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11.
Linear and nonlinear optical analysis on semiorganic-proline cadmium chloride single crystal 下载免费PDF全文
In the current investigation,L-proline cadmium chloride monohydrate(LPCC) single crystal is grown by a slow solvent evaporation technique to identify its credibility for nonlinear optical device applications.The constituent elements of LPCC crystal are determined by the energy dispersive spectroscopic(EDS) technique.The single crystal x-ray diffraction technique is used to determine the structural dimensions of LPCC crystal.The UV-visible studies are carried out within a wavelength range of 200 nm–1100 nm to determine the optical transmittance of LPCC crystal.The linear optical parameters of LPCC crystal are evaluated using the transmittance data to discuss its importance for distinct optical devices.The Nd:YAG laser assisted Kurtz–Perry test is carried out to determine the enhancement in second harmonic generation efficiency of LPCC crystal with reference to KDP crystal.The Z-scan technique is employed to assess the third order nonlinear optical(TONLO) properties of LPCC crystal at 632.8 nm.The Z-scan data are utilized to evaluate the TONLO refraction,absorption and susceptibility of LPCC crystal.The color oriented luminescence behavior of LPCC crystal is investigated within a spectral range of 350 nm–700 nm.The dependence of dielectric constant and dielectric loss on temperature and frequency is evaluated through the dielectric measurement studies. 相似文献
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This paper discusses two stochastic approaches to computing the propagation of uncertainty in numerical simulations: polynomial
chaos and stochastic collocation. Chebyshev polynomials are used in both cases for the conventional, deterministic portion
of the discretization in physical space. For the stochastic parameters, polynomial chaos utilizes a Galerkin approximation
based upon expansions in Hermite polynomials, whereas stochastic collocation rests upon a novel transformation between the
stochastic space and an artificial space. In our present implementation of stochastic collocation, Legendre interpolating
polynomials are employed. These methods are discussed in the specific context of a quasi-one-dimensional nozzle flow with
uncertainty in inlet conditions and nozzle shape. It is shown that both stochastic approaches efficiently handle uncertainty
propagation. Furthermore, these approaches enable computation of statistical moments of arbitrary order in a much more effective
way than other usual techniques such as the Monte Carlo simulation or perturbation methods. The numerical results indicate
that the stochastic collocation method is substantially more efficient than the full Galerkin, polynomial chaos method. Moreover,
the stochastic collocation method extends readily to highly nonlinear equations. An important application is to the stochastic
Riemann problem, which is of particular interest for spectral discontinuous Galerkin methods. 相似文献
14.
A general framework is proposed for what we call the sensitivity derivative Monte Carlo (SDMC) solution of optimal control problems with a stochastic parameter. This method employs the residual in the first-order Taylor series expansion of the cost functional in terms of the stochastic parameter rather than the cost functional itself. A rigorous estimate is derived for the variance of the residual, and it is verified by numerical experiments involving the generalized steady-state Burgers equation with a stochastic coefficient of viscosity. Specifically, the numerical results show that for a given number of samples, the present method yields an order of magnitude higher accuracy than a conventional Monte Carlo method. In other words, the proposed variance reduction method based on sensitivity derivatives is shown to accelerate convergence of the Monte Carlo method. As the sensitivity derivatives are computed only at the mean values of the relevant parameters, the related extra cost of the proposed method is a fraction of the total time of the Monte Carlo method. 相似文献
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We go back and forth between, on the one hand, presentations of arithmetic and Kac-Moody groups and, on the other hand, presentations of profinite groups, deducing along the way new results on both. 相似文献
16.
Sunusi Y. Hussaini Rosenani A. Haque Jing‐Hong Li Shun‐Ze Zhan Kong Wai Tan Mohd. R. Razali 《应用有机金属化学》2019,33(6)
A new series of N‐heterocyclic carbene (NHC) ligand precursors ( 1 and 2 ) with their [Ag(I)(NHC)2]PF6 complexes ( 3 and 4 ) and [ClAu(I)(NHC)] complexes ( 5 and 6 ) are reported. Complexes 5 and 6 were synthesized via transmetalation reaction using either 3 or 4 and AuCl(SMe2) as reactants, respectively. All the synthesized compounds were fully characterized using elemental analyses and Fourier transform infrared, 1H NMR and 13C NMR spectroscopies. In the crystal structures of 3 , 5 and 6 , the Ag(I) and Au(I) ions are in a linear geometry. The entire structure of 3 is stabilized by significant π–π interactions, while the structures of 5 and 6 are stabilized with the presence of aurophilic interactions between the adjacent Au(I) ions as well as CH–π or π–π interactions. From photoluminescence studies, complexes 5 and 6 show dual‐emission characteristics. The higher‐energy fluorescence originates from 1XLCT mixed with 1MLCT, while the lower‐energy phosphorescence is ascribed to 3XLCT and 3MLCT with small contribution of 3ILCT, as evidenced by density functional theory (DFT) and time‐dependent DFT calculations of the modelled molecules. 相似文献
17.
