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991.
M. Watanabe A. Endoh N. Sarukura S. Watanabe 《Applied physics. B, Lasers and optics》1989,48(5):417-420
A 180-fs UV pulse has been generated based on a hybrid synchronously pumped mode-locked dye laser for a multiterawatt KrF laser system. The pulse width was measured by the single shot autocorrelation technique with the three-photon fluorescence of the XeF C-A transition. The pulse width broadening due to dispersive media was investigated. The results show that the observed pulse width broadening from 210 fs to 390 fs through the entire system is explained mostly by the linear dispersion of the optical elements for near-transform-limited input pulses. 相似文献
992.
H. Imajo K. Hayasaka R. Ohmukai M. Watanabe S. Urabe 《Applied physics. B, Lasers and optics》1995,61(3):285-289
Be+ ions trapped in a Penning trap are laser-cooled to about 10 mK. The excitation spectra of ion clouds containing about 500 ions are obtained by scanning the frequency of the cooling laser and discontinuities in these spectra are observed because of phase transitions. When the cooled ions are heated electrically by applying an rf voltage, no phase transition occurs and the spectra become continuous. Two-dimensional measurement of the ion clouds is carried out and the abrupt change in the shape of the ion cloud due to the phase transition is observed. When many ions are trapped and cooled, the phase transition occurs partially and a transient state where two states are mixed can be observed. The static properties of the ions are also measured by using an additional probe laser and the results of experimental measurements are compared with theoretical predictions. 相似文献
993.
N Watanabe M Asano K Yamamoto T Nagatsu T Matsumoto K Fujita 《Biomedical chromatography : BMC》1989,3(5):187-191
A novel analytical method for biological polyamines (putrescine, spermidine and spermine) was developed. Polyamines were separated by ion-pair reversed phase chromatography using a polymer-based octadecyl bonded column. A polyamine oxidase immobilized column worked effectively as a post-column reactor to convert polyamines to hydrogen peroxide which was eventually detected by electrochemical oxidation on platinum electrode. This method required neither tedious derivatization nor gradient elution, permitting us to perform simple and rapid analysis of polyamines. The detection limits were 0.3, 0.6, and 4 pmol injected for putrescine, spermidine, and spermine, respectively with a linear range of two to three orders of magnitude. Chromatograms obtained with samples from human urine and rat brain homogenates demonstrated the high sensitivity and selectivity of the method. 相似文献
994.
Minoru Nagata Naoto Tsutsumi Tsuyoshi Kiyotsukuri 《Journal of polymer science. Part A, Polymer chemistry》1988,26(1):235-245
Aromatic polyamides were prepared from systematically halogenated terephthalic acids with hexamethylene diamine, piperazine, 4,4′-diaminodiphenylether and p-phenylene diamine by interfacial or low temperature solution polycondensation. The halogenated terephthalic acids used have mono-, di-, or tetra-substituted fluorine, chlorine, or bromine atoms on the benzene ring. The nonhalogenated terephthalic acid was also used for the comparison. The effects of halogen substitution on the benzene ring on the synthesis and some properties of polymers were examined. Reduced specific viscosity decreased in the order F > Cl > Br by halogen substitution. The incorporation of halogen substituents on the ring led to a decrease of crystallinity and fluoro-substituents hindered the crystallization more strongly. The melting point (Tm) decreased in the order F > Cl > Br by mono-substitution, and Br > Cl > F by di-and tetra-substitution. The change of Tm caused by the difference of the number of halogen substituents differed depending on the rigidity of polymer chains. The flame-retardancy estimated by thermogravimetry, self-ignition, and flash-ignition test increased with increasing halogen content of the polymers. Solubility increased remarkably by halogen substitution. The peak temperature of tan δ decreased by halogen substitution. Some discussion was made on these effects of halogen substitution. 相似文献
995.
Tsuyoshi Kobayashi 《Topology and its Applications》1985,20(1):67-78
In this paper we consider a non-singular Morse-Smale flow Φt on an irreducible, simple, closed, orientable 3-manifold M. We define a primitive flow ψt from Φt, and call the link type of the closed orbits of ψt a primitive link of Φt. We show that the link types of the primitive links are finite and every non-singular Morse-Smale flow on M is obtained from a primitive flow by exchanging the flow in a regular neighborhood of attracting or repelling closed orbits. 相似文献
996.
A. Sagisaka Y. Nabekawa K. Kondo S. Watanabe 《Applied physics. B, Lasers and optics》1997,65(4-5):475-480
Received: 10 January 1997 相似文献
997.
N. Aoi K. Yoneda H. Miyatake H. Ogawa Y. Yamamoto E. Ideguchi T. Kishida T. Nakamura M. Notani H. Sakurai T. Teranishi H. Wu S. S. Yamamoto Y. Watanabe A. Yoshida M. Ishihara 《Zeitschrift für Physik A Hadrons and Nuclei》1997,358(2):253-255
Experimental studies of β-decay measurements of the neutron drip line nuclei 11Li and 14Be are presented. β- decay schemes of these nuclei are determined by measuring β-rays, delayed neutrons and γ-rays in triple coincidence. The decay schemes of both 11Li and 14Be associated with single neutron emission are unambiguously determined. New levels in their daughter nuclei, 11Be and 14B, are found. In addition, the deduced level scheme of 14B indicates the lowering of 2s 1/2 single neutron orbital with respect to 1p 1/2 orbital in the N=9 isotones. Such behavior is known to exist in N=7. 相似文献
998.
E. Pelucchi S. Watanabe K. Leifer B. Dwir E. Kapon 《Physica E: Low-dimensional Systems and Nanostructures》2004,23(3-4):476
We report on the growth and optical properties of various configurations of sub-micron pitch dense arrays of pyramidal quantum dots (QDs) grown by organometallic chemical vapour deposition on patterned substrates. We show that the effective growth rate of these QDs is influenced by the ratio between the free {1 1 1}B area and {1 1 1}A exposed facets surrounding them. This provides a powerful technique for engineering the energy level structure of ordered QD arrays by means of geometrical patterning of the growth template. Such technique should be particularly useful for applications in photonic crystals incorporating QDs with tailored absorption and/or emission properties. 相似文献
999.
The magnetic and transport properties of a new cubic KSbO3-type ruthenate, (Ba1−xSrx)2Ru3O9 (x≈0.35), have been investigated. The crystal structure has a singular geometry in which ruthenium atoms form an ideal three-dimensional orthogonal dimer lattice. The magnetic susceptibility is Pauli-paramagnetic but exhibits an anomalous temperature dependence reminiscent of a gap-like behavior. The resistivity exhibits a metallic behavior, except for a rise at low temperature. 相似文献
1000.
We have developed a new electron energy analyzer with a large solid angle of 0.14π, which is comparable to that of cylindrical mirror analyzer. Typical energy resolution was ΔE/E0 ∼ 0.016 for the aperture of 1 mm and central radius of 100 mm, and typical angular resolution was less than 0.5°. 相似文献