排序方式: 共有67条查询结果,搜索用时 15 毫秒
61.
Isaac Premkumar I. J. Prabhu A. Vijayan V. Godwin Antony A. Venkatesh R. 《Journal of Thermal Analysis and Calorimetry》2020,142(4):1457-1467
Journal of Thermal Analysis and Calorimetry - Shallow reentrant piston (SRP) and deep cylindrical piston (DCP) geometries were designed by modifying the compression ratio of an engine with baseline... 相似文献
62.
Rishabh Gupta Supriya Sahoo Swati Deswal Premkumar Kothavade Prashant Dixit Dr. Jan K. Zaręba Dr. Kadhiravan Shanmuganathan Prof. Dr. Ramamoorthy Boomishankar 《化学:亚洲杂志》2021,16(24):4122-4129
Organic ferroelectrics due to their low cost, easy preparation, light weight, high flexibility and phase stability are gaining tremendous attention in the field of portable electronics. In this work, we report the synthesis, structure and ferroelectric behavior of a two-component ammonium salt 2 , containing a bulky [Bn(4-BrBn)NMe2]+ (Bn=benzyl and 4-BrBn=4-bromobenzyl) cation and tetrahedral (BF4)− anion. The structural analysis revealed the presence of rich non-classical C−H⋅⋅⋅F and C−H⋅⋅⋅Br interactions in this molecule that were quantified by Hirshfeld surface analysis. The polarization (P) vs. electric field (E) hysteresis loop measurements on 2 gave a remnant polarization (Pr) of 14.4 μC cm−2 at room temperature. Flexible polymer composites with various (5, 10, 15 and 20) weight percentages (wt%) of 2 in thermoplastic polyurethane (TPU) were prepared and tested for mechanical energy harvesting applications. A notable peak-to-peak output voltage of 20 V, maximum current density of 1.1 μA cm−2 and power density of 21.1 μW cm−2 were recorded for the 15 wt% 2 -TPU composite device. Furthermore, the voltage output generated from this device was utilized to rapidly charge a 100 μF capacitor, with stored energies and measured charges of 156 μJ and 121.6 μC, respectively. 相似文献
63.
Reineri F Viale A Ellena S Alberti D Boi T Giovenzana GB Gobetto R Premkumar SS Aime S 《Journal of the American Chemical Society》2012,134(27):11146-11152
(15)N-Propargylcholine has been synthesized and hydrogenated with para-H(2). Through the application of a field cycling procedure, parahydrogen spin order is transferred to the (15)N resonance. Among the different isomers formed upon hydrogenation of (15)N-propargylcholine, only the nontransposed derivative contributes to the observed N-15 enhanced emission signal. The parahydrogen-induced polarization factor is about 3000. The precise identification of the isomer responsible for the observed (15)N enhancement has been attained through a retro-INEPT ((15)N-(1)H) experiment. T(1) of the hyperpolarized (15)N resonance has been estimated to be ca. 150 s, i.e., similar to that reported for the parent propargylcholine (144 s). Experimental results are accompanied by theoretical calculations that stress the role of scalar coupling constants (J(HN) and J(HH)) and of the field dependence in the formation of the observed (15)N polarized signal. Insights into the good cellular uptake of the compound have been gained. 相似文献
64.
Rajpal Singh Dr. Thathan Premkumar Dr. Ji‐Young Shin Kurt E. Geckeler Prof. Dr. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(6):1728-1743
Carbon nanotubes constitute a novel class of nanomaterials with potential applications in many areas. The attachment of metal nanoparticles to carbon nanotubes is new way to obtain novel hybrid materials with interesting properties for various applications such as catalysts and gas sensors as well as electronic and magnetic devices. Their unique properties such as excellent electronic properties, a good chemical stability, and a large surface area make carbon nanotubes very useful as a support for gold nanoparticles in many potential applications, ranging from advanced catalytic systems through very sensitive electrochemical sensors and biosensors to highly efficient fuel cells. Here we give an overview on the recent progress in this area by exploring the various synthesis approaches and types of assemblies, in which nanotubes can be decorated with gold nanoparticles and explore the diverse applications of the resulting composites. 相似文献
65.
The crystal structures of different forms of TiO2 and those of BaTiO3, ZnO, SnO2, WO3, CuO, Fe2O3, Fe3O4, ZrO2 and Al2O3 nanoparticles have been deduced by powder X-ray diffraction. Their optical edges have been obtained by UV-visible diffuse reflectance spectra. The photocatalytic activities of these oxides and also those of SiO2 and SiO2 porous to oxidize iodide ion have been determined and compared. The relationships between the photocatalytic activities of the studied oxides and the illumination time, wavelength of illumination, concentration of iodide ion, airflow rate, photon flux, pH, etc., have been obtained. Use of acetonitrile as medium favors the photogeneration of iodine. 相似文献
66.
Santhosh Reddy Naini Subramania Ranganathan Jhillu Singh Yadav A.V.S. Sarma K.V.S. Ramakrishna Ramakrishnan Nagaraj J. Richard Premkumar G. Narahari Sastry 《Tetrahedron letters》2014
The generation of a bihelical (figure of 8) motif has been illustrated by trans opening of EDTAA with l-cystine-di-OMe and d-penicillamine disulfide-di-OMe. In the former case the open cyclic system, arising by cis addition, was secured as a minor product. 相似文献
67.
Y. Murali Mohan Thathan Premkumar Kyungjae Lee Kurt E. Geckeler 《Macromolecular rapid communications》2006,27(16):1346-1354
Summary: This paper describes a simple and facile approach to fabricate well dispersed silver nanoparticles (AgNPs) in poly[N‐isopropylacrylamide‐co‐(sodium acrylate)] hydrogels. The silver nanoparticles formed are spherical in shape with a narrow size distribution in the hydrogel networks in which the nanoparticles are stabilized by the polymer network. Uniformly dispersed silver nanoparticles were obtained with poly[N‐isopropylacrylamide‐co‐[sodium acrylate)] hydrogels, whereas a poly(N‐isopropylacrylamide)/poly(sodium acrylate) IPN gel showed aggregated nanoparticles. It is demonstrated that the hydrogel network structure determines the size and shape of the nanoparticles. These particles are more stable in the gel networks compared to other reduction methods. The hydrogel/silver nanohybrids were well characterized by XRD, UV‐vis spectrometry, scanning electron microscopy and transmission electron microscopy.