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资水下游某石煤矿区沉积物重金属污染评价和来源解析

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农业环境科学学报 2024年第5期43卷 1123-1130页

作者：代馨悦申志成胡华玲师华定何泽新李藜刘安富中国环境科学研究院北京100012 生态环境部土壤与农业农村生态环境监管技术中心北京100012

以资水下游某石煤矿区为研究区域,分析该矿区河流沉积物中重金属的空间分布、污染程度和来源。研究共采集了28个表层沉积物样本,并对其中8种重金属的含量进行了测定,包括镉(Cd)、铬(Cr)、汞(Hg)、砷(As)、铅(Pb)、铜(Cu)、镍(Ni)和锌(Zn... 详细信息

以资水下游某石煤矿区为研究区域,分析该矿区河流沉积物中重金属的空间分布、污染程度和来源。研究共采集了28个表层沉积物样本,并对其中8种重金属的含量进行了测定,包括镉(Cd)、铬(Cr)、汞(Hg)、砷(As)、铅(Pb)、铜(Cu)、镍(Ni)和锌(Zn)。采用地累积指数和潜在生态风险指数进行重金属污染评价,运用主成分分析(PCA)、正定矩阵因子(PMF)等方法识别重金属污染来源。结果表明,除Cr外,Cd、Hg、As、Pb、Cu、Zn、Ni含量的中值均高于洞庭湖水系沉积物背景值。其中,Cd、As含量超标问题较为严重,超过《土壤环境质量农用地土壤污染风险管控标准(试行)》(GB 15618—2018)风险筛选值的样点比率分别为96.55%、58.62%。地累积指数和潜在生态风险指数分析表明,沉积物中Cd、Hg污染最为严重,Cr污染程度最低。沉积物重金属主要来源为石煤开采源、交通和农业混合源、自然源以及大气沉降源,贡献率分别为33.8%、20.4%、17.7%和28.1%。研究表明,研究区沉积物受到石煤开采影响,重金属Cd超标严重,应加强管控。

关键词：重金属资水沉积物石煤来源解析污染评价

Formation of the Yalong Downstream Terraces in the SE Tibetan Plateau and Its Implication for the Uplift of the Plateau

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Acta Geologica Sinica(English Edition) 2015年第2期89卷 542-560页

作者： he zexin ZHANG Xujiao QIAO Yansong BAO Shuyan LU Chunyu he Xiangli School of the Earth Sciences and Resources China University of Geosciences Institute of Geomechanics Chinese Academy of Geological Sciences Key Laboratory of Neotectonic Movement and Geohazard

The Yalong River is an important river that runs across the abruptly changing terrain of the SE Tibetan Plateau. The terraces and Quaternary sediments in its valleys preserve the information of tectonic uplift, climate changes, and landform evolution since the Middle Pleistocene. Based on geomorphological, sedimentological, and chronological investigations, 6-8 terraces are identified in the lower reaches of Yalong catchment and its tributary--the Anning River. The electron spin resonance （ESR） or optically stimulated luminescence （OSL） data on the alluvial sediments in the upper portion of terraces indicate that they formed in 1.10, 0.90, 0.72, 0.06-0.04, 0.03-0.02, and 0.01 Ma. Tectonic uplift and the climatic cycle controlled the formation of the Yalong River terraces. The former dominated the dissection depths and incision rates, whereas the latter controlled the transformation between accumulation, which developed during the glacial period, and incision, which developed during the glacial-interglacial transition. The Yalong downstream incised rapidly from 1.10 to 0.72 Ma and rapidly from 0.06 Ma until the present; the terraces developed during these two periods. The incision rates in space during the two periods indicate the uplifting extent of the Jinpingshan area, which decreases toward the east and the south. The results reveal two rapidly uplifting stages in the SE Tibetan Plateau, including an accelerated uplifting since 0.06 Ma. Since the Middle Pleistocene, the tectonic uplift of the SE and NE parts of the Tibetan Plateau is synchronous, according to the same development stages of the river terraces of the Yalong downstream and the Yellow River in the Lanzhou area of the NE Tibetan Plateau. The difference in the horizontal displacement between the Xianshuihe Fault and the Anninghe Fault bend resulted in the rapid uplift of the Jinpingshan area. The incision rate for the spatial distribution of the Yalong downstream is the geomorphologicai response of cru

关键词： Yalong downstream Anning River river terrace tectonic uplift climate change the Tibetan Plateau

