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Picoplankton and virioplankton abundance and community structure in Pearl River Estuary and Daya Bay, South China

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Journal of Environmental Sciences 2015年第6期27卷 146-154页

作者： Zhixin ni Xiaoping Huang Xia zhang Key Laboratory of Tropical Marine Bio-resources and Ecology South China Sea Institute of Oceanology Chinese Academy of Sciences South China Sea Environmental Monitoring Center South China Sea Branch of the State Oceanic Administration University of Chinese Academy of Sciences

By using flow cytometry techniques, we investigated the abundance and composition of the heterotrophic prokaryotes, virioplankton and picophytoplankton community in the Pearl River Estuary and Daya Bay in the summer of 2012. We identified two subgroups of prokaryotes, high nucleic acid（HNA） and low nucleic acid（LNA）, characterized by different nucleic acid contents. HNA abundance was significantly correlated with larger phytoplankton and Synechococcus（Syn） abundance, which suggested the important role of organic substrates released from primary producers on bacterial growth. Although LNA did not show any association with environmental variables, it was a vital component of the microbial community. In contrast to previous studies, the total virioplankton concentration had a poor relationship with nutrient availability. The positive relationship between large-sized phytoplankton abundance and the V-I population confirmed that V-I was a phytoplankton-infecting viral subgroup. Although the V-II group（bacteriophages）was dominant in the virioplankton community, it was not related with prokaryotic abundance, which indicated factors other than hosts controlling V-II abundance or the uncertainty of virus-host coupling. With respect to the picophytoplankton community,our results implied that river input exerted a strong limitation to Syn distribution in the estuary, while picoeukaryotes（Euk） were numerically less abundant and showed a quite different distribution pattern from that of Syn, and hence presented ecological properties distinct from Syn in our two studied areas.

关键词： Picoplankton Virioplankton Community composition Flow cytometry

Electronic structure,bonding characteristics,and mechanical behaviors of a new family of Si-containi.g damage-tolerant MAB phases M_(5)SiB_(2)(M=IVB-VIB transition metals)

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Journal of Advanced Ceramics 2022年第10期11卷 1626-1640页

作者： Na ni Hanchao zhang Yanchun ZHOU School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China

MAB phases are layered ternary compounds with alternative stacking of transition metal boride layers and group A element *** now,most of the investigated MAB phases are concentrated on compounds with Al as the A element *** this work,the family of M_(5)SiB_(2)(M=IVB-VIB transition metals)compounds with silicon as interlayers were investigated by density functional theory(DFT)methods as potential MAB phases for high-temperature *** from the known Mo5SiB2,the electronic structure,bonding characteristics,and mechanical behaviors were systematically investigated and *** the composition of M_(5)SiB_(2) does not follow the general formula of experimentally reported(MB)_(2z)A_(x)(MB_(2))_(y)(z=1,2;x=1,2;y=0,1,2),their layered structure and anisotropic bonding characteristics are similar to other known MAB phases,which justifies their classification as new members of this material *** a result of the higher bulk modulus and lower shear modulus,Mo_(5)SiB_(2) has a Pugh’s ratio of 0.53,which is much lower than the common MAB *** was found that the stability and mechanical properties of M_(5)SiB_(2) compounds depend on their valence electron concentrations(VECs),and an optimum VEC exists as the criteria for *** hypothesized Zr and Hf containi.g compounds,i.e.,Zr_(5)SiB_(2) and Hf_(5)SiB_(2),which are more interesting in terms of high-temperature oxidation/ablation resistance,were found to be unfortunately *** cope with this problem,a new stable solid solution(Zr_(0.6)Mo_(0.4))_(5)SiB_(2) was designed based on VEC tuni.g to demonstrate a promising approach for developing new MAB phases with desirable compositions.

