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24篇 您的检索式:作者名="CHENG XingHong"
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1An emission source inversion model based on satellite data and its application in air quality forecasts显示文摘This paper aims at constructing an emission source inversion model using a variational processing method and adaptive nudging scheme for the Community Multiscale Air Quality Model (CMAQ) based on satellite data to investigate the applicability of high resolution OMI (Ozone Monitoring Instrument) column concentration data for air quality forecasts over the North China. The results show a reasonable consistency and good correlation between the spatial distributions of NO2 from surface and OMI satellite measurements in both winter and summer. Such OMI products may be used to implement integrated variational analysis based on observation data on the ground. With linear and variational corrections made, the spatial distribution of OMI NO2 clearly revealed more localized distributing characteristics of NO2 concentration. With such information, emission sources in the southwest and southeast of North China are found to have greater impacts on air quality in Beijing. When the retrieved emission source inventory based on high-resolution OMI NO2 data was used, the coupled Weather Research Forecasting CMAQ model (WRF-CMAQ) performed significantly better in forecasting NO2 concentration level and its tendency as reflected by the more consistencies between the NO2 concentrations from surface observation and model result. In conclusion, satellite data are particularly important for simulating NO2 concentrations on urban and street-block scale. High-resolution OMI NO2 data are applicable for inversing NOx emission source inventory, assessing the regional pollution status and pollution control strategy, and improving the model forecasting results on urban scale.CHENG XingHong XU XiangDe DING GuoAn 2010Science China Earth Sciences2010,53,5:17
2Advances in ultra-high temperature ceramics,composites,and coatings显示文摘Ultra-high temperature ceramics(UHTCs)are generally referred to the carbides,nitrides,and borides of the transition metals,with the Group IVB compounds(Zr&Hf)and TaC as the main focus.The UHTCs are endowed with ultra-high melting points,excellent mechanical properties,and ablation resistance at elevated temperatures.These unique combinations of properties make them promising materials for extremely environmental structural applications in rocket and hypersonic vehicles,particularly nozzles,leading edges,and engine components,etc.In addition to bulk UHTCs,UHTC coatings and fiber reinforced UHTC composites are extensively developed and applied to avoid the intrinsic brittleness and poor thermal shock resistance of bulk ceramics.Recently,high-entropy UHTCs are developed rapidly and attract a lot of attention as an emerging direction for ultra-high temperature materials.This review presents the state of the art of processing approaches,microstructure design and properties of UHTCs from bulk materials to composites and coatings,as well as the future directions.Dewei NI Yuan CHENG Jiaping ZHANG Ji-Xuan LIU Ji ZOU Bowen CHEN Haoyang WU Hejun LI Shaoming DONG Jiecai HAN Xinghong ZHANG Qiangang FU Guo-Jun ZHANG 2022Journal of Advanced Ceramics2022,11,1:9
3The Electric Field Detector (EFD) onboard the ZH-1 satellite and firstobservational results显示文摘Previous studies have reported that, before or after occurrences of strong earthquakes, some low earth orbit satellites recorded ionospheric disturbances, including electromagnetic emissions and plasma fluctuations over the epicenter region or its conjugate point.Theoretically speaking, due to some electromagnetic coupling effect, electromagnetic emissions from the earthquake preparation zone could propagate from the lithosphere to the atmosphere, and could reach the ionosphere, even up to the inner magnetosphere. This paper introduces the electric field detector(EFD) onboard the ZhangHeng-1 satellite(ZH-1). The EFD is