A New Capillary Electrophoresis Apparatus with Piezoelectric Ceramics High Voltage Source and Amperometric Detector

IntroductionHighperformancecapiliar}'electrophoresis(HPCE)isanewanalyticaltechnology'rapidly'developedinrecentyears.Withtheadvantagesofsmallsample.highsensitivity,highresolution.rapidanalysisandverycheaprunning,ithasbeenappliedinchemistry'.lifescienc...     

Quark see-saw,Higgs mass and vacuum stability

The issue of vacuum stability of standard model (SM) is discussed by embedding it within the TeV scale left–right quark see-saw model. The Higgs potential in this case has only two coupling parameters (λ₁, λ₂) and two mass parameters. There are only two physical neutral Higgs bosons (h,H), the lighter one being identified with the 126 GeV Higgs boson. We explore the range of values for (λ₁, λ₂) for which the vacuum is stable for all values of the Higgs fields till 10¹⁶ GeV. Combining with the further requirement that the scalar self-couplings remain perturbative till 10¹⁶ GeV, we find (i) an upper and lower limit on the second Higgs (H) mass to be within the range: 0.4 ≤ (M_H/v_R) ≤ 0.7, where v_R is the parity breaking scale and (ii) the masses of heavy vector-like top, bottom and τ partner fermions (P₃, N₃,E₃) have an upper bound ≤ v_R. These predictions can be tested at LHC and future higher energy colliders.     

MODELLING DYNAMICS OF A CONTINUOUS STRUCTURE WITH A PIEZOELECTRIC SENSORACTUATOR FOR PASSIVE STRUCTURAL CONTROL

This paper presents the concept of a vibration control system in which motions of a continuous structure with piezoelectric sensors/actuators can be suppressed (or activated) through transforming mechanical energy to electrical one and vice versa. The study is focused on distributed parameter structures, in which electromechanical variables are spatially dependent, and therefore traditional methods of design of piezoelectric transformers do not apply. In this case, a different approach is necessary to account for the spatial dependency of the variables. To examine the feasibility of the proposed vibration control system, we have performed the vibration suppression analysis of the cantilevered beam with piezoelectric sensors/actuators subjected to an exciting force/moment(s). The experimental results indicate that the damping of the composite system increases by 8-10 times in comparison with the mechanical system.As a result, the paper significantly expands the concept of passive damping mechanism for structural systems to take into account the dynamics of a continuous elastic structure piezoelectrically coupled to electrical network.     

Grafting of Hexafluoropropylene onto Polytetramethylene Glycol by Radical Reaction

A well-defined modification of polytetramethylene glycol （PTMG） was realized by radical grafting with hexafluoropropylene （HFP）. The structure of grafted product was confirmed by means of IR, ^1H NMR and ^13C NMR. The effects of the amount of initiator, reaction time and temperature on the grafting HFP onto PTMG were investigated.