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961.
Meenu Thakur B. R. Behera Ruchi Mahajan N. Saneesh Gurpreet Kaur Priya Sharma R. Dubey Kushal Kapoor A. Yadav Neeraj Kumar S. Kumar Kavita Rani P. Sugathan A. Jhingan A. Chatterjee M. B. Chatterjee S. Mandal A. Saxena Santanu Pal S. Kailas Avazbek Nasirov Bakhodir Kayumov 《The European Physical Journal A - Hadrons and Nuclei》2017,53(6):133
962.
In this paper, the governing relations and equations are derived for nonlocal elastic solid with voids. The propagation of time harmonic plane waves is investigated in an infinite nonlocal elastic solid material with voids. It has been found that three basic waves consisting of two sets of coupled longitudinal waves and one independent transverse wave may travel with distinct speeds. The sets of coupled waves are found to be dispersive, attenuating and influenced by the presence of voids and nonlocality parameters in the medium. The transverse wave is dispersive but non-attenuating, influenced by the nonlocality and independent of void parameters. Furthermore, the transverse wave is found to face critical frequency, while the coupled waves may face critical frequencies conditionally. Beyond each critical frequency, the respective wave is no more a propagating wave. Reflection phenomenon of an incident coupled longitudinal waves from stress-free boundary surface of a nonlocal elastic solid half-space with voids has also been studied. Using appropriate boundary conditions, the formulae for various reflection coefficients and their respective energy ratios are presented. For a particular model, the effects of non-locality and dissipation parameter (\(\tau \)) have been depicted on phase speeds and attenuation coefficients of propagating waves. The effect of nonlocality on reflection coefficients has also been observed and shown graphically. 相似文献
963.
In the present work,nonlinear interaction of elliptical laser beam with collisional plasma is studied by using paraxial ray approximation.Nonlinear differential equations for the beam width parameters of semi-major axis and semi-minor axis of elliptical laser beam have been set up and solved numerically to study the variation of beam width parameters with normalized distance of propagation.Effects of variation in absorption coefficient and plasma density on the beam width parameters are also analyzed.It is observed from the analysis that extent of self-focusing of beam increases with increase/decrease in plasma density/absorption coefficient. 相似文献
964.
Synchrotron radiation induced X‐ray production cross sections of 66Dy at energies across its Li (i = 1–3) subshell absorption edges 下载免费PDF全文
The X‐ray production (XRP) cross sections for the 66Dy Lk (k = l, α, η, β2,6,7,15, β1,6, β1,3,4,6, β2,7,15, γ1,5, γ2,3) emission lines have been measured by tuning the incident synchrotron radiation at energies over the range 7.8–9.2 keV and ~10–370 eV above the respective Li (i = 1–3) absorption edges. These measurements aim to check the reliability of the independent particle approximation models used to generate the theoretical data sets of different physical parameters required to calculate the XRP cross sections and also investigate the influence of many body effects on the photoionization process. The measured values have been compared with 4 sets of XRP cross sections calculated using the Dirac–Fock model‐based X‐ray emission rates, 2 sets of the Li (i = 1–3) subshell photoionization cross sections deduced from the self‐consistent Dirac–Hartree–Fock model‐based values and the nonrelativistic Hartree–Fock–Slater model‐based values, and 2 sets of the fluorescence (ωi) and Coster–Kronig (fij) yields. The present measured Lγ2,3 (originating from decay of the L1 subshell vacancies) XRP cross sections are found to be significantly higher than different sets of theoretical values, whereas a good agreement is generally observed for the various other XRP cross sections and relative intensities. 相似文献
965.
Microwave‐assisted facile synthesis of propargylamine library by robust nitro functionalized cross‐linked polystyrene resin supported Cu NPs 下载免费PDF全文
In the present investigation, we study catalytic activity of copper nanoparticles stabilized onto a nitro functionalized polystyrene resin (Cu NPs@ Nitro‐Resin). The size of stabilized copper nanoparticles was found between 3 and 9 nm. This work reports a cost‐effective and sustainable protocol for the synthesis of propargylamines. Herein, we have developed microwave‐assisted synthesis of propargylamine from 3 components coupling of aldehyde, alkynes, and amines (A3 coupling) in truly heterogeneous catalytic system. Reaction parameters, such as solvent, catalyst concentration reaction time, and recyclability, were investigated, and reaction conditions were optimized. The present method has advantages such as environmentally benign, ease to handle, short reaction time (≈25 min), excellent yields (98%), low E‐factor (0.15), and high atom economy (94%). 相似文献
966.
