排序方式: 共有116条查询结果,搜索用时 140 毫秒
71.
Loganathan K. Mohana K. Mohanraj M. Sakthivel P. Rajan S. 《Journal of Thermal Analysis and Calorimetry》2021,144(5):1935-1947
Journal of Thermal Analysis and Calorimetry - The current article deals with heat transfer and entropy generation analysis using Cattaneo–Christov heat flux (CCHF) for a flow of third grade... 相似文献
72.
Machhindra Gund S. Mohana Roopan Fazlur-Rahman Nawaz Khan Jong Sung Jin Rajesh Kumar A. Sudheer Kumar 《Research on Chemical Intermediates》2012,38(3-5):1111-1118
An efficient and regioselective O-alkylation of amides with a variety of electrophiles in the presence of silver nanoparticles is reported as part of our recent research on building blocks for synthesis of natural products. The nano-silver catalyst initiates O-alkylation of the amides by heteroalkyl halides. Reaction of equimolar 3-acetyl-6-chloro-4-phenylquinolin-2(1H)-one and 2-chloro-3-(chloromethyl)quinolines in the presence of silver nanoparticles in DMSO solution under reflux condition leads to the formation of 1-{1-[2-chloroquinolin-3-yl)methoxy]-6-chloro-4-phenylquinolin-3-yl}ethanones. 相似文献
73.
Let X be a Banach space, 2x\? the nonempty subsets of X,J = [o,a]?R and F:J×X→2x\? a multivalued map. We consider U′ ? F(t,u) a.e. on J, u(o) = Xp ? X. A solution of (1) is understood to be a.e. differentiable with u′ Bochner integrable over J such that u(t) =X0 + ∫0 t u′(s)ds on J and u′(t)?F(t,u(t)) a.e. Under appropriate conditions on F the set S of solutions to (1) is compact ≠ ? in CX (J), the space of continuous v : J → X with ∣v∣0 = max∣v(t)∣. We concentrate on maps F with F(t,.) upper semicontinuous andshow that S is connected or even a compact Rδ in the sense of Borsuk. This is interesting in itself, but also in connection with the multivalued Poincare map in case F is periodic in time. 相似文献
74.
Mudiam MK Jain R Dua VK Singh AK Sharma VP Murthy RC 《Analytical and bioanalytical chemistry》2011,401(5):1695-1701
A simple and rapid analytical method based on in-matrix ethyl chloroformate (ECF) derivatization has been developed for the quantitative determination of bisphenol-A (BPA) in milk and water samples. The samples containing BPA were derivatised with ECF in the presence of pyridine for 20 s at room temperature, and the non-polar derivative thus formed was extracted using polydimethylsiloxane solid-phase microextraction (SPME) fibres with thicknesses of 100 μm followed by analysis using gas chromatography-mass spectrometry. Three alkyl chloroformates (methyl, ethyl and isobutyl chloroformate) were tested for optimum derivatisation yields, and ECF has been found to be optimum for the derivatisation of BPA. Several parameters such as amount of ECF, pyridine and reaction time as well as SPME parameters were studied and optimised in the present work. The limit of detection for BPA in milk and water samples was found to be 0.1 and 0.01 μg L(-1), respectively, with a signal-to-noise ratio of 3:1. The limit of quantitation for BPA in milk and water was found to be 0.38 and 0.052 μg L(-1), respectively, with a signal-to-noise ratio of 10:1. In conclusion, the method developed was found to be rapid, reliable and cost-effective in comparison to silylation and highly suitable for the routine analysis of BPA by various food and environmental laboratories. 相似文献
75.
Mahesh Kumar Basanta Roul Mohana K. Rajpalke Thirumaleshwara N. Bhat A.T. Kalghatgi S.B. Krupanidhi 《Current Applied Physics》2013,13(1):26-30
The temperature dependent electrical transport behavior of n–n InGaN/Si heterostructures grown by plasma-assisted MBE was studied. Structural characteristics of the as-grown InGaN epilayers were evaluated high resolution X-ray diffraction and composition of InGaN was estimated from photoluminescence spectra using standard Vegard's law. Current density–voltage plots (J–V–T) revealed that the ideality factor (η) and Schottky barrier height (SBH) (Φb) are temperature dependent and the incorrect values of the Richardson's constant (A7) produced, suggests an inhomogeneous barrier at the heterostructure interface. The higher value of the ideality factor compared to the ideal value and its temperature dependence suggest that the current transport is mainly dominated by thermionic field emission. 相似文献
76.
Ionics - The inhibition ability of three newly synthesized piperidine sulphonamides toward the mild steel (MS) corrosion was investigated using mass loss and electrochemical techniques. The... 相似文献
77.