designed to measure electric field fluctuations within the broad frequency range of DC to 3.5 MHz, divided into 4 channels: ULF(DC–16 Hz), ELF(6 Hz–2.2 kHz), VLF(1.8 kHz–20 kHz) and HF(18 kHz–3.5 MHz). The sampling rates of the channels are 125 Hz, 5 kHz, 50 kHz and 10 MHz, respectively. The EFD includes4 spherical probes mounted on a over 4.5 m boom and an electronic box inside the satellite module. The resolution of the EFD is 1μV·m-1·Hz-1/2 at frequencies from DC to 16 Hz, and the sensitivity is 0.1 μV·m-1·Hz-1/2 at frequencies from 6 Hz to 2.2 kHz, 0.05 μV·m-1·Hz-1/2 in the band 1.8 kHz to 20 kHz, and 0.1μV·m-1·Hz-1/2 from 20 kHz to 3.5 MHz. The dynamic range from DC to 20 kHz is over 120 dB, and over96 dB from 20 kHz to 3.5 MHz. The EFD has two observation modes: survey mode and burst mode. The survey mode concentrates primarily on electric field power density values; the burst mode provides high sampling rate waveform data. The detailed configuration of the EFD onboard the ZH-1 is also introduced in this paper. During the six months' orbit test phase, the EFD recorded a number of natural electromagnetic emissions. Preliminary analysis of these data suggests that the EFD performs well onboard the ZH-1 and is meeting the requirements of the scientific objectives of ZH-1.JianPing Huang JunGang Lei ShiXun Li ZhiMa Zeren Cheng Li XingHong Zhu WeiHao Yu 2018Earth and Planetary Physics2018,2,6:8
4Complex sources of air-soil-water pollution processes in the Miyun reservoir region显示文摘The comprehensive impact of atmospheric dry deposition and wet deposition and the pollution sources of farmlands, mining areas, and towns along the Baihe River on the water quality of Miyun reservoir is investigated from the angle of the complex sources of air-soil-water pollution processes, in the context of the 1990-2001 precipitation chemical data at Shangdianzi station--a WMO regional background air pollution monitoring station 15 km far from the Miyun reservoir, in conjunction with the atmospheric dry deposition and wet deposition data of the 2002-2003 Beijing City Air Pollution Observation Field Experiment (BECAPEX). Analysis results suggest that the major ions in precipitation in the Miyun reservoir region in this period were SO, NO, NH and Ca2+; wet acid deposition quantity of Miyun reservoir in the summer half year (April to September) was greater than the quantity in the winter half year (October to March), and the annual wet acid deposition in the reservoir exhibited a rising trend with the mean 1038.45 t, the maximum 1766.31 t occurred in 1996, and the minimum 604.02 t in 1994; the long-term averaged pH of atmospheric precipitation in the Miyun reservoir region was 5.20, i.e. weakly acidic, and the interannual variation of pH values displayed a falling trend. pH values of water body at various depths in the Miyun reservoir were all greater than 7.0, but they exhibited vertical and horizontal nonhomogeneity, and at the same region pH decreased vertically with depth; the 2002 and 2003 annual dustfalls in the Miyun reservoir were 13513.08 t and 3577.64 t, respectively, and the spring dustfall was the number one in a year, accounting for the 61.91% and 44.56% of the annual totals of 2002 and 2003, respectively. Because the atmospheric dry deposition and wet depositions contain multiple types heavy metal elements and harmful elements, they to some extent exacerbated the eutrophication, acidification and potential heavy metal pollution of the reservoir water. The above comprehensive analysis results reveal the complex source characters of the air-soil-water pollution process and the multi-sphere interaction effect. Besides, summer (rainy season) is a season when local soil pollutants enter the water system of reservoir after being washed out by torrential rain or heavy precipitation, which starts the air-soil- water chaining pollution processes, and results in the water pollution of rivers and reservoirs. It is found from the statistical analysis in this paper that the water pollution of Miyun reservoir was