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121.
paper presents a novel approach to model and represent chipless radio-frequency identification (RFID) frequency signatures. The approach involves the geometrical representation of chipless RFID frequency signatures in a signal space. A small set of orthonormal basis functions is derived using singular value decomposition in order to represent the 2 b possible tag signatures of a b-bit chipless tag. Each tag signature is represented as a point in an L-dimensional signal space, and minimum distance detection is used to extract the information bit sequence of the tag. Detection error probability is also examined through analytical derivations and Monte Carlo simulation. A set of 3-bit tags were fabricated to validate the approach. Experimental results show that the new approach is capable of accurately detecting information contained in chipless RFID tags. This approach offers a solid mathematical framework for developing novel detection methods for chipless tags. 相似文献
122.
123.
P.-Y. Chan M. Gogna E. Suarez F. Al-Amoody S. Karmakar B. I. Miller E. K. Heller J. E. Ayers F. C. Jain 《Journal of Electronic Materials》2013,42(11):3259-3266
An indium gallium arsenide quantum-dot-gate field-effect transistor using Zn0.95Mg0.05S as the gate insulator is presented in this paper, showing three output states which can be used in multibit logic applications. The spatial wavefunction switching effect in this transistor has been investigated, and modeling simulations have shown supporting evidence that additional output states can be achieved in one transistor. 相似文献
124.
125.
E. Suarez M. Gogna F. Al-Amoody S. Karmakar J. Ayers E. Heller F. Jain 《Journal of Electronic Materials》2010,39(7):903-907
This paper presents preliminary data on quantum dot gate nonvolatile memories using nearly lattice-matched ZnS/Zn0.95Mg0.05S/ZnS tunnel insulators. The GeO
x
-cladded Ge and SiO
x
-cladded Si quantum dots (QDs) are self-assembled site-specifically on the II–VI insulator grown epitaxially over the Si channel
(formed between the source and drain region). The pseudomorphic II–VI stack serves both as a tunnel insulator and a high-κ dielectric. The effect of Mg incorporation in ZnMgS is also investigated. For the control gate insulator, we have used Si3N4 and SiO2 layers grown by plasma- enhanced chemical vapor deposition. 相似文献
126.
Tirtha Som Basudeb Karmakar 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2010,75(2):640-646
Dichroic Sm3+: Au-antimony glass nanocomposites are synthesized in a new reducing glass (dielectric) matrix (mol%) K2O–B2O3–Sb2O3 (KBS) by a single-step melt-quench technique involving selective thermochemical reduction. X-ray diffraction (XRD) and selected area electron diffraction (SAED) results indicate that Au0 nanoparticles are grown along the (2 0 0) plane direction. The transmission electron microscopic (TEM) image reveals the elliptical Au0 nanoparticles having major axis range 12–17 nm. Dichroic behavior is due to elliptical shape of Au0 nanoparticles of aspect ratio ~1.2. Au0 NPs of concentration of 0.03 wt% (4.1 × 1018 atoms/cm3) drastically enhances the intensity (~7-folds) of electric dipole 4G5/2 → 6H9/2 red transition (636 nm) of Sm3+ ions and then attenuates with further increase in Au0 concentration. The magnetic dipole 4G5/2 → 6H5/2 green (566 nm) and 4G5/2 → 6H7/2 orange (602 nm) transitions remain almost unaffected by presence of nano Au0. Local field enhancement (LFE) induced by Au0 SPR and energy transfer (ET) from fluorescent Au0 → Sm3+ ions are found to be responsible for the enhancement while reverse ET from Sm3+ → Au0 and optical re-absorption due to Au0 SPR for attenuation. 相似文献
127.
