网格与高精度差分计算问题

研究NS方程差分求解时来流雷诺数、计算格式精度和计算网格之间的关系．给出了判定空间三个方向上的粘性贡献在给定雷诺数、格式精度和网格下是否能够正确计入的估计方法．指出在NS方程的二阶差分方法的数值模拟中,由于物面法向采用了压缩网格技术,物面附近的网格间距很小,该方向上的粘性贡献可被计入．但是如果流向和周向的网格较粗,相应的差分方程中的粘性贡献可能落入截断误差相同的量级,因此在精度上等于仍是求解略去流向和周向粘性项的薄层近似方程．指出,高阶精度的差分计算格式,可以避免对网格要求苛刻的困难．并进一步讨论了建立高阶精度格式的问题,提出了建立高阶精度格式应该满足的原则：耗散控制原则以及色散控制原则．为了避免激波附近可能出现的微小非物理振荡,建议发展混合高阶精度格式,即在激波区,采用网格自适应的NND格式,在激波以外的区域,采用按上述原则发展的高阶格式．     

Enhancement of Dielectronic Recombination by External Electromagnetic Fields

The enhancement of the dielectronic recombination rate of lithiumlike Ne⁷⁺ and O⁵⁺ ions by external electromagnetic fields has been measured at the storage ring CRYRING. The energy range covered all 1s ²2pnl dielectronic recombination resonances attached to the 2s→2p core excitation. Electric fields up to 1436 V/cm were applied in the Ne⁷⁺ experiment and the saturation of the enhancement with increasing electric field could clearly be seen. In the O⁵⁺ experiment the enhancement was studied as a function of the Rydberg quantum number n.

     

SU(3)夸克模型中的Ω束缚态

从夸克 -反夸克通过介子场耦合的模型出发研究了 (ΩN) LST是否存在束缚态的问题 .计算表明当考虑了s u(s d)湮没为K 介子的机制后 ,(Ω N)0 2 1 2 是有可能形成结合能较大的束缚态     

BSA Hybrid Synthesized Polymer

Bovine serum albumin （BSA）, a naturally occurring biopolymer, was regarded as a polymeric material to graft to an acrylic acid （AA）-N-vinyl pyrrolidone （NVP） copolymer to form a biomacromolecular hybrid polymer. The hybrid polymer can be blended with polyethersulfone （PES） to increase the hydrophilicity of the PES membrane, which suggested that the hybrid polymer might have a wide application in the modification of biomaterials.     

单纯形上的q-Stancu多项式的最优逼近阶

构造了单纯形上的多元q-Stancu多项式,它是著名的Bernstein多项式和Stancu多项式的推广.建立该类多项式逼近连续函数的上、下界估计,进而给出其对连续函数的最优逼近阶(饱和阶)及其特征刻画.此外,还研究了该类多项式逼近连续函数的饱和类.     

从文献分析看物理学科领域的发展重点

文章从文献分析的角度，首先研究了美国、英国政府确定的物理学重点研究领域；其次利用美国科学情报研究所的科学引文热门论文数据库，分析了世界物理学及其交叉学科的热点、新兴的研究前沿和快速突破的领域；最后，提出了分析总结意见。     

Formation of D- by double radiative recombination of D+

We have investigated double radiative recombination of D⁺ ions stored in CRYRING by searching for the formation of D^- in the electron cooler. An upper limit for the double electron recombination rate coefficient and a ratio of this coefficient over the single electron radiative recombination rate coefficient of (3.8 ± 1.5) × 10^-8 are obtained experimentally. Theoretical calculations of the rates and a discussion in comparison with double photoionization of H^- are given. This revised version was published online in August 2006 with corrections to the Cover Date.     

A novel traceless route to synthesize 3,5-disubstituted-1,2,4-triazoles on PEG6000

A novel traceless route to 3,5-disubstituted-1,2,4-triazoles has been described, which allows the incorporation of two elements of diversity. This method provided a library of 3,5-disubstituted-1,2,4-triazoles with high yields and purity.     

Synthesis of novel fullerene α-amino acid conjugates

Aspartic acid and glutamic acid with protectedα-amino andα-carboxyl groups had been used to react with the activated hydroxyl group of N-substituted 3,4-fullero pyrrolidine.The products were deprotected,affording two monofullereneα-amino acids,monofullerene aspartic acid(mFas)and monofullerene glutamic acid(mFgu).Then a bifullerene glutamic acid conjugate (bFguC)was synthesized by reaction of mFgu containing protected amino group with N-substituted 3,4-fullero pyrrolidine.     

About Operator Weighted Shift

Abstract Let H be a complex seperable Hilbert space and ~（Jt~） denote the collection of bounded linear operators on H. For an operator in L（H）, rad{A}＇ denotes the Jacobson radical of the commutant of A. This paper characterizes the similarity of strongly irreducible operator weighted shift in terms of {A}＇/rad{A}＇. Moreover, we suggest some ways to determine when an operator weighted shift is strongly irreducible and when its commutant is commutative.