Paleoearthquake Investigation along the Chenghai Fault Zone since~500 ka,Southeast Margin of the Tibetan Plateau

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Acta Geologica Sinica(English Edition) 2021年第4期95卷 1332-1345页

作者： YANG Shuaibin QIAO Yansong WU Zhonghai ZHANG Xujiao QI Lin he zexin LIANG Ying Institute of Geomechanics Chinese Academy of Geological SciencesBeijing 100081China The Key Laboratory of Active Tectonics and Crustal Stability Assessment Beijing 100081China School of Geosciences and Resources China University of GeosciencesBeijing 100083China

The Chenghai fault zone is located in the Sichuan–Yunnan rhombus block,which is surrounded by the Honghe River,Xianshuihe–Xiaojiang,and Jinsha River fault *** a mid-continental active fault,it is one of the most important seismogenic fractures in the southeast margin of the Tibetan *** seismic study is an important supplement to the historical seismic record;therefore,identification of paleoearthquake events in this region is of great significance to reveal the pattern and mechanism of earthquake *** this study,detailed investigation has been carried out on the earthquake traces that formed in the Quaternary sediments in the Jinsha River section of the Chenghai fault zone,and samples for dating chronology testing were also *** paleoearthquake traces were discovered in the field,including earthquake fissions,dammed lake sediments and landslides,earthquake-generated rock falls,seismic faults,and sand liquefaction *** collected samples were tested using optically stimulated luminescence,electron-spin resonance,and U-series methods.A total of 68 chronological samples were dated,combined with the results of field investigations,and 10 large paleoearthquake events were discovered in this region since 500 ka,which are at approximately 450,400,345,300,250,190,155,105,75,and 25 *** tectonic activity periods that produced multiple paleoearthquake events were identified since 500 *** study identifies paleoearthquake events in longer scales,larger spaces,and more extensive sediments,which provides new perspectives and new ideas for paleoearthquake research.

关键词： paleoearthquake earthquake fission dammed lake earthquake-generated rock fall Chenghai fault zone

Intensification of the East Asian Monsoon in Southern China at about300-400 kaBP Inferred from Eolian Deposits in the Middle-lower Reaches of the Yangtze River

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Acta Geologica Sinica(English Edition) 2017年第3期91卷 1095-1108页

作者： QI Lin QIAO Yansong LI Yuehui WANG Yan PENG Shasha he zexin YANG Shuaibin HAN Chao ZHANG Xujiao School of Earth Sciences and Resources China University of Geosciences Institute of Geomechanics Chinese Academy of Geological Sciences Key Laboratory of Neotectonic Movement & Geohazard

In the East Asian monsoon region, eolian deposits widely distributed in the middle-lower reaches of the Yantgze River are among the best materials available for studies on Quaternary climate change in the subtropical zone of Southern China. Typical eolian deposits in this region include upper Xiashu Loess （XL） and underlying Vermiculated Red Soil （VRS） layers. In this paper, chronological and paleoclimatic studies are conducted on an eolian deposit sequence near Jiujiang （J J） city in northern Jiangxi province. A magnetostratigraphic study, combined with optically stimulated luminescence （OSL） dating, is conducted on the JJ section and provides further evidence that eolian deposits in the middle-lower reaches of the Yangtze River have been formed since the late Early Pleistocene, and that the boundary age between the XL and VRS layers is about 300-400 kaBP. In grain-size records of the JJ section, the median grain-size and content of the 〉30μn size fraction increase sharply after 300-400 kaBP, representing an East Asian winter monsoon intensification event. Further pollen analysis reveals differing pollen assemblages before and after 300-400 kaBP： there is an evident increase in plants adapted to grow in a warm humid environment after 300-400 kaBP, implying an increase in precipitation caused by intensification of the East Asian summer monsoon. Global ice volume and uplift of the Tibet Plateau （TP） are regarded as crucial factors influencing variations of the East Asian monsoon on a long-term scale. The deep-sea JlSO record, which reflects variations in global ice volume, shows no obvious change after 300-400 kaBP. Moreover, the influence of global ice volume changes on the East Asian summer and winter monsoons is inverse; the global ice volume increase （decrease） implies a strengthened （weakened） winter monsoon and weakened （strengthened） summer monsoon. We therefore interpret the coupled intensifications of the East Asian summer and winter monsoons at about 300-40

