E⊗eE\otimes e Jahn-Teller Effect in C703−C_{70}^{3-} Systems

The electron-phonon interaction in $C_{70}$ anions is studied by making use of a lattice relaxation approach. We find there exists a Jahn-Teller effect in $C_{70}^{3-}$ system, due to an extra electron being doped to the double degenerate $E_{1}^{''}$ state. As a result of this effect, the original $D_{5h}$ symmetry of the ground state becomes unstable, which causes distortion of the lattice configuration. The only symmetry maintained in the final state of the relaxation is the $x-y$ plane reflection symmetry. We further find that besides the Jahn-Teller active $A_{1}^{'}, A_{2}^{'}, E_{2}^{'}$ modes, the non-Jahn-Teller active $E_{1}^{'}$ vibrations also contribute to the relaxation process, which come from the nonlinear effect and are two or three orders smaller than those of the Jahn-Teller active modes. We suggest that the $C_{70}^{3-}$ molecule is a promising Berry Phase candidate in this effective $E \otimes e$ Jahn-Teller system.Comment: 14 pages, to appear in Mod. Phys. Lett. B (1997

Relationship between Perceived Social Support and Quality of Life among Kidney Transplant Recipients

Objective The aim of the study was to explore the relationship between perceived social support and quality of life (QOL) among recipients after kidney transplantation. Methods 210 kidney transplant recipients participated in this survey, and survey tools included the Multidimensional Scale of Perceived Social Support (MSPSS) and the Medical Outcomes Study 36-item Short Form (SF-36). Results The mean scores of kidney transplant recipients for MSPSS three sub-scales family support, friend support, and significant others support were 6.18±0.90, 5.48±1.32, 5.65±1.05 respectively, while MSPSS total scale score was 5.77±0.91. The mean scores for SF-36 Physical Component Summary (PCS) and Mental Component Summary (MCS) were 47.48±6.70, 48.40±9.65 respectively. Recipients’ PCS scores were correlated to significant others support sub-scale score and MSPSS total score significantly (P<0.05), while MCS scores were correlated to three sub-scales scales and total scale score (P<0.01). Conclusion Perceived social support of patients after kidney transplantation was significant related to their quality of life. The higher perceived social support was associated with the better quality of life

Multiplicative Updates for Nonnegative Quadratic Programming

Many problems in neural computation and statistical learning involve optimizations with nonnegativity constraints. In this article, we study convex problems in quadratic programming where the optimization is confined to an axis-aligned region in the nonnegative orthant. For these problems, we derive multiplicative updates that improve the value of the objective function at each iteration and converge monotonically to the global minimum. The updates have a simple closed form and do not involve any heuristics or free parameters that must be tuned to ensure convergence. Despite their simplicity, they differ strikingly in form from other multiplicative updates used in machine learning.We provide complete proofs of convergence for these updates and describe their application to problems in signal processing and pattern recognition

Elastic isotropy of hcp-Fe under Earth core conditions

Our first-principles calculations show that both the compressional and shear waves of hcp-Fe become elastically isotropic under the high temperatures of Earth inner core conditions, with the variation in sound velocities along different angles from the c axis within 1%. We computed the thermoelasticity at high pressures and temperatures from quasiharmonic linear response linear-muffin-tin-orbital calculations in the generalized-gradient approximation. The calculated anisotropic shape and magnitude in hcp-Fe at ambient temperature agree well with previous first-principles predictions, and the anisotropic effects show strong temperature dependences. This implies that other mechanisms, rather than the preferential alignment of the hcp-Fe crystal along the Earth rotation axis, account for the seismic P-wave travel time anomalies. Either the inner core is not hcp iron, and/or the seismologically observed anisotropy is caused by inhomogeneity, i.e. multiple phases.Comment: 16 pages, 3 figure

Free Boundary Minimal Surfaces in the Unit Three-Ball via Desingularization of the Critical Catenoid and the Equatorial Disk

We construct a new family of high genus examples of free boundary minimal surfaces in the Euclidean unit 3-ball by desingularizing the intersection of a coaxial pair of a critical catenoid and an equatorial disk. The surfaces are constructed by singular perturbation methods and have three boundary components. They are the free boundary analogue of the Costa-Hoffman-Meeks surfaces and the surfaces constructed by Kapouleas by desingularizing coaxial catenoids and planes. It is plausible that the minimal surfaces we constructed here are the same as the ones obtained recently by Ketover using the min-max method.Comment: 45 pages, 10 figure

Preparation and Characteristic of Dextran-BSA Antibody and Establishment of it’s Elisa Immunoassay

The enzyme linked immunosorbent assay (ELISA) is a potential tool for the determination of dextran. In this study, dextran–BSA antigens were prepared by Reductive amination method, and were confirmed by SDS-PAGE and free amino detection. The effects of coupled reaction conditions such as different oxidation degree of dextran, the reaction time were investigated and the immunity of the resulting dextran- BSA neoglycoprotein antigens were evaluated through the interaction with standard dextran antibody. The immunogen was immunized with white rabbits to obtained polyclonal antibody respectively. A general and broad class-specific Elisa detection method was developed according to Elisa theory. The method was put to use for quantitative analysis of dextran in practical saccharose samples