共查询到20条相似文献,搜索用时 0 毫秒
1.
Steven T. Dougherty Hongwei Liu Long Yu 《Applicable Algebra in Engineering, Communication and Computing》2016,27(2):123-138
We study one weight \(\mathbb {Z}_2\mathbb {Z}_4\) additive codes. It is shown that the image of an equidistant \(\mathbb {Z}_2\mathbb {Z}_4\) code is a binary equidistant code and that the image of a one weight \(\mathbb {Z}_2\mathbb {Z}_4\) additive code, with nontrivial binary part, is a linear binary one weight code. The structure and possible weights for all one weight \(\mathbb {Z}_2\mathbb {Z}_4\) additive codes are described. Additionally, a lower bound for the minimum distance of dual codes of one weight additive codes is obtained. 相似文献
2.
Omran Ahmadi 《Applicable Algebra in Engineering, Communication and Computing》2007,18(4):391-396
In this paper we study the trace spectra of polynomial bases for over . Shparlinski showed that there exists a polynomial basis having O(log n) elements of trace one. Here we show that for every t ≤ n, there exists a polynomial basis having t + O(log n) elements of trace one. We also study consequences of our results to the existence of irreducible polynomials of certain
weights. 相似文献
3.
Yonglin Cao Yuan Cao Fang-Wei Fu 《Applicable Algebra in Engineering, Communication and Computing》2016,27(4):259-277
Let \({\mathbb {F}}_{2^m}\) be a finite field of characteristic 2 and \(R={\mathbb {F}}_{2^m}[u]/\langle u^k\rangle ={\mathbb {F}}_{2^m} +u{\mathbb {F}}_{2^m}+\ldots +u^{k-1}{\mathbb {F}}_{2^m}\) (\(u^k=0\)) where \(k\in {\mathbb {Z}}^{+}\) satisfies \(k\ge 2\). For any odd positive integer n, it is known that cyclic codes over R of length 2n are identified with ideals of the ring \(R[x]/\langle x^{2n}-1\rangle \). In this paper, an explicit representation for each cyclic code over R of length 2n is provided and a formula to count the number of codewords in each code is given. Then a formula to calculate the number of cyclic codes over R of length 2n is obtained. Moreover, the dual code of each cyclic code and self-dual cyclic codes over R of length 2n are investigated. 相似文献
4.
Maheshanand Bhaintwal Siri Krishan Wasan 《Applicable Algebra in Engineering, Communication and Computing》2009,20(5-6):459-480
Quasi-cyclic (QC) codes are a remarkable generalization of cyclic codes. Many QC codes have been shown to be best for their parameters. In this paper, some structural properties of QC codes over the prime power integer residue ring ${\mathbb{Z}_q}$ are considered. An l-QC code of length lm over ${\mathbb{Z}_q}$ is viewed both as in the conventional row circulant form and also as a ${\frac{\mathbb{Z}_q[x]}{\langle x^m-1 \rangle}}$ -submodule of ${\frac{GR(q,l)[x]}{\langle x^m-1 \rangle}}$ , where GR(q, l) is the Galois extension ring of degree l over ${\mathbb{Z}_q}$ . A necessary and sufficient condition for cyclic codes over Galois rings to be free is obtained and a BCH type bound for them is also given. A sufficient condition for 1-generator QC codes to be ${\mathbb{Z}_q}$ -free is given and a formula to evaluate their ranks is derived. Some distance bounds for 1-generator QC codes are also discussed. The duals of QC codes over ${\mathbb{Z}_q}$ are also briefly discussed. 相似文献
5.
Magdalena Gromada Mojtaba Biglar Tomasz Trzepieciński Feliks Stachowicz 《Bulletin of Materials Science》2017,40(4):759-771
In this study, we present the results of the manufacturing of \(\hbox {BaTiO}_{3}\) powder, which is meant for use in stacked-disk multilayer actuator production. The solid-state technique was used for powder preparation. The properties of barium titanate material, at each stage of its fabrication (powder, granulate, sintered material), influencing on its application for the stacked-disk multilayer actuator were determined. Particularly, the four parameters of \(\hbox {BaTiO}_{3}\) sinter affecting on the usability properties of actuators, not found before in the literature, were estimated. Parameters characterizing the extent of material sintering, SEM microstructures and electric properties of the fabricated pellets are presented and discussed. The dilatometric curve was executed using the high temperature dilatometer to determine at which temperature barium titanate pellets and beams should be sintered to receive full dense sinters. Parameters characterizing the extent of material sintering: the apparent density, the apparent porosity and the water absorbability were estimated. Finally, the problem of metal layer deposition on barium titanate ceramics during actuator fabrication is considered. 相似文献
6.
