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11.
Piotr H. Chankowski John Ellis Stefan Pokorski Martti Raidal Krzysztof Turzy
ski 《Nuclear Physics B》2004,690(3):279-301
We present predictions for flavour-violating charged-lepton decays induced by the seesaw mechanism implemented within the constrained minimal supersymmetric standard model (CMSSM) with universal input soft supersymmetry breaking terms. We assume that one heavy singlet neutrino almost decouples from the seesaw mechanism, as suggested by the pattern of light neutrino masses and mixing angles. This is suggested independently by sneutrino inflation with a low reheating temperature, TRH107 GeV, so as to avoid overproducing gravitinos. This requirement further fixes the mass of the weakly-coupled sneutrino, whose decays may lead to leptogenesis. We find that BR(μ→eγ)10−13 but BR(τ→μγ)10−9 in the bulk of the acceptable parameter space, apart from a few isolated points. The ratio BR(μ→eγ)/BR(τ→eγ) depends on only one complex parameter, and is particularly interesting to compare with experiment. 相似文献
12.
We study a lattice QCD mixed action with overlap valence quarks on two flavours of Wilson maximally twisted mass sea quarks. Employing three different matching conditions to relate both actions to each other, we investigate the continuum limit by using three values of the lattice spacing ranging from a≈0.05 fm to 0.08 fm. A particular emphasis is put on the effect on physical observables of the topological zero modes appearing in the valence overlap operator. We estimate the region of parameter space where the contribution from these zero modes is sufficiently small such that their effects can be safely controlled and a restoration of unitarity of the mixed action in the continuum limit is reached. 相似文献
13.
Krzysztof Okarma 《Optical Review》2012,19(5):349-354
In the paper the idea of the combined image quality metric based on the structural and feature similarity comparison is discussed. Since most of image quality assessment methods developed during last years require the nonlinear mapping to obtain high correlation with subjective quality scores, there is an important problem of choosing the proper mapping function and its optimal parameters in practical applications. The most common approach is the utilization of the logistic function but its parameters strongly depend on the specific image quality database. To avoid the necessity of such mapping the nonlinear combination of three known image quality metrics is proposed and verified for seven currently available image quality assessment databases in terms of the linear correlation with subjective scores. 相似文献
14.
Krzysztof?Idzik Jadwiga?So?oducho Mieczys?aw??apkowski Przemys?aw?Data 《Journal of fluorescence》2010,20(5):1069-1075
Novel light-emitting organic materials comprising conjugated oligomers chemically attached via a flexible spacer to an electron–or hole-conducting core were synthesized by Stille cross-coupling methodology and designed for tunable charge injection and optical properties. The hyperbranched structures
have been characterized by 1H NMR, 13C NMR, and UV-VIS spectroscopy. The obtained structures show good stability in common organic solvents such as CHCl3, toluene, and CH2Cl2 and exhibit excellent thermal stability. A preliminary electroluminescence properties were also investigated. This class
of materials will help to balance charge injection and transport and to spread out the charge recombination zone, thereby
significantly improving the device efficiency and lifetime of unpolarized and polarized OLEDs. 相似文献
15.
Krzysztof E. Krakowiak Guoping Xue Jerald S. Bradshaw N. Kent Dalley Alexander Y. Nazarenko Xian X. Zhang Reed M. Izatt 《Journal of heterocyclic chemistry》2000,37(4):719-723
A macrotricyclic ligand composed of two benzene rings connected by four 2,2′‐oxydiphenoxide bridges ( 2 ) has been prepared by treating 1,2,4,5‐tetrakis[2‐(2‐hydroxyphenoxy)phenoxymethyl]benzene with 1,2,4,5‐tetrakis(bromomethyl)benzene in acetonitrile in the presence of potassium carbonate. Ligand 2 is of interest because of its similarity to macrocycle 1 which interacts strongly with cesium ions. The proposed more direct route of treating an excess of 2,2′‐oxydiphenol with 1,2,4,5‐tetrakis(bromomethyl)benzene to prepare 2 did not give the desired macrocycle but gave bis(tribenzo‐11‐crown‐3) ( 8 ). An X‐ray crystal structure study of 2 showed that the benzene rings which are linked by the four 2,2′‐oxydiphenoxide bridges are connected in a nonsymmetric pattern. The structure of 8 was also determined using X‐ray diffraction methods, and is reported. 相似文献
16.
Zbigniew Ciunik Krzysztof Drabent Mikołaj F. Rudolf 《Journal of chemical crystallography》1994,24(8):507-510
The synthesis and crystal structure of 1,4-S,S-isothiosemicarbazidebutane dihydrobromide have been presented. The crystals are monoclinic:P21/n, a=7.9910(10),b=10.979(2),c=8.9240(10)Å, =111.450(10)°,Z=2, room temp. The structure was solved by direct methods. and refined to R=0.0297 for 846 reflections. The title compound consists of the centrosymmetric [C6H18N6S2]2+ dication and two Br– anions. Intramolecular N–H...N and intermolecular N–H...Br hydrogen bonds stabilizetrans conformation of the thiosemicarbazide moiety. 相似文献
17.
18.
The properties of an isothiocyanato liquid crystal compound (code name S1) has been studied with a view to compare its behavior with that of another member of its homologous series (code name S5). Optical properties, such as refractive index, polarisability, and their anisotropies, have been evaluated with varying temperature and the orientational order experimentally determined from the study of polarisability anisotropy and compared with theoretically computed values. Dielectric studies have been conducted to determine not only the dielectric anisotropy but also the effective molecular dipole moment and its temperature dependence. The temperature variation of the angle of inclination (β) of molecular dipole moment with the director direction has also been determined and compared with that of S5. In order to determine the nature of molecular association in the mesophase, the molecular correlation factor (g) has been estimated from the measurements of dipole moments of compound in solution and compared with the values obtained for S5. 相似文献
19.
20.
Maria Gdaniec Krzysztof Osmialowski Franciszek Saczewski 《Journal of chemical crystallography》1989,19(3):507-512
Crystal structure of the title compound belonging to the group of-acylimino derivatives of sulfur(II) compounds has been determined by X-ray structure analysis. The crystals are monoclinic, P21/c,a=11.210(2),b=8.197(1),c=13.659(2) Å,=102.36(2)°,V=1226.0(3) Å3,Z=4,D
x
=1.61 g cm–3, (MoK)=0.71069 Å,=6.3 cm–1. The structure has been refined to a finalR value of 0.035 for 1401 observed reflexions.The molecule is nearly planar with symmetrym. The title compound contains a very short intramolecular C=OS contact of 2.328(3) Å, suggesting a bond-non-bond resonance interaction. 相似文献