A RuO2IrO2 electrocatalyst with an optimal composition and novel microstructure for oxygen evolving in the single cell

Feng Ye,Yanpeng Cao,Weiwei Han,Yakun Yang,Yuancheng Feng,Peng Liu,Chao Xu,Xiaoze Du,양우철,Liu Guicheng 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.3

A highly active RuO2IrO2 electrocatalyst was developed via dip-coating/calcination method for oxygen evolution reaction (OER). The catalyst on Ti substrate with a 7/3 molar ratio between Ru and Ir showed the highest electrocatalytic activity for OER among composite samples in different molar ratios. Moreover, the properties of RuO2IrO2 grown on carbon paper were evaluated by proton exchange membrane water electrolysis single cell. Compared with the micron-particle structure of RuO2IrO2 catalyst on the Ti substrate, the catalyst grown on the carbon paper showed a novel nano dendrite shape and can be used directly as the gas diffusion electrode. Owing to the large surface area of the catalyst, the nano dendrite-shaped RuO2IrO2 catalyst exhibits excellent OER performance in the single cell. Furthermore, a cell voltage of 2.50 V is achieved under 200mA cm2 at 30 oC by using the optimal composition RuO2IrO2 (Ru : Ir=7/3) and the commercial 20% Pt/C as anode and cathode, respectively.

Reusable, magnetic laser-induced graphene for efficient removal of organic pollutants from water

Jiang Ye,Wan Sijie,Zhao Weiwei,Yu Wenjie,Wang Shuaipeng,Yu Zeqi,Yang Qiu,Zhou Weihua,Liu Xiaoqing 한국탄소학회 2022 Carbon Letters Vol.32 No.4

The hybridization of graphene with magnetic nanoparticles has endowed graphene with increasing interest as the adsorbent for wastewater treatment. However, its fabrication often involves a multi-stepped chemical synthesis process. In this work, we demonstrate a facile, one-step, and solvent-free approach to fabricate Fe3O4 nanoparticle-anchored Laser-Induced Graphene (Fe3O4@LIG) as an efficient adsorbent by direct laser irradiation on a ferric acetylacetonate containing polybenzoxazine film. Raman and X-ray diffraction analysis confirm the graphene component in the adsorbent, and the morphology characterizations show that Fe3O4 nanoparticles are distributed uniformly on LIG with hierarchical meso- and macro-porous structures. Adsorption experiments indicate that Fe3O4@LIG can adsorb methylene blue (MB) from aqueous solutions in a fast and effective manner, with a maximum adsorption capacity up to 350.9 mg/g. The adsorption kinetics and isotherms are also investigated, which are well-described by the pseudo-second-order model and Langmuir model, respectively. Additionally, Fe3O4@LIG is also demonstrated with the efficient removal of a variety of organic solvents from water. The favorable adsorption behavior of Fe3O4@LIG is attributed to its unique porous structure and the molecular interactions with adsorbates. On the other hand, Fe3O4@LIG has high magnetic property, and therefore, it could be easily recovered from water and well regenerated for repeated use. With the efficient adsorption of organic pollutants, magnetic separability, and good recyclability, it is believed that the easy-fabricated Fe3O4@LIG has great potential applications in wastewater treatment.

Efficacy of combination of endo-xylanase and xylan-debranching enzymes in improving cereal bran utilization in piglet diet

Wang Weiwei,Zheng Dawen,Zhang Zhenzhen,Ye Hui,Cao Qingyun,Zhang Changming,Dong Zemin,Feng Dingyuan,Zuo Jianjun 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.11