Basanta Roul Thirumaleshwara N. Bhat Mohana K. Rajpalke A.T. Kalghatgi 《Solid State Communications》2011,151(20):1420-1423
The electrical transport properties of InN/GaN heterostructure based Schottky junctions were studied over a wide temperature range of 200-500 K. The barrier height and the ideality factor were calculated from current-voltage (I-V) characteristics based on thermionic emission (TE), and found to be temperature dependent. The barrier height was found to increase and the ideality factor to decrease with increasing temperature. The observed temperature dependence of the barrier height indicates that the Schottky barrier height is inhomogeneous in nature at the heterostructure interface. Such inhomogeneous behavior was modeled by assuming the existence of a Gaussian distribution of barrier heights at the heterostructure interface. 相似文献
78.
Heba Alaa Hosiny Abd Elhameed Ditta Ungor Nra Igaz Mohana Krishna Gopisetty Mnika Kiricsi Edit Csap Bla Gyurcsik 《Macromolecular bioscience》2020,20(7)
Over the past decade, search for novel materials for nucleic acid delivery has prompted a special interest in polymeric nanoparticles (NPs). In this study, the biological applicability of a water‐soluble cationic lipopolymer (WSLP) obtained by the modification of high molecular weight branched poly(ethylenimine) (PEI) with cholesteryl chloroformate is characterized and assessed for better cellular membrane permeability. To test the delivery efficiency of the produced lipopolymer, plasmid DNA (pDNA) encoding the enhanced green fluorescent protein and WSLP are mixed at different charge ratios. WSLP and WSLP/pDNA complexes are characterized by dynamic and static light scattering, particle charge detection, scanning electron microscopy, and transmission electron microscopy. The pDNA loading of WSLP is also verified by agarose gel electrophoresis. Cytotoxicity of PEI, WSLP, and of WSLP/pDNA is evaluated on human A549 and HeLa cells. A remarkable dependence of the toxicity on the dose, cholesterylation, and charge ratio is detected. Transfection is monitored by flow cytometry and by fluorescence microscopy. Importantly, cholesterylation decreases the toxicity of the polymer, while promoting high transfection efficiency in both cell lines. This work indicates a possible optimization mode of the high molecular weight PEI‐based WSLP rendering it a promising candidate for gene delivery. 相似文献
79.
Ratna Prasad V. Atluri K. Mohana Rao A. V. S. S. K. S. Gupta 《International Journal of Polymer Analysis and Characterization》2013,18(1):30-39
The main objective of this article is to introduce a new natural fiber as a reinforcement in polymers for making composites for lightweight applications. The extraction of golden cane (Chrysalidocarpus lutescens) fiber and the mechanical properties of the fiber-reinforced polyester composites are described. The composites were formulated up to a maximum volume fraction of 0.43, resulting in a mean tensile strength and modulus of 2.13 and 2.26 times and mean flexural strength and modulus of 1.94 and 2.89 times greater than those of plain polyester, respectively, at a higher volume fraction of 0.43. The work of fracture in impact is measured to be 358 J/m. The results of this study indicate that golden cane fibers have potential as reinforcing fillers in plastics in order to produce inexpensive materials with high toughness. 相似文献
80.
Aakash D. Nidhankar Goudappagouda Divya S. Mohana Kumari Shailendra Kumar Chaubey Rashmi Nayak Rajesh G. Gonnade G. V. Pavan Kumar Retheesh Krishnan Sukumaran Santhosh Babu 《Angewandte Chemie (International ed. in English)》2020,59(31):13079-13085
Room‐temperature phosphorescence of metal and heavy atom‐free organic molecules has emerged as an area of great potential in recent years. A rational design played a critical role in controlling the molecular ordering to impart efficient intersystem crossing and stabilize the triplet state to achieve room‐temperature ultralong phosphorescence. However, in most cases, the strategies to strengthen phosphorescence efficiency have resulted in a reduced lifetime, and the available nearly degenerate singlet‐triplet energy levels impart a natural competition between delayed fluorescence and phosphorescence, with the former one having the advantage. Herein, an organic helical assembly supports the exhibition of an ultralong phosphorescence lifetime. In contrary to other molecules, 3,6‐phenylmethanone functionalized 9‐hexylcarbazole exhibits a remarkable improvement in phosphorescence lifetime (>4.1 s) and quantum yield (11 %) owing to an efficient molecular packing in the crystal state. A right‐handed helical molecular array act as a trap and exhibits triplet exciton migration to support the exceptionally longer phosphorescence lifetime. 相似文献