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Land Use Effects on the Distribution and Speciation of Heavy Metals and Arsenic in Coastal Soils on Chongming Island in the Yangtze River Estuary, China

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Pedosphere 2016年第1期26卷 74-84页

作者： ZHENG Rong ZHAO Jiale ZHOU Xiu ma chao WANG Li GAO Xiaojiang Department of Environmental Science and Engineering Fudan University Center of Analysis and Measurement Fudan University

The reclamation of tidal fiats has been one of the important approaches to replenish the arable lands in the coastal areas; pollution status of reclaimed soils has received wide attention recently, especially for the study of heavy metals due to the relative high pollutant concentrations in wetlands. To understand the impact of land use change on heavy metal and arsenic （As） geochemistry by the reclamation of wetlands for agriculture, surface soils and soil profiles were collected from the agricultural land reclaimed in the 1990s and the intertidal flat wetland at Dongtan on Chongming Island in the Yangtze River Estuary, China. The soil samples were analyzed for total concentrations and chemical speciation of chromium （Cr）, zinc （Zn）, copper （Cu）, lead （Pb）, nickel （Ni）, cadmium （Cd） and As using inductively coupled plasma mass spectrometry （ICP-MS）. Results showed that soil properties （salinity, total organic carbon and grain-size distribution） and the concentrations of heavy metals and As in the soils differed under the different land use types. The conversion of wetland to forest had caused obvious losses of all the measured heavy metals. In paddy field and dryland with frequent cultivation, the concentrations of Cr, Zn, Cu, Ni and As were higher when compared to forest land which was disturbed rarely by human activities. Speciation analysis showed that Cr, Zn, Cu, Ni and As were predominated by the immobile residual fraction, while Pb and Cd showed relatively higher mobility. In general, metal （except Ni） and As mobility decreased in the following order： wetland 〉 dryland 〉 paddy field 〉 forest land, which suggested that the reclaimed soils had lower metal and As mobility than the intertidal fiat wetland. The results of this study contribute to a better understanding of the effects of land use on heavy metals and As in the reclaimed soils of the study area and other similar coastal areas.

关键词： chemical fraction dryland forest land intertidal flat paddy field reclaimed soils wetland

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Effects of CeO_2 on the XPS valence band spectra of coal under the combustion initialization stage at 400℃

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International Journal of Minerals,Metallurgy and materials 2013年第4期20卷 338-344页

作者： Cheng-lin Qi Jian-liang Zhang chao ma Gen-sheng Feng Zhong-ping Song State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing Shougang Research Institute of Technology

In order to get the catalytic mechanism of CeO2 on graphite and coal at 400℃, the morphologies of coal, graphite, and CeO2 before and after combustion were analyzed through X-ray photoelectron spectroscopy （XPS）. It is found that the particle size of coal is mostly between 11.727 and 64.79 μm, while the particle size of CeO2 is between 1.937 and 11.79 μm. The agglomeration of coal and CeO2 can be seen by scanning electron microscopy （SEM） after reaction. XPS results show that with the addition of CeO2, the intensity of binding energy gets stronger, but there is no energy peak transition. Comparing the character of coal with and without the addition of CeO2, it can be seen that the C C bond fractures first at 400℃, while the C-H energy-band takes electrons at the same time to be far away from the Fermi level, and the O 2s, O 2p, and C sp hybrid orbitals are all excited. Adding CeO2 can enhance the activity of the whole coal. In addition, through XPS analysis, combined with the oxygen transfer theory and the electron transfer theory, the catalytic mechanism of CeO2 for pulverized coal combustion could be obtained.

