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Effects of pre-ozonation on organic matter removal by coagulation with IPF-PACl

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Journal of Environmental Sciences 2006年第3期18卷 453-458页

作者： LIU hai-long wang Dong-sheng SHI Bao-you wang Min TANG Hong-xiao State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China School of Environmental Science and Resources Shanxi University Taiyuan 030002 China School of Water Resources and Environmental Sciences China University of Geosciences Beijing 100083 China

Ozone plays an important role as a disinfectant and oxidant in potable water treatment practice and is increasingly being used as a pre-oxidant before coagulation. The purpose of this study is to obtain insight into the mechanisms that are operative in pre-ozonized coagulation. Effects ofpre-ozonation on organic matter removal during coagulation with IPF-PAC1 were investigated by using PDA （photometric disperse analysis）, apparent molecular weight distribution and chemical fractionation. The dynamic formation of flocs during coagulation process was detected. Changes of aquatic organic matter （AOM） structure resulted from the influence of pre-ozonation were evaluated. Results show that dosage of O3 and characteristics of AOM are two of the major factors influencing the performance of O3 on coagulation. No significant coagulation-aid effect of O3 was observed for all experiments using either A1C13 or PAC1. On the contrary, with the application of pre-ozonation, the coagulation efficiency of A1C13 was significantly deteriorated, reflected by the retardation of floc formation, and the removal decreases of turbidity, DOC, and UV254. However, if PACl was used instead of AlCl3, the adverse effects of pre-ozonation were mitigated obviously, particularly when the O3 dosage was less than 0.69 （mg O3/mg TOC）. The difference between removals of UV254, and DOC indicated that pre-ozonation greatly changed the molecular structure of AOM, but its capability of mineralization was not remarkable. Only 5% or so DOC was removed by pre-ozonation at 0.6--0.8 mg/L alone. Fractionation results showed that the organic products of pre-ozonation exhibited lower molecular weight and more hydrophilicity, which impaired the removal of DOC in the following coagulation process.

关键词： natural organic matter (NOM) fractionation pre-ozonation PACl coagulation

Characterization of Impact Deformation Behavior of a Thermally Aged Duplex Stainless Steel by EBSD

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Acta Metallurgica Sinica(English Letters) 2018年第8期31卷 798-806页

作者： Gang Liu Shi-Lei Li hai-long Zhang Xi-Tao wang Yan-Li wang State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing

The effect of thermal aging on phase transformation and impact toughness of an as-cast duplex stainless steel was investigated at room temperature. After long-term thermal aging, the impact toughness decreases significantly and the cracks initiate and propagate more easily. The plastic deformation ability of the ferrite phase decreases after thermal aging,which leads to the degradation of impact toughness. High stress concentration occurs on the grain boundaries of the austenite phase in the aged materials. Meanwhile, high-stress concentration areas are also observed in the austenite phase near the grain boundaries. After long-term thermal aging, pinned dislocations in ferrite and along phase boundaries lead to the high stress concentration. Micro-cracks preferentially initiate in the ferrite phase and propagate via separation of phase boundaries. The blocking influences of spinodal decomposition precipitates and G-phase precipitates are stronger than the effect of grain boundaries and phase boundaries on the dislocation movement.

关键词： Duplex stainless steel Thermal aging Charpy impact toughness EBSD

LLTH‑YOLOv5:A Real‑Time Traffic Sign Detection Algorithm for Low‑Light Scenes

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Automotive Innovation 2024年第1期7卷 121-137页

作者： Xiaoqiang Sun Kuankuan Liu long Chen Yingfeng Cai hai wang Automotive Engineering Research Institute Jiangsu UniversityZhenjiang 212013China School of Automotive and Traffic Engineering Jiangsu UniversityZhenjiang 212013China

Traffic sign detection is a crucial task for autonomous driving ***,the performance of deep learning-based algorithms for traffic sign detection is highly affected by the illumination conditions of *** existing algo-rithms demonstrate high accuracy in well-lit environments,they suffer from low accuracy in low-light *** paper proposes an end-to-end framework,LLTH-YOLOv5,specifically tailored for traffic sign detection in low-light scenarios,which enhances the input images to improve the detection *** proposed framework comproses two stages:the low-light enhancement stage and the object detection *** the low-light enhancement stage,a lightweight low-light enhancement network is designed,which uses multiple non-reference loss functions for parameter learning,and enhances the image by pixel-level adjustment of the input image with high-order *** the object detection stage,BIFPN is introduced to replace the PANet of YOLOv5,while designing a transformer-based detection head to improve the accuracy of small target ***,GhostDarkNet53 is utilized based on Ghost module to replace the backbone network of YOLOv5,thereby improving the real-time performance of the *** experimental results show that the proposed method significantly improves the accuracy of traffic sign detection in low-light scenarios,while satisfying the real-time requirements of autonomous driving.

