Field Patterns in Double Circular-Groove Guide by Finite Element Method

The electromagnetic power coupling in symmetrical and asymmetrical double circular-groove guides have been analyzed by finite element method (FEM) in this paper. The electrical field patterns of the dominant mode and the first higher-order TE mode have been presented. The electromagnetic field of the dominant mode distributes with a concentration in the two grooves and the region between grooves as well for symmetrical double circular-groove guide, while it distributes with a concentration in the groove with larger radius for the asymmetrical double circular-groove guide. The electrical field patterns of the first higher-order TE mode in symmetrical and asymmetrical double circular-groove guide are also presented. The figures in this paper have important values in design of circular-groove guide power coupler for millimeter wave applications.     

Positive solutions of nonlinear three-point boundary-value problems

Let a∈C[0,1], b∈C([0,1],(−∞,0]). Let φ₁(t) be the unique solution of the linear boundary value problem

u″(t)+a(t)u′(t)+b(t)u(t)=0,t∈(0,1),u(0)=0,u(1)=1.     

On the multiplicity of Laplacian eigenvalues for unicyclic graphs

Let G be a connected graph of order n and U a unicyclic graph with the same order. We firstly give a sharp bound for m_G(μ), the multiplicity of a Laplacian eigenvalue μ of G. As a straightforward result, m_U(1) ? n ? 2. We then provide two graph operations (i.e., grafting and shifting) on graph G for which the value of m_G(1) is nondecreasing. As applications, we get the distribution of m_U (1) for unicyclic graphs on n vertices. Moreover, for the two largest possible values of m_U(1) ∈ {n ? 5, n ? 3}, the corresponding graphs U are completely determined.

     

Xe~(53+)离子与Xe原子碰撞过程中的辐射电子俘获和辐射退激发光谱的理论研究

基于多组态Dirac-Fock方法和密度矩阵理论,系统地研究了在197 Me V/u的碰撞能量下,Xe~(53+)离子与Xe原子的辐射电子俘获过程(REC)以及电子被俘获到激发态后辐射退激发产生的特征谱线.计算了炮弹Xe~(53+)离子俘获电子到不同壳层np_(1/2,3/2)(n=2—5)的总截面与相应的REC光子能量和角分布,以及由激发组态1snp_(1/2,3/2)(n=2—5)J_f=1向基态1s~2Jd=0辐射退激发的跃迁能量、跃迁概率和特征光子的角分布和线性极化度.计算结果表明,辐射光子具有显著的角各向异性特征.此外,1snp_(3/2)J_f=1→1s~2J_d=0退激发特征光子也显示出很强的线性极化和角各向异性特征,而1snp_(1/2)J_f=1→1s~2J_d=0退激发特征光子的线性极化度趋于零并且角分布也趋于各向同性.     

供应中断下最优分配和应急采购策略的比较

最优分配采购策略和应急采购策略被广泛应用于供应中断风险管理中,基于最优分配采购策略和应急采购策略,研究了由两个制造商与两个零售商组成的两级供应链在供应中断下的订购和生产决策问题,给出了最优订购和最优生产策略.通过数值例子就可靠性如何影响制造商的最优价格和利润进行了比较.结果表明:随着可靠性的增加,两个制造商的最优价格呈递减态势,且制造商A的递减幅度小于制造商B的递减幅度;当可靠性低于0.3时,制造商A的最优价格低于制造商B的最优价格,当可靠性高于0.3时,制造商A的最优价格高于制造商B的最优价格.随着可靠性的增加,制造商A的利润呈递减态势,制造商B的利润呈递增态势;当可靠性低于0.8时,制造商A的利润高于制造商B的利润,当可靠性低高于0.8时,制造商A利润低于制造商B的利润.     

The Organosilicon thin Film Deposited Using an Atmospheric Pressure Dual‐Frequency 50 kHz/33 MHz Frequency MicroPlasma Jet

In this paper, an atmospheric pressure dual‐frequency (50 kHz/33 MHz) micro‐plasma jet was used to deposit organosilicon film. The discharge generated in atmospheric environment. Plasma composition was characterized by optical emission spectroscopy. With introduction of tetraethyl orthosilicate, we observed various spectra, for example Si(251.6 nm), OH(308.9 nm), C(247.8 nm), O(777.5 nm). Abundant reactive radical species which are benefit to film deposition were generated in plasma. The deposited film was characterized by scanning electron microscopy, X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The film is mostly composed of Si and O. The film has Si‐O‐Si backbone with a small number of organic component (‐CHx). (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

微波辐射下2-芳氧甲基苯并咪唑类化合物的合成

以多聚磷酸和4 mol/L盐酸(PPA-HCl)作催化剂, 在微波辐射条件下合成了13种2-芳氧甲基苯并咪唑类化合物, 其中6种尚未见报道. 其结构经元素分析, IR, ¹H NMR, ¹³C NMR及MS确证. 与经典方法相比, 微波条件下的反应具有时间短、收率高等优点. 反应物邻苯二胺与芳氧基乙酸的物质的量比为1∶1.1, 催化剂PPA与HCl的最佳比例为1∶1(体积比), 最适宜的微波辐射功率为650～850 W, 反应时间为10～15 min.     

Clean and selective Baeyer-Villiger oxidation of ketones with hydrogen peroxide catalyzed by Sn-palygorskite

An environmentally benign and selective Baeyer-Villiger oxidation system is introduced. Palygorskite-supported Sn complexes were prepared by a simple procedure. Cyclic ketones and acyclic ketones were oxidized by hydrogen peroxide in a reaction catalyzed by palygorskite-supported Sn complexes, affording corresponding lactones or esters with selectivity for the product of 90-99%. The influence of the solvents, reaction temperature, the amount of catalyst used and the reaction time on the catalytic activity and product selectivity were investigated in detail. The catalyst is cheap, easy to be prepared in large scale and can be recycled.     

N-乙氧羰基-N'-取代芳基硫脲晶体中的弱相互作用及超分子结构研究

合成了3种N-乙氧羰基-N'-取代芳基硫脲并确定了其晶体结构, 晶体结构表明, 在这些化合物中存在分子内及分子间的氢键, 分子间的氢键将化合物1和2组装成了一维链状的超分子结构, 由于空间因素, 化合物3没有形成类似于1, 2中的氢键组装成的链状超分子结构, 而是形成了氢键链接的二聚体. 同时在化合物1, 3中还存在分子间的芳环间的π-π相互作用. 在化合物1的晶体中, 这种π-π相互作用使相邻的超分子链之间相互关联. 化合物3的晶体中, 相邻的二聚体间又通过π-π相互作用连接成了无限延伸的一维链状结构.     

气体喷泉实验装置的改进及应用

采用丙酮将有机玻璃黏合成1个三室气体双喷泉实验装置,该装置将气体收集及喷泉实验一体化,使实验过程更加简单,便于操作,实验现象更加明显,趣味性增强。此外,该装置功能更加多样,还可用于气体双性质验证。