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61.
Frank H.G.M. Wijnands Charles G. Crookes Paul M. Charles Richard M. Ash Ian F. Lealman Michael J. Robertson Anthony E. Kelly Kevin A. Williams Aeneas B. Massara Richard V. Penty Ian H. White 《Optical and Quantum Electronics》2002,34(10):959-973
An anomalous modulation in the wavelength spectrum has been observed in lasers with spot-size converters. This intensity modulation is shown to be caused by beating between the fundamental lasing mode and radiation modes in the taper. This results in a periodic modulation in the net gain spectrum, which causes wavelength jumps between adjacent net gain maxima, and a drive current dependent spectral width that is expected to affect system performance. The amplitude of this spectral modulation is reduced significantly by either using an angled rear-facet which reflects the beating radiation modes away from the laser axis, or by using a nonlinear, adiabatic taper. 相似文献
62.
P. Paasche T. Valenzuela D. Biswas C. Angelescu G. Werth 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(3):295-300
We have examined experimentally the motional spectrum of an electron cloud confined in a Penning trap. When the axial oscillation
is excited by a radio frequency field the resonance exhibits a double structure. Both components depend differently on the
number of trapped electrons and have different shape and width. We conclude that one of them corresponds to the excitation
of the individual electrons while the other is the center-of-mass mode of the cloud. The threshold behaviour of the center-of-mass
resonance suggests that it is a parametric instability of a Mathieu type equation of motion.
Received 11 July 2001 and Received in final form 12 November 2001 相似文献
63.
Investigation of remelting and cladding processing with laminar plasma jets on several metals has been conducted looking for possible development of a new surface modification technique. The remelting tests illustrated that the new method could evidently improve the material microstructure and properties of cast iron. The cladding was done with Al2O3 ceramic powder on stainless steel. The energy dispersive spectra (EDS) analysis was used to determine the distribution of the major cladding element in the plasma-processed layers, for which the microstructure observations and hardness measurements were also performed. 相似文献
64.
We study the propagation of the light mesons σ,ω,ρ, and a0(980) in dense hadronic matter in an extended derivative scalar coupling model. Within the scheme proposed it is possible
to unambiguously define effective density-dependent couplings at the Lagrangian level. We first apply the model to study asymmetric
nuclear matter with fixed isospin asymmetry, and then we pay particular attention to hypermatter in β-equilibrium. The equation
of state and the potential contribution to the symmetry coefficient arising from the mean-field approximation are investigated.
Received: 16 October 2001 / Accepted: 10 January 2002 相似文献
65.
Masanobu Haraguchi David F. P. Pile Toshihiro Okamoto Masuo Fukui Dmitri K. Gramotnev 《Optical Review》2006,13(4):228-230
We have numerically shown the existence of coupled wedge plasmons (CWPs) which propagates along a nano gap of a twin metal
wedge. The CWPs are formed by wedge plasmons which can interact with each other. The dispersion relations of the wavenumber,
propagation distance, and beam area of CWPs, are described and show that the characteristics of CWPs are similar to those
of wedge plasmons and of gap plasmons. We also propose a new plasmon waveguide composed of twin metal wedges with a nano gap. 相似文献
66.
研制了一台五通道ROSS-FILTER-PIN软X射线能谱仪,能谱范围为0.28—1.56keV.它由5个连续能段组成,每个能段的起止边由罗斯滤片对(ROSS-FILTERS)的L或K吸收边确定.罗斯滤片对的厚度通过优化计算得到,为了使每个通道的灵敏区外响应(即所测能段外响应)与通道总响应之比最小,在滤片对的第二滤片上镀上了一定厚度的第一滤片材料;为了缩减滤片表面积以增强低能滤片的抗冲击能力及方便滤片加工,能谱仪采用了小探测面积的PIN探测器(1mm2).借助此能谱仪,测量得到了喷气式Z箍缩(Z-pinch)等离子体辐射软X射线能谱的分布,并研究了软X射线产额随箍缩状况的变化趋势.
关键词:
Z箍缩等离子体
罗斯滤片
软X射线能谱 相似文献
67.
Luca Lambertini Raimondello Orsini 《Central European Journal of Operations Research》2007,15(1):105-117
We reconsider the role of network externalities in a dynamic spatial monopoly where the firm must invest in order to accumulate
capacity, while consumers may have either linear or quadratic preferences. We (1) characterise saddle point equilibria, (2)
prove that the extent of market coverage is increasing in the network effect and (3) unlike the existing static literature
on the same problem, the monopolist may not make introductory price offers. Then, we briefly deal with the socially optimal
solution, showing that, in general, a planner would serve more consumers than a profit-seeking monopolist.
相似文献
68.
������������Ƶ�����ܼ�Ramanɢ�������Ƿֲ����� 总被引:1,自引:1,他引:0
介绍了在神光Ⅱ装置上开展的长脉冲2ns三倍频激光与黑腔靶相互作用的实验。报道了采用PIN探测器阵列测量大角度受激Raman散射(SRS)角分布和采用激光卡计对背向SRS光能量积分测量的实验结果。相同实验条件下激光辐照缝靶产生的SRS光能量要强于激光与全腔靶作用产生的SRS光,小腔靶的SRS光能量要强于标准腔靶。对比长脉冲2ns及短脉冲1ns激光打靶实验结果可以看出:由于激光功率密度的下降,长脉冲激光打靶时SRS散射光能量要弱于短脉冲激光打靶。长脉冲2ns激光与标准腔靶相互作用时,等离子体堵腔比较严重。 相似文献
69.
The possibility that pairs of quarks will form diquark clusters in the regime above deconfinement transition for hadron matter
at finite density is revisited. Here we present the results on the diquark-diquark (dq-dq) interaction in the framework of
constituent quark model taking account of spin, isospin and color degrees of freedom in the spirit of generalized Pauli principle.
By constructing the appropriate spin and color states of the dq-dq clusters we compute the expectation values of the interaction
Hamiltonian involving pairwise quark—quark interaction. We find that the effective interaction between two diquark clusters
is quite sensitive to different configurations characterized by color and spin states, obtained after the coupling of two
diquark states. The value of the coupling parameter for a particular color—spin state, i.e., -3, 1 is compared to the one
obtained earlier by Donoghue and Sateesh,Phys. Rev.
D38, 360 (1988) based on the effective Φ4-theory. This new value of λ derived for different color-spin dq-dq states, may lead to several important implications in
the studies of diquark star and diquark gas. 相似文献
70.
A one-dimensional nanodusty plasma was modeled by self-consistently coupling a plasma model with nanoparticle growth, charging,
and transport models. As nanoparticles grow from subnanometer to tens of nm in diameter, the numerical results predict a rich
spatiotemporal structure, including four distinct temporal phases: a charge-limited phase, a charge accumulation phase, an
early ion drag phase, and a sheath interaction phase. 相似文献