排序方式: 共有58条查询结果,搜索用时 15 毫秒
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MP Janawadkar R Baskaran R Nagendran K Gireesan N Harishkumar Rita Saha L S Vaidhyanathan J Jayapandian Y Hariharan TS Radhakrishnan 《Pramana》2002,58(5-6):1159-1164
A program has been developed and initiated at the Indira Gandhi Centre for Atomic Research (IGCAR) for the utilization of
SQUID sensors in various application areas. DC SQUID sensors based on Nb-AlO
x
-Nb Josephson junctions have been designed and developed inhouse along with associated flux-locked loop (FLL) electronics.
A compact low field SQUID magnetometer insertible in a liquid helium storage dewar has also been developed inhouse and is
in use. Efforts to build a high field SQUID magnetometer, SQUID-DAC system, are in progress. A planar gradiometric DC SQUID
sensor for non-destructive evaluation (NDE) application to be used in relatively unshielded environment has been designed
and developed. An easily portable NDE cryostat with a small lift-off distance, to be used in external locations has been designed
and tested. The magnetic field produced by a given two-dimensional current density distribution is inverted using the Fourier
transform technique. 相似文献
33.
MP Blencowe 《Contemporary Physics》2013,54(4):249-264
Nanoelectromechanical systems (NEMS) are nano-to-micrometer scale mechanical resonators coupled to electronic devices of similar dimensions. NEMS show promise for fast, ultrasensitive force microscopy and for deepening our understanding of how classical dynamics arises by approximation to quantum dynamics. This article begins with a survey of NEMS and then describes certain aspects of their classical dynamics. In particular, we show that for weak coupling the action of the electronic device on the mechanical resonator can be effectively that of a thermal bath, this despite the device being a driven, far-from-equilibrium system. 相似文献
34.
Reem Jaafar S. McHugh Yoko Suzuki M.P. Sarachik Y. Myasoedov E. Zeldov H. Shtrikman R. Bagai G. Christou 《Journal of magnetism and magnetic materials》2008
Using time-resolved measurements of local magnetization in the molecular magnet Mn12-ac, we report studies of magnetic avalanches (fast magnetization reversals) with non-planar propagating fronts, where the curved nature of the magnetic fronts is reflected in the time-of-arrival at micro-Hall sensors placed at the surface of the sample. Assuming that the avalanche interface is a spherical bubble that grows with a radius proportional to time, we are able to locate the approximate ignition point of each avalanche in a two-dimensional cross-section of the crystal. We find that although in most samples the avalanches ignite at the long ends, as found in earlier studies, there are crystals in which ignition points are distributed throughout an entire weak region near the center, with a few avalanches still originating at the ends. 相似文献
35.
Vitkalov SA Zheng H Mertes KM Sarachik MP Klapwijk TM 《Physical review letters》2000,84(10):2164-2167
We show that the smectic layer orientation in side-chain liquid-crystalline polymers depends on the molecular weight and the shear rate. Parallel orientation is obtained with the low molecular weight polymer and reveals a shear induced decrease of the smectic layer thickness. In contrast with usual liquid crystals, the shear torque acts at the mesogen scale through an efficient coupling between the polymer main chain and the mesogens resulting in a smectic- A-smectic- C transition. 相似文献
36.
Using a streak camera we have measured the three Stokes polarization parameters during a polarization switch of a vertical-cavity semiconductor laser. The switch occurs along a corkscrew path on the Poincare sphere and takes on average a few nanoseconds; this value agrees with a theoretical treatment based upon the Fokker-Planck equation. 相似文献
37.
M. P. Sarachik D. Simonian K. M. Mertes S. V. Kravchenko T. M. Klapwijk 《Physica B: Condensed Matter》2000,280(1-4):301-302
Hall coefficient measurements are reported for the two-dimensional electron system in silicon MOSFETs for densities throughout the metallic phase and very near the transition to insulating behavior. 相似文献
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Thermoelectric power data between 4.2 and 300°K are presented for Ir containing 0.5 and 1 at.% Fe and for pure Ir. Peaks similar to those found in Pd(Ni) and Rh(Fe) occur in Ir(Fe) at the spin fluctuation temperature Tsf = 28°K, independent of solute concentration. Similarities and differences among the three alloy systems are discussed. 相似文献
40.
Electrical resistivity measurements between 2 and 700°K on NiRh alloys, which have giant magnetic polarization clouds, reveal a magnetic scattering behavior that is strikingly different from that found in giant-moment NiCu alloys. 相似文献