Effects of Substrate Temperature on Helium Content and Microstructure of Nanocrystalline Titanium Films

Helium-charged nanocrystalline titanium films have been deposited by HeAr magnetron co-sputtering. The effects of substrate temperature on the helium content and microstructure of the nanocrystalline titanium films have been studied. The results indicate that helium atoms with a high concentration are evenly incorporated in the deposited titanium films. When the substrate temperature increases from 60℃ to 350℃ while the other deposition＇parameters are fixed, the helium content decreases gradually from 38.6 at.% to 9.2at.%, which proves that nanocrystalline Ti films have a great helium storage capacity. The 20 angle of the Bragg peak of （002） crystal planes of the He-charged Ti film shifts to a lower angle and that of （100） crystal plane is unchanged as compared with that of the pure Ti film, which indicates that the lattice parameter c increases and a keeps at the primitive value. The grain refining and helium damage result in the diffraction peak broadening.     

Kaehler乘积流形中的半斜子流形

半斜子流形是全纯子流形和全实子流形的推广.主要讨论了Kaehler乘积流形中的乘积半斜子流形,并对其分类;再推广到一般的不变半斜子流形的情况 ,并对其分类.在研究上述情况时,还讨论了其中的特殊情况 ,并对其分类.     

增强型延迟反馈法控制低维混沌系统的解析研究

基于时间延迟反馈控制混沌系统的方法,提出一种增强型控制方案,并利用分析延迟系统产生Hopf分支条件的方法,给出这种方案控制低维连续自治混沌系统时,在达到控制目标的条件下,控制参数的一般解析关系.将这一方案和分析方法应用到两个混沌模型中,结果表明:采用修正的方案可以明显地改善控制混沌的效果和质量;解析分析的结果与实际数值计算的结果一致. 关键词： 延迟反馈 混沌控制 Hopf分支     

Effect of Weakly Transverse Perturbations on Dust Acoustic Solitary Waves with Adiabatic Variation of Dust Charge

By employing the reductive perturbation technique we derived a Kadomtsev-Petviashvili equation forunmagnetized dusty plasmas. It suggests that the nonlinear dust acoustic solitary waves with adiabatic variation of dustcharge are stable even there are some higher order transverse perturbatoins. There are only rarefactive solitary wavesfor this system which has been verified analytically in this paper.     

两亲性嵌段聚合物的同步辐射小角x射线散射研究

应用同步辐射小角x射线散射(SAXS)方法研究了不同聚合条件下苯乙烯对乙烯基苯甲酸两亲性嵌段聚合物的聚集行为,结果发现该聚合物在选择性溶液中自组装形成胶束.胶束的形态和结构取决于嵌段聚合物的组成、浓度以及溶剂的性质等因素 关键词： 小角x射线散射 两亲性嵌段聚合物 分形维数 粒径     

Investigation of laminar plasma remelting/cladding processing

Investigation of remelting and cladding processing with laminar plasma jets on several metals has been conducted looking for possible development of a new surface modification technique. The remelting tests illustrated that the new method could evidently improve the material microstructure and properties of cast iron. The cladding was done with Al₂O₃ ceramic powder on stainless steel. The energy dispersive spectra (EDS) analysis was used to determine the distribution of the major cladding element in the plasma-processed layers, for which the microstructure observations and hardness measurements were also performed.     

CP violation and extra dimensions

It is shown that new sources of CP violation can be generated in models with more than one extra dimension. In the supersymmetric models on the space-time , where the radius moduli have auxiliary vacuum expectation values and the supersymmetry breaking is mediated by the Kaluza–Klein states of the gauge supermultiplets, we analyze the gaugino masses and trilinear couplings for two scenarios and obtain the result that there exist relative CP violating phases among the gaugino masses and trilinear couplings. Received: 10 October 2001 / Published online: 20 December 2001     

氢氟烃/烷烃二元混合物的气液相平衡

整理了已公开发表的氢氟烃(HFC)/烷烃(HC)二元混合物气液相平衡实验数据,对实验数据进行了热力学一致性检验。采用PR方程加van der Waals混合规则描述该类混合物的气液相平衡性质,优化得到了11种混合物的二元交互作用系数,经比较表明采用优化结果能够高精度再现气液相平衡实验数据,比k_(ij)取0的计算结果有很大改善.     

关于消失平均振动的一个注记

本文得到了极大算子的几个不等式,并从这些结果推广了函数f∈L_(loc)~1(R,dx)属于VMO(R,dx)的一个必要条件。     

进口畸变条件下改善压气机性能的数值研究

依据"非定常两代流型"理论,验证了二维叶栅在均匀进气条件下,施加激励对其性能所起的改善作用,尔后重点研究了进口具有总压的周向畸变时,施加激励对其气动性能的影响。计算结果表明,在有无进口畸变时,施加一定的激励都会改善流场结构,气动参数有积极变化,压升和效率增加,特别是在流量比较小时,变化尤为明显.对于进口畸变和施加激励影响压气机性能的内在原因,从流场结构的变化方面进行了初步分析。