A study of the photoluminescence of crystals of the hexagonal modification of Β-Ga2As3

The excitation and radiation spectra of-Ga₂As₃ crystals have been studied. The radiation spectrum consists of two overlapping bands (1.44 and 1.61 eV) and a very weak band in the 2.8–2.9 eV region. The temperature dependence of the halfwidth of the luminescence bands was studied and the position of the levels responsible for the luminescence were determined: E_1,v = 0.84 eV and E_2,v = 0.59 eV. These luminescence bands in -Ga₂As₃ crystals undergo thermal quenching. The kinetics of the photoconductivity and the photoluminescence were studied and it was shown that the recombination of nonequilibrium carriers occurs by two channels: via fast s levels and slow r levels, the trapping cross section of the latter being .Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 72–75, September, 1972.     

On algorithms for and computing with the tensor ring decomposition

Tensor decompositions such as the canonical format and the tensor train format have been widely utilized to reduce storage costs and operational complexities for high‐dimensional data, achieving linear scaling with the input dimension instead of exponential scaling. In this paper, we investigate even lower storage‐cost representations in the tensor ring format, which is an extension of the tensor train format with variable end‐ranks. Firstly, we introduce two algorithms for converting a tensor in full format to tensor ring format with low storage cost. Secondly, we detail a rounding operation for tensor rings and show how this requires new definitions of common linear algebra operations in the format to obtain storage‐cost savings. Lastly, we introduce algorithms for transforming the graph structure of graph‐based tensor formats, with orders of magnitude lower complexity than existing literature. The efficiency of all algorithms is demonstrated on a number of numerical examples, and in certain cases, we demonstrate significantly higher compression ratios when compared to previous approaches to using the tensor ring format.     

Assessing the subsequent effect of nitrogen released from tobacco-waste on maize crop using a 15N isotope technique

The investigation of the residual effect of nitrogen (N) released from tobacco-waste (TW) using isotope techniques will provide valuable data for sustainable organic farming. For this aim, a pot experiment was conducted using the ¹⁵N isotope technique. The experiment was based on a completely randomised design with four replications and was conducted on a calcareous ustochrepts soil. TW at levels of 0, 10, 20, 30 and 40 t ha^?1 and N fertiliser as (NH₄)₂SO₄ at levels of 0, 20, 40, 60 and 80 kg N ha^?1 were used for the Bezostaja-1 wheat variety. Concerning mineral N fertilisation with 20 and 80 kg N ha^?1, additional treatments with ¹⁵N-labelled (NH₄)₂SO₂ (10 at.% exc.) have been applied. Following harvesting wheat plants, the Pioneer 3377 maize variety was used to see the residual effect of TW. After harvesting, dry matter yields were recorded and total N concentrations were determined. ¹⁵N determinations and calculations were also made for ¹⁵N treatments separately. TW had a significant residual effect on the growth of corn plant under the pot condition. Increasing rates of TW significantly increased the dry matter yield of corn plant following wheat from 3.31 t ha^?1 (at control) to 7.89 t ha^?1 (at the TW treatment of 40 t ha^?1). The ¹⁵N values derived from the ¹⁵N fertiliser decreased with increasing TW application. The average values of N derived from N fertiliser (Ndff) varied from 2.14 to 3.09% at the rates of 20 and 80 kg N ha^?1, respectively. However, N derived from TW (Ndftw) significantly increased from 16.93 to 24.59% (at 20 kg N ha^?1), and it also increased from 23.06 to 28.15% (at 80 kg N ha^?1) with increasing TW applications from 20 to 40 t ha^?1, respectively.     

Anti-hydroxyl radical activity,redox potential and anti-AChE activity of Amanita strobiliformis polysaccharide extract

This study outlines antioxidant and anti-AChE activities of the polysaccharide (PSH) extract from the mushroom species Amanita strobiliformis. Both the presence of α and ß glucans within the aforementioned extract was recorded. PSH extract displayed a profound scavenging activity of OH radicals (IC₅₀ value, 11.86 ± 0.59 μg/mL) and high potential for reduction of Fe³⁺ ions (174.11 ± 8.70 mg eq. AA/g d.w.) being almost 48- and 5-fold more effective than mannitol and butylated hydroxytoluene used as a positive control, respectively. Compared with galanthamine (0.001 μg), the same extract exhibited a moderate anti-AChE activity (10 μg) in solid. Since purified PSH extract exhibited higher bioactivity (IC₅₀ value 7.27 ± 0.31 μg/mL, 197.68 ± 9.47 mg eq. AA/g d.w. and 0.1 μg, respectively), it can be predominantly ascribed to the polysaccharide compounds. A. strobiliformis PSH extract may be considered as a promising resource of potent bioactive polysaccharides of natural origin successfully addressing both oxidative stress and lack of acetylcholine.     

Stability and electronic properties of IrnV (n = 2–10) nanoclusters and their reactivity toward N2H4 molecule

Structural Chemistry - DFT calculations have been carried out over the IrnV (n = 2–10) clusters in order to predict their stability, electronic, and catalytic properties. Based on the...     

Plasma Enhanced Chemical Vapor Deposition of Poly(Cyclohexyl Methacrylate) as a Sacrificial Thin Film

Plasma Chemistry and Plasma Processing - In this study, thin films of poly(cyclohexyl methacrylate) (PCHMA) were deposited on silicon wafer using PECVD technique, in which the plasma power is...     

Oil composition and some morphological characters of Crambe orientalis var. orientalis and Crambe tataria var. tataria from Turkey

Native Crambe orientalis var. orientalis and Crambe tataria var. tataria collected from Kahramanmaras flora were morphologically examined and seed oil composition was determined. Volatile acid and fatty acid composition of seeds were examined with GC and GC/MS and the ratio of volatile acids to total oil was 3.49% in C. orientalis and 17.49% in C. tataria. The ratio of fatty acids to total oil was 92.03 and 67.28% in C. orientalis, and C. Tataria, respectively. The amount of erucic acid was 39.29% in C. orientalis and 29.87% in C. tataria. High linolenic acid (21.21%) and linoleic acid (12.42%) was found in C. orientalis oil, and high linolenic acid (15.01%) and linoleic acid (9.00%) was also found in C. tataria oil.     

Orientational dependence of shape memory effects and superelasticity in CoNiGa,NiMnGa, CoNiAl,FeNiCoTi, and TiNi single crystals

The dependence of deforming stresses, shape memory effect (SME), and superelasticity (SE) on the orientation of the single crystal axis, test temperature, and disperse particle size is examined for CoNiGa, NiMnGa, CoNiAl, FeNiCoTi, and TiNi single crystals. The orientational dependence of SME, SE, and temperature interval of the development of martensitic transformations (MT) under loading and SE is established. The influence of disperse particles on magnitudes of SME, SE, and mechanical hysteresis is discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 4–20, September, 2004.