Thermocapillary Migration of Deformable Bubbles at Moderate to Large Marangoni Number in Microgravity

Using the level-set method and the continuum interface model, the axisymmetric thermocapillary migration of gas bubbles in an immiscible bulk liquid with a temperature gradient at moderate to large Marangoni number is simulated numerically. Constant material properties of the two phases are assumed. Steady state of the motion can always be reached. The terminal migration velocity decreases monotonously with the increase of the Marangoni number due to the wrapping of isotherms around the front surface of the bubble. Good agreements with space experimental data and previous theoretical and numerical studies in the literature are evident. Slight deformation of bubble is observed, but no distinct influence on the motion occurs. It is also found that the influence of the convective transport of heat inside bubbles cannot be neglected at finite Marangoni number, while the influence of the convective transport of momentum inside bubbles may be actually negligible.

高灵敏度等时性回旋加速器束流相位测量系统

介绍了兰州重离子加速器(HIRFL)束流相位测量装置．该装置基于双平衡混频原理,采用了高频信号混频滤波技术,具有较高的测量灵敏度．通过安装在加速器中的容性感应探针探测等时性回旋加速器束流相位历程,在调束中获取等时场信息并对磁场进行优化,从而提高引出束流强度和束流品质是非常重要的．该装置通过等时场相位优化实验,检验了相位测量数据的可靠性,测量精度达到±0．5°．

January to August temperature variability since 1776 inferred from tree-ring width of Pinus tabulaeformis in Helan Mountain

IEECAS SKLLQG

碳离子辐照哺乳动物细胞引起的旁观者效应

用经过碳离子辐照V79细胞的条件培养基(Irradiatedconditionedmedium,简称ICM)和与受照射细胞共同培养两种方法,研究了未受照射细胞的旁观者效应。结果表明,ICM法可以明显降低未受照射细胞的克隆形成率;受照射细胞与未受照射细胞共同培养一段时间后,细胞克隆形成率比假定没有旁观者效应时的预期值低,细胞微核率和hprt(次黄嘌呤磷酸核糖基转移酶)基因位点突变率与预期值基本相同。推测受照射细胞可能释放出了能对未受照射细胞生长产生毒性的因子,这种因子对未受照射细胞没有明显的致微核和致突变作用。

剩余气体束流剖面探测系统的初步研制

介绍了剩余气体束流剖面探测系统的工作原理和设计依据,描述了所设计的系统结构并进行了初步实验,证明了利用剩余气体探测束流剖面的方法是可行的。