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Temporal and vertical distribution of microphytobenthos biomass in mangrove sediments of Zhujiang (Pearl River) Estuary

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Acta Oceanologica Sinica 2013年第4期32卷 82-88页

作者： liu weiqiu ZHANG Jielong TIAN Guanghong XU Hualin yan Xiaohua School of Life Sciences Sun Yat-sen University Management Office of Qi'ao-Dangan Provincial Nature Reserve Guangdong Neilingding-Futian National Nature Reserve

Being a primary producer, Microphytobenthos （MPB） play an important role in the benthic ecosystem of mangrove swamps. The temporal and vertical distribution of MPB biomass, expressed as chlorophyll a （Chl a）, was investigated in mangrove swamps on the Qi＇ao island and the Futian Mangrove Nature Reserve, Guangdong Province, South China. Both locations are situated in the Zhujiang （Pearl River） Estuary. For each location, bi-monthly sampling was carried out at four sites during low tide period. Except one site on the Qi＇ao Island, which was in Phragrnites australis marsh, all sites were in mangrove swamps. The Chl a concentration in surface （0-1 cm） sediment ranged from 0.2/2g/cm3 to 8.3 #g/cm3 in the Qi＇ao Island and from 2.1/zg/cm3 to 15.6/2g/cm3 in the Futian Mangrove Reserve. The peak Chl a concentration occurred in winter or early spring, while the lowest Chl a concentration, with a value of about one quarter of the peak, was observed in summer or early autumn. The vertical distribution of Chl a concentration exhibited an exponential decline with depth, which indicated a muddy sediment with high organic matter, and the slope of the curve was positively related to Chl a concentration in the surface sediment. The MPB biomass of the Qi＇ao Island was significantly lower than that of the Futian Mangrove Reserve. Our results suggest that the overlaying water quality might influence the MPB biomass in surface sediments.

关键词： microphytobenthos mangrove biomass chlorophyll a vertical distribution

Simulation and Experiment for Oxygen-enriched Combustion Engine Using Liquid Oxygen to Solidify CO2

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Chinese Journal of Mechanical Engineering 2016年第1期29卷 188-194页

作者： liu Yongfeng JIA Xiaoshe PEI Pucheng LU Yong YI Li SHI yan Beijing Research Centre of Sustainable Energy and Building Beijing University of Civil Engineering and Architecture Beijing 100044 China State Key Laboratory of Automotive Safety and Energy Tsinghua University Beijing 100084 China New Technologies and Materials Department BAIC MOTOR Corporation Ltd. Beijing Automotive Technology Center Beijing 101300 China

For capturing and recycling of CO2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle. However, due to the water spray nozzle need to be installed on the cylinder, which increases the cylinder head design difficulty and makes the combustion conditions become more complicated. In this paper, a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines. The proposed new method uses liquid oxygen to solidify part of cooled CO2 from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system. The other part of CO2 is sent to inlet system and mixed with oxygen, which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable. Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program. The effects of exhaust gas recirculation （EGR） rate are analyzed on the temperatures, the pressures and the instantaneous heat release rates when the EGR rate is more than 8%. The possibility of enclosing intake and exhaust system for engine is verified. The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO2 capture experiment is carried out. The experimental results show that when the EGR rate is 36% for the optimum EGR rate. When the liquid oxygen of 35.80-437.40 g is imported into the device and last 1-20 min, respectively, 21.50-701.30 g dry ice is obtained. This research proposes a new design method which can capture CO2 for vehicular internal combustion engine.

关键词： internal combustion Rankle cycle engine CO2 emission reduction carbon-sequestration with liquid oxygen,KIVA-3V program oxygen-enriched combustion numerical simulation experiments

The wrinkle formation in graphene on transition metal substrate:a molecular dynamics study

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International Journal of Smart and Nano Materials 2020年第3期11卷 277-287页

作者： Chao Zhao Fengning liu Xiao Kong Tianying yan Feng Ding School of Materials Science and Engineering Ulsan National Institute of Science and Technology(UNIST)UlsanRepublic of Korea Center for Multidimensional Carbon Materials Institute for Basic ScienceUlsanRepublic of Korea Institute of New Energy Material Chemistry School of Materials Science and EngineeringNational Institute for Advanced MaterialsNankai UniversityTianjinP.R.China

To explore the mechanism of the wrinkle formation in graphene on transition metal substrate,a molecular dynamics(MD)simulation package that allows us to simulate systems of millions of atoms was *** the MD simulation,we reveal the detailed kinetics of wrinkles formation on a Cu substrate under compressive strain,from nucleation to one-dimensional propagation and then the splitting of a large wrinkle to a few smaller ones,which is in good conformity with experimental *** study reveals that both friction and the adhesion between graphene and Cu substrate are critical for the wrinkle formation and wrinkles can be easily formed with a lower frictional force and/or a smaller ***,we have shown that impurities in graphene or substrates can greatly facilitate the nucleation of *** systematic exploration of the wrinkle formation in graphene on a substrate is expected to facilitate the experimental designs for the controllable synthesis of high-quality graphene.