关键词： Middle-lower Yangtze River eolian deposit magnetostratigraphy grain-size pollen EastAsian monsoon

Rapid fabrication of modular 3D paper-basedmicrofluidic chips using projection-based 3D printing

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Bio-Design and Manufacturing 2024年第5期7卷 611-623页

作者： Mingjun Xie zexin Fu Chunfei Lu Sufan Wu Lei Pan Yong he Yi Sun Ji Wang Plastic and Reconstructive Surgery Center Department of Plastic and Reconstructive SurgeryZhejiang Provincial People’s HospitalAffiliated People’s HospitalHangzhou Medical CollegeHangzhou 310014China State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310058China Key Laboratory of Materials Processing and Mold Zhengzhou UniversityZhengzhou 450002China Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province College of Mechanical EngineeringZhejiang UniversityHangzhou 310058China Cancer Center Zhejiang UniversityHangzhou 310058China

Paper-based microchips have different advantages,such as better biocompatibility,simple production,and easy handling,making them promising candidates for clinical diagnosis and other *** study describes amethod developed to fabricate modular three-dimensional(3D)paper-based microfluidic chips based on projection-based 3D printing(PBP)technology.A series of two-dimensional(2D)paper-based microfluidic modules was designed and *** evaluating the effect of exposure time on the accuracy of the flow channel,the resolution of this channel was experimentally ***,several 3D paper-based microfluidic chips were assembled based on the 2D ones using different methods,with good channel ***-based 2D and hydrogel-based 3D cell culture systems based on 3D paper-based microfluidic chips were verified to be ***,by combining extrusion 3D bioprinting technology and the proposed 3D paper-based microfluidic chips,multiorgan microfluidic chips were established by directly printing 3D hydrogel structures on 3D paperbased microfluidic chips,confirming that the prepared modular 3D paper-based microfluidic chip is potentially applicable in various biomedical applications.

关键词： Paper-based microfluidic chip Projection-based 3D printing(PBP) Modularization Cell culture

Effect of grain boundary diffusion of terbium on mode of mechanical fracture of sintered NdFeB magnets

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Journal of Rare Earths 2024年第4期42卷 696-704页

作者： zexin Lu Tinghui Wang Jianjun Jiang Bizhang Zheng Lijing Yang Xingqi he Anli Lin Shengzhi Dong Zhenlun Song CAS Key Laboratory of Magnetic Materials and Devices Zhejiang Province Key Laboratory of Magnetic Materials and Application TechnologyNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China Faculty of Mechanical Engineering and Mechanics Ningbo UniversityNingbo315211China Ningbo Xinqi Precision Magnetism Steel Co. Ltd..Ningbo315156China Center for Advanced Measurement Science National Institute of MetrologyBeijing102200China Division of Functional Materials Central Iron&Steel Research InstituteBeijing100081China

Grain boundary diffusion process(GBDP)is a widely used method of increasing the coercivity of sintered NdFeB *** this study,the effects of the GBDP on the bending strength and microhardness of sintered NdFeB magnets and the fracture mode were *** show that the bending strength of magnets is reduced by pickling and heat treatment and greatly recove rs after heavy rare earth element(Tb)grain boundary *** pickling and the heat treatment cause a slight decrease in *** with the recovery of the bending strength,the hardness decreases after the *** fracture mode of bended magnets changes from intergranular to *** study helps in further improving the mechanical and magnetic properties of sintered NdFeB magnets.

关键词： Sintered NdFeB magnets Grain boundary diffusionprocess Bending strength heavy rare earth element Coercivity

NeurstrucEnergy:A bi-directional GNN model for energy prediction of neural networks in IoT

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Digital Communications and Networks 2024年第2期10卷 439-449页

作者： Chaopeng Guo Zhaojin Zhong zexin Zhang Jie Song Software Campus Northeastern UniversityShenyang110000LiaoningChina

A significant demand rises for energy-efficient deep neural networks to support power-limited embedding devices with successful deep learning applications in IoT and edge computing *** accurate energy prediction approach is critical to provide measurement and lead optimization ***,the current energy prediction approaches lack accuracy and generalization ability due to the lack of research on the neural network structure and the excessive reliance on customized training *** paper presents a novel energy prediction model,*** treats neural networks as directed graphs and applies a bi-directional graph neural network training on a randomly generated dataset to extract structural features for energy *** has advantages over linear approaches because the bi-directional graph neural network collects structural features from each layer's parents and *** results show that NeurstrucEnergy establishes state-of-the-art results with mean absolute percentage error of 2.60%.We also evaluate NeurstrucEnergy in a randomly generated dataset,achieving the mean absolute percentage error of 4.83%over 10 typical convolutional neural networks in recent years and 7 efficient convolutional neural networks created by neural architecture *** code is available at https://***/NEUSoftGreenAI/***.

