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排序方式: 共有923条查询结果,搜索用时 31 毫秒
821.
K. K. Nandi S. M. K. Alam B. Bhattacharjee J. Evans 《General Relativity and Gravitation》1998,30(6):877-885
It is argued that the Schwarzschild black hole solution follows as a unique limit of the Brans-Dicke Class I solutions, provided the correct iterated limit is taken. Such a uniqueness is essential for the validity of a recent version of the no-hair conjecture. A non-trivial modification to this version is proposed in order to exclude Brans-Dicke Class IV solutions which appear to represent scalar hair black holes in general. 相似文献
822.
B.M. Ikramul Haque M.S. Alam Md. Majedur Rahman 《Journal of the Egyptian Mathematical Society》2013,21(2):142-147
The modified solutions of some nonlinear oscillators have been obtained based on the classical iteration procedure. In this article we have used the Fourier series and utilized all of its terms (sometimes approximately) in each iterative step. The third and fourth approximate frequencies of different nonlinear problems show good agreement with the exact values. 相似文献
823.
Teppei Yoshioka Tomonari Ogata Alam Md Zahangir Takamasa Nonaka Seiji Kurihara Corresponding author 《Liquid crystals》2013,40(1):15-19
This paper describes the discontinuous change in the helical pitch of a cholesteric liquid crystal (ChLC) by means of the photoisomerization of chiral azobenzene molecules under homogenous alignment conditions. A mixture of E44, R811 and Azo was prepared in the ratio 68/28/4, respectively. R811 and Azo have opposite twisting abilities such that they induce right- and left-handed helices, respectively when added to E44. The mixture was injected into a glass cell having a 2 or 5?µm cell gap, and treated for homogeneous molecular orientation. The wavelength of selective reflection from the ChLC was shifted to shorter wavelengths by the trans-cis photoisomerization of Azo. The change in the helical pitch was not only discontinuous, but also dependent on the cell thickness. The discontinuous change in the helical pitch was estimated to be almost the same as the half turn of the helical pitch in each cell gap, and was dependent on the number of helical half pitches in the glass cell. The homogeneous alignment condition affects the photochemical change in the helical structure of the ChLC system. 相似文献
824.
825.
Bowcock T Kinoshita K Pipkin FM Procario M Wilson R Wolinski J Xiao D Jawahery A Park CH Poling R Fulton R Haas P Hempstead M Jensen T Johnson DR Kagan H Kass R Morrow F Whitmore J Baringer P McIlwain RL Miller DH Ng CR Shibata EI Yao WM Alam MS Chen D Katayama N Kim IJ Li WC Lou XC Sun CR Tanikella V Bortoletto D Goldberg M Horwitz N Lubrano P Mestayer MD Moneti GC Sharma V Shipsey IP Skwarnicki T Csorna SE Letson T Brock IC Ferguson T Artuso M Bebek C Berkelman K Blucher E Byrd J Cassel DG 《Physical review letters》1989,62(11):1240-1242
826.
C. David Gutsche Iftikhar Alam Muzaffar Iqbal Thomas Mangiafico Kye Chun Nam Janet Rogers Keat Aun See 《Journal of inclusion phenomena and macrocyclic chemistry》1989,7(1):61-72
Several facets of calixarene chemistry have been investigated including the mechanism of their formation by the base-induced condensation of phenols and formaldehyde, procedures for introducing functional groups onto the upper rim and lower rim of calixarenes, the conformational behavior of calixarene oxyanions, the formation of complexes in aqueous and nonaqueous systems, and the application of calixarenes as catalysts. 相似文献
827.
The kinetics of the reactions of hydroxyl radicals with aliphatic alcohols in aqueous solution were studied using pulse radiolysis. Based on the optical absorption observed in the UV region, the rate constants for the reaction of hydroxyl radicals with methanol, ethanol, 2-propanol and tert-butyl alcohol were determined to be 9.0×108, 2.2×109, 2.0×109 and 6.2×108 dm3 mol−1 s−1, respectively. The values obtained here by direct observation of the alcohol radicals basically confirm the values which were earlier determined indirectly by competition. 相似文献
828.
Baringer P McIlwain RL Miller DH Shibata EI Behrends S Guida JM Guida JA Morrow F Poling R Thorndike EH Tipton P Alam MS Katayama N Kim IJ Li WC Lou XC Sun CR Tanikella V Bortoletto D Goldberg M Holmes R Horwitz N Jawahery A Lubrano P Moneti GC Sharma V Shipsey IP Thoma P Csorna SE Letson T Mestayer MD Panvini RS Word GB Bean A Bobbink GJ Brock IC Engler A Ferguson T Kraemer RW Rippich C Vogel H Bebek C Berkelman K Blucher E Cassel DG Copie T DeSalvo R DeWire JW Ehrlich R Galik RS Gilchriese MG 《Physical review letters》1987,59(18):1993-1996
829.
Bowcock T Giles RT Hassard J Kinoshita K Pipkin FM Wilson R Gentile T Haas P Hempstead M Jensen T Kagan H Kass R Behrends S Guida JM Guida JA Morrow F Poling R Rosenfeld C Thorndike EH Tipton P Green J Sannes F Stone R Alam MS Katayama N Kim IJ Sun CR Tanikella V Bortoletto D Chen A Garren L Goldberg M Horwitz N Jawahery A Lubrano P Moneti GC Csorna SE Mestayer MD Panvini RS Word GB Bean A Bobbink GJ Brock I Engler A Ferguson T Kraemer R Rippich C Sutton R Vogel H Bebek C Berkelman K Blucher E 《Physical review letters》1986,56(25):2676-2679
830.
Fulton R Hempstead M Jensen T Johnson DR Kagan H Kass R Morrow F Whitmore J Chen W Dominick J McIlwain RL Miller DH Ng CR Shibata EI Yao W Sparks K Thorndike EH Alam MS Katayama N Kim IJ Li WC Lou XC Sun CR Bortoletto D Goldberg M Horwitz N Lubrano P Mestayer MD Moneti GC Sharma V Shipsey IP Skwarnicki T Csorna SE Letson T Brock IC Ferguson T Vogel H Alexander J Artuso M Bebek C Byrd J Berkelman K Blucher E Cassel DG Cheu E Coffman DM Copie T Crawford G DeWire JW Drell PS Ehrlich R Galik RS 《Physical review D: Particles and fields》1990,41(5):1401-1409