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1.
M. Amar D. Andreucci R. Gianni C. Timofte 《Journal of Mathematical Analysis and Applications》2021,493(2):124533
We prove a well-posedness result for two pseudo-parabolic problems, which can be seen as two models for the same electrical conduction phenomenon in heterogeneous media, neglecting the magnetic field. One of the problems is the concentration limit of the other one, when the thickness of the dielectric inclusions goes to zero. The concentrated problem involves a transmission condition through interfaces, which is mediated by a suitable Laplace-Beltrami type equation. 相似文献
2.
Clemens G. Raab Georg Regensburger Jamal Hossein Poor 《Journal of Pure and Applied Algebra》2021,225(5):106564
A formal computation proving a new operator identity from known ones is, in principle, restricted by domains and codomains of linear operators involved, since not any two operators can be added or composed. Algebraically, identities can be modelled by noncommutative polynomials and such a formal computation proves that the polynomial corresponding to the new identity lies in the ideal generated by the polynomials corresponding to the known identities. In order to prove an operator identity, however, just proving membership of the polynomial in the ideal is not enough, since the ring of noncommutative polynomials ignores domains and codomains. We show that it suffices to additionally verify compatibility of this polynomial and of the generators of the ideal with the labelled quiver that encodes which polynomials can be realized as linear operators. Then, for every consistent representation of such a quiver in a linear category, there exists a computation in the category that proves the corresponding instance of the identity. Moreover, by assigning the same label to several edges of the quiver, the algebraic framework developed allows to model different versions of an operator by the same indeterminate in the noncommutative polynomials. 相似文献
3.
4.
Marcus Carlsson 《Expositiones Mathematicae》2021,39(1):149-157
von Neumann’s inequality in matrix theory refers to the fact that the Frobenius scalar product of two matrices is less than or equal to the scalar product of the respective singular values. Moreover, equality can only happen if the two matrices share a joint set of singular vectors, and this latter part is hard to find in the literature. We extend these facts to the separable Hilbert space setting, and provide a self-contained proof of the “latter part”. 相似文献
5.
6.
Functional Carbazole Liquid‐Crystal Block Codendrimers with Optical and Electronic Properties
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Ismael Gracia Beatriz Feringán Prof. José Luis Serrano Dr. Roberto Termine Dr. Attilio Golemme Dr. Ana Omenat Prof. Joaquín Barberá 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(3):1359-1369
The synthesis and characterisation of a family of block codendrimers consisting of highly versatile mesogenic and carbazole‐containing 2,2‐bis(hydroxymethyl)propionic acid (bis‐MPA) dendrons are reported. The liquid‐crystal behaviour was investigated by means of differential scanning calorimetry, polarised‐light optical microscopy and X‐ray diffraction. Depending on the chemical structure of the constituent dendrons, the codendrimers show lamellar or columnar mesophases. On the basis of the experimental results, models both at the molecular level and in the mesophase are proposed. The physical properties of the block codendrimers derived from the presence of the carbazole moiety in their structure were investigated: photoluminescence in solution and in the mesophase, electrochemical behaviour and hole transport. Electrodeposition of carbazole dendrons afforded a globular supramolecular conformation in which the mesogenic molecular side plays a key role. 相似文献
7.
Sha Xia Dan Wang Nian-Ke Chen Dong Han Xian-Bin Li Hong-Bo Sun 《Annalen der Physik》2020,532(3):1900318
Defects play a central role in controlling the electronic properties of two-dimensional (2D) materials and realizing the industrialization of 2D electronics. However, the evaluation of charged defects in 2D materials within first-principles calculation is very challenging and has triggered a recent development of the WLZ (Wang, Li, Zhang) extrapolation method. This method lays the foundation of the theoretical evaluation of energies of charged defects in 2D materials within the first-principles framework. Herein, the vital role of defects for advancing 2D electronics is discussed, followed by an introduction of the fundamentals of the WLZ extrapolation method. The ionization energies (IEs) obtained by this method for defects in various 2D semiconductors are then reviewed and summarized. Finally, the unique defect physics in 2D dimensions including the dielectric environment effects, defect ionization process, and carrier transport mechanism captured with the WLZ extrapolation method are presented. As an efficient and reasonable evaluation of charged defects in 2D materials for nanoelectronics and other emerging applications, this work can be of benefit to the community. 相似文献
8.
9.
《Physics letters. A》2019,383(17):2090-2092
In this paper, we have used Monte Carlo (MC) method to simulate and study the temperature and doping effects on the electric conductivity of fullerene (C60). The results show that the band gap has reduced by the doping and the charge carrier transport is facilitated from valence band to conduction band by the temperature where is touched a 300 K. In this case, the conductivity reached a value of . The electric conductivity of C60 can increase by the triphenylmethane dye crystal violet (CV) alkali metal to reach at 303 K. Our results of MC simulation have a good agreement with those extracted from literature [10], [33]. 相似文献
10.
Inner derivations and norm equality 总被引:3,自引:0,他引:3
Mohamed Barraa Mohamed Boumazgour 《Proceedings of the American Mathematical Society》2002,130(2):471-476
We characterize when the norm of the sum of two bounded operators on a Hilbert space is equal to the sum of their norms.