Henan University of Technology

About: Henan University of Technology is a education organization based out in Zhengzhou, China. It is known for research contribution in the topics: Catalysis & Chemistry. The organization has 7648 authors who have published 6503 publications receiving 73067 citations. The organization is also known as: Hénán Gōngyè Dàxué.

Structural characterization and antioxidant activity of polysaccharides extracted from jujube using subcritical water

Abstract: Polysaccharides were extracted from jujube fruit using an efficient, optimized subcritical water extraction process. A maximum crude polysaccharide yield of 7.9% was obtained at an extraction temperature of 140 °C and a time of 60 min. The crude polysaccharides extracted under these conditions were purified. Three polysaccharide fractions, ZP1, ZP2 and ZP3, were obtained and their structures were investigated. The three fractions were mainly composed of arabinose, galactose, glucose, mannose, rhamnose, and galacturonic acid. ZP3 was further investigated using methylation and NMR spectroscopy, and ZP3 comprised a main chain of (1 → 4)-α-D-GalAp, (1 → 2,4)-α-L-Rhap, with a (1 → 4,6)-α-D-Galp branch. Assays of antioxidant activity showed that ZP3 exhibited a remarkable DPPH capacity and moderate hydroxyl radical scavenging ability, suggesting that it has potential applications as a natural antioxidant in foods and pharmaceuticals.

Mechanically Tough, Thermally Rearranged (TR) Random/Block Poly(benzoxazole-co-imide) Gas Separation Membranes

Abstract: Insufficient mechanical properties are one of the major obstacles for the commercialization of ultrahigh permeability thermally rearranged (TR) membranes in large-scale gas separation applications. The incorporation of preformed benzoxazole/benzimidazole units into o-hydroxy copolyimide precursors, which themselves subsequently thermally rearrange to form additional benzoxazole units, were prepared for the first time. Using commercially available monomers, mechanically tough membranes prepared from random and block TR poly(benzoxazole-co-imide) copolymers (TR-PBOI) were investigated for gas separation. The effects of the chemical structures, copolymerization modes, and thermal holding time of o-hydroxy copolyimides on the molecular packing and properties, including gas transport, for the resulting TR-PBOI membranes have been examined in detail. After treatment at 400 °C, tough TR-PBOI membranes exhibited tensile strengths of 71.4–113.9 MPa and elongation at break of 5.1–16.1%. Moreover, they presented hig...

On the ruin probabilities of a bidimensional perturbed risk model

Abstract: We follow some recent works to study the ruin probabilities of a bidimensional perturbed insurance risk model. For the case of light-tailed claims, using the martingale technique we obtain for the infinite-time ruin probability a Lundberg-type upper bound, which captures certain information of dependence between the two marginal surplus processes. For the case of heavy-tailed claims, we derive for the finite-time ruin probability an explicit asymptotic estimate.