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961.
High resolution infrared spectra of He(N)-CO2 clusters with N up to 17 have been studied in the region of the CO2 nu(3) fundamental band. The B rotational constant initially drops as expected for a normal molecule, reaching a minimum for N=5. Its subsequent rise for N=6 to 11 can be interpreted as the transition from a normal (though floppy) molecule to a quantum solvation regime. For N>13, the B value becomes approximately constant with a value about 17% larger than that measured in much larger helium nanodroplets. Quantum Monte Carlo calculations of pure rotational spectra are in excellent agreement with the measured B in this size range and complement the experimental study with detailed structural information. For a larger cluster size (N=30-50) the simulations show a clear sign of convergence towards the nanodroplet B value. 相似文献
962.
963.
964.
The spectral properties of a diode-pumped Yb:Y2O3 ceramic laser are reported. We show experimentally that the instantaneous emission wavelengths of the laser change randomly with time, whereas its emission has fixed well-defined transverse modes. The central wavelength of the laser emission also shifts prominently with the increase of intracavity light intensity. It is found that the spectral properties of the laser can be explained well based on the strong reabsorption of light in the gain medium. 相似文献
965.
Synthesis and photocatalytic properties of highly crystalline and ordered mesoporous TiO2 thin films 总被引:1,自引:0,他引:1
Tang J Wu Y McFarland EW Stucky GD 《Chemical communications (Cambridge, England)》2004,(14):1670-1671
Highly crystalline and ordered mesoporous TiO2 thin films have been synthesized by stabilization of the mesostructure with confined carbon; the films exhibit 2.5% photoconversion efficiency for the water photolysis at zero-bias and Xe lamp illumination of 40 mW cm(-2). 相似文献
966.
Zhang Y Yu X Wang X Shan W Yang P Tang Y 《Chemical communications (Cambridge, England)》2004,(24):2882-2883
Metal-ion-immobilized zeolite nanoparticles have been applied for the first time to isolate phosphopeptides from tryptic beta-casein digest; the phosphopeptides enriched on the modified zeolite nanoparticles could be effectively identified by MALDI-TOF-MS/MS. 相似文献
967.
Zhong-Peng Yang Chong-guang Cao Xiao-Min Tang 《Journal of Applied Mathematics and Computing》2003,13(1-2):117-123
For ann x n real matrixX, let ?(X)=X ο (X ?1) T , where ο stands for the Hadamard (entrywise) product. SupposeA, B, C andD aren x n real nonsingular matrices, and among them there are at least one solutions to the equation ?(X)=1/nJ n . An equivalent condition which enable $M = \left( {\begin{array}{*{20}c} A & B \\ C & D \\ \end{array} } \right)$ become a real solution to the equation ?(X)=1/2nJ 2n , is given. As applications, we get new real solutions to the matrix equation ?(X)-1/2nJ 2n by applying the results of Zhang, Yang and Cao [SIAM. J. Matrix Anal. Appl, 21 (1999), pp: 642–645] and Chen [SIAM. J. Matrix Anal. Appl, 22 (2001), pp:965–970]. At the same time, all solutions of the matrix equation ?(X)=1/4J 4 are also given. 相似文献
968.
Hardy JC Iacob VE Sanchez-Vega M Neilson RG Azhari A Gagliardi CA Mayes VE Tang X Trache L Tribble RE 《Physical review letters》2003,91(8):082501
The half-life, 3.8755(12) s, and superallowed branching ratio, 0.5315(12), for 22Mg beta decay have been measured with high precision. The latter depended on gamma-ray intensities being measured with an HPGe detector calibrated for relative efficiencies to an unprecedented 0.15%. Previous precise measurements of 0+ --> 0+ transitions have been restricted to the nine that populate stable daughter nuclei. No more such cases exist, and any improvement in a critical Cabibbo-Kobayashi-Maskawa unitarity test must depend on precise measurements of more exotic nuclei. With this branching-ratio measurement, we show those to be possible for T(z)=-1 parents. We obtain a corrected Ft value of 3071(9) s, in good agreement with expectations. 相似文献
969.
Experimental observation of both anticipated and retarded synchronization is demonstrated using unidirectionally coupled semiconductor lasers with delayed optoelectronic feedback. Depending on the difference between the transmission time and the feedback delay time, the lasers fall into either the anticipated or the retarded synchronization regime, where the driven receiver laser leads or lags behind the driving transmitter laser. The two regimes are observed to have the same stability of chaos synchronization in the presence of small perturbations by noise and parameter mismatches. In both regimes the observed time shift between the synchronized chaotic waveforms is found to be equal to the difference between the transmission time and the feedback delay time. 相似文献
970.
Moresco F Gross L Alemani M Rieder KH Tang H Gourdon A Joachim C 《Physical review letters》2003,91(3):036601
A crucial problem in molecular electronics is the control of the electronic contact between a molecule and its electrodes. As a model system, we investigated the contact between the molecular wire group of a C90H98 (Lander) molecule and the edge of a Cu(111) monatomic step. The reproducible contact and decontact of the wire was obtained by manipulating the Lander with a low temperature scanning tunneling microscope. The electronic standing wave patterns on the Cu(111) surface serve to monitor the local electronic perturbation caused by the interaction of the wire end with the step edge, giving information on the quality of the contact. 相似文献