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In vitro corrosion of Mg-6Zn-IMn-4Sn-1.5Nd/0.5Y alloys

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Frontiers of Materials Science 2014年第3期8卷 230-243页

作者： Rong-Chang zeng Lei WANG Ding-Fei ZHANG Hong-Zhi CUI En-Hou HAN College of Materials Science and Engineering Shandong University of Science and Technology Qingdao 266590 China College of Materials Science and Engineering Chongqing University Chongqing 400044 China National Engineering Center for Corrosion Control Institute of Metals Research Chinese Academy of Sciences Shenyang 110016 China

The microstructure evaluation, surface morphology, chemical compositions and phase analysis of the biomedical Mg-6Zn-IMn-4Sn-1.5Nd/0.5Y （ZMT614- 1.5Nd/0.5Y） alloys were investigated by means of optical microscopy, EPMA, X-ray EDS, XRD and FTIR. The corrosion behavior was evaluated using weight-loss measurement, hydrogen evolution, electrochemical and pH measurements, The results demonstrate that the microstructure for both ZMT614-1,5Nd alloy and ZMT614-0.5Y alloy is characterized by α-Mg and intermetallic compounds, most of which are distributed along the grain boundaries. These second phases contain Mg2Zn, Mg2Zn11, Mg2Sn and single metal Mn, together with Mg12Nd phase for the ZMT614-1.5Nd alloy, and with Mg24Y5 phase for the ZMT614-0.5Y alloy. Honeycomb-like corrosion product layers form. The corrosion resistance of the ZMT614-0.5Y alloy is higher than that of the ZMT614-1.5Nd alloy, which is ascribed to the addition of the element Y into the alloy delaying the corrosion initiation in comparison to that of Nd element in the alloy.

关键词： magnesium alloy yttrium neodymium corrosion biomaterial

Geochemical and Sr-Nd-Pb isotopic compositions of volcanic rocks from the Iheya Ridge,the middle Okinawa Trough：implications for petrogenesis and a mantle source

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Acta Oceanologica Sinica 2018年第1期37卷 73-88页

作者： LI Xiaohui zeng Zhigang CHEN Shuai MA Yao YANG Huixin ZHANG Yuxiang CHEN Zuxing Key Laboratory of Marine Geology and Environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China University of Chinese Academy of Sciences Beijing 100049 China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology Qingdao 266071 China

As an active back-arc basin, the Okinawa Trough is located in the southeastern region of the East China Sea shelf and is strongly influenced by the subduction of the Philippine Sea Plate. Major element, trace element and Sr-NdPb isotopic composition data are presented for volcanic rocks from the Iheya Ridge（IR）, the middle Okinawa Trough. The IR rocks record large variations in major elements and range from basalts to rhyolites. Similar trace element distribution characteristics together with small variations in ^87Sr/^86Sr（0.703 862–0.704 884）, ^144Nd/^143Nd（0.512 763–0.512 880） and Pb isotopic ratios, demonstrate that the IR rocks are derived from a similar magma source. The fractional crystallization of olivine, clinopyroxene, plagioclase, and amphibole, as well as accessory minerals, can reasonably explain the compositional variations of these IR rocks. The simulations suggest that approximately 60% and 75% fractionation of an evolved basaltic magma can produce trace element compositions similar to those of the intermediate rocks and acid rocks, respectively. The analysis of their Sr-Nd-Pb isotopic content ratios suggest that the source of the rocks from the IR is close to the depleted mantle（DM） but extends to the enriched mantle（EMII）, indicating that the mantle source of these rocks is a mixture between the DM and EMII end members. The simulations show that the source of the IR volcanic rocks can be best interpreted as the result of the mixing of approximately 0.8%–2.0% subduction sediment components and 98.0%–99.2% mantlederived melts.

关键词： basic to intermediate-acid rocks fractional crystallization subduction sediment components Iheya Ridge Okinawa Trough

Origin of Cu in the PACMANUS hydrothermal field from the eastern Manus back-arc basin: evidence from mass balance modeling

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Acta Oceanologica Sinica 2019年第9期38卷 59-70页

作者： Yao Ma Xiaoyuan Wang Shuai Chen Xuebo Yin Bowen Zhu Kun Guo Zhigang zeng Key Laboratory of Marine Geology and Environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Laboratory for Marine Mineral Resources Pilot National Laboratory for Marine Science and Technology (Qingdao) Qingdao 266071 China University of Chinese Academy of Sciences Beijing 100049 China Ocean Science Isotope and Geochronology Center Pilot National Laboratory for Marine Science and Technology (Qingdao) Qingdao 266071 China

