排序方式: 共有108条查询结果,搜索用时 15 毫秒
31.
The response of giant magnetoresistance (GMR) devices depends critically on the film microstructure, with parameters such
as layer thickness and interfacial abruptness being crucial. This paper presents results obtained using high resolution electron
microscopy (HREM), chemical mapping and atom probe microanalysis. Local variations in the magnetic properties are induced
by the microstructure and also when the films are patterned to form small elements. These lead to changes in the magnetization
reversal mechanism. Some results of the studies of the magnetization reversal carried out using in situ in Lorentz transmission electron microscopy (LTEM) magnetizing experiments are also included. 相似文献
32.
A very rapid and efficient method has been developed for the synthesis of vicinal bromohydrins and alkoxybromides directly from an olefin without any catalyst. The reaction was performed in CH3CN-water (4:1) or alcohol using N,N-dibromo-p-toluenesulfonamide (TsNBr2) as the brominating agent. Excellent yields and regio- and stereoselectivities have been obtained. Bromohydrins are formed instantaneously, whereas formation of alkoxybromides takes 30-60 min. 相似文献
33.
We have studied the peak effect (PE) phenomenon in single crystals of weakly pinned superconductors CeRu2 and 2H-NbS2. 2H-NbS2 is iso-structural and iso-electronic to 2H-NbSe2, whose similarity with CeRu2 as regards the PE representing the order-to-disorder transformation of the flux line lattice was claimed some time ago. We
report on the step change in equilibrium magnetization across the peak effect in CeRu2. We also present the vortex phase diagram of 2H-NbS2 obtained from the magnetization data, and compare the PE phenomenon in 2H-NbS2 and 2H-NbSe2. 相似文献
34.
Effect of Discharge Voltage on an Ion Sheath Formed at a Grid in a Multi-Dipole Discharge Plasma 下载免费PDF全文
M. K. Mishra A. Phukan 《中国物理快报》2008,25(3):1011-1014
It is experimentally demonstrated that a relatively strong ion-rich sheath formed at a fixed negative bias of the grid can be changed to a rather weak ion sheath (sheath potential weakly retards electrons) only by increasing the discharge voltage in the system. At sufficiently high negative grid bias, an increase of discharge voltage enhances the ion collection current at the grid. An explanation is put forward in support of this experimental observation. A slight density enhancement with a fall in plasma electron temperature is also observed with the increasing negative grid bias. 相似文献
35.
Atul Srivastava Atanu Phukan P. K. Panigrahi K. Muralidhar 《Optics and Lasers in Engineering》2004,42(4):73
The present study is concerned with the quantitative imaging of buoyancy-driven convection in a fluid medium that is confined in a horizontal differentially heated rectangular cavity. The horizontal surfaces of the cavity provide a temperature difference, for initiating convection in the fluid. The vertical side walls are thermally insulated. Three imaging techniques, namely laser interferometry, schlieren, and shadowgraph have been utilized. Experiments have been conducted in a cavity of length 447 mm and 32 mm vertical height. The cavity is square in cross-section, and the imaging direction is parallel to its longer side. Convection in air and water have been investigated. Temperature differences in the range of 5–50 K for air and 3–10 K for water have been employed in the experiments. Quantities of interest are the temperature profiles in unsteadiness in the thermal field. At lower temperature differences across the fluid region, temperatures as recorded by interferometry and schlieren are in good agreement with each other. Further, they match the numerical predictions, as well as correlations available in the literature. Imaging based on shadowgraph is not as satisfactory at lower temperature differences. At larger cavity temperature differences, the shadowgraph images become clear enough for quantitative analysis, but the flow becomes time-dependent. The three techniques reveal similar trends in terms of the spatial distribution of temperature gradients and the time scales of unsteadiness. The schlieren and shadowgraph are more suitable for high gradients and interferometry is suitable for low gradients and all these three techniques are not flow visualization tools alone but are appropriate for quantitative imaging of thermal field. 相似文献
36.
Noncollinear difference frequency mixing of dye laser and Nd:YAG second harmonic (fundamental) radiation from a commercial
laser system is employed for the generation of 2.7–5.3 μm (1.6–1.7 μm) radiations in a flux-grown KTiOAsO1 crystal. The generated radiation is used to scan the methane absorption in the fundamental (v
3) and its first overtone (2v
3) band at pressure 90 torr in a laboratory made single pass gas cell of length 33 cm. 相似文献
37.
§ 1.Introduction WearegivenkindependentWishartdensitiesofthe (p +q)× (p +q)randomsymmetricpositivedefinitematricesG1,… ,Gktobeg(Gi) =Kexp -12 trR- 1i Gi Gi12 (ni- q-p- 1) ,(1 )wherei=1 ,… ,k,andRidenotesthepopulationcorrelationmatrixofthei thpopulationandKasagenericletterdenote… 相似文献
38.
M. K. Mishra A. Phukan M. Chakraborty K. S. Goswami 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(2):303-306
This paper reports about the observed energy growth of
both high and low energetic electron species in the target plasma region
with the increase in plasma potential in the source region of a double
plasma device. This situation can be correlated to the injection of an ion
beam from source to target plasma region. Plasma is solely produced in the
source region and a low-density diffuse plasma is generated in the target
region by local ionization between the neutral gas and the high energetic
electrons coming from the source region. The growth of electron energy is
accompanied by a decrease in diffuse plasma density. It is observed that
although energy of high energetic group increases with the injected beam
energy, the diffuse plasma density falls due to their decreasing population. 相似文献
39.
The behaviour ofS-matrix for potentials generating bound states in continuum in the neighbourhood of the positive bound state energies is studied.
It is shown that unlike the case of usual negative energy bound states, theS-matrix does not have a pole at the positive bound state energy but becomes unity at the energy corresponding to bound states
in continuum. Calculations ofS-waveS-matrix for a local potential constructed by Stillinger and Herrick and a separable nonlocal potential constructed by the
present authors verify these results. Our results indicate that the bound states embedded in continuum constructedvia the von Neumann and Wigner procedure cannot be interpreted as resonances with zero width. 相似文献
40.
Emre GÜZEL Fatih S
NMEZ Sultan ERKAN Kübra IKRIKI Adem ERGÜN Nahit GENER Oktay ARSLAN Makbule B KOAK 《Turkish Journal of Chemistry》2020,44(6):1565
The investigation of carbonic anhydrase and paraoxonase enzyme inhibition properties of water-soluble zinc and gallium phthalocyanine complexes ( 1 and 2 ) are reported for the first time. The binding of p-sulfonylphenoxy moieties to the phthalocyanine structure favors excellent solubilities in water, as well as providing an inhibition effect on carbonic anhydrase (CA) I and II isoenzymes and paraoxonase (PON1) enzyme. According to biological activity results, both complexes inhibited hCA I, hCA II, and PON1. Whereas 1 and 2 showed moderate hCA I and hCA II (off-target cytosolic isoforms) inhibitory activity (Ki values of 26.09 µM and 43.11 µM for hCA I and 30.95 µM and 33.19 µM for hCA II, respectively), they exhibited strong PON1 (associated with high-density lipoprotein [HDL]) inhibitory activity (Ki values of 0.37 µM and 0.27 µM, respectively). The inhibition kinetics were analyzed by Lineweaver–Burk double reciprocal plots. It revealed that 1 and 2 were noncompetitive inhibitors against PON1, hCA I, and hCA II. These complexes can be more advantageous than other synthetic CA and PON inhibitors due to their water solubility. Docking studies were carried out to examine the interactions between hCA I, hCA II, and PON1 inhibitors and metal complexes at a molecular level and to predict binding energies. 相似文献