Objective: This study was aimed to explore the efficacy of combination of endo-xylanase (Xyn) and xylan-debranching enzymes (arabinofuranosidase, Afd and feruloyl esterase, FE) in improving utilization of bran in piglet diet. Methods: In vitro experiments were firstly conducted to examine the enzymological properties of Xyn, Afd, and FE, concurrent with their effect on degradation of arabinoxylan (Abx) in bran. In vivo experiment was then implemented by allocating two hundred and seventy 35-d-old postweaning piglets into 3 groups (6 replicates/group), which received bran-containing diet supplemented with Xyn (1,600 U/kg) or its combination with Afd (0.8 U/kg) and FE (4 U/kg) or without enzyme. Results: Both Xyn, Afd, and FE are relatively stable against the changes in temperature and pH value. Combining Xyn with Afd and FE had a superiority (p<0.05) over Xyn alone and its combination with Afd or FE in promoting (p<0.05) degradation of Abx in different brans. Combined treatment with Xyn, Afd, and FE was more beneficial than Xyn alone to induce increasing trends (p<0.10) of average daily gain, final body weight and feed efficiency of piglets fed bran-containing diet. Moreover, combination of Xyn, Afd, and FE showed advantages (p<0.05) over Xyn alone in causing reductions (p<0.05) in diarrhea rate and cecal pH value, concurrent with increases (p<0.05) in cecal and colonic acetic acid and total volatile fatty acid concentrations, as well as cecal butyric acid concentration of piglets fed brancontaining diet. Conclusion: Combining Xyn with Afd and FE was more beneficial than Xyn alone in promoting degradation of Abx in bran, along with growth performance and intestinal volatile fatty acid profile of piglets received bran-containing diet. Thereby, combination of Xyn, Afd, and FE had a superior efficacy relative to Xyn alone in improving application of cereal bran in piglet diet. Objective: This study was aimed to explore the efficacy of combination of endo-xylanase (Xyn) and xylan-debranching enzymes (arabinofuranosidase, Afd and feruloyl esterase, FE) in improving utilization of bran in piglet diet.Methods: <i>In vitro</i> experiments were firstly conducted to examine the enzymological properties of Xyn, Afd, and FE, concurrent with their effect on degradation of arabinoxylan (Abx) in bran. <i>In vivo</i> experiment was then implemented by allocating two hundred and seventy 35-d-old postweaning piglets into 3 groups (6 replicates/group), which received bran-containing diet supplemented with Xyn (1,600 U/kg) or its combination with Afd (0.8 U/kg) and FE (4 U/kg) or without enzyme.Results: Both Xyn, Afd, and FE are relatively stable against the changes in temperature and pH value. Combining Xyn with Afd and FE had a superiority (p<0.05) over Xyn alone and its combination with Afd or FE in promoting (p<0.05) degradation of Abx in different brans. Combined treatment with Xyn, Afd, and FE was more beneficial than Xyn alone to induce increasing trends (p<0.10) of average daily gain, final body weight and feed efficiency of piglets fed bran-containing diet. Moreover, combination of Xyn, Afd, and FE showed advantages (p<0.05) over Xyn alone in causing reductions (p<0.05) in diarrhea rate and cecal pH value, concurrent with increases (p<0.05) in cecal and colonic acetic acid and total volatile fatty acid concentrations, as well as cecal butyric acid concentration of piglets fed bran-containing diet.Conclusion: Combining Xyn with Afd and FE was more beneficial than Xyn alone in promoting degradation of Abx in bran, along with growth performance and intestinal volatile fatty acid profile of piglets received bran-containing diet. Thereby, combination of Xyn, Afd, and FE had a superior efficacy relative to Xyn alone in improving application of cereal bran in piglet diet.

Capacitor voltage feedforward decoupling control based on third harmonic injection modulation for five-level active neutral point clamped converter

Nie, Ziling,Ye, Weiwei,Zhu, Junjie,Xu, Jie The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.6

For the five-level active neutral point clamped (5L-ANPC) converter, the coupling problem between the DC-link capacitor voltages and flying-capacitor (FC) voltages will increase the capacitor voltage fluctuations. The capacitor voltage fluctuations and current harmonics of the space vector pulse width modulation (SVPWM) are less than those of the sinusoidal pulse width modulation (SPWM), because the maximum linear modulation index of the SVPWM is higher than that of the SPWM. However, SVPWM has difficulty in realizing the decoupling control of the capacitor voltages, and the computation complexity of SVPWM is much higher than that of SPWM. This paper proposes a third harmonic injection modulation algorithm for the 5L-ANPC converter. The proposed algorithm injects the third harmonic into the modulation waves of SPWM, which makes the maximum linear modulation index of SPWM the same as that of SVPWM, to reduce the capacitor voltage fluctuations and current harmonics. The calculation of the third harmonic only requires a standard sorting algorithm and a simple linear operation; thus, it is easy to implement. Based on the third harmonic injection modulation algorithm, two variables are introduced to control the neutral point (NP) current and the FC current. And the two variables are used to feedforward compensate the modulation waves, realizing the decoupling control of the capacitor voltages. The proposed decoupling control method can further reduce the capacitor voltage fluctuations. Experimental results are presented to verify the validity of the proposed algorithm.

