General Requirements for a Relativistic Quantum Theory

The equations of a relativistic quantum theory for two or more particles should satisfy at least the following criteria. (1) They should be Poincaré invariant. (2) The cluster property should hold. (3) Causality should not be violated over distances much larger than the Compton wavelengths of the particles involved. (4) The electromagnetic interaction between charged particles should be formulated in a gauge-invariant way. (5) If, for a two-particle system, one of the masses becomes infinitely large, the equations should reduce to the relevant relativistic equation for the other particle. (6) In the nonrelativistic limit the equation should reduce to the Schr?dinger equation. In this paper it will be shown how a quasi-potential theory, which was introduced many years ago [1] and which was applied to a number of systems [2–12], meets all these requirements. Received March 25, 1997; revised July 15, 1997; accepted for publication March 18, 1998     

Experimental Test of the Evans’ <Emphasis Type="Italic">B</Emphasis>(3)-Field: Measuring the Interaction with Free Electrons

During the past decade, M.W. Evans and his coworkers have been developing so-called “Evans” or “ECE theory” that intends to serve as an unified field theory. One of its predictions is an existence of a radiation magnetic field called a “B(3)-field” which should accompany a circularly polarized electromagnetic radiation. This field should affect free electrons in two ways: (1) the electrons should behave in the B(3)-field in the same way as in a classical magnetic field (i.e., Larmor precession) and moreover, (2) the electrons should undergo quantum interaction with the B(3)-field with the formation of a spin connection resonance. This paper presents an experimental test of the B(3)-field existence by observing the changes in trajectories of free electrons in special detector, when strong (up to 200 W/m²) continuous circularly polarized microwave radiation of a frequency of 2.45 GHz is applied. We have not detected any sign of B(3)-field in presented experiment. It follows that if the B(3)-field really exists, it should be at least 4 orders of magnitude smaller than the Evans’ theory predicts.     

Enhancement and inversion of an alternating-current electric field in a finely dispersed dielectric

It has been found that a sinusoidal electric field is enhanced by a factor of more than 10³ in two plane-parallel layers of different dielectrics placed between plates of a parallel-plate capacitor. The implementation of the enhancement of the electric field requires that the following two conditions should be satisfied: (1) one of the two layers should consist of finely dispersed dielectric particles with ionized donor centers formed on their surface and free electrons in their bulk, and (2) the dielectric permittivity of the powder should have a negative value. It has also been found that, in the powder layer, the enhancement of the electric field occurs simultaneously with its inversion.     

Self-contained Kondo effect in single molecules

Kondo coupling of and conduction electrons is a common feature of f-electron intermetallics. Similar effects should occur in carbon ring systems (metallocenes). Evidence for Kondo coupling in Ce(C(8)H(8)(2) (cerocene) and the ytterbocene Cp*(2) Yb(bipy) is reported from magnetic susceptibility and L(III)-edge x-ray absorption spectroscopy. These well-defined systems provide a new way to study the Kondo effect on the nanoscale, should generate insight into the Anderson Lattice problem, and indicate the importance of this often-ignored contribution to bonding in organometallics.     

Inverted regions induced by geometric constraints on a classical encounter-controlled binary reaction

A two-dimensional Cellular Automata model is proposed to simulate the exit dynamics of occupant evacuation. Concerning the exit width and the door separation, we put forward some useful standpoints: (1) exit width should be bigger than a critical value, and the door separation should be neither too small nor too big; (2) for single-exit door, with the increase of exit width, the flux per unit width will decrease but the total flux will always increase; (3) the total flux of the exit is an increasing nonlinear function of the exit width; (4) the optimal value of the door separation does not vary with the value of exit width; (5) the layout of exits should be symmetry. Those results are helpful in performance-based design of building.     

延迟击穿半导体开关二极管最佳参数确定

 分析了延迟击穿二极管（DBD,delayed breakdown diode)的物理机理。从该器件在负载上的输出脉冲幅度及上升时间两方面综合考虑,通过改变器件结构参数和物理参数（长度、面积、掺杂浓度、激励源等）,模拟研究了不同激励源及不同负载情况下DBD特性的变化情况。结果表明: 上升时间对于面积和负载电阻均存在极小值,设计时面积和负载电阻应该选取该极值点对应的最佳值。n区长度存在最佳值,理论上应为器件加载在所需临界击穿电压值而且刚好处于穿通状态时的长度值;p+区和n+区的长度没有太大的影响,但应稍大于各自的穿通长度,浓度则尽量高;n区掺杂浓度越低越好,对激励源要求电流稍高于临界条件即可。     

Absorption of surface polaritons by molecules near the surface of a metallic slab

The cross section for absorption of surface polaritons (SP) by molecules above a metallic slab is calculated quantum mechanically. It shows a strong dependence on the thickness of the slab. This feature, even more pronounced, should also appear in more complex processes involving SP. It is also argued that SP guided by thin metallic films should be a useful tool in the spectroscopy of absorbates.     

