The measurement of average hydrodynamic velocity in capillary zone electrophoresis

Summary Based on the linear relationship between large sample injection time during hydrodynamic injection and migration time in non-stacking runs, a new method is proposed to measure average hydrodynamic velocity in capillary zone electrophoresis (CZE). Only the migration times for large injections need to be measured in this new approach, so the method is simple. Additionally, a modified Poiseuille equation is proposed to eliminate the deviation involved in Poiseuille’s equation. The average hydrodynamic velocity values determined by our method generally compare favorably with those determined by the modified Poiseuille equation.     

《计算机组成原理》课程教学探讨

针对《计算机组成原理》课程的特点,提出了教学过程中的几点心得。文章分别从教材的选择、教学内容的组织、教学方法的创新、教学工具的使用以及教学效果的实现等几个方面作了介绍。     

Is Vtb≃1?

The strongest constraint on V_tb presently comes from the 3×3 unitarity of the CKM matrix, which fixes V_tb to be very close to one. If unitarity is relaxed, current information from top production at Tevatron still leaves open the possibility that V_tb is sizably smaller than one. In minimal extensions of the standard model with extra heavy quarks, the unitarity constraints are much weaker, and the EW precision parameters entail the strongest bounds on V_tb. We discuss the experimental perspectives of discovering and identifying such new physics models at the Tevatron and the LHC, through a precise measurement of V_tb from the single top cross sections and by the study of processes where the extra heavy quarks are produced.     

Generalized prolate spheroidal wave functions for offset linear canonical transform in Clifford analysis

Prolate spheroidal wave functions (PSWFs) possess many remarkable properties. They are orthogonal basis of both square integrable space of finite interval and the Paley–Wiener space of bandlimited functions on the real line. No other system of classical orthogonal functions is known to obey this unique property. This raises the question of whether they possess these properties in Clifford analysis. The aim of the article is to answer this question and extend the results to more flexible integral transforms, such as offset linear canonical transform. We also illustrate how to use the generalized Clifford PSWFs (for offset Clifford linear canonical transform) we derive to analyze the energy preservation problems. Clifford PSWFs is new in literature and has some consequences that are now under investigation. Copyright © 2012 John Wiley & Sons, Ltd.     

Some improvements of Ostrowski’s method

In this paper, we present some new variants of Ostrowski’s method with order of convergence eight. For each iteration the new methods require three evaluations of the function and one evaluation of its first derivative and therefore they have the efficiency index equal to 1.682. Numerical tests verifying the theory are also given.     

Vector meson-nucleon scattering length $$|alpha _{VN}|$$ and trace anomalous energy contribution to the nucleon mass $$T_{A}$$

The European Physical Journal A - Initially, yields (or abundances) and branching ratios of β-delayed neutrons (βdn) from fission products (Pn-values) have had their main importance in...     

Extraction of proton trace anomaly energy from near-threshold $$phi $$ and $$J/psi $$ photo-productions

The European Physical Journal A - We discuss a phenomenological shell model analysis of the structure of $$^{48,49,50}$$ Ca. Based on simple arguments, we propose wavefunctions fit to the available...     

Fabrication and interfacial morphologies of methanol–melamine–formaldehyde (MMF) shell microPCMs/epoxy composites

Microcapsules containing phase change materials (microPCMs) have many potential applications because of their thermoregulation or thermosaving abilities. At the same time, it is still essential to understand the interface stability of microPCMs/polymer composites during a thermal transmission. The aim of this work was to fabricate novel microPCMs containing dodecanol by an in situ polymerization using methanol-modified melamine–formaldehyde (MMF) prepolymer as shell material and investigate the interface morphologies of microPCMs/epoxy composites treated by a simulant thermal process with a ten times repeated temperature variation. A series of microPCMs were fabricated by 1,000–3,000 r·min⁻¹ emulsion speed with the PCM contents of 40–70%. The average diameter, melting temperature, and encapsulation efficiency of microPCMs were 1–16 μm, 19.5 °C, and 97.4%, respectively. Tests results indicated that the properties of the microPCMs were greatly affected by core/shell ratios and emulsification stirring rates of preparation conditions. With the increasing of stirring rates, the average diameters of microPCMs were sharply decreased. The encapsulation efficiency (E _e) values of microPCMs increased with the increasing of stirring rates. The contents of PCM in microcapsules (C _t) and the average diameter of microPCMs both affected the interface morphologies of microPCMs/epoxy composites after the repeated thermal treatments. Microcracks and gaps occurred after a thermal treatment in the interface of microPCMs and epoxy matrix obviously. The internal stress generated by the expansion or shrinking of the microPCMs was the main factor leading to the interface morphology changes and damaged of composites.