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121.
Using the combustion synthesis, CaYAl3O7:Er3+ phosphor powders co-doped with Yb3+ have been prepared at low temperatures (550 °C) in a few minutes. Formation of the compound was confirmed by X-ray powder diffraction. Near-infrared to visible upconversion fluorescence emission in the Er3+ doped CaYAl3O7 phosphor powder has been observed. The effect of co-doping with triply ionized ytterbium in the CaYAl3O7:Er3+ phosphor has been studied and the process involved is discussed. 相似文献
122.
We continuously measure the state of a superconducting quantum bit coupled to a microwave readout cavity by using a fast, ultralow-noise parametric amplifier. This arrangement allows us to observe quantum jumps between the qubit states in real time, and should enable quantum error correction and feedback--essential components of quantum information processing. 相似文献
123.
Zhongkui Tan Vijay Patel Konstantin K. Likharev Dong Su Yimei Zhu 《Applied Physics A: Materials Science & Processing》2011,103(2):293-300
We have studied resistive bistability (memory) effects in junctions based on metal oxides, with a focus on sample-to-sample
reproducibility, which is necessary for the use of such junctions as crosspoint devices of hybrid CMOS/nanoelectronic circuits.
Few-nm-thick layers of NbO
x
, CuO
x
and TiO
x
have been formed by thermal and plasma oxidation, at various deposition and oxidation conditions, both with and without rapid
thermal post-annealing. The resistive bistability effect has been observed for all these materials, with particularly high
endurance (over 103 switching cycles) obtained for single-layer TiO2 junctions, and the best reproducibility reached for multi-layer junctions of the same material. Fabrication optimization
has allowed us to improve the OFF/ON resistance ratio to about 103, but the sample-to-sample reproducibility is so far lower than that required for large-scale integration. 相似文献
124.
In the present paper, we deal with the complex Szasz-Durrmeyer operators and study Voronovskaja type results with quantitative estimates for these operators attached to analytic functions of exponential growth on compact disks. Also, the exact order of approximation is found. 相似文献
125.
A novel size dependent FCC (face-centered-cubic) → HCP (hexagonally-closed-pack) phase transformation and stability of an initial FCC zirconium nanowire are studied. FCC zirconium nanowires with cross-sectional dimensions <20 Å are found unstable in nature, and they undergo a FCC → HCP phase transformation, which is driven by tensile surface stress induced high internal compressive stresses. FCC nanowire with cross-sectional dimensions >20 Å, in which surface stresses are not enough to drive the phase transformation, show meta-stability. In such a case, an external kinetic energy in the form of thermal heating is required to overcome the energy barrier and achieve FCC → HCP phase transformation. The FCC-HCP transition pathway is also studied using Nudged Elastic Band (NEB) method, to further confirm the size dependent stability/metastability of Zr nanowires. We also show size dependent critical temperature, which is required for complete phase transformation of a metastable-FCC nanowire. 相似文献
126.
127.
Mukund G. Kulkarni Sanjay W. Chavhan Mayur P. Desai Yunnus B. Shaikh Dnyaneshwar D. Gaikwad Attrimuni P. Dhondge Ajit S. Borhade Vijay B. Ningdale Deekshaputra R. Birhade Nagorao R. Dhatrak 《Tetrahedron letters》2010,51(34):4494-6381
Application of Wittig olefination-Claisen rearrangement protocol for the short synthesis of furo[2,3-b]indoles is described. 相似文献
128.
Vijay K. Agrawal Shahnaz Bano Keshav C. Mathur Padmakar V. Khadikar 《Journal of Chemical Sciences》2000,112(2):137-146
The paper gives a brief account of the recently introduced Szeged index (Sz). Using this index antitubercular activities of
N-2,4-difluorophenyl quinolones are subjected to quantitative structure-activity relationship analysis. The potential of Sz
related to the Wiener index (W) is critically discussed. In addition, Huckel molecular orbital energies:E
HOMO,E
LUMO andE
total were also used for comparing and modelling antitubercular activities of the quinolones. The results, based on univariate
as well as multivariate regressions, have shown that W, SZ andE
total give better results and that the correlations improve in multivariate regression analyses. 相似文献
129.
130.
Consider the polyhedron represented by the dual of the LP formulation of the maximums–t flow problem. It is well known that the vertices of this polyhedron are integral, and can be viewed ass–t cuts in the given graph. In this paper we show that not alls–t cuts appear as vertices, and we give a characterization. We also characterize pairs of cuts that form edges of this polyhedron. Finally, we show a set of inequalities such that the corresponding polyhedron has as its vertices alls–t cuts.Work done at the Department of Computer Science and Engineering, Indian Institute of Technology, Delhi, India. 相似文献