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A density functional study on some cyclic N_(10) isomers

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Defence technology（防务技术） 2019年第2期15卷 154-161页

作者： Lemi türker Middle East technical University Department of Chemistry üniversiteler

Polynitrogen compounds, comprising only nitrogen atoms, are rare. they are considered as promising candidates of clean(green) high energy density materials because of their high energy content and their sole decomposition product is N_2. Extending the previous work which was on cyclic N_8 isomers, in this study some cyclic N_(10) isomers having 1-4 cycles are considered within the limitations of density functional theory at the levels of B3LYP/6-311++G(d,p) and B3LYP/cc-PVtZ. Some of the structures,including the monocyclic one, decompose by eliminating certain number of N_2 units while some remain intact. All the stable isomers(1-3, 6-8) investigated presently are highly endothermic that they are candidates for clean high energy materials. Certain quantum chemical properties, IR and UV-VIS spectra as well as the specific impulse values for the stable structures are reported.

关键词： Nitrogen Polynitrogen Density functional theory Isomers N10

Some remarks on the dynamical conformity of rock joints

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International Journal of Mining Science and technology 2018年第3期28卷 385-390页

作者： t.Ficker Faculty of Civil Engineering Brno University of Technology

A recently developed computerized method for assessing the rock joint coefficients is discussed. the performances of formerly introduced relative similarity indicators, along with the correlation coefficient, are subjected to critical analysis. these relative numerical indicators are replaced by two absolute indicators whose properties better describe surface textures of rock joints. the first absolute indicator results from the Fourier Matrix and evaluates wavy shapes of surfaces. the second absolute indicator quantifies the heights of surface reliefs, and is defined as the root mean square height of the surface outline. the behavior of the newly introduced numerical indicators are investigated by means of the deterministic periodic surface reliefs. the practical application of the new indicators is presented and the convenient performances of both the indicators are documented.

关键词： Rock joints Shear strength Joint rock coefficients Numerical indicators Computerized assessment

Exactness of penalization for exact minimax penalty function method in nonconvex programming

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Applied Mathematics and Mechanics(English Edition) 2015年第4期36卷 541-556页

作者： t.ANtCZAK Faculty of Mathematics and Computer Science University of Lódz

the exact minimax penalty function method is used to solve a noncon- vex differentiable optimization problem with both inequality and equality constraints. the conditions for exactness of the penalization for the exact minimax penalty function method are established by assuming that the functions constituting the considered con- strained optimization problem are invex with respect to the same function η （with the exception of those equality constraints for which the associated Lagrange multipliers are negative these functions should be assumed to be incave with respect to η）. thus, a threshold of the penalty parameter is given such that, for all penalty parameters exceeding this threshold, equivalence holds between the set of optimal solutions in the considered constrained optimization problem and the set of minimizer in its associated penalized problem with an exact minimax penalty function. It is shown that coercivity is not suf- ficient to prove the results.

关键词： exact minimax penalty function method minimax penalized optimizationproblem exactness of penalization of exact minimax penalty function invex function,incave function

Interaction of tAtB with Cu and Cu^(+1). A DFt study

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Defence technology（防务技术） 2019年第1期15卷 27-37页

作者： Lemi türker Middle East technical University Department of Chemistry

Symmetric triaminotrinitrobenzene known as tAtB decomposes in contact with some heavy metals,such as copper. Presently, tAtB and some of its important tautomers are subjected to B3LYP/6-31G(d,p) level of treatment. Some molecular orbital energies have been obtained and compared. then. interaction of these species with Cu and Cu^+ are investigated. Although tAtB has been found to be affected little by either Cu or Cu^+, undergoing only some bond length changes and/or distortions, the resonance-assisted tautomers having one to three aci groups decompose by the influence of Cu atom. In each case, only one N-OH bond rupture occurs.

关键词： triaminitrinitrobenzene tAtB tautomerism Copper DFt Pull-push

A DFt study on tNGU isomers and aluminized cis-tNGU composites

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Defence technology（防务技术） 2018年第2期14卷 109-118页

作者： Lemi trker Middle East technical University Department of Chemistryniversiteler

Cis-and trans-1,3,4,6-tetranitroglycouril(tNGU, Sorguyl) have been considered for density functional treatment at the levels of B3LYP/6-31 G(d,p) and B3LYP/cc-PVDZ. Cis-tNGU has been found to be more stable than its trans isomer. then, mono and dialuminized(cis-tNGU + Al and cis-tNGU+2Al) have been subjected to theoretical treatment at the level of B3LYP/6-31 + G(d). the spin states of the aluminized cis-tNGU composites have been considered as well. Although, cis-tNGU + Al(doublet) is found to be structurally stable, cis-tNGU+2Al singlet and triplet composites undergo certain bond *** and some quantum chemical properties, IR-UV spectra etc. have been presented.

