一台14.5GHz新型高磁场高电荷态ECR离子源

自行研制成功一台14.5GHz新型高磁场高电荷态电子回旋共振(ECR)离子源.描述了该离子源结构特点、参数优化及其磁场分布,并给出了调试测量结果.该离子源轴向磁镜场在轴线上的最高磁场可达1.5T,六极永磁体在弧腔内表面磁场可达1.0T.经初步调试,可得到0⁷+140eμA,Ar¹¹+185eμA,Xe²⁶⁺50eμA.所得结果与1998年国际上最好的ECR离子源进行了比较.     

选通式象增强器的新型导电基底

本文介绍了采用光刻技术制备的一种新型的导电基底,它的面电阻≤ 10Ω,透过率约为 89%.在该基底上研制出的选通式象增强器,可实现选通时间在 ns级以上的高速选通,适用于微光、瞬时多通道高速光谱分析系统和高速摄影系统.     

物理实验中温度测量的改进与应用

本分析了物理实验中玻璃温度计进行测温所存在的问题,根据半导体温度传感器工作原理设计并制作了一种新型的电子测温仪,该仪器具有精度高、响应快、读数方便以及便于二次开发等优点。     

少周期飞秒脉冲在氩晶体中高次谐波产生的最优控制

采用第一性原理的含时密度泛函理论,系统地研究了少周期高强度飞秒脉冲驱动氩晶体固体产生孤立阿秒脉冲的脉宽、强度随驱动脉冲波形、偏振方向的变化规律.结果发现：1)固体产生的孤立阿秒脉冲对驱动脉冲波形和偏振十分敏感;2)在最优的驱动脉冲波形和偏振情况下,固体产生的孤立阿秒脉冲的宽度与原子气相比没有明显增大的同时,其强度比原子气产生的强度大了接近4倍.结果对固体孤立阿秒脉冲产生及其调控的探索是有帮助的.     

Nondestructive Rapid Identification of Soybean Varieties Using Hyperspectral Imaging Technology

Journal of Applied Spectroscopy - Hyperspectral imaging technology was used to classify four types of soybean varieties. The reflectance spectra of four varieties of soybeans were extracted from...     

Analytic soliton solutions of cubic‐quintic Ginzburg‐Landau equation with variable nonlinearity and spectral filtering in fiber lasers

In fiber lasers, the study of the cubic‐quintic complex Ginzburg‐Landau equations (CGLE) has attracted much attention. In this paper, four families (kink solitons, gray solitons, Y‐type solitons and combined solitons) of exact soliton solutions for the variable‐coefficient cubic‐quintic CGLE are obtained via the modified Hirota method. Appropriate parameters are chosen to investigate the properties of solitons. The influences of nonlinearity and spectral filtering effect are discussed in these obtained exact soliton solutions, respectively. Methods to amplify the amplitude and compress the width of solitons are put forward. Numerical simulation with split‐step Fourier method and fourth‐order Runge‐Kutta algorithm are carried out to validate some of the analytic results. Transformation from the variable‐coefficient cubic‐quintic CGLE to the constant coefficients one is proposed. The results obtained may have certain applications in soliton control in fiber lasers, and may have guiding value in experiments in the future.

     

Thermally induced spin polarization and thermal conductivities in a spin–orbit-coupled two-dimensional electron gas

The thermal conductivities and spin polarization induced by the temperature gradient are investigated in a Rashba spin–orbit-coupled two-dimensional electron gas. In this spin–orbit-coupled system in the presence of nonmagnetic or magnetic electron–impurity scattering, the Wiedemann–Franz law still holds. However, the spin polarization induced by the temperature gradient strongly depends on the property of impurities. The components of spin accumulation both perpendicular and parallel to the direction of the temperature gradient, and the thermally induced charge Hall conductivity may be nonzero for magnetic disorders.     

Understanding light scalar meson by color-magnetic wave function in QCD sum rule

In this paper, we study the 0⁺ nonet mesons as tetraquark states with interpolating currents inspired by the color-magnetic wave function. This wave function is the eigenfunction of an effective color-magnetic Hamiltonian with the lowest eigenvalue, meaning that the state depicted by this wave function is the most stable one and is the most probable to be observed in experiments. We perform an OPE calculation up to dimension-eight condensates and find that the best QCD sum rule is achieved when the current inspired by the color-magnetic wave function is a proper mixture of the tensor and pseudoscalar diquark-antidiquark bound states. Compared with previous results, to sigma(600) and kappa(800), our results appear better, due to larger pole contribution. The direct instanton contributions are also considered, which yields a consistent result with previous OPE results. Finally, we also discuss the h￠ \eta{^\prime} problem as a possible six-quark state.     

Precision Penning trap mass measurements of rare isotopes produced by projectile fragmentation

The low-energy beam and ion trap facility LEBIT at NSCL/MSU is at present the only facility where precision experiments are performed with stopped rare isotope beams produced by fast-beam fragmentation. LEBIT combines high-pressure-gas stopping with advanced ion manipulation techniques to provide brilliant low-energy beams. So far these beams have mainly been used for mass measurements on short-lived rare isotopes with a 9.4T Penning trap mass spectrometer. Recent examples include ^70m Br , located at the proton dripline, ³²Si and the iron isotopes ^63-65Fe . While the measurement of ³²Si helps to solve a long-standing dispute over the validity of the isobaric multiplet mass equation (IMME) for the A = 32 , T = 2 multiplet, the mass measurements of ^65m,g Fe marked the first time a nuclear isomeric state has been discovered by Penning trap mass spectrometry.