Static properties and semileptonic decays of doubly heavy baryons in a nonrelativistic quark model

We evaluate static properties and semileptonic decays for the ground state of doubly heavy Ξ, Ξ', Ξ ^* and Ω, Ω', Ω ^* baryons. Working in the framework of a nonrelativistic quark model, we solve the three-body problem by means of a variational ansatz made possible by heavy-quark spin symmetry constraints. To check the dependence of our results on the inter-quark interaction we use five different quark-quark potentials that include a confining term plus Coulomb and hyperfine terms coming from one-gluon exchange. Our results for static properties (masses, charge radii and magnetic moments) are, with a few exceptions for the magnetic moments, in good agreement with a previous Faddeev calculation. Our much simpler wave functions are used to evaluate semileptonic decays of doubly heavy Ξ, Ξ'(J = 1/2) and Ω, Ω'(J = 1/2) baryons. Our results for the decay widths are in good agreement with calculations done within a relativistic quark model in the quark-diquark approximation. An erratum to this article is available at .     

SEQUENTIAL CONVEX PROGRAMMING METHODS FOR SOLVING LARGE TOPOLOGY OPTIMIZATION PROBLEMS： IMPLEMENTATION AND COMPUTATIONAL RESULTS

In this paper, we describe a method to solve large-scale structural optimization problems by sequential convex programming （SCP）. A predictor-corrector interior point method is applied to solve the strictly convex subproblems. The SCP algorithm and the topology optimization approach are introduced. Especially, different strategies to solve certain linear systems of equations are analyzed. Numerical results are presented to show the efficiency of the proposed method for solving topology optimization problems and to compare different variants.     

TOPCMTC模型中π~"非汉字符号"介子与W~±规范玻色子在LHC上的辅助产生(英文)

在顶色辅助多标度人工色 (TOPCMTC)模型下计算了大动量强子对撞机 (LHC)上π 介子与W± 规范玻色子辅助产生过程pp→b b→W±π 的产生截面 .发现这个产生截面与最小超对称模型下pp→b b→W±H 的相应结果大致相当 .在一定的参数范围内 ,这个过程的产生截面能够达到几十个甚至一百多个fb .W±π 的信息可能在LHC上被探测到 .     

Modelling of two-phase,transient airflow and particles distribution in the indoor environment by Large Eddy Simulation

Prediction of particles distribution in the smaller-scale atmospheric environment, such as the indoor atmosphere, is of major importance for the comfort and the well-being of its occupants. The objective of this study is to investigate the airflow and particles transport, as well as the particles concentration evolution indoors, using Computational Fluid Dynamics (CFD) techniques. A three-dimensional, Euler–Euler two-phase flow model for the investigation of the indoor aerosol is developed, within a CFD general-purpose computer program (PHOENICS), and is validated against experimental measurements from the literature, for an ordinary case of indoor dilute aerosol. Turbulent flow is simulated by Large Eddy Simulation (LES) and the results are compared with those obtained applying the Reynolds-averaged Navier–Stokes (RANS) equations together with the ReNormalisation Group (RNG) k–? model. Τwo-way coupling between the two phases is modelled by means of appropriate interphase interactions. This study focused on particles of one size group (mean aerodynamic diameter of 10 μm) but the numerical method described can equally well be applied for a broader size range. It is concluded that for the very dilute aerosols considered here, simpler models (such as single-phase and drift flux) do as well in predicting the important parameters of the flow, as the more complex ones.     

Determination of multiclass pesticide residues in apple juice by gas chromatography-mass spectrometry with large-volume injection

This study presents two GC-MS SIM methods, in combination with large-volume injection programmed-temperature vaporization (LVI-PTV) injection, for the determination of 141 pesticide residues in apple juice. The sample was extracted with ACN, and coextractives were removed with primary/secondary amine sorbent. ACN extract (20 microL) was injected into a PTV injection port in solvent vent mode, and the pesticides were determined by GC-MS using retention time locking software. Deuterium-labeled pesticides (surrogate standards) were used for analytical quality control. In the validation experiments, pesticides recoveries were found to be 70-121% with RSDs of 4.6-21% (n = 6).     

特殊重尾随机变量随机和的大偏差

文献[1]对于一些经典重尾随机变量的随机和大偏差作了有意义的讨论,本文则讨论了另外一些同样有用的重尾随机和的大偏差.     

Combination of solid-phase extraction and large-volume stacking with polarity switching in micellar electrokinetic capillary chromatography for the determination of traces of nonsteroidal anti-inflammatory drugs in saliva

A reliable MEKC method for the identification and quantitation of traces of the nonsteroidal anti-inflammatory drugs (NSAIDs) ketoprofen, fenbufen and indomethacin in saliva is proposed. Using CE to analyze biological samples often requires suppressing the interferences and peak broadening typically resulting from high-conductivity sample matrices. We addressed this problem by using Microcon, a centrifugal filter device, to reduce the viscosity of saliva and exclude most higher-molecular-mass substances. This initial pretreatment was followed by the combined used of off-line SPE to isolate and concentrate the analytes, and large-volume stacking with polarity switching (LVSS) in the capillary. These two preconcentration steps allow the determination of NSAIDs at concentrations above 0.1 microg/L; therefore, the proposed SPE/LVSS/MEKC method affords a 500-fold sensitivity enhancement relative to conventional CE injection. The LODs obtained afford the determination of NSAIDs in saliva, where analytes can be present at the microgram-per-liter level.     

Dynamic analysis of a dielectric elastomer-based microbeam resonator with large vibration amplitude

A non-linear vibration equation with the consideration of large amplitude, gas damping and excitation is developed to investigate the dynamic performance of a dielectric elastomer (DE)-based microbeam resonator. Approximate analytical solution for the vibration equation is obtained by applying parameterized perturbation method (PPM) and introducing a detuning variable. The analysis exhibits that active tuning of the resonant frequency of the resonator can be achieved through changing an applied electrical voltage. It is observed that increasing amplitude will increase the natural frequency while it will decrease the quality factor of the resonator. In addition, it is found that the initial pre-stretching stress and the ambient pressure can significantly alter the resonant frequency of the resonator. The analysis is envisaged to provide qualitative predictions and guidelines for design and application of DE-based micro resonators with large vibration amplitude.     

Uniform asymptotics for compound Poisson processes with regularly varying jumps and vanishing drift

This paper addresses heavy-tailed large-deviation estimates for the distribution tail of functionals of a class of spectrally one-sided Lévy processes. Our contribution is to show that these estimates remain valid in a near-critical regime. This complements recent similar results that have been obtained for the all-time supremum of such processes. Specifically, we consider local asymptotics of the all-time supremum, the supremum of the process until exiting $[0,\infty )$, the maximum jump until that time, and the time it takes until exiting $[0,\infty )$. The proofs rely, among other things, on properties of scale functions.     

The nuclear medicine production and delivery problem

Half-life is a unique characteristic of radioactive substances used in a variety of medical treatments. Radioisotope F-18 used for diagnosing and monitoring many types of cancers has a half-life of 110 minutes. As such, it requires careful coordination of production and delivery by manufacturers and medical end-users. To model this critical production and delivery problem, we develop a mixed integer program and propose a variant of a large neighborhood search algorithm with various improvement algorithms. We conduct several computational experiments to demonstrate the effectiveness of the proposed approach. The method when applied in a case study shows that improvement in terms of both time and cost is possible in the production and delivery of F-18.