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51.
MUHAMMAD Naeem Ahmed IFZAN Arshad WANG Bo SHAHID Hameed BILAL Ahmad Khan KHAWAJA Ansar Yasin MUHAMMAD Moazzam Naseer 《结构化学》2014,(12)
One-pot three component reaction was used to synthesize 1,4,5-trisubstituted 1,2,3-triazole(A) from the corresponding acid chloride, benzyl azide and 1-copper(I) phenylethyne. The molecular structure was determined by single-crystal X-ray analysis. The compound crystallizes in the orthorhombic space group Pbca, a = 14.9815(14), b = 9.6496(10), c = 25.528(2) A, Z = 8. Furthermore, crystal packing demonstrated a molecular wall-like structure based on supramolecular chains of A, stabilized by CH···O, CH···Br, N···C and CH···π interactions. Molecular geometry in the ground state has been determined by density functional theory(DFT) by B3LYP/6-311G* basis set and compared with the experimental data. The computed vibrational frequencies are compared with the experimental FT-IR data and frontier molecular orbital analyses were performed at the same level of theory. Theoretical parameters are in good agreement with the corresponding X-ray diffraction values. 相似文献
52.
Numerical and analytical solutions of an Oldroyd 8‐constant MHD fluid with nonlinear slip conditions
The flow of an Oldroyd 8‐constant non‐Newtonian MHD fluid is investigated analytically and numerically. The governing equations for the flow field are derived for a steady one‐dimensional flow. The effect of constant applied magnetic field is included and its influence on the flow field is studied. The nonlinear governing equation along with nonlinear boundary conditions is solved analytically and the solution is obtained in an elegant way. Numerical solutions are also obtained using higher order Chebyshev spectral methods. The influence of various non‐Newtonian parameters and applied magnetic field is investigated. Results showing the effect of various physical parameters of the flow are presented and investigated. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
53.
Hameed Ahmed Khan 《辐射效应与固体损伤》2013,168(2):71-73
The studies regarding the annealing properties of a pre-irradiation annealed Makrofol N track detector showed that under “moderate annealing conditions”, the maximum etched track length lmax, can be increased. The increase becomes maximum at pre- and post-irradiation annealing temperatures of 80°C and 60°C respectively. 相似文献
54.
P. Shahul Hameed G. Sankaran Pillai G. Satheeshkumar R. Mathiyarasu 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(3):1081-1088
Tiruchirappalli district is naturally endowed with rich building material resources which are also used in neighboring districts. Hence, measurements of activity concentrations and absorbed dose rate of primordial radionuclides (238U, 232Th and 40K) in the rock samples collected from 14 sedimentary rocks and 9 igneous rocks were carried out employing gamma ray spectrometry. In sedimentary rocks the geometric mean activity concentrations of 238U, 232Th and 40K were found to be 7.4, 29.5 and 233.6 Bq kg?1, respectively. On the other hand in igneous rocks geometric mean activity concentrations of 238U, 232Th and 40K were distinctly higher and found to be 13.1, 105.7 and 888.8 Bq kg?1, respectively. The mean radium equivalent activity (Raeq) recorded in both sedimentary (20.8 Bq kg?1) and igneous rocks (245.4 Bq kg?1) were well within the limit prescribed for dwellings (370 Bq kg?1) except Vilathupatti (689.3 Bq kg?1) and Narthamalai (371.6 Bq kg?1). The mean absorbed dose rate from igneous rock (115 nGy h?1) exceeded the prescribed limit of 55 nGy h?1. The mean indoor annual effective dose from the sedimentary rock (0.056 mSv y?1) and igneous rock (0.580 mSv y?1) did not exceed the prescribed limit (1 mSv y?1) except the igneous rock from Vilathupatti (1.51 mSv y?1). The study concludes that sedimentary and igneous rocks analyzed were radiologically safe when used as building materials except igneous rock from Vilathupatti and Narthamalai. 相似文献
55.
