Formation of expanded smooth quasi-Bessel beam range due to the transformation of the Gaussian beam in absorbing axicon

The quasi-Bessel beam range produced by an absorbing axicon is investigated. It is shown that when an incident Gaussian beam is used, the absorbing axicon stretches (with respect to transparent axicon case) the uniform on-axis light intensity distribution length, as well as expanding the quasi-Bessel beam range. In addition, the peak of axial light distribution is shifted from the axicon tip. As a result any spatial modulation formed due to the bluntness of the tip is reduced close to the on-axis intensity peak, which becomes more smooth and uniform.     

Synthesis of 2,4-substituted 3-oxo-1-phenylcyclopentane-1-carboxylic acids

A procedure has been developed for the synthesis of 2,4-substituted 3-oxo-1-phenylcyclopentan-1-carboxylic acids, and substituent effects on particular steps of the synthesis have been studied.     

Isoquinoline derivatives VI. Synthesis and pharmacological properties of 4,6,7-substituted 1(2)-arylalkyl-1,2,3,4-tetrahydroisoquinolines and their analogs

The condensation of 6,7-dimethoxy-1,2.3.4-tetrahydroisoquinoline (II) with diphenylacetyl and diphenylpropionyl chlorides gave the corresponding amides (III). Reduction of III with lithium aluminum hydride converted them to tertiary amines IV, which were characterized as their hydrochlorides. The condensation of equimolecular amounts of amines I with the acid chlorides of substituted phenylacetic and diphenylpropionic acids gave amides V. The reduction of amides V with lithium aluminum hydride gave secondary amines VI. The corresponding tetrahydroisoquinolines (VII) were obtained by the cyclization of amides V and subsequent reduction with lithium aluminum hydride, The condensation of 1-diphenylethyl-6,7-dimethoxy-l,2,3,4-tetrahydroisoquinoline with formalin gave VIII. The IR spectra of the synthesized compounds were examined. The effect of these compounds on the arterial blood pressure and the coronary blood flow was studied.See [1] for communication V.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1683–1687, December, 1971.     

Synthesis of Ethyl cis- and trans-4-Chloro-5-oxo-1,2-diphenylpyrrolidine-2-carboxylate

Ethyl cis- and trans-4-chloro-5-oxo-1,2-diphenylpyrrolidine-2-carboxylate have been synthesized by the cyclization of ethyl N-(,-dichloropropionyl)-N-phenyl--aminophenylacetate.     

Fe2O3 transformation to iron chlorides in radical chain gas-phase chlorination of methane

It has been established that the formation of iron chlorides in chain gas-phase reaction of methane chlorination is observed starting with T650 K. At Cl₂:CH₄=4:1, Fe₂O₃ is transformed to FeCl₃. With increasing methane concentration (Cl₂:CH₄=1:1), besides FeCl₃, FeCl₂ is also formed. Kinetic regularities of the reaction have been studied at 600–1200 for both gaseous mixtures.

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, 650 . : 41, Fe₂O₃ FeCl₃. (Cl₂CH₄=11) , FeCl₃ FeCl₂. 600–1200 -.

     

Asymptotical analysis of negative insurance premiums in critical situations

The paper considers the risks of the insurance companies that conduct purely rent operations. The asymptotic of certain distribution functions are found in the case of a heavy traffic and regular tail variation of the premium distribution function.     

Investigation of the Circular Waveguide Radiating Slotted Structures Using Polarization Degeneration of the Main Mode Wave

The unusual paired slotted radiating structure of a circular waveguide is investigated when the wave of main mode H₁₁ is propagating in it. This structure is constructed in such a way that the phenomenon of the polarization degeneration of wave with this mode is taken into account. In the waveguide cross-section, the centers of the paired half-wave transverse slots are spaced by an angle γ over both sides of the waveguide diametric line along the direction of polarization of the H₁₁ mode. The radiation patterns at different spaced angles γ equal to 45°, 65°, and 72° as well as at the two-tiered location of such paired slots are investigated. The second tier is located on the distance equal to the half of the waveguide wavelength along the waveguide longitudinal axis. The pair slots of both tiers have the same γ angle but they are located at the opposite sides of the waveguide. The possibility is shown of synthesizing an omnidirectional radiation pattern by combination of the two-tiered structure with the opposite frontal slots and the two-tiered structure with the oppositely paired slots.