Hydrothermal precipitates associated with active vents in the eastern Manus Basin, an actively opening back-arc basin in the Bismarck Sea, Papua New Guinea, are among the most Cu-rich on the modern seafloor. The volcanic rocks associated with this mineralization may be insufficiently enriched in Cu to account for the Cu content of the sulfides by simple leaching. The PACMANUS hydrothermal field lies in the eastern portion of the eastern Manus Basin. Mass balance modeling of the PACMANUS hydrothermal system indicates that simple leaching of a stationary reaction zone (0.144 km^3) by hydrothermal fluids cannot yield the Cu found in associated sulfide deposits because unacceptably high leaching, transportation and precipitation efficiencies are required to derive the Cu in sulfides by leaching processes. With 100% leaching, transport and precipitating efficiency, 0.166 km^3 of volcanic rocks would need to be leached to account for the Cu budget of hydrothermal sulfide deposits. The key requirement for forming metal-rich magmatic fluids is a large amount of metals available to enter the exsolved vapor phase. Magmas generated in the eastern Manus Basin inherently have high fO2 because of metasomatism of the mantle source by oxidized materials from the subducted slab, leading to copper enrichment in the magma chamber. Moreover, the presence of Cu in gas-rich melt inclusi on bubbles in Pual Ridge andesite is evidence that degassing and partitioning of Cu into the magmatic volatile phase has occurred in the eastern Manus Basin. Numerical mass balance modeling indicates that approximately 0.236 Mt Cu was potentially transferred to the hydrothermal system per cubic kilometer magma. Magmatic degassing seems to play a more significant role than leaching.

关键词： back-arc basin mass balance model PACMANUS hydrothermal field source of Cu

Smectite formation in metalliferous sediments near the East Pacific Rise at 13°N

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Acta Oceanologica Sinica 2018年第9期37卷 67-81页

作者： RONG Kunbo zeng Zhigang YIN Xuebo CHEN Shuai WANG Xiaoyuan QI Haiyan MA Yao Seafloor Hydrothermal Activity Laboratory of the Key Laboratory of Marine Geology and Environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology Qingdao 266071 China University of Chinese Academy of Sciences Beijing 100049 China

A 43 cm long E271 sediment core collected near the East Pacific Rise（EPR） at 13°N were studied to investigate the origin of smectite for understanding better the geochemical behavior of hydrothermal material after deposition.E271 sediments are typical metalliferous sediments. After removal of organic matter, carbonate, biogenic opal,and Fe-Mn oxide by a series of chemical procedures, clay minerals（〈2 μm） were investigated by X-ray diffraction,chemical analysis and Si isotope analysis. Due to the influence of seafloor hydrothermal activity and close to continent, the sources of clay minerals are complex. Illite, chlorite and kaolinite are suggested to be transported from either North or Central America by rivers or winds, but smectite is authigenic. It is enriched in iron, and its contents are highest in clay minerals. Data show that smectite is most likely formed by the reaction of hydrothermal Fe-oxyhydroxide with silica and seawater in metalliferous sediments. The Si that participates in this reaction may be derived from siliceous microfossils（diatoms or radiolarians）, hydrothermal fluids, or detrital mineral phases. And their δ30 Si values are higher than those of authigenic smectites, which implies that a Si isotope fractionation occurs during the formation because of the selective absorption of light Si isotopes onto Feoxyhydroxides. Sm/Fe mass ratios（a proxy for overall REE/Fe ratio） in E271 clay minerals are lower than those in metalliferous sediments, as well as distal hydrothermal plume particles and terrigenous clay minerals. This result suggests that some REE are lost during the smectite formation, perhaps because their large ionic radii of REE scavenged by Fe-oxyhydroxides preclude substitution in either tetrahedral or octahedral lattice sites of this mineral structure, which decreases the value of metalliferous sediments as a potential resource for REE.

