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51.
Samir EL Mourchid 《Semigroup Forum》2006,73(2):313-316
Let A be a generator of a C0-semigroup T(·) on a separable Banach space. Under suitable conditions on the imaginary point spectrum of A,
we show that T(·) is hypercyclic. 相似文献
52.
Ayman El Tahan Gerhard Jakob Hermann Adrian Lucica Miu 《Physica C: Superconductivity and its Applications》2010,470(1):1-7
YBa2Cu3O7/PrBa2Cu3O7 (YBCO/PBCO) superlattices with a different ratio of the superconducting and insulating layer thicknesses were prepared by high pressure dc sputtering. The vortex-creep activation energy U0 was determined by analyzing the in-plane resistive transition of 200 μm wide bridges with the external magnetic field B oriented along the c axis. It was found that U0 is proportional to the thickness of the YBCO layers, and does only weakly depend on the PBCO layer thickness, when the latter exceeds two unit cells. We observed a change in the variation of U0 with the current I in the specimen: U0 exhibits a plateau in the low-I region, then decreases significantly with increasing I. This behaviour is explained in terms of a crossover plastic vortex creep – elastic (collective) creep induced by the transport current. 相似文献
53.
We propose an approach to optical microscopy that enables full control over the three-dimensional polarization vector at the focal spot of a high-numerical-aperture lens. The input field to the lens is linearly polarized and no polarization optics are needed. This technique utilizes the azimuthal spatial degree of freedom of the input field. We find that only a small set of low-order azimuthal spatial harmonics contributes to the focused field on axis, and a simple transformation exists between the linear vector space of these harmonics and the three-dimensional polarization-vector space. Controlling the relative complex weights of these azimuthal harmonics produces any desired three-dimensional state of polarization. 相似文献
54.
The DC electrical resistivity (p) was studied for Co substituted SbNi ferrites as a function of temperature and composition. The experimental results showed that DC resistivity, Curie temperature and activation energies for electrical conduction increase as Co-ion substitution decreases. The DC electrical conductivity increases as temperature increases. The real part of dielectric constant (e') was found to be inversely proportional to the root mean square value of the electrical resistivity. 相似文献
55.
Ayman Badawi 《代数通讯》2013,41(5):2343-2358
A prime ideal P of a ring A is said to be a strongly prime ideal if aP and bA are comparable for all a,b ε A. We shall say that a ring A is a pseudo-valuation ring (PVR) if each prime ideal of A is a strongly prime ideal. We show that if A is a PVR with maximal ideal M, then every overring of A is a PVR if and only if M is a maximal ideal of every overring of M that does not contain the reciprocal’of any element of M.We show that if R is an atomic domain and a PVD, then dim(R) ≤ 1. We show that if R is a PVD and a prime ideal of R is finitely generated, then every overring of R is a PVD. We give a characterization of an atomic PVD in terms of the concept of half-factorial domain. 相似文献
56.
Farid Rachidi Mutale-joan Chanda Redouane Benhima Mernissi Najib EL Abderahime Aasfar Laila Sbabou Arroussi Hicham EL 《Applied biochemistry and biotechnology》2019,188(1):225-240
Applied Biochemistry and Biotechnology - Microalgae are photosynthetic microorganisms that produce several bioactive molecules that have received considerable attention in scientific and industrial... 相似文献
57.
Al-Noaimi Mousa Awwadi Firas F. Hammoudeh Ayman Tanash Maha 《Transition Metal Chemistry》2019,44(4):355-367
Transition Metal Chemistry - Eight ruthenium complexes having thioalkyl-azoimine (SNN) ligands of two general types have been synthesized: (a) [Ru(L)(bipy)Cl](PF6) where {bipy = bipyridine,... 相似文献
58.
Foudah Ahmed I. Alam Prawez Al Furaih Abdulaziz I. Salkini Mohammad Ayman A. Abdel-Kader Maged S. 《平面色谱法杂志一现代薄层色谱法》2019,32(2):89-93
JPC – Journal of Planar Chromatography – Modern TLC - Fenugreek is one of the oldest medicinal plants known by mankind. The aim of this study is to evaluate the effect of environmental... 相似文献
59.
Siddiqui Samia Nafady Ayman El-Sagher Hussein M. Al-Saeedi Sameerah I. Alsalme Ali M. Sirajuddin Talpur Farah N. Sherazi Syed Tufail H. Kalhoro Muhammad S. Shah Muhammad R. Shaikh Tayyaba Arain Munazza Bhargava Suresh K. 《Journal of Solid State Electrochemistry》2019,23(7):2073-2083
Journal of Solid State Electrochemistry - Bimetallic nanoparticles (BMNPs) have received considerable attention due to their distinctive properties when compared to the corresponding monometallic... 相似文献
60.
Liu D Chu XQ Lagi M Zhang Y Fratini E Baglioni P Alatas A Said A Alp E Chen SH 《Physical review letters》2008,101(13):135501
Molecular dynamics simulations and neutron scattering experiments have shown that many hydrated globular proteins exhibit a universal dynamic transition at TD = 220 K, below which the biological activity of a protein sharply diminishes. We studied the phononlike low-energy excitations of two structurally very different proteins, lysozyme and bovine serum albumin, using inelastic x-ray scattering above and below TD. We found that the excitation energies of the high-Q phonons show a marked softening above TD. This suggests that the large amplitude motions of wavelengths corresponding to this specific Q range are intimately correlated with the increase of biological activities of the proteins. 相似文献