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91.
Rocio Marilyn Caja Rivera 《Mathematical Methods in the Applied Sciences》2019,42(18):6810-6828
Vector‐borne diseases, such as leishmaniasis, dengue, malaria, and yellow fever, transmitted by microparasites show periodic fluctuations in their prevalence. The novelty of this research is to assess the relationship between the vector feeding preference for an infectious host and the annual seasonal transmission through a vector‐host mathematical model. For the first time, numerical simulations illustrate that by increasing the vector feeding preference value in the transmission dynamics, periodic fluctuations accentuate and the endemic equilibrium average increases in vector and host populations. Moreover, increasing the vector feeding preference value, the amplitude strengthens for the infectious host and vector populations. This periodic behavior shows a similar pattern with the Peruvian incidence data from 2000 to 2016 for Andean cutaneous leishmaniasis provided by the Ministry of Health of Peru (MINSA). In addition, using the Floquet theory, the time average method and the linear operator method provides for the first time that the basic reproduction number for a nonautonomous system depends explicitly on the vector feeding preference for the infectious host. The nonautonomous model system shows that is a threshold parameter for the local stability of the disease‐free periodic solution. Therefore, the vector feeding preference is an important factor that should be considered and attended to for future research. Public and veterinary health in Peru and other countries should consider the vector feeding preference for specific host to vector control. 相似文献
92.
The LiRh-type crystal structure of the equiatomic intermetallic compound IrZn turns out to be a competitor to the otherwise energetically favored CsCl-type structures of congeneric transition metal zinc phases, thus enlightening the structural impact of element-specific factors beyond the Hume-Rothery concept. 相似文献
93.
分析了采用单一同轴磁场时强流相对论多注阴极的侧端发射问题,研究了在不同磁场内半径和多注漂移管长度情况下多注电子束的传输效率。研究发现:由于引导磁场尺寸有限,高压下多注阴极杆及多注阴极柱的电子束发射是影响多注电子束传输效率的主要因素,且该部分电子束对多注漂移管入口管壁的轰击直接影响了多注速调管的重频能力。设计了采用永磁铁和同轴磁场组合工作的强流相对论多注二极管,理论分析和模拟计算证明:基于组合磁场的多注二极管可明显减弱甚至抑制多注阴极发射球头以外的电子束发射,并且组合磁场的磁场位形和强度可满足强流相对论多注电子束的高效、稳定传输。 相似文献
94.
《International journal of quantum chemistry》2018,118(11)
The magnetic behavior of the fluorene bridged verdazyl diradicals has been studied theoretically in their neutral and deprotonated states. The deprotonation of C9‐H site of the fluorene ring opens a new coupling pathway, which changes the nature of magnetic coupling. The transmission spectra analysis reveals that the transmission through fluorine has also increased due to the opening of a new coupling path after deprotonation. 相似文献
95.
The microstructure of anisotropically shaped grains can strongly influence a range of material properties, including transport, mechanical and electro-optical. A grain-structure-related phenomenon, known as excluded volume epitaxy (EVE), is reported in this study. EVE is a local, inter-grain orientational correlations effect, which results from a combination of continuous nucleation of anisotropic grains and impingement of growing grains. Due to EVE, anisotropically shaped grains have a tendency to be similarly aligned in a local neighbourhood, despite the absence of any forced global orientation in the sample. The effect has been repeatedly observed by the authors in block copolymers, as illustrated by a representative TEM image. Optical microscopy of anisotropically shaped non-polymeric crystals revealed the generality of this effect. The simulation study revealed a tendency for azimuthal, inter-grain orientational correlation and re-confirmed the experimental observation of EVE. 相似文献
96.
Abstract Computer simulation studies of the energy distribution of transmitted ions such as alpha-particles, He-, and B-ions through crystalline silicon, using the enhanced binary-collision cascade simulator MARLOWE, will be reviewed. The enhancement includes an additional electronic-energy loss (EEL) model which takes into account explicitly both the target electron density variation via the structure factors and the electron density of the projectile. Investigations of the stopping power for He ions and protons in silicon, at intermediate- and high-energies, based on the adapted EEL model and a velocity-dependent effective charge will be presented. The overall agreement between the calculated and experimentally determined stopping power data and the simulated and measured transmission spectra will be demonstrated. Effects of energy-loss straggling, core-electron contribution to the energy loss at high-energies and charge-state effects at low energies on the transmission spectra will also be discussed. 相似文献
97.
Daniel Xu Andreas Tairych Iain A. Anderson 《Journal of Polymer Science.Polymer Physics》2016,54(4):465-472
Practice makes perfect to some extent. Research has shown that musicians who practice the piano for long periods of time can suffer a range of hand problems from loss of control to diminished speed. Now imagine a rubber keyboard that is springy, soft, and elastic. This is the new type of input device that dielectric elastomers (DE) can create. However their usage in large sensing systems is limited by a scalability challenge. Each DE sensor is married to a pair of connection cables and electronics, adding to the complexity of the background overheads. A new efficient multi‐frequency method is presented that is capable of detecting internal pressure changes from a difference in the DE's capacitance without the need for any additional wires or connections. This effectively segments the DE into smaller sections, achieving information from a single sensor equivalent to multiple sensors. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 465–472 相似文献
98.
99.
Lung-Hui Chen 《复变函数与椭圆型方程》2015,60(5):707-731
We study the inverse spectral problem in an interior transmission eigenvalue problem. The Cartwright’s theory in value distribution theory gives a connection between the distributional structure of the eigenvalues and the asymptotic behaviours of its defining functional determinants. Given a sufficient quantity of transmission eigenvalues, we prove a uniqueness of the refraction index in inhomogeneous medium as an uniqueness problem in entire function theory. The asymptotically periodical structure of the zero set of the solutions helps to locate infinitely many eigenvalues of infinite degree of freedom. 相似文献
100.
Sevtap Yildiz Faruk Yilmaz Haluk Özbek Önder Pekcan Koi˙chi˙ Ito 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(12):1573-1588
Random copolymers of poly(ethylene oxide) macromonomer with p‐vinylbenzyl end‐functional group (PEOVB) and liquid crystalline monomer, namely 6‐(4‐cyanobiphenyl‐4′‐oxy)hexyl acrylate (COA), were prepared by conventional free radical polymerization. A living anionic polymerization technique was employed for the synthesis of PEO macromonomers bearing p‐vinylbenzyl moiety at one end. The photon transmission method was also applied to study the phase transitions of COA monomer and its random copolymer with PEO. It was found that, for both samples, the nematic‐smectic A transition is continuous, but the critical fluctuation regions do not allow to obtain 3D XY values. Instead, we have obtained the values close to mean field regime. Scaling of thermal hystersis for random copolymer sample near the nematic‐isotropic transition was studied as well. Thermal hysteresis loops were produced under linearly varying temperature. It was shown that the areas of the hysteresis loops scale with the temperature scanning rate with an exponent being equal to 0.614 which is in good agreement with the field‐theoretical value. 相似文献