Nd3+-doped precursor glass in the K2O–SiO2–Y2O3–Al2O3 (KSYA) system was prepared by the melt-quench technique. The transparent Y3Al5O12 (YAG) glass–ceramics were derived from this glass by a controlled crystallization process at 750 °C for 5–100 h. The formation of YAG crystal phase, size and morphology with progress of heat-treatment was examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and Fourier transformed infrared reflectance spectroscopy (FT-IRRS). The crystallite sizes obtained from XRD are found to increase with heat-treatment time and vary in the range 25–40 nm. The measured photoluminescence spectra have exhibited emission transitions of 4F3/2 → 4IJ (J = 9/2, 11/2 and 13/2) from Nd3+ ions upon excitation at 829 nm. It is observed that the photoluminescence intensity and excited state lifetime of Nd3+ ions decrease with increase in heat-treatment time. The present study indicates that the incorporation of Nd3+ ions into YAG crystal lattice enhance the fluorescence performance of the glass–ceramic nanocomposites. 相似文献
128.
Qiao B Zepf M Borghesi M Dromey B Geissler M Karmakar A Gibbon P 《Physical review letters》2010,105(15):155002
A new ion radiation-pressure acceleration regime, the "leaky light sail," is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to stabilize the acceleration of the light ion component, supplementing the latter with an excess of electrons leaked from those associated with the heavy ions to avoid Coulomb explosion. It is shown by 2D particle-in-cell simulations that a monoenergetic proton beam with energy 18 MeV is produced by circularly polarized lasers at intensities of just 101? W/cm2. 100 MeV proton beams are obtained by increasing the intensities to 2 × 102? W/cm2. 相似文献
129.
Bimodal Functionality in a Porous Covalent Triazine Framework by Rational Integration of an Electron‐Rich and ‐Deficient Pore Surface 下载免费PDF全文
Avishek Karmakar Amrit Kumar Abhijeet K. Chaudhari Partha Samanta Aamod V. Desai Rajamani Krishna Dr. Sujit K. Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4931-4937
A porous covalent triazine framework (CTF) consisting of both an electron‐deficient central triazine core and electron‐rich aromatic building blocks is reported. Taking advantage of the dual nature of the pore surface, bimodal functionality has been achieved. The electron deficiency in the central core has been utilized to address one of the pertinent problems in chemical industries, namely separation of benzene from its cyclic saturated congener, that is, cyclohexane. Also, by virtue of the electron‐rich aromatic rings with Lewis basic sites, aqueous‐phase chemical sensing of a nitroaromatic compound of highly explosive nature (2,4,6‐trinitrophenol; TNP) has been achieved. The present compound supersedes the performance of previously reported COFs in both the aspects. Notably, this reports the first example of pore‐surface engineering leading to bimodal functionality in CTFs. 相似文献
130.
Santanu MandalTapan Kumar Karmakar Anupam GhoshMichel Fleck Debasis Bandyopadhyay 《Polyhedron》2011,30(5):790-795
Five mononuclear complexes of manganese(II) of a group of the general formula, [MnL(NCS)2] where the Schiff base L = N,N′-bis[(pyridin-2-yl)ethylidene]ethane-1,2-diamine (L1), (1); N,N′-bis[(pyridin-2-yl)benzylidene]ethane-1,2-diamine (L2), (2); N,N′-bis[(pyridin-2-yl)methylidene]propane-1,2-diamine (L3), (3); N,N′-bis[(pyridin-2-yl)ethylidene]propane-1,2-diamine (L4), (4) and N,N′-bis[(pyridin-2-yl)benzylidene]propane-1,2-diamine (L5), (5) have been prepared. The syntheses have been achieved by reacting manganese chloride with the corresponding tetradentate Schiff bases in presence of thiocyanate in the molar ratio of 1:1:2. The complexes have been characterized by IR spectroscopy, elemental analysis and other physicochemical studies, including crystal structure determination of 1, 2 and 4. Structural studies reveal that the complexes 1, 2 and 4 adopt highly distorted octahedral geometry. The antibacterial activity of all the complexes and their respective Schiff bases has been tested against Gram(+) and Gram(−) bacteria. 相似文献