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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第10期11卷 761-765页

作者： Dan YE De-chang JIA Zhi-hua YANG Zhen-lin sun peng-fei ZHANG Institute for Advanced Ceramics Harbin Institute of Technology Harbin 150001 China

Amorphous SiBCNAl powders were prepared via a mechanical alloying (MA) technique using crystalline silicon (Si), hexagonal boron nitride (h-BN), graphite (C), and aluminum (Al) as starting materials. SiBCNAl powders were consolidated by a hot pressing (HP) technique at 1800 °C under a pressure of 30 MPa in argon and nitrogen. The sintering atmosphere had a great influence on the microstructures and mechanical properties of the ceramics. The two ceramics had different phase compositions and fracture surface morphologies. For the ceramics sintered in argon, flexural strength, fracture toughness, elastic modulus and Vickers hardness were 421.90 MPa, 3.40 MPa·m1/2, 174.10 GPa, and 12.74 GPa, respectively. For the ceramics sintered in nitrogen, the mechanical properties increased, except for the Vickers hardness, and the values of the above properties were 526.80 MPa, 5.25 MPa·m1/2, 222.10 GPa, and 11.63 GPa, respectively.

关键词： SiBCNAl ceramics Hot pressing (HP) Mechanical properties Microstructure Mechanical alloying (MA)

Phase behavior of heavy oil-solvent mixture systems under reservoir conditions

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Petroleum Science 2020年第6期17卷 1683-1698页

作者： Xiao-fei sun Zhao-Yao Song Lin-Feng Cai Yan-Yu Zhang peng Li School of Petroleum Engineering China University of Petroleum(East China)Qingdao 266580ShandongPeople’s Republic of China Nanjing Air Fuel Co. Ltd.Nanjing 211113JiangsuPeople’s Republic of China

A novel experimental procedure was proposed to investigate the phase behavior of a solvent mixture(SM)(64 mol%CH4,8 mol%CO2,and 28 mol%C3 H8)with heavy ***,a theoretical methodology was employed to estimate the phase behavior of the heavy oil-solvent mixture(HO-SM)systems with various mole fractions of *** experimental results show that as the mole fraction of SM increases,the saturation pressures and swelling factors of the HO-SM systems considerably increase,and the viscosities and densities of the HO-SM systems *** heavy oil is upgraded in situ via asphaltene precipitation and SM ***,the solvent-enriched oil phase at the top layer of reservoirs can easily be produced from the *** aforementioned results indicate that the SM has promising application potential for enhanced heavy oil recovery via solvent-based *** theoretical methodology can accurately predict the saturation pressures,swelling factors,and densities of HO-SM systems with various mole fractions of SM,with average error percentages of1.77%for saturation pressures,0.07%for swelling factors,and 0.07%for densities.

关键词： Heavy oil Solvent mixture PR-EOS Phase behavior Pressure-volume-temperature(PVT)

Spatial-temporal dynamics of alpine grassland coverage and its response to climate warming in *** Nature Preserve during 2000-2019

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Journal of Mountain Science 2022年第8期19卷 2297-2311页

作者： MA fei peng Pei-hao College of Earth Sciences Chengdu University of TechnologyChengdu 610059China

The Qinghai-Tibet Plateau(QTP)has the largest and highest alpine grassland ecosystem in the world,which is considered to be the most sensitive and vulnerable ecosystem to climate *** dynamic changes and driving mechanism have always been widely *** Qomolangma National Nature Preserve(QNNP),with the largest altitude difference in the world,was selected as the study area to analyse the spatial-temporal dynamics of grassland coverage and the different characteristics of elevation gradients at the southern slope(SS)and northern slope(NS)with MODIS MOD13Q1 NDVI and MOD11A2 land surface temperature data from 2000to 2019 using the Mann-Kendall trend test and Theil-Sen slope ***,the response mechanism of grassland coverage to climate warming is *** results revealed that from 2000 to 2019,the grassland coverage change in the study area is mainly *** increased area proportion of grassland coverage on the southern slope is significantly higher than that on the northern slope,and the decreased area proportion of grassland coverage on the northern slope is significantly greater than that on the southern *** change characteristics of grassland coverage in the QNNP exhibit an obvious elevation gradient;the higher the elevation,the greater the increased area proportion of grassland coverage,particularly on the *** land surface temperature can be used as a proxy for analysing the temporal and spatial variation trends of air temperature in the *** the increase of the altitude,the land surface temperature rise rate on both the southern slope and northern slope exhibited an increasing trend,and the sensitivity of grassland coverage to temperature rise was higher on the northern *** water condition was the decisive factor for the horizontal and vertical spatial heterogeneity of the dynamic change of grassland coverage,and the melting of glaciers and thawing of permafrost were important sources of water for grassland gro

关键词： Alpine grassland Global warming Vegetation dynamic Elevation gradient Qomolangma

A multi-model assessment of climate change damage in China and the world

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Advances in Climate Change Research 2022年第3期13卷 385-396页

