نتایج جستجو برای: dykes decreasing the resistivity
تعداد نتایج: 16058345 فیلتر نتایج به سال:
The theory of large scale dynamos is reviewed with particular emphasis on the magnetic helicity constraint in the presence of closed and open boundaries. In the presence of closed or periodic boundaries, helical dynamos respond to the helicity constraint by developing small scale separation in the kinematic regime, and by showing long time scales in the nonlinear regime where the scale separati...
The paramagnetic phase of the two-channel Anderson lattice model in the Kondo limit is investigated in infinite spatial dimensions using the noncrossing approximation. The resistivity exhibits a Kondo upturn with decreasing T , followed by a slow decrease to a finite value at T 0. The decrease reflects lattice coherence effects in concert with particle-hole symmetry breaking. The magnetoresis...
Bi1.8Pb0.4Sr2-xBaxCa2.2Cu3Oy (x-0, 0.1, 0.2, 0.3) samples were prepared by a conventional solid state reaction method. The effect of Ba substitution at Sr site in Bi-2223 high-TC superconductors have been investigated by the XRD, SEM, dc electrical resistivity and ac susceptibility. XRD and SEM analysis indicated Ba substitution decreased temperature of 2223 phase formation. The highest 2223 ph...
The study area is located in NW of Iran, East-Azarbaidjan Province in north Varzeghan. Plagioclase, amphibole and biotite are the major minerals and sphene, apatite, and quartz are accessory minerals. The texture of these dykes are porphyrytic with fine to medium matrix. Mineral chemistry analysis revealed that the composition of Plagioclase varies from andesine to oligoclase and the biotite va...
In this paper, we determine the surface and volume electrical resistivity of the 50 μm thick cellular polypropylen (VHD50), for the temperature range 393-453 K. For this we use a contemporary methodology, which consist of a voltage measurement across the sample, with a known current flowing through it. This methodology includes a three-electrode system, which allows us to estimate the resistivi...
Colossal electroresistance (CER) has been observed in the ferromagnetic insulating (FMI) state of a manganite. Notably, the CER in the FMI state occurs in the absence of magnetoresistance (MR). Measurements of electroresistance (ER) and current induced resistivity switching have been performed in the ferromagnetic insulating state of a single crystal manganite of composition Nd0.7Pb0.3MnO3 (NPM...
The metamorphic sole rocks at the base of mantle peridotites from the Mersin ophiolite consist of amphibolites and metasedimentary lithologies. Mineral parageneses in the metamorphic sole rocks exhibit amphibolite and greenschist facies assemblages. Geothermobarometric studies based on mineral assemblages and chemical compositions of minerals indicate that average metamorphic temperature during...
In this investigation, the effect of Lanthanum vacancy on the structural, electrical and magnetic properties of La1-xMnO3+δ manganite (x=0, 0.05) was studied. Decreasing La3+ amount in samples led to creation of some Mn4+ cations. By increasing the Mn4+content in atomic structure of samples, double exchange interaction was strengthened. Results of Ac magnetic susceptibility measurements indica...
Polycrystalline samples of Y1-2xCaxThxBa2Cu3O7-δ (with 0.00 ≤x ≤ 0.075) and NdBa2-xLaxCu3O7-δ (with 0.0≤x≤ 0.30) were prepared by the standard solid state method. The transport and superconducting properties have been studied by the resistivity measurements as a function of temperature and doping concentration. Data of resistivity as a function of temperature was analyzed in terms of the bipola...
geophysical techniques remain the only ways to remotely and non-destructively sense the earth’s near subsurface and as such have the most promising prospect for rapid and accurate detection of underground tunnels. today, electrical resistivity and seismic refraction geophysical methods have been greatly developed to identify structures and underground cavities. in this study, the ability of the...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید