The Vibrational Spectra of Complexes with Planar Monothiooxamides. III. The Palladium(II) Complexes of Neutral Monothiooxamides

The new complexes trans-[PdX₂(H₄MTO)2] (X = Cl, Br, I), trans-[PdX₂(H₃MMTO)2] (X = Cl, Br, I), trans-[PdX₂(SH₃)2] (X = Cl, Br), [Pd(H₄MTO)₄]CI₂ and [Pd(H₃MMTO)₄]CI₂, where H₄MTO = monothiooxamide, H₃MMTO = N(o)-methylmonothiooxamide and SH₃ = N(s)-methylmonothiooxamide, have been prepared. The complexes were characterized by elemental analyses, conductivity measurements, X-ray powder patterns, thermal methods and spectroscopic (UV/VIS, FT-IR, Laser-Raman) studies. The vibrational analysis of the complexes is given using NH/ND and CH₃/CD₃ isotopic substitutions. Monomeric square planar structures are assigned for the complexes in the solid state. The neutral monothiooxamides behave as monodentate ligands coordinating through their thioamide sulfur atom. The complex [Pd(SH2)2] was isolated during the thermal decomposition of trans-[PdCl₂(SH₃)₂].     

The Vibrational Spectra of Complexes with Planar Monothiooxamides. IV. The Copper(II) and Copper(I) Complexes of Neutral Monothiooxamides

The new complexes CuX₂(LH₂), CuX₂ (SH₃) (X = Cl, Br), CuX(LH₂), CuX(SH₃) (X = Cl, Br, I), CuX(H₄MTO)₂ (X = Cl, Br), Cul(H₄MTO) and CuX(H₃MMTO)₂ (X = Cl, Br, I), where LH₂ = N.N′-dimethyl-monothiooxamide, SH₃ = N(s)-methylmonothiooxamide, H₄MTO = monothiooxamide and H₃MMTO = N_(o)-methylmonothiooxamide, have been prepared. The complexes were characterized by elemental analyses, conductivity measurements, magnetic moments and spectroscopic (UV/VIS, FT-IR, Laser-Raman) studies. The vibrational analysis of the complexes has been given using NH/ND, CH₃/CD₃ and ⁶³cu/⁶⁵cu isotopic substitutions. The neutral monothiooxamides behave as monodentate ligands in the Cu(I) complexes coordinating through their thioamide sulfur atom. The ligands LH2 and SH₃ act as bidentate chelating agents in the Cu(II) complexes with ligated atoms being the thioamide sulfur and the amide oxygen.     

A Modified Version of the Grimm's Glow Discharge Lamp for Use as a Demountable Hollow Cathode Emission Source. II. The Current Intensity-Voltage Characteristic Curves

The dependence of resulting voltage on applied current intensity in a modified commercially available hollow cathode lamp is determined in the case of aluminium, copper and graphite cathodic materials in an extended range of argon carrier gas pressures and for five different cathode - anode distances. Experimental results show that the modified emission source affords high stability discharge in a wide range of experimental parameters.     

基于平移不变壳模型的轻核(A≤6)基态特性

包含中心力、张量力、自旋-轨道力和四级自旋-轨道力且具有高斯型径向关系的唯象核子-核子相互作用被构造并通过调节有关参数来得到氘核结合能、均方根半径、D态几率、磁偶极矩和电四极矩的理论值和实验值之间的最好拟合.氘核基态波函数用对应主量子数0≤N≤1 0的平移不变壳模型基函数来展开.另外,用新的相互作用还计算了³H ,⁴He,⁵He和⁶Li核的结合能、均方根半径和磁偶极矩.这些核的波函数也是用平移不变壳模型基函数来展开,只是对前两个核,N=10;对⁵He,N=7;对⁶Li,N=6.对氘核,进一步研究了三体力的作用.所得结果与相应的实验数据符合甚好.     

Energy levels of terbium(III) in the elpasolite Cs2NaTbBr6. II. A correlation crystal field analysis

A set of more than 100 electronic energy levels in Cs₂NaTbBr₆, extending from the ground state to ⁵H₄, is used to test different models of the correlation crystal field (CCF). These are based on Judd's orthogonal g_iQ ^(k) two-electron operators, and more specifically on contributions due to spin-correlation, or ligand polarization. Similar data from Cs₂NaTbCl₆ and Cs₂NaTbF₆ has also been analysed. Only fourth-rank operators make clear improvements to the quality of the fit in deviant multiplets. Empirically the g₇ ⁽⁴⁾ and g₉ ⁽⁴⁾ operators are found to be the most effective. Although fourth-rank operators achieve modest success in correcting the calculated spread of the multiplets, no single operator has a significant impact on the shortcomings of the one-body crystal field. This result is discussed in terms of the limitations of an effective-operator Hamiltonian.     

Solid-state active media of tunable organic- compound lasers pumped with a laser. II. A copper vapor laser

The lasing properties of organic compounds in a polymethylmethacrylate matrix pumped by a copper vapor laser are studied. The results demonstrate that the transverse pumping scheme of solid-state laser-active media with the copper vapor laser is promising compared to the longitudinal pumping scheme from the viewpoint of the lifetime parameters. Received: 6 February 2002 / Published online: 2 May 2002     

Asymptotic Characteristics of the Evolution of Polarization of Nonmonochromatic Radiation in Single-Mode Optical Fibers with Random Twisting of Axes of Linear Birefringence. II. The Asymptotic Behavior of the Degree of Polarization at Large Fiber Lengths

In this paper, we determine the asymptotic behavior for the squared degree of polarization of nonmonochromatic radiation propagating in a large-length fiber with random irregularities. It is found that the average squared degree of polarization tends to zero with the fiber length as the inverse square root of the fiber length.     