作者： Tian-peng WANG fei TENG Institute of Energy Environment and EconomyTsinghua UniversityBeijing 100084China

Quantifying climate damage is essential to informing rational climate policies,but only a few studies have systematically compared the climate damage estimates made by different models,especially for *** this study,we used three widely applied integrated assessment models-FUND,RICE,and PAGE-to estimate the damage under coupled shared socioeconomic pathways and representative concentration pathways(RCPs).Results show that the costs of climate damage constitute approximately 1.5%and 0.7%of China's GDP and global GDP per 1℃ temperature rise on average,*** can reduce climate risk by lowering the average estimate and worst-case effects of climate *** with business-as-usual emissions(RCP8.5),the 2℃ target will reduce the average estimate of climate damage for China and the world by 93%and 87%,respectively,and by 80%and 84%,respectively,in the worst-case *** analysis of climate damage highlights the inconsistency of sector scope and significant parameter uncertainties in damage modules,requiring further improvement to integrate subfield research advances,particularly for damage related to rising sea levels and cooling energy demand.

关键词： Integrated assessment models Climate damage Shared socioeconomic pathways Representative concentration pathways China

SpyStapler-mediated assembly of nanoparticle vaccines

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Nano Research 2023年第2期16卷 2821-2828页

作者： Songzi Kou Weitao Chen Chenbo sun fei sun Biomedical Research Institute Shenzhen Peking University-The Hong Kong University of Science and Technology Medical CenterShenzhen 518036China Greater Bay Biomedical Innocenter Shenzhen Bay LaboratoryShenzhen 518132China Department of Chemical and Biological Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina

The COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has wreaked havoc around the globe,with no end in *** rapid emergence of viral mutants,marked by rapid transmission and effective immune evasion,has also posed unprecedented challenges for vaccine development,not least in its speed,mass production,and *** we report a versatile“plug-and-display”strategy for creating protein vaccines,including those against malaria parasites and SARS-CoV-2,through the combined use of the intrinsically disordered protein ligase SpyStapler and computationally designed viral-like *** resulting protein nanoparticles harboring multiple antigens induce potent neutralizing antibody responses in mice,substantially stronger than those induced by the corresponding free *** modular vaccine design enabled by SpyStapler furnishes us with a new weapon for combatting infectious diseases.

关键词： subunit vaccine SpyTag SARS-CoV-2 malaria

Seismological challenges in earthquake hazard reductions:reflections on the 2008 Wenchuan earthquake

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Science Bulletin 2018年第17期63卷 1159-1166页

作者： Yong Chen Jiupeng Hu fei peng School of Earth Sciences and Engineering Nanjing University Institute of Geophysics China Earthquake Administration Seismic Observation and Geophysical Imaging Laboratory Institute of Earthquake Forecasting China Earthquake Administration

The Wenchuan earthquake is a natural disaster. Its occurrence and aftermath have demonstrated the critical roles of seismology and earthquake engineering in reducing seismic hazards and damages. However,their existing limitations should also be underscored. This article summarized and reviewed the current scientific understanding of earthquake ruptures, and new insights gained since the Wenchuan event. This study focused on the related challenges to seismology and earthquake engineering as follows:(1) The under-estimation of earthquake risks before occurrences.(2) The current limited data regarding large earthquakes in continental thrust fault systems.(3) The causal relationship between the Wenchuan earthquake and the reservoir impoundment in its vicinity.(4) The identification of low-velocity zone in the crust and its seismogenical role.(5) The casualties and economic losses from a cascade of diverse natural hazards triggered by the ruptures, and the excellent earthquake resistance associated with tunnels in mountainous terrain.

关键词： Wenchuan earthquake Hazard reduction Low-velocity zone Secondary hazard

Experimental study on the interfacial delamination in a thermal barrier coating system at elevated temperatures

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第10期11卷 794-803页

作者： peng-fei ZHAO Fu-lin SHANG Department of Engineering Mechanics School of Aerospace Xi 'an Jiaotong University Xi 'an 710049 China

The failure mode and adhesion of thermal barrier coating (TBC) 8YSZ (ZrO2+8% (w/w) Y2O3) deposited on NiCoCrAlTaY bond coat by atmospheric plasma spraying were investigated. A grooved modified three-point bending specimen that can generate a single interface crack to facilitate the control of crack growth was adopted for testing, which was conducted at the ambient temperature of 100 °C. The morphology and composition of fractured surfaces were examined by means of a scanning electron microscopy (SEM) and an energy disperse spectroscopy (EDS). Images and spectrum show that cracks are initiated and propagated exclusively within YSZ layer adjacent to top/bond coat interface. The load-displacement curves obtained exhibit similar shapes that indicate two distinct stages in crack initiation and stable crack growth. Finite element analyses were performed to extract the adhesion strength of the TBCs. The delamination toughness of the plasma-sprayed 8YSZ coatings at 100 °C, in terms of critical strain energy release rate Gc, can be reliably obtained from an analytical solution.