This paper reports on the simulation of the near-nozzle region of an isothermal Mach 0.6 jet at a Reynolds number of 100,000
exhausting from a round nozzle geometry. The flow inside the nozzle and the free jet outside the nozzle are computed simultaneously
by a high-order accurate, multi-block, large eddy simulation (LES) code with overset grid capability. The total number of
grid points at which the governing equations are solved is about 50 million. The main emphasis of the simulation is to capture
the high frequency noise generation that takes place in the shear layers of the jet within the first few diameters downstream
of the nozzle exit. Although we have attempted to generate fully turbulent boundary layers inside the nozzle by means of a
special turbulent inflow generation procedure, an analysis of the simulation results supports the fact that the state of the
nozzle exit boundary layer should be characterized as transitional rather than fully turbulent. This is believed to be most
likely due to imperfections in the inflow generation method. Details of the computational methodology are presented together
with an analysis of the simulation results. A comparison of the far field noise spectrum in the sideline direction with experimental
data at similar flow conditions is also carried out. Additional noise generation due to vortex pairing in the region immediately
downstream of the nozzle exit is also observed. In a second simulation, the effect of the nozzle exit boundary layer thickness
on the vortex pairing Strouhal frequency (based on nozzle diameter) and its harmonics is demonstrated. The limitations and
deficiencies of the present study are identified and discussed. We hope that the lessons learned in this study will help guide
future research activities towards resolving the pending issues identified in this work.
Presented as AIAA Paper 2006-2499 at 12th AIAA/CEAS Aeroacoustics Conference, 8–10 May 2006, Cambridge, MA, USA. 相似文献
Presented as AIAA Paper 2006-2499 at 12th AIAA/CEAS Aeroacoustics Conference, 8–10 May 2006, Cambridge, MA, USA. 相似文献
18.
New polymeric based materials: terpoly(aniline,diphenyl amine,and o‐anthranilic acid) / kaolinite composites 下载免费PDF全文
Ayman S. Al‐Hussaini 《先进技术聚合物》2016,27(12):1604-1608
Terpolymers of aniline, diphenyl amine and o‐anthranilic acid (PANIDPAA) / kaolinite clay composites were synthesized by 1:1:1 molar ratios of the respective monomers with different percentages of kaolinite clay particles via in situ chemical terpolymerization. The spectral characteristics upon incorporation of o‐anthranilic acid and diphenyl amine units into the polyaniline backbone in presence of kaolinite clay were investigated. The results were justified by measuring the UV–Vis absorption spectra, FT‐IR for PANIDPAA emeraldine base (EB), and PANIDPAA EB / kaolinite clay composite. Also, the thermal gravimetric analyses for the isolated terpolymer powder in the bulk in absence and in presence of kaolinite clay were carried out. Moreover, the morphology of the polymer clay composites system was studied by the scanning electron microscope micrographs at different magnifications. X‐ray diffraction was used to measure the nature of polymer and extent of crystallinity present in the neat terpolymer and terpolymer / kaolinite composite materials. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
19.
We report herein the synthesis of cytotoxic cyanobactin, Wewakazole B through an efficient solution-phase approach. The key steps of the synthesis are the macrocyclic lactamization of linear dodecapeptide and construction of two hexapeptides with three different substituted oxazole rings. 相似文献
20.
Beheshti A Clegg W Dale SH Hyvadi R Hussaini F 《Dalton transactions (Cambridge, England : 2003)》2007,(27):2949-2956
Reactions of AgI with salts of [WS(4)](2-) or [MoS(4)](2-) and with either imidazolidine-2-thione (Imt) or [1,3]diazepane-2-thione (Diap) give the complexes [WS(4)Ag(2)(Imt)(2)](n) and [MS(4)Ag(2)(Diap)(4)] [M = W or Mo]; in the case of Diap, corresponding Cu complexes can be obtained with CuCl instead of AgI. Decomposition of the Ag-Diap complexes during attempted recrystallization leads to the polymeric complex [AgI(Diap)](n). The monomeric mixed-metal Diap complexes contain edge-sharing WS(4) and AgS(4) tetrahedra, the Diap ligands being terminally bonded to Ag through sulfur. The mixed-metal W-Ag-Imt complex is a chain polymer with two different environments for the WS(4) unit and three different coordination environments for Ag, one of which is an unprecedented AgS(5) square-based pyramid; Imt ligands are terminally coordinated to Ag. [AgI(Diap)](n) has a complex polymeric chain structure with three different distorted tetrahedral environments for Ag, direct Ag-Ag bonding, both bridging and terminal I, and all Diap ligands bridging pairs of Ag atoms. All the crystal structures feature N-H[...]S or N-H[...]I hydrogen bonding. The complexes have also been characterised by infrared, UV-Vis and (1)H and (13)C NMR spectroscopy. 相似文献