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Nitrogen and phosphorus removal in pilot-scale anaerobic-anoxic oxidation ditch system

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Journal of Environmental Sciences 2008年第4期20卷 398-403页

作者： PENG Yongzhen HOU hongxun WANG Shuying CUI youwei Zhiguo Yuan Key Laboratory of Beijing for Water Environment Recovery Engineering Beijing University of Technology Beijing 100022 China Advanced Wastewater Management Centre （AWMC） the University of Queensland St. Lucia Brisbane 4072 Australia

To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal （SNDPR）, a whole course of SNDPR damage and recovery was studied in a pilot-scale, anaerobicanoxic oxidation ditch （OD）, where the volumes of anaerobic zone, anoxic zone, and ditches zone of the OD system were 7, 21, and 280 L, respectively. The reactor was fed with municipal wastewater with a flow rate of 336 L/d. The concept of simultaneous nitrification and denitrification （SND） rate （rSND） was put forward to quantify SND. The results indicate that：（1） high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase, total nitrogen （TN） and total phosphate （TP） removal rates were 80% and 85%, respectively; （2） when the system was aerated excessively, the stability of SND was damaged, and rSND dropped from 80% to 20% or less; （3） the natural logarithm of the ratio of NOx to NH4^＋ in the effluent had a linear correlation to oxidation-reduction potential （ORP）; （4） when NO3^- was less than 6 mg/L, high phosphorus removal efficiency could be achieved; （5） denitrifying phosphorus removal （DNPR） could take place in the anaerobic-anoxic OD system. The major innovation was that the SND rate was devised and quantified.

关键词： oxidation ditch biological nitrogen removal biological phosphorus removal simultaneous nitrification and denitrification (SND) pilot scale municipal wastewater

Experimental and numerical investigations of scale-up effects on the hydrodynamics of slurry bubble columns

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Chinese Journal of Chemical Engineering 2016年第8期24卷 963-971页

作者： Zhaoqi Li Xiaoping Guan Lijun Wang youwei Cheng Xi Li Department of Chemical and Biological Engineering Zhejiang University

Experiments and simulations were conducted for bubble columns with diameter of 0.2 m(180 mm i.d.), 0.5 m(476 mm i.d.) and 0.8 m(760 mm i.d.) at high superficial gas velocities(0.12–0.62 m·s-1) and high solid concentrations(0–30 vol%). Radial profiles of time-averaged gas holdup, axial liquid velocity, and turbulent kinetic energy were measured by using in-house developed conductivity probes and Pavlov tubes. Effects of column diameter, superficial gas velocity, and solid concentration were investigated in a wide range of operating conditions. Experimental results indicated that the average gas holdup remarkably increases with superficial gas velocity, and the radial profiles of investigated flow properties become steeper at high superficial gas velocities. The axial liquid velocities significantly increase with the growth of the column size, whereas the gas holdup was slightly affected. The presence of solid in bubble columns would inhibit the breakage of bubbles, which results in an increase in bubble rise velocity and a decrease in gas holdup, but time-averaged axial liquid velocities remain almost the same as that of the hollow column. Furthermore, a 2-D axisymmetric k–ε model was used to simulate heterogeneous bubbly flow using commercial code FLUENT 6.2. The lateral lift force and the turbulent diffusion force were introduced for the determination of gas holdup profiles and the effects of solid concentration were considered as the variation of average bubble diameter in the model. Results predicted by the CFD simulation showed good agreement with experimental data.

