Damping of Geodesic Acoustic Mode by Trapped Electrons

We study the Landau resonance between geodesic acoustic mode（GAM） and trapped electrons as a GAM’s collisionless damping. The assumption of ˉωde 〈〈ωbeis adopted.The damping rate induced by trapped electrons is found to be an increasing function of q. In low q range, circulating-ion-induced damping rate is larger than that induced by trapped electrons.As q increases, the latter becomes larger than the former. The reason is that trapped electrons’ resonant velocity is close to vtefrom the lower side, whiles circulating ions’ resonant velocity gets bigger further from vti. So the number of resonant trapped electrons increases, whiles the number of resonant circulating ions decreases. The amplitude of damping rate induced by trapped electrons in the edge plasma can be comparable to that induced by circulating ions in the low q range.Another phenomenon we found is that in the chosen range of, the damping caused by trapped electrons has a maximum value at point εq for different q. The reason is that as is close to q,trapped electorns’ resonant velocity is close to vte.     

额济纳绿洲冬春月入境水量配置

根据狼心山水文站流量,利用数理统计和相关分析法,估算了黑河水量常规调度以来冬春月(11月至翌年3月)进入额济纳绿洲的水量。结果表明:冬春月狼心山径流量年际变化较小,约占全年总量的34%;25%、50%、75%保证率下,冬春月额济纳绿洲补给水量分别为1.93亿、1.45亿、0.86亿m~3。结合生态需水量,提出适用于额济纳绿洲的冬春月水量配置方案:25%保证率来水条件下,东河、西河水量可按照57?43比例进行下泄;50%保证率来水条件下,东河、西河基本按照61?39的比例分流;75%保证率来水条件下,东河、西河下泄水量可按照70?30的比例分配。     

改进的WinSock实现压气站仿真培训器内的通讯

通常大型仿真系统由多台计算机组成,各计算机完成系统的一个模块,而各计算机之间的数据是相互共享的。多台计算机间的数据通讯是一个比较普遍的问题,Windows Socket是解决通讯的常用方法。但在该文讨论的燃气轮机——离心式压缩机组仿真培训器仿真系统中,客户端的输气管道系统是由iFix操作系统完成的,但iFix不能很好地支持Socket,因此该文结合Socket和DDE技术通过Excel中转解决了服务器到与iFix管道系统的通讯问题。而且,改进了Socket发送和接收数据函数,解决了Socket自身存在的通讯堵塞问题。     

Effects of Finite Aspect Ratio and Noncircular Plasma Flux Surface on Electron Temperature Gradient Driven Modesd

A gyrokinetic model with integral eigenmode equations is developed based on the local equilibrium of shaped tokamak plasmas. Effects of main geometric parameters （finite aspect ratio, elongation, triangularity, and Shafranov shift gradient） on the electrostatic electron temper- ature gradient （ETG） driven modes are investigated numerically. It is found that the finite aspect ratio has a general stabilizing effect, while the elongation can be either stabilizing or destabilizing, depending on the poloidal wavelength of the mode and other parameters. It is shown that a low aspect ratio enhances the stabilizing effect of elongation, and weakens its destabilizing effect as well.     

小数据量法计算最大Lyapunov指数的参数选择

为避免人为选择平均周期和线性区间所带来的计算不准,在分析小数据量法计算最大Lyapunov指数的基础方法之上,提出平均周期和计算最大Lyapunov指数线性区域的确定方法。仿真算例表明,所提出的方法可以快速便捷地实现小数据量法计算最大Lyapunov指数。     

碰摩转子-轴承系统的随机分岔与混沌特性分析

为研究碰摩转子的随机分岔及混沌特性,建立了白噪声下碰摩转子-轴承系统的动力学方程。利用数值积分法对方程求解,以最大Lyapunov指数为指标,并结合分岔图、轴心轨迹、Poincare映射分析了转子系统的非线性特性。结果表明,在拟周期及邻近周期解和转速较大的一定区间,随机扰动对转子有显著的影响;转子转速较大时,随机扰动的强度越大,其影响越明显,并且随机扰动对转子非线性响应具有一定的抑制作用。