关键词： coal combustion cerium oxide valence bands catalysis binding energy X-ray photoelectron spectroscopy pulverized fuel

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Ethylenediaminetetraacetic acid-assisted synthesis of Bi2Se3 nanostructures with unique edge sites

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Nano Research 2016年第9期9卷 2707-2714页

作者： Xianli Liu Zhicheng Fang Qi Zhang Ruijie Huang Lin Lin Chunmiao Ye chao ma Hefei National Laboratory for Physical Sciences at the Microscale Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of SciencesHefei Science Center & National Synchrotron Radiation LaboratoryDepartment of Chemical PhysicsUniversity of Science and Technology of ChinaHefei 230026China

Nanomaterials with unique edge sites have received increasing attention due to their superior performance in various applications. Herein, we employed an effective ethylenediaminetetraacetic acid (EDTA)-assisted method to synthesize a series of exotic Bi2Se3nanostructures with distinct edge sites. It was found that the products changed from smooth nanoplates to half-plate-containing and crown-like nanoplates upon increasing the molar ratio of EDTA to Bi3+. Mechanistic studies indicated that, when a dislocation source and relatively high supersaturation exist, the step edges in the initially formed seeds can serve as supporting sites for the growth of epilayers, leading to the formation of half-plate-containing nanoplates. In contrast, when the dislocation source and a suitably low supersaturation are simultaneously present in the system, the dislocation-driven growth mode dominates the process, in which the step edges form at the later stage of the growth responsible for the formation of crown-like nanoplates. [Figure not available: see fulltext.] © 2016, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

关键词： Bi2Se3 edge sites ethylenediaminetetraacetic acid (EDTA) dislocation source supersaturation

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Influence of Initial Microstructure on the Strengthening Effect of Extruded Mg–8Sn–4Zn–2Al Alloys

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Acta Metallurgica Sinica(English Letters) 2018年第5期31卷 487-495页

作者： Yang Bai Wei-Li Cheng Shi-chao ma Jun Zhang Chen Guo Yao Zhang School of materials Science and Engineering Taiyuan University of Technology Shanxi Key Laboratory of Advanced magnesium-Based materials Taiyuan University of Technology Key Laboratory of Interface Science and Engineering in Advanced materials Ministry of Education Taiyuan University of Technology

The Mg–8Sn–4Zn–2Al（TZA842, in wt%） alloys with different initial microstructure（as-cast-AC and homogenization treatment-HT） subjected to hot extrusion. Also, the strengthening responses to AC and HT for the extruded TZA842 alloys were reported. The results revealed that the alloy subjected to HT shows finer grain size, more homogenous microstructure and weaker basal texture than those of counterpart subjected to AC. In addition, compared with TZA842-AC alloy, precipitates were finer and uniformly dispersed in TZA842-HT owing to the utilization of HT. Moreover, the TZA842-HT alloy showed higher yield strength of 200 MPa, ultimate tensile strength of 290 MPa and elongation（EL） of17.9% than those of TZA842-AC, which was mainly attributed to the combined effects of grain boundary strengthening,precipitation strengthening, solid solution strengthening and weak texture. Strengthening mechanism for both alloys was discussed in detail.

关键词： Mg-Sn alloy Extrusion Microstrueture Tensile property Strengthening mechanism

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Quantitative identification and prediction of mixed lithology, Bohai Sea, China

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Energy Geoscience 2024年第3期5卷 212-220页

作者： Shaopeng Wang Longtao Cui Li'an Zhang chao ma Hebing Tang Tianjin Branch of CNOOC Ltd. Tianjin 300459China

The Paleogene Shahejie Formation in the KL16 oilfield, Bohai bay, is characterized by a thinly interbedded mixed sedimentary system, with complex sedimentary facies, lithologic types and distributions. It is hard for conventional logging methods to identify the lithology therein. In order to solve the difficulty in lithologic identification of mixed sedimentary system, analyses based on graph data base using elemental capture energy spectrum log have been proposed. Due to the different composition for the various minerals, we innovatively established the molar numbers of silicon, calcium, magnesium, and aluminum as characteristic parameters for sandstone, limestone, dolomite, and mudstone, and a graph clustering analysis method was applied to identify lithology. Considering the seismic waveforms corresponding to lithologic impedance of reservoir, three seismic phases were identified by neural network clustering analysis of seismic waveform, and the seismic attributes with high sensitivity to reservoir thickness were then selected to realize the fine description of the mixed carbonate-siliciclastic reservoir. Drilling results confirmed that the sedimentary facies were accurately identified, with reservoir prediction accuracy reaching up to 80%. Under the guidance of reservoir research, the oil-in-place discovered in the oilfield were estimated to be more than 5 million tonnes. This technology provides reference for the exploration and development of oilfields of mixed sedimentary system.