关键词： Thermal barrier coating (TBC) Three-point bending test Finite element analysis Delamination toughness

Mapping global forest biomass and its changes over the first decade of the 21st century

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Science China Earth Sciences 2019年第3期62卷 585-594页

作者： Anping CHEN Shushi peng Songlin fei Department of Forestry and Natural Resources Purdue University The Woods Hole Research Center Laboratoire des Sciences du Climat et de l'Environnement(LSCE) CEA-CNRS-UVSQ

Forests played an important role in carbon sequestration during the past two decades. Using a model tree ensemble method(MTE) to regress the seven reflectance bands of EOS-Terra-MODIS satellite data against country level forest biomass carbon density(BCD) of 2001–2005 provided by United Nations' s Forest Resource Assessment(FRA), we developed a global map of forest BCD at 1 km×1 km resolution for both 2001–2005 and 2006–2010. For 2006–2010, the total global forest biomass carbon stock is estimated as 279.6±7.1 Pg C, and the tropical forest biomass carbon stock is estimated as 174.4±5.4 Pg C. During the first decade of the 21 st century, we estimated an increase of global forest biomass of 0.28±0.75 Pg C yr^(-1). Tropical forest biomass carbon stock slightly decreased(-0.31±0.60 Pg C yr^(-1)); by contrast, temperate and boreal forest biomass increased(0.58±0.28 Pg C yr^(-1)) during the same period. Our estimation of the global forest biomass carbon stock and its changes is subject to uncertainties due to lack of extensive ground measurements in the tropics, spatial heterogeneity in large countries, and different definitions of forest. The continuously monitoring of forest biomass carbon stock with MODIS satellite data will provide useful information for detecting forest changes.

关键词： Forest biomass Carbon stock Model tree ensemble(MTE) MODIS Remote sensing

The three-dimension model for the rock-breaking mechanism of disc cutter andanalysis of rock-breaking forces

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Acta Mechanica Sinica 2012年第3期28卷 675-682页

作者： Zhao-Huang Zhang fei sun School of Energy Power and Mechanical EngineeringNorth China Electric Power University102206 BeijingChina School of Foreign Languages North China Electric Power University102206 BeijingChina

To study the rock deformation with three- dimensional model under rolling forces of disc cutter, by car- rying out the circular-grooving test with disc cutter rolling around on the rock, the rock mechanical behavior under rolling disc cutter is studied, the mechanical model of disc cutter rolling around the groove is established, and the the- ory of single-point and double-angle variables is proposed. Based on this theory, the physics equations and geometric equations of rock mechanical behavior under disc cutters of tunnel boring machine （TBM） are studied, and then the bal- ance equations of interactive forces between disc cutter and rock are established. Accordingly, formulas about normal force, rolling force and side force of a disc cutter are de- rived, and their validity is studied by tests. Therefore, a new method and theory is proposed to study rock- breaking mech- anism of disc cutters.

关键词： Full face rock tunnel boring machine (TBM) Disc cutte Three-dimension model

Ultrathin self-assembly MXene/Co-based bimetallic oxide heterostructures as superior and modulated microwave absorber

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Journal of Materials Science & Technology 2023年第3期134卷 132-141页

作者： Hui-Ya Wang Xiao-Bo sun Yue Xin Shu-Hao Yang peng-fei Hu Guang-Sheng Wang School of Chemistry Beihang UniversityBeijing 102206China Research Institute of Aero-Engine Beihang UniversityBeijing 102206China

Lightweight and high-efficiency absorbing materials equipped with tunable electromagnetic properties are the foremost important factors for driving applications of 5 G smart era and military ***-ulated by the remarkable merits of heterogeneous interface engineering,a series of unique flower-like Co-based multiphases nanostructures were successfully synthesized through identical hydrothermal method,and subsequently anchored on the Ti_(3)C_(2)T_(x)*** suitable metal ion modulation is feasible to regulate the components,heterogeneous interfaces and defects for tailoring the electromag-netic parameters and microwave absorption(MA)***,the permittivity decreases of CMOT(CoO/MCo_(2)O_(4)/Ti_(3)C_(2)T_(x),M=Fe,Cu,Zn)composites proceed gradually in the order of Fe^(2+),Cu^(2+),Zn^(2+),while the MA performance with tunable absorption peak could be modulated *** asobtained CFOT-12(10 wt%),CCOT-15(10 wt%)and CZOT-15(15 wt%)exhibit excellent MA capacity with a minimum reflection loss(RL_(min))of-41.06,-52.67,-52.52 dB and corresponding effective absorption bandwidth(EAB)of 3.68,4.48,3.92 GHz at 2.10,1.90,1.80 mm,*** work expands a novel approach to construct multicomponent heterostructure for tuning the EM parameters and absorbing property,as well as realize the high efficient and light weight.

关键词： Heterogeneous interface Modulation MXene High-efficiency absorbing materials Lightweight