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41.
42.
Russian Journal of Organic Chemistry - 相似文献
43.
M. K. Kovalev K. P. Mogil’nikov O. I. Semenova V. N. Kruchinin M. S. Mel’gunov 《Bulletin of the Lebedev Physics Institute》2009,36(12):365-366
The sensitivity of chemical sensors depends on the number of receptors on the surface; hence, an important role is played
by the accessible support surface. Films based on silica mesoporous mesophase materials feature the highest specific surface
area for silica materials, and their walls can be modified by various functional groups. In this paper, we propose to use
mesoporous mesophase films as supports of sensitive elements for Cr3+ ions. 相似文献
44.
Anokhina P. V. Romanova T. V. Mel’nikova S. F. Tselinskii I. V. 《Russian Journal of Organic Chemistry》2011,47(10):1606-1607
Russian Journal of Organic Chemistry - 相似文献
45.
The reaction of 2-amino-2-(trichloromethyl)tetrahydro-4-pyrone-5-spirocyclohexane with ethylenediamine afforded 6-amino-2,3-dihydro-4-pyrone-3-spirocyclohexane, whereas 2-amino-5,5-dimethyl-2-(trichloromethyl)tetrahydro-4-pyrone gave 2-(3-hydroxy-2,2-dimethylpropionylmethylene)imidazolidine in low yield. 相似文献
46.
Photoluminescence excitation spectroscopy and scanning-tunneling spectroscopy are used to study the electronic states in CdSe quantum rods that manifest a transition from a zero-dimensional to a one-dimensional quantum-confined structure. Both optical and tunneling spectra show that the level structure depends primarily on the diameter of the rod and not its length. With increasing diameter, the band gap and the excited state level spacings shift to the red. The level structure was assigned using a multiband effective-mass model, showing a similar dependence on rod dimensions. 相似文献
47.
For the purpose of improving present approximations to the exchange and correlation potentials, newly derived properties of the exact exchange and correlation potentials are summarized. Present approximations are not expected to generally satisfy these properties. The summarized properties include relations at the Fermi level, low-density requirements, and a new density functional formula for computing ionization energies. © 1995 John Wiley & Sons, Inc. 相似文献
48.
49.
V. E. Egorushkin S. E. Kul’kova N. V. Mel’nikova A. N. Ponomarev 《Journal of Experimental and Theoretical Physics》2005,101(2):350-356
The dissociation of a gas molecule and the formation of a new chemical bond upon adsorption of this molecule on the surface of a transition metal are studied using the method of equations of motion. It is shown that both processes involve the formation of a mixed intermediate state during the adsorbate-substrate interaction. The dissociation is caused by a resonance growth of the vibrational mode, whereby the dissociation barrier is determined by the hybridization energy and by the frequency of electron transitions between molecular levels and the d electron energy levels of the metal in the mixed intermediate state. The resonance conditions for the formation of new surface structures are established. 相似文献
50.
Graff BA Benjaminsen IC Melås EA Brurberg KG Rofstad EK 《Magnetic resonance imaging》2005,23(9):961-966
The purpose of this study was to use dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to search for systematic intratumor heterogeneity in blood perfusion in human melanoma xenografts growing intradermally in BALB/c-nu/nu mice. Six xenografted tumors of an amelanotic human melanoma line (A-07) were included in the study. DCE-MRI was performed daily for 5 days by using spoiled-gradient recalled sequences. Tumor images of E.F (E is initial extraction fraction and F is perfusion) were produced by subjecting DCE-MRI data to Kety analysis. E.F was used as a measure of tumor blood perfusion, since comparative studies have shown that E.F is closely related to blood perfusion in A-07 tumors. The E.F images indicated that the intratumor heterogeneity in blood perfusion was similar in all investigated tumors. The blood perfusion was low in the center of the tumors and increased toward the tumor periphery in the dorsal and ventral direction by a factor of 3-4, but not in the lateral and medial direction. The magnitude of the heterogeneity increased by a factor of approximately 2 during tumor growth. In conclusion, intradermal human melanoma xenografts show significant systematic intratumor heterogeneity in blood perfusion. 相似文献