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排序方式: 共有165条查询结果,搜索用时 15 毫秒
21.
Shahbaz Ali Muneeba Kousar Qin Xin Dragan Pamu
ar Muhammad Shazib Hameed Rabia Fayyaz 《Entropy (Basel, Switzerland)》2021,23(11)
In this research article, we motivate and introduce the concept of possibility belief interval-valued N-soft sets. It has a great significance for enhancing the performance of decision-making procedures in many theories of uncertainty. The N-soft set theory is arising as an effective mathematical tool for dealing with precision and uncertainties more than the soft set theory. In this regard, we extend the concept of belief interval-valued soft set to possibility belief interval-valued N-soft set (by accumulating possibility and belief interval with N-soft set), and we also explain its practical calculations. To this objective, we defined related theoretical notions, for example, belief interval-valued N-soft set, possibility belief interval-valued N-soft set, their algebraic operations, and examined some of their fundamental properties. Furthermore, we developed two algorithms by using max-AND and min-OR operations of possibility belief interval-valued N-soft set for decision-making problems and also justify its applicability with numerical examples. 相似文献
22.
Chiral recognition of aryl alkyl selenides and alkyl iodides can be achieved by 1H NMR spectroscopy in the presence of dirhodium tetra-(R)-or tetra-(S)-α-methoxy-α-(trifluoromethyl)-phenylacetate [Rh2(MTPA)4, 1 ]. Generally, these classes of compounds are weak donors and fail when using the classical chiral lanthanoid shift reagent. Alkyl bromides do not show similar effects. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:471–474, 1998 相似文献
23.
Ali Jasim Hammood Ahmed Fadhel H. Kased Sameem R. Raseen Ivan Hameed R. Tomi Al-Ameen Bariz Omar Ali 《Molecular Crystals and Liquid Crystals》2017,648(1):114-129
A series of hydrophobic symmetrical azines: 1,2-bis[4-(n-alkoxy)benzylidene]hydrazine (where, n-alkoxy: O(CH2)nH, n = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 16, or 18) have been prepared following an efficient and practical method. These compounds have been synthesized via the condensation reaction of hydrazine hydrate and appropriately 4-(n-alkoxy) benzaldehydes in acidic medium under ambient conditions. The prepared organic compounds have been characterized and their structures were elucidated depending upon micro-elemental analysis and spectral data (IR, UV-Vis, 1HNMR, 13C{1H}NMR, 2D 1H-1H-cozy, 2D 1H-13C-HSQC, and mass spectra). Liquid crystalline behavior of the prepared compounds was studied using polarized light optical microscopy and differential scanning calorimetry techniques. This study revealed that all the compounds displayed enantiotropic liquid crystal properties, exhibiting smectic and nematic mesophases. 相似文献
24.
Afaf M.Abdel Hameed 《中国化学快报》2012,23(4):411-414
Azidation of aminothiophene derivative 1 afforded the corresponding azido derivative 2.The latter reacted with triphenylphosphine to afford iminophosphorane derivatives 3.Reacting 3 with phenylisocyanate gave the highly reactive carbodiimide intermediate 4,which was reacted with different nitrones to afford new l,2,4-oxadiazolidin-5-ylidene-aminothiophenes 5a-c. Treatment of 4 with absolute EtOH at room temperature gave methyleneamino-5-(methylthio)thiophene 7,(methylthio)-3-(3- phenylureidothiophene)-2-carboxylate 8 or thienopyrimidine 9 and 10 at refluxing temperature.Finally reaction of carbodiimide intermediate 4 with different secondary amines gave the new thienopyrimidines 11a-c. 相似文献
25.
AH Karim AA Jalil S Triwahyono SM Sidik NH Kamarudin R Jusoh NW Jusoh BH Hameed 《Journal of colloid and interface science》2012,386(1):307-314
In this work, mesostructured silica nanoparticles (MSN(AP)) with high adsorptivity were prepared by a modification with 3-aminopropyl triethoxysilane (APTES) as a pore expander. The performance of the MSN(AP) was tested by the adsorption of MB in a batch system under varying pH (2-11), adsorbent dosage (0.1-0.5gL(-1)), and initial MB concentration (5-60mgL(-1)). The best conditions were achieved at pH 7 when using 0.1gL(-1) MSN(AP) and 60mgL(-1)MB to give a maximum monolayer adsorption capacity of 500.1mgg(-1) at 303K. The equilibrium data were evaluated using the Langmuir, Freundlich, Temkin, and Harkins-Jura isotherms and fit well to the Freundlich isotherm model. The adsorption kinetics was best described by the pseudo-second order model. The results indicate the potential for a new use of mesostructured materials as an effective adsorbent for MB. 相似文献
26.