关键词： Graphene wrinkles molecular dynamic simulation chemical vapor deposition

Stereo vision based SLAM using Rao-Blackwellised particle filter

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第4期9卷 500-509页

作者： Er-yong WU Gong-yan LI Zhi-yu XIANG Ji-lin liu Department of lnformation Science and Electrical Engineering Zhejiang University Hangzhou 310027 China National Laboratory of Pattern Recognition Institute of Automation CAS Beijing 100080 China

We present an algorithm which can realize mobile robot in unknown outdoor environments, which 3D stereo vision simultaneous localization and mapping （SLAM） for means the 6-DOF motion and a sparse but persistent map of natural landmarks be constructed online only with a stereo camera. In mobile robotics research, we extend FastSLAM 2.0 like stereo vision SLAM with ＂pure vision＂ domain to outdoor environments. Unlike popular stochastic motion model used in conventional monocular vision SLAM, we utilize the ideas of structure from motion （SFM） for initial motion estimation, which is more suitable for the robot moving in large-scale outdoor, and textured environments. SIFT features are used as natural landmarks, and its 3D positions are constructed directly through triangulation. Considering the computational complexity and memory consumption, Bkd-tree and Best-Bin-First （BBF） search strategy are utilized for SIFT feature descriptor matching. Results show high accuracy of our algorithm, even in the circumstance of large translation and large rotation movements.

关键词： Robot Vision based SLAM SIFT Feature management

Early Permian Sunidyouqi suprasubduction-zone ophiolites in the central Solonker suture zone(Inner Mongolia, China)

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Geoscience Frontiers 2019年第3期10卷 1101-1111页

作者： Guo Xu Huichuan liu Yinglei Li Zhan Xu yan Xie School of Earth Sciences China University of Geosciences Inner Mongolia Key Laboratory of Magmatic Mineralization and Ore-Prospecting Geological Survey Institute of Inner Mongolia School of Earth Science and Geological Engineering Sun Yat-Sen University

Different final closing ages have been proposed for the evolution of the Paleo-Asian Ocean(PAO),including Late Silurian, pre-Late Devonian, Early Permian, Late-Permian and Late Permian-Early *** represent fragments of ancient oceanic crust and play an important role in identifying the suture zone and unveiling the evolutionary history of fossil oceans. Our detailed geological, geochemical and geochronological investigations argue for the existence of Early Permian(297 Ma) SSZ type ophiolites in the Sunidyouqi area of central Inner Mongolia, China. The gabbros and basalts show LREE depleted REE patterns and left-leaning primitive mantle-normalized spider diagrams with variable negative Nb-Ta anomalies(Nb~*= 0.24-1.28 and 0.29-0.55, respectively). The Sunidyouqi ophiolites were generated in a mature back-arc basin. The Sunidyouqi ophiolites share the same petrological,geochemical and geochronological characteristics with the other ophiolites along the Solonker suture zone, delineating a Late Paleozoic ocean and arc-trench system. This Late Paleozoic ocean and arc-trench system coincides with a Permian paleobiogeographical boundary, i.e. the boundary between the northern cold climate(Boreal faunal-Angaraland floral realm), and a southern warm climate(Tethys faunal-Cathaysian floral realm). A tectonic scenario was proposed at last for the closure of the SE PAO involving(1) Late Ordovician to Middle Permian continuous southward subduction beneath the northern margin of North China;(2) Carboniferous to Middle Permian continuous northward subduction the forming the Northern Accretionary Orogen;(3) Late Permian final closure of the SE PAO.

关键词： Paieo-Asian Ocean Solonker North China Craton Ophiolite SSZ

Over-activation of TLR5 signaling by high-dose flagellin induces liver injury in mice

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Cellular & Molecular Immunology 2015年第6期12卷 729-742页

作者： yang Xiao Fang liu Jingyi yang Maohua Zhong Ejuan Zhang Yaoming Li Dihan Zhou Yuan Cao wei Li Jie Yu Yi yang Huimin yan Mucosal immunity Research Group State Key Laboratory of Virology Wuhan institute of Virology Chinese Academy of Sciences Wuhan China