Swift heavy ions interact predominantly through inelastic scattering while traversing any polymer medium and produce excited/ionized
atoms. Here samples of the polycarbonate Makrofol of approximate thickness 20 μm, spin coated on GaAs substrate were irradiated
with 50 MeV Li ion (+3 charge state). Build-in modifications due to irradiation were studied using FTIR and XRD characterizations.
Considerable changes have been observed in the polymer while varying the fluence from 1E11 ion/cm2 to 1E13 ion/cm2 Li ions. AFM images of the surface modifications caused by ion irradiation on the polymer are also presented.
相似文献
967.
Artificial Neural Networks are developed as an important technique for equalization and have been widely used to mitigate the nonlinear effects in coherent optical systems. For the compensation of nonlinearities in coherent optical orthogonal frequency division multiplexing technique, the most popular artificial neural network model is a multilayer perceptron (MLP), as it is able to perform complex mapping between input and output spaces with significant success. However due to the complexity of multilayer perceptron nonlinear equalizer (MLP-NLE) model training of neural network is difficult. To overcome computational complexity issues of MLP-NLE, a single neuron based functional link artificial neural network nonlinear equalizer (FLANN-NLE) has been developed in this paper. Better performance of an equalizer is attributed to the usage of aPSO-BP algorithm for training the FLANN-NLE. The proposed FLANN-NLE surpasses the existing works both in terms of Q-Factor and computational complexity. For a fiber length of 1000 km and at launch power of ?6 dBm, the improvement in Q-Factor is approximately equal to 3.3 and 1 dB in contrast to the previously reported values of approximately 3 and 0.7 dB at bit rate of 40 and 80 Gbps respectively. 相似文献
968.
Parvesh Gangwani Ravneet Kaur Sujata Pandey Subhasis Haldar Mridula Gupta R.S. Gupta 《Superlattices and Microstructures》2008
The paper presents an accurate charge control model for a fully strained (FS), and partially relaxed (PR) lattice mismatched AlGaN/GaN HEMT, taking into consideration the effect of spontaneous and piezoelectric polarization. The model also accounts for the mobility degradation with increase in temperature, which is one of the major causes in deterioration of the driving current. By using the variation of band gap with temperature, the temperature dependence on threshold voltage, sheet carrier concentration and drain current is studied. Further, the temperature variation shows the applicability of the device in a variable thermal environment. A close agreement of calculated data with simulated/experimental data proves the validity of the model. 相似文献
969.
The synthesis of 4′-(2-methylphenyl)-2,2′:6′,2″-terpyridine (L) has been improved. The coordination chemistry of the ligand was explored using Ni(II), Cu(II), Zn(II), and Ag(I) ions. X-ray crystallography, elemental analysis, NMR, and mass spectrometry were used to characterize the 13 new compounds that have been synthesized. Under different reaction conditions, Ni(II), Cu(II), and Zn(II) produced discrete complexes, sometimes containing more than one metal ion, while Ag(I) furnished a polymeric spiral complex in which the central pyridine nitrogen of each terpyridine ligand bridges two Ag(I) ions. Crystallographically characterized complexes are [Ni(L)2]Cl2, [Ni2Cl4(L)2], [Ni(L)(OH2)3]Cl2, [Ni(L)2]Br2, [Cu(L)(OH2)(OSO3)], [Cu3Cl6(L)2], [Cu(L)(OH)(OH2)2]PF6, [Cu(L)2](OTf)2, [Cu(L)(OAc)2], [Zn(L)(OAc)2], [Zn(L)Cl2], [Zn(L)2](NO3)2, [{Ag2(μ-L)2(μ-NO3)}n](NO3)n. 相似文献
970.
Jasvir Kaur Neetu Singh Yadav Moirangthem Kiran Singh Mohd Jahir Khan Sobhan Sen Aparna Dixit Devapriya Choudhury 《Photochemistry and photobiology》2019,95(2):543-555
The photophysics of green fluorescent protein (GFP) is remarkable because of its exceptional property of excited state proton transfer (ESPT) and the presence of a functional proton wire. Another interesting property of wild‐type GFP is that its absorption and fluorescence excitation spectra are sensitive to the presence of polar organic solvents even at very low concentrations. Here, we use a combination of methodologies including site‐specific mutagenesis, absorption spectroscopy, steady‐state and time‐resolved fluorescence measurements and all‐atom molecular dynamics simulations in explicit solvent, to uncover the mechanism behind the unique spectral sensitivity of GFP toward organic solvents. Based on the evidences provided herein, we suggest that organic solvent‐induced changes in the proton wire prevent ground state movement of a proton through the wire and thus bring about the spectral changes observed. The present study can not only help to understand the mechanism of proton transfer by further dissecting the intricate steps in GFP photophysics but also encourages to develop GFP‐based organic solvent biosensors. 相似文献