关键词： Bubble column CFD Hydrodynamics Multiphase flow Scaling-up Solid concentration

Bi-level Optimal Planning of Voltage Regulator in Distribution Systems Considering Maximization of Incentive-based Photovoltaic Energy Integration

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CSEE Journal of Power and Energy Systems 2023年第6期9卷 2008-2017页

作者： Xu Xu youwei Jia Chun Sing Lai Minghao Wang Zhao Xu Department of Electrical and Electronic Engineering Southern University of Science and TechnologyShenzhenChina Department of Electrical Engineering The Hong Kong Polytechnic UniversityHung HomHong Kong SARChina Department of Electrical and Electronic Engineering University Key Laboratory of Advanced Wireless Communications of Guangdong ProvinceSouthern University of Science and TechnologyShenzhen 515100China Department of Electronic and Computer Engineering Brunel Institute of Power SystemsBrunel University LondonLondonUB83PH United Kingdom Department of Electrical Engineering Shenzhen Research InstituteThe Hong Kong Polytechnic UniversityHung HomHong Kong SARChina

This paper focuses on optimal voltage regulator(VR)planning to maximize the photovoltaic(PV)energy integration in distribution *** describe the amount of dynamic PV energy that can be integrated into the power system,the concept of PV accommodation capability(PVAC)is introduced and modeled with *** proposed planning model is formulated as a Benders decomposition based bi-level stochastic optimization *** the upper-level problem,VR planning decisions and PVAC are determined via mixed integer linear programming(MILP)before considering *** in the lower-level problem,the feasibility of first-level results is checked by critical network constraints(*** magnitude constraints and line capacity constraints)under uncertainties considered by time-varying loads and PV *** this paper,these uncertainties are represented in the form of operational scenarios,which are generated by the Gaussian copula theory and reduced by a well-studied backward-reduction *** modified IEEE 33-node distribution grid is utilized to verify the effectiveness of the proposed *** results demonstrate that a PV energy integration can be significantly enhanced after optimal voltage regulator planning.

关键词： Bi-level stochastic optimization problem critical network constraints photovoltaic energy integration uncertainties voltage regulator planning

Achieving excellent bandwidth absorption by a mirror growth process of magnetic porous polyhedron structures

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Nano Research 2016年第6期9卷 1813-1822页

作者： Hualiang Lv Haiqian Zhang Jun Zhao Guangbin Ji youwei Du College of Materials Science and Technology Nonjing University of Aeronautics and Astronautics Nonjing 211100 Chino School of Chemical and Biomedical Engineering Nanyang Technological University Singapore 637459 Singapore School of Materials Sciences and Engineering Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore National Laboratory of Solid State Microstructures Nanjing University Nanjing 210093 China

A symmetrical Fe2O3/BaCO3 hexagonal cone structure having a height of 10 um and an edge length of -4um is reported, obtained using a common solvothermal process and a mirror growth process. Focused ion beam and high-resolution transmission electron microscopy techniques revealed that α-Fe2O3 was the single crystal feature present. Ba ions contributed to the formation of symmetrical structures exhibited in the final composites. Subsequently, porous magnetic symmetric hexagonal cone structures were used to study the observed intense electromagnetic wave interference. Electromagnetic absorption performance studies at 2-18 GHz indicated stronger attenuation electromagnetic wave ability as compared to other shapes such as spindles, spheres, cubes, and rods. The maximum absorption frequency bandwidth was at 7.2 GHz with a coating thickness d = 1.5 mm. Special structures and the absence of BaCO3 likely played a vital role in the excellent electromagnetic absorption properties described in this research.

关键词： symmetrical hexagonalcone structure Fe203/BaC03 single crystal porous magnetic absorber effective frequencybandwidth

A retroactive approach to microgrid real-time scheduling in quest of perfect dispatch solution

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Journal of Modern Power Systems and Clean Energy 2019年第6期7卷 1608-1618页

作者： youwei JIA Xue LYU Chun Sing LAI Zhao XU Minghua CHEN Department of Electrical and Electronic Engineering Southern University of Science and TechnologyShenzhenChina Department of Electrical Engineering The Hong Kong Polytechnic UniversityHong KongChina Department of Electrical Engineering School of AutomationGuangdong University of TechnologyGuangzhouChina School of Civil Engineering Faculty of EngineeringUniversity of LeedsLeedsUK The Chinese University of hong Kong Hong KongChina

