Evgrni $$\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l}$$ Invievich Givargizov (On the occasion of his 70th birthday)

Jubilees

Evgrni $\overset{\lower0.5em\hbox{$\overset{\lower0.5em\hbox{ Invievich Givargizov (On the occasion of his 70th birthday)     

Vladimir Mikha $$\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l} $$ lovich Fridkin (On the occasion of his 75th birthday)

Jubilees

Vladimir Mikha $\overset{\lower0.5em\hbox{$\overset{\lower0.5em\hbox{ lovich Fridkin (On the occasion of his 75th birthday)     

To the hundredth anniversary of Georgi\overset{\lower0.5em\hbox{ Glebovich Lemmlein

In Memorial

To the hundredth anniversary of Georgi $\overset{\lower0.5em\hbox{$\overset{\lower0.5em\hbox{ Glebovich Lemmlein     

Yuri\overset{\lower0.5em\hbox{ Andreevich Osipyan (On the occasion of his seventieth birthday)

Personalia

Yuri $\overset{\lower0.5em\hbox{$\overset{\lower0.5em\hbox{ Andreevich Osipyan (On the occasion of his seventieth birthday)     

Georgi $$\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l} $$ Borisovich Bokij (October 9, 1909–September 4, 2001)

Obituary

Georgi $\overset{\lower0.5em\hbox{$\overset{\lower0.5em\hbox{ Borisovich Bokij (October 9, 1909–September 4, 2001)     

Reaction of 2,3-bis(diphenylphosphino)maleic acid-thioanhydride (bmata) with PhCCo3(CO)9. X-ray diffraction structure of {\text{Co}}_{\text{3}} ({\text{CO)}}_{\text{6}} [\mu _2 ,\eta ^2 ,\eta ^1 {\text{ - C(Ph)}}{\text{(O)](}}\mu _2 {\text{ - PPh}}_{\text{2}} )

The benzylidyne-capped cluster PhCCo₃(CO)₉ (1) reacts with the diphosphine ligand 2,3-bis(diphenylphosphino)maleic acid-thioanhydride (bmata) to afford ultimately the new cluster ${\text{Co}}_{\text{3}} ({\text{CO)}}_{\text{6}} [\mu _2 ,\eta ^2 ,\eta ^1 {\text{ - C(Ph)}}{\text{(O)](}}\mu _2 {\text{ - PPh}}_{\text{2}} )$ (3) in low yield under thermolysis conditions or by Me₃NO activation of PhCCo₃(CO)₉. The intermediate cluster compound PhCCo₃(CO)₇(bmata) (2) has been confirmed by IR spectroscopy and is shown to give ${\text{Co}}_{\text{3}} ({\text{CO)}}_{\text{6}} [\mu _2 ,\eta ^2 ,\eta ^1 {\text{ - C(Ph)}}{\text{(O)](}}\mu _2 {\text{ - PPh}}_{\text{2}} )$ upon heating. Cluster 3 has been isolated and characterized in solution by IR and ³¹P NMR spectroscopies, and the solid-state structure of 3 was established by X-ray diffraction analysis. ${\text{Co}}_{\text{3}} ({\text{CO)}}_{\text{6}} [\mu _2 ,\eta ^2 ,\eta ^1 {\text{ - C(Ph)}}{\text{(O)](}}\mu _2 {\text{ - PPh}}_{\text{2}} )$ crystallizes in the triclinic space group P ${\bar 1}$ , a = 11.6053(8) Å, b = 11.8438(8) Å, c = 15.099(1) Å, α = 105.169(5)^○, β = 90.530(5)^○, γ = 104.976(6)^○, V = 1928.5(2) ų, Z = 2, and d _calc = 1.578; R = 0.0442, R _w = 0.481 for 2591 observed reflections with I > 3σ (I). The cyclic voltammetric properties of 3 have been investigated and are contrasted with the related bma-derived cluster ${\text{Co}}_{\text{3}} ({\text{CO)}}_{\text{6}} [\mu _2 ,\eta ^2 ,\eta ^1 {\text{ - }}{\text{(O)OC(O)](}}\mu _2 {\text{ - PPh}}_{\text{2}} )$ .     

On the problem of transient hydrodynamic instability of nematics in magnetic field: I. Instability at splay deformation

A dependence of the square of dimensionless magnetic-field (MF) strength on the square of dimensionless wave vector of the domain structure, $h^2 \left( {\tilde q^2 } \right)$ , is analytically derived for the transient hydrodynamic instability arising at splay deformation under a MF. The domain formation is related to the fold catastrophe; the square of the critical field of domain formation, h _D ² , is determined from the condition ${{\partial \left[ {h^2 \left( {\tilde q^2 } \right)} \right]} \mathord{\left/ {\vphantom {{\partial \left[ {h^2 \left( {\tilde q^2 } \right)} \right]} \partial }} \right. \kern-0em} \partial }\left( {\tilde q^2 } \right) = 0$ . In the general case, the function $h^2 \left( {\tilde q^2 } \right)$ is a ratio of two polynomials whose coefficients for calamitics are determined by combinations of four dimensionless viscosities ν₂/ν₁, ν₆/ν₁, ν₇/ν₁, and ν₈/ν₁. Under some assumptions, the quotient of the polynomials at large $\tilde q^2$ is a quadratic function which allows one to experimentally determine the dimensionless viscosities ν₂/ν₁, ν₆/ν₁, ν₇/ν₁, and α₂/ν₁.     

First-principles estimate of Peierls energy in sodium chloride

The Peierls barrier height for edge dislocations in sodium chloride crystal has been estimated from first principles based on the density functional theory. The calculation was performed using a plane-wave expansion of the Bloch functions of a periodic structure with sp. gr. Pmmm and a supercell containing an edge dislocation dipole of dominating slip system \({1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}\langle 110\rangle \{ \overline 1 10\} \). It is shown within the generalized gradient approximation for the exchange-correlation energy that, among the two symmetric positions of dislocation line in the Peierls relief, configuration I, which has a compact core of size d ≈ b (b is the Burgers vector length), is characterized by minimum energy. The second symmetric position corresponds to configuration II with an extended core (d ≈ 2b). Its energy exceeds the Peierls relief minimum by 1.2 × 10^–2 eV (per lattice period). An application of compressive stress changes the form of crystalline relief: its minimum moves to position II.     

On the reproducibility of the orientation distribution function of texture samples from pole figures (V). Discussion of the reprojection relationship

The exact solution of the problem \documentclass{article}\pagestyle{empty}\begin{document}$ \tilde P_{hi} (y) \to \tilde f(g) $\end{document} is discussed from the view of the structure of the reprojection relationship and its numerical realization.     

Program for calculating the scattering parameters used in the X-ray standing wave method

A computer program for calculating the complex kinematic scattering parameters χ₀, χ_h, and $\chi _{\bar h} $ of X rays, which are Fourier components of the crystal complex susceptibility, as well as some of their combinations, is presented. The values calculated by the program can be used for computer simulation of experimental results obtained by the X-ray standing-wave method. Methods for calculating these parameters on the basis of well-known tables are described in detail. For crystals of complex structure, it is necessary to know their structure and the Debye temperature or specific heat capacity in order to calculate χ_h and $\chi _{\bar h} $ . To calculate χ₀, it is sufficient to know the chemical formula and the density of a material.