Aiswarya Poulose Jyotishkumar Parameswaranpillai Jinu Jacob George Jineesh Ayippadath Gopi Senthilkumar Krishnasamy Midhun Dominic C. D. Nishar Hameed Nisa V. Salim Sabarish Radoor Natalia Sienkiewicz 《Molecules (Basel, Switzerland)》2022,27(22)
Recently, considerable interest has been focused on developing greener and biodegradable materials due to growing environmental concerns. Owing to their low cost, biodegradability, and good mechanical properties, plant fibers have substituted synthetic fibers in the preparation of composites. However, the poor interfacial adhesion due to the hydrophilic nature and high-water absorption limits the use of plant fibers as a reinforcing agent in polymer matrices. The hydrophilic nature of the plant fibers can be overcome by chemical treatments. Cellulose the most abundant natural polymer obtained from sources such as plants, wood, and bacteria has gained wider attention these days. Different methods, such as mechanical, chemical, and chemical treatments in combination with mechanical treatments, have been adopted by researchers for the extraction of cellulose from plants, bacteria, algae, etc. Cellulose nanocrystals (CNC), cellulose nanofibrils (CNF), and microcrystalline cellulose (MCC) have been extracted and used for different applications such as food packaging, water purification, drug delivery, and in composites. In this review, updated information on the methods of isolation of nanocellulose, classification, characterization, and application of nanocellulose has been highlighted. The characteristics and the current status of cellulose-based fiber-reinforced polymer composites in the industry have also been discussed in detail. 相似文献
27.
Ali Farooq H. Hamzah Hameed K. Mozaffari Masoud Mehryan S. A. M. Ghalambaz Mohammad 《Journal of Thermal Analysis and Calorimetry》2020,141(5):1801-1816
Journal of Thermal Analysis and Calorimetry - In this study, the heat transfer, fluid flow and heat capacity ratio are analyzed in an annulus enclosure filled with porous and saturated by a... 相似文献
28.
Wajiha Ahmad Sundus Riaz Nasir Mehmood Ahmad Maryam Hameed Ayesha Naeem 《Natural product research》2018,32(8):968-971
Plant phytochemicals, such as flavonoids are in use for the development of optical biosensor. Benzo[a]pyrene (B[a]P), is a pervasive environmental and dietary carcinogen. A fluorescent assay is developed using plant isolated flavonoid for the detection of B[a]P. High content saponins are excluded from the flavonoid-containing methanolic extract of Corchorus depressus by implying reduction of silver ions by saponins resulting in formation of silver nanoparticles. Isolated plant flavonoids are used to develop a spectrofluorometric assay for the detection of B[a]P. Decrease in the flavonoid fluorescence intensity by B[a]P is found to be based on both static and dynamic quenching. Specificity of the assay for B[a]P was tested for other carcinogens belonging to different classes of compounds. Flavonoids-mediated sensing can be implied for the development of new generation of nanoparticle-based biosensors that can be more sensitive and less susceptible to external factors, such as temperature and humidity. 相似文献
29.
Zafar Ali Shah Saba Farooq Syed Abid Ali Abdul Hameed M. Iqbal Choudhary 《合成通讯》2018,48(10):1172-1182
The peptide temporin-LK1 (1) was obtained from the skin secretion of frog Limnonectes kuhlii (Ranidae). It is a unique antimicrobial peptide with 17 residues, including four L-phenylalanines and single glycine. Mass spectrometry and Edmand degradation were used for the determination of sequence of amino acids in temporin-LK 1 (1), and confirmed by cDNA cloning. We report here the synthesis and structural studies of temporin-LK1 (1) and its analogs 2–4. Peptides 2–4 were prepared by substitution of achiral glycine residue of temporin-LK1 (1) with D-alanine, L-phenylglycine, and L-naphthylalanine, respectively. Peptides 1–4 were evaluated against multidrug-resistant (MDR) strains of Staphylococcus aureus and Pseudomonas aeruginosa. Analog 2 was found active against all MDR strains of S. aureus and P. aeruginosa at a much lower dose than the clinically used antibiotics. 相似文献
30.
The differential pulse polarographic behaviour of benzoylhydrazine, m-methoxy benzoyl-hydrazine, and o-methoxy benzoylhydrazine has been investigated in Britton-Robinson buffer. The peaks obtained at pH 5 are recommended for the microdetermination of these compounds. The benzoylhydrazine can be obtained with high degrees of accuracy with an experimental detection limit of 4 × 10−6 M in simple aqueous and aqueous ethanol mixtures. 相似文献