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排序方式: 共有202条查询结果,搜索用时 281 毫秒
91.
Suphawat Asawasamrit Muhammad Aamir Ali Sotiris K. Ntouyas Jessada Tariboon 《Entropy (Basel, Switzerland)》2021,23(8)
Quantum information theory, an interdisciplinary field that includes computer science, information theory, philosophy, cryptography, and entropy, has various applications for quantum calculus. Inequalities and entropy functions have a strong association with convex functions. In this study, we prove quantum midpoint type inequalities, quantum trapezoidal type inequalities, and the quantum Simpson’s type inequality for differentiable convex functions using a new parameterized q-integral equality. The newly formed inequalities are also proven to be generalizations of previously existing inequities. Finally, using the newly established inequalities, we present some applications for quadrature formulas. 相似文献
92.
Guangle Zhang Kuanysh Khabibullin Aamir Farooq 《Proceedings of the Combustion Institute》2019,37(2):1445-1452
Extended wavelength tuning of an IH-QCL (integrated heater quantum cascade laser) is exploited for simultaneous detection of methane and acetylene using direct absorption spectroscopy. The integrated heater, placed within few microns of the laser active region, enables wider wavelength tuning than would be possible with a conventional DFB (distributed feedback) QCL. In this work, the laser current and heater resistor current are modulated simultaneously at 25?kHz to tune the laser over 1279.6–1280.1 cm?1, covering absorption transitions of methane and acetylene. The laser is characterized extensively to understand the dependence of wavelength tuning on modulation frequency, modulation amplitude and phase difference between laser/heater modulation. Thereafter, the designed sensor is validated in both room-temperature static cell experiments and non-reactive high-temperature-measurements in methane-acetylene-argon gas mixtures in the shock tube. Finally, the sensor is applied for simultaneous detection of methane and acetylene during the high-temperature pyrolysis of iso-octane behind reflected shock waves. 相似文献
93.
Noreen Sajjad Raha Orfali Shagufta Perveen Sabiha Rehman Aeysha Sultan Taslim Akhtar Arif Nazir Gulzar Muhammad Tahir Mehmood Safina Ghaffar Areej Al-Taweel Muhammad I. Jilani Munawar Iqbal 《Molecules (Basel, Switzerland)》2022,27(10)
Biodiesel is considered a sustainable alternative to petro-diesel owing to several favorable characteristics. However, higher production costs, primarily due to the use of costly edible oils as raw materials, are a chief impediment to its pecuniary feasibility. Exploring non-edible oils as raw material for biodiesel is an attractive strategy that would address the economic constraints associated with biodiesel production. This research aims to optimize the reaction conditions for the production of biodiesel through an alkali-catalyzed transesterification of Tamarindus indica seed oil. The Taguchi method was applied to optimize performance parameters such as alcohol-to-oil molar ratio, catalyst amount, and reaction time. The fatty acid content of both oil and biodiesel was determined using gas chromatography. The optimized conditions of alcohol-to-oil molar ratio (6:1), catalyst (1.5% w/w), and reaction time 1 h afforded biodiesel with 93.5% yield. The most considerable contribution came from the molar ratio of alcohol to oil (75.9%) followed by the amount of catalyst (20.7%). In another case, alcohol to oil molar ratio (9:1), catalyst (1.5% w/w) and reaction time 1.5 h afforded biodiesel 82.5% yield. The fuel properties of Tamarindus indica methyl esters produced under ideal conditions were within ASTM D6751 biodiesel specified limits. Findings of the study indicate that Tamarindus indica may be chosen as a prospective and viable option for large-scale production of biodiesel, making it a substitute for petro-diesel. 相似文献
94.
95.
Orhan Atakol Hasan Nazir Zehra Durmus Ingrid Svoboda Hartmut Fuess 《Analytical sciences》2002,18(4):493-494
96.
James H. Looker Nazir A. Khatri Ronald B. Patterson Charles A. Kingsbury 《Journal of heterocyclic chemistry》1978,15(8):1383-1385
Natural abundance 13C nmr spectra are reported for 1,2,3-thiadiazole and nine derivatives. The spectra are discussed in terms of α- and β-effects of substituent groups and compared with corresponding spectra of alkene and benzene derivatives. 13C nmr spectra of four 1,3,4-thiadiazoles are presented. Spectral data indicate that in dimethylsulfoxide solution 2-mercapto-5-methyl-1,3,4-thiadiazole exists predominantly as the thione tautomer. 相似文献
97.
All the geometric isomers of the benzoate derivatives, XC6H4CO2− (X=F, Cl, Br, OH, OCH3, NO2, CO2CH3, NH2, N(CH3)2) can be intercalated into the layered double hydroxide [LiAl2(OH)6]Cl·H2O in 50% (v/v) water/ethanol solution at 80 °C to give fully anion-exchanged first stage intercalation compounds [LiAl2(OH)6]G·yH2O (G=a substituted benzoate). The observed interlayer separations of the intercalates vary from 14.3 Å for [LiAl2(OH)6](4-nitrobenzoate)·2H2O to 20.6 Å for [LiAl2(OH)6](3-dimethylaminobenzoate)·3H2O. Competitive intercalation studies using mixtures of isomeric benzoates showed that the 4-isomers and 2-isomers are the most and the least preferred anions, respectively. Comparing the calculated dipole moments of the anions with the observed isomeric intercalation preferences suggests that dipole moment may be a good general index for the preference; however, it should be remembered that the bulkiness and electronegativity of the other substituent could be very important factors that affect the preferential intercalation. 相似文献
98.
99.
Muhammad Aamir Sajid Sohail Anjum Shahzad Fatima Hussain W. G. Skene Muhammad Yar 《合成通讯》2018,48(15):1893-1908
Chitin and chitosan are well-thought-out multipurpose biopolymers. Chitosan which is deacetylated chitin is useful than chitin and is biomaterial of great interest. Regardless of its biodegradability, chemical modifications suggest due to the amino side reactivity, helps to impart it other great qualities. Herein, we discuss the preparative methods of synthetically modified derivatives, some are commercially available. This review shields the literature from last few decades. 相似文献
100.
Comparison of UV Protection Properties of Cotton Fabrics Treated with Aqueous and Methanolic Extracts of Achyranthes aspera and Alhagi maurorum Plants
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Ahsan Nazir Muhammad Asad Saleem Faiza Nazir Tanveer Hussain Muhammad Qasim Faizan Muhammad Usman 《Photochemistry and photobiology》2016,92(2):343-347
UV radiations are high‐energy radiations present in sunlight that can damage human skin. Protection against these radiations becomes vital especially in those areas of the globe where UV index is quite high that makes the inhabitants more prone to dangerous effects of UV radiations. Clothing materials are good blockers of UV radiations, particularly when the fabric cover factor is high and/or the fabrics contain suitable UV‐blocking finishes. In this study, effect of application of aqueous and methanolic extracts of two different plants, i.e., Achyranthes aspera and Alhagi maurorum on UV protection properties of cotton fabric was investigated. The results showed that the fabric samples treated with extracts of both the plants have excellent UV protection properties as indicated by their ultraviolet protection factor. It was concluded that both the aqueous and methanolic plant extracts are very effective in blocking UVA and UVB radiations, when applied on cotton fabrics. The UV protection performance of Achyranthes aspera extracts was much better as compared to that of Alhagi maurorum, and methanolic extracts of both the plants outperformed the aqueous extracts in terms of UV protection. 相似文献