无机陶瓷膜纯化杏鲍菇多糖

为了提高杏鲍菇多糖的含量,用0.2μm的无机陶瓷膜对杏鲍菇多糖进行纯化,结果表明在25℃,0.02—0.08M Pa压差操作条件下,纯化后的杏鲍菇多糖含量为62%,并且可以除去大部分不溶物和蛋白质胶体等大分子杂质。采用漂洗、碱洗、酸洗,可使膜的清水通量恢复率达到95%以上。     

青海产6种凤毛菊属植物微量元素分析比较

为了比较青海产6种凤毛菊属植物微量元素的含量,应用火焰原子吸收光谱法分析了青海产6种凤毛菊属植物中微量元素的含量.结果表明,水母雪莲中钙和锰的含量最高分别为8148.58mg/kg和312.55mg/kg,唐古特雪莲中铁和锌的含量最高达5798.98、46.22mg/kg.重齿凤毛菊中铜的含量最高为6.09mg/kg....     

高频电压调制对同步运动的影响

从系统的扰动Hamiltonian出发, 在经典力学框架内小振幅近似下, 把粒子的纵向运动方程化为Mathieu方程, 指出了由于扰动的存在, 准等时同步加速器出现了一系列新的共振线。用摄动法导出了一阶不稳定区的边界曲线和禁带宽度; 指出了当粒子穿越禁带后的振幅与同步加速器的两个不稳定点相位相等时, 系统处于临界状态; 并由此导出了高频电压调制振幅的临界值。In the classical mechanics frame and small amplitude approximation, the longitudinal motion equation of the particle was reduced to the Mathieu equation based on the perturbed Hamiltonian. It was pointed out that there is a series of new resonance lines in quasi isochronous synchrotron by the perturbation. The boundary curve and the stop width for order instability zone one were derived by the method of perturbabtion. Also it was pointed that the system is at the critical point when the phase becomes equal to the phase of the instable point for the synchrotron after it crossed the stop band, and the critical condition of the high frequency voltage modulation was derived.     

正电子面沟道辐射的非线性特征

经典物理学指出,在电磁场中作加速运动的带电粒子将不断向外辐射能量.在晶体沟道中运动的带电粒子也不例外,晶格场可以使带电粒子的辐射能量达到很高.对于10MeV的正电子,辐射能量可达keV量级.粒子在沟道中的运动行为决定于粒子晶体的相互作用势,常用的相互作用势有Lindhard势、Moliere势和正弦平方势.由于粒子在沟道中的运动行为十分类似于震荡器中运动的自由电子,可望把沟道辐射改造为Χ射线激光或γ射线激光.从Lindhard势出发,将其展开到四次项,在经典力学框架内,粒子的运动方程可以化为含立方项的二阶非线性微分方程,并利用Jacobian椭圆函数和第一类全椭圆积分解析地表示了系统的解和粒子运动周期,导出了正电子面沟道辐射的瞬时辐射强度、平均辐射强度和最大辐射频率,指出了利用沟道辐射作为γ激光的可能性.     

重频纳秒高压脉冲下变压器油击穿特性的实验研究

介绍了重频纳秒高压脉冲下变压器油绝缘特性研究的现状和成果。进行了重频（1 Hz～1 kHz）纳秒高压脉冲下25#变压器油击穿特性的实验研究。实验发现相对于单次纳秒脉冲,重频脉冲下25#变压器油的击穿场强与频率相关,频率提高,击穿场强降低,但不是线性关系,在频率超过100 Hz时变压器油的击穿场强变化较小,在10~100 Hz时变压器油的击穿场强迅速下降。初步总结了重复频率、脉冲宽度和击穿场强的关系,对重频脉冲下变压器油的击穿机理进行了初步的探讨。     

ION FLUX BEHAVIOR IN HIGH DENSITY PLASMAS

The available electron cyclotron resonance plasma sources have been simulated in two-dimensional configuration space (Z, R) and three-dimensional velocity space (V_z, V_r, V_θ). Using a hybrid model, we treat ions as particles and electrons as fluid. The simulation is specified for plasma parameters of the available apparatus and is focused on the ion flux distributions. For a set of given operating conditions, the spatial distributions of electron temperature, plasma potential, plasma density, ionization rate and the contours map of distributions of particles in different volume cells in velocity space are obtained; statistics on ions that hit the bottom surface are also reported. The distributions of ion flux vectors on different cross-section planes in the plasma are given, and the phenomena of large radial diffusione of ions across magnetic force lines are also demonstrated. Finally, the influences of microwave power and neutral gas pressure on the distributions of ion flux vectors on ZR-plane, ion flux radial distributions and ion currents to all walls have been studied.     

LD抽运被动调Q固体激光器的脉冲稳定性

报道了二极管激光抽运Cr,Nd∶YAG被动调Q Nd∶YVO4 1064 nm激光输出.为了提高被动调Q激光的输出稳定性,谐振腔采用长腔,增益介质位于谐振腔中间位置.实验中获得了稳定的被动调Q激光输出.在最高入射抽运功率为17.5 W时,脉冲重复频率达到71.3 kHz,脉冲宽度为0.4 μs.调Q脉冲幅度不稳定性低于±10%,脉冲时间波动性低于±3.5%.     

Entanglement Transfer from Two-Mode Squeezed Vacuum State Field to Two Spatially Separated Atoms in Two-Photon Processes

We investigate the influence of the Stark shift on the entanglement transfer from the two-mode squeezed vacuum state field to two spatially separated atoms in two-photon processes. Our results show that the Stark shift plays an important role in such entanglement transfer. We find that when the Stark shift parameter r is small, the degree of entanglement between the two atoms increases with the increasing of the squeezing parameter ξ first, and after achieving its maximal value, the degree of entanglement will decrease to zero with the increasing of ξ; while for big r, E will increase with the increasing of ξ.     

Entanglement reciprocation between two charge qubits and two-cavity field

We propose a simple scheme to generate two-mode entangled coherent state in two separated cavities and realize the entanglement reciprocation between the superconducting charge qubits and continuous-variable system. By measuring the state of charge qubits, we find that the entanglement of two charge qubits, which are initially prepared in the maximally entangled state, can be transferred to the two-cavity field, and at this time the two-cavity field is in the entangled coherent state. We also find that the entanglement can be retrieved back to the two charge qubits after measuring the state of the two-cavity field.      

Nd:YAG激光器光栅式扫描预处理的计算模拟与优化分析

 采用计算模拟的方法,研究了光栅式扫描预处理的扫描方式以及脉冲能量波动、定位误差对预处理效率的影响。研究发现,脉冲能量波动及其定位误差使预处理效率降低,同时其影响与扫描方式之间存在相互调制作用,因此可以通过选择合适的扫描方式以及扫描间隔来优化预处理流程,提高预处理效率。此外发现,光斑呈等边三角形排列时的预处理效率优于正方形。