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21.
Sunil K. Singhal Veeresh Kumar K. Stalin Amit Choudhary Satish Teotia Gade B. Reddy Rakesh B. Mathur Surinder P. Singh Renu Pasricha 《Particle & Particle Systems Characterization》2013,30(5):445-452
Synergetic cooperation of individual components of the nanocomposites (NCs) is responsible for their novel properties that lead to various technological applications. A simple chemical process depicting the deposition of functionalized gold nanoparticles on the surface of boron nitride nanosheets (BNNSs) in solution is reported. The structure, chemical composition, and optical properties of nanosheets are systematically studied. The deposition of Au nanoparticles on BNNS (BNNSAu) results in plasmonic band modulation, thus altering the optoelectronic properties of BNNSs. The intense surface plasmon absorption band of BNNSAu is narrowed and red‐shifted relative to the absorption band of as synthesized monometallic BNNSs. The observations reflect the strong interfacial interaction between BNNS and Au nanoparticles. This approach constitutes a basis for a simple process leading to the preparation of functionalized BNNSs and their utilization as nanoscale templates for assembly and integration with other nanoscale materials for futuristic optoelectronic devices. 相似文献
22.
Recently there has been increased interest in the development of high-level architectural synthesis tools targeting power optimization. In this paper, we first present an overview of the various architecture synthesis tasks and analyze their influence on power consumption. A survey of previously proposed techniques is given, and areas of opportunity are identified. We next propose a new architecture synthesis technique for low-power implementation of real-time applications. The technique uses algorithm partitioning to preserve locality in the assignment of operations to hardware units. Preserving locality results in more compact layouts, reduced usage of long high-capacitance buses, and reduced power consumption in multiplexors and buffers. Experimental results show reductions in bus and multiplexor power of up to 80% and 60%, respectively, resulting in 10–25% reduction in total power. 相似文献
23.
Renu Tripathi G.S. Pati M. Messall K. Salit M.S. Shahriar 《Optics Communications》2006,266(2):604-608
We report on experimental observation of electromagnetically induced transparency and slow-light (vg ≈ c/607) in atomic sodium vapor, as a potential medium for a recently proposed experiment on slow-light enhanced relative rotation sensing [Shahriar et al. Phys. Rev. Lett. (submitted for publication), http://arxiv.org/abs/quant-ph/0505192.]. We have performed an interferometric measurement of the index variation associated with a two-photon resonance to estimate the dispersion characteristics of the medium that are relevant to the slow-light based rotation sensing scheme. We also show that the presence of counter-propagating pump beams in an optical Sagnac loop produces a backward optical phase conjugation beam that can generate spurious signals, which may complicate the measurement of small rotations in the slow-light enhanced gyroscope. We identify techniques for overcoming this constraint. Conclusions reached from the results presented here will pave the way for designing and carrying out an experiment that will demonstrate the slow-light induced enhancement of rotation sensing. 相似文献
24.
Reactions of copper(I) halides (Cl, Br, I) with 1‐methyl‐1, 3‐imidazoline‐2‐thione (mimzSH) in 1 : 2 molar ratio yielded sulfur‐bridged dinuclear [Cu2X2(μ‐S‐mimzSH)2(η1‐S‐mimzSH)2] (X = I, 1 , Br, 2 ; Cl, 3 ) complexes. Copper(I) iodide with 1,3‐imidazoline‐2‐thione (imzSH2) and Ph3P in 1 : 1 : 1 molar ratio has also formed a sulfur‐bridged dinuclear [Cu2I2(μ‐S‐imzSH2)2(PPh3)2] ( 4 ) complex. The central Cu(μ‐S)2Cu cores form parallelograms with unequal Cu–S bond distances {2.324(2), 2.454(3) Å} ( 1 ); {2.3118(6), 2.5098(6) Å} ( 2 ); {2.3075(4), 2.5218(4) Å} ( 3 ); {2.3711(8), 2.4473(8) Å} ( 4 ). The Cu···Cu separations, 2.759–2.877Å in complexes 1 – 3 are much shorter than 3.3446Å in complex 4 . The weak intermolecular interactions {H2CH···S# ( 2 ); CH···Cl# ( 3 ); NH···I# ( 4 )} between dimeric units in complexes 2 – 4 lead to the formation of linear 1D polymers. 相似文献
25.
