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991.
Hiroyuki Naoi Denis M. Shaw Yoshiki Naoi Shiro Sakai George J. Collins 《Journal of Crystal Growth》2003,250(3-4):290-297
InAs was grown by low-pressure metalorganic chemical vapor deposition on vicinal GaAs(1 0 0) substrates misoriented by 2° toward [0 0 1]. We observed InAs crystal growth, at substrate temperatures down to 300°C, employing in situ plasma-generated arsine radicals as the arsenic source. The in situ generated arsine was produced by placing solid arsenic downstream of a microwave driven hydrogen plasma. Trimethylindium (TMIn) feedstock carried by hydrogen gas was used as the indium source. The Arrhenius plot of InAs growth rate vs. reciprocal substrate temperature displayed an activation energy of 46.1 kcal/mol in the temperature range of 300–350°C. This measured activation energy value is very close to the energy necessary to remove the first methyl radical from the TMIn molecule, which has never been reported in prior InAs growth to the best of authors’ knowledge. The film growth mechanism is discussed. The crystallinity, infrared spectrum, electrical properties and impurity levels of grown InAs are also presented. 相似文献
992.
Hisashi Kitagawa Naoki Tajima Hiroyuki Sagawa 《Zeitschrift für Physik A Hadrons and Nuclei》1997,358(4):381-387
Reaction cross sections and root-mean-square (rms) radii of A=17 and A=20 isobars are calculated by using a simplified Glauber model and spherical and deformed Hartree-Fock (HF) wave functions. The small separation energy effect is discussed on the reaction cross sections of A=17 isobars and possible proton halo in 17Ne by using modified spherical HF wave functions. The calculated rms mass radii of A=20 isobars are increased appreciably by the deformation effect and show a similar irregular pattern as a function of the isospin to that of the observed radii. 相似文献
993.
Hiroyuki Matsumoto 《Journal of Functional Analysis》2007,244(2):565-578
By using an explicit representation for the horizontal lift of the Brownian motion on the Poincaré upper half-plane H2, we show an expression for the heat kernel for the de Rham-Kodaira Laplacian on H2. We apply the result to a study on the Selberg trace formula. 相似文献
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997.
Photodarkening phenomena have been studied in glassy As2S3 films under pressure up to 3 kbar. A remarkable shift of the absorption edge to lower energy by the band gap illumination is observed under pressure. The shift is quenched even after releasing pressure. X-ray diffraction studies have also been performed at various pressures. The first sharp diffraction peak disappears at 50 kbar. The origin of the observed enhancement of the photodarkening may be associated with the increase in the interlayer correlation by application of pressure. 相似文献
998.
Yasumitsu Tamura Takayuki Yakura Jun-ichi Haruta Yasuyuki Kita 《Tetrahedron letters》1985,26(32):3837-3840
A short and efficient synthesis of dihydroxyacetone groups from keto groups involving the oxidation of ethynylcarbinol intermediates with [bis(trifluoroacetoxy) iodo] benzene (PIFA), is described. 相似文献
999.
Tsuyoshi Michinobu Norikatsu Sasao Hiroyuki Nishide 《Journal of polymer science. Part A, Polymer chemistry》2004,42(8):1912-1918
Modified poly(methacrylic acid) microparticles complexed with gadolinium(III) (Gd3+) ions were prepared in 100 nm. The emulsion terpolymerization of methacrylic acid, ethyl acrylate, and allyl methacrylate and the following complexation with Gd3+ ions yielded the polymer particles with different Gd3+ ion contents. Potentiometric titration of the complexation of the particle with Gd3+ ions indicated the formation of a very stable tris‐carboxylate coordinate complex with the Gd3+ ion. Electron spin resonance and IR spectra of the complexed particles were dependent on the Gd3+ ion content and the coordination environment in each particle. The microparticles dispersed on a mica substrate were subjected to atomic force microscopy (AFM), followed by magnetic force microscopy (MFM). AFM showed 100‐nm‐sized and monodispersed spherical images. The following MFM clearly provided strong magnetic responses exactly on the same particle positions, of which the images were also dependent on the Gd3+ ion content in the particle. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1912–1918, 2004 相似文献
1000.
To investigate the effect of cadmium on the accumulation of arsenic by Dunaliella sp., the arsenic accumulated in the alga was determined as a function of time for coexistence of the algae with arsenic and cadmium, with batch methodology. Growth of Dunaliella sp. was affected by addition of arsenic (Na2HAsO4.7H2O) and cadmium (CdCl.2.5H2O). Growth inhibition of Dunaliella sp. was accelerated by coexistence of arsenic and cadmium. The content of arsenic in Dunaliella sp. became a maximum at 15 h after exposure. The arsenic content in the cells was influenced by addition of cadmium to the solution; the arsenic content in the alga derived from growth in a 10 mg As dm ?3 solution decreased from 2.7 mg g?1 in the absence of cadmium to 0.35 mg g?1 for the addition of 100 mg Cd dm?3. Dunaliella sp. accumulated cadmium in large quantities but, in conditions of coexistence with arsenic and cadmium, the cadmium content in cells decreased with an increase in the concentration of arsenic in the growth medium Cadmium accumulation by Dunaliella sp. was observed in dead cells although arsenic accumulation was not observed. About 85% of arsenic in the cells was in the water-soluble fraction. On the other hand, about 42% of cadmium in the cells was in the water-soluble fraction, and about 55% was in a fraction soluble in cold trichloroacetic acid. 相似文献