关键词： metalliferous sediments smectite formation REE silicon isotope

Nondeterministic Probabilistic Petri Net -- A New Method to Study Qualitative and Quantitative Behaviors of System

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Journal of Computer Science & Technology 2013年第1期28卷 203-216页

作者： Yang Liu Huai-Kou Miao Hong-Wei zeng Yan Ma Pan Liu School of Computer Engineering and Science Shanghai University Shanghai 200072 China School of Information Science and Technology Taishan University Taian 271021 China State Key Laboratory of Novel Software Technology Nanjing University Nanjing 210093 China

There are many variants of Petri net at present, and some of them can be used to model system with both function and performance specification, such as stochastic Petri net, generalized stochastic Petri net and probabilistic Petri net. In this paper, we utilize extended Petri net to address the issue of modeling and verifying system with probability and nondeterminism besides function aspects. Using probabilistic Petri net as reference, we propose a new mixed model NPPN （Nondeterministic Probabilistic Petri Net） system, which can model and verify systems with qualitative and quantitative behaviours. Then we develop a kind of process algebra for NPPN system to interpret its algebraic semantics, and an action- based PCTL （Probabilistic Computation Tree Logic） to interpret its logical semantics. Afterwards we present the rules for compositional operation of NPPN system based on NPPN system process algebra, and the model checking algorithm based on the action-based PCTL. In order to put the NPPN system into practice, we develop a friendly and visual tool for modeling, analyzing, simulating, and verifying NPPN system using action-based PCTL. The usefulness and effectiveness of the NPPN system are illustrated by modeling and model checking an elaborate model of travel arrangements workflow.

关键词： nondeterminism probabilistic Petri net model checking action-based probabilistic computation tree logic

Self-Assembled Silane Film and Silver Nanoparticles Coating on Magnesium Alloys for Corrosion Resistance and Antibacterial Applications

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Acta Metallurgica Sinica(English Letters) 2013年第6期26卷 681-686页

作者： Rongchang zeng Lijun LIU Shuoqi LI Yuhong ZOU Fen ZHANG Yanan YANG Hongzhi CUI En-hou HAN College of Material Science and Engineering Shandong University of Science and Technology College of Chemical and Environmental Engineering Shandong University of Science and Technology State Key laboratory for Corrosion and Protection Institute of Metals ResearchChinese Academy of Sciences

Contamination resulting from microbial adhesion on magnesium alloys is very common in many applications. Self-assembly technology was employed to prepare an antibacterial composite coating by fixing silver nanoparticles （AgNPs） onto the surface of magnesium alloys. The AgNPs were immobilized on the surface of 3-aminopropyltrimethoxysilane （APTMS）-modified magnesium alloy AZ31 （APTMS/Mg） through electrosta- tic inter-attraction between partially protonated amino groups and negatively charged citrate-capped AgNPs, resulting in the AgNPs attached APTMS/Mg （AgNPs/APTMS/Mg） substrate. The prepared Ag colloid and functionalized AZ31 alloy were characterized by ultraviolet-visible （UV-vis） spectroscopy, Fourier transform infrared （FTIR） spectroscopy, scanning electron microscopy （SEM）, and electrochemical methods. Finally, the bactericidal activity of AgNPs/APTMS/Mg substrate against Escherichia coli was assessed by the inhibition zone. The results demonstrated that Si-O-Si covalent bonds existed on the substrate with the formation of inorganic Si-O-Mg bonds. AgNPs were immobilized and well-dispersed, forming a uniform submonolayer on the silane film in two dimensions. The AgNPs/APTMS-pretreated AZ31 alloys exhibited better corrosion resistance and excellent antibacterial performance.

关键词： Magnesium alloy Nanoparticles Self-assembly Corrosion Antibacterial effect

Constructing subtle grain boundaries on Au sheets for enhanced CO2 photoreduction

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Science China Chemistry 2020年第12期63卷 1705-1710页

作者： Xu Li Tingting Zheng Lan Zhang Songtao Zhao Yinuo Chen Miaojin Wei Chunyan Shang Jun Bao Jie zeng Hefei National Laboratory for Physical Sciences at the Microscale National Synchrotron Radiation LaboratoryCAS Key Laboratory of Strongly-Coupled Quantum Matter PhysicsKey Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education InstitutesDepartment of Chemical PhysicsUniversity of Science and Technology of ChinaHefei 230026China College of Chemistry and Molecular Engineering Qingdao University of Science and TechnologyQingdao 266042China

Photocatalytic reduction of CO2 into value-added products is a promising strategy for mitigating environmental and energy problems ***,we developed Au sheets with subtle grain boundaries on ultrathin Ni(OH)2 nanosheets as efficient photocatalysts for CO2 *** to mechanistic studies,grain boundaries on the Au sheets served as electron trapping sites which enabled the optimization of electron-hole ***,grain boundaries perturbed electron distribution,which assisted in stabilizing CO2^δ- and HCOO^* *** a result,the unique hybrid structure achieved a high rate of 75.2μmol g^-1h^-1 for CO2 *** work demonstrates the importance of defect engineering in designing active photocatalysts and also provides insight into development of related photo-energy conversion schemes.