关键词： borides MAB phases density functional theory(DFT) thermodynamic stability electronic structure mechanical properties

Water and partial melting of Earth's mantle

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Science China Earth Sciences 2016年第4期59卷 720-730页

作者： ni HuaiWei zhang Li gUO Xuan Chinese Academy of Sciences Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space SciencesUniversity of Science and Technology of China

Water plays a crucial role in the melting of Earth's mantle. Mantle magmatisms mostly occur at plate boundaries(including subduction zones and mid-ocean ridges) and in some intraplate regions with thermal anomaly. At oceanic subduction zones, water released by the subducted slab may induce melting of the overlying mantle wedge or even the slab itself, giving rise to arc magmatism, or may evolve into a supercritical fluid. The physicochemical conditions for the formation of slab melt and supercritical fluid are still under debate. At mid-ocean ridges and intraplate hot zones, water and CO_2 cause melting of the upwelling mantle to occur at greater depths and in greater extents. Low degree melting of the mantle may occur at boundaries between Earth's internal spheres, including the lithosphere-asthenosphere boundary(LAB), the upper mantletransition zone boundary, and the transition zone-lower mantle boundary, usually attributed to contrasting water storage capacity across the boundary. The origin for the stimulating effect of water on melting lies in that water as an incompatible component has a strong tendency to be enriched in the melt(i.e., with a mineral-melt partition coefficient much smaller than unity), thereby lowering the gibbs free energy of the melt. The partitioni.g of water between melt and mantle minerals such as olivine, pyroxenes and garnet has been investigated extensively, but the effects of hydration on the density and transport properties of silicate melts require further assessments by experimental and computational approaches.

关键词： Water Mantle Partial melting Silicate melts Partition coefficient Supercritical fluid

Piston-ring and Cylinder-liner Lubrication in Internal Combustion Engines Based on Thermo-hydrodynamic

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Chinese Journal of Mechanical Engineering 2011年第6期24卷 971-975页

作者： zhang Junhong gAO Hongge ni.guangjian State Key Laboratory of Engine Tianjin UniversityTianjin 300072China Tianjin Internal Combustion Engine Research Institute Tianjin 300072China

Currently the extruded effect,roughness to the lubricant shear thinni.g,temperature changes and other factors or some combination of a single factor mainly considered in the lubrication study of piston *** the study of the energy equation,the oil viscosity-temperature properties,adsorption layer characteristics are usually not *** the theoretical research is different from the actual situation of *** lubrication of piston ring-cylinder liner system in internal combustion(IC) engines is studied here based on the theory of thermal *** unsteady and compressible hydrodynamic lubrication model with an equivalent viscosity based on shear and extruded flow factor is derived by employing the viscosity-temperature relationship,meanwhile,characteristics such as lubricating oil’s density varying with pressure and temperature,thickness of adsorbent layer and oil film’s geometry are also considered in this *** setting up the energy equation,the effect of lubricating oil’s volume expansion and viscous dissipation on temperature,the heat conduction along oil film’s thickness direction are *** difference equation is formed by using a first-order difference scheme in time scale and second-order difference scheme in space scale.A common diesel engine is introduced as an instance to predict the distribution of the minimum oil film thickness in the piston ring-cylinder liner *** results of simulation calculation show that the minimum oil film thickness will decrease especially around the top dead center when the oil’s volume expansion,viscous dissipation and heat conduction are considered,which implies that:it is essential to take the thermal flow idea into account during investigating piston ring-cylinder liner system’s lubrication.A more complete piston ring-cylinder liner lubrication theory was established according to thermal fluids from the perspective of *** is more helpful to guide the practical applicat

关键词： thermal flow piston ring-cylinder liner adsorbent layer viscosity-temperature revision

Characteristics of the Main Journal Bearings of an Engine Based on Non-linear Dynamics

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Chinese Journal of Mechanical Engineering 2009年第5期22卷 755-759页

作者： ni.guangjian zhang Junhong CHENg Xiaoming State Key Laboratory of Engine Tianjin University Tianjin 300072 China Tianjin Internal Combustion Engine Research Institute Tianjin 300072 China