As an emerging paradigm in distributed power systems,microgrids provide promising solutions to local renewable energy generation and load demand ***,the intermittency of renewables and temporal uncertainty in electrical load create great challenges to energy scheduling,especially for small-scale *** of deploying stochastic models to cope with such challenges,this paper presents a retroactive approach to real-time energy scheduling,which is prediction-independent and computationally *** case studies were conducted using 3-year-long real-life system data,and the results of simulations show that the cost difference between the proposed retroactive approach and perfect dispatch is less than 11%on average,which suggests better performance than model predictive control with the cost difference at 30%compared to the perfect dispatch.

关键词： Microgrid Renewables Real-time scheduling Perfect dispatch Grid integration

Effects of Mechanical Alloying Parameters on the Microstructures of Nanocrystalline Cu-5 wt% Cr Alloy

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Journal of Wuhan University of Technology(Materials Science) 2013年第1期28卷 192-195页

作者：史昆玉薛丽红 YAN youwei SHEN Tao State Key Laboratory of Materials Processing and Die & Mould Technology Huazhong University of Science and Technology

Nanocrystalline Cu-5 wt%Cr alloy powders were fabricated by mechanical alloying （MA）, The effects of MA processing parameters on the crystallite size, solid solubility, and microstructures of the Cu- 5 wt%Cr alloys were investigated including type and size distribution of the grinding medium and ball-topowder weight ratio （BPR）. The results show that the crystallites were refined effectively and solid solubility of Cr in Cu was extended when heavier ball and higher BPR were adopted. The maximum solubility is extended up to 5.6 at% （namely 4.6 wt%） Cr in Cu by use of a combination of large and small size WC-Co balls with BPR of 30：1. A Cn-5 wt%Cr supersaturated solid solution alloy bulk is obtained by spark plasma sintering the as-milled powders at 900 ℃ for 5 min.

关键词： mechanical alloying Cu-Cr alloys nanocrystalline solid solubility

A new high-pressure die casting Mg-Gd-Sm-Al alloy with high strength-ductility synergy

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Journal of Rare Earths 2024年第12期42卷 2239-2248页

作者： Shuhui Lv youwei Cheng Bo Deng Tao Xu Xin Qiu Qiang Yang School of Materials Science and Engineering Changchun University of Science and Technology State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences Kashui International Holdings Limited

A high-pressure die casting（HPDC） Mg-5Gd-1.5Sm-0.7Al alloy was newly developed and exhibits outstanding strength-ductility synergy, with the yield strength and the tensile elongation to fracture being approximately 200 MPa and 8.5%, respectively. This alloy has two types of a-Mg grains: coarse a1-Mg(（46 ± 18） μm) and fine a2-Mg(（9.2 ± 2.3） μm) grains, and various Al-GS（GS = Gd and Sm） particles located at grain boundaries while clear solute-atom segregation near grain boundaries with limited or free intermetallic particles. Characterizations using Cs-corrected high-angle annular dark-field scanning transmission electron microscopy（HAADF-STEM） indicate the crystal structures of Al-GS phases. After aging, dense β'precipitates and chain-shaped β''-like structures precipitated near grain boundaries while a high density of ultrafine β''-（Mg,Al）3Sm precipitates and Al-GS clusters formed in grain center. Relatively fine grains, Al-GS primary particles, solute-atom segregation near grain boundaries, and/or multiple precipitates contribute to the high strength of the studied alloy, while the multi-scale a-Mg grains,variety of intermetallic particles but discontinuous skeleton, and the multi-typed precipitated lead to its satisfactory ductility.

