Two-Photon Spectroscopy of Acetylene - Photodissociation Processes at 9-10 eV Energy Levels

The gerade states of acetylene at 9-10 eV have been studied by monitoring the C₂ emission. Larger Δv₂ excitations are seen than previously reported by Ashfold et al. The observed two-photon resonant levels show extensive predissociation. Experimental evidence from the two-color photofragment excitation measurement is given to support the conclusion that the excited-state ethynyl radical and atomic hydrogen are the corresponding predissociation products. Most C₂ emissions seen in this work are due to the subsequent photodissociation of the intermediate C₂H to C₂ (d³Π_g).     

Mixed integer programming models for dispatching vehicles at a container terminal

This paper presents scheduling models for dispatching vehicles to accomplish a sequence of container jobs at the container terminal, in which the starting times as well as the order of vehicles for carrying out these jobs need to be determined. To deal with this scheduling problem, three mixed 0–1 integer programming models, Model I, Model II and Model III are provided. We present interesting techniques to reformulate the two mixed integer programming models, Model I and Model II, as pure 0–1 integer programming problems with simple constraint sets and present a lower bound for the optimal value of Model I. Model III is a complicated mixed integer programming model because it involves a set of non-smooth constraints, but it can be proved that its solutions may be obtained by the so-called greedy algorithm. We present numerical results showing that Model III is the best among these three models and the greedy algorithm is capable of solving large scale problems.     

Pricing American Asian options with higher moments in the underlying distribution

We develop a modified Edgeworth binomial model with higher moment consideration for pricing American Asian options. With lognormal underlying distribution for benchmark comparison, our algorithm is as precise as that of Chalasani et al. [P. Chalasani, S. Jha, F. Egriboyun, A. Varikooty, A refined binomial lattice for pricing American Asian options, Rev. Derivatives Res. 3 (1) (1999) 85–105] if the number of the time steps increases. If the underlying distribution displays negative skewness and leptokurtosis as often observed for stock index returns, our estimates can work better than those in Chalasani et al. [P. Chalasani, S. Jha, F. Egriboyun, A. Varikooty, A refined binomial lattice for pricing American Asian options, Rev. Derivatives Res. 3 (1) (1999) 85–105] and are very similar to the benchmarks in Hull and White [J. Hull, A. White, Efficient procedures for valuing European and American path-dependent options, J. Derivatives 1 (Fall) (1993) 21–31]. The numerical analysis shows that our modified Edgeworth binomial model can value American Asian options with greater accuracy and speed given higher moments in their underlying distribution.     

广义Stirling数偶的理论及应用

The object of this expository paper is to sum up several results concerning generalized Stirling number (GSN) pairs investigated earlier by the author. Also expounded in some detail are two kinds of extended GSN pairs with applications (illustrative examples).     

Reflection type heterodyne grating interferometry for in-plane displacement measurement

A novel method is presented for one-dimensional (1-D) and two-dimensional (2-D) in-plane displacements measurement that is based on the heterodyne grating interferometry. The novel setup of the optical configuration reduces the airstreams disturbance and maintains the environmental vibration at minimum level, allowing high stability and low measurement error to be achieved. Resulting from the theoretical calculation, our method can be sensitive to the sub-picometer level. With highly controlled isolation system, the low frequency noise can be reduced to minimum level, and only high frequency noises are considered, our method can achieve the resolution about 0.5 nm within 250 μm displacement. In addition, 2-D in-plane displacement measurement can be accomplished with a single interferometer simultaneously.     

由Lagrange展开产生的一对公式

Let Γ denote the ring of formal power series over the complex field C. Let φ∈Γ with φ(0)=0 and φ′(0)=0 So that it has a compositional inverse ψ with ψ(φ(t))=φ(ψ(t))=1. Then for every f∈Γ and α∈C With α≠0 we have Lagrange′s formal expansion     

Studies on the level structure of154Gd via the β-decay of154Eu nucleus

The excited states of¹⁵⁴Gd populated by theβ-decay of¹⁵⁴Eu (T _1/2=8.5y) have been studied. With a HPGe-NaI (T1) Compton suppression spectrometer and a HPGe-NaI(T1) coincidence circuitυ-ray singles spectra, coincidence spectra and theγ-γ directional correlational functions have been obtained. The deduced mixing ratios of multipolarities are presented. The energy levels and the relativeB(E2) values of the variousγ-transitions in¹⁵⁴Gd nucleus have been calculated both in the IBA model and it's extended version with boson surface delta interaction (BSDI).     

Synthesis of terpyridine ligands and their complexation with Zn2+ and Ru2+ for optoelectronic applications

A series of soluble conjugated ligands TT , FT , PT , and NT that contained terpyridyl terminal units were synthesized by Heck coupling. These ligands absorbed at 341–434 nm and emitted blue–green light, with maximum at 440–522 nm and photoluminescence quantum yields of 0.15–0.71 in solution. The double‐layer electroluminescent devices with the configuration of ITO/PEDOT/ligand FT , PT , or NT /Ca/Al exhibited a brightness of 43–63 cd/m². These ligands were further reacted with zinc(II) and ruthenium(II) ions and subsequent anion exchange to afford linear and supramolecular complexes. The photophysics of these complexes were investigated. A significant redshift of the emission maximum of the Zn complexes relative to the corresponding ligands was observed. The Ru complexes were used to fabricate photovoltaic devices with the structure ITO/PEDOT/Ru complex/P3HT:PCBM (1:1 wt/wt)/Ca/Al. The power conversion efficiency of these polymer–fullerene bulk heterojunction photovoltaic devices was up to 0.71%. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7702–7712, 2008