Many simple nonlinear main journal bearing models have been studied theoretically, but the connection to existing engineering system has not been equally investigated. The consideration of the characteristics of engine main journal bearings may provide a prediction of the bearing load and lubrication. Due to the strong non-linear features in bearing lubrication procedure, it is difficult to predict those characteristics. A non-linear dynamic model is described for analyzing the characteristics of engine main journal bearings. Components such as crankshaft, main journals and con rods are found by applying the finite element method. Non-linear spring/dampers are introduced to imitate the constraint and supporting functions provided by the main bearing and oil film. The engine gas pressure is imposed as excitation on the model via the engine piston, con rod, etc. The bearing reaction force is calculated over one engine cycle, and meanwhile, the oil film thickness and pressure distribution are obtained based on Reynolds differential equation. It can be found that the maximum bearing reaction force always occurs when the maximum cylinder pressure arises in the cylinder adjacent to that bearing. The simulated minimum oil film thickness, which is 3 μm, demonstrates the reliability of the main journal bearings. This non-linear dynamic analysis may save computing efforts of engine main bearing design and also is of good precision and close connection to actual engine main journal bearing conditions.

关键词： non-linear dynamics engine main journal bearings

Effect of Al content on the reaction between Fe-10Mn-xAl(x=0.035wt%,0.5wt%,1wt%,and 2wt%)steel and CaO-SiO_(2)-Al_(2)O_(3)-MgO slag

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International Journal of Minerals,Metallurgy and Materials 2022年第2期29卷 256-262页

作者： Huixiang Yu Dexin Yang Jiaming zhang guangyuan Qiu ni zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

The effect of Al content(0.035 wt%,0.5 wt%,1 wt%,and 2 wt%)on the composition change of steel and slag as well as inclusion transformation of high manganese steel after it has equilibrated with Ca O-Si O_(2)-Al_(2)O_(3)-Mg O slag was studied using the method of slag/steel *** experimental results showed that as the initial content of Al increased from 0.035 wt%to 2 wt%,Al gradually replaced Mn to react with Si O_(2)in slag to avoid the loss of Mn due to the reaction;this process caused both Al_(2)O_(3)in slag and Si in steel to increase while Si O_(2)and Mn O in slag to *** addition,the type of inclusions also evolved as the initial Al content *** evolution route of inclusions was Mn O→Mn O-Al_(2)O_(3)-Mg O→Mg O→Mn O-Ca O-Al_(2)O_(3)-Mg O and Mn O-Ca O-Mg *** shape of inclusions evolved from spherical to irregular,became faceted,and finally transformed to *** average size of inclusions presented a trend that was increasing first and then *** transformation mechanism of inclusions was *** the initial content of Al increased,Mg and Ca were reduced from top slag into molten steel in sequence,which consequently caused the transformation of inclusions.

关键词： medium/high manganese steel Al content steel composition slag composition non-metallic inclusion slag/steel reaction

Spontaneous Orientation Polarization of Anisotropic Equivalent Dipoles Harnessed by Entropy Engineering for Ultra‑Thin Electromagnetic Wave Absorber

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Nano-Micro Letters 2025年第1期17卷 424-438页

作者： Honghan Wang Xinyu Xiao Shangru Zhai Chuang Xue guangping Zheng Deqing zhang Renchao Che Junye Cheng Liaoni.g Key Lab of Lignocellulose Chemistry and BioMaterials Liaoning Collaborative Innovation Center for Lignocellulosic BiorefinerySchool of Light Industry and Chemical EngineeringDalian Polytechnic UniversityDalian 116034People’s Republic of China School of Life Science and Biotechnology Dalian University of TechnologyDalian 116024People’s Republic of China Department of Mechanical Engineering Hong Kong Polytechnic UniversityHung HomKowloonHong Kong 999077People’s Republic of China School of Materials Science and Engineering Qiqihar UniversityQiqihar 161006People’s Republic of China Laboratory of Advanced Materials Shanghai Key Lab of Molecular Catalysis and Innovative MaterialsAcademy for Engineering&TechnologyFudan UniversityShanghai 200438People’s Republic of China Department of Materials Science Shenzhen MSU-BIT UniversityShenzhen 517182People’s Republic of China