关键词： magnesium alloys strength-ductility synergy intermetallic phases scanning/transmission electron microscopy (STEM) precipitate rare earths

REE Characteristics of a New Uranium Mineral from the Xianshi Uranium Deposit, South China

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Acta Geologica Sinica(English Edition) 2018年第4期92卷 1667-1669页

作者： LUO Jincheng HU Ruizhong BI Xianwu CHEN youwei State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences Department of Geological Sciences University of Manitoba

Objective Galuskin et al. （2011） firstly discovered that vorlanite （CaU^6＋/4＋）04 is a rare Ca-rich mineral with a fluorite-type structure, which is isostructural with uraninite （U^4＋O2）. Previous studies of the Xianshi granite-related uranium deposit reported that uraninite and pyrite are the major ore minerals whereas galena, clausthalite （PbSe）, and pyrite are minor phases in the ores. A more detailed petrographic and geochronological study of the uranium minerals from the Xianshi deposit showed that there are three distinct types of uraninite-bearing assemblages which formed at three mineralization episodes （Fig. la; Luo et al., 2015）.

关键词： REE Characteristics of a New Uranium Mineral from the Xianshi Uranium Deposit Ca South China

Drosophila models used to simulate human ATP1A1 gene mutations that cause Charcot-Marie-Tooth type 2 disease and refractory seizures

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Neural Regeneration Research 2025年第1期20卷 265-276页

作者： Yao Yuan Lingqi Yu Xudong Zhuang Dongjing Wen Jin He Jingmei hong Jiayu Xie Shengan Ling Xiaoyue Du Wenfeng Chen Xinrui Wang Institute of Life Sciences College of Biological Science and EngineeringFuzhou UniversityFuzhouFujian ProvinceChina NHC Key Laboratory of Technical Evaluation of Fertility Regulation for Non-human Primate(Fujian Maternity and Child Health Hospital) FuzhouFujian ProvinceChina Medical Research Center Fujian Maternity and Child Health HospitalCollege of Clinical Medicine for Obstetrics&Gynecology and PediatricsFujian Medical UniversityFuzhouFujian ProvinceChina Department of Neurology and Institute of Neurology of The First Affiliated Hospital Institute of Neuroscienceand Fujian Key Laboratory of Molecular NeurologyFujian Medical UniversityFuzhouFujian ProvinceChina

Certain amino acids changes in the human Na^(+)/K^(+)-ATPase pump,ATPase Na^(+)/K^(+)transporting subunit alpha 1(ATP1A1),cause Charcot-Marie-Tooth disease type 2(CMT2)disease and refractory *** develop in vivo models to study the role of Na^(+)/K^(+)-ATPase in these diseases,we modified the Drosophila gene homolog,Atpα,to mimic the human ATP1A1 gene mutations that cause *** located within the helical linker region of human ATP1A1(I592T,A597T,P600T,and D601F)were simultaneously introduced into endogenous Drosophila Atpαby CRISPR/Cas9-mediated genome editing,generating the Atpα^(TTTF)*** addition,the same strategy was used to generate the corresponding single point mutations in flies(Atpα^(I571T),Atpα^(A576T),Atpα^(P579T),and Atpα^(D580F)).Moreover,a deletion mutation(Atpα^(mut))that causes premature termination of translation was generated as a positive *** these alleles,we found two that could be maintained as homozygotes(Atpα^(I571T)and Atpα^(P579T)).Three alleles(Atpα^(A576T),Atpα^(P579)and Atpα^(D580F))can form heterozygotes with the Atpαmut *** found that the Atpαallele carrying these CMT2-associated mutations showed differential phenotypes in *** heterozygous for Atpα^(TTTF)mutations have motor performance defects,a reduced lifespan,seizures,and an abnormal neuronal *** Drosophila models will provide a new platform for studying the function and regulation of the sodium-potassium pump.

关键词： ATP1A1 Atpα bang-sensitive paralysis Charcot-Marie-Tooth disease type 2 CRISPR/Cas9 homology-directed repair Na^(+)/K^(+)-ATPase point mutation seizures sodium pump