correlated with the rain wash-out and confluent flow in the peripheral and upstream local region of the reservoir, and the pollutant concentration of the reservoir water was significantly correlated with the upstream local region precipitation. Those correlation characters reveal the effect of the air-soil-water multi-spheric interaction of reservoir water pollution process. This paper presents the point of view of the complex source analysis of reservoir water pollution and a technical approach for tracing the spatial distribution of the upstream pollution source of the water systems of reservoir.YANG Dongzhen, XU Xiangde, LIU Xiaoduan, XU Qing, DING Guoan, CHENG Xinghong, CHEN Huailiang, ZHOU Huaigang, WANG Zhenfa, WANG Wenyan Key Laboratory of Atmospheric Chemistry, Center for Atmosphere Watch and Services, Chinese Academy of Meteorological Sciences, CMA, Beijing 100081, China Key Laboratory of Meteorological Disasters, CAMS, Beijing 100081, China National Center for Geological Testing, Beijing 100037, China Meteorological Bureau of Henan Province, Zhenzhou 450000, China Shangdianzi Background Atmospheric Pollution Observation Station, Miyun County, Beijing 101507, China 2005Science China Earth Sciences2005,48,z2:4
5Cross-calibration on the electromagnetic field detection payloads of the China Seismo-Electromagnetic Satellite显示文摘The China Seismo-Electromagnetic Satellite(CSES)deploys three payloads to detect the electromagnetic environment in the ionosphere.The tri-axial fluxgate magnetometers(FGM),as part of the high precision magnetometer(HPM),measures the Earth magnetic vector field in a frequency range from direct current(DC)to 15 Hz.The tri-axial search coil magnetometer(SCM)detects the alternating current(AC)related magnetic field in a frequency range from several Hz to 20 k Hz,and the electric field detector(EFD)measures the spatial electric field in a broad frequency band from DC to 3.5 MHz.This work mainly crosscalibrates the consistency of these three payloads in their overlapped detection frequency range and firstly evaluates CSES’s timing system and the sampling time differences between EFD and SCM.A sampling time synchronization method for EFD and SCM waveform data is put forward.The consistency between FGM and SCM in the ultra-low-frequency(ULF)range is validated by using the magnetic torque(MT)signal as a reference.A natural quasiperiodic electromagnetic wave event verifies SCM and EFD’s consistency in extremely low-frequency and very low-frequency(ELF/VLF)bands.This cross-calibration work is helpful to upgrade the data quality of CSES and brings valuable insights to similar electromagnetic detection solutions by low earth orbit satellites.ZHIMA Zeren ZHOU Bin ZHAO ShuFan WANG Qiao HUANG JianPing ZENG Li LEI JunGang CHEN Yu LI Cheng YANG DeHe SUN XiaoYing MIAO YuanQing ZHU XingHong SHEN XuHui 2022Science China(Technological Sciences)2022,65,6:3
6Using PyC modified 3D carbon fiber to reinforce UHTC under low temperature sintering without pressure显示文摘Finding the optimum balance between strength and toughness,as well as acquiring reliable thermal shock resistance and oxidation resistance,has always been the most concerned topic in the discussion of ultra-high temperature ceramic composites.Herein,PyC modified 3D carbon fiber is used to reinforce ultra-high temperature ceramic(UHTC).The macroscopic block composite with large size is successfully fabricated through low temperature sintering at 1300℃without pressure.The prepared PyC modified 3D C_(f)/ZrC-SiC composites simultaneously possess excellent physical and chemical stability under the synergistic effect of PyC interface layer and low temperature 1/2 sintering without pressure.The fracture toughness is increased in magnitude to 13.05±1.72 MPa·m^(1/2)accompanied by reliable flexural strength of 251±27 MPa.After rapid thermal shock spanning from room temperature(RT)to 1200℃,there are no visible surface penetrating cracks,spalling,or structural fragmentation.The maximum critical temperature difference reaches 875℃,which is