Won-Seung Cho Kyeongsoon Park 《Journal of Materials Science: Materials in Electronics》2000,11(4):319-324
The effects of bulk porosity on the thermoelectric properties of porous n-type ${\text{Fe}}_{{\text{0}}{\text{.94}}} {\text{Co}}_{{\text{0}}{\text{.06}}} {\text{Si}}_{\text{2}} $ compounds prepared by pressureless sintering were examined. A small amount of metallic phase ?-FeSi remained after annealing at 800 °C for 100 h. As the sintering temperature increased from 1150 to 1175 °C, the phase transition to β-FeSi2 during annealing occurred more rapidly. The porous specimen, sintered at 1150 °C for 2 h with coarse powders (<45 μm) and then annealed at 800 °C for 100 h, showed the highest Seebeck coefficient of $ - 363_{\mu } {VK}^{ - {1}} $ at 400 °C and the highest power factor of ${\text{1}}{\text{.57}} \times 10^{ - 3} {\text{Wm}}^{ - 1} {\text{K}}^{ - 2} $ at 400 °C. 相似文献
7.
J. J. Li Z. W. Ouyang Y. C. Sun X. Y. Yue Z. C. Xia G. H. Rao 《Journal of Low Temperature Physics》2017,188(1-2):11-21
Nanometer scale is introduced in the well-known Haldane system \(\hbox {Y}_{2}\hbox {BaNiO}_{5}\,(S=1)\). Magnetization and pulsed-field electron spin resonance (ESR) measurements were performed. As a result, the magnetization of nanoparticles is much enhanced as compared with that of the bulk material. The Haldane gap in the bulk form tends to be suppressed as the grain size is reduced down to the nanometer scale. The chain-end \(S\hbox {-}1/2\) spins have an important contribution to the magnetism of nanoparticles. The high-field ESR data demonstrated a paramagnetic-like resonance. The frequency–field (f–H) relationship is linear and passes through the origin. The g value is about 2.16, in good agreement with the typical value of paramagnetic \(\hbox {Ni}^{2+}\). It is concluded that the nanometer scale is a new degree of freedom for controlling the ground state of quantum magnets. 相似文献
8.
Ashis Bhattacharjee Debasis Roy Madhusudan Roy 《International Journal of Thermophysics》2012,33(12):2351-2365
Thermal decomposition of oxalate-based molecular precursors, namely ${\{{\rm N}(n{-} {\rm C}_{4} {\rm H}_{9})_{4}[{\rm Zn}^{\rm II}{\rm Fe}^{\rm III}({\rm C}_{2} {\rm O}_{4})_{3}]\}_{\infty}, \{{\rm N}(n{-}{\rm C}_{4}{\rm H}_{9})_{4}[{\rm Co}^{\rm II}{\rm Fe}^{\rm III}({\rm C}_{2}{\rm O}_{4})_{3}]\}_{\infty}}$ , and ${\{{\rm N}(n{-}{\rm C}_{4} {\rm H}_{9})_{4}[{\rm Fe}^{\rm II}{\rm Fe}^{\rm III}({\rm C}_{2}{\rm O}_{4})_{3}]\}_{\infty}}$ , abbreviated as BuZnFe, BuCoFe, and BuFeFe, respectively, are studied using thermogravimetry (TG) in the temperature range from ~300?K to ~675?K at multiple heating rates. This study also deals with how the thermal decomposition of the complexes proceed stepwise through a series of intermediate reactions. The effect of the divalent metal MII on the nature of thermal decomposition of the complexes, reflected in their TG profiles in terms of number of steps involved, is reported in this study. The temperature range of thermal decomposition steps for BuZnFe, BuCoFe, and BuFeFe with the same heating rates are studied systematically. Two different isoconversional methods, namely an improved iterative method and a model-free method are employed to calculate the kinetic parameters, and thus the most probable reaction mechanism of thermal decomposition is determined. Based on kinetic parameters, the important thermodynamic parameters such as the changes of entropy, enthalpy, and Gibbs free energy are estimated for the activated complex formation from the precursors. Considering the mass loss during the different thermal decomposition steps of BuZnFe, BuCoFe, and BuFeFe, observed in the thermogravimetry profiles, the overall reactions of the thermal decompositions are demonstrated. 相似文献
9.
10.
