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1.
H.?Mohseni?SadjadiEmail author M.?Alimohammadi 《General Relativity and Gravitation》2005,37(11):1809-1822
We obtain the electrostatic energy of two opposite charges near the horizon of stationary black holes in the massive Schwinger
model. Besides the confining aspects of the model, we discuss the Bekenstein entropy upper bound of a charged object using
the generalized second law. We show that despite the massless case, in the massive Schwinger model the entropy of the black
hole and consequently the Bekenstein bound are altered by the vacuum polarization. 相似文献
2.
Exactly solvable models through the generalized empty interval method,for multi-species interactions
A. Aghamohammadi M. Alimohammadi M. Khorrami 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,31(3):371-378
Multi-species reaction-diffusion systems, with nearest-neighbor interaction on a one-dimensional lattice are considered. Necessary
and sufficient constraints on the interaction rates are obtained, that guarantee the closedness of the time evolution equation
for E
n(t)'s, the expectation value of the product of certain linear combination of the number operators on n consecutive sites at time t. The constraints are solved for the single-species left-right-symmetric systems. Also, examples of multi-species system for
which the evolution equations of E
n(t)'s are closed, are given.
Received 25 September 2002 / Received in final form 3 December 2002 Published online 14 February 2003
RID="a"
ID="a"e-mail: mamwad@iasbs.ac.ir 相似文献
3.
M. Alimohammadi M. Khorrami 《The European Physical Journal C - Particles and Fields》2006,47(2):507-512
The large-N behavior of Yang–Mills and generalized Yang–Mills theories in the double-scaling limit is investigated. By the
double-scaling limit, it is meant that the area of the manifold on which the theory is defined, is itself a function of N.
It is shown that phase transitions of different orders occur, depending on the functional dependence of the area on N. The
finite-size scalings of the system are also investigated. Specifically, the dependence of the dominant representation on A,
for large but finite N is determined. 相似文献
4.
By using the path integral method, we calculate the Green functions of the field strength of Yang-Mills theories on arbitrary nonorientable surfaces in Schwinger-Fock gauge.We show that the non-gauge invariant correlators consist of a free part and an almost x-independent part. We also show that the gauge invariant n-point functions are those corresponding to the free part, as in the case of orientable surfaces. 相似文献
5.
Nezhad MR Alimohammadi M Tashkhourian J Razavian SM 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,71(1):199-203
An indirect colorimetric method is presented for detection of trace amounts of hydroquinone (1), catechol (2) and pyrogallol (3). The reduction of AuCl4(-) to Gold nanoparticles (Au-NPs) by these phenolic compounds in the presence of cetyltrimethylammonium chloride (CTAC) produced very intense surface plasmon resonance peak of Au-NPs. The plasmon absorbance of Au-NPs allows the quantitative colorimetric detection of the phenolic compounds. The calibration curves derived from the changes in absorbance at lambda = 568 nm were linear with concentration of hydroquinone, catechol and pyrogallol in the range of 7.0 x 10(-7) to 1.0 x 10(-4)M, 6.0 x 10(-6) to 2.0 x 10(-4)M and 6.0 x 10(-7) to 1.0 x 10(-4)M, respectively. The detection limits were 5.3 x 10(-7), 2.5 x 10(-6) and 3.2 x 10(-7)M for the hydroquinone, catechol and pyrogallol, respectively. The method was applied satisfactorily to the determination of phenolic compounds in water samples and pharmaceutical formulations. 相似文献
6.
The solventless microwave‐assisted synthesis of 2,4,5‐triaryl imidazoles from 1,2‐diphenylethandione or 2‐hydroxy‐1,2‐diphenylethanone in the presence of NH4OAc/NaHSO4 supported onto silica gel under microwave irradiation is reported. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:699–702, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20237 相似文献
7.
An Efficient and Selective Solid State Oxidation of Thiols to Disulfides with Quinolinium Fluorochromate on Silica Gel 总被引:1,自引:0,他引:1
Tajbakhsh Mahmood Mohammadpoor-Baltork Iraj Alimohammadi Kamal 《Monatshefte für Chemie / Chemical Monthly》2003,134(12):1571-1575
Summary. Various kinds of aliphatic (cyclic and acyclic), aromatic, and heterocyclic thiols are converted into the corresponding disulfides by quinolinium fluorochromate (QFC) on silica-gel in excellent yields. Selective oxidation of thiols in the presence of sulfides is also achieved under solid phase conditions. 相似文献
8.
Reaction of N-methyl-2-amino-4-nitroaniline ( 1 ) with lactic acid afforded 2-(1-hydroxyethyl)-1-methyl-5-nitrobenzimidazole ( 2 ). Oxidation of compound 2 with chromic acid in acetic acid gave 2-acetyl-1-methyl-5-nitrobenzimidazole ( 3 ). Reaction of compound 3 with substituted 2-aminobenzaldehyde ( 4 ) under basic conditions yielded substituted 2-(1-methyl-5-nitro-2-benzimidazolyl)quinolines ( 5 ). Condensation and cyclization of o-aminoacetophenone (or substituted o-aminobenzophenones) with compound 3 under acetic condition afforded compound 7 . Condensation and cyclization of compound 1 with indole-3-carboxaldehyde ( 11 ) in ethanol in the presence of excess nitrobenzene gave 3-(1-methyl-5-nitro-2-benzimidazolyl)indole ( 12 ). 相似文献
9.
M. Alimohammadi A. Shariati 《The European Physical Journal C - Particles and Fields》2001,21(1):193-196
Berry phase for a spin-1/2 particle moving in a flat space-time with torsion is investigated in the context of the Einstein–Cartan–Dirac
model. It is shown that if the torsion is due to a dense polarized background, then there is a Berry phase only if the fermion
is massless and its momentum is perpendicular to the direction of the background polarization. The order of magnitude of this
Berry phase is discussed in other theoretical frameworks.
Received: 12 February 2001 / Revised version: 2 May 2001 / Published online: 29 June 2001 相似文献
10.