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Molecular Diversity - Spirocyclic compounds fascinate the synthetic chemists due to their privileged ring system and efficacy in drug discovery. Many natural compounds comprise spirocyclic moiety... 相似文献
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Ion acoustic solitary waves in a quantum plasma, which is slowly rotating around an axis at an angle θ with the direction of magnetic field, are investigated. Quantum hydrodynamic model is under consideration with the effects of rotations which are included via Coriolis force. Fermions are degenerate and have different spin density states, that is, up and down characterized via parameter α. Linear analysis is performed by applying Fourier transformation to derive dispersion relation. For nonlinear analysis, we apply reductive perturbation method to derive Korteweg de Vries equation (KdV). The effects of variations of Coriolis force, spin polarization, and quantum parameter on characteristics of solitary structure are discussed. These results are applicable to astrophysical and laboratory plasmas. 相似文献
106.
A novel one-pot pseudo five-component reaction of isocyanides with 2,5-dihydroxycyclohexa-2,5-diene-1,4-dione and various aliphatic and aromatic aldehydes in ethanol at room temperature has been studied. 2,6-Bis(alkylamino)-benzofuro[5,6-b]furan-4,8-dione derivatives were isolated as the products in good yields after 24 h. 相似文献
107.
Ahmad Shaabani Afshin Sarvary Ali Hossein Rezayan Sajjad Keshipour 《Tetrahedron》2009,65(17):3492-1644
The three-component reaction of the zwitterions generated from dialkyl acetylenedicarboxylate and isocyanides with 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one is described. The reaction afforded the corresponding special type of fully substituted pyrano[2,3-c]pyrazole derivatives in good yields without using any catalyst and activation. 相似文献
108.
M. Sajjad Athar S. Chauhan S. K. Singh 《The European Physical Journal A - Hadrons and Nuclei》2010,43(2):209-227
Super-Kamiokande has reported the results for the lepton events in the atmospheric neutrino experiment. These results have been presented for a 22.5kT water fiducial mass on an exposure of 1489 days, and the events are divided into sub-GeV, multi-GeV and PC events. We present a study of nuclear medium effects in the sub-GeV energy region of atmospheric neutrino events for the quasielastic scattering, incoherent and coherent pion production processes, as they give the most dominant contribution to the lepton events in this energy region. We have used the atmospheric neutrino flux given by Honda et al. These calculations have been done in the local density approximation. We take into account the effects of Pauli blocking, Fermi motion, Coulomb effect, renormalization of weak transition strengths in the nuclear medium in the case of the quasielastic reactions. The inelastic reactions leading to production of leptons along with pions is calculated in a $ \Delta$ -dominance model by taking into account the renormalization of $ \Delta$ properties in the nuclear medium and the final-state interaction effects of the outgoing pions with the residual nucleus. We present the results for the lepton events obtained in our model with and without nuclear medium effects, and compare them with the Monte Carlo predictions used in the simulation and the experimentally observed events reported by the Super-Kamiokande Collaboration. 相似文献
109.
Sumrra Sajjad H. Sahrish Ifza Raza Muhammad A. Ahmad Zahoor Zafar Muhammad N. Chohan Zahid H. Khalid Muhammad Ahmed Saeed 《Monatshefte für Chemie / Chemical Monthly》2020,151(4):549-557
Monatshefte für Chemie - Chemical Monthly - In the present research, novel unsymmetrically substituted triazole-derived Schiff base ligand... 相似文献
110.
Elias Paiva Ferreira-Neto Sajjad Ullah Orlando Armando Elguera Ysnaga Ubirajara Pereira Rodrigues-Filho 《Journal of Sol-Gel Science and Technology》2014,72(2):290-300
Owing to the wide use of photochromic materials in UV sensors and dosimeters, considerable efforts have been made to increase the UV-response and sensitivity of the existing classes of photochromic materials. In this study, we report a simple sol–gel route for the preparation of highly photochromic transparent films based on ormosil–phosphotungstate hybrid materials. The effect of addition of Zn2+ ions on the photochromic response of these hybrid films and the possible mechanism involved is discussed. Compared to the undoped samples, the photochromic response of the Zn2+-doped hybrid films increases by 59–237 % depending on the concentration of Zn2+ ions added to the sol formulation. No structural or electronic change in the phosphotungstate dye was observed by vibrational spectroscopy or UV spectroscopy, though micro X-ray fluorescence (μ-XRF) analysis showed that the addition of Zn2+ in the sol–gel preparations leads to an increase in the amount of phosphotungstate (HPW) incorporated in the dip-coated films. Furthermore, TEM and nano-energy-dispersive X-ray showed formation of nano-agglomerates consisting of Zn and HPW in the Zn2+-doped samples. Zn K-edge X-ray absorption near edge structure analysis also confirmed the formation of the salt Hx[Zn(OH2)6] 2?xPW12O40. It is suggested that these Zn-phosphotungstate nano-agglomerates get trapped into the ormosil network during films preparation leading to increased concentration of the phosphotungstate anions in the films, in accordance with results from μ-XRF analysis. Raman spectroscopy confirmed that the Keggin structure of HPW is preserved in the hybrid films. FTIR spectra of the matrix part of the samples are identical before and after UV-irradiation, which suggests that the photochromic process does not involve oxidation of the organic functionalities. These highly photochromic hybrid films are promising candidates for the design of practical UV-sensing devices and dosimeters. 相似文献