圆柱盒型窗两端矩形波导位置偏差对传输性能的影响分析

采用三维电磁场模拟软件ISFEL3D计算分析了圆柱盒型窗在加工制作过程中,几种可能出现的两端矩形波导位置偏差对输出窗传输特性的影响,给出了驻波比随偏差量的数值关系曲线,并重点研究了哪些偏差有可能导致圆柱盒型窗中产生鬼模振荡。结果表明:两端矩形波导位置偏差对圆柱盒型窗驻波比的影响都不是很严重,但是若一端矩形波导位置沿垂直于宽边方向偏移或偏转一定角度时,有可能激发圆柱盒型窗中的鬼模振荡,从而对输出窗以至整个大功率微波系统造成严重危害。     

Eyringpy: A program for computing rate constants in the gas phase and in solution

Eyringpy is a modular program for calculating thermochemical properties and rate constants for reactions in the gas phase and in solution. The code is written in Python and it has a user-friendly interface and a simple input format. Unimolecular and bimolecular reactions with one and two products are supported. Thermochemical properties are estimated through canonical ensemble and rate constants are computed according to the transition state theory. One-dimensional Wigner and Eckart tunneling corrections are also available. Rate constants of bimolecular reactions involving the formation of pre-reactive complexes are also estimated. To compute rate constants in solution, Eyringpy uses the Collins–Kimball theory to include the diffusion-limit, the Marcus theory for electron transfer processes, and the molar fractions to account for the solvent pH effect.     

An efficient and highly diastereoselective synthesis of carbocyclic spiropyrazolones via one-pot sequential dual organo-silver catalyzed Michael-hydroalkylation reactions

An economical approach for the diastereoselective synthesis of highly functionalized carbocyclic spiropyrazolone derivatives having one quaternary and two tertiary stereocenters along with one exocyclic double bond exploiting dual organo-silver sequential catalysis has been developed. The unified method to both cyclohexyl and cyclopentyl spirocompounds involves the reaction of γ- and β-nitroalkynes with alkylidene pyrazolones catalyzed by Hünig’s base followed by carbophilic activation of the triple bond with a Ag(I) salt leading to cyclization via hydroalkylation.     

Synthesis,Crystal Structures,and Anti‐cervical Cancer Activity Evaluation of Three Trinuclear Transition Metal(II) Complexes with N,O‐Donor Schiff Base Ligand

A new bi‐nucleating Schiff base ligand, 2‐(((3‐(dimethylamino)propyl)imino)methyl)‐6‐methoxyphenol (HL₁) was prepared by a one‐pot condensation reaction, which was further used in the construction of three trinuclear Schiff base transition metal(II) complexes [Cu₃(L1)₂(OH)₂(H₂O)₂](NO₃)₂ ( 1 ), [Co₃(L1)₂(OH)₂(H₂O)₂](NO₃)₂ ( 2 ), and [Cu₃(L1)₂(N₃)₄] ( 3 ). Furthermore, a green hand grinding technique was implemented to reduce the particle size of the coordination complexes to generate the nanoscale compounds. The SEM studies reveal the formation of square and spherical particles for nano 1 and 2 , and nanorod for nano 3 . In addition, the anti‐proliferation activity of nano 1 – 3 was detected on the human cervical cancer Hela cells with CCK‐8 assay. The cell viability curves and IC₅₀ values indicated that only nano 1 has anti‐proliferation activity on Hela cells. To further investigate the mechanism of nano 1 induced Hela cell death, the Annexin V‐FITC/PI double staining assay, western blot assay, and ROS level detection was conducted.     

Schiff base/ester liquid crystals with different lateral substituents: mesophase behaviour and DFT calculations

Four new groups of 4-((2?-substitutedphenylimino)methyl)phenyl-4”-alkoxy benzoates, In_a-d, of Schiff base ester liquid crystals, were prepared and investigated for their mesophase formation and stability. Each group constitutes four homologous series that differ from each other by the lateral attached polar group X in the ortho position for the imine mesogen at terminal benzene ring that alternatively changed from F, Br, NO2 and lateral benzene ring. Within each homologous series, the number (n) of carbons in the alkoxy chain varies between 6, 8, 10 and 12. Molecular structures of the prepared compounds were confirmed via elemental analysis, FT-IR, and ¹H NMR spectroscopy. Mesomorphic properties were investigated by differential scanning calorimetry (DSC) and the phase identified by polarised light microscopy (PLM). A comparative study was made between the investigated compounds and their previously prepared laterally neat, 4-((4?-phenylimino)methyl)phenyl-4”-alkoxy benzoates (IIn); the result revealed that all lateral substituents not only decrease the melting temperature but also the mesophase stability and shown only nematic phase. Density functional theory (DFT) calculations for new lateral derivatives were discussed.     

新型轻质阻尼基座设计与隔振性能研究

为了减少船体振动与辐射噪声,采用声子玻璃和弧形衔接结构设计了一种新型轻质阻尼基座。然后用加速度振级落差表征其隔振性能,开展了水泵电机激励下的基座隔振性能试验研究, 结果表明阻尼基座在20$\sim$10 000 Hz的频率范围具有显著的隔振效果,相较于同尺寸钢制基座,其振动落差总级可达12.93dB。研究结果充分验证了本文设计的轻质阻尼基座具备高强度、高阻尼、宽频隔振的特点,在舰船机械设备等减振降噪领域具有广泛的潜在应用价值。     

蜗窗激励评价的有限元计算模型研究

蜗窗驱动是实现中耳听力装置与耳蜗耦合的新途径. 利用外耳道、中耳和耳蜗集成有限元模型, 分别模拟外耳道声激励经听骨链、前庭窗传入内耳的正向传递过程和蜗窗机械激励在耳中逆向传递过程, 计算获得中耳和耳蜗的传递函数. 比较蜗窗激励和外耳道激励下耳蜗基底膜的振动, 提出了以基底膜最佳反应部位位移相等为准则的蜗窗等效激励力计算方法. 理论计算获得的蜗窗等效激励力与相关文献根据实验数据预测结果一致. 计算结果还表明耳蜗窗正、逆向激励时, 基底膜上最佳反应部位无变化, 但在蜗窗逆向激励耳蜗时, 低频下驱动基底膜运动的效率比高频时低. 所获得的理论结果可为蜗窗驱动的听力装置设计和现有装置的应用提供参考.     

An inviscid model for the base pressure of transonic turbine cascade

An inviscid base pressure model for transonic turbine blade has been presented. It has been shown that for a given back pressure the base pressure at the trailing edge, and the profile loss of a turbine blade are fixed according to the model and the base pressure can be calculated with the help of an inviscid numerical scheme. A parameteric study on the model shows that a blade profile with positive curvature downstream of the throat is advantageous for generating less loss, whilst the worst situation is when the exit flow reaches the sonic condition.     

用曲线大窗口平滑散斑条纹图的方法研究

提出一种计算条纹方向的简单算法,以及通过条纹方向图获得沿条纹方向的曲线窗口并对散斑条纹图进行曲线大窗口滤波的方法．实验表明此方法较好地消除了散斑条纹图的噪声,同时尽量减小了对条纹结构的损害．为从单幅散斑条纹图中应用条纹中心线法或全灰度法进一步提取相位场的后处理,奠定了良好的基础．