关键词： Mixed carbonate-siliciclastics Waveform clustering Quantitative identification of lithology Bohai Bay Basin

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Cloning,characterization,and expression of a novel member of proteasomal subunits gene in turbot,Scophthalmus maximus

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Acta Oceanologica Sinica 2015年第1期34卷 110-118页

作者： ZHANG Bo WANG Xianli SONG Wenping ZHENG Debin ma chao XIAO Guangxia Tianjin Bohai Sea Fisheries Research Institute Bohai Sea Fisheries Research Center of Chinese Academy of Fishery Sciences Translational Center for Stem Cell Research Tongji HospitalStem Cell Research CenterTongji University School of Medicine

The proteasome is a large, polymeric protease complex responsible for the degradation of intracellular pro- teins and generation of peptides that bind to class I major histocompatibility complex （MHC） molecules. This study identified a new member of proteasomal subunits in turbots （Scophthalrnus rnaxirnus）. The full- length cDNA sequence of turbot proteasomal subunit was obtained. Sequence analysis indicated that its primary structure is highly similar to that of LMP7 from other vertebrates. The relationship between the turbot LMP7 expression and immune responses to pathogen infection was reported. Quantitative reverse transcriptase polymerase chain reaction showed that LMPTwas expressed differently in various tissues, with higher expression in the spleen, liver, muscle, and skin. The LMP7 expression was the highest at 96 h after challenge with lymphocyctis disease virus （LCDV） and at 12 h after challenge with Vibrio anguillarurn in the turbot liver, kidney, and spleen. Furthermore, the LMP7 expression distinctly increased in turbot kidney cells at 24 h after challenge with V. anguillarurn and at 96 h after challenge with LCDV. These results indicate that the turbot LMP7 protein participates in immune responses and may play a significant role in the immune process.

关键词： major histocompatibility complex (MHC) LMP7 qRT-PCR immune response turbot Vibrioanguillarum

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Federation Boosting Tree for Originator Rights Protection

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Computers, materials & Continua 2023年第2期74卷 4043-4058页

作者： Yinggang Sun Hongguo Zhang chao ma Hai Huang Dongyang Zhan Jiaxing Qu Harbin University of Science and Technology Harbin150040China School of Cyberspace Science Harbin Institute of TechnologyHarbin150001China The Ohio State University Columbus43202USA Heilongjiang Province Cyberspace Research Center Harbin150001China

The problem of data island hinders the application of big data in artificial intelligence model training,so researchers propose a federated learning *** enables model training without having to centralize all data in a central storage *** the current horizontal federated learning scheme,each participant gets the final jointly trained *** solution is proposed for scenarios where participants only provide training data in exchange for benefits,but do not care about the final jointly trained ***,this paper proposes a newboosted tree algorithm,calledRPBT(the originator Rights Protected federated Boosted Tree algorithm).Compared with the current horizontal federal learning algorithm,each participant will obtain the final jointly trained *** can guarantee that the local data of the participants will not be leaked,while the final jointly trained model cannot be *** is worth mentioning that,from the perspective of the participants,the scheme uses the batch idea to make the participants participate in the training in random ***,this scheme is more suitable for scenarios where a large number of participants are jointly ***,a small number of participants will not actually participate in the joint training ***,the proposed scheme is more *** analysis and experimental evaluations show that RPBT is secure,accurate and efficient.

关键词： Federated learning data privacy rights protection decision tree

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Earthquake-induced soft-sediment deformation structures in the Mesoproterozoic Wumishan Formation,North China,and their geologic implications

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Science China Earth Sciences 2007年第3期50卷 350-358页

作者： ZHANG ChuanHeng WU ZhengJie GAO LinZhi WANG Wei TIAN YanLin ma chao State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesBeijing 100083China Key Laboratory of Lithospheric Tectonics and Lithoprobing Technology Ministry of EducationChina University of GeosciencesBeijing 100083China School of Geosciences and Resources China University of GeosciencesBeijing 100083China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China

