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排序方式: 共有119条查询结果,搜索用时 15 毫秒
31.
Zagharide Zine EL ABIDINE 《数学物理学报(B辑英文版)》2014,(5):1404-1416
Let m be a positive integer and B be the unit ball of Rn(n ≥ 2). We investigate the existence, uniqueness and the asymptotic behavior of a positive continuous solution to the following semilinear polyharmonic boundary value problem(-△)mu = a1(x)uα1+ a2(x)uα2, lim|x|→1u(x)(1- |x|)m-1= 0,where α1, α2 ∈(-1, 1) and a1, a2 are two nonnegative measurable functions on B satisfying some appropriate assumptions related to Karamata regular variation theory. 相似文献
32.
A simple, sensitive and rapid spectrofluorometric method for determination of methocarbamol in pharmaceutical formulations
and spiked human plasma has been developed. The proposed method is based on the measurement of the native fluorescence of
methocarbamol in methanol at 313 nm after excitation at 277 nm. The relative fluorescence intensity-concentration plot was
rectilinear over the range of 0.05–2.0 μg/mL, with good correlation (r = 0.9999), limit of detection of 0.007 μg/ mL and a lower limit of quantification of 0.022 μg/ mL. The described method was
successfully applied for the determination of methocarbamol in its tablets without interference from co-formulated drugs,
such as aspirin, diclofenac, paracetamol and ibuprofen, The results obtained were in good agreement with those obtained using
the official method (USP 30).The high sensitivity of the method allowed the determination of the studied drug in spiked human
plasma with average percentage recovery of 99.42 ± 3.84. 相似文献
33.
The reaction of N-thiocarbamoylimidates 1 with methyl thioglycolate leads to the formation of 4-arylamino-5-methoxycarbonylthiazoles 2. The condensation of the same imidates 1 on ethyl bromoacetate, benzyl bromide and chloroacetonitrile provides the corresponding 2-arylaminothiazoles 4. 相似文献
34.
Simulation and Experimental Study for Degradation of Organic Dyes Using Dual pin‐to‐plate Corona Discharge Plasma reactors for Industrial Wastewater Treatment
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This work researches the possibility of increasing the dye removal efficiency from wastewater using nonthermal plasma. A study for the optimal air gap distance between dual pin and surface of Acid Blue 25 dye solution and thickness of ground plate is carried out using 3D‐EM simulator to find maximum electric field intensity at the tip of both pins. The consequences display that the best gap for corona discharge is approximately 5 mm using 15 kV source. In addition, the optimum plate thickness is 0.1 mm. These distance and thickness were mentioned are constant during the study of other factors. Dual pin‐to‐plate high‐voltage corona discharge plasma system is presented to investigation experimentally the gap distance, thickness of ground plate, initial dye concentration, pH solution and conductivity on the amount of Acid Blue 25 dye color removal efficiency from wastewater. There is a large consensus among the simulation and experimental work in the air gap and thickness of ground plate. Where the decolorization for air gap 5 mm is 95.74 at time 35 min compared with 91% and 17% for 1 mm and 20 mm gap distance respectively. Also, the discharge energy at each air gap are calculated. Measurement results for the impact of thickness of an Aluminum ground plate on color removal competence showed color removal efficiencies of 86.3%, 90.78% and 98.06%, after treatment time 15 min for thicknesses of 2, 0.5 and 0.1 mm respectively. The decolorization behavior utilizing dual pin‐to‐plate corona discharge plasma system display 82% pigment evacuation proficiency inside 11min. The complete decolorization was accomplished within 28min for distinctive examined introductory color focuses 5 ppm up to 100 ppm. Likewise, the impacts of conductivity by utilizing diverse salts as AlCl3, CaCl2, KCl and NaCl and with distinctive focuses have been explored. The rising of the solution conductivity leads to the reduction of decolorization efficiency. The decolorization efficiency and discharge energy are calculated at different concentration molarity for AlCl3, CaCl2, KCl and NaCl. It was observed that the presence of salts at the same concentration level substantially decreased the rate and the extent of decolorization. The results indicate that the optimum pH for the decolorization of Acid Blue 25 dye is in the range between 3 and 6. Furthermore the conductivity and discharge energy were measurement at each value of pH. Energy yield for decolorization and Electrical Energy per Order (EE/O) under different initial pH value were calculated. A kinetic model is used to define the performance of corona discharge system under different value of pH. The model of pseudo ‐zero, pseudo‐first order, and pseudo‐second order reactions kinetic are utilized to investigate the decolorization of Acid Blue 25 dye. The rate of degradation of Acid Blue 25 dye follows the pseudo‐first order kinetics in the dye concentration. Energy consumption requirements for decolorization was considered. The outcomes will be useful for designing the plasma treatment systems suitable for industrial wastewaters. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
35.
Manal M. Elshahawi Ahmed K. EL‐Ziaty Jehan M. Morsy Aly F. Aly 《Journal of heterocyclic chemistry》2016,53(5):1443-1448
A novel bis benzoxazin‐4‐one derivative has been synthesized and utilized to construct a new series of bis quinazolin‐4(3H)‐one derivatives via the reactions with different nitrogen nucleophiles namely, primary amines (ammonia, ethanolamine, and 4‐aminoantipyrine), secondary amines (morpholine and piperidine), diamine (o‐phenylenediamine), hydrazine hydrate, and hydroxylamine. The insecticidal efficacy of newly synthesized compounds was also studied. The structural features of the synthesized compounds were assigned by spectral analysis. 相似文献
36.
