Zhejiang Gongshang University

About: Zhejiang Gongshang University is a education organization based out in Hangzhou, China. It is known for research contribution in the topics: Adsorption & Supply chain. The organization has 8258 authors who have published 7670 publications receiving 90296 citations. The organization is also known as: Zhèjiāng Gōngshāng Dàxué.

Multilayered vitamin C nanoliposomes by self-assembly of alginate and chitosan: Long-term stability and feasibility application in mandarin juice

Abstract: A polyelectrolyte delivery system for vitamin C, achieved by sequential deposition of positive chitosan (CH) and negative sodium alginate (AL) onto the surface of anionic nanoliposomes (NLs), was investigated. Compared with uncoated NLs, AL and CH coated NLs (AL CH NLs) displayed more significant changes in average diameter, zeta potential, pH and morphology, with lower lipid peroxidation and vitamin C release after 90 days of storage at 4 °C, suggesting that the shell (AL-CH) altered the surface properties of AL CH NLs and protected the core (NLs) structure from oxidation and hydrolysis. Further food matrices protection studies implied that mandarin juice fortified with AL CH NLs had less changes in organoleptic characteristics (pH, total acidity and color difference) and showed higher microbiological stability than naked NLs and vitamin C solution. Present results indicated that the biopolymers played a key role on the liposomal membrane structure stability and sustained release of entrapped molecules by a steric barrier on the surface. It provided a potential platform for tailored design of carriers for nutrients or preservatives to enhance both the shelf-life and safety of food matrices.

Removal of cadmium and lead from aqueous solutions using nitrilotriacetic acid anhydride modified ligno-cellulosic material

Abstract: Cadmium (Cd2+) and lead (Pb2+) posed severe health risks worldwide. To remove these contaminants from aqueous solution, a nitrilotriacetic acid anhydride (NTAA) modified ligno-cellulosic material (NTAA-LCM) was prepared and characterized. Batch sorption experiments were performed to evaluate the influences of various factors such as contact time, pH, ionic strength, temperature and initial metal concentration on the sorption of metals. Results from elemental analysis and FTIR suggested that ester bonds and amine groups were successfully introduced into NTAA-LCM. Fast adsorption rates were observed, and the maximum sorption capacities of NTAA-LCM for Cd2+ and Pb2+ reached 143.4 and 303.5 mg g−1 at 298 K, respectively. Both the pseudo-second-order model and the Langmuir model described the adsorption extremely well. Thermodynamic analysis showed that the sorption was endothermic but spontaneous. The sorption was a chemical process involving surface chelation and ion exchange; this was reflected in the metal/NTA ratio. Additionally, NTAA-LCM retained high metal sorption capacity after seven cycles of regeneration by HNO3.

Distributed resource allocation for D2D communication underlaying cellular networks

Abstract: In the paper, the distributed joint spectrum sharing and power allocation scheme is proposed to improve the local services in the Device-to-Device (D2D) communication underlaying cellular networks (CNs) with limited signaling overhead. The scheme aims to optimize the throughput of D2D communications over the shared uplink frequency spectrum meanwhile the base station (BS) protects the cellular users (CUs) from the interference of D2D users. Stackelberg game (SG) is formulated to model the problem for deriving the distributed scheme. In the game, the BS, as a leader, coordinates the interference from the D2D users to the cellular uplinks and maximizes its own profit by pricing the interference. On the other hand, D2D pairs, as followers, compete for the spectrum as a Nash non-cooperative game to maximize their own data rates individually. The pricing mechanism at the BS converging to the Stackelberg Equilibrium is studied. Finally, numerical examples are presented to verify the proposed scheme. It is shown that the scheme is effective on the resource allocation and the CU protection with limited signaling overhead.