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2009年05月22日

【期刊论文】Structure Similarity of Mixed Buoyancy-Thermocapillary Flow in Half-Zone Liquid Bridge

曾忠， Zhong Zeng， *， Hiroshi Mizuseki， Kazuyuki Higashino， Kiyoshi Shimamura， Tsuguo Fukuda and Yoshiyuki Kawazoe

Materials Transactions, Vol. 42, No.11 (2001) pp. 2322 to 2331，-0001，（）：

-1年11月30日

The mixed buoyancy-thermocapillary flow in a half-zone liquid bridge with the dynamic Bond number Bd≈α(1) is investigated numerically by the finite volume method. The similarities of temperature and velocity structures are realized under conditions of fixed Marangoni and Rayleigh numbers in steady two-dimensional regime for a suitable Prandtl number range.

thermocapillary convection,， Marangoni convection,， floating zone,， half-zone,， buoyancy,， similarity,， nature convection

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2009年05月22日

【期刊论文】CAN 5d TRANSITION-METAL MONOLAYERS BE MAGNETIC ON FERROMAGNETIC SUBSTRATE?

曾忠， Q. Sun， a， b Q. Wang， a J.Z. Yu， a z. Zen， a Z.Q. Li， a K. Ohnoa and Y. Kawazoea

Solid State Communications, Vol. 106, No.10, pp. 665-667, 1998，-0001，（）：

-1年11月30日

摘要

The magnetic properties of X/5Fe/X (X: Hf, Ta, W, Re, Os, Ir, Pt) have been studied by means of the full-potential linearized augmented-plane-wave method, in which the core states are treated fully relativistically and the valence states are treated semirelativistically and the generalized gradient approximations' (GCA) exchange-correlation potentials are employed for 5d elements. It has been found that Hf, Ta, W, Re and Os overlayers on Fe(0 0 1) are almost nonmagnetic. Following this trend, if the spin-orbit interactions are taken into account, the magnetism of Ir and Pt overlayers is expected to be killed as for the Ag(0 0 1) and Au(0 0 1) substrate. So the nonexistence of the magnetism for 5d overlayers is furtherly verified on ferromagnetic substrate besides on nonmagnetic substrate. Moreover, due to the more extended 5d orbitals as compared to those of 3d and 4d, much stronger hybridizations between the 5d states of the overlayer and the Fe substrate exist, which greatly suppress the magnetic moment of the interface Fe layer.

A.， magnetic films and multilayers,， A.， surfaces and interfaces.，

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2009年05月22日

【期刊论文】Size effect on quasibound states and negative differential resistances in step-barrier structures

曾忠， Yong Guo a， b， )， Bing-Lin Gu a， Zhong Zeng b， Yoshiyuki Kawazoe b

Physics Letters A 261(1999)114-118，-0001，（）：

-1年11月30日

摘要

Electronic states and tunneling properties in step-barrier structures have been investigated. The results indicate that there exists quasibound states in step-barrier structure both at zero bias and under an applied bias. Size effect on negative-differential resistances is examined and the condition for obtaining larger current peak-to-valley ratios has been discussed.

Heterojunctions， Resonant tunneling， Quasibound states， Negative-differential resistance

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2009年05月22日

【期刊论文】Usefulness of experiments with model fluid for thermocapillary convectionFeffect of Prandtl number on two-dimensional thermocapillary convection

曾忠， Zhong Zenga， *， Hiroshi Mizusekia， Kiyoshi Shimamuraa， Tsuguo Fukudaa， Yoshiyuki Kawazoea， Kazuyuki Higashinob

Journal of Crystal Growth 234(2002)272-278，-0001，（）：

-1年11月30日

摘要

The floating zone technique is promising to realize large, high-quality crystals under microgravity. Thermocapillary flow, which is the dominant convection in a floating zone under microgravity, has been widely reported in the literature to be extremely sensitive to the Prandtl number Pr: In the present study, the effect of Pr on steady thermocapillary convection is re-evaluated based on both analytical and numerical solutions. The results indicate that an approximate similarity of temperature and velocity structures in a large Pr range is realized under suitable conditions, fixing the Marangoni number Ma; in steady two-dimensional regime.

A1.， Computer simulation， A1.， Fluid flow， A1.， Heat transfer， A1.， Marangoni convection， A1.， Thermocapillary convection， A2.， Floating zone technique

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2009年05月22日

【期刊论文】The local magnetism of Fe impurity in Nbn and NbnMom clusters

曾忠， Q. Wanga， b， Q. Suna， *， J.Z. Yub， Z. Zengb， Y. Kawazoeb

Journal of Magnetism and Magnetic Materials 184(1998)106-110，-0001，（）：

-1年11月30日

摘要

The local magnetic properties of impurity Fe in small Nbn and NbnMom clusters have been studied by using a linear combination of atomic orbitals approach with the density functional formalism, and the Kohn

Impurity effect， Local spin-density functional approximation， Cluster

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