一类非定常对流占优扩散问题差分-流线扩散法的后处理

讨论了一类非定常对流占优扩散方程的差分-流线扩散格式(FDSD),利用插值后处理技术,提高了特殊网格下该FDSD格式在双线性元空间的精度,从而按L∞(L2(Ω) 模达到最优．     

Minimax Theorems Involving Two Functions and Strictly Monotone Transformations of Their Values

Two two-function minimax theorems are proved.The concavity-convexity conditions of the twofunctions involve strictly monotone transformations and mixing of the values of the two functions,and aredescribed by the inequalities as upward and weakly downward conditions.     

高能闪光照相对电子束参数的要求

对高能闪光机光源性能用Monte-Carlo方法模拟研究发现：并非击靶电子束半径越小、发射度越低, 闪光机的照相性能就会越好. 研究结果表明：为了使闪光照相图像视面上照射量分布比较均匀, 对束半径与电子束归一发射度有一个联合限制, 对于20MeV闪光机, 如果击靶电子束有效半径是0.12cm, 那么仅当束归一发射度≥550cm.mrad时,在2°内的照射量不均匀性才小于5%.     

The effect of surface crystalline layers on asymmetric off-diagonal magnetoimpedance in field-annealed CoFeSiB amorphous ribbons

The off-diagonal magnetoimpedance in field-annealed CoFeSiB amorphous ribbons was measured using a pick-up coil wound around the sample. One side of a ribbon was etched in hydrofluoric acid solution during various times in order to change the thickness of the surface crystalline layer appearing after annealing. The asymmetric two-peak field dependence of the off-diagonal impedance was observed for all samples. The evolution of the off-diagonal magnetoimpedance with the change in the ribbon thickness is analyzed.     

多气隙电阻板室抗辐照性能研究

给出了为RHIC-STAR飞行时间探测器设计的多气隙电阻板室(MRPC)的辐照实验结果. 实验采用100mCi⁶⁰Co γ源, 采用不同的剂量率对MRPC进行辐照. 一个室在大剂量率2.87×10^－2Gy/h下辐照了24h后, 其性能如噪声计数率, 暗电流等均大大退化. 另一个室在相对低剂量率5.31×10^－4Gy/h下辐照了530h, 其性能没有见到任何变坏. 实验的目的是为了了解这种探测器在几年的运行中经过大剂量的辐照后的性能变化情况.     

海藻酸钠/大豆蛋白共混凝胶微球的结构

利用钙离子交联海藻酸钠／大豆分离蛋白共混溶液，制得海藻酸钠／大豆分离蛋共混凝胶微球．结果表明，海藻酸钠和大豆分离蛋白质量配比的不同以及各组分间相互作用的变化，微球呈现不同的微观结构．将微球干燥后置于水中溶胀，微球的尺寸无法回复到干燥前的尺寸，这是由于真空干燥处理使水分子挥发，促进微球内组分间形成了强的氢键作用所致．此外，用碱处理该共混微球，发现由于大豆分离蛋白溶解以及部分钙离子被置换析出，微球塌陷且内部形成了大孔．     

曾山对苏维埃政权建设的贡献

曾山在苏维埃政府工作期间,加强了苏维埃政权的组织、政治、思想、作风建设,严惩腐败分子,抵制批评了肃反工作中的“左”的错误;制定了土地分配及抗债的有关条例;加强了财政经济建设,促进经济发展提高生产,服从服务革命战争;他深入发动群众参加革命,统一地方武装,并把大批地方武装输送给主力红军。积极配合主力红军进行反“围剿”战争,保卫苏维埃政权。为建立、捍卫和发展苏维埃政权立下了丰功伟绩。     

A Relaxation Scheme for Solving the Boltzmann Equation Based on the Chapman-Enskog Expansion

Abstract In [16] a visco-elastic relaxation system, called the relaxed Burnett system, was proposed by Jinand Slemrod as a moment approximation to the Boltzmann equation. The relaxed Burnett system is weaklyparabolic, has a linearly hyperbolic convection part, and is endowed with a generalized eotropy inequality. Itagrees with the solution of the Boltzmann equation up to the Burnett order via the Chapman-Enskog expansion. We develop a one-dimensional non-oscillatory numerical scheme based on the relaxed Burnett system forthe Boltzmann equation. We compare numerical results for stationary shocks based on this relaxation scheme,and those obtained by the DSMC (Direct Simulation Monte Carlo), by the Navier-Stokes equations and bythe extended thermodynamics with thirteen moments (the Grad equations). Our numerical experiments showthat the relaxed Burnett gives more accurate approximations to the shock profiles of the Boltzmann equationobtained by the DSMC, for a range of Mach numbers for hypersonic flows, th     

等离子体中Langmuir波、横波和离子声波相互作用过程的孤立子行为

我们用Zakharov方程描述等离子体中Langmuir波、横波和离子声波的非线性相互作用,通过研究系统稳态的Sagdeev势的性质,讨论了该系统中孤立子可能存在的条件;同时和体系的极小能量状态相联系,构造了体系的Liapunov泛函,研究了孤立子的Liapunov稳定性。我们所采用的方法是完全非线性的,得到的稳定性判据在横波和Langmuir波解耦情况下退化为文献[8]的结果。 关键词：     

重离子治疗计划系统的构想

对重离子柬治癌的优势进行简要的回顾，并着重介绍了用于重离子放射治疗的治疗计划系统。治疗计划系统是一套软件系统，不同的硬件设施应有与其相匹配的软件系统，即治疗计划系统。在此基础上，针对兰州重离子加速器的特点提出一些关于治疗计划系统方面的构想。After a brief review concerning the advantages of heavy ions in radiotherapy, more interests are concentrated on treatment planning system （TPS） for heavy ion radiotherapy. Compared to the hardware devices such as accelerator and beam delivery system, the TPS is a set of software system, and different therapy facilities require their corresponding TPSs. Based on the specialities of the Heavy Ion Research Facility in Lanzhou （HIIRFL）, some suggestions on the TPS for tumor therapy at HIRFL finally are given.