Over the past couple of years, the resurgence of placing an effective and sustainable amendment to combat against the auxiliary industrial entities, remains a highly contested agenda from a global point. With the renaissance of activated carbon, there has been a steadily growing interest in the research field. Recently, the adoption of zeolite composite, a prestigious advanced catalyst which formulates the enhancement of adsorption rate and hydrogen storage capability, has fore fronted to be a new growing branch in the scientific community. Confirming the assertion, this paper presents a state of art review of activated carbon/zeolite composite technology, its fundamental background studies, and environmental implications. Moreover, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of activated carbon/zeolite composite represents a potentially viable and powerful tool, leading to the plausible improvement of environmental preservation. 相似文献
56.
Seraj Faiza Kanwal Khan Khalid Mohammed Khan Ajmal Ali Muhammad Khalil Ruqaiya Ul-Haq Zaheer Hameed Shehryar Taha Muhammad Salar Uzma Perveen Shahnaz 《Molecular diversity》2021,25(1):143-157
Molecular Diversity - Novel ibuprofen derivatives 1–19 including ibuprofen hydrazide 1, and substituted thiourea derivatives 2–19 were synthesized and characterized by EI-MS, FAB-MS,... 相似文献
57.
A second generation formal synthesis of the alkaloid (-)-cephalotaxine has been achieved using an alkylidene carbene 1,5-CH insertion reaction to establish a key quaternary stereocenter. The carbene precursor was readily derived from L-proline, and the 1,5-CH insertion reaction was performed under Ohira's conditions using lithiotrimethylsilyldiazomethane (LTDM), which gave the desired spirocyclic product in 74% yield. The hydroxymethyl group was then oxidized and then decarbonylated (93%), and this material was easily transformed into the desired Friedel-Crafts cyclization precursor. Exposure of this material to SnCl4 then gave the desired pentacyclic product, which was identical to that previously prepared by Mori and thus represents a formal total synthesis of (-)-cephalotaxine. 相似文献
58.
Direct Electrochemical Sensing of Phenazine‐1‐carboxylic Acid Secreted by Pseudomonas chlororaphis subsp. aureofaciens BCRC 11057T Using Disposable Screen‐printed Carbon Electrode 下载免费PDF全文
Asif Hameed Hong‐Wei Pi Shih‐Yao Lin Wei‐An Lai Li‐Sen Young You‐Cheng Liu Fo‐Ting Shen Chiu‐Chung Young 《Electroanalysis》2016,28(4):846-853
A novel electrochemical approach for direct recognition of antibiotic phenazine‐1‐carboxylic acid (PCA) was developed. PCA was electropolymerized on preanodized screen‐printed carbon electrode (SPCE*‐PCA) through repetitive cyclic voltammetry and characterized by XPS and FESEM. Electron transfer involved intermediate phenomenon of diffusion‐controlled redox process and surface bound redox reaction. At pH 8 (optimum), SPCE*‐PCA had a detection limit of 0.51±0.04 μM, a quantification limit of 1.7±0.13 μM, linearity of up to 50 µM, a repeatability of 15.5 % and a reproducibility of 1.7 %. PCA secreted by Pseudomonas chlororaphis subsp. aureofaciens BCRC 11057T was investigated successfully using present single run approach. 相似文献
59.
JPC – Journal of Planar Chromatography – Modern TLC - A rapid, sensitive, and eco-friendly micellar high-performance thin-layer chromatography (HPTLC) technique for the simultaneous... 相似文献
60.
Families of parameter dependent univariate and bivariate subdivision schemes are presented in this paper. These families are new variants of the Lane-Riesenfeld algorithm. So the subdivision algorithms consist of both refining and smoothing steps. In refining step, we use the quartic B-spline based subdivision schemes. In smoothing step, we average the adjacent points. The bivariate schemes are the non-tensor product version of our univariate schemes. Moreover, for odd and even number of smoothing steps, we get the primal and dual schemes respectively. Higher regularity of the schemes can be achieved by increasing the number of smoothing steps. These schemes can be nicely generalized to contain local shape parameters that allow the user to adjust locally the shape of the limit curve/surface. 相似文献