关键词： Internet of things Neural network energy prediction Graph neural networks Graph structure embedding Multi-head attention

Genome sequencing provides insights into Caprifoliaceae genome evolution and the mechanism underlying second blooming phenomenon in heptacodium miconioides

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Horticultural Plant Journal 2024年第3期10卷 897-910页

作者： Yueling Li Zhongshuai Sun zexin Jin Junmin Li Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation Taizhou UniversityTaizhouZhejiang 318000China Institute of Ecology Taizhou UniversityTaizhouZhejiang 318000China School of Life Sciences Taizhou UniversityTaizhouZhejiang 318000China

Plants of the Caprifoliaceae family are widely cultivated worldwide as ornamental plants owing to their numerous,sweet-smelling,beautiful flowers and *** miconioides Rehd.,a member of the family,is endemic to eastern China and is cultivated as a popular ornamental plant in North America and European *** has a rather novel and beautiful trait of high horticultural value,that is,its sepals persist and enlarge,turning purplish ***,we report the chromosome-level genome assembly of *** to understand its evolution and floral *** 622.28 Mb assembled genome harbored a shared whole-genome duplication with a related species,Lonicera *** genomic analysis suggested that chromosome fission events following genome duplication underlie the unusual chromosome number of these two species,as well as chromosome fission of another five chromosomes in ***,giving rise to a haploid chromosome number of 14(versus 9 in ***).In addition,based on transcriptome and chloroplast genome analysis of 17 representative species in the Caprifoliaceae,we assumed that large structural variations in the chromosomes of *** were not caused by *** in the candidate genes of the MADS-box family were detected in the *** genome,including AP1-,AP3-,and SEPexpanded,which might underlie the sepal elongation and development in this *** current findings provided a critical resource for genome evolution studies in Caprifoliaceae and it was an example of how multi-omics data can elucidate the regulation of important ornamental traits.

关键词： heptacodium miconioides Genome assembly Caprifoliaceae Chromosome fusion Sepal traits

超声振动作用下镁-钢焊缝组织演变及力学性能研究

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材料科学与工艺 2022年第4期30卷 79-85页

作者：何泽歆王大鹏周斌重庆工商职业学院智能制造与汽车学院重庆401520 四川仪表工业学校汽车工程系重庆400702

本文旨在通过引入超声振动辅助,实现镁合金和镀锌钢的可靠连接,扩大镁-钢复合构件应用范围。本文在镁合金与镀锌钢的TIG熔钎焊过程中引入超声波振动,并通过金相显微镜、扫描电镜、硬度计和拉伸机等设备对镁-钢接头微观组织和力学性能进... 详细信息

本文旨在通过引入超声振动辅助,实现镁合金和镀锌钢的可靠连接,扩大镁-钢复合构件应用范围。本文在镁合金与镀锌钢的TIG熔钎焊过程中引入超声波振动,并通过金相显微镜、扫描电镜、硬度计和拉伸机等设备对镁-钢接头微观组织和力学性能进行检测,研究超声波功率对镁合金/镀锌钢接头质量的影响。实验结果表明:超声波振动辅助焊接工艺可以有效改善镁/钢接头的焊缝成形,消除接头熔焊区域的气孔等缺陷。研究表明:在焊接过程中引入1 000 W功率进行超声振动后,接头熔焊区的平均晶粒尺寸由初始的51μm下降到23.2μm,晶粒细化效果显著;超声振动辅助焊接工艺改善了接头钎焊区反应层的形态,使钎焊区MgZn反应层厚度更均匀,并可以提高接头熔焊区的显微硬度;当超声波功率为1 000 W时,接头力学性能达到3 735 N,相比未施加超声波振动的接头(3 270 N),力学性能提高了14.2%。超声振动辅助工艺可以有效改善镁/钢焊缝的显微组织,提高接头力学性能,实现镁/钢异种金属的可靠连接。

关键词：金属材料的焊接超声波镁合金钢力学性能