In-situ observations of dissolution process of GaSb into InSb melt by X-ray penetration method

Dissolution process of GaSb into InSb melt was observed by an X-ray penetration method. The intensity of X-rays penetrated through the rectangular shaped GaSb (seed)/InSb/GaSb (feed) sandwich sample was recorded by the CdTe line sensor detector. The penetrated X-ray intensities and images of the sample were obtained as a function of time and temperature. The gallium (Ga) composition profile of the sample was calculated as a function of time by making the calibration line with the penetrated X-ray intensities of GaSb and InSb standard samples. The calculated Ga composition profile of the grown sample agreed well with the data measured by energy dispersive X-ray spectroscopy analysis. The result suggested that lower GaSb seed dissolved faster than upper GaSb feed despite of the low temperature at the lower GaSb seed. It clearly indicates that the solutal transport induced by gravity strongly affects the dissolution process.     

Analytic smoothing effect for global solutions to nonlinear Schrödinger equations

We prove the global existence of analytic solutions to the Cauchy problem for the cubic Schrödinger equation in space dimension n?3 for sufficiently small data with exponential decay at infinity. Minimal regularity assumption regarding scaling invariance is imposed on the Cauchy data.     

17C反应截面测量及有限力程Glauber模型分析

用透射法测量了能量为79AMeV的¹⁷C在¹²C反应靶上的反应截面;利用有限力程Glauber模型对¹⁷C的密度分布进行了分析.由高能区(965AMeV)相互作用截面数据分析认为¹⁷C具有谐振子密度分布,但拟合本实验结果及高能区实验数据发现,¹⁷C的中子密度分布中存在一个尾巴;假设¹⁷C密度为芯核加单粒子密度分布形式,分析认为¹⁷C的价中子主要处于1d5/2?轨道.     

Tungsten microcone arrays grown using nanosecond pulsed-Nd:YAG laser in a low-pressure He-gas atmosphere

Tungsten microcone arrays with a high aspect ratio are formed by the cumulative nanosecond pulsed-Nd:YAG laser irradiation of single-crystal tungsten under low pressure in an inert atmosphere. The morphology of the microcones and their density were strongly affected by the number of laser pulses. The microcones grew to a length of 20 μm with a diameter of about 1.5 μm at the tip after irradiation with more than 1200 pulses under our experimental conditions. They may have potential applications for emission cathodes in a field-emission display (FED) and in microelectronic devices. Received: 8 January 2001 / Accepted: 13 June 2001 / Published online: 2 October 2001     

Time-dependent quadrupole interactions for <Superscript>140</Superscript>Ce ions implanted in highly oriented pyrolytic graphite

The time-differential perturbed angular correlation (TDPAC) method was applied to a study on the behavior of ¹⁴⁰Ce atoms implanted in highly oriented pyrolytic graphite (HOPG). Exponential-type gradual attenuation of the directional anisotropy of the relevant γ-ray cascade was observed in the perturbation patterns. From temperature dependence of the relaxation rate, a thermally activated dynamic motion of the probe atoms was suggested.     

Electromagnetic moments of the doubly closed shell ±1 nucleon nuclei and on-line nuclear polarization

Electromagnetic moments of doubly closed shell ±1 nucleon nuclei were studied. Recent technical developments of the β-NMR was shown that was applicable for the polarized β emitters. Also, the implication of those new moments were discussed especially on the nuclear interactions and non nucleonic degrees of freedom.     

Dehydrogenative Diels-Alder reaction

The dehydrogenative cycloaddition of dieneynes, which possess a diene in the form of a styrene moiety and a dienophile in the form of an alkyne moiety, produces naphthalene derivatives when heated. It was found that a key requirement of this process is the presence of a silyl group attached to the alkyne moiety, which forces a dehydrogenation reaction to occur.     

H(x)TeV9O28]((5-x)-) (x=1 and 2): vanadotellurates with decavanadate structure

Two new vanadotellurates, [HTeV(9)O(28)](4-) and [H(2)TeV(9)O(28)](3-) have been synthesized and structurally characterized as tetra-n-butylammonium (TBA) salts: TBA(4)[HTeV(9)O(28)]·2CH(3)CN [triclinic, space group P ?1, a = 16.7102(6) ?, b = 17.4680(7) ?, c = 17.9634(7) ?, α = 74.412(1)°, β = 67.494(1)°, γ = 74.160(2)°, Z = 2] and TBA(3)[H(2)TeV(9)O(28)] [monoclinic, space group P2(1)/c, a = 13.0013(5) ?, b = 19.157(1) ?, c = 28.453(1) ?, β = 97.222(2)°, Z = 4]. The results of the structural analyses indicate that the four O atoms that bridge two V atoms on the Te side are the most basic ones in the structure. The results of density-functional theory (DFT) calculations support this view.     

Development of Small Drop-Weight Testing Machine Based on Electromagnetic Induction

Experimental Mechanics - The impact strengths of solder joints between an electrical substrate and millimeter- or micrometer-sized electrical components such as resistors and capacitors must be...