用自制仪器精确测定变温液体的粘滞系数

介绍了用恒流法自制仪器精确测定液体的粘滞系数.该自制仪器,能有效地保证底部的密封性、液体水位恒定和可操作性,还增设一个玻璃管连通器,附加一根标尺和游标使液体水位的测量精确度提高.并在接毛细管输出液体的量筒处加上光电计使测量液体流速的精确度提高,采用该仪器测定了水和乙醇两种液体在变温条件下的粘滞系数,经实验比对,所测得结果与理论值能较好地吻合.同时设计了可调换不同管径的毛细管,能快速准确地测量多种变温液体的粘滞系数.     

Two-dimensional numerical research on effects of titanium target bombarded by TEMPⅡ accelerator

Two-dimensional numerical research has been carried out on the ablation effects of titanium target irradiated by intense pulsed ion beam (IPIB) generated by TEMP II accelerator. Temporal and spatial evolution of the ablation process of the target during a pulse time has been simulated. We have come to the conclusion that the melting and evaporating process begin from the surface and the target is ablated layer by layer when the target is irradiated by the IPIB. Meanwhile, we also obtained the result that the average ablation velocity in target central region is about 10\,m/s, which is far less than the ejection velocity of the plume plasma formed by irradiation. Different effects have been compared to the different ratio of the ions and different energy density of IPIB while the target is irradiated by pulsed beams.     

脉冲激光烧蚀Ge产生等离子体特性的数值模拟

针对激光烧蚀半导体材料Ge初期的特点,建立了1维的热传导和流体动力学模型。对波长为248 nm、脉宽为17 ns、峰值功率密度为4×108 W/cm2的KrF脉冲激光在133.32 Pa氦气环境下烧蚀Ge产生等离子体的特性进行了数值模拟。结果表明：单个激光脉冲对靶的烧蚀深度达到55 nm,蒸气膨胀前端由于压缩背景气体产生压缩冲击波, 波前的速度最大,温度很高。从不同时刻的电离率分布图中得出,在靶面附近区域,Ge的1阶电离始终占优势;在中心区域,脉冲作用时间内,Ge的2阶电离率比1阶电离率大,脉冲结束后,Ge的2阶电离率下降,1阶电离率逐渐变大。     

用加权残值法求压杆的临界载荷

用加权残值法求压杆的临界载荷刘悦藏（河北工学院材料力学教研室,天津３００１３２）加权残值法是一种求解微分方程的方法。它不是严格地求微分方程的解析解,而是直接从微分方程得出问题的近似解。与其它数值法相比,它没有完全抛弃已有的理论解。由于此法原理简单、方...     

强流脉冲电子束表面改性的物理模型及数值模拟

 推导出了强流脉冲电子束处理过程的应力场方程，利用数值模拟，得到了温度场和应力场的分布曲线，分别给出了熔化深度、升降温的速率及温度梯度的大小，准静态应力和热应力波的幅值、应力波的传播及反射过程，利用数值模拟结果对实验中观察到的实验现象熔化深度、材料表层及次表层数微米范围内组织结构的变化及数百微米的硬度提高等给出了解释。     

Dust Charging in Electronegative SiH4 Plasmas

We theoretically investigate the dust charging in electronegative silane (SiH4) plasmas, taking into account the effects of UV photodetachment. It is found that UV photodetachment could significantly lower the dust negative charge and even makes dust grains be positively charged under some special conditions. In addition, the other parameters, involving the negative ion and dust number densities, electron temperature and dust radius, have great effects upon the dust charging.     

新工科背景下“工匠精神”融入高分子专业课程的探索与实践

新工科和中国制造2025对高等教育提出了新的要求,为了培养适应经济发展的创新型人才,本文以《高分子物理》为例,在确立了“工匠精神”核心思想基础上,通过修订教学大纲、提升教师自身的匠人品质、改革教学手段和方法、改革考试考核方式等措施,对新工科背景下“工匠精神”融入专业课程进行尝试,建立了一套基于“工匠精神”培育的《高分子物理》课堂教学新模式,并取得了有益的结果。     

Propagation of Plasma Generated by Intense Pulsed Ion Beam Irradiation

Taking the calculation results based on the established two-dimensional ablation model of the intense-pulsed-ionbeam （IPIB） irradiation process as initial conditions, we build a two-dimensional hydrodynamic ejection model of plasma produced by an IPIB-irradiated metal titanium target into ambient gas. We obtain the conclusions that shock waves generate when the background pressure is around 133 mTorr and also obtain the plume splitting phenomenon that has been observed in the experiments.     

Numerical study on the characteristics of nitrogen discharge at high pressure with induced plasma

Based on the fluid theory of plasma, a model is built to study the characteristics of nitrogen discharge at high pressure with induced argon plasma. In the model, species such as electrons, N2+, N4+, Ar+, and two metastable states (N 2(A3∑u+), N2 (a1 ∑u-)) are taken into account. The model includes the particle continuity equation, the electron energy balance equation, and Poisson抯equation. The model is solved with a finite difference method. The numerical results are obtained and used to investigate the effect of time taken to add nitrogen gas and initially-induced argon plasma pressure. It is found that lower speeds of adding the nitrogen gas and varying the gas pressure can induce higher plasma density, and inversely lower electron temperature. At high-pressure discharge, the electron density increases when the proportion of nitrogen component is below 40%, while the electron density will keep constant as the nitrogen component further increases. It is also shown that with the increase of initially-induced argon plasma pressure, the density of charged particles increases, and the electron temperature as well as the electric field decreases.     

纯电子等离子体的宏观非寻常模稳定性

本文利用冷流体模型及麦克斯韦方程研究了磁约束在圆柱形导体容器内的纯电子等离子体的宏观非寻常模稳定性,导出了电磁性槽纹扰动(k_Z=0)下的普遍本征方程。数值研究了电子密度为矩形分布和钟形分布下等离子体的稳定性。