关键词： Deep learning Traffic sign detection Low-light enhancement YOLOv5 Object detection

Coking properties of thermal soluble constituents of coals by N-methyl-2-pyrrolidone solvent

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Journal of Iron and Steel Research International 2018年第4期25卷 378-386页

作者： hai-bin Zuo Si-yang long Jing-song wang Wen-tao Guo State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing Beijing 100083 China

Four types of coals, KL, XB, ZS and GD with different coal ranks, were dissolved with the organic solvent N-methyl-2- pyrrolidone at 350 ℃ and around 3.0 MPa pressure to obtain thermal soluble constituents （TSCs）. The yield, component and maceral group were investigated as well as their coking properties, including caking index and thermoplasticity. The results indicated that the yields of the four coals were of the following order： KL 〉 XB 〉 ZS 〉 GD. Based on the yield and the vitrinite content, coals were ranked from high to low. The ash contents of TSCs were significantly less than that of raw coals, and the TSCs contain more light components, leading to an increase in volatile matter. The patterns of Fourier transform infrared spectroscopy indicated that carbonyl was enriched in TSCs. Regarding the maceral group, TSCs were mainly composed of vitrinite which is the main reactive material and converts into binder phase in cokemaking process. Higher caking index values and fluidity were obtained in TSCs compared with the raw coals. The coking experiments with different amounts of TSCs addition were carried out. The results demonstrated that the proper TSCs addition could enhance the coke strength due to its high caking index and good fluidity.

关键词： Thermal soluble constituent Coking property Maceral group Fluidity Coal

Effect of Nb-V microalloying on the hot deformation behavior of medium Mn steels

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 360-368页

作者： Yumeng wang Qinyi Guo Bin Hu haiwen Luo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

The influence of Nb-V microalloying on the hot deformation behavior and microstructures of medium Mn steel(MMS)was investigated by uniaxial hot compression *** establishing the constitutive equations for simulating the measured flow curves,we successfully constructed deformation activation energy(Q)maps and processing maps for identifying the region of flow *** concluded the following consequences of Nb-V alloying for MMS.(i)The critical strain increases and the increment diminishes with the increasing deformation temperature,suggesting that NbC precipitates more efficiently retard dynamic recrystallization(DRX)in MMS compared with solute Nb.(ii)The deformation activation energy of MMS is significantly increased and even higher than that of some reported high Mn steels,suggesting that its ability to retard DRX is greater than that of the high Mn content.(iii)The hot workability of MMS is improved by narrowing the hot processing window for the unstable flow stress,in which fine recrystallized and coarse unrecrystallized grains are present.

关键词： medium manganese steel niobium-vanadium microalloying flow behavior dynamic recrystallization hot workability

Natural recovery of different areas of a deserted quarry in South China

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Journal of Environmental Sciences 2008年第4期20卷 476-481页

作者： DUAN Wenjun REN hai FU Shenglei wang Jun YANG long ZHANG Jinping Heshan National Field Research Station of Forest Ecosystem South China Botanical Garden the Chinese Academy of Sciences Guangzhou 510650 China Graduate University of the Chinese Academy of Sciences Beijing 100039 China

A quarry is a surface mining operated place, which produces enormous quantifies of gravel, limestone, and other materials for industrial and construction applications. Restoration and revegetation of deserted quarries are becoming increasingly important. Three areas of a typical quarry in South China： terrace for crushed materials （terrace）, spoiled mound, and remaining side slope, were investigated, to compare the existing plant species and to study the relationship between environmental factors and revegetation. The plant species composition of these three areas was found to differ significantly after eight years of natural recovery. The typical plant communities found over them were composed of gramineous herbs, ferns, and shrubs. Soil organic matter, soil moisture, and soil bulk density were considered to be the major determining factors for vegetation succession. There existed abiotic and biotic thresholds during quarrying restoration. Suggestions had been presented that could have accelerated the process of natural recovery in quarries.

