对LVDSMC方法的改进(英文)

最近,Homolle和Hadjiconstantinu提出了新的粒子模拟方法———LVDSMC方法[1],该方法采用了减少方差的思想从而提高了低速流动问题中的计算效率。本文针对LVDSMC方法提出两点改进:第一,除了方法中原来已采用的偏差粒子,在计算近自由分子流问题时建议额外地采用一些辅助粒子,从而可以约束计算过程中原始算法在生成偏差粒子时计算误差的累积效应;第二,提出一个可选的用于计算潜在Maxwell Boltzmann分布函数中的速度参数的增量,从而使得表面的应力及热流的计算变得简单。

Coupling of thermocapillary convection and evaporation effect in a liquid layer when the evaporating interface is open to air

The coupling mechanism of thermocapillary convection and evaporation effect in evaporating liquids was studied experimentally. The experiments were carried out to study a thin evaporating liquid layer in a rectangular test cell when the upper surface was open to air. By altering the imposed horizontal temperature differences and heights of liquid layers, the average evaporating rate and interfacial temperature profiles were measured. The flow fields were also visualized by PIV method. For comparison, the experiments were repeated by use of another two non-evaporating liquids to study the influence of evaporation effect. The results reveal evidently the role that evaporation effect plays in the coupling with thermocapillary convection.

牵拉力对共培养的表皮干细胞及成纤维细胞迁移行为的影响

<正>背景:创面愈合是一个复杂的动态过程,是细胞之间、细胞与细胞外基质及细胞因子间相互影响和协同作用的结果。另外,大量相关研究表明机械应力可以诱导组织细胞增殖,促进创面愈合。因此创面愈合也是一个典型的力学-生物学耦合过程,但力学刺激促进创面愈合的细胞/分子的调控机制目前尚不清楚。皮肤由多种细胞组成,通过牵张皮肤等在体方法难以区分其中某类细胞对外界力学刺激的单独响应以及不

Study of the aberrations of the IMP heavy ion microbeam irradiation system

A high energy heavy ion microbeam irradiation system is constructed at the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS). A quadrupole focusing system, in combination with a series of slits, has been designed here. The IMP microbeam system is described in detail. The intrinsic and parasitic aberrations associated with the magnets are simulated. The ion beam optics of this microbeam system is investigated systematically. Then the optimized initial beam parameters are given for high spatial resolution and high hitting rates.

分离鉴别重丰中子核的重要手段：X-γ符合技术

本文简单地介绍远离β-稳定线重质量丰中子核的合成和研究的科学意义。扼要叙述X-γ符合技术(元素指定方法)。指出X-γ符合方法在远离β-稳定线重丰中子核研究中的重要作用。借助于X-γ方法先后研究了一些如~(175)Er、~(197)Os、~(229)Ra、~(238)Th和~(186m)Ta等重丰中子核。

并行设备总线嵌入式控制系统设计

为了对物理实验装置的远程监控和访问,将采用32位内核芯片技术结合CPLD逻辑时序编程来设计3U VME设备总线系统。S3C4510B是三星公司针对网络应用而设计的CPU,本身带有100Mbps网络控制器,而由于Clinux系统拥有完善的TCP/IP协议,因此二者的结合为用户提供了强大的网络服务功能。该系统利用嵌入式网络和并行总线技术可稳定可靠地实现数据的快速获取与给定。

~(19)F+~(27)Al耗散反应中双核系统的转动与形变

测量了19F+27Al耗散反应产物B,C,N,O,F和Ne的激发函数,入射束流的能量从110．25MeV 到118．75MeV,能量步长为250keV．从产物的能量自关联函数中提取了反应中所形成的中间双核系统的转动惯量,与相粘模型计算的刚体转动惯量相比较,结果表明形成的双核系统有大的形变．

CSR的辐射屏蔽设计(英文)

CSR(cooling storage ring)按计划将于2005年底建成调束,届时从~(12)C到~(238)U的重离子将可以分别被加速到900和400MeV的能量。HIRFL(兰州重离子加速器Heavy Ion Research Facility in Lanzhou)将用作CSR的注入器。为了CSR的屏蔽设计,本文利用现有的实验数据计算了由于束流损失产生的中子及其能谱、角分布,同时也估算了屏蔽体外表面的中子剂量、环境中子剂量及天空返照中子剂量。在源项计算中使用了400MeV/u~(12)C+Cu反应的中子产额、能谱、角分布的实验数据。计算表明,CSR对环境剂量影响最大的是天空返照中子。