The effect of the group propagation of waves on the spectral behaviour of a multilayer Ar coating

As the monitoring wavelength detected by an optical monitor (photometer) is inevitably of a considerable spectral width, it should be travelling as a group of waves rather than a monochromatic wave. In addition, the photometer is influenced simultaneously by the waves’ combined effect. The phases of the disturbance of different wavelengths travelling with the group velocity are in good agreement. Therefore, the phase thickness(es) of the monitored layer(s) should be modulated by the group factor. The effect of the new thickness(es) is investigated and the close correlation between theoretically predicted and experimental results is presented.     

Calculation of geometries and chemisorption energies of adatoms on simple metals

We report results of calculations with a formalism that in principle applies quite generally for chemisorption on a real metallic substrate. Including the substrate structure within perturbation theory on a self-consistent jellium-plus-adatom calculation, we have computed the dependence of the binding energy of an adatom on the surface geometry. Specifically, in the case of hydrogen on Al, our model calculation predicts that the stable positions are bridge configurations on the (100) and (110) surfaces and atop positions on the (111) surface, and that they have almost the same heats of chemisorption (1.8–2.0 eV). For geometrical reasons the bridge configuration seems to be a reasonable result while the atop result for the (111) surface is more uncertain. Thus, chemisorption of H on Al should require predissociation of the H₂ gas. In addition, the predicted values for hydrogen desorption imply that measurements on H on Al surfaces should be performed at low temperatures to avoid desorption. Results for H on a jellium of Na density indicates that hydrogen should be absorbed in rather than adsorbed on Na metal.     

Can induced theta vacua be created in heavy-Ion collisions?

We discuss a phenomenon important to the development of the early Universe which may be experimentally testable in heavy-ion collisions. An arbitrary induced straight theta vacuum state should be created in heavy-ion collisions, similar to the creation of the disoriented chiral condensate. It should be a large domain with a wrong straight theta(ind) not equal0 orientation which will mimic the physics of the early Universe when it is believed that the fundamental parameter straight theta(fund) not equal0. We test this idea numerically in a simple model where we study the evolution of the phases of the chiral condensates in QCD with two quark flavors with nonzero straight theta(ind) parameter. We see the formation of a nonzero straight theta(ind) vacuum on a time scale of 10(-23) s.     

On phase transitions in cold nuclear matter

Real conditions for the formation of cold subhadronic matter are considered with allowance for nontrivial properties of the QCD vacuum. It is shown that a steady state of this matter is attainable, if at all, only in the case where dynamical (massive) quarks exist as rather stable quasiparticles. This state may consist of both a degenerate nearly perfect gas of these particles and a degenerate gas of current quarks in the interior of some (compact) neutron stars. In the latter case, both phases should coexist, and the first phase should occupy a certain space between the second phase and (normal) hadron matter occurring at the periphery of the star.     

Propagation of self-gravitating density waves in the deDonder gauge: the physical importance of gauge solutions and the problem of initial conditions

The propagation of perturbations on a spatially flat Robertson-Walker background is studied within linear perturbation theory in deDonder gauge and for comparison in synchronous gauge. The metric perturbations should be determined uniquely by the density/pressure perturbations, therefore only two initial conditions, namely for the density contrast and its time derivative, should be needed. Since the number of fundamental solutions for the density perturbations is higher than 2 in both gauges (6 resp. 3) an additional reduction of possible initial conditions, resp. a physically motivated exclusion of solutions, is needed. It is shown that the common treatment of excluding the so-called gauge solutions (solutions which can be gauged to zero in an already chosen gauge) leads to unphysical results. If gauge solutions are excluded the density perturbation solutions are the same in both gauges. But the correct Newtonian limit — which is present in deDonder gauge but not in synchronous gauge — is bound to the differences in the two gauges for large spatial scales of perturbations. Furthermore, compressional wave solutions should vanish for infinite spatial scales of perturbations (isotropy), but this is guaranteed in deDonder gauge by gauge solutions again. Gauge solutions should therefore not be taken as unphysical.     

一种实用的准单色光退偏器的研究

用矩阵方法对一种准单色光退偏器Ｌｙｏｔ改进型退偏器进行了详细的理论分析，得到了该退偏器的有效退偏条件为：１）退偏器的总延迟必须足够大；２）晶体楔角或通光孔径必须足够大；３）二晶体光轴夹角必须是４５°。实验表明，该退偏器在４００～８００ｎｍ宽光谱范围内对±１０ｎｍ的任意准单色偏振光进行退偏后，平均的残余偏振度小于１．２％。     

A businessman's survey of light-wave electronics

Optical transmissions should gradually displace conventional cables in most electronics signal circuitry. Given further progress in integrated optics, light-wave transmission will become the dominant method of signal transmission. Its fundamental advantages are (1) bandwidth, (2) electrical isolation, and (3) potentially low cost. Certain technologies will probably predominate. Single-fiber channels should be favored over fiber bundles. Graded-index fibers will probably be favored over step-index fibers. And semiconductor lasers should eventually displace light-emitting diodes as the primary light source. The three biggest obstacles to these developments are cost, component availability, and inertia among original equipment manufacturers' (OEM) designers.     

