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31.
We estimate the rate of decay of the difference between a solution and its limiting equilibrium for the following abstract second order problem
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32.
La0.67Sr0.33FexMn1-xO3, with x = 0.0, 0.1, 0.2 and 1 have been elaborated by mechanical system. X-ray diffraction, Scanning electron microscopy, Magnetic measurements and M?ssbauer spectroscopy for the systems have been investigated. Rietveld analysis of the X-ray powder diffraction show that the samples crystallise in the orthorhombic perovskite system with Pnma space group. The average particle size of about 60 nanometre was obtained from scanning electron microscopy and X-ray diffraction. The investigated samples exhibit a ferromagnetic to paramagnetic transition with increasing temperature. The presence of manganese in the structure leads to an increase of the Curie temperature as well as to spontaneous magnetization. The magnetization versus applied magnetic field shows a small coercive field and an unsaturated magnetization which indicates that the nanoparticles of all samples are superparamagnetic at around room temperature. Room temperature M?ssbauer spectra show that the samples with x = 0.1 and x = 1.0 contain minority α-Fe2O3 and other spinel ferrite species. Also, they indicate that Fe3?+? ions are present in slightly distorted octahedral sites in the samples with x = 0.1 and 0.2, while mixed Fe valency was observed for the sample with x = 1.0.  相似文献   
33.
In this paper, a gate-all-around junctionless tunnel field effect transistor (JLTFET) based on heterostructure of compound and group III–V semiconductors is introduced and simulated. In order to blend the high tunneling efficiency of narrow band gap material JLTFETs and the high electron mobility of III–V JLTFETs, a type I heterostructure junctionless TFET adopting Ge–Al x Ga1?x As–Ge system has been optimized by numerical simulation in terms of aluminum (Al) composition. To improve device performance, we considered a nanowire structure, and it was illustrated that high-performance logic technology can be achieved by the proposed device. The optimal Al composition founded to be around 20 % (x = 0.2). The numerical simulation results demonstrate that the proposed device has low leakage current I OFF of ~1.9 × 10?17, I ON of 4 µA/µm, I ON/I OFF current ratio of 1.7 × 1011 and subthreshold swing SS of 12.6 mV/decade at the 40 nm gate length and temperature of 300 K.  相似文献   
34.
35.
The authors consider the existence of singular limit solution for a family of nonlinear elliptic problems with exponentially dominated nonlinearity and Navier boundary condition.  相似文献   
36.
This paper deals with the homogenization of a class of nonlinear elliptic problems with quadratic growth in a periodically perforated domain. The authors prescribe a Dirichlet condition on the exterior boundary and a nonhomogeneous nonlinear Robin condition on the boundary of the holes. The main difficulty, when passing to the limit, is that the solution of the problems converges neither strongly in L~2(Ω) nor almost everywhere in Ω. A new convergence result involving nonlinear functions provides suitable weak convergence results which permit passing to the limit without using any extension operator.Consequently, using a corrector result proved in [Chourabi, I. and Donato, P., Homogenization and correctors of a class of elliptic problems in perforated domains, Asymptotic Analysis, 92(1), 2015, 1–43, DOI: 10.3233/ASY-151288], the authors describe the limit problem, presenting a limit nonlinearity which is different for the two cases, that of a Neumann datum with a nonzero average and with a zero average.  相似文献   
37.
A mixed-metal Lindqvist-type heteropolyanion of organic cation; (C8H14N2)2[V2W4O19]?2H2O (m-XDAV2W4) has been synthesized hydrothermally and characterized by means ICP and elemental analysis, X-ray diffraction, IR, UV–Vis, luminescence and biological analyses. The X-ray structural analysis supported by a detailed Hirshfeld surface analysis and fingerprint plots has been elucidated the different inter-contacts in the crystal structure mainly associated with O…H/H…O close contacts between [V2W4O19]4? (V2W4) clusters, water molecules and m-xylylenediammonium entities so stabilizing the 3D-supramolecular structure. The optical survey reveals an important HOMO–LUMO band gap indicating stability and blue luminescent behavior of reported material. Moreover, the biological trials indicated that this compound displays promising antibacterial and antifungal activities.  相似文献   
38.
Antioxidant properties and angiotensin-converting enzyme (ACE) inhibitory activities of protein hydrolysates from goby (Zosterisessor ophiocephalus) muscle, with different degrees of hydrolysis (DH) from 5 to 25 %, prepared by treatment with crude proteases extract from smooth hound intestines, were investigated. Goby protein hydrolysates (GPHs) are rich in Gly and Thr, which accounted for 14.1–15 % and 11.6–13.2 % of the total amino acids, respectively. The antioxidant activities of GPHs were investigated by using several in vitro assay systems. All GPHs exhibited significant metal chelating activity and DPPH free radical-scavenging activity, and inhibited linoleic acid peroxidation. For the ACE-inhibitory activity, as the DH increased, the activity of GPHs increased. The obtained results revealed that antioxidant and ACE-inhibitory activities of GPHs were influenced by the degree of hydrolysis. A medium degree of enzymatic hydrolysis was appropriate to obtain GPHs with good antioxidant activity, while small peptides were essential to obtain high ACE inhibitory activity.  相似文献   
39.
In this work we propose a technetium-99m-labeled derivative from Ethionamide (ETH), further referred to as 99mTc-ECF for tuberculosis diagnosis. The biological features of this radioactive agent have been studied. The 2-ethylpyridine-4-carbothioamide-ferrocène (ECF) was chemically synthesized and then labeled with technetium-99m. It has been confirmed through this work that 99mTc-ECF is obtained with high radiolabelling yield (>90 %). Radiochemical analysis of 99mTc-ECF revealed that the molecule was efficiently labeled with a little free remaining pertechnetate. Only 1–2 % of the tracer was leached out from the complex at 24 h when incubated in serum at 37 °C which confirmed its high stability. The sensitivity test of ECF showed that the group of grafted ferrocenyl does not seem to have largely altered the active site of the molecule. In-vitro investigations were conducted using BCG (Bacille Calmette-Guérin) as analogue of Mycobacterium Tuberculosis and Listeria Monocytogenes as negative control. It was proved that for BCG, ECF has kept the bacteriostatic properties of the parent compound (ETH). In physiological conditions, the measured up-take of the tracer with live bacteria was about 24.1 and 7.1 % for BCG and Listeria Monocytogenese, respectively. The comparison of the 99mTc-ECF accumulation at sites of BCG infected animals, which is expressed as target-to-non-target ratio (found to be equal to 2.15) with other radiotracers was discussed. This allowed us to consider that 99mTc-ECF could be a reasonable radiotracer for mycobacterial infections. Obtained results were good and encourage to undergo a similar labeling for the Mycobacterium tuberculosis as perspective of this work.  相似文献   
40.
Journal of Thermal Analysis and Calorimetry - Thermal analysis confirmed the presence of the phase transition at T?=?320 K in the Cs2SeO4·H6TeO6 (CsSeTe) material. The...  相似文献   
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