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61.
M. S. Rahman Khan 《Applied Physics A: Materials Science & Processing》1984,35(4):263-265
The resistivity of thin films (80–200 Å) of ErH2 increases sharply when heated for 2 h at 300 °C in vacuum in the presence of hydrogen gas at 10–2 Torr. This confirms that the films, originally metallic conductor, have become converted to semiconducting ErH3 which is in conformity with the structural studies. The negative values of TCR also indicate the semiconducting nature of the hydrogen treated films. Activation energies of the films have been evaluated. 相似文献
62.
K. Sistemich W. -D. Lauppe T. A. Khan H. Lawin H. A. Selič J. P. Bocquet E. Monnand F. Schussler 《Zeitschrift für Physik A Hadrons and Nuclei》1978,285(3):305-313
Nuclear spectroscopy studies of 51 133 Sb82 have been performed at the recoil fission product separators JOSEF and LOHENGRIN. A tentative level scheme has been established for this nucleus with one proton in addition to the doubly closed shell core132Sn. Two isomeric states with half-lives of 3 and 16 μs have been found at excitation energies of >4300 keV and 4526 keV, respectively. Lower limits of 15/2 are deduced for the spins of these levels. The h11/2 proton state is suggested at 2792 keV in agreement with the systematics of the lighter Z=51 isotopes and the heavier N=82 isotones. Several states have been observed between 4300 and 4600 keV which are probably due to the coupling of the single proton to core-excited states which have energies between 4000 and 4800 keV. 相似文献
63.
Ali Raza Hala A. Hejazi Sami Ullah Khan M. Ijaz Khan Kamel Smida Iskander Tlili 《印度化学会志》2022,99(7):100568
In this investigation, a mixed convective nanoparticles fluid flow over an inclined plate is deliberated. The effects of slip boundary wall and magnetic field are also considered. The dimensionless governing system for the considered problem is attained by implementing recent definitions of fractional derivatives (FD). The generalized solution is obtained through the Laplace Transformation Scheme (LTS) for the momentum and thermal expressions. To improve the novelty and to demonstrate some more physical perception of the stated research work, some remarkable special cases of velocity distribution through CF and AB-fractional derivative concept are addressed, whose daily life implication is well known in the existing literature. Moreover, to evaluate the physical interest of the stated problem, the outcomes of the obtained system graphical illustrations are made by utilizing MATHEMATICA. As a result, we concluded that the aluminium oxide nanoparticles show more decaying behavior as compared to titanium oxide nanoparticles for temperature and velocity profile. Furthermore, both fields i.e., momentum and thermal distributions are increased with the help of rising estimations parameter. Current results report novel applications in enhancement of heat transfer, thermal engineering, chemical processes, engineering and electronics devices, solar systems, extrusion processes, fission reactions etc. 相似文献
64.
7-Ethyl-10-hydroxycamptothecin (SN-38) is an active metabolite of Irinotecan (CPT-11), an anticancer pro-drug. To support clinical pharmacokinetic studies for liposome based formulation of SN-38 (LE-SN38) in cancer patients, a rapid, simple and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the quantification of total SN-38 in human plasma. Sample preparation was carried out by one-step protein precipitation using cold acetonitrile with 0.5% acetic acid (v/v). Camptothecin was used as an internal standard (IS). Chromatographic separation of SN-38 and IS was achieved using a Synergi Hydro-RP column (C(18), 50 x 2 mm, 4 micro m), with a gradient elution of acetonitrile and 0.1% acetic acid. After ionization in electrospray source (positive ions), the acquisition was performed in the multiple reactions monitoring mode. Quantitation was accomplished using the precursor-->product ion combinations of m/z 393.1-->349.2 for SN-38 and 349.1-->305.1 for IS. The quantification limit of 0.05 ng/mL was achieved by using much lower volume (0.2 mL) of plasma and in the presence of LE-SN38. The method was validated over the concentration range of 0.05-400 ng/mL. Accuracy was within +/-12% of nominal at all concentration levels. Inter-day and intra-day precisions expressed as percentage coefficient of variation (%CVs) for quality control (QC) samples were less than 14 and 5%, respectively. 相似文献
65.
Aggregation and dispersion characteristics of calcium oxalate monohydrate: effect of urinary species
Christmas KG Gower LB Khan SR El-Shall H 《Journal of colloid and interface science》2002,256(1):168-174
In this research, screening and central composite experimental designs are used to determine the effect of various factors on the aggregation and dispersion characteristics of previously grown calcium oxalate monohydrate (COM) crystals in artificial urinary environments of controlled variables. The variables examined are pH and calcium, oxalate, pyrophosphate, citrate, and protein concentrations in ultrapure water and artificial urine. Optical density measurements, particle size analysis, optical microscopy, AFM force measurements, and protein adsorption have been used to assess the state of aggregation and dispersion of the COM crystals and to elucidate the mechanisms involved in such a complex system. The data indicate that our model protein, mucin, acts as a dispersant. This is attributed to steric hindrance resulting from the adsorbed mucoprotein. Oxalate, however, promotes aggregation. Interesting interactions between protein and oxalate along with protein and citrate are observed. Such interactions (synergistic or antagonistic) are found to depend on the concentrations of these species. Surface responses for these interactions are presented and discussed in this paper. In summary, solution, surface, and interface chemistries interact in a complex manner in the physiological environment to either inhibit or promote aggregation, and an understanding of such interactions may help determine and control the factors affecting kidney stone formation. 相似文献
66.