Yu. V. Bessmolniy G. Ya. Khadzhaj V. I. Beletskii D. V. Rokhmistrov R. V. Vovk I. L. Goulatis A. Chroneos 《Journal of Low Temperature Physics》2018,190(1-2):39-44
The thermal and electrical conductivity of a single-crystal \(\hbox {Cd}_{0.22}\hbox {Hg}_{0.78}\hbox {Te}\) was studied in the temperature range of practical applications (77–300 K). The sample has impurity conductivity, which is limited by the scattering of charge carriers by phonons. Heat in the sample is transferred by phonons and thermal conductivity is limited by phonon–phonon scattering. The electron contribution to the thermal conductivity can be neglected. 相似文献
11.
Geometric and electronic structures of \(\hbox {W}_{m}\hbox {Cu}_{n}\, (m + n \le 7)\) cluster have been systematically calculated by density functional theory at the generalized gradient approximation level for ground-state structures. \(\hbox {W}_{m}\hbox {Cu}_{n}\) clusters with \(n = 1, 3, 5\) tend to form bipyramid structures, whereas \(\hbox {WCu}_{n}\) favour planar shapes except for \(\hbox {WCu}_{5}\). The configurations of \(\hbox {W}_{m}\hbox {Cu}_{n}\) clusters are more sensitive to the Cu atoms than the W atoms, while the average atomic binding energies and the total magnetic moments are determined by W atoms. The calculated second-order differences in energies and HOMO–LOMO energy gaps show pronounced odd–even oscillating behaviours. From the Mulliken electron population analysis, we found that Cu 4p and W 6p orbitals exhibit electronic charges and both Cu 4s and W 6s orbitals transfer electronic charges to the W 5d orbital, which lead to the extension of W–Cu bond lengths. 相似文献
12.
We report on the thermoluminescence (TL) properties of \(\hbox {Y}_{2}{\mathrm {Si}}{\mathrm {O}}_{5}{:}\,{\mathrm {Ce}}^{3+}\) phosphor powder and thin films. For the phosphor powder, the TL intensity increases with an increase in UV dose for up to 20 min and then decreases. The TL intensity peak shifts slightly to higher-temperature region at relatively high heating rates, but with reduced peak intensity. Important TL kinetic parameters, such as the activation energy (E) and the frequency factor (s), were calculated from the glow curves using a variable heating rate method, and it was found that the glow peaks obey first-order kinetics. For the films, broad TL emissions over a wide temperature range with reduced intensity relative to that of the powder were observed. The maxima of the TL glow peaks of the films deposited in oxygen ambient and vacuum shift toward higher temperature relative to the TL peak position of the film deposited in an argon environment. Vacuum environment resulted in the formation of a deep trap relative to oxygen and argon environments. Furthermore, the structure of \(\hbox {Y}_{2}{\mathrm {Si}}{\mathrm {O}}_{5}{:}\,{\mathrm {Ce}}^{3+}\) phosphor powder transformed from \({x}_{2}\)-monoclinic polycrystalline phase to \({x}_{1}\)-monoclinic polycrystalline phase, for deposition at low substrate temperature. 相似文献
13.
Kenza Guenda T. Aaron Gulliver 《Applicable Algebra in Engineering, Communication and Computing》2013,24(6):445-459
We construct codes over the ring $\mathbb F _2+u\mathbb F _2$ with $u^2=0$ for use in DNA computing applications. The codes obtained satisfy the reverse complement constraint, the $GC$ content constraint, and avoid the secondary structure. They are derived from cyclic reverse-complement codes over the ring $\mathbb F _2+u\mathbb F _2$ . We also construct an infinite family of BCH DNA codes. 相似文献
14.
15.
Boufligha S. Mahamdioua N. Denbri F. Meriche F. Altintas S. P. Terzioglu C. 《Journal of Low Temperature Physics》2022,206(3-4):232-249
Journal of Low Temperature Physics - $${text{La}}_{0.7} {text{Ca}}_{0.18} {text{Ba}}_{0.12} {text{Mn}}_{0.95} {text{Sn}}_{0.05} {text{O}}_{{3{ }}}$$ compound has been successfully prepared by... 相似文献
16.
