The intertropical convergence zone (ITCZ) can shift meridionally on seasonal and longer time scales. Previous studies have shown that the latitude of the ITCZ is negatively correlated with cross-equatorial atmospheric energy transport. For example, the ITCZ shifts southward as theNorthernHemisphere cools and the northward cross-equatorial energy transport strengthens in response. It has remaine...

PURPOSE Magnetic resonance imaging (MRI) was used to map the refractive index distribution in human eye lenses in vivo and to investigate changes with age and accommodation. METHODS Whole-eye MR images were obtained for sagittal and transverse axial planes in one eye each of 15 young (19-29 years) and 15 older (60-70 years) subjects when viewing a far ( approximately 6 m) target and at indivi...

We use two-dimensional hyperfine sublevel correlation (HYSCORE) spectroscopy to investigate the coordination geometry of the nitrogen ligands of biomimetic models of the oxygen-evolving complex of photosystem II. In the 2D HYSCORE spectroscopy study, [(bpy)2Mn(III)(μ-O)2Mn(IV)(bpy)2](ClO4)3 (bpy, 2,2'-bipyridine) (1) and [H2O(terpy)Mn(III)(μ-O)2Mn(IV)(terpy)OH2](NO3)3 (terpy = 2,2':6',2″-terpyr...

It is suggested from analysis of proton spin-spin coupling constants that the tetrahydropyrazine ring of 5methyltetrahydrofolate in solution is in a half-chair conformation, with the methyl group at N-5 and the methylene group C-9 truns, and with C-6-H in an equatorial position. The chemical shifts and spin-spin coupling constants for the carbon-bound hydrogens of (+)-L-, (-)-L, (+)-L-~-‘H, 7-‘...

Myopia is characterized by an increase in axial length of the eye, but the reasons for the axial elongation are still unknown. Higher intraocular pressure (IOP) has been associated with myopia and could be involved in eye enlargement. The purpose of this study was to investigate the effect of intraocular pressure on the geometry of the chick eye and to investigate whether an increase in IOP cou...

circularly-polarized antenna is built based on new SIW(substrate integrated waveguide)structure which contains cavity-backed resonator and a conventional polarized ring with twosquare slits in inner and outer ring that differ 90° at position and is proposed for right-handedcircular polarization (RHCP) and fabricated in two separate layers. A broadband impedancebandwidth of 13.9% and a RHCP axia...

in this paper, exact solution for two-plane transverse vibration analysis of axial-loaded multi-step timoshenko rotor carrying concentrated masses is presented. each attached element is considered to have both translational and rotational inertia. forward and backward frequencies and corresponding modes are obtained using transfer matrix method (tmm). the effect of the angular velocity of spin,...