关键词： Au sheet grain boundary Ni(OH)2 nanosheet CO2 photoreduction

Mechanical and corrosion properties of Al/Ti film on magnesium alloy AZ31B

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Frontiers of Materials Science 2015年第1期9卷 66-76页

作者： Rong-Chang zeng KeJIANG Shuo-Qi LI Fen ZHANG Hong-Zhi CUI En-Hou HAN College of Materials Science and Engineering Shandong University of Science and Technology Qingdao 266590 China State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology Shandong University of Science and Technology Qingdao 266590 China Institute of Metals Research Chinese Academy of Sciences Shenyang 110016 China

Preparation of titanium film on magnesium substrate faces a challenge due to non-Fickian inter-diffusion between titanium and magnesium. Aluminum can build a bridge between titanium and magnesium. Al/Ti duplex coatings were deposited on magnesium alloy AZ31B using magnetron sputtering （MS）. The low temperature diffusion bonding behavior of the MglAl/Ti coating was investigated through SEM and its affiliated EDS. The phase structure and critical load of the coatings were examined by means of XRD and scratch tests, respectively, The results demonstrated that the bonding strength was significantly improved after a post heat treatment （HT） at a temperature of 210℃. The diffusion mechanism of the interfaces of MglAI and Al/Ti in the coating was discussed based on the analysis of formation energy of vacancies and diffusion rates. The Al/Ti dual layer enhanced the corrosion resistance of the alloy. And the HT process further increased the corrosion resistance of the coated alloy. This result implies that a post HTat a lower temperature after MS is an effective approach to enhance the bonding strength and corrosion resistance of the Al/Ti film on Mg alloys.

关键词： magnesium alloy aluminum/titanium coating magnetron sputtering (MS) diffusion bonding strength

Mineralogy,geochemistry,and sulfur isotope characteristics of sediment-hosted hydrothermal sulfide minerals from the southern Okinawa Trough

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Acta Oceanologica Sinica 2021年第10期40卷 129-143页

作者： Yamin Yang Zhigang zeng Xuebo Yin Xiaoyuan Wang Shuai Chen Haiyan Qi Zuxing Chen Bowen Zhu Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laboratory for Marine Mineral Resources Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266071China University of Chinese Academy of Sciences Beijing 100049China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

Studies of the mineralogy and sulfur isotope composition of sediment-hosted hydrothermal sulfide minerals in cores are important for understanding the seafloor mineralization environment and material source and reconstructing the hydrothermal ***,the source of ore-forming materials and the history of hydrothermal activity in the southern Okinawa Trough(SOT)remain ***,the mineralogy and sulfur isotope characteristics of sulfides from gravity core HOBAB4-S2,collected between the Yonaguni Knoll IV hydrothermal field(HF)and the Tangyin HF,was *** in Zn(up to 321×10^(-6)),Cu(up to73.7×10^(-6)),and Pb(up to 160×10^(-6))and the presence of pyrite,galena,pyrrhotite and minor sphalerite and chalcopyrite provide evidence for the input of hydrothermal materials into the *** pyrite morphologies include disseminated cubic,pentagonal dodecahedron,and framboidal *** for minor framboidal pyrite,euhedral pyrite from core HOBAB4-S2 is mainly of hydrothermal origin with Co/Ni ratios>1 and S/Fe atomic ratios<2 in the Cu-Zn-Pb-rich *** occurrences of hexagonal pyrrhotite,high-Co(up to0.17%)pyrite and high-Fe sphalerite indicate that the hydrothermal precipitates formed at medium-high temperatures and low-sulfur fugacity(f S_(2))*** δ^(34) S values of sulfides(0.21‰–3.45‰)with low-f S_(2) mineral assemblages(e.g.,pyrrhotite±high-Fe sphalerite)in the core are significantly lower than those of magmatic rocks and seawater,indicating possible incorporation of previously formed biogenic sulfur in the *** with the age model of the core,it is suggested that hydrothermal activity likely began in the Tangyin HF before AD 1445–1483 and that at least three active episodes may have occurred since then.

关键词： mineralogy sulfur isotopes sediment-hosted hydrothermal sulfides southern Okinawa Trough