A family of multiple harmonic sum and multiple zeta star value identities

In this paper we present a new family of identities for multiple harmonic sums which generalize a recent result of Hessami Pilehrood et al [Trans. Amer. Math. Soc. (to appear)]. We then apply it to obtain a family of identities relating multiple zeta star values to alternating Euler sums. In such a typical identity the entries of the multiple zeta star values consist of blocks of arbitrarily long 2-strings separated by positive integers greater than two while the largest depth of the alternating Euler sums depends only on the number of 2-string blocks but not on their lengths

Quarks, diquarks and QCD mixing in the N∗N^* resonance spectrum

We identify a "$\Lambda$ selection rule" for $N^*$ resonances in the presence of QCD mixing effects. We quantify these mixing effects from existing data and predict amplitudes for exciting {\bf 20} representations in SU(6), which are forbidden in strict diquark models. By classifying Particle-Data-Group (PDG) states at N=2, we show that $\gamma N\to K\Lambda$, $K^*\Lambda$, $K\Sigma$, $K^*\Sigma$, and $J/\psi \to \bar{p}N^*$ are ideal probes of baryon dynamics and for establishing whether strongly correlated diquarks survive for $L > 0$.Comment: Extended version accepted by PR

Restricted locality of quark-hadron duality in exclusive meson photoproduction reactions above the resonance region

We show how deviations from the dimensional scaling laws for exclusive processes may be related to a breakdown in the locality of quark-hadron duality, i.e. the "restricted locality". For exclusive reactions like meson photo- and electroproduction above the resonance region, we explore the effects arising from such a local duality breaking and propose that it can be a possible source for oscillations about the smooth quark counting rule predicted by pQCD in the 90-degree differential cross sections.Comment: Contribution to the 10th International Symposium on Meson-Nucleon Physics and the Structure of the Nucleon (MENU2004), Beijing, 2004; presented by Q

Academic institutional repositories in China: A survey of CALIS member libraries

Purpose: China Academic Library &amp; Information System (CALIS) planned to launch an institutional repository (IR) project to promote IR development and open access at colleges and universities in China. In order to get to know the current state of IRs in academic institutions, with the help of Peking University Library, CALIS Administrative Center conducted this survey.Design/methodology/approach: We conducted an online survey of CALIS member libraries.Findings: Firstly, the development of IRs at China's colleges and universities is still in its infancy. Secondly, the Chinese colleges and universities have reached a consensus on the objective for having an IR. Thirdly, they are having high expectations of IR&nbsp;functions. Fourthly, they prefer to establish a centralized IR system at a minimum cost. Finally, there are both similarities and differences between the Chinese academic institutions and their counterparts in other countries in the state of IR development.Research limitations: The questionnaire needs to be improved because there is a lack of enough questions for those who do not plan to build an IR. Comparatively lower rate of valid questionnaire return can affect the accuracy of the results. It is hard to go into an in-depth discussion only based on the data collected from this questionnaire survey, and consequently, the findings from the survey can hardly present an accurate and comprehensive picture of the current state of IR development in the academic sector in China.Practical implications: The survey results provide essential foundation for CALIS IR project, and meanwhile the research can serve as a reference source for the future studies of the development of IRs at China's colleges and universities.Originality/value: It is the first national survey focused on the development of IRs in academic institutions in China.</p

Dynamic modeling of α in the isotropic lagrangian averaged navier-stokes-α equations

A dynamic procedure for the Lagrangian Averaged Navier- Stokes-α (LANS-α) equations is developed where the variation in the parameter α in the direction of anisotropy is determined in a self-consistent way from data contained in the simulation itself. In order to derive this model, the incompressible Navier-Stokes equations are Helmholtz-filtered at the grid and a test filter levels. A Germano type identity is derived by comparing the filtered subgrid scale stress terms with those given in the LANS-α equations. Assuming constant α in homogenous directions of the flow and averaging in these directions, results in a nonlinear equation for the parameter α, which determines the variation of α in the non-homogeneous directions or in time. Consequently, the parameter α is calculated during the simulation instead of a pre-defined value. As an initial test, the dynamic LANS-α model is used to compute isotropic homogenous forced and decaying turbulence, where α is constant over the computational domain, but is allowed to vary in time. The resulting simulations are compared with direct numerical simulations and with the LANS-α simulations using fixed value of α. As expected, α is found to change rapidly during the first eddy turn-over time during the simulations. It is also observed that by using the dynamic LANS-α procedure a more accurate simulation of the isotropic homogeneous turbulence is achieved. The energy spectra and the total kinetic energy decay are captured more accurately as compared with the LANS-α simulations using a fixed α. The current results suggest some promising applications of this dynamic LANS-α model, such as to a spatially varying turbulent flow, which we hope to undertake in future research