Muhammad Zahid Maria Lodhi Zulfiqar Ahmad Rehan Hamna Tayyab Talha Javed Rubab Shabbir Ahmed Mukhtar Ayman EL Sabagh Robert Adamski Mohamed I. Sakran Dorota Siuta 《Molecules (Basel, Switzerland)》2021,26(11)
The formation of new scaffolds to enhance healing magnitude is necessarily required in biomedical applications. Granulation tissue formation is a crucial stage of wound healing in which granulation tissue grows on the surface of a wound by the formation of connective tissue and blood vessels. In the present study, porous hydrogels were synthesized using chitosan incorporating latex of the Calotropis procera plant by using a freeze–thaw cycle to stimulate the formation of granulation tissue and angiogenesis in wound healing applications. Structural analysis through Fourier transform infrared (FTIR) spectroscopy confirmed the interaction between chitosan and Calotropis procera. Latex extract containing hydrogel showed slightly higher absorption than the control during water absorption analysis. Thermogravimetric analysis showed high thermal stability of the 60:40 combination of chitosan (CS) and Calotropis procera as compared to all other treatments and controls. A fabricated scaffold application on a chick chorioallantoic membrane (CAM) showed that all hydrogels containing latex extract resulted in a significant formation of blood vessels and regeneration of cells. Overall, the formation of connective tissues and blood capillaries and healing magnitude decreased in ascending order of concentration of extract. 相似文献
37.
B. EL Goundali M. Kaddami 《Fluid Phase Equilibria》2011,306(2):175-180
H2O + Ni(NO3)2 binary system were investigated in the temperature range from −25 °C to 55 °C. The solid-liquid equilibria of the ternary system H2O + Fe(NO3)3 + Ni(NO3)2 were studied using a synthetic method based on conductivity measurements. Tow isotherms were established at 0 °C and 30 °C, and the appearing stable solid phases are iron nitrate nonahydrate (Fe(NO3)3·9H2O), iron nitrate hexahydrate (Fe(NO3)3·6H2O), nickel nitrate hexahydrate (Ni(NO3)2·6H2O) and nickel nitrate tetrahydrate (Ni(NO3)2·4H2O). 相似文献
38.
Mn(II), Co(II), Ni(II), Cu(II), Pd(II) and Ru(III) complexes of Schiff bases derived from the condensation of sulfaguanidine with 2,4‐dihydroxy benzaldehyde ( HL1 ), 2‐hydroxy‐1‐naphthaldehyde ( HL2 ) and salicylaldehyde ( HL3 ) have been synthesized. The structures of the prepared metal complexes were proposed based on elemental analysis, molar conductance, thermal analysis (TGA, DSC and DTG), magnetic susceptibility measurements and spectroscopic techniques (IR, UV‐Vis, and ESR). In all complexes, the ligand bonds to the metal ion through the azomethine nitrogen and α‐hydroxy oxygen atoms. The structures of Pd(II) complex 8 and Ru(III) complex 9 were found to be polynuclear. Two kinds of stereochemical geometries; distorted tetrahedral and distorted square pyramidal, have been realized for the Cu(II) complexes based on the results of UV‐Vis, magnetic susceptibility and ESR spectra whereas octahedral geometry was predicted for Co(II), Mn(II) and Ru(III) complexes. Ni(II) complexes were predicted to be square planar and tetrahedral and Pd(II) complexes were found to be square planar. The antimicrobial activity of the ligands and their metal complexes was also investigated against the gram‐positive bacteria Staphylococcus aures and Bacillus subtilis and gram‐negative bacteria, Escherichia coli and Pesudomonas aeruginosa, by using the agar dilution method. Chloramphenicol was used as standard compound. The obtained data revealed that the metal complexes are more or less, active than the parent ligand and standard. The X‐ray crystal structure of HL3 has been also reported. 相似文献
39.
O. EL AKRAMINE W. A. LESTER JR X. KROKIDIS C. A. TAFT T. C. GUIMARAES A. C. PAVAO 《Molecular physics》2013,111(1-2):277-285
The chemisorption of CO on a Cr (110) surface is investigated using the quantum Monte Carlo method in the diffusion Monte Carlo (DMC) variant and a model Cr2CO cluster. The present results are consistent with the earlier ab initio HF study with this model that showed the tilted/near-parallel orientation as energetically favoured over the perpendicular arrangement. The DMC energy difference between the two orientations is larger (1.9 eV) than that computed in the previous study. The distribution and reorganization of electrons during CO adsorption on the model surface are analysed using the topological electron localization function method that yields electron populations, charge transfer and clear insight on the chemical bonding that occurs with CO adsorption and dissociation on the model surface. 相似文献
40.
40 absolute line wavenumbers in the 3v 3 band of 12C16O2 between 6927 cm?1 and 6989 cm?1 and 626 absolute line wavenumbers in the near infrared absorption spectrum of 12C2H2 between 7060 cm?1 and 9900 cm?1 have been measured using high resolution Fourier transform spectroscopy. The calibration of the CO2 line wavenumbers relied on heterodyne frequencies available in the v 1 + v 3 band of 12C2H2 near 6556 cm?1. The absolute uncertainty of the calibrated CO2 line wavenumbers is estimated to 0.000 08 cm?1. The acetylene spectra were calibrated using heterodyne frequencies available in the 2—0 band of 12C16O and the line wavenumbers obtained in the 3v 3 band of 12C16O2. The absolute uncertainty of the calibrated acetylene line wavenumbers is estimated to range from 0.0003 cm?1 to 0.006 cm?1 for strong to very weak isolated lines. Comparison with absolute line wavenumbers obtained independently at JPL in the 3v 3 band of 12C2H2 near 9649 cm?1, calibrated using absolute wavenumbers available in the 2—0 and 3—0 (near 6350 cm?1) bands of 12C16O, shows very good agreement. Also, the vibration—rotation constants for the observed upper vibrational states of 12C2H2 were determined, but without accounting for the perturbations affecting these states. 相似文献