Nitroguanyl azide

Crystals of the title compound, nitro­carbam­imidoyl azide, CH₂N₆O₂, consist of two symmetry‐independent mol­ecules and the structure is stabilized by intra‐ and intermolecular hydrogen bonds. The mol­ecule possesses a nitr­imine structure.     

QCD PERTURBATION THEORY AND NUCLEI (1) THE ENERGY SHIFTS OF HADRENS AND HADRONS MASS DIFFERENCE MASS DIFFERENCE

QCD perturbation theory for confined quarks and gluons (inhadrons) is discussed.Based on the equivalent potential for the quark-gluon interaction derived, the energyshifts of hadrons and hadron mass difference in MIT bag (cavity) model and correcpond-ing approximation of the w. f. with Gassian form are calculated.     

Theoretical Investigations of Nonlinear Optical Properties of Transition Metal Cluster Anions

In the framework of density functional theory （DFT）, the electronic excitations and nonlinear optical （NLO） properties of six binuclear transition metal cluster anions with the formula of [Ch2M-（μ-Ch）2-M＇CN]^2- （M = Mo, W; Ch = S, Se; M＇ = Cu, Ag） have been systemically investigated at both cases of gas phase and DMF solution. The obtained electronic absorption spectra reveal that the element replacements of metals M and ligands Ch have significant influence on the absorptions, especially on the low-lying ones. In addition, the transitions of μ-Ch→M are dominant for the low-lying excitations, whereas the transitions of M＇→M as well as Ch→M are mainly responsible for the higher excitations. The calculated molecular first and second hyperpolarizabilities present the remarkable element substitution and solvent effects. The analyses show that the transitions involving μ-Ch→M charge transfer make the critical contributions to the first hyperpolarizability t, and that the charge transfers from the moieties of MCh4 to M＇CN as well as those of μ-Ch→M and M＇→M are responsible for the second hyperpolarizability y. Moreover, the introduction of solvent leads to the results that the transitions within the moieties of MCh4 and M＇CN make larger contributions to the hyperpolarizability, especially to γ.     

Λ Production and Λ/p Ratio in Relativistic Heavy Ion Collisions

The Λ multiplicity and Λ/p ratio are studied by hadron transportation-string fragmentation model in relativistic heavy ion collisions. Firstly, the dependence of Λ multiplicity and Λ/p ratio on the system size and the collision centrality is studied. It shows that the Λ and p multiplicities go up as the increase of system size and the increase of collision centrality. However, their ratio keeps almost a constant. The effect of Λ annihilation cross section to Λ multiplicity and Λ/p ratio is also studied. It is found that this effect is weak: Λ multiplicity and Λ/p ratio have a little amount of increase by the decrease of Λ annihilation cross section. Even the cross section is down to zero, Λ/p ratio is only 1.2 in 200A GeV AuAu head on collision. The Λ/p ratio is obtained to be 0.28 in pp collision, lying in the range of experimental data:0.2—0.3. It is also obtained that the ratio in AA collisions is 3—5 times of that in pp collision.     

Analyzing powers in the 12C( \vec d ,p)13C reaction at the energy T d = 270 MeV

The preliminary results on the tensor T₂₀ analyzing power for the ¹²C(,p)¹³C* reaction with the excitation of ¹³C levels and the d(,p)X reaction at the energies T _d = 140, 200 and 270 MeV at the emission angle Θ _cm = 0° are presented. The data on the tensor A _yy and vector A _y analyzing powers for the ¹²C(,p)¹³C* reaction at the energy T _d = 270 MeV in the angular range from 4° to 18° in the laboratory are also obtained.     

Hydration of Bromine Ions in Water

A mass spectrographic method electrospraying electrolyte solutions in vacuum was used to determine the enthalpy of hydration of bromine ions by different numbers of water molecules. The mass spectra of negative ions from aqueous solutions of NaBr were measured over the temperature range of 15–50°C and showed that the most intense peaks correspond to the hydrated bromine ions with one and two water molecules. It was found that the Van't Hoff equation holds for bromine hydrates containing up to three water molecules, whereas addition of the fourth water molecule leads to a violation of the Van't Hoff equation. The enthalpy of bromine ion hydration by the first and the second water molecules was found to be –(28.5 ± 1.7) and –(21 ± 4.2) kJ/mol, respectively.     

Thermal deformations of a glass spherical satellite

The effect of the kind of the reflecting coating of a glass spherical satellite on thermal deformations caused by the solar irradiation is considered. Two types of coating deposited on one of the hemispheres are considered: aluminum with a protective layer of bakelite varnish and interference dielectric coating for two orientations of the satellite orbit. Structures of a multilayer dielectric coating and technologies of its deposition are described.     

Optimization of the crystallization rate in growing Bi4Ge3O12 crystals by the LTG CZ technique

The influence of the growth rate on the shaping and quality of Bi₄Ge₃O₁₂ (BGO) crystals during their growth by the low-thermal-gradient Czochralski technique has been studied. Several series of BGO crystals have been grown with the rate varying from 0.3 to 15 mm/h. The limited growing rates at which the crystal quality is not deteriorated are established. The results of the study make it possible to increase the growth rate in commercial systems by a factor of 1.5–2 and thus significantly increase the growth efficiency.