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341.
An electric field enhanced by a metallic nanoprobe has locally induced coherent anti-Stokes Raman scattering (CARS) of adenine molecules in a nanometric DNA network structure. Owing to the third-order nonlinearity, the excitation of the CARS polarization is extremely confined to the end of the tip apex, resulting in a spatial resolution far beyond the diffraction limit of light. Our tip-enhanced CARS microscope visualized the DNA network structure at a specific vibrational frequency (approximately 1337 cm(-1)) corresponding to the ring-breathing mode of diazole of adenine molecules. 相似文献
342.
Miyamoto N Kamei M Yoshitomi D Kanai T Sekikawa T Nakajima T Watanabe S 《Physical review letters》2004,93(8):083903
We have successfully observed two-photon above-threshold ionization in rare gas atoms (Ar, Xe, and He) by the fifth harmonic (25 eV photon energy) of a KrF laser. Use of the energy-resolved photoelectron counting system together with our laser, providing strong 25 eV radiation at 40-100 Hz, enabled us to detect the very weak single-color two-photon above-threshold ionization signals. Experimental data are in good agreement with our theoretical calculations newly developed along the line of multichannel quantum defect theory. 相似文献
343.
Pulse-front distortion as a result of broadband frequency doubling (BFD) has been compensated for over a 3-cm beam diameter by use of a telescope image relay system. As a result, distortion-free blue pulses with a peak power of 1.4 TW and a pulse width of 10 fs have been generated with a 10-Hz Ti:sapphire laser by use of this modified BFD configuration. 相似文献
344.
Blue pulses with durations of 8.5 fs are generated by broadband frequency doubling of subterawatt Ti:sapphire laser systems at 1-5-kHz repetition rates. The average powers are 1.6 W at 5 kHz and 1.9 W at 1 kHz. The peak power is 0.16 TW with a duration of 12 fs at 1 kHz. 相似文献
345.
Togashi T Kanai T Sekikawa T Watanabe S Chen C Zhang C Xu Z Wang J 《Optics letters》2003,28(4):254-256
We have demonstrated the second harmonic of a frequency-tripled Nd:YVO4 laser with 2.5-mW quasi-cw output by using an optically contacted, prism-coupled KBe2BO3F2 crystal. We also achieved the second harmonic with a frequency-doubled single-mode Ti:sapphire laser at 172.5 nm and sum-frequency mixing with a dual-wavelength Ti:sapphire laser at 163.3 nm. These wavelengths are to our knowledge the shortest obtained by use of nonlinear crystals for second-harmonic generation and sum-frequency mixing, respectively. 相似文献
346.
Taro Tsubomura Shigenobu Yano Sadao Yoshikawa Koshiro Toriumi Tasuku Ito 《Polyhedron》1983,2(2):123-124
347.
Tadakatsu Mandai Sadahiro Suzuki Atsushi Ikawa Taro Murakami Mikio Kawada Jiro Tsuji 《Tetrahedron letters》1991,32(52):7687-7688
A new synthetic method for polycyclic compounds via the palladium-catalyzed tandem carbonylation and intramolecular Diels-Alder reaction is described. 相似文献
348.
Isolation and structure of two metabolites of a macrolide antibiotic, SF-837 substance 总被引:1,自引:0,他引:1
S Inouye T Shomura T Tsuruoka S Omoto T Niida 《Chemical & pharmaceutical bulletin》1972,20(11):2366-2371
349.
Taro Nagao 《Journal of statistical physics》2007,129(5-6):1137-1158
It is well known that Pfaffian formulas for eigenvalue correlations are useful in the analysis of real and quaternion random matrices. Moreover the parametric correlations in the crossover to complex random matrices are evaluated in the forms of Pfaffians. In this article, we review the formulations and applications of Pfaffian formulas. For that purpose, we first present the general Pfaffian expressions in terms of the corresponding skew orthogonal polynomials. Then we clarify the relation to Eynard and Mehta’s determinant formula for hermitian matrix models and explain how the evaluation is simplified in the cases related to the classical orthogonal polynomials. Applications of Pfaffian formulas to random matrix theory and other fields are also mentioned. 相似文献
350.
Chatake T Shibayama N Park SY Kurihara K Tamada T Tanaka I Niimura N Kuroki R Morimoto Y 《Journal of the American Chemical Society》2007,129(48):14840-14841
The protonation states of buried histidine residues in human deoxyhemoglobin were unambiguously identified by using a neutron crystallographic technique. Unexpectedly, the neutron structure reveals that both the alpha- and beta-distal histidines (Hisalpha58 and Hisbeta63) adopt a positively charged, fully (doubly) protonated form, suggesting their contribution to the Bohr effect. In addition, the neutron data provide an accurate picture of the alpha1beta1 hydrogen-bonding network and allow us to observe unambiguously the nature of the intradimeric interactions at an atomic level. 相似文献