Impact of Viscosity on DNA Dynamics

We study the influence of viscosity on DNA dynamics. By employing the nonlinear Peyrard-Bishop-Dauxois （PBD） model, it is shown that the DNA dynamics can be explained by a solution of a complex nonlinear Schrǒdinger equation （CNLSE）. This is the nonlinear Schrǒdinger equation （NLSE） with a nonlinear parameter being a complex number. We compare real and imaginary parts of this nonlinear parameter and show that the latter one should not be negligible, which means that the CNLSE should be solved numerically,     

Universality class of fluctuating pulled fronts

It has recently been proposed that fluctuating "pulled" fronts propagating into an unstable state should not be in the standard Kardar-Parisi-Zhang (KPZ) universality class for rough interface growth. We introduce an effective field equation for this class of problems, and show on the basis of it that noisy pulled fronts in d+1 bulk dimensions should be in the universality class of the ((d+1)+1)D KPZ equation rather than of the (d+1)D KPZ equation. Our scenario ties together a number of heretofore unexplained observations in the literature, and is supported by previous numerical results.     

5-GHz repetition-rate dual-wavelength pulse-train generation from an intracavity frequency-modulated Er-Yb:glass laser: errata

In our recent Letter,(1) the affiliation of the authors was incorrect and should read as shown above. On p. 1549, in line 19 of the left-hand column the word "pulse" should be replaced with "trace." Finally, in Ref. 11 the name of the first author was misspelled. The correct reference should read as follows:     

Transmission phase shift of a quantum dot with kondo correlations

We study the effects of Kondo correlations on the transmission phase shift of a quantum dot in an Aharonov-Bohm ring. We predict in detail how the development of a Kondo resonance should affect the dependence of the phase shift on transport voltage, gate voltage, and temperature. This system should allow the first direct observation of the well-known scattering phase shift of pi/2 expected (but not directly measurable in bulk systems) at zero temperature for an electron scattering off a spin- 1 / 2 impurity that is screened into a singlet.     

Poincare surface of section and quantum scattering

A very simple model for the quantum-mechanical scattering of a particle is studied with a dual goal: The chaotic nature of the corresponding classical problem should be quite obvious, and the method of solution should use an approach that is closely related to the surface of section in classical mechanics. Moreover, the mathematical operations should be elementary so that the errors in a semiclassical approximation or in any computational work have a chance of being controllable. Finally, the mode of presentation is such as to be understandable for a newcomer to the field of chaos. The model is a variation of the Sinai billiard where the circular hard wall inside a box (parallelogram) is replaced by a trombone-shaped surface for the particle to enter and exit the box. The rim (circular boundary between trombone and box) is the surface of section, with the total current at fixed energy in either direction providing the measure for the wave functions. The Poincare map then becomes the product of two unitary transformations, where the first is diagonal in angular momentum, while the second is diagonal in angle.     

Modeling of single- and multimode photonic-crystal planar waveguides with the plane-wave admittance method

One-foil targets emit most transition radiation (TR) power in storage ring synchrotrons. Such one-foil TR emitting targets (OFTRTs) are optimized, with respect to the foil material and the foil thickness, for use as X-ray lithography (XRL) sources. The best possible elemental material and the foil thickness of OFTRTs for XRL are determined for our storage ring synchrotrons MIRROIRCLE-20SX and MIRRORCLE-6X, which operate with electrons accelerated to 20 MeV and 6 MeV, respectively. It is shown that the XRL efficiency of a OFTRT, with an optimum thickness, increases when the elemental foil material has a lower atomic number Z. The best elemental OFTRT, for performing XRL by MIRRORCLE-20SX, should contain one Be foil with a thickness of d≅240 nm, while the second best OFTRT should be made of one C foil with d≅220 nm. The best elemental OFTRT, for performing XRL by MIRRORCLE-6X, should contain one C foil with d≅35 nm, while the second best OFTRT should be made of one Be foil with d≅100 nm, because there are no thinner Be foils. The XRL efficiency of a C-foil OFTRT increases when a higher-density foil is used. A OFTRT containing one foil of a given material with optimum thickness, in MIRRORCLE-20SX, has approximately 100 times larger XRL efficiency in comparison with such a target in MIRRORCLE-6X. PACS 41.50.+h; 29.25.-t; 81.16.Nd; 41.60.Ap; 29.20.Dh