Network Selection Algorithm Based on Spectral Bandwidth Mapping and an Economic Model in WLAN<E heterogeneous networks

( Pan Su ),( Zhou Weiwei ),( Gu Qingqing ),( Ye Qiang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.1

Future wireless network aims to integrate different radio access networks (RANs) to provide a seamless access and service continuity. In this paper, a new resource denotation method is proposed in the WLAN and LTE heterogeneous networks based on a concept of spectral bandwidth mapping. This method simplifies the denotation of system resources and makes it possible to calculate system residual capacity, upon which an economic model-based network selection algorithm is designed in both under-loaded and over-loaded scenarios in the heterogeneous networks. The simulation results show that this algorithm achieves better performance than the utility function-based access selection (UFAS) method proposed in [12] in increasing system capacity and system revenue, achieving load balancing and reducing the new call blocking probability in the heterogeneous networks.

Three-coil Magnetically Coupled Resonant Wireless Power Transfer System with Adjustable-position Intermediate Coil for Stable Transmission Characteristics

Chen, Xuling,Chen, Lu,Ye, Weiwei,Zhang, Weipeng The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

In magnetically coupled resonant (MCR) wireless power transfer (WPT) systems, the introduction of additional intermediate coils is an effective means of improving transmission characteristics, including output power and transmission efficiency, when the transmission distance is increased. However, the position of intermediate coils in practice influences system performance significantly. In this research, a three-coil MCR WPT system is adopted as an exemplification for determining how the spatial position of coils affects transmission characteristics. With use of the fundamental harmonic analysis method, an equivalent circuit model of the system is built to reveal the relationship between the output power, the transmission efficiency, and the spatial scales, including the axial, lateral, and angular misalignments of the intermediate and receiving coils. Three cases of transmission characteristics versus different spatial scales are evaluated. Results indicate that the system can achieve relatively stable transmission characteristics with deliberate adjustments in the position of the intermediate and receiving coils. A prototype of the three-coil MCR WPT system is built and analyzed, and the experimental results are consistent with those of the theoretical analysis.

Three-coil Magnetically Coupled Resonant Wireless Power Transfer System with Adjustable-position Intermediate Coil for Stable Transmission Characteristics

Xuling Chen,Lu Chen,Weiwei Ye,Weipeng Zhang 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

In magnetically coupled resonant (MCR) wireless power transfer (WPT) systems, the introduction of additional intermediatecoils is an effective means of improving transmission characteristics, including output power and transmission efficiency, whenthe transmission distance is increased. However, the position of intermediate coils in practice influences system performancesignificantly. In this research, a three-coil MCR WPT system is adopted as an exemplification for determining how the spatialposition of coils affects transmission characteristics. With use of the fundamental harmonic analysis method, an equivalentcircuit model of the system is built to reveal the relationship between the output power, the transmission efficiency, and thespatial scales, including the axial, lateral, and angular misalignments of the intermediate and receiving coils. Three cases oftransmission characteristics versus different spatial scales are evaluated. Results indicate that the system can achieve relativelystable transmission characteristics with deliberate adjustments in the position of the intermediate and receiving coils. A prototypeof the three-coil MCR WPT system is built and analyzed, and the experimental results are consistent with those of the theoreticalanalysis.

