Showing papers by "Zhejiang Gongshang University published in 2022"

Efficient semiquantum key distribution based on single photons in both polarization and spatial-mode degrees of freedom

Abstract: In this paper, we propose an efficient semiquantum key distribution (SQKD) protocol which is based on single photons in both polarization and spatial-mode degrees of freedom. This protocol is feasible for a quantum communicant distributing a random private key to a classical communicant. This protocol need not require the classical communicant to use any quantum memory or unitary operation equipment. We validate the complete robustness of the transmissions of single photons between two communicants. It turns out that during these transmissions, if Eve wants not to be detected by two communicants, she will obtain nothing useful about the final shared key bits. Compared with Boyer et al.’s famous pioneering SQKD protocol (Phys Rev Lett 99:140501, 2007), this protocol has double quantum communication capacity, as one single photon with two degrees of freedom for generating the key bits can carry two private bits; and this protocol has higher quantum communication efficiency, as it consumes less qubits for establishing a private key of the same length. Compared with the only existing SQKD protocol with single photons in two degrees of freedom (Int J Theoret Phys 59:2807, 2020), this protocol has higher quantum communication efficiency.

Superhydrophobic PDMS@TiO2 wood for photocatalytic degradation and rapid oil-water separation

Abstract: Natural wood, with its unique porous structure, has been widely modified for separating oil-water mixtures. However, the separation efficiency is often unsatisfactory, and little attention is focused on mitigating secondary pollution after its usable lifespan. Here, a superhydrophobic material consisting of delignified wood coated with titanium dioxide (TiO2) and polydimethylsiloxane (PDMS) was prepared. The resulting [email protected]2 wood possessed outstanding superhydrophobicity, with a water contact angle of 160o. Owing to its longitudinal channels and excellent water repellency, the wood was successfully used to separate oil-water mixtures, with a high permeation flux of up to 6111 L·m−2·h−1 and separation efficiency of up to 93.4%. Importantly, PDMS and other oil pollutants were capable of being largely degraded after use via photocatalysis of the TiO2 layer, and the degradation reached 8.56 wt% within 30 days. The results from this study provide a method for fabricating functional superhydrophobic wood with photocatalytic degradation ability for efficient oily wastewater treatment.

Electrochemical nitrogen reduction: an intriguing but challenging quest

Abstract: The electrochemical nitrogen reduction (eNRR) offers a flexible and sustainable alternative to the well-established Haber–Bosch process to synthesize NH3 in a distributed and on-demand manner. Recent progress in the exploration of feasible eNRR systems has been impeded by inadequate understanding of eNRR mechanisms and plagued by interference from the unnoticed presence of reactive N-containing species. As a crucial requirement for the design of control experiments in eNRR research, the quantitative 15N2 experiment provides the direct and most reliable evidence of the eNRR process. Advanced in situ characterization techniques can deepen mechanistic understandings of the eNRR process, but attention should be devoted to the possible intervention of reactive nitrogen-containing species. Ammonia plays an indispensable role in global agroeconomics, chemical industries, energy carriers, and other diverse applications. To meet the demand for ammonia in these roles, the artificial synthesis of ammonia has traditionally relied on the well-established Haber–Bosch process that is commercially viable but energy intensive. Recently, the drive for sustainable alternatives has fueled interest in the development of electrochemical nitrogen reduction (eNRR) as a pathway for carbon-free ammonia synthesis. Nevertheless, research in the eNRR field remains elusive, partly because of the ominous presence of reactive nitrogen-containing species (Nr) and the lack of a thorough understanding of eNRR mechanistics. Herein, we provide an overview of efforts highlighting measures to avoid false positives and advancing mechanistic understanding of the eNRR process. Ammonia plays an indispensable role in global agroeconomics, chemical industries, energy carriers, and other diverse applications. To meet the demand for ammonia in these roles, the artificial synthesis of ammonia has traditionally relied on the well-established Haber–Bosch process that is commercially viable but energy intensive. Recently, the drive for sustainable alternatives has fueled interest in the development of electrochemical nitrogen reduction (eNRR) as a pathway for carbon-free ammonia synthesis. Nevertheless, research in the eNRR field remains elusive, partly because of the ominous presence of reactive nitrogen-containing species (Nr) and the lack of a thorough understanding of eNRR mechanistics. Herein, we provide an overview of efforts highlighting measures to avoid false positives and advancing mechanistic understanding of the eNRR process. two mechanisms of NH3 synthesis. In the associative mechanism, the first activation step involves the hydrogenation of N2 molecules (e.g., in enzymatic processes). In the dissociative mechanism, the breaking of the N≡N triple bond occurs first (e.g., in the Haber–Bosch process). a sampling technique that can in situ probe the layers of adsorbed species at a solid–liquid interface and provides the information of IR adsorption related to specific functional groups and chemical structure. in the eNRR research, the crucial experiments are carried out with the controlled feeding gas (both argon and 15N2), while keeping all other conditions identical to the electrolysis with 14N2 as feeding gas. an analytical technique, combining electrochemical experimentation with mass spectrometry, allowing for in situ, mass-resolved observation of gaseous or volatile species in electrochemical reactions. the efficiency with which electrical charge is transferred towards a given electrochemical reaction leading to target products. a characteristic mechanism with which some products carry one or more constituents of the catalysts’ lattice, when leaving the surface of the catalyst. For the eNRR process on transition metal nitrides, a proposed MvK mechanism involves the removal (reduction) of a surface nitride N atom to NH3, and then, the created N vacancy is replenished by N2 molecule to complete the catalytic cycle. the rate of NH3 production normalized by the geometric area of electrode (unit: mol NH3 cm−2 s−1). a spectroscopic technique critically used in the eNRR research, in which the characteristic triplet and doublet peaks for 14NH4+ and 15NH4+ are well identifiable with μM-level detection limit. a measure of the strength for a chemical bond R–X, defined as the standard enthalpy change of the fission: R–X → R + X. Here, ‘primary’ is referred to as the first dissociated chemical bond in species that contain multiple identical bonds. a surface-sensitive technique that exploits the electromagnetic properties of nanostructured metal films to enhance the vibrational bands of a molecular adlayer. a measurement technique for determining the geometric and electronic structures in a sample by its X-ray absorption characteristics, usually performed at synchrotron radiation facilities.