The synthesis of the cis and trans forms of the cyclic dipeptide of O-diazoacetyl-DL-serine is described. 相似文献
26.
M.H. Nurmawati R. Renu P.K. Ajikumar S. Sindhu F.C. Cheong C.H. Sow S. Valiyaveettil 《Advanced functional materials》2006,16(18):2340-2345
Micro‐ and nanostructuring of conjugated polymers are of critical importance in the fabrication of molecular electronic devices as well as photonic and bandgap materials. The present report delineates the single‐step self‐organization of highly ordered structures of functionalized poly(p‐phenylene)s without the aid of either a controlled environment or expensive fabrication methodologies. Microporous films of these polymers, with a honeycomb pattern, were prepared by direct spreading of the dilute polymer solution on various substrates, such as glass, quartz, silicon wafer, indium tin oxide, gold‐coated mica, and water, under ambient conditions. The polymeric film obtained from C12PPPOH comprises highly periodic, defect‐free structures with blue‐light‐emitting properties. It is expected that such microstructured, conjugated polymeric films will have interesting applications in photonic and optoelectronic devices. The ability of the polymer to template the facile micropatterning of nanomaterials gives rise to hybrid films with very good spatial dispersion of the carbon nanotubes. 相似文献
27.
Mono-, di-, tri- and tetra-substituted epoxides undergo facile deoxygenation yielding olefins when treated with lithium in tetrahydrofuran. Aliphatic epoxides yield olefins with the same stereochemistry as the parent compound. 相似文献
28.
It is shown by Rao and Rao that certain geometric properties characterize the line graph of a BIB design with parameters b, v, r, k, 1, provided r - 2k + 1 < 0. If r = k + 1, and , a characterization of the line graph of a finite affine plane is obtained. If r - 2k + 1 = 0, the only possible value for k is 2 and consequently r = k + 1 resulting in the case of the line graph of a finite affine plane. It is shown here that if r = k + 1 and k = 2, there are exactly seven other non-isomorphic graphs with those properties which are not the line graph of a finite affine plane and these are the only cubic graphs on twelve vertices with no quadrilaterals. 相似文献
29.
Jung Woo Lee Ravindranath Viswan Yoon Jeong Choi Yeob Lee Se Yun Kim Jaehun Cho Younghun Jo Jeung Ku Kang 《Advanced functional materials》2009,19(14):2213-2218
Using conventional methods to synthesize magnetic nanoparticles (NPs) with uniform size is a challenging task. Moreover, the degradation of magnetic NPs is an obstacle to practical applications. The fabrication of silica‐shielded magnetite NPs on carbon nitride nanotubes (CNNTs) provides a possible route to overcome these problems. While the nitrogen atoms of CNNTs provide selective nucleation sites for NPs of a particular size, the silica layer protects the NPs from oxidation. The morphology and crystal structure of NP–CNNT hybrid material is investigated by transmission electron microscopy (TEM) and X‐ray diffraction. In addition, the atomic nature of the N atoms in the NP–CNNT system is studied by near‐edge X‐ray absorption fine structure spectroscopy (nitrogen K‐edge) and calculations of the partial density of states based on first principles. The structure of the silica‐shielded NP–CNNT system is analyzed by TEM and energy dispersive X‐ray spectroscopy mapping, and their magnetism is measured by vibrating sample and superconducting quantum interference device magnetometers. The silica shielding helps maintain the superparamagnetism of the NPs; without the silica layer, the magnetic properties of NP–CNNT materials significantly degrade over time. 相似文献
30.
Renu Bala Poonam Kumari Sumit Sood Harshita Phougat Anil Kumar Karan Singh 《Journal of heterocyclic chemistry》2019,56(6):1787-1793
The conversion of aldehydes into carboxylic acids using oxidizing agents is a common protocol in transformation chemistry. An efficient oxidation strategy of transformation of pyrazole‐4‐aldehydes to the corresponding acids using vanadium catalysts in the presence of 30% H2O2 as an oxidant is described. The catalytic technology was successfully applied to a range of various 4‐formylpyrazoles, and plausible mechanism is also discussed. 相似文献