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排序方式: 共有489条查询结果,搜索用时 750 毫秒
1.
Mathematical Programming - We consider the generalized trust region subproblem (GTRS) of minimizing a nonconvex quadratic objective over a nonconvex quadratic constraint. A lifting of this... 相似文献
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Queiroz Ana Luiza P. Kerins Brian M. Yadav Jayprakash Farag Fatma Faisal Waleed Crowley Mary Ellen Lawrence Simon E. Moynihan Humphrey A. Healy Anne-Marie Vucen Sonja Crean Abina M. 《Cellulose (London, England)》2021,28(14):8971-8985
Cellulose - Microcrystalline cellulose (MCC) is a semi-crystalline material with inherent variable crystallinity due to raw material source and variable manufacturing conditions. MCC crystallinity... 相似文献
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Utility of 4‐Benzylidene‐2‐phenyl‐5(4H)‐oxazolone in Synthesis of Triazine,Oxadiazole and Imidazole Derivatives of Anticipated Biological Activity 下载免费PDF全文
Ahmed S. A. Youssef Fatma A. El‐Mariah Fatma T. Abd‐Elmottaleb Heba E. Hashem 《Journal of heterocyclic chemistry》2015,52(5):1467-1473
Treatment of oxazolone 1 with hydrazine hydrate at room temperature gave the (Z)‐configurated isomer hydrazide (Z)‐ 3 (high yield). However, refluxing 1 with hydrazine hydrate yielded the (E)‐configurated isomer hydrazide (E)‐ 2 (low yield).The hydrazide derivative (Z)‐ 3 has been utilized as synthon for the synthesis of 1,2,4‐triazinone, imidazolone, and oxadiazole derivatives through appropriate routes. The thiosemicarbazide and semicarbazide derivatives are synthesized by different routes. The structures of the new compounds were established on the basis of IR, 1H‐NMR, mass spectral data, and elemental analysis. 相似文献
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Synthesis of New Pyrazoles via Cycloaddition Reactions of Nitrilimines with 2‐Cyclopentenone Derivatives 下载免费PDF全文
Fatma A. El‐Samahy 《Journal of heterocyclic chemistry》2015,52(2):597-602
Compounds 1,3,6,6a‐tetraphenyl‐1,6a‐dihydrocyclopenta[c]pyrazol‐4(3aH)‐ones ( 3 ), 1,3,3a,4‐tetraphenyl‐1,3a‐dihydrocyclopenta[c]pyrazol‐6‐ols ( 4 ) and 6‐hydroxy‐1,3,6,6a‐tetraphenyl‐1,5,6,6a‐tetrahydrocyclopenta[c]pyrazole‐4(aH)‐one ( 5 ) were synthesized by reaction of 3,4‐diphenyl‐4‐hydroxy‐2‐cyclopentenone ( 2a ) with nitrilimines, generated in situ by the action of triethylamine on the corresponding hydrazonyl chlorides 1 . 相似文献
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Trietazine was selectively separated from aqueous solution containing the competitor molecule cyanazine, which is similar in size and shape to the template molecule. Structural features of the molecularly imprinted column were figured out by SEM. The influence of the mobile‐phase composition, applied electrical field, and pH of the mobile phase on the recognition of trietazine by the imprinted monolithic polymer has been evaluated, and the imprint effect in the trietazine‐imprinted monolithic polymer was demonstrated by an imprinting factor. The optimized monolithic column resulted in separation of trietazine from a structurally related competitor molecule, cyanazine. In addition, fast separation was obtained within 6 min by applying higher electrical field, with the electrophoretic mobility of 2.97 × 10?8 m2V?1s?1 at pH 11.0. 相似文献
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An inverse coefficient problem for a quasilinear parabolic equation with periodic boundary and integral overdetermination condition 下载免费PDF全文
In this paper, the inverse problem of finding the time‐dependent coefficient of heat capacity together with the solution periodic boundary and integral overdetermination conditions is considered. Under some natural regularity and consistency conditions on the input data, the existence, uniqueness, and continuous dependence upon the data of the solution are shown. Some considerations on the numerical solution for this inverse problem are presented with an example. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Safaa El‐din H. Etaiw Hassan Marie Elsayed M. Shalaby Rabie S. Farag Fatma A. Elsharqawy 《应用有机金属化学》2019,33(9)
Orange prismatic crystals of the supramolecular coordination polymer (SCP) ∞3[Cu(CN)2(Me3Sn)(Pyz)], SCP 1 , were synthesized using a self‐assembly method under ambient conditions. Nanosized 1 was obtained using the same molar ratio in water by ultrasonic irradiation. SCP 1 was characterized using single‐crystal X‐ray diffraction, elemental analysis, thermal analysis and Fourier transform infrared spectroscopy. SCP 1 and its nanosized 1 particles were also examined using powder X‐ay diffraction and scanning electron microscopy. The luminescence emission of SCP 1 was studied as well as its use as a sensor for the detection of common organic solvents and metal ions. Also, the catalytic activities of nanosized 1 towards various organic dyes were investigated under ambient conditions, UV irradiation and ultrasonic irradiation. Nanosized 1 as a heterogeneous nanoparticle catalyst exhibits high catalytic activity for the degradation of eosin‐Y and acid blue dyes. The mechanism of degradation investigated using various scavenger techniques is proposed and discussed. The catalytic oxidation process is mainly caused by ?OH radicals. 相似文献
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Sara Taha Gelan Rafat Fatma Aboshosha Fotouh R. Mansour 《Journal of Analytical Chemistry》2017,72(2):239-242
A simple portable spectrophotometer was constructed and used to perform analytical experiments. The developed model uses available tools and materials such as light emitting diode lamps, compact discs, plastic and cardboard boxes and a cell phone camera to build a design that illustrates the major components of spectrophotometers. The spectra of serial concentrations of KMnO4 (50?600 μM) were recorded and the values of absorbance were extracted at λmax to build the calibration curve. A linear relationship between the concentration and absorbance was obtained with the coefficient of determination 0.994. The model was also utilized to study the spectra of KMnO4, phenolphthalein and bromothymol blue in comparison with a Shimadzu UV-1800 spectrophotometer as a reference instrument. In spite of the differences in the observed spectra, the recorded λmax were almost identical to those measured by the developed model. The model was successfully used to determine the concentration of sodium alendronate through ligand-exchange complexation with ferric salicylate. 相似文献
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