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排序方式: 共有489条查询结果,搜索用时 46 毫秒
41.
Padmanaban M Müller P Lieder C Gedrich K Grünker R Bon V Senkovska I Baumgärtner S Opelt S Paasch S Brunner E Glorius F Klemm E Kaskel S 《Chemical communications (Cambridge, England)》2011,47(44):12089-12091
A modular approach for the synthesis of highly ordered porous and chiral auxiliary (Evans auxiliary) decorated metal-organic frameworks is developed. Our synthesis strategy, which uses known porous structures as model materials for incorporation of chirality via linker modification, can provide access to a wide range of porous materials suitable for enantioselective separation and catalysis. Chiral analogues of UMCM-1 have been synthesized and investigated for the enantioseparation of chiral compounds in the liquid phase and first promising results are reported. 相似文献
42.
Volodymyr M. Prokip 《Journal of Mathematical Sciences》2011,174(4):481-485
The necessary and sufficient conditions of diagonalization of matrices over a domain of principal ideals with minimal polynomial m(??) = (?? ? ??)(?? ? ??), ?? ?? ?? are obtained. On the basis of the obtained results, the conditions under which the matrices have common eigenvectors are indicated. 相似文献
43.
Grygoriy Dmytriv Helmut Ehrenberg Volodymyr Pavlyuk 《Journal of solid state chemistry》2005,178(9):2825-2831
The remarkably broad homogeneity range of the NaTl-type Zintl phase in the ternary phase diagram Li-In-Ag at room temperature was determined by structure evaluation using X-ray powder diffraction. The colours of the investigated Zintl phases correlate with the valence electron concentration (VEC) as already established for the quasibinary cut Li0.5(InxAg1−x)0.5 with 0.47?x?1.00, i.e. with decreasing VECs the colour changes from grey over reddish to bright yellow. All compounds in the new quasibinary cut Lix(In0.5Ag0.5)1−x with 0.47?x?0.60 appear free from vacancies in the Li-sublattice, even for Li-deficient compositions. The partial occupation of Li-sites by excess Ag and In instead is in full agreement with the behaviour of the binary NaTl-type Zintl phases LixZn1−x and LixCd1−x (0.47?x?0.54) with a low VEC about 1.5. 相似文献
44.
We study bounded and unbounded *-representations of Twisted Generalized Weyl Algebras and algebras similar to them for different choices of involutions. 相似文献
45.
\noindent We describe the asymptotic behavior of the cardinalities of
the finite symmetric inverse semigroup ISn and its endomorphism
semigroup. This is applied to show that the ratio
|ISn|/|End(ISn)| is asymptotically 0, answering a
question of Schein and Teclezghi. We also apply our results to compute
the distributions of elements from ISn with respect to certain
combinatorial properties, and to compute the generating functions
for |ISn| and for the number of nilpotent elements in ISn. 相似文献
46.
Using a combination of ab initio and semiempirical methods, adsorption problems on surfaces with large unit cells and low symmetry can still be studied. Here, a hybrid approach of density functional theory (DFT) and Hartree-Fock (HF) was used. As an example, we determined the geometry and the electronic properties of benzoic acid (BA), salicylic acid (SA) and para-salicylic acid (p-SA) adsorbed on MgSO(4).H(2)O (100), which are used as conditioner molecules for the electrostatic separation of minerals. Contrary to general expectations, these molecules are chemisorbed, with binding energies around 1.9 eV, forming bonds through the carboxylic O atom of the COOH groups in a nonplanar geometry, although the surface is a stoichiometric wide-band-gap insulator and the molecules stay intact. In contrast, a planar adsorption geometry turned out to be nonbonding. Bonding takes place by means of surface-molecule resonances due to the overlap of the valence band with molecular orbitals, assisted by a small charge-transfer molecule to the surface of around 0.15e. These combined interactions cause an intramolecular twist between the COOH group and the benzene ring. 相似文献
47.
Sergio Albeverio Alexei Konstantinov Volodymyr Koshmanenko 《Integral Equations and Operator Theory》2005,52(4):455-464
The decomposition theory for the singular continuous spectrum of rank one singular perturbations is studied. A generalization of the well-known Aronszajn-Donoghue theory to the case of decompositions with respect to α-dimensional Hausdorff measures is given and a characterization of the supports of the α-singular, α-absolutely continuous, and strongly α-continuous parts of the spectral measure of
- class rank one singular perturbations is given in terms of the limiting behaviour of the regularized Borel transform. 相似文献
48.
Volodymyr M. Gorkavenko Stanislav I. Vilchynskiy 《The European Physical Journal C - Particles and Fields》2010,70(4):1091-1098
The equations connecting elements of the Yukawa matrix to elements of the active neutrino mass matrix in the νMSM theory (an extension of the Standard Model by a singlet of three right-handed neutrinos) was analyzed, and explicit relations
for the ratio of the Yukawa matrix elements and elements of the active neutrino mass matrix were obtained. This relation can
be used for getting more accurate constraints on the model parameters. Particularly, with the help of the obtained results
we investigated CP-violating phase in the νMSM theory. We demonstrate that even in the case when elements of the active neutrino mass matrix are real the baryon asymmetry
can be generated also. 相似文献
49.
Nahirnyak VM Yoon SW Holland CK 《The Journal of the Acoustical Society of America》2006,119(6):3766-3772
The efficacy of ultrasound-assisted thrombolysis as an adjunct treatment of ischemic stroke is being widely investigated. To determine the role of ultrasound hyperthermia in the process of blood clot disruption, the acousto-mechanical and thermal properties of clotted blood were measured in vitro, namely, density, speed of sound, frequency-dependent attenuation, specific heat, and thermal conductivity. The amplitude coefficient of attenuation of the clots was determined for 120 kHz, 1.0 MHz, and 3.5 MHz ultrasound at room temperature (20 +/- 2 degrees C). The attenuation coefficient ranged from 0.10 to 0.30 Np/cm in porcine clots and from 0.09 to 0.23 Np/cm in human clots. The experimentally determined values of specific heat and thermal conductivity for porcine clotted blood are (3.2 +/- 0.5) x 10(3) J/kg x K and 0.55 +/- 0.13 W/m x K, respectively, and for human clotted blood are (3.5 +/- 0.8) x 10(3) J/kg x K and 0.59 +/- 0.11 W/m x K, respectively. Measurements of the acousto-mechanical and thermal properties of clotted blood can be helpful in theoretical modeling of ultrasound hyperthermia in ultrasound-assisted thrombolysis and other high-intensity focused ultrasound applications. 相似文献
50.
We introduce a twisted higher rank generalization of generalized Weyl algebras and study simple weight modules over such algebras. 相似文献