The synthesis of carbon supporter/nanoscale high-entropy alloys(HEAs)electromagnetic response composites by carbothermal shock method has been identified as an advanced strategy for the collaborative competition engineering of conductive/dielectric *** migration modes within HEAs as manipulated by the electronegativity,valence electron configurations and molar proportions of constituent elements determine the steady state and efficiency of equivalent ***,enlightened by skin-like effect,a reformative carbothermal shock method using carbonized cellulose paper(CCP)as carbon supporter is used to preserve the oxygencontaini.g functional groups(O·)of carbonized cellulose fibers(CCF).Nucleation of HEAs and construction of emblematic shell-core CCF/HEAs heterointerfaces are inextricably linked to carbon metabolism induced by O·.Meanwhile,the electron migration mode of switchable electronrich sites promotes the orientation polarization of anisotropic equivalent *** virtue of the reinforcement strategy,CCP/HEAs composite prepared by 35%molar ratio of Mn element(CCP/HEAs-Mn_(2.15))achieves efficient electromagnetic wave(EMW)absorption of−51.35 dB at an ultra-thin thickness of 1.03 *** mechanisms of the resulting dielectric properties of HEAs-based EMW absorbing materials are elucidated by combini.g theoretical calculations with experimental characterizations,which provide theoretical bases and feasible strategies for the simulation and practical application of electromagnetic functional devices(e.g.,ultra-wideband bandpass filter).

关键词： High-entropy alloys Carbothermal shock Switchable electron migration modes Emblematic shell-core heterointerfaces Ultra-thin thickness

Multi-verse optimizer based parameters decision with considering tool life in dry hobbing process

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Advances in Manufacturing 2021年第2期9卷 216-234页

作者： Heng-Xin ni Chun-Ping Yan Shen-Fu ni Huan Shu Yu zhang State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqing 400030People’s Republic of China Hefei Meiya Photoelectric Technology Co.Ltd Hefei 230088People’s Republic of China

Dry hobbing has received extensive attention for its environmentally friendly processing *** to the absence of lubricants,hobbing process is highly dependent on process parameters combination since using unreasonable parameters tends to affect the machini.g ***,the consideration of tool life is frequently ignored in gear ***,to settle the above issues,a multiobjective parameters decision approach considering tool life is ***,detailed quantitative analysis between process parameters and hobbing performance,i.e.,machini.g time,production cost and tool life is ***,a multi-objective parameters decision-making model is constructed in search for optimum cutting parameters(cutting velocity v,axial feed rate f_(a))and hob parameters(hob diameter d_(0),threads z_(0)).Thirdly,a novel algorithm named multi-objective multi-verse optimizer(MOMVO)is utilized to solve the presented model.A case study is exhibited to show the feasibility and reliability of the proposed *** results reveal that(i)a balance can be achieved among machini.g time,production cost and tool life via appropriate process parameters determination;(ii)optimizing cutting parameters and hob parameters simultaneously contributes to optimal objectives;(iii)considering tool life provides usage precautions support and process parameters guidance for practical machini.g.

关键词： Process parameters Decision-making Tool life Dry hobbing Multi-objective multi-verse optimizer(MOMVO)

Dynamical analysis for hybrid virus infection system in switching environment

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Chinese Physics B 2020年第9期29卷 186-193页

作者： Dong-Xi Li ni zhang College of Data Science Taiyuan University of TechnologyTaiyuan 030024China College of Mathematics Taiyuan University of TechnologyTaiyuan 030024China

We investigate the dynamical behavior of hybrid virus infection systems with nonlytic immune response in switching environment, which is modeled as a stochastic process of telegraph noise and represented as a multi-state Markov chains. Firstly, The existence of unique positive solution and boundedness of the new hybrid system is proved. Furthermore, the sufficient conditions for extinction and persistence of virus are established. Finally, stochastic simulations are performed to test and demonstrate the conclusions. As a consequence, our work suggests that stochastic switching environment plays a crucial role in the process of virus prevention and treatment.

关键词： dynamical behavior hybrid virus infection system switching environment extinction