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101.
Ambar Chowdhury 《Archive for Mathematical Logic》1995,34(1):21-31
Research supported by the NSERC of Canada 相似文献
102.
We analyze the Zakharov-Shabat-type inverse problem when the reflection coefficient contains poles in the eigenvalue plane, as an extension of the earlier work by Atkinson in the case of the Schrödinger problem. It is demonstrated that due to the mutual influence of such a pole and the usual bound-state pole, a discontinuous solitary wave profile is generated. Furthermore, we also examine the form of the nonlinear field only due to the pole of the reflection coefficient. A different approach is necessary to convert the GLM equation into a purely differential one for its solution. 相似文献
103.
Supriya Mukherjee A. Ghose Choudhury A. Roy Chowdhury 《International Journal of Theoretical Physics》2006,45(4):820-834
We investigate the relation between the local variables of a discrete integrable lattice system and the corresponding separation variables, derived from the associated spectral curve. In particular, we have shown how the inverse transformation from the separation variables to the discrete lattice variables may be factorized as a sequence of canonical transformations. 相似文献
104.
C. C. Lee R. L. Chowdhury A. Pirko R. G. Sutherland 《Journal of organometallic chemistry》1986,310(3):391-400
Di-η5-cyclopentadienyliron complexed dications of 9,10-dihydroanthracene, xanthene, thioxanthene and diphenylmethane derived from ligand exchange reactions but without their prior isolation were oxidized with KMnO4 to give, respectively, the dications of anthraquinone, xanthone, thioxanthone and benzophenone, isolated as their dihexafluorophosphate salts. Cyclopentadienyliron complexes of arenes containing a sulfide function were oxidized by m-chloroperbenzoic acid to the corresponding complexed sulfones, and sulfones prepared in this way include the hexafluorophosphate salt of the η6-p-tolysulfonylbenzene, thioxanthene-10,10-dioxide, 9,9-dimethylthioxanthene-10,10-dioxide or dibenzothiophene-9,9-dioxide-η5-cyclopentadienyliron cation. 相似文献
105.
Galerkin representations for the displacement vector, polarization vector and the potential field are obtained by elementary matrix inversions of the equations of equilibrium. Matrices of fundamental solutions of an infinite elastic dielectric continuum subjected to a concentrated body force, an electric force, and a charge density, are constructed. Theorems are proved on the discontinuity of double layer potentials and R, M, M operators of single layer potentials. By means of these theorems, the solution of the two basic boundary value problems has been reduced to the solution of a system of seven singular integral equations. 相似文献
106.
Representations of Galerkin type are obtained for the displacement vector, polarization vector and the potential fields in the static plane theory of elastic dielectrics using the method of associated matrices. Fundamental matrix solutions of an infinite elastic dielectric plane subjected to a concentrated body force, electric force and charge density are derived from the singular solutions of harmonic, biharmonic and Helmholtz equations. Using boundary operatorsY, Z, M, the fundamental matrix solutions, and Betti's formulae, a matrix (x, y) is constructed and an integral representation for (u
1,u
2,P
1,P
2, ) is obtained. Discontinuity theorems are stated for the double layer potential andQ operator of the single layer potential. By means of these theorems, the solutions of interior and exterior boundary value problems are reduced to the solution of a system of five singular integral equations. The index of one of the systems is shown to be zero and it is concluded that Fredholm theorems and its alternatives hold.
Zusammenfassung Durch Anwendung der Assoziativ-Matrizen-Methode werden Galerkinische Darstellungen für den Verschiebungsvektor, den Polarisierungsvektor und die potentiellen Prüffelder einer statischen ebenen Theorie des elastischen Dielektrikums entwickelt. Von den singulären Lösungen der harmonischen, biharmonischen und Helmholtz-Gleichungen werden grundlegende Matrizenlösungen für das unendliche, ebene und elastische Dielektrikum, das durch konzentrierte Raumkräfte, elektrische Kräfte und Ladungsdichte beansprucht wird, abgeleitet. Unter Verwendung der Randwert-OperatorenY, Z, M, der grundlegenden Matrizen-Lösungen und Betti's Formel, wird eine Spezial-Matrize (x, y) konstruiert und eine Integraldarstellung für (u 1,u 2,P 1,P 2, ) erhalten. Unstetigkeitssätze werden für das Doppelschicht-Potential und denQ-Operator eines einschichtigen Potentials angeführt. Durch Anwendung dieser Sätze werden die Lösungen der inneren und äusseren Grenzwertprobleme zur Lösung eines Systems von fünf singulären Integralgleichungen reduziert. Der Index eines der Systeme wird als Null bewiesen und es wird die Schlussfolgerung gezogen, dass der Fredholmsche Satz und seine Alternativen fur diese Theorie anwendbar sind.相似文献
107.