A generalization of the classical moment problem on *-algebras with applications to relativistic quantum theory. II

We discuss some properties of a non-commutative generalization of the classical moment problem (them-problem) previously introduced. It is shown that there is a connexion between the determination of the problem and the self-adjointness properties in the corresponding Hilbert space. This generalizes the well-known connexion between the determination of the measure in the classical moment problem and the self-adjointness properties of the polynomials as operators in the correspondingL ²-space. The dependence of them-problem on the choice ofC*-semi-norms and on the action of *-homomorphisms is also investigated. As an application, it is shown that if a quantum field (in a very general sense) is essentially self-adjoint then them-problem for the Wightman functional is determined on the quasi-localizableC*-algebra and that the corresponding representation of the localizable algebra generates the bounded observables of the field. It is pointed out that (ultraviolet and spatially) cut-off fields fall in this class and, therefore, are in one to one correspondance with states on the quasi-localizableC*-algebra.Laboratoire associé au Centre National de la Recherche Scientifique.     

A new class of holographic materials based on semiconductor CdF2 crystals with bistable centers. Part II. Growth of optically perfect crystals

The crystal-chemical processes occurring during the growth of cadmium fluoride crystals doped with bistable gallium and indium impurities and during conversion of the crystals to the semiconductor state are considered. It is found that doping with indium does not strongly affect the optical performance of the crystals, while gallium, due to its low solubility in cadmium fluoride, strongly impairs this performance. It is shown that co-doping of the crystals with highly soluble impurities (yttrium, scandium, and gadolinium fluorides) makes it possible to obtain optically perfect gallium-doped crystals.     

Detailed study of the cluster structure of light nuclei in a three-body model: (II). The spectrum of low-lying states of nuclei with A = 6

The three-body α + 2N model developed in our earlier works to describe the ground states of the A = 6 nuclei is generalized here to describe the spectrum of the low-lying states of these nuclei. The levels of the nuclei are shown to be differently sensitive to the various Nα interaction components, whence some conclusions concerning the true form of the Nα interaction are drawn. The geometric structure of the ⁶Li and ⁶He ground states is studied in detail. A significant contribution of the stretched cigar-shaped three-particle configuration NαN with an α-particle between two nucleons has been found. The wave functions of the ground and excited states of the A = 6 nuclei are tabulated. The wave functions found have been tested carefully using numerous experimental data.     

A dislocation dynamics study of the strength of stacking fault tetrahedra. Part II: interactions with mixed and edge dislocations

In this paper we present the sequel to Part I and present a comprehensive dislocation dynamics study of the strength of stacking fault tetrahedra to mixed and edge dislocation glides in fcc Cu.     

Anomalies of Radiation Absorption and Superluminal Propagation of light: II. A Layer of a Periodic Medium with a Helical Structure

The features of superluminal propagation of light through a layer of a helical periodic medium (HPM) are investigated and the group velocity is calculated. Multilayer systems with a layer of an HPM that provide superluminal propagation of light over large distances with compensation of losses upon light transmission through the system are considered. The features of radiation absorption in a layer of an HPM are considered. Effects of anomalously high and anomalously low absorption are found. It is shown that these effects are caused by an increase (decrease) in the density of light energy in the layer and by changes in the group velocity. The possibility of experimental observation of the effects discovered is discussed.     

A continuum model of a solid with a free surface: II. Considerations of application of the model to particle-surface interaction theory

Considerations of application of a continuum model of a solid with a free surface to particle-surface interaction theory are presented. The work is based on the recent normal-mode analysis of such a model by the author. It is shown that the model has some important unrealistic properties which do not occur in discrete-lattice models, and it is concluded that considerable care is needed in interpreting some of the predictions of the model, particularly with regard to the importance of normal modes of the non-bulk type, for example surface modes.     

具有流动和侧向Helmholtz共振器的驻波管内声场研究Ⅱ.实验验证及结果讨论

利用建立的具有流动和侧向Helmholtz共振器的驻波管的实验装置,成功地证实了作者所作的理论分析,包括有流动驻波管和Helmholtz共振器连接处的间断条件、驻波管末端的反射条件、切向流时Helmholtz共振器声阻抗,并实验确定了末端修正系数和等效半径系数。接着,应用理论分析和实验得到的结果讨论了流动对Helmholtz共振器性能和驻波管声场的影响,结果表明,流动会降低一些消声效果,但在具有流动的驻波管中采用Helmholtz共振器仍然是一种降噪的有效方法。     

A System of Partial Differential Equations with High-Frequency Coefficients and Stokes Operator in the Main Part. Asymptotic Integration in the Case of Multiple Degeneration

The problem of time-periodic solutions is considered for a system of partial differential equations with the Stokes operator in the main part with coefficients rapidly oscillating by time in the case of multiple degeneration of the averaged stationary operator. The results concerning the existence and uniqueness of these solutions are proved and their asymptotic expansions are constructed and justified.