Production of Recombinant Human Papillomavirus Type 52 L1 Protein in Hansenula polymorpha Formed Virus-Like Particles

Liu, Cunbao,Yao, Yufeng,Yang, Xu,Bai, Hongmei,Huang, Weiwei,Xia, Ye,Ma, Yanbing The Korean Society for Microbiology and Biotechnol 2015 Journal of microbiology and biotechnology Vol.25 No.6

Human papillomavirus (HPV) type 52 is a high-risk HPV responsible for cervical cancer. HPV type 52 is common around the world and is the most common in some Asian regions. The available prophylactic HPV vaccines protect only from HPV types 16 and 18. Supplementing economical vaccines that target HPV type 52 may satisfactorily complement available prophylactic vaccines. A codon-adapted HPV 52 L1 gene was expressed in the methylotrophic yeast Hansenula polymorpha, which is used as an industrial platform for economical hepatitis B surface antigen particle production in China. We found that the recombinant proteins produced in this expression system could form virus-like particles (VLPs) with diameters of approximately 50 nm. This study suggests that the HPV 52 VLPs produced in this platform may satisfactorily complement available prophylactic vaccines in fighting against HPVs prevalent in Asia.

Appropriate nitrogen application enhances saponin synthesis and growth mediated by optimizing root nutrient uptake ability

Wei, Wei,Ye, Chen,Huang, Hui-Chuan,Yang, Min,Mei, Xin-Yue,Du, Fei,He, Xia-Hong,Zhu, Shu-Sheng,Liu, Yi-Xiang The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.4

Background: Cultivation of medicinal crops, which synthesize hundreds of substances for curative functions, was focused on the synthesis of secondary metabolites rather than biomass accumulation. Nutrition is an important restrict factor for plant growth and secondary metabolites, but little attention has been given to the plasticity of nutrient uptake and secondary metabolites synthesis response to soil nitrogen (N) change. Methods: Two year-field experiments of Sanqi (Panax notoginseng), which can synthesize a high level of saponin in cells, were conducted to study the effects of N application on the temporal dynamics of biomass, nutrient absorption, root architecture and the relationships between these parameters and saponin synthesis. Results: Increasing N fertilizer rates could improve the dry matter yields and nutrient absorption ability through increasing the maximum daily growth (or nutrient uptake) rate. Under suitable N level (225 kg/ha N), Sanqi restricted the root length and surface and enhanced the root diameter and N uptake rate per root length (NURI) to promote nutrient absorption, but the opposite status of Sanqi root architecture and NURI was found when soil N was deficient. Furthermore, increasing N rates could promote the accumulation of saponin in roots through improving the NURI, which showed a significant positive relationship with the content of saponin in the taproots. Conclusion: Appropriate N fertilizer rates could optimize both root architecture and nutrient uptake efficiency, then promote both the accumulation of dry matter and the synthesis of saponins.

Adaptive Differentiated Integrated Routing Scheme for GMPLS-based Optical Internet

Wei, Wei,Zeng, Qingji,Ye, Tong,Lomone, David The Korea Institute of Information and Commucation 2004 Journal of communications and networks Vol.6 No.3

A new online multi-layer integrated routing (MLIR) scheme that combines IP (electrical) layer routing with WDM (optical) layer routing is investigated. It is a highly efficient and cost-effective routing scheme viable for the next generation integrated optical Internet. A new simplified weighted graph model for the integrated optical Internet consisted of optical routers with multi-granularity optical-electrical hybrid switching capability is firstly proposed. Then, based on the proposed graph model, we develop an online integrated routing scheme called differentiated weighted fair algorithm (DWFA) employing adaptive admission control (routing) strategies with the motivation of service/bandwidth differentiation, which can jointly solve multi-layer routing problem by simply applying the minimal weighted path computation algorithm. The major objective of DWFA is fourfold: 1) Quality of service (QoS) routing for traffic requests with various priorities; 2) blocking fairness for traffic requests with various bandwidth granularities; 3) adaptive routing according to the policy parameters from service provider; 4) lower computational complexity. Simulation results show that DWFA performs better than traditional overlay routing schemes such as optical-first-routing (OFR) and electrical-first-routing (EFR), in terms of traffic blocking ratio, traffic blocking fairness, average traffic logical hop counts, and global network resource utilization. It has been proved that the DWFA is a simple, comprehensive, and practical scheme of integrated routing in optical Internet for service providers.