Yuanzhong Yang Reinhard I. BoysenJamil Chowdhury Asif AlamMilton T.W. Hearn 《Analytica chimica acta》2015
In this study, the advantages of carrying out the analysis of peptides and tryptic digests of proteins under gradient elution conditions at pH 6.5 by reversed-phase liquid chromatography (RP-HPLC) and in-line electrospray ionisation mass spectrometry (ESI-MS) are documented. For these RP separations, a double endcapped, bidentate anchored n-octadecyl wide pore silica adsorbent was employed in a capillary column format. Compared to the corresponding analysis of the same peptides and protein tryptic digests using low pH elution conditions for their RP-HPLC separation, this alternative approach provides improved selectivity and more efficient separation of these analytes, thus allowing a more sensitive identification of proteins at different abundance levels, i.e. more tryptic peptides from the same protein could be confidently identified, enabling higher sequence coverage of the protein to be obtained. This approach was further evaluated with very complex tryptic digests derived from a human plasma protein sample using an online two-dimensional (2D) strong cation-exchange (SCX)-RP-HPLC-ESI-MS/MS system. Again, at pH 6.5, with mobile phases of different compositions, improved chromatographic selectivities were obtained, concomitant with more sensitive on-line electrospray ionisation tandem mass spectrometric (ESI-MS/MS) analysis. As a consequence, more plasma proteins could be confidently identified, highlighting the potential of these RP-HPLC methods with elution at pH 6.5 to extend further the scope of proteomic investigations. 相似文献
108.
109.
Mohammad Akbar Ali Aminul Huq Mirza Ray J. Butcher Arun K. Chowdhury 《Transition Metal Chemistry》2011,36(5):471-479
A new tridentate ONS ligand, H2L, has been synthesized by condensing thenoyltrifluoroacetone(4,4,4-trifluoro-1-(2-thienyl)-2,4butaneanedione) with S-benzyldithiocarbazate
and its structure determined by X-ray diffraction. In the solid state, the Schiff base exists as the ketoamine-thioketo tautomer
but in solution and in the presence of copper(II), it converts to the enol-thiol form and deprotonates to give copper(II)
complexes of formula, [CuL] and [CuLL1] (L = doubly deprotonated form of the ligand; L1 = py, bipy or phen] which have been characterized by magnetic, spectroscopic, and X-ray diffraction studies. An X-ray crystallographic
analysis shows that [CuL(py)] has a square-planar geometry with the ligand coordinated to the copper(II) center via the enolate
oxygen, the azomethinic nitrogen and the thiolate sulfur, the fourth coordination position being occupied by pyridine. The
[CuL(bipy)] complex is five-coordinate with a structure close to square-pyramidal in which the Schiff base acts as a doubly
deprotonated tridentate ONS ligand and bipy is bidentate. 相似文献
110.
Polypyrrole nanoparticles of desired structure have been synthesized through simple micelle technique. It is then grafted with functionalized silica gel to develop a novel organic-inorganic hybrid material. The role of dimethyl dichloro silane (coupling agent) in grafting is demonstrated. The nanoparticles are characterized by TEM, SEM and TGA. Grafting reactions are evaluated by spectral (FTIR) analysis and chemical test. The Cr(VI) binding behavior of the composite is studied in various pH of the medium. The selectivity in binding Cr(VI) is monitored. The metal ion adsorption capacity and surface area of the material are found to be 38 mg/g and 235 m2/g, respectively. 相似文献