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141.
The formation of charged pion condensate in anti-parallel electromagnetic fields and in the presence of the isospin chemical potential is studied in the two-flavor Nambu-Jona-Lasinio model.The method of Schwinger proper time is extended to explore the quantities in the off-diagonal flavor space,i.e.the charged pion.In this framework,π^± are treated as bound states of quarks and not as point-like charged particles.The isospin chemical potential plays the role of a trigger for charged pion condensation.We obtain the associated effective potential as a function of the strength of the electromagnetic fields and find that it contains a sextic term which possibly induces a weak first order phase transition.The dependence of pion condensation on model parameters is investigated. 相似文献
142.
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144.
We developed a novel microfluidic cell culture device in which magnetic beads repetitively collide with osteoblast cells, MC3T3‐E1, owing to attractive forces generated by pulsed electromagnetic fields and consequently the cells were physically stimulated by bead impacts. Our device consists of an on‐chip microelectromagnet and a microfluidic channel which were fabricated by a microelectromechanical system technique. The impact forces and stresses acting on a cell were numerically analyzed and experimentally generated with different sizes of bead (4.5, 7.6 and 8.4 μm) and at various pulse frequencies (60 Hz, 1 kHz and 1 MHz). Cells were synchronized at each specific phase of the cell cycle before stimulation in order to determine the most susceptible phase against bead impacts. The cells were stimulated with different sizes of bead at various pulse frequencies for 1 min at G1, S and G2 phases, respectively, and then counted immediately after one doubling time. The growth rate of cells was highly accelerated when they were stimulated with 4.5 μm beads at G1 phase and a pulse frequency of 1 MHz. Almost all of the cells were viable after stimulation, indicating that our cell stimulator did not cause any cellular damage and is suitable for use in new physical stimulus modalities. 相似文献
145.
We use the improved Faddeev-Jackiw quantization method to quantize the electromagnetic field and its Lagrange multiplier fields. The method's comparison with the usual Faddeev-Jackiw method and the Dirac method is given. We show that this method is equivalent to the Dirac method and also retains all the merits of the usual Faddeev-Jackiw method. Moreover, it is simpler than the usual one if one needs to obtain new secondary constraints. Therefore, the improved Faddeev-Jackiw method is essential. Meanwhile, we find the new meaning of the Lagrange multipliers and explain the Faddeev-Jackiw generalized brackets concerning the Lagrange multipliers. 相似文献
146.
147.
R. Giovanelli 《Il Nuovo Cimento D》1987,9(11):1443-1460
Summary Using the Boris mover, or other standard methods, the error pile-up in the computation of the relativistic orbit of charged
particles in electric and magnetic fields becomes quickly excessive, if one wants to keep reasonably limited the number of
points employed to build the particle orbit. An analytical solution becomes, therefore, desirable and its construction is
the subject of the present work.
Riassunto Unsando il metodo di Boris, oppure altri metodi standard, l'accumulazione degli errori nella determinazione numerica delle orbite relativistiche di particelle cariche in campi elettrici e magnetici diventa intollerabile, se il numero dei punti impiegati per costruire le orbite stesse è mantenuto basso. Una soluzione analitica diviene quindi utile, e questa costituisce l'argomento del presente lavoro.
Резюме В рамках стндартных методов погрешность при вычислении релятивистской орбиты заряженных частиц в электронном и магнитном полях становится чрезмерно большой, если для построения орбиты часицы используется ограниченное число точек. В связи с этим конструируется аналитическое решение.相似文献
148.
The rectangular dielectric waveguide is the most commonly used structure in integrated optics, especially in semi-conductor
diode lasers. Demands for new applications such as high-speed data backplanes in integrated electronics, waveguide filters,
optical multiplexers and optical switches are driving technology toward better materials and processing techniques for planar
waveguide structures. The infinite slab and circular waveguides that we know are not practical for use on a substrate because
the slab waveguide has no lateral confinement and the circular fiber is not compatible with the planar processing technology
being used to make planar structures. The rectangular waveguide is the natural structure. In this review, we have discussed
several analytical methods for analyzing the mode structure of rectangular structures, beginning with a wave analysis based
on the pioneering work of Marcatili. We study three basic techniques with examples to compare their performance levels. These
are the analytical approach developed by Marcatili, the perturbation techniques, which improve on the analytical solutions
and the effective index method with examples.
T Srinivas received the B.Sc. (Hon.) degree from Nehru Science College, Hydrabad and M.E. (Int.) and Ph.D. dgrees from the Indian Institute
of Science, Bangalore, India. He was a Postdoctoral Research Fellow at Toyohashi University of Technology, Japan from 1992
to 1996. He is currently an Associate Professor with the Department of Electrical Communication Engineering, Indian Institute
of Science. His areas of interests are optical communication networks, integrated optics, micro-opto-electrical-mechanical
systems (MOEMS) and fiberoptic sensors 相似文献
149.
圆形面偶极层与圆电流的电磁场 总被引:12,自引:7,他引:5
通过解电场的轴对称边值问题求出了圆形面偶极层的电势分布,使用其结果和类比方法找到了圆电流的磁场分布。 相似文献
150.