Effects of plasticiser on the lithium ionic conductivity of polymer electrolyte PVC-LiCF3SO3

Solid polymer electrolyte films based on poly(vinyl chloride)-lithium triflate (PVC-LiCF₃SO₃) have been prepared by the solution-cast technique in various concentrations. The film with the highest conductivity was used to prepare plasticised polymer electrolyte films by using poly(ethlene glycol) (PEG) of different molecular weights, i.e., 200, 400 and 600 gmol⁻¹. These films were prepared to study the effects of addition of low molecular weights PEG on the lithium ionic conduction of the PVC based polymer electrolyte. The films were characterised by electrochemical impedance spectroscopy (EIS) and Fourier transform infrared-spectroscopy (FTIR). Results indicate that the molecular weight has an inverse effect on the conductivity and this has been accounted for by FTIR. Paper presented at the International Conference on Functional Materials and Devices 2005, Kuala Lumpur, Malaysia, June 6 – 8, 2005.     

Energy limits imposed by two-photon absorption for pulse amplification in high-power semiconductor optical amplifiers

We study the combined effects of dynamic gain saturation and two-photon absorption on the amplification of short pulses in semiconductor optical amplifiers and show that two-photon absorption can saturate the amplifier gain and limit the output pulse energies even for amplifiers with large gain saturation energies. We discuss the upper limits for the pulse energies obtainable from semiconductor optical amplifiers in the presence of two-photon absorption and show that for single transverse mode waveguide amplifiers these upper limits can range from values as small as a few picojoules to several hundred picojoules for pulse widths in the 0.5 ps to 20 ps range, respectively.     

Search for a standard model Higgs boson in the H→ZZ→ℓ(+)ℓ(-)νν decay channel with the ATLAS detector

A search for a heavy standard model Higgs boson decaying via H→ZZ→→?(+)?(-)νν, where ?=e, μ, is presented. It is based on proton-proton collision data at √s=7 TeV, collected by the ATLAS experiment at the LHC in the first half of 2011 and corresponding to an integrated luminosity of 1.04 fb(-1). The data are compared to the expected standard model backgrounds. The data and the background expectations are found to be in agreement and upper limits are placed on the Higgs boson production cross section over the entire mass window considered; in particular, the production of a standard model Higgs boson is excluded in the region 340相似文献   

Evaluation of the magnetic moments of radium isotopes

Using the relativistic linked cluster many-body perturbation procedure we have obtained the hyperfine field at the nucleus of the Ra⁺ ion in the²S_1/2 ground state. There is good agreement between the calculated magnetic moment of²¹³Ra and the results of a recent Zeeman measurement by the collinear laser beam technique. Detailed comparison is carried out between our result and earlier ones.     

Interaction of Point Defects with Twin Boundaries in Copper

The interaction between small vacancy clusters and twin boundaries in copper is studied by using many-body potential developed by Ackland et aL for fcc metals. The interaction energies of single-, di- and tri-vacancy clusters with （111） and （112） twin boundaries are computed using well established simulation techniques. For （111） twins the vacancy clusters are highly repelled when they are on the adjacent planes, and are attracted when they are away from the boundary. In the case of （112） twins, vacancy clusters are more attracted to the boundary when they are near the boundary as compared to away from it. Vacancy clusters on both the sides of the boundary are also investigated, and it is observed that the clusters energetically prefer to lie on the off-mirror sites as compared to the mirror position across the twin.     

On the accuracy of bore reconstruction from input impedance measurements: application to bassoon crook measurements

The determination of a pipe bore from the measured reflection function is a technique that has reached a certain maturity. However, the measurement of the reflection function in the time domain (pulse reflectometry) requires equipment that is rather difficult to operate. On the other hand, the techniques for measuring the input impedance have reached an unquestionable maturity with respect to measurement setup and to calibration. It is thus likely that impedance measurements might be able to give the same information. By doing simulations, it is first shown that the reflection function deduced from the input impedance gives access to the bore with a precision comparable with that obtained with pulse reflectometry. It is then shown that the accuracy obtained with measurements is of the same order as that obtained from simulations. The technique is then used for the dimensional inspection of bassoon crooks.     

Numerical simulation of unsteady 3D magneto-Sisko fluid flow with nonlinear thermal radiation and homogeneous–heterogeneous chemical reactions

In this paper, we study the qualitative behaviour of satellite systems using bifurcation diagrams, Poincaré section, Lyapunov exponents, dissipation, equilibrium points, Kaplan–Yorke dimension etc. Bifurcation diagrams with respect to the known parameters of satellite systems are analysed. Poincaré sections with different sowing axes of the satellite are drawn. Eigenvalues of Jacobian matrices for the satellite system at different equilibrium points are calculated to justify the unstable regions. Lyapunov exponents are estimated. From these studies, chaos in satellite system has been established. Solution of equations of motion of the satellite system are drawn in the form of three-dimensional, two-dimensional and time series phase portraits. Phase portraits and time series display the chaotic nature of the considered system.     

Highly efficient and high output power of erbium doped fiber laser in a linear cavity configuration

A simple Erbium Doped Fiber Laser (EDFL) in linear cavity configuration is reported. The cavity design is based on an FBG as a back reflector, and a loop back optical circulator with an output coupler as the front reflector. Different coupling ratios of the coupler are tested and 50: 50 provides the highest coupling output power of 22.06 dBm (160.7 mW). The pump power conversion efficiency is about 95% when pumping with two pump lasers at 1460 and 1490 nm with combined pumping power of 545 mW. The laser output has a measured linewidth of 0.0179 nm.     

Ultra-broadband near-infrared pulse generation by noncollinear OPA with angular dispersion compensation

A scheme for the generation of an ultra-broadband, near-infrared beam from a Ti:sapphire source is proposed with the aim to serve as seed pulse of a petawatt-field synthesizer (Major et al. in Rev. Laser Eng. 37:431, 2009). The idler beam of a noncollinear optical parametric amplifier, pumped at the second harmonic of the Ti:sapphire output, displays the required bandwidth, albeit with an inherent angular chirp owing to the noncollinear geometry. We propose a scheme for the compensation of this angular dispersion which consists of a diffraction grating, a telescope and a deformable mirror. The suitability of this scheme is discussed quantitatively and preliminary experimental findings are shown.