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101.
40PbO–(10 ? x)PbF2–50 SiO2:xWO3 (where x = 1 to 7 mol%) glasses are prepared in the glass forming region. Spectroscopic studies (UV–Vis absorption, ESR, IR) are carried out for these glasses. Interesting changes are observed in the spectroscopic parameters of these glasses when the concentration of WO3 is changing in the glass matrix. Two absorption bands are observed around at 830 and 620 nm. ESR signal are measured at room temperature for these glasses, the strength of the signal is increased and hyperfine splitting is resolved with increasing the concentration of WO3 in the glass matrix. IR transmission gives valuable information about the nature of bonds in the glass matrix. The physical parameters along with spectroscopic parameters are measured. 相似文献
102.
We discuss many interesting and attractive features of a higher-dimensional cosmology with a static traversable wormhole dominated by a variable effective cosmological constant depending on the scale factor aft) as Aeffective =Ca^-2 + A0, where C and A0 are positive constants. 相似文献
103.
Reddy Vemulapati Hanuman Kumari Avula Krishna Reddy Guda Mallikarjuna Reddy Yellala Venkata Rami Garcia Jarem Raul Zyryanov Grigory V. Reddy Nemallapudi Bakthavatchala Rammohan Aluru 《Chemistry of Heterocyclic Compounds》2019,55(1):60-65
Chemistry of Heterocyclic Compounds - Environmentally benign one-pot multicomponent synthesis of different 1,4-dihydropyridine derivatives using montmorillonite K10 has been achieved. The... 相似文献
104.
Rami Ahmad El-Nabulsi 《理论物理通讯》2018,69(3):233-240
Recently,the notion of non-standard Lagrangians was discussed widely in literature in an attempt to explore the inverse variational problem of nonlinear differential equations.Different forms of non-standard Lagrangians were introduced in literature and have revealed nice mathematical and physical properties.One interesting form related to the inverse variational problem is the logarithmic Lagrangian,which has a number of motivating features related to the Li′enard-type and Emden nonlinear differential equations.Such types of Lagrangians lead to nonlinear dynamics based on non-standard Hamiltonians.In this communication,we show that some new dynamical properties are obtained in stellar dynamics if standard Lagrangians are replaced by Logarithmic Lagrangians and their corresponding non-standard Hamiltonians.One interesting consequence concerns the emergence of an extra pressure term,which is related to the gravitational field suggesting that gravitation may act as a pressure in a strong gravitational field.The case of the stellar halo of the Milky Way is considered. 相似文献
105.
Rami Ayoub Jamal Jilani Qais Jarrar Raad Alani Chrismawan Ardianto Khang Wen Goh Dalia Ali Said Moshawih 《Molecules (Basel, Switzerland)》2022,27(9)
2-(4-Chlorophenyl)-5-benzoxazoleacetic acid (CBA) and its ester, methyl-2-(4-chloro-phenyl)-5-benzoxazoleacetate (MCBA), were synthesized, and their structures were confirmed by 1HNMR, IR, and mass spectrophotometry. The anti-psoriatic activities of CBA and MCBA were tested using an imiquimod (IMQ)-induced psoriatic mouse model, in which mice were treated both topically (1% w/w) and orally (125 mg/kg) for 14 days. The erythema intensity, thickness, and desquamation of psoriasis were scored by calculating the psoriasis area severity index (PASI). The study also included the determination of histopathological alterations in the skin tissues of treated mice. Topical and oral administration of CBA and MCBA led to a reduction in erythema intensity, thickness, and desquamation, which was demonstrated by a significant decrease in the PASI value. In addition, skin tissues of mice treated with CBA and MCBA showed less evidence of psoriatic alterations, such as hyperkeratosis, parakeratosis, scale crust, edema, psoriasiform, and hyperplasia. After administration of either topical or oral dosing, the anti-psoriatic effects were found to be stronger in MCBA-treated than in CBA-treated mice. These effects were comparable to those produced by Clobetasol propionate, the reference drug. This drug discovery could be translated into a potential new drug for future clinical use in psoriasis treatment. 相似文献
106.
107.
The relative free energy difference (ΔΔGhyd) for the reversible addition of water to two unsaturated molecules is accurately computed using a combination of ab initio quantum mechanical calculations and free energy perturbation methods. Initial attempts to calculate the absolute hydration free energy difference (ΔGhyd) for formaldehyde and trichloroacetaldehyde gave values that differed substantially from experimental results even after inclusion of electron correlation energy contributions using third-order (MP3) and fourth-order (MP4) Møller-Plesset perturbation theory and QCISD(T) correlation methods at the 6-31G** basis set level. Inaccuracies in ΔGhyd were attributed to errors in the calculation of both ΔGgas and ΔΔGsol. Gas phase quantum mechanical free energies (ΔGgas) varied significantly (2–3 kcal/mol) depending on the level of theory. Errors in ΔΔGsol were attributed to slow convergence of the calculations using the thermodynamic cycle perturbation (TCP) method with explicit solvent. These errors were minimized or canceled, however, when relative hydration free energy differences (ΔΔGhyd) were calculated using a combination of ab initio quantum mechanical calculations and free energy perturbation methods. Calculated values for a variety of aldehydes and ketones were consistent with experimental data. © 1995 John Wiley & Sons, Inc. 相似文献
108.
A. Fahli J. P. Coffin G. Guillaume B. Heusch F. Jundt F. Rami P. Wagner P. Fintz A. J. Cole S. Kox Y. Schutz N. Cindro 《Zeitschrift für Physik A Hadrons and Nuclei》1987,326(2):169-177
The light charged particles emitted in the40Ar+68Zn reaction performed at 14.6, 19.6 and 35 MeV/nucleon have been studied inclusively. The energy spectra have been analysed in terms of preequilibrium emission, moving source and coalescence models. A complete coherence between the present data and those obtained separately from heavy fragment studies is achieved. These data are consistent with the onset of projectile fragmentation between 20 and 35 MeV/nucleon correlated with the formation of a highly excited region of the nuclear system inducing light particle emission. The other sources of light particles can be interpreted as statistical and sequential decay of the quasi projectile. 相似文献
109.
Valentina A. Ol’shevskaya Rami Ayuob Pavel V. Petrovskii Galina L. Levit Valery N. Charushin Valery N. Kalinin 《Journal of organometallic chemistry》2005,690(11):2761-2765
General method for preparation of high yields of novel N-protected carborane amino acid derivatives, 3-acylamino-1-carboxymethyl-2-R-o-carboranes (R = H, Me, Ph), is reported. The synthesis starts from readily available 3-amino-o-carboranes and includes the protection of amino group, introduction of carboxymethyl function to the carbon atom of polyhedron via the metallation of carborane CH bond with sodium amide in liquid ammonia, and treatment of corresponding sodium carboranes with sodium bromoacetate. Deprotection of N-acylated carborane amino acids is studied in acidic media. Depending on the procedure employed, closo- or nido-carborane amino acids were obtained. 相似文献
110.
Copolymers of ethyl acrylate (M1) and n-butyl methacrylate (M2) were prepared by benzoyl peroxide initiation in solution at 60° and copolymer compositions estimated by [13C]-NMR spectroscopy. The kinetic behaviour is approximately ideal with r1 = 1/r2 = 0.47. Relaxation times T1 were determined for six of the carbons in M2 units and one in the M1 units; they range from 0.07 to 1.65 sec. 相似文献