[(C~8H~8)Y(μ-OC~6H~5)(THF)]~2的合成和晶体结构

本文用(C~8H~8)Y(μ-Cl)(THF)]~2与NaOC~6H~5以1:2摩尔比在四氢呋喃中反应, 合成了新的中性配合物[(C~8H~8)Y(μ-OC~6H~5)(THF)]~2, 经过分离, 在-30℃下培养得到无色晶体, 用元素分析, 核磁共振和质谱进行了鉴定, 并以X-射线衍射测定了晶体结构。     

An efficient synthesis of new polyfunctional hexahydro pyrido[1,2-a]pyrazin-1-ones

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New nanomolar negative modulators of AMPA receptors

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Regularities of adhesive failure in particulate filled polymers

The effect of adhesion between matrix and filler on mechanical properties of composites is analyzed. It is shown, that the loss of adhesion (extension of exfoliated surface) leads to a marked reduction of uniaxial tension modulus. Regularities of interphase crack growth were found and dependences of initial (critical) and final angles of exfoliation upon mechanical and scale factors were obtained.     

Conformationally controlled intramolecular heterocyclization of 2,4-diaminoperfluoro-4-methyl-2-pentenethiocyanate-3

Perfluoro-2-methyl-2-pentene-thiocyanate-3 reacts with ammonia to give 2,4-diaminoperfluoro-4-methyl-2-pentenethiocyanate-3 ( 4 ) and 2-aminoperfluoro-4, 4-dimethyl-4,5-dihydro-5-ethylidene-1,3-thiazole ( 5 ). Compound 4 is kinetically stable and at 150°C under-goes rotational isomerization to afford the cyclic isomer 2-amino-4,4-bis(trifluoromethyl)-4,5-dihydro-5-(1-aminoperfluoroethylidene) -1,3-thiazole ( 6 ). Intramolecular cyclizations, resulting in the thiazolines 5 and 6 , proceed likewise via the Thorpe reaction. For compounds 4–6 , X-ray diffraction analyses were undertaken and IR spectra in solution and in solid state were investigated. It is supposed that a high kinetic preference for formation of 4 and the fact that it does not undergo spontaneous cyclization in ammonolysis stem from the NH …︁ N intramolecular hydrogen bonding between two amino groups.     

Giant lamb shift in photonic crystals

We obtain a general result for the Lamb shift of excited states of multilevel atoms in inhomogeneous electromagnetic structures and apply it to study atomic hydrogen in inverse-opal photonic crystals. We find that the photonic-crystal environment can lead to very large values of the Lamb shift, as compared to the case of vacuum. We also suggest that the position-dependent Lamb shift should extend from a single level to a miniband for an assembly of atoms with random distribution in space, similar to the velocity-dependent Doppler effect in atomic/molecular gases.     

Effect of polymers with a conjugation system on the mechanical properties of phenol-formaldehyde resite

Certain mechanical properties of a phenol — formaldehyde resin of the novolac type cured with hexa methylenetetramine in the presence of PCB have been investigated. The curves representing the dependence of the flexural strength, impact strength, and hardness of the specimens on PCB concentration are extremal in character. It is shown by electron microscope techniques combined with oxygen etching of the cleavage surface that the improvement in mechanical properties is associated with a change in the structure of the crosslinked polymer.Communication 108 of the series "Polymers with a conjugation system."Institute of Chemical Physics, AS USSR, Moscow. Translated from Mekhanika Polimerov, Vol. 4, No. 6, pp. 1071–1076, November–December, 1968.     

Simple Interpretation of Kinetics of Fast Solid-State Reactions

A simple model of fast solid-state reaction of two substances on the phase boundary is proposed. It is assumed that the reaction is controlled by the formation of new surface. The dependence of a change in the surface on the value of shear deformation is calculated. Thus, the relation between the product yield and shear deformation independently of time is explained.     

Apodization‐Assisted Subdiffraction Near‐Field Localization in 2D Phase Diffraction Grating

Conventional phase diffraction gratings can be used to localize the incoming optical radiation in the near‐field region. A new design of the binary phase diffraction grating is proposed with embedded pupil opaque mask inside each stripe. By means of numerical simulations, it is shown that with this masked phase grating the spatial resolution of the near‐field localization can be substantially improved and brought even beyond the solid immersion limit (λ/2n). Moreover, due to anomalous apodization effect, the subdiffraction field localization is accompanied by intensity enhancement as compared to the non‐masked design. The pupil mask rearranges the optical fluxes within the stripes and promotes the Fano resonances excitation in the periodic step lattice. This can be important for advancing the phase grating‐based super‐resolution technologies, including subdiffraction imaging, interferometry, and surface fabrication.     

Towards experiments with highly charged ions at HESR

The atomic physics collaboration SPARC is a part of the APPA pillar at the future Facility for Antiproton and Ion Research. It aims at atomic-physics research across virtually the full range of atomic matter. An emphasis of this contribution are the atomic physics experiments addressing the collision dynamics in strong electro-magnetic fields as well as the fundamental interactions between electrons and heavy nuclei at the HESR. Here we give a short overview about the central instruments for SPARC experiments at this storage ring.