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1.
2.
Mark L. Agranovsky E. K. Narayanan 《Proceedings of the American Mathematical Society》2006,134(7):2117-2123
A test for a function to be a solution of an elliptic PDE is given in terms of extensions, as solutions, from the boundaries inside the domains belonging to an isotopic family. It generalizes a result of Ehrenpreis for spheres moved along a straight line.
3.
Srinivasan G. 《物理学报》2006,55(5):2548-2552
讨论了Ni0.8Zn0.2Fe2O4 (NZFO)与锆钛酸铅(PZT)的双层膜结构样品的磁电(ME)效应.NZFO粉料由溶胶-凝胶法制成,再经900℃热压,并高温烧结.在该双层膜中测量到了很强的磁电相互作用.发现横向的磁电效应比纵向效应大一个数量级,并且随NZFO烧结温度的提高而增加.当烧结温度从950℃上升到1380℃时,横向ME电压系数(αE)的最大值变化范围为25.6 mV Am-2≤αE≤199.6 mV Am-2.理论分析显示NZFO-PZT双层膜样品中ME效应源于NZFO与PZT之间相对良好的磁电耦合.
关键词:
镍铁氧体
PZT
热压法
ME效应 相似文献
4.
5.
Songxin Tan Ram M. Narayanan Sunil K. Shetty 《International Journal of Infrared and Millimeter Waves》2005,26(8):1175-1194
There is growing interest in the use of lidar for remote sensing of vegetation owing to the emergence of reliable and rugged lasers and highly sensitive detectors. Lidar remote sensing has a distinct advantage over conventional techniques in vegetation remote sensing due to its capability for three-dimensional characterization of vegetative targets. The Multiwavelength Airborne Polarimetric Lidar (MAPL) system was developed primarily for vegetation remote sensing applications from an airborne platform of up to 1,000 -m altitude. The lidar system has full waveform capture and polarimetric measurement capability at two wavelengths in the near-infrared (1064 nm) and the green (532 nm) spectral regions. This study presents preliminary ground-based lidar reflectance measurements on a variety of deciduous and coniferous trees under fully foliated conditions with a view towards tree species discrimination. Variations in the reflectance characteristics of selected deciduous trees under unfoliated and fully foliated conditions were also investigated. Our study reveals distinct differences in the reflectance characteristics of various trees. 相似文献
6.
N. Srinivasan R.C. Johnson N. Kasthurikrishnan P. Wong R.G. Cooks 《Analytica chimica acta》1997,350(3):128-271
An overview of membrane introduction mass spectrometry (MIMS) is presented and comparisons are made with other direct sample introduction techniques. Special attention is given to the unique advantages and the limitations of newer variants on the MIMS technique, including affinity MIMS, reverse-phase and trap MIMS. The salient features of the interfaces used in MIMS are summarized and the various membrane materials commonly used are delineated. The applicability of MIMS is illustrated via discussion of
- 1. (i) bioreactor monitoring (represented by yeast fermentation),
- 2. (ii) environmental monitoring (illustrated by analysis of contaminated ground water samples) and
- 3. (iii) on-line chemical reaction monitoring (exemplified by the photolysis of aryl esters).
7.
8.
A graphite electrode modified with cobalt hexacyanoferrate by mechanical immobilization was used for amperometric determination of hydrazine. The modified electrode exhibits good catalytic activity for the oxidation of hydrazine at a reduced overpotential with remarkable sensitivity. The modified electrode showed a linear response for hydrazine in the concentration range of 2.0 × 10–5 to 2.8 × 10–4 M. The detection limit was 9.8 × 10–6 M (S/N = 3). The proposed modified electrode was simple, sensitive, rapid, stable and promising. 相似文献
9.
R. Srinivasan 《Pramana》2006,66(1):3-30
Rotating dilute Bose-Einstein condensates (BEC) of alkali atoms offer a testing ground for theories of vortices in weakly
interacting superfluids. In a rotating super-fluid, quantised vortices, with a vorticity h/m, form above a critical velocity.
Such vortices have been generated in BEC of alkali atoms by different techniques such as (a) wave function engineering of
a two-component BEC, (b) decay of solitons, (c) rotation of a thermal cloud before cooling it below the condensation temperature,
(d) stirring with an ‘optical’ spoon, (e) rotating a deformation in the anisotropic trap in which the condensate is trapped
and (f) by creating Berry phase by adiabatically reversing the axial magnetic field. Since the core of a vortex is a fraction
of a micrometer in diameter, it cannot be directly imaged optically. The condensate with vortices is allowed to ballistically
expand till the size increases by one order before the vortices are imaged. Surface wave spectroscopy and the change in aspect
ratio of a rotating cloud are the other techniques used. Studies have been made on the creation and dynamics of single vortex
and on systems with more than a hundred vortices. Results have been obtained on vortex nucleation, stability of vortex structures,
nature of the vortex lattice and defects in such a lattice. Important results are: (a) evidence exists that vortex nucleation
takes place by a surface mode instability; but this is not the only mechanism; (b) the vortex lattice is perfectly triangular
right up to the edge; (c) in the initial stages of rotation of the cloud a tangled web of vortices is seen; it takes a few
hundred milliseconds before the vortices arrange themselves in a lattice; this time appears to be independent of temperature;
(d) the decay of vortices appears to arise from the transfer of energy to the rotating thermal component and is dependent
on temperature; (e) defects in the lattices such as dislocations and grain boundaries are seen; (f) transverse oscillations
(Tkachenko modes) of the vortex lattice have been observed; and (g) giant vortices have been produced. These will be discussed. 相似文献
10.
Bikshandarkoil R. Srinivasan 《Journal of Chemical Sciences》2004,116(5):251-259
The complexes [MoX4]2− (M = Mo; X = O or S) exist as the monomeric tetrahedral species in aqueous alkaline solutions. Acidification of tetraoxomolybdate
results in the condensation of the tetrahedral units via a series of polyoxomolybdates leading to the ultimate formation of
the trioxide MoO3. Heptamolybdate [Mo7O24]6− is the first major polyanion of the acidification reaction. In contrast, acidification of tetrathiomolybdates leads to the
formation of amorphous molybdenum trisulphide via a dinuclear Mo(V) complex. The formation of the dinuclear Mo(V) complex
precludes the formation of any higher nuclearity Mo(VI)-S complexes in aqueous solution. Thus it is shown that the all-sulphur
analogue of heptamolybdate [M07S24]6− does not exist in alkaline medium and also cannot be isolated from aqueous acidic medium 相似文献