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141.
A. Alvarez F. R. Romero J. F.R. Archilla J. Cuevas P. V. Larsen 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,51(1):119-130
We study the dynamics of moving discrete breathers in an interfaced piecewise DNA molecule.
This is a DNA chain in which all the base pairs are identical and
there exists an interface such that the base pairs dipole moments at each side are oriented in opposite
directions.
The Hamiltonian of the Peyrard-Bishop model is augmented with a
term that includes the dipole-dipole coupling between base pairs.
Numerical simulations show the existence of two dynamical regimes.
If the translational kinetic energy of a moving breather launched
towards the interface is below a critical value, it is trapped in
a region around the interface collecting vibrational energy. For
an energy larger than the critical value, the breather is
transmitted and continues travelling along the double strand with
lower velocity. Reflection phenomena never occur.
The same study has been carried out when a single dipole is oriented
in opposite direction to the other ones.
When moving breathers collide
with the single inverted dipole, the same effects appear. These
results emphasize the importance of this simple type of local
inhomogeneity as it creates a mechanism for the trapping of
energy.
Finally, the simulations show that, under favorable conditions,
several launched moving breathers can be trapped successively at the interface
region producing an accumulation of vibrational energy. Moreover,
an additional colliding moving breather can produce a saturation
of energy and a moving breather with all the accumulated energy
is transmitted to the chain. 相似文献
142.
B. V. Beznosikov 《Journal of Structural Chemistry》2003,44(5):885-888
Crystal-chemical analysis of the structures of perovskite-like nitrides has been carried out. For cubic phases, the geometrical regions of existence and the most probable compositions have been determined. More than 80 new compounds have been predicted. 相似文献
143.
144.
Two-phase flow and capillarity phenomenon in porous solids, well known in physics and engineering, are treated from a rigorous continuum thermomechanical point of view for the first time. A ternary model, consisting of a porous solid phase, a liquid phase, and a gas phase, is investigated within the framework of thermodynamics. The main result of the evaluation of the entropy principle turns out to be that the interaction forces between the solid, gas, and liquid phases are dependent on the free Helmholtz energy functions of the corresponding phases and on the gradient of the liquid density. The classical result for the driving volume force for raising a water column in a narrow tube against the force of gravity is contained in the general investigation. 相似文献
145.
Selective reagent ionisation‐time of flight‐mass spectrometry: a rapid technology for the novel analysis of blends of new psychoactive substances 下载免费PDF全文
Matteo Lanza W. Joe Acton Philipp Sulzer Kostiantyn Breiev Simone Jürschik Alfons Jordan Eugen Hartungen Gernot Hanel Lukas Märk Tilmann D. Märk Chris A. Mayhew 《Journal of mass spectrometry : JMS》2015,50(2):427-431
In this study we demonstrate the potential of selective reagent ionisation‐time of flight‐mass spectrometry for the rapid and selective identification of a popular new psychoactive substance blend called ‘synthacaine’, a mixture that is supposed to imitate the sensory and intoxicating effects of cocaine. Reactions with H3O+ result in protonated parent molecules which can be tentatively assigned to benzocaine and methiopropamine. However, by comparing the product ion branching ratios obtained at two reduced electric field values (90 and 170 Td) for two reagent ions (H3O+ and NO+) to those of the pure chemicals, we show that identification is possible with a much higher level of confidence then when relying solely on the m/z of protonated parent molecules. A rapid and highly selective analytical identification of the constituents of a recreational drug is particularly crucial to medical personnel for the prompt medical treatment of overdoses, toxic effects or allergic reactions. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
146.
《Journal of mass spectrometry : JMS》2017,52(10):633-637
Differentiation of new psychoactive substance (NPS), 6‐(2‐methylaminopropyl)benzofuran (6‐MAPB), and its positional isomer, 2‐(2‐methylaminopropyl)benzofuran (2‐MAPB), by means of gas chromatography/mass spectrometry (GC/MS) with quadrupole detection is ambiguous. Reliable distinguishing of the two isomers could be achieved by MS/MS spectra recorded after collision‐induced dissociation (CID) of precursor ions. Both electron ionization (EI) and electrospray ionization (ESI) methods could be used for these purposes. 相似文献
147.
Shoukry El-Ganaini 《Journal of the Egyptian Mathematical Society》2017,25(1):19-27
In this paper, the first integral method combined with Liu's theorem is applied to integrate a new coupled nonlinear Schrodinger type equation. Using this combination, more new exact traveling wave solutions are obtained for the considered equation using ideas from the theory of commutative algebra. In addition, more solutions are also obtained via the application of semi-inverse variational principle due to Ji-Huan He. The used approaches with the help of symbolic computations via Mathematica 9, may provide a straightforward effective and powerful mathematical tools for solving nonlinear partial differential equations in mathematical physics. 相似文献
148.
利用辅助方程与函数变换相结合的方法,构造了Degasperis-Procesi(D-P)方程的无穷序列类孤子新解.首先,通过两种函数变换,把D-P方程化为常微分方程组.然后,利用常微分方程组的首次积分,把D-P方程的求解问题化为几种常微分方程的求解问题.最后,利用几种常微分方程的Bcklund变换等相关结论,构造了D-P方程的无穷序列类孤子新解.这里包括由Riemannθ函数、Jacobi椭圆函数、双曲函数、三角函数和有理函数组成的无穷序列光滑孤立子解、尖峰孤立子解和紧孤立子解. 相似文献
149.
给出辅助方程、函数变换与变量分离解相结合的方法,构造了具任意次非线性项的Camassa-Holm方程的双孤子和双周期新解.首先,通过两个辅助方程、函数变换与变量分离解,将具任意次非线性项的Camassa-Holm方程的求解问题转化为非线性代数方程的求解问题.然后,借助符号计算系统Mathematica求出该方程组的解,并用辅助方程的相关结论,构造了双周期解和双孤子新解. 相似文献
150.
基于低温物理效应的新型超高精度陀螺仪研究综述 总被引:3,自引:2,他引:3
综述了基于低温玻色—爱因斯坦凝聚状态新物理效应的量子陀螺和超流体陀螺的研究动态。对两类新原理陀螺所使用的物理效应、工作原理、技术现状等方面进行了阐述。量子陀螺依据物质波的Sagnac效应测量角速率,具有比光学陀螺高若干数量级的测量精度;基于超流体低粘性和量子涡旋特性的超流体陀螺,原理上有望达到超高精度。最后分析了两类陀螺的发展前景。 相似文献