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101.
A. Sarkar S. K. Ray A. Dhar D. Bhattacharya K. L. Chopra 《Journal of Superconductivity》1996,9(2):217-222
Thin films of YBa2Cu3O7– (YBCO) have been grownin situ on silicon single-crystal (100) substrate by using SrTiO3 as a buffer layer. The deposition has been carried out by on-axis rf magnetron sputtering method. The deposition condition have been optimized by studying the plasma characteristics and correlating them with the superconducting performance of the film. Films deposited at substrate temperature in the range of 680–700°C from stoichiometric YBCO targets in an argon + oxygen mixture (31) are superconducting and showc-axis epitaxy. Compositional confirmation has been carried out using Rutherford backscattering. Scanning tunneling microscopy of the films reveal formation of well-defined layered structure with some defects in the initial stages ofin situ growth of the films. Films grown on SrTiO3 substrates have excellent crystalline quality (XRD), transition temperatureT
c0=81 K and the critical current densityJ
c
>2×105 A/cm2 for unpatterned films at 77 K. On silicon substrates using buffer layers thein situ deposited YBCO films shows a higher transition width andT
c0 is also slightly less (71 K). 相似文献
102.
Subramanian Baskaran Anandan Mohanbabu Veerappan Saminathan Panneerselvam Murugapandiyan Wasim Mohammed Radhakrishnan Saravana Kumar Pechimuthu Praveen Verma Yogesh Kumar Vivekanandhan Subash Navaneethan Raju Elamurugan 《Journal of Electronic Materials》2020,49(7):4091-4099
Journal of Electronic Materials - This paper presents a systematic study of Al0.23Ga0.77N/GaN/AlxGa1?xN double-heterojunction high-electron-mobility transistors (DH-HEMTs) with a boron-doped... 相似文献
103.
Sharma Shashibhushan Roy Sanjay Dhar Kundu Sumit 《Wireless Personal Communications》2020,110(4):2045-2064
Wireless Personal Communications - In this paper, we analyze the secrecy outage probability (SOP) of a cognitive cooperative radio network in a two-way communication in which two secondary source... 相似文献
104.
Aquib Mustafa Narendra K. Dhar Nishchal K Verma 《IEEE/CAA Journal of Automatica Sinica》2020,7(1):307-314
In this paper, an event-triggered sliding mode control approach for trajectory tracking problem of nonlinear input affine system with disturbance has been proposed. A second order robotic manipulator system has been modeled into a general nonlinear input affine system. Initially, the global asymptotic stability is ensured with conventional periodic sampling approach for reference trajectory tracking. Then the proposed approach of event-triggered sliding mode control is discussed which guarantees semi-global uniform ultimate boundedness. The proposed control approach guarantees non-accumulation of control updates ensuring lower bounds on inter-event triggering instants avoiding Zeno behavior in presence of the disturbance. The system shows better performance in terms of reduced control updates, ensures system stability which further guarantees optimization of resource usage and cost. The simulation results are provided for validation of proposed methodology for tracking problem by a robotic manipulator. The number of aperiodic control updates is found to be approximately 44% and 61% in the presence of constant and time-varying disturbances respectively. 相似文献
105.
Shashibhushan Sharma Sanjay Dhar Roy Sumit Kundu 《International Journal of Communication Systems》2019,32(7)
In this paper, two underlay based cognitive cooperative radio networks, each with one secondary source (SS), one secondary destination (SD), N untrusted secondary amplify and forward relays (USAFRs), one primary transmitter, and one primary receiver (PU‐RX), are considered for evaluating the secrecy performance. The SS sends the information to the SD in two time slots via multiple USAFRs in the absence of direct link between SS and SD. In the first time slot, SS and SD transmit the message and jamming signal to multiple USAFRs, respectively. In the second slot, a selected USAFR amplifies and forwards the combined received signals to the SD. The transmit powers of the secondary nodes are chosen so as to maintain the overall interference at PU‐RX below a specified limit. The transmit power of a selected USAFR is derived using the harvested energy from the RF signals of SS and SD. Two network scenarios of eavesdropping by USAFRs are studied: in one case, all USAFRs eavesdrop; while in the second case, only the selected USAFR eavesdrops the message during forwarding of the signal and power is allocated to secondary nodes on the basis of outage threshold of primary network. We investigate the secrecy outage probability (SOP) in both of the networks under several physical parameters. Analytical framework for evaluating SOP for both the cases are given while SOP in single integration form is given for the second case. MATLAB simulation results are presented for both the cases. 相似文献
106.
Some benzimidazoles were designed and synthesized by a new route using nano-SiO2 as a highly efficient catalyst. Synthesized compounds were characterized by 1H and 13C-NMR spectral studies. The significant features of this nanocatalyst are high yield of products, short reaction times, green reaction media and a vast range of substrates usage. Proton and 13C chemical shift of the synthesized compounds were calculated. To further confirm the compound formation single crystal XRD analysis was made and discussed for 2-(1H-benzimidazol-2-yl) phenol (1). The crystal packing features four π– π stacking interactions involving the imidazole ring, fused benzene ring and attached benzene ring system [centroid–centroid distances = 3.6106 (17), 3.6108 (17), 3.6666 (17) and 3.6668 (17) Å]. Optimization of compound 1 was performed by DFT at B3LYP/6-31G (d, p) using Gaussian-03. All these XRD data are in good agreement with the theoretical values. However, from the theoretical values it is found that most of the optimized bond lengths, bond angles and dihedral angles are slightly higher than the XRD values. 相似文献
107.
This work deals with dispersion of pollutants emitted from a continuous point source at ground level in unsteady situations under three atmospheric conditions: neutral, stable and unstable atmospheres at low inversion heights. The ground level concentration (g.l.c.) profiles are obtained and allow interpretation when comparative studies are made. 相似文献
108.
ABSTRACT This paper presents an approach to improve overall blasting efficiency in an iron ore mine. The problems existing in the mines were oversize fragmentation, severe backbreak, frequent secondary drilling and blasting operations, sloping bench faces and irregular bench profiles. Thorough analysis of the blasting practices and results was done in the search of key parameters affecting blasting efficiency. The parameters were burden, stemming length, delay period between the rows, placement of booster charge, booster ratio and firing pattern. Optimum blast geometry was evolved by making proper adjustments of the above parameters during trial blasts. 相似文献
109.
Wireless Networks - Energy efficient scheduling of sensor nodes is one of the most efficient techniques to extend the lifetime of the wireless sensor networks (WSNs). Instead of activating all the... 相似文献
110.
Silicon - Cerium loaded CuO nanoparticles (Ce-CuO NPs) were successfully synthesized by a precipitation-thermal decomposition method. The synthesized Ce-CuO NPs were used as a nanocatalyst for the... 相似文献