Factors impacting the antioxidant/prooxidant activity of tea polyphenols on lipids and proteins in oil-in-water emulsions

Abstract: Tea polyphenols (TP) may inhibit or promote the oxidation of proteins and lipids in foods, depending on system conditions. In this study, we examined the effects of TP concentration (0, 100, and 400 mg/L), solution pH (3 and 7), and the addition of ethylenediaminetetraacetic acid (0 or 20 μmol/L EDTA) on the antioxidant/prooxidant activities of TP in walnut oil-in-water (O/W) emulsions under accelerated storage conditions (50 °C for 0, 48, 96 h). At pH 3, a lower concentration of TP (100 mg/L) exhibited stronger antioxidant activity for lipids and proteins than the higher concentration (400 mg/L). At pH 7, the lower concentration of polyphenols was still more effective, while the higher concentration resulted in prooxidant activity toward the proteins. In the absence of TP, the incorporation of EDTA into the emulsions (pH 7) inhibited lipid and protein oxidation, which was attributed to its ability to chelate and inactivate the prooxidant transition metals. Interestingly, the antioxidant activity of EDTA decreased in the presence of TP. Therefore, these results suggested that TP could be used to retard protein and lipid oxidation in emulsion-based foods, but their levels should be optimized due to their complex prooxidant and antioxidant mechanisms, depending on system composition and environmental conditions.

Comparative study on the rheological properties of myofibrillar proteins from different kinds of meat

Abstract: In this study, the gel properties of myofibrillar proteins (MPs) from four meat sources (fish, beef, sheep, and pork) were compared. Oscillatory rheology measurements including temperature sweep, frequency sweep, and strain sweep were conducted to characterise the small and large deformation rheological properties of the MPs. In addition, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and scanning electron microscopy (SEM) were used to evaluate differences in the molecular weight distribution as well as the microstructures in gel among different MPs. Frequency sweep measurements showed that all MP gels were weak gels. MPs extracted from pork exhibited the highest gel strength and most compact gel structure, whereas those from fish exhibited the lowest gel strength and loosest gel structure. In addition, the MP extracted from pork (PSM) had the highest content of myosin heavy chain (MHC) and actin. In conclusion, the MPs extracted from fish source and mammalian sources varied significantly in terms of rheological properties and microstructural characteristics. These results provided useful information for developing mixed gel products with different gel strengths.

Structural characteristics and stability of salmon skin protein hydrolysates obtained with different proteases

Abstract: The aim of this work is to evaluate the effects of Neutrase, Alcalase, Flavourzyme, and Protamex on the structural characteristics and stability of salmon skin protein (SSP) hydrolysates. The results suggested that Alcalase hydrolysate had the highest degree of hydrolysis (DH, 20.07%), the lowest molecular weight (