〉2M(NCS)2M′(SCN)2〈 and [ML6][M′(SCN)4], (M = Co(II) and Ni(II), M′ = Zn(II), Cd(II) and Hg(II) and L = aniline(ani), p-toluidine(tol), pyridine(py), nicotinamide(nia), 2,2′-bipyridine(bipy) and 4-aminopyridine (apy)) have been prepared and characterized. Their structure have been proposed on the basis of molar conductance, magnetic moment, group theoretical calculations, ligand field parameters, infrared and electronic spectral studies. The proposed structures have also been supported by quantitative values of softness ?\documentclass{article}\pagestyle{empty}\begin{document}$ {\rm E}_{\rm n}^{_ + ^ +},{\rm E}_{\rm m}^{_{\rm +}^{\rm +}} $\end{document}”?,. Total softness of M and M′ and their difference \documentclass{article}\pagestyle{empty}\begin{document}$ \Delta {\rm TE}_{\rm n}^{_ + ^ +} \left({{\rm M} - {\rm M}'} \right) $\end{document} have also been derived by the following equations and related to the structure of the complexes. . 相似文献
67.
Kamel Guedri Tahmoor Bashir A. Abbasi Waseh Farooq Sami Ullah Khan M. Ijaz Khan Mohammed Jameel Ahmed M. Galal 《印度化学会志》2022,99(9):100614
The electroosmotic peristaltic flow of modified hybrid nanofluid in presence of entropy generation has been presented in this thermal model. The Hall impact and thermal radiation with help of nonlinear relations has also been used to modify the analysis. The assumed flow is considered due to a non-uniform trapped channel. The properties of modified hybrid nanofluid model are focused with interaction of three distinct types of nanoparticles namely copper (, silver () and aluminum oxide ( The mathematical modeling and significances of entropy generation and Bejan number are identified. With certain flow assumptions, the governing equations are attained for optimized peristaltic electroosmotic problem. Widely used assumptions of long wave length and low Reynolds number reduced the governing equations in ordinary differential equations. The ND solver is flowed for the solution process. The physical significant of results is observed by assigning the numerical values to parameters. 相似文献
68.
The effects of Brij 35 micelles, CTABr micelles, and mixed Brij 35–CTABr micelles on the acid–base behavior of phenyl salicylate (PST) have been studied in aqueous solution containing 2% v/v acetonitrile. The apparent pKb (pKappb) of PST is decreased by 1.5 pK units with the increase in [Brij 35] from 0 to 0.02 M which is attributed to micellar medium effect. The values of pKappb remain almost independent of [CTABr] within its range 0.01–0.03 M. The increase in [CTABr] from 0 to 0.03 M in aqueous solution containing 0.02 M Brij 35 has not resulted in a change in pKappb. This shows that the characeristic structural features of nonionic Brij 35 micelles remain essentially unchanged on addition of CTABr under the present experimental conditions. 相似文献
69.
Kabir-ud-DinEmail author S.?M.?Shakeel?Iqubal Zaheer?Khan 《Colloid and polymer science》2005,284(3):276-283
Kinetics of the redox reaction between colloidal MnO2 and glycolic acid have been studied spectrophotometrically by monitoring the decay in the absorbance of colloidal MnO2 in absence and presence of surfactants. Anionic sodium dodecyl sulfate has no effect, non-ionic Triton X-100 catalyzed the reaction and experiments were not possible in presence of cationic cetyltrimethylammonium bromide due to the precipitation of MnO2.The reaction followed the same type of kinetic behavior, i.e., fractional-, first- and fractional-order dependencies, respectively, in [glycolic acid], [MnO2] and [H+ ] in both the media. Effects of gum arabic and manganese(II) have also been studied and discussed. Mechanisms in accordance with the experimental data are proposed for the reaction. 相似文献
70.
H. R. Khan K. Lüders Ch. J. Raub G. Roth 《Zeitschrift für Physik B Condensed Matter》1980,38(1):27-33
Superconductivity, structure and electrical resistance behaviour of -phase alloys of Nb–Rh and Ta–Rh are investigated. The Ta–Rh alloys do not become superconducting above 1.2 K. The
andH
c2
(0) values of a homogeneous alloy with the composition Nb65.2Rh34.8 are 2.95 K, 13.9 kG/K and 23 kG, respectively, whereas for an inhomogeneous alloy with the composition Nb63.7Rh36.3 these values are 4.24 K, 5.5 kG/K and 14 kG, respectively. Splat quenching results in a substantial increase in the
andH
c2
(0) values of the Rh-rich sample. Annealing (900°C, 100 h) of the Rh-rich sample leads only to small changes in the superconducting properties but a small amount of Nb–Rh solid solution has been formed. The electrical resistance of Nb65.2Rh34.8 decreases with decreasing temperature and varies asT
0.5 between 150 and 240 K and asT between 60 and 140 K. For Ta70.0Rh30.0 the temperature coefficient changes to negative values below 170K. values are calculated for Nb–Rh using McMillan's formula. An estimatedT
c
value of Ta–Rh is 0.2 K. TheH
c2
(0) values of Nb–Rh are in good agreement with the theoreticalH
c
2**
(0) values.Dedicated to Prof. Dr. W. Buckel on the occasion of his 60th birthday 相似文献