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491.
Alexander JP Bebek C Berkelman K Bloom K Browder TE Cassel DG Cho HA Coffman DM Crowcroft DS Drell PS Dumas D Ehrlich R Gaidarev P Garcia-Sciveres M Geiser B Gittelman B Gray SW Hartill DL Heltsley BK Henderson S Jones CD Jones SL Kandaswamy J Katayama N Kim PC Kreinick DL Ludwig GS Masui J Mevissen J Mistry NB Ng CR Nordberg E Patterson JR Peterson D Riley D Salman S Sapper M Würthwein F Avery P Freyberger A Rodriguez J Yang S Yelton J Cinabro D Liu T Saulnier M Wilson R Yamamoto H Bergfeld T 《Physical review letters》1995,74(16):3113-3117
492.
493.
The chromatic dispersion for conventional and Er-doped fibers using the refractive index approximation is examined. A first, analytical method for investigation of dispersion in step index triple clad optical fiber is used. To design of zero-dispersion shifted fiber for optical communication purpose manipulation of the refractive index and radius of the core are considered. We show that in presence of the Si-NC-Er ions, zero-dispersion wavelength is displaced and the dispersion quantity is increased. In this work, we try to optimize system parameters to obtain minimum dispersion and dispersion shifted fiber with control of the doping levels of Er ions and Si-NC as well as doping profiles. For especial case, we assumed the Gaussian inhomogeneous core refractive index for zero-dispersion wavelength and dispersion managements. 相似文献
494.
A. M. Gashimov K. Z. Nuriev K. B. Gurbanov A. Manuchar Salman Z. K. Nurubeyli T. K. Nurubeyli 《Technical Physics》2009,54(8):1185-1189
From experimental data for the yield of differently ionized ions at laser mass spectrometry, the dependence of the charge
composition of the ions on the laser radiation density is found for a number of metals. It is established that the amount
of multiply charged ions predominates over low-charged ones when the radiation density grows. An explanation is given for
the fact that singly charged ions prevail over multiply charged ones at the end of laser-induced plasma spread. The influence
of recombination on the ion distribution in the mass spectrum is estimated. 相似文献
495.
Shahid Adeel Khalid Mahmood Zia Muhammad Abdullah Mahwish Salman Mohammad Zuber 《Natural product research》2019,33(14):2060-2072
Natural products with therapeutic nature are nowadays warmly welcomed in textiles. Current study is concerned with isolation of tannin from neem bark (Azadirachta indica) and its application onto silk fabric. For improvement in shades, chemical & bio-mordants have been employed at optimal dyeing conditions. It is found that methanolic extract of pH 5 obtained 8 g dye powder after US Treatment for 30 min has given high color strength if used to dye irradiated silk for 65 min at 75 °C. Bio-mordanting using herbal plants has improved the color characteristics as compared to chemical mordants used. ISO standards for color fastness reveal that herbal based bio-mordants have improved the rating from good to excellent as compared to chemical mordants used. It is concluded that US treatment has not only isolate the colorant for neem bark under mild condition but also given excellent characteristic using bio mordants onto silk fabrics. 相似文献
496.
This article computes effect of uniform magnetic field on nanofluid flow filling porous medium inside parallel sheets. Darcy's law is used to characterize porous medium. Flow is caused by stretching of the lower sheet. The governing systems are computed using Finite difference technique. This scheme is used due to its more general and powerful nature to solve nonlinear problems. Results are obtained and discussed graphically. Nusselt number, skin friction, streamlines,velocity and temperature are emphasized. 相似文献
497.
This paper presents a canonical Hamiltonian model of liquid sloshing for the container coupled with spacecraft. Elliptical shape of rigid body is considered as spacecraft structure. Hamiltonian system is an important form of mechanical system. It mostly used to stabilize the potential shaping of dynamical system. Free surface movement of liquid inside the container is called sloshing. If there is uncontrolled resonance between the motion of tank and liquid-frequency inside the tank then such sloshing can be a reason of attitude disturbance or structural damage of spacecraft. Equivalent mechanical model of simple pendulum or mass attached with spring for sloshing is used by many researchers. Mass attached with spring is used as an equivalent model of sloshing to derive the mathematical equations in terms of Hamiltonian model. Analytical method of Lyapunov function with Casimir energy function is used to find the stability for spacecraft dynamics. Vertical axial rotation is taken as the major axial steady rotation for the moving rigid body. 相似文献
498.
Murtaza Saleem Saadat A. Siddiqi Shahid Atiq M. Sabieh Anwar Saira Riaz 《化学物理学报(中文版)》2010,23(4):469-472
Mn doped ZnO nano-crystallites were synthesized by state of the art sol-gel derived auto-combustion technique. As-burnt powder was investigated with different characterization techniques to explore the properties of Mn doped ZnO dilute magnetic semiconductor. X-ray diffraction measurements indicate that Mn doped ZnO retain wurtzite type hexagonal crystal structure like ZnO. Compositional and morphological studies were carried out by energy dispersive X-ray analysis and scanning electron microscopy, respectively. Tempera-ture dependent resistivity of the sample exhibited the semiconducting behavior of the DMS material. Room temperature magnetic properties determined by vibrating sample magne-tometer, revealed the presence of ferromagnetic and diamagnetic contributions in Mn doped ZnO. 相似文献
499.
Masood Parvez M. Saeed Arayne Najma Sultana Ahsan Zamir Siddiqi 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):910-912
The crystal structure of 4‐(3‐carboxy‐1‐ethyl‐6‐fluoro‐1,4‐dihydro‐4‐oxo‐7‐quinolyl)‐1‐methylpiperazinium methanesulfonate 0.10‐hydrate, C17H21FN3O3+·CH3O3S?·0.10H2O, contains pefloxacinium cations, methanesulfonate anions and a partially occupied water of solvation. The quinoline ring system in the cation is essentially planar. The anions lie parallel to each other about inversion centers. The structure is stabilized by strong hydrogen bonds involving the terminal piperazinyl‐N atom of the cation and an O atom of the anion [N?O 2.739 (2) Å], and a strong intramolecular hydrogen bond between carbonyl and carboxyl groups [O?O 2.523 (2) Å]. 相似文献
500.
Majid Monemzadeh Mehdi Dehghani Salman Abarghouei Nejad 《International Journal of Theoretical Physics》2017,56(6):1793-1806
We construct a new model for relativistic particle on the noncommutative plane, using the symplectic formalism of constrained systems. We suggest a shortcut approach to construct the gauged Lagrangian, using the Poisson algebra of constraints, without calculating the whole procedure of symplectic formalism. We also propose an approach for the systems, in which the symplectic formalism is not applicable, due to the truncation of production of secondary constraints at the first level. After gauging the model, we obtain the corresponding generators of gauge transformations of the physical system. Finally, by extracting the Poisson structure of all constraints, we show the effect of gauging on the canonical structure of the phase spaces of both primary and gauged models. 相似文献