Angular selectivity of liquid crystal composite gratings

Angular selectivity of volume phase transmission gratings formed in a liquid crystal composite for s-and p-polarized light is investigated in the absence of external electric field.     

Crystallisation of Wild-Type and Variant Forms of a Recombinant Plant Enzyme ��-d-Glucan Glucohydrolase from Barley (Hordeum vulgare L.) and Preliminary X-ray Analysis

Wild-type and variant crystals of a recombinant enzyme β-d-glucan glucohydrolase from barley (Hordeum vulgare L.) were obtained by macroseeding and cross-seeding with microcrystals obtained from native plant protein. Crystals grew to dimensions of up to 500 × 250 × 375 μm at 277 K in the hanging-drops by vapour-diffusion. Further, the conditions are described that yielded the wild-type crystals with dimensions of 80 × 40 × 60 μm by self-nucleation vapour-diffusion in sitting-drops at 281 K. The wild-type and recombinant crystals prepared by seeding techniques achived full size within 5–14 days, while the wild-type crystals grown by self-nucleation appeared after 30 days and reached their maximum size after another two months. Both the wild-type and recombinant variant crystals, the latter altered in the key catalytic and substrate-binding residues Glu220, Trp434 and Arg158/Glu161 belonged to the P4₃2₁2 tetragonal space group, i.e., the space group of the native microcrystals was retained in the newly grown recombinant crystals. The crystals diffracted beyond 1.57–1.95 Å and the cell dimensions were between a = b = 99.2–100.8 Å and c = 183.2–183.6 Å. With one molecule in the asymmetric unit, the calculated Matthews coefficients were between 3.4–3.5 ų·Da⁻¹ and the solvent contents varied between 63.4% and 64.5%. The macroseeding and cross-seeding techniques are advantageous, where a limited amount of variant proteins precludes screening of crystallisation conditions, or where variant proteins could not be crystallized.     

Basic features of a projected 50–60 Bev strong-focusing proton accelerator

The basic features of a projected 50–60 Bev strong-focusing proton accelerator are described. The critical energy is eliminated by changing the dependence of orbit length on momentum. The weight of the magnetic system, consisting of 120 sectors is less than 22,000 tons, the peak power is approximately 100,000 kva, the mean radius is 236 m.Reported to the All-Union Conference on the Physics of High-Energy Particles, May 14, 1956.     

Cadmium cathodic deposition on polycrystalline p-selenium: Dark and photoelectrochemical processes

Cathodic reduction of Cd²⁺ on p-Se proceeds at low overpotential in the dark and results in bulk Cd, while the underpotential deposition is kinetically inhibited. Cadmium adlayer is photoelectrochemically deposited on illuminated electrode 0.7 V above E(Cd²⁺/Cd). The adlayer cathodic deposition under illumination proceeds with simultaneous formation of CdSe nanoparticles. Potentiodynamic electrochemical impedance spectroscopy has discriminated the two products of the photoelectrochemical reaction both by their potentials of anodic oxidation and by characteristic dependences of impedance on potential. Anodic oxidation of CdSe nanoparticles gives a sharp peak of real impedance in low frequencies close to the corresponding anodic current peak in cyclic voltammogram. The impedance peak appears below a threshold frequency f_t. The latter separates two modes of diffusion in anodic dissolution of CdSe nanoparticles. The diffusion proceeds independently at different particles above f_t and turns to cooperative mode below the threshold frequency. Due to this effect, information on spatial distribution of growing nuclei on electrode surface in early stages of electrodeposition can be obtained from potentiodynamic impedance spectra.     

S. Vonsovsky and the Dawn of the Theory of Strongly Correlated Systems

Journal of Superconductivity and Novel Magnetism - A survey of scientific and social activity of S. V. Vonsovsky is presented. His fundamental works on the theory of electronic properties and...     

Electrical, photoelectrical, and photoelectrochemical properties of electrodeposited CdTe films subjected to high-energy irradiation

The general goal of this work is to study the structure and photoelectrical properties of the electrochemically deposited thin CdTe films. The conducted investigation has shown that (i) as-deposited films have the single-phase structure with a grain size of 1-10 μm and are of the n-type conductivity; (ii) photosensitivity abruptly decreases when the film thickness is over 10 μm; (iii) annealing at temperatures less than 500 °C improves the film quality with retention of the n-type conductivity; and (iv) photosensitivity of the films is not impaired under irradiation by 6 MeV electrons with a fluence of 5 × 10¹⁴ cm^− 2.