Quark model predictions for K∗K^* photoproduction on the proton

The photoproduction of $K^*$ vector mesons is investigated in a quark model with an effective Lagrangian. Including both baryon resonance excitations and {\it t}-channel exchanges, observables for the reactions $\gamma p\to K^{*0}\Sigma^+$ and $\gamma p\to K^{*+}\Sigma^0$ are predicted, using the SU(3)-flavor-blind assumption of non-perturbative QCD.Comment: Revtex, 3 eps figures, revised version accepted by PRC Rapid Comm

Organoaluminium complexes of ortho-, meta-, para-anisidines: synthesis, structural studies and ROP of ε-caprolactone (and rac-lactide)

Reaction of Me₃Al (two equivalents) with ortho-, meta- or para-anisidine, (OMe)(NH₂)C₆H₄, affords the complexes {[1,2-(OMe),NC₆H₄(μ-Me₂Al)](μ-Me₂Al)}₂ (1), [1,3-(Me₃AlOMe),NHC₆H₄(μ-Me₂Al)]2 (2) or [1,4-(Me₃AlOMe),NHC₆H₄(μ-Me₂Al)]₂ (3), respectively. The molecular structures of 1–3 have been determined and all three complexes were found to be highly active for the ring opening polymerization (ROP) of ε-caprolactone. 1 was found highly active either with or without benzyl alcohol present; at various temperatures, the activity order 1 > 2 ≈ 3 was observed. For the ROP of rac-lactide results for 1–3 were poor

Families of weighted sum formulas for multiple zeta values

Euler's sum formula and its multi-variable and weighted generalizations form a large class of the identities of multiple zeta values. In this paper we prove a family of identities involving Bernoulli numbers and apply them to obtain infinitely many weighted sum formulas for double zeta values and triple zeta values where the weight coefficients are given by symmetric polynomials. We give a general conjecture in arbitrary depth at the end of the paper.Comment: The conjecture at the end is reformulate

Driving Performances Assessment Based on Speed Variation Using Dedicated Route Truck GPS Data

It was hypothesized that a driver is not safe when travel speed is too high and also not necessarily safe when travel speed is too low. Based on this hypothesis, this paper studied the risky driving performances by measuring speed variations of a driver’s recurrent trips in two perspectives: 1) driver profiles, which scored the risk on-road driving of each driver and 2) driving patterns, which reflected the risk speed patterns of a type of drivers. The proposed method was tested on a 30-day global positioning system (GPS) dataset, collected from 100 trucks. The study first split the raw dataset into trips and finds the most repeatedly traveled route. Next, the frequency and amplitude of the speed variations from trips of each truck are calculated to establish driver profiles. A risk score is used to rank the truck drivers, i.e., a higher score indicates that the truck driver is more likely to conduct risky driving performances. All trucks are featured in four pre-defined driving patterns according to the different types of speed variations. The geospatial speed distribution of several trucks is manually examined from the raw dataset to verify the results. The contribution lies in providing a method to evaluate a driver’s risk performance through mass truck GPS data. The proposed method would help for monitoring on-road risky driving performances in large fleet management and also providing knowledge about driving styles among drivers which would be beneficial in study driver assistant system

Correlations among superconductivity, structural instability, and band filling in Nb1-xB2 at the critical point x=0.2

We performed an extensive investigation on the correlations among superconductivity, structural instability and band filling in Nb1-xB2 materials. Structural measurements reveal that a notable phase transformation occurs at x=0.2, corresponding to the Fermi level (EF) in the pseudogap with the minimum total density of states (DOS) as demonstrated by the first-principles calculations. Superconductivity in Nb1-xB2 generally becomes visible in the Nb-deficient materials with x=0.2. Electron energy-loss spectroscopy (EELS) measurements on B K-edge directly demonstrated the presence of a chemical shift arising from the structural transformation. Our systematical experimental results in combination with theoretical analysis suggest that the emergence of hole states in the sigma-bands plays an important role for understanding the superconductivity and structural transition in Nb1-xB2.Comment: 16 pages, 4 figure