关键词： tNGU Sorguyl Explosives Aluminized explosives DFt calculations

Electrically pumped metallic and plasmonic nanolasers

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Chinese Physics B 2018年第11期27卷 158-166页

作者： Martin t Hill School of Electrical Electronic and Computer Engineering The University of Western Australia

In recent years, there have been a significant number of demonstrations of small metallic and plasmonic lasers. the vast majority of these demonstrations have been for optically pumped devices. Electrically pumped devices are advantageous for applications and could demonstrate concepts not amenable for optical pumping. However, there have been relatively few demonstrations of electrically pumped small metal cavity lasers. this lack of results is due to the following reasons： there are limited types of electrically pumped gain media available; there is a significantly greater level of complexity required in the fabrication of electrically pumped devices; finally, the required components for electrical pumping restrict cavity design options and furthermore make it intrinsically more difficult to achieve lasing. this review looks at the motivation for electrically pumped nanolasers, the key issues that need addressing for them to be realized, the results that have been achieved so far including devices where lasing has not been achieved, and potential new directions that could be pursued.

关键词： semiconductor lasers laser diode microcavity and microdisk laser integrated optics

Characterization of mixing in an optimized designed t–t mixer with cylindrical elements

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Chinese Journal of Chemical Engineering 2019年第10期27卷 2337-2351页

作者： t.Manoj Dundi V.R.K.Raju V.P.Chandramohan Mechanical Engineering Department National Institute of TechnologyWarangalTelangana StateIndia

Passive micromixers are preferred over active mixers for many microfluidic applications due to their relative ease in integration into complex systems and operational *** also incur very low cost of ***,the degree of mixing is comparatively low in passive mixers than active mixers due to the absence of disturbance in the flow by external forces and the inherent laminar nature of microchannel *** designs of complex channel structures and three-dimensional geometries have been investigated in the past to obtain an efficient mixing in passive *** the studies on mixing enhancement with simple planar geometries of passive mixers have been few and *** present work aims to investigate the possibility of mixing enhancement by employing simple planar type designs,such as t-mixer and t–t mixer with cylindrical elements placed in the mixing *** mixing performance has been evaluated in the Reynolds number range of 6 *** results have shown that t–t mixer with cylindrical elements performed significantly well and obtained very good mixing quality over basic t-mixer for the entire range of Reynolds number(6 to 700).the device has also shown better mixing as compared to basic t–t mixer and t-mixer with cylindrical elements.A larger pair of vortices formed in the stagnation area due to the presence of a cylindrical element in the *** elements downstream caused significant enhancement in mixing due to splitting and recombining *** size of the cylindrical element in the t–t mixer has been optimized to obtain better mixing performance of the *** improvement in mixing quality by t–t mixer with cylindrical elements has been obtained at the expense of small rise in pressure drop as compared to other passive designs considered in this ***,the current design of t–t mixer with cylindrical elements can act as an effective and simple passive mixing device for various mi

关键词： CFD-simulation Cylindrical elements Micromixers Mixing quality Obstructions t–t-mixer

MHD UNStEADY FLOWS DUE tO NON—COAXIAL ROtAtIONS OF A DISK AND A FLUID At INFINItY

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Acta Mechanica Sinica 2003年第3期19卷 235-240页

作者： t.HAYAt IslamicInternationalEngineeringCollegec/oHeadOfficeIIMC OldSupremeCourtBuilding274PeshawarroadTheMallRawalpindiCanntPakistan

Exact analytical solution for flows of an electrically conducting fluid over an infinite oscillatory disk in the presence of a uniform transverse magnetic field is constructed. Both the disk and the fluid are in a state of non-coaxial rotation. Such a flow model has a great significance not only due to its own theoretical interest, but also due to applications to geophysics and engineering. the resulting initial value problem has been solved analytically by applying the Laplace transform technique and the explicit expressions for the velocity for steady and unsteady cases have been established. the analysis of the obtained results shows that the flow field is appreciably influenced by the applied magnetic field, the frequency and rotation parameters.

关键词： general periodic oscillation non-coaxial rotation magnetohydrodynamic flow Laplace transform

Nonequilibrium behavior of the kinetic metamagnetic spin-5/2 Blume–Capel model

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Chinese Physics B 2014年第7期23卷 350-359页

作者： müt temizer Department of Physics Bozok University

the dynamic magnetic behavior of the kinetic metamagnetic spin-5/2 Blume-Capel model is examined, within a mean-field approach, under a time-dependent oscillating magnetic field. to describe the kinetics of the system, Glauber- type stochastic dynamics has been utilized. the mean-field dynamic equations of the model are obtained from the Master equation. Firstly, these dynamic equations are solved to find the phases in the system. then, the dynamic phase transition temperatures are obtained by investigating the thermal behavior of dynamic sublattice magnetizations. Moreover, from this investigation, the nature of the phase transitions （first- or second-order） is characterized. Finally, the dynamic phase diagrams are plotted in five different planes. It is found that the dynamic phase diagrams contain the paramagnetic （P）, antiferromagnetic （AF5/2, AF3/2, AF1/2） phases and five different mixed phases. the phase diagrams also display many dynamic critical points, such as tricritical point, triple point, quadruple point, double critical end point and separating point.

关键词： metamagnetism spin-5/2 Blume-Capel model dynamic phase transitions dynamic phase dia-grams Glauber-type stochastic dynamics