Preparation and Storage of Silver Nanoparticles in Aqueons Polymers

以水溶性聚合物为保护剂,采用化学还原法制备了银纳米粒子,分别利用透射电子显微镜、紫外可见光谱、同步光散射光谱等手段对其进行了表征,并探索了制备银纳米粒子的最佳实验条件。通过将银纳米粒子-聚合物溶液进行脱水,得到含有银纳米粒子的固态聚合物膜。将固态聚合物膜重新溶解于水,其水溶液的紫外可见光谱与脱水前的溶液进行了比较,发现两者性质并无明显差异。因此,将银纳米粒子分散固定在聚合物膜中是一种崭新而有效的银纳米粒子制备和存储方法。     

Anisotropy of Light Scattering by Foamed Liquids

Optics and Spectroscopy - Optical transport parameters (transport propagation length of radiation and scattering length) have been experimentally studied in samples of a foamed liquid for a...     

Thermal isomerization of 1,1,3-trimethyl-1-silacyclobutane in the gas phase

Russian Chemical Bulletin -     

Thermodynamic properties of thiosamarates of calcium and barium and phases based on them

Effect of the nature of the alkaline-earth metal on the electrolytic and thermodynamic properties intrinsic to ternary thiosamarates of barium and calcium, which are capable of forming sulfide-conductive solid electrolytes, is considered. The thermodynamic property are examined by resorting to various modifications of the EMF method in concentration circuits with transfer. Dependence of the activity of binary CaS, BaS, and Sm₂S₃ in ternary MeSm₂S₄ on the composition of solid solutions is investigated with simultaneous determination of cationic and anionic transport numbers. The tendency of variations in the partial molar dissolution enthalpy \(\Delta \bar H_{Sm_2 S_3 } \) in thiosamarates of alkaline-earth metals is studied as a function of the doping-additive content. The vacancy mechanism of the defect formation in the phases under investigation is confirmed. Thermodynamics of the formation of ternary BaSm₂S₄ out of binary sulfides is explored and \(\Delta H_{fBaSm_2 S_4 }^0 \) is determined for the first time ever.     

STUDY ON TARGET RESIDUES FROM THE INTERACTION OF COPPER WITH 44MeV/A12C IONS

Cross sections and average forward ranges were determined for 35 target residues from the interaction of copper with 44MeV/A¹²C ions with nuclear chemistry techniques.From these data the isobaric yield distribution,the mass yield distribution and the longitudinal momentum transfer were obtained.The mass yield distribution and the isobaric yield distribution are in good agreement with those calculated from a modified statistical model and corresponding Monte Carlo technique.     

STUDY OF πNN VERTEX FROM HADRON AND QUARK POINT OF VIEW

we have identified the first-order mixing amplitude of πNN process described by the hadron model with the second-order mixing amplitude of the same process described by the quark model.Then the expression for the coupling constant f_π of the πNN vertex with different quark wave functions and gluon propagators in different approximations has been derived. The calculation results of f_π have been compared with experimental data.     

Physical properties of n-CdGeAs2 single crystals prepared by low-temperature crystallization

The first results obtained in studies of the temperature dependences of electrical conductivity and Hall constant of n-CdGeAs₂ single crystals prepared by low-temperature crystallization are reported. It has been established that the method developed permits growing single crystals with a free-electron concentration ⋍(1−2)×10¹⁸ cm⁻³ and a Hall mobility ⋍10000 cm²/(Vs) at T=300 K. It is shown that the temperature dependence of Hall mobility exhibits a behavior characteristic of electron scattering by lattice vibrations, whereas below 150 K a deviation from this law is observed to occur evidencing an increasing contribution of static lattice defects to scattering. The Hall mobility in the crystals prepared was found to reach ⋍36000 cm²/(Vs) at 77 K. Photosensitive heterojunctions based on n-CdGeAs₂ single crystals were prepared. The spectral response of the photosensitivity of these structures is analyzed. It is concluded that this method is promising for preparation of perfect CdGeAs₂ crystals. Fiz. Tverd. Tela (St. Petersburg) 41, 1190–1193 (July 1999)     

Nuclear Liquid-Gas Phase Transition Shown in Multifragment ation

The Incomplete-Fusion-nagmentation Model has been used to reproduce nicely the experimental evidence of liquid-gas phase transition probed in the reaction of Au + Au at 600A MeV. The analysis of the relative yields of decay modes for the projectile remnant as a function of bound> shows clearly the competition and transformation processes of various decay modes of projectile remnant with decreasing of bound>. The agreement between theoretical and experimental results for the anaJysis of relative yield of decay modes indicates that the experimental evidence of liquid-gas phase transition is composed of the decay mode transformations.     

Strangeness production in pA and AA collisions at 158 A GeV

LUCIAE, a hadronic and string cascade model and its corresponding event generator are used to analyse strangeness production singly and multiply in p-Pb and Pb-Pb collisions at 158 A GeV. Spectra of multiplicity and transverse mass for single (Λ, Λ) and multiple (Ξ-, Ξ-, Ω-, Ω-) strangeness are given. In LUCIAE model it suggests a physical mechanism, i.e. the dependence of the strange quark suppression factor on incident energy, projectile mass and centrality of colliding system might result in increase of yield of strange particles with increasing the above three parameters. Calculations from the model reconstruct well the WA97 experimental data: increase of yield of strange particles with increasing centrality and increase of strangeness enhancement with increasing number of strange quarks, in relativistic nucleus-nucleus collisions.