A novel, highly visible light active N-doped \(\hbox {WO}_{3}\) (\(\hbox {N}\)-\(\hbox {WO}_{3})\) is successfully synthesized via thermal decomposition of peroxotungstic acid–urea complex. The photocatalytic activity of \(\hbox {N}\)-\(\hbox {WO}_{3}\) is evaluated for the degradation of amaranth (AM) dye under visible and UVA light along with the role of reactive species, which has not yet been studied for \(\hbox {N}\)-\(\hbox {WO}_{3}\) photocatalysts. Doping of N into substitutional and interstitial sites of \(\hbox {WO}_{3}\) is confirmed by X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy. At a pH of 7, 1 g \(\hbox {l}^{-1}\) of \(\hbox {N}\)-\(\hbox {WO}_{3}\) can completely degrade \(10\,\hbox {mg } \hbox {l}^{-1}\) of AM within 1 h under visible and UVA light. For the degradation of AM by \(\hbox {N}\)-\(\hbox {WO}_{3}\) under visible and UVA light, \(\hbox {h}^{+}\) is found to be the main reactive species, while \(\cdot \hbox {OH}\) contributes to a lesser extent. On the contrary, \(^{1}\hbox {O}_{2}, \cdot \hbox {O}_{2}^{-}\) and \(\hbox {e}^{-}\) show negligible roles. The crucial role of \(\hbox {h}^{+}\) indicates effective suppression of electron–hole recombination after N doping. Dye sensitization and oxidation by reactive species are found to be the major pathway for the degradation of AM under visible and UVA light, respectively. 相似文献
17.
Joan-Josep Climent Pedro R. Navarro Leandro Tortosa 《Applicable Algebra in Engineering, Communication and Computing》2011,22(2):91-108
For a prime number p, Bergman (Israel J Math 18:257–277, 1974) established that
End(\mathbbZp×\mathbbZp2){{\rm End}(\mathbb{Z}_{p}\times \mathbb{Z}_{p^{2}})} is a semilocal ring with p
5 elements that cannot be embedded in matrices over any commutative ring. We identify the elements of
End(\mathbbZp ×\mathbbZp2){{\rm End}(\mathbb{Z}_{p} \times \mathbb{Z}_{p^{2}})} with elements in a new set, denoted by E
p
, of matrices of size 2 × 2, whose elements in the first row belong to
\mathbbZp{\mathbb{Z}_{p}} and the elements in the second row belong to
\mathbbZp2{\mathbb{Z}_{p^{2}}}; also, using the arithmetic in
\mathbbZp{\mathbb{Z}_{p}} and
\mathbbZp2{\mathbb{Z}_{p^{2}}}, we introduce the arithmetic in that ring and prove that the ring
End(\mathbbZp ×\mathbbZp2){{\rm End}(\mathbb{Z}_{p} \times \mathbb{Z}_{p^{2}})} is isomorphic to the ring E
p
. Finally, we present a Diffie-Hellman key interchange protocol using some polynomial functions over E
p
defined by polynomials in
\mathbbZ[X]{\mathbb{Z}[X]}. 相似文献
18.
Xiangyong Zeng Xishun Zhu Lei Hu 《Applicable Algebra in Engineering, Communication and Computing》2010,21(2):145-150
This note presents two new permutation polynomials with the form ${p(x)=\left(x^{2^k}+x+\delta\right)^{s}+x}$ over the finite field ${\mathbb{F}_{2^n}}$ as a supplement of the recent work of Yuan, Ding, Wang and Pieprzyk. 相似文献
19.
Mahmoud A. Hamad 《Journal of Superconductivity and Novel Magnetism》2016,29(6):1539-1543
The magnetocaloric effect is investigated for \(\text {Gd}_{\mathrm {5-}_{x}}\)Eu x Ge4 (0.25 ≤ x ≤ 2) system near a phase transition from a ferromagnetic to a paramagnetic state as a function of temperature with low external magnetic field change of 100 Oe. The sample with x = 1 has the smallest value of maximum magnetic entropy change and the specific heat change, and highest values of full-width at half-maximum and relative cooling power. The results indicate that the \(\text {Gd}_{\mathrm {5-}_{x}}\)Eu x Ge4 system has a prospective application for magnetic refrigerant in an extended high temperature range. Consequently, \(\text {Gd}_{\mathrm {5-}_{x}}\)Eu x Ge4 compounds are very attractive candidates for magnetic refrigeration applications, especially nitrogen liquefier. 相似文献
20.
Abdel Alim Kamal Amr M. Youssef 《Applicable Algebra in Engineering, Communication and Computing》2012,23(3-4):143-149
Climent et?al. (Appl Algebra Eng Commun Comput 22:91?C108, 2011) identified the elements of the endomorphisms ring End ${(\mathbb{Z}_p \times \mathbb{Z}_{p^2})}$ with elements in a set, E p , of matrices of size 2?× 2, whose elements in the first row belong to ${\mathbb{Z}_{p}}$ and the elements in the second row belong to ${\mathbb{Z}_{p^2}}$ . By taking advantage of matrix arithmetic, they proposed a key exchange protocol using polynomial functions over E p defined by polynomials in ${\mathbb{Z}[X]}$ . In this note, we show that this protocol is insecure; it can be broken by solving a set of 10 consistent homogeneous linear equations in 8 unknowns over ${\mathbb{Z}_{p^2}}$ . 相似文献