关键词： natural recovery quarry vegetation environment-vegetation relationships

Sodium dehydroacetate treatment prolongs the shelf-life of'Kyoho'grape by regulating oxidative stress and DNA methylation

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Journal of Integrative Agriculture 2022年第5期21卷 1525-1533页

作者： GUO Da-long LIU hai-nan wang Zhen-guang GUO Li-li ZHANG Guo-hai College of Horticulture and Plant Protection Henan University of Science and TechnologyLuoyang 471023P.R.China Henan Engineering Technology Research Center of Quality Regulation and Controlling of Horticultural Plants Luoyang 471023P.R.China

In this study,we tested the ability of sodium dehydroacetate(SD)to extend the shelf-life of‘Kyoho’*** the different concentrations of SD tested(0,0.01,0.1 and 1.0 mmol L^(-1)),0.01 mmol L^(-1) SD was the most effective in prolonging the shelf-life of‘Kyoho’*** with the control,the weight loss rate,browning index and hydrogen peroxide(H_(2)O_(2))and malonaldehyde contents were significantly lower in the 0.01 mmol L^(-1) SD treatment,whereas the healthy berry rate,berry firmness,total soluble solids(TSS)content,ascorbic acid content and superoxide dismutase(SOD)activity were significantly *** addition,an analysis of‘Kyoho’grape DNA using methylation sensitive amplification polymorphism(MSAP)markers showed that the average DNA methylation level was significantly higher in the 0.01 mmol L^(-1) SD treatment than in the ***,these results indicate that 0.01 mmol L^(-1) SD could be used to extend the shelf-life of‘Kyoho’***,a strong connection between reactive oxygen species(ROS)metabolism and DNA methylation change during storage was revealed.

关键词： grape sodium dehydroacetate DNA methylation MSAP shelf-life

Potential application of graphene nanoplatelets as a high temperature lubricant for hot rolling

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Friction 2022年第11期10卷 1810-1823页

作者： long wang Anh Kiet TIEU Ming MA Jiaqing LI Guojuan hai Hongtao ZHU State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an 710021China School of Mechanical MaterialsMechatronic and Biomedical EngineeringFaculty of Engineering and Information SciencesUniversity of WollongongNorthfields AvenueWollongongNSW 2522Australia State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China School of Materials Science and Engineering Shaanxi University of Science and TechnologyXi’an 710021China

Graphene has been shown to be a promising solid lubricant to reduce friction and wear of the sliding counterparts,and currently is reported to only function below 600℃.In this study,its potential as a lubricant above 600℃ was studied using a ball-on-disc tribo-meter and a rolling *** results suggest that a reduction up to 50%can be obtained with graphene nanoplatelets(GnP)under lubricated conditions between 600 and 700℃ when compared with dry *** this friction reduction can last more than 3 *** 800 and 900℃,the friction reduction is stable for 70 and 40 s,respectively,which indicates that GnP can potentially provide an effective lubrication for hot metal forming *** rolling experiments on steel strips indicate that GnP reduces the rolling force by 11%,7.4%,and 6.9%at 795,890,and 960℃,*** friction reductions are attributed to the easily sheared GnP between the rubbing interfaces.A temperature higher than 600℃ will lead to the gasification of the residual graphene on the strip surface,which is believed to reduce the black contamination from traditional graphite lubricant.

关键词： graphene high temperature lubricant hot rolling tribology properties

Potential dependence in electrocatalysis: a theoretical perspective

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Science China Chemistry 2025年第1期 21-25页

作者： Leyu Liu Zhaoming Xia Zeyu wang Yinjuan Chen hai Xiao Department of Chemistry Tsinghua University Fundamental Science Center of Rare Earths Ganjiang Innovation Academy Chinese Academy of Sciences Key Laboratory of Advanced Catalytic Materials and Technology Advanced Catalysis and Green Manufacturing Collaborative Innovation Center Changzhou University

Electrocatalysis is a key technology for the new energy era and sustainable development, serving as the interface for interconversion of electrical and chemical energies, which spans a wide spectrum of applications in sustainable energy and environmental engineering. Electrocatalytic reactions including electrochemical CO2reduction reaction （eCO2RR）, hydrogen evolution reaction （HER）, and oxygen evolution/reduction reactions （OER/ORR）, hold essential promise for renewable energy technologies as well as complement the biogeochemical carbon and oxygen cycles.

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