Flagellin is a potent activator of a broad range of cell types that are involved in innate and adaptive immunity. Therefore, it is a good adjuvant candidate for vaccines, and it might function as a biological protectant against both major acute radiation syndrome during cancer radiotherapy and a mitigator of radiation emergencies. However, accumulating evidence has implicated flagellin in the occurrence of some inflammatory diseases, such as acute lung inflammation, cardiovascular collapse and inflammatory bowel disease. The aim of this study was to elucidate whether only flagellin-TLR5 signaling activation plays a role in the pathophysiology of liver or whether some other flagellin activity also contributes to liver injury either via bacterial infections or during clinical applications. Recombinant flagellin proteins with or without TLR5-stimulating activity were used to evaluate the role of flagellin-TLR5 signaling in liver injury in wild-type and TLR5 KO mice. Gross lesions and large areas of hepatocellular necrosis were observed in liver tissue 12 h after the intraperitoneal administration of 100 or 200 pg flagellin （FliC） in a dose-and time-dependent manner in wild-type mice, but not in TLR5 KO mice. Deletion of the N-terminal or TLR5 binding domain of flagellin inhibited flagellin-induced inflammatory responses and the subsequent acute liver function abnormality and damage. These data confirmed that flagellin is an essential determinant of liver injury and demonstrated that the over-activation of TLR5 signaling by high-dose flagellin caused acute inflammatory responses, neutrophil accumulation and oxidative stress in the liver, which contributes to the progression and severity of flagellin-induced liver injury.

关键词： flagellin liver injury pathological effect TLR5

Droplet Motion and Phase Change Model with Two-Way Coupling

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Journal of Thermal Science 2019年第4期28卷 826-833页

作者： ZHAO Fulong liu Qianfeng yan Xiao BO Hanliang ZENG Chen TAN Sichao College of Nuclear Science and Technology Harbin Engineering UniversityHarbin 150001China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China

The droplet interacts intensively with surrounding gas when moving and evaporating in the gas,of which the mutual effects of the gas and the evaporating droplet need to be taken into *** the typical droplet model,the gas parameters are usually considered as that at infinity and the local parameter variation surrounding the droplet is neglected,consequently leading to some *** research tries to develop a new moving droplet phase change model with two-phase coupling which characterizes the local parameter variation of gas phase surrounding the evaporating ***,the interaction mechanism of two phases is presented based on the droplet evaporation ***,the droplet motion and phase change model is developed through the theoretical ***,the analysis of the evaporation characteristics of the injected droplets in the hot air is conducted to simulate the operation process of the containment spray system in the nuclear power *** numerical simulation indicates the refined droplet model is more capable for precise prediction of the situations with large quantities of evaporating droplets and with intensive interactions between two phases.

关键词： droplet evaporate heat and mass transfer two-way coupling local parameter

Preparation and electrochemical performance of double perovskite La_2CoMnO_6 nanofibers

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International Journal of Minerals,Metallurgy and Materials 2018年第8期25卷 950-956页

作者： Jie Fu Heng-yan Zhao Jie-run Wang Yu Shen Ming liu College of Environmental and Chemical Engineering Dalian Jiaotong University

Through electrospinning,La_2Co Mn O_6 nanofibers were prepared from a polyvinylpyrrolidone/lanthanum nitrate–cobalt acetate–manganese acetate(PVP/LCM)precursor and were used as electrode *** morphologies and structures of the samples were characterized by field-emission scanning electron microscopy(FE-SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),and Brunauer-Emmett-Teller(BET)specific surface area *** results show that the prepared La_2Co Mn O_6 nanofibers are stable,one-dimensional structures formed from interconnected La_2Co Mn O_(6 )nanoparticles with a diamond-like crystal *** specific surface area of the fibers is 79.407 m^2·g^(-1).Electrochemical performance tests with a three-electrode system reveal the specific capacitance of the La_2Co Mn O_6 nanofibers as 109.7 F·g^(-1) at a current density of 0.5 A·g^(-1).After 1000 charge-discharge cycles at a current density of 1 A·g^(-1),the specific capacitance maintains 90.9%of its initial value,demonstrating a promising performance of the constraint capacitance and good cyclic stability.

关键词： electrospinning double perovskite super capacitor electrode materials

High performance CuO-CeO_2 catalysts for selective oxidation of CO in excess hydrogen:Effect of hydrothermal preparation conditions

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Journal of Natural Gas Chemistry 2009年第3期18卷 346-353页

作者： Pengfei Zhu Jing Li Qinqin Huang Siming yan Mei liu Renxian Zhou Institute of Catalysis Zhejiang University Hangzhou 310028 Zhejiang China School of Chemistry and Chemical Engineering Southwest Petroleum University Chengdu 610500 Sichuan China

High performance CuO-CeO2 catalysts for selective oxidation of CO in excess hydrogen were prepared by a hydrothermal method under different preparation conditions and evaluated for catalytic activities and selectivities. By changing the ^nCTAB/^nCe ratio and hydrothermal aging time, the catalytic activity of the CuO-CeO2 catalysts increased and the operating temperature window, in which the CO conversion was higher than 99%, was widened. XRD results showed no peaks of CuOx species and Cu-Ce-O solid solution were observed. On the other hand, Cu＋ species in the CuO-CeO2 catalysts, which was associated with a strong interaction between copper oxide clusters and cerium oxide and could be favorable for improving the selective oxidation performance of CO in excess H2, were detected by H2-TPR and XPS techniques.

关键词： selective oxidation CO excess hydrogen CuO-CeO2 catalyst hydrothermal preparation condition