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[en] MO LCAO method was used to calculate the electronic spectrum of impurity atoms, localized in Van der Waals' gaps of layered crystals of cadmium iodide. Dependence of energy position of impurity states on atom nature, surrounding, number of occupied vacancies within one lattice cell was investigated. The calculation data correspond with measured optical spectra of CdI2 crystals, intercalated by Cd, Ag, Au, Cu and Pb atoms. 7 refs
[en] Atomic force microscopy studies of the dynamics of the nanostructure formation on a van der Waals surface of CdI_2 crystals during aging in air environment under near-equilibrium thermodynamic conditions have been carried out. The nanostructure growth process is found to consist of three stages. At the first stage, there appear nano-sized pores due to the lattice dissolution at the outcrops of screw dislocations or other structural defects. At the second stage, the cone-shaped nano-clusters arise and grow in those nano-sized pores. At the third stage, the nano-clusters coagulate. The growth kinetics of coneshaped nano-clusters is described by a diffusion model based on the interdiffusion approximation for the components. The growth rate of nano-clusters is shown to depend on the time evolution of the concentration gradient of Cd"2"+ ions in the near-reaction zone
[en] The original version of this article unfortunately contains errors in Abstract, Section 4.4 Vickers microhardness test and Section 5 Conclusion. In Abstract (7th line) the word “hard” should be changed to “soft”, in Section 4.4 Vickers microhardness test, 15th line the value 1.04 should be changed to 3.27 and in the same sentence the word “hard” should be changed to “soft”. In Section 5 Conclusion (18th line) the word “hard” should be changed to “soft”.
[en] The invention relates to the radio electric engineering and can be used for fabrication of photodetectors and optoelectronic devices on base thereof. Summary of the invention consists of the fact that in the process for obtaining thin film heterostructure on base of the A2B6 compound including vacuum deposition of layers in the presence of a temperature gradient between the evaporator and substrate,firstly, it is deposited a narrow-band component layer, it is sensitised with saturated aqueous cadmium chloride solution, it is fired and etched, then it is deposited a wide-band component layer/ The technical result consists of increasing the amount of charge carriers at the expense of the narrow-band component layer alloying
[en] Based on theoretical and experimental observations, it has been established that the polytypes 2H and 4H act as basic structural units as regard to the formation of CdI2 polytypes. As a result of this, some general rules have been formulated which help understand (i) the nature of restrictions in the close-packed arrangements and to deduce the genuine CdI2 polytypes, and (ii) the classification of CdI2 polytypes into various possible groups. This further helps to conclude that (i) the CdI2 polytypes are simply a consequence of restrictions in the close-packed arrangements, (ii) the concept of stacking fault is superfluous as far as the formation of ordered polytypes are concerned, and (iii) the identification of CdI2 polytypes on the basis of intensity data has limited implications unless some practical use of polytypes are found. (author)
[en] The National Research Council has outlined the need for non-mammalian toxicological models to test the potential health effects of a large number of chemicals while also reducing the use of traditional animal models. The nematode Caenorhabditis elegans is an attractive alternative model because of its well-characterized and evolutionarily conserved biology, low cost, and ability to be used in high-throughput screening. A high-throughput method is described for quantifying the reproductive capacity of C. elegans exposed to chemicals for 48 h from the last larval stage (L4) to adulthood using a COPAS Biosort. Initially, the effects of exposure conditions that could influence reproduction were defined. Concentrations of DMSO vehicle ≤ 1% did not affect reproduction. Previous studies indicated that C. elegans may be influenced by exposure to low pH conditions. At pHs greater than 4.5, C. elegans reproduction was not affected; however below this pH there was a significant decrease in the number of offspring. Cadmium chloride was chosen as a model toxicant to verify that automated measurements were comparable to those of traditional observational studies. EC50 values for cadmium for automated measurements (176-192 μM) were comparable to those previously reported for a 72-h exposure using manual counting (151 μM). The toxicity of seven test toxicants on C. elegans reproduction was highly correlative with rodent lethality suggesting that this assay may be useful in predicting the potential toxicity of chemicals in other organisms.
[en] Existing polytype notations have been critically examined to select a single notation which can describe the CdI2 structures completely and most conveniently. A comparative study shows that the Zhdanov notation fulfils both the conditions. However, the ambiguities in the similar looking symbols is removed by employing some simple criteria proposed by Jain and Trigunayat for deciding the equivalent structures. Further, being numerical in nature this is the easiest notation to handle. (author)
[en] Lattice relaxation accompanying phototransformation of In bistable centers from the ground, deep state to shallow state in CdF2 crystal has been measured with the use of scanning tunneling microscope. It is shown that relatively small macroscopic changes of the crystal length in the order of 1.8 x 10-6 accompany the phototransformation of In ions. Lattice expansion upon the influence of population of shallow levels in CdF2 explains the observed small changes of lattice constant during the process. (author)
[en] A method for preparation of cadmium chloride hydrate including treatment of cadmium oxide with hydrochloric acid, filtration of the prepared solution, its evaporation and hydration of the product carried out simultaneously under 10-150 mm Hg at boiling temperature is proposed. The proposed method permits to increase the product quality, provide homo=. geneity of its phase composition (CdCl2x2.5H2O required content) and increase labour productivity