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排序方式: 共有158条查询结果,搜索用时 15 毫秒
51.
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
52.
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
53.
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.
Surface phases and photocatalytic activity correlation of Bi2O3/Bi2O4-x nanocomposite 总被引:1,自引:0,他引:1
Hameed A Montini T Gombac V Fornasiero P 《Journal of the American Chemical Society》2008,130(30):9658-9659
UV-visible irradiation induces surface alteration of Bi2O3 leading to Bi2O3/Bi2O4-x nanocomposites with excellent photocatalytic activity. 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.
Influence of Metal Oxides on Platinum Activity towards Methanol Oxidation in H2SO4 solution 下载免费PDF全文
Dr. R. M. Abdel Hameed Dr. R. S. Amin Prof. K. M. El‐Khatib Dr. Amani E. Fetohi 《Chemphyschem》2016,17(7):1054-1061
Pt–CeO2/C, Pt–TiO2/C, and Pt–ZrO2/C electrocatalysts were prepared by using a modified microwave‐assisted polyol process. Physical characterization was performed by using XRD, TEM, and EDX analyses. The incorporation of different metal oxides increased the dispersion degree of Pt nanoparticles and reduced their diameter to 2.50 and 2.33 nm when TiO2 and ZrO2 were introduced to Pt/C, respectively. The electrocatalytic activity of various electrocatalysts was examined towards methanol oxidation in H2SO4 solution by using cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. Among the studied composites, Pt–ZrO2/C was selected to be a candidate electrocatalyst for better electrochemical performance in direct methanol fuel cells. 相似文献
60.
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