysis of degradation of LD performances suggests that after aging treatment, the increase of series resistance and threshold current can be mainly attributed to the deterioration of p-type ohmic contact and the decrease of internal quantum efticiency of multiple quantum well （MQW）, respectively.     

壁温周期变化引起的一维热声波的数值模拟

本文采用可压缩流动的SIMPLE算法对壁温周期变化引起的气体中的一维热声波的产生和传播进行了数值模拟,分析了其中的流动和换热规律.计算结果表明,壁面温度周期变化可以产生大振幅的热声波,当其达到准平衡状态时温度产生稳态的超温现象,超温幅度的大小和极值的位置随着加热温度的振幅和频率变化而不同.超温现象导致冷壁面的温度梯度增大,强化了介质与冷壁面间的换热.     

Synthesis of Biphasic Defective TiO2-x/Reduced Graphene Oxide Nanocomposites with Highly Enhanced Photocatalytic Activity

Biphasic defective TiO_2-x/reduced graphene oxide(RGO) nanocomposites were synthesized by simple hydrothermal reactions. Compared with TiO_2-x and commercial P25, TiO_2-x/RGO shows much better photocatalytic activity and excellent stability in pollutants degradation, which could be ascribed to Ti³⁺ centers complexed with RGO and the synergetic effect between the two phases. The study reveals a new route for the synthesis of mixed-phase defective TiO_2-x/carbon material nanocomposites for photocatalytic applications.