95 GHz准光模式转换器实验研究

介绍了采用95 GHz准光模式转换器将TE62模式转换为高斯波束的实验测试结果。准光模式转换器由螺旋切口的Vlasov辐射器、一个准抛物柱面反射镜和两个相位修正镜组成。将半径5.62 mm圆波导内的TE62模式转换为束腰直径22.4 mm的高斯波束。实验采用毫米波天线近场扫描测试系统测试,实验结果表明标量转换效率大于97%,矢量转换效率大于88%     

BiOCl nanowire with hierarchical structure and its Raman features

BiOCl is a promising V-VI-VII-compound semiconductor with excellent optical and electrical properties, and has great potential applications in photo-catalysis, photoelectric, etc. We successfully synthesize BiOCl nanowire with a hierarchical structure by combining wet etch (top-down) with liquid phase crystal growth (bottom-up) process, opening a novel method to construct ordered bismuth-based nanostructures. The morphology and lattice structures of Bi nanowires, β-Bi₂O₃ nanowires and BiOCl nanowires with the hierarchical structure are investigated by scanning electron microscope (SEM) and transition electron microscope (TEM). The formation mechanism of such ordered BiOCl hierarchical structure is considered to mainly originate from the highly preferred growth, which is governed by the lattice match between (1 1 0) facet of BiOCl and (2 2 0) or (0 0 2) facet of β-Bi₂O₃. A schematic model is also illustrated to depict the formation process of the ordered BiOCl hierarchical structure. In addition, Raman properties of the BiOCl nanowire with the hierarchical structure are investigated deeply.     

ICP-MS同时测定饮用水中的19种元素

以Li、Sc、Ge、In、Bi作内标,采用电感耦合等离子体-质谱法(ICP-MS)同时测定饮用水中Fe、Hg、As、Pb等19种元素.方法的线性范围宽,灵敏度高,线性相关系数均不低于0.9990,相对标准偏差均在7.1％之内,各元素的加标回收率均92.5％-108.0％.方法准确、快速、便捷,能为绵阳灾后重建水质安全提供有力保障.     

高斯型耦合多光子Tavis-Cummings模型中场与原子的纠缠特性

利用全量子理论,研究了多光子跃迁过程高斯型耦合Tavis-Cummings模型中场与原子的纠缠特性。讨论了多光子原子运动速度、光场初态的平均光子数及跃迁光子数对场与原子之间纠缠特性的影响。结果表明:原子运动速度的变化改变了场熵演化曲线的振荡时域;光场初态影响场熵演化曲线的周期性;跃迁光子数的增加使场熵演化曲线的振荡频率和场与原子之间的平均纠缠度变大。     

Development of Lattice Boltzmann Flux Solver for Simulation of Incompressible Flows

A lattice Boltzmann flux solver (LBFS) is presented in this work for simulation of incompressible viscous and inviscid flows. The new solver is based on Chapman-Enskog expansion analysis, which is the bridge to link Navier-Stokes (N-S) equations and lattice Boltzmann equation (LBE). The macroscopic differential equations are discretized by the finite volume method, where the flux at the cell interface is evaluated by local reconstruction of lattice Boltzmann solution from macroscopic flow variables at cell centers. The new solver removes the drawbacks of conventional lattice Boltzmann method such as limitation to uniform mesh, tie-up of mesh spacing and time interval, limitation to viscous flows. LBFS is validated by its application to simulate the viscous decaying vortex flow, the driven cavity flow, the viscous flow past a circular cylinder, and the inviscid flow past a circular cylinder. The obtained numerical results compare very well with available data in the literature, which show that LBFS has the second order of accuracy in space, and can be well applied to viscous and inviscid flow problems with non-uniform mesh and curved boundary.     

Design,Synthesis and Antitumor Activity in vitro of a Series of 3-Arylcoumarins

A new series of 7-substituted 3-arylcoumarins was designed, synthesized and evaluated as novel antitumor agents in vitro. It was found that several compounds of them exhibit activity in vitro against SK-HEP-l（hepatocellular carcinoma）, HepG2（hepatocellular carcinoma） and SGC7901（gastric carcinoma） cell lines to some extent. Moreover, compounds 5a, 5b, 6a and 6b have better activity against HeLa（cervical carcinoma） cell and their half maximal inhibitory concentration（IC50） values are less than 10μmol/L.     

基于不同时间步长时域非结构有限体积法模拟声-弹性耦合问题

介绍一种改进的时域非结构有限体积法(FVM),并将其应用于声-弹性耦合问题。在流体与固体介质中分别求解声波动方程与弹性波方程,根据交界面上的力平衡与质点振速连续条件考虑二者的相互作用。同时考虑双线性四边形单元的线性变化项及常数项,并结合常应变三角形单元处理混合网格问题。分别对三角形单元和四边形单元进行色散分析,给出声波动方程的稳定性条件。在不同介质中采用不同时间步长,提高计算效率。求解弹性波问题、声-弹性耦合问题,结果表明,改进后的方法求解声-弹性耦合问题是有效和准确的,并且具有良好的数值稳定性。     

A new lattice hydrodynamic traffic flow model with a consideration of multi-anticipation effect

We present a new multi-anticipation lattice hydrodynamic model based on the traffic anticipation effect in the real world.Applying the linear stability theory,we obtain the linear stability condition of the model.Through nonlinear analysis,we derive the modified Korteweg-de Vries equation to describe the propagating behaviour of a traffic density wave near the critical point.The good agreement between the simulation results and the analytical results shows that the stability of traffic flow can be enhanced when the multi-anticipation effect is considered.     

Design studies on the 4π γ-ray calorimeter for the ETF experiment at HIRFL-CSR

A high detection efficiency calorimeter which is used to detect γ-rays with energies from 1 MeV up to 10 MeV as well as light charged particles has been proposed.Design of the geometry,results of the crystal tests and Monte Carlo simulations are presented in this paper.The simulation results confirm that the calorimeter can obtain high detection efficiency and good energy resolution with the current designed geometry.And the calorimeter is competent for the future External Target Facility(ETF)experiments.     

New band structures in 107Ag

High spin states in ¹⁰⁷Ag are studied via the ¹⁰⁰Mo(¹¹B, 4n)¹⁰⁷Ag reaction at an incident beam energy of 60 MeV. Prompt γ-γ coincidence and DCO ratios are measured by the detector arrays in CIAE. The level scheme has been updated and a new negative band belonging to ¹⁰⁷Ag is identified. The new negative side band has been constructed and its configuration is tentatively assigned to πg_9/2 νh_11/2(g_7/2/d_5/2).