Soft-sediment structures are key to defining seismites. Two soft-sediment deformation horizons, bounded by undeformed carbonate strata, have been found in the Wumishan Formation in the Jumahe region, 175 km southwest of Beijing. One is in the lowest part of Wumishan Formation; and the other is in the uppermost part of Litho-member I. The soft-sediment structures in these two horizons fall into three categories: mould-and-sag structures, hydraulic shatterings and liquefaction dikes. The mould-and-sag structures are divided into two types: one developed in tidal-flat sediments, accompa-nied by many liquefaction-related structures and characterized by autochthonous post-earthquake sediments in sags, and the other type developed in deep-water environments, is not associated with liquefaction structures, and is overlain immediately by seismogenic tsunamites. The hydraulic shat-terings are composed of pockets of fluidization conglomerate, sand intrusions, and syndepositional faults. The liquefaction dikes fall into two categories: hydraulic-fracturing dikes and lateral-spreading dikes. The former are steep, planar, and pinch out upwards. The latter are snake-like and characterized by no diapir-related drag structures in surrounding rocks. Examination of the attitudes and strati-graphic positions of these structures suggests that these soft-sediment structures are seismogenic, and consequently, are seismites. Most seismites in the Wumishan Formation are developed near the former western, margin fault of Yanliao rift. This occurrence suggests that they could be related to movements on this fault. Other geological implications are discussed.

关键词： Mesoproterozoic Wumishan Formation soft-sediment structures paleo-earthquakes seismites Yanliao rift

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Encoding methods matching the 16×16 pixel CZT detector of a coded aperture gamma camera

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Nuclear Science and Techniques 2020年第9期31卷 82-89页

作者： Xiao-Lei Shen Pin Gong Xiao-Bin Tang Rui Zhang Jin-chao ma Department of Nuclear Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Nuclear Technology Application and Radiation Protection in Astronautics(Nanjing University of Aeronautics and Astronautics) Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China

With the advancements in nuclear energy,methods that can accurately obtain the spatial information of radioactive sources have become essential for nuclear energy *** aperture imaging technology is widely used because it provides two-dimensional distribution information of radioactive *** coded array is a major component of a coded aperture gamma camera,and it affects the key performance parameters of the ***,commonly used coded arrays such as uniformly redundant arrays(URAs)and modified uniformly redundant arrays(MURAs)have prime numbers of rows or columns and may lead to wastage of detector pixels.A 16×16 coded array was designed on the basis of an existing 16×16 multi-pixel position-sensitive cadmium zinc telluride *** digital signal-to-noise(SNR)ratio of the point spread function at the center of the array is ***,Monte Carlo camera models and experimental devices based on rank-13 MURA and rank-16 URA have been *** the same angular resolution,the field size of view under rank-16 URA is 1.53 times that of under rank-13 ***(Am-241,Co-57,Ir-192,Cs-137)and experiments(Co-57)are conducted to compare the imaging performance between rank-16 URA and rank-13 *** contrast-to-noise ratio of the reconstructed image of the rank-16 array is great and only slightly lower than that of rank-13 ***,as the photon energy increases,the gap becomes almost negligible.

关键词： Coded aperture imaging CZT Gamma camera Uniformly redundant arrays

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Recovery and separation of rare earth elements by molten salt electrolysis

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International Journal of Minerals,Metallurgy and materials 2021年第6期28卷 899-914页

作者： Tai-qi Yin Yun Xue Yong-de Yan Zhen-chao ma Fu-qiu ma Mi-lin Zhang Gui-ling Wang Min Qiu Yantai Research Institute&Graduate School Harbin Engineering UniversityYantai 264006China College of Science Heihe UniversityHeihe 164300China Zhongkexin Engineering Consulting(Beijing)Co. LtdBeijing 100039China

With the increasing demand of rare earth metals in functional materials,recovery of rare earth elements(REEs)from secondary resources has become important for the green economy *** salt electrolysis has the advantages of low water consumption and low hazardous waste during REE *** review systematically summarizes the separation and electroextraction of REEs on various reactive electrodes in different molten *** also highlights the relationship between the formed alloy phases and electrodeposition parameters,including applied potential,current,and ion ***,the feasibility of using LiF–NaF–KF electrolyte to recover REEs is evaluated through thermodynamic *** related to REE separation/recovery the choice of electrolyte are discussed in detail to realize the low-energy and high current efficiency of practical applications.

关键词： rare earth element molten salt reactive electrode electrochemical separation

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