nearly three times higher than that of traditional monolithic ceramics.The haunting puzzle of intrinsic brittleness and low damage tolerance are resolved fundamentally.Under the protection of PyC interface layer,the carbon fibers around oxide layer and matrix remain structure intact after static oxidation at 1500℃for 30 min.The oxide layer has reliable physical and chemical stability and resists the erosion from fierce oxidizing atmosphere,ensuring the excellent oxidation resistance of the composites.In a sense,the present work provides promising universality in designability and achievement of 3D carbon fiber reinforced ceramic composites.Baihe DU Yuan CHENG Liancai XUN Shuchang ZHANG Jing TONG Qingrong LV Shanbao ZHOU Ping HU Xinghong ZHANG 2021Journal of Advanced Ceramics2021,10,4:3
7Fungal diversity notes 111-252-taxonomic and phylogenetic contributions to fungal taxa显示文摘This paper is a compilation of notes on 142 fungal taxa,including five new families,20 new genera,and 100 new species,representing a wide taxonomic and geographic range.The new families,Ascocylindricaceae,Caryosporaceae and Wicklowiaceae(Ascomycota)are introduced based on their distinct lineages and unique morphology.The new Dothideomycete genera Pseudomassariosphaeria(Amniculicolaceae),Heracleicola,Neodidymella and Pseudomicrosphaeriopsis(Didymellaceae),Pseudopithomyces(Didymosphaeriaceae),Brunneoclavispora,Neolophiostoma and Sulcosporium(Halotthiaceae),Lophiohelichrysum(Lophiostomataceae),Galliicola,Populocrescentia and Vagicola(Phaeosphaeriaceae),Ascocylindrica(Ascocylindricaceae),Elongatopedicellata(Roussoellaceae),Pseudoasteromassaria(Latoruaceae)and Pseudomonodictys(Macrodiplodiopsidaceae)are introduced.The newly described species of Dothideomycetes(Ascomycota)are Pseudomassariosphaeria bromicola(Amniculicolaceae),Flammeascoma lignicola(Anteagloniaceae),Ascocylindrica marina(Ascocylindricaceae),Lembosia xyliae(Asterinaceae),Diplodia crataegicola and Diplodia galiicola(Botryosphaeriaceae),Caryospora aquatica(Caryosporaceae),Heracleicola premilcurensis and Neodidymella thailandicum(Didymellaceae),Pseudopithomyces palmicola(Didymosphaeriaceae),Floricola viticola(Floricolaceae),Brunneoclavispora bambusae,Neolophiostoma pigmentatum and Sulcosporium thailandica(Halotthiaceae),Pseudoasteromassaria fagi(Latoruaceae),Keissleriella dactylidicola(Lentitheciaceae),Lophiohelichrysum helichrysi(Lophiostomataceae),Aquasubmersa japonica(Lophiotremataceae),Pseudomonodictys tectonae(Macrodiplodiopsidaceae),Microthyrium buxicola and Tumidispora shoreae(Microthyriaceae),Alloleptosphaeria clematidis,Allophaeosphaeria cytisi,Allophaeosphaeria subcylindrospora,Dematiopleospora luzulae,Entodesmium artemisiae,Galiicola pseudophaeosphaeria,Loratospora luzulae,Nodulosphaeria senecionis,Ophiosphaerella aquaticus,Populocrescentia forlicesenensis and Vagicola vagans(Phaeosphaeriaceae),Elongatopedicellata lignicola,Roussoella magnatum and Roussoella angustior(Roussoellaceae)and Shrungabeeja longiappendiculata(Tetraploasphaeriaceae).The new combinations Pseudomassariosphaeria grandispora,Austropleospora archidendri,Pseudopithomyces chartarum,Pseudopithomyces maydicus,Pseudopithomyces sacchari,Vagicola vagans,Punctulariopsis cremeoalbida and Punctulariopsis efibulata Dothideomycetes.The new genera Dictyosporella(Annulatascaceae),and Tinhaudeus(Halosphaeriaceae)are introduced in Sordariomycetes(Ascomycota)while Dictyosporella aquatica(Annulatascaceae),Chaetosphaeria rivularia(Chaetosphaeriaceae),Beauveria gryllotalpidicola and Beauveria loeiensis(Cordycipitaceae),Seimatosporium sorbi and Seimatosporium pseudorosarum(Discosiaceae),Colletotrichum aciculare,Colletotrichum fusiforme and Colletotrichum hymenocallidicola(Glomerellaceae),Tinhaudeus formosanus(Halosphaeriaceae),Pestalotiopsis subshorea and Pestalotiopsis dracaenea(Pestalotiopsiceae),Phaeoacremonium tectonae(Togniniaceae),Cytospora parasitica and Cytospora tanaitica(Valsaceae),Annulohypoxylon palmicola,Biscogniauxia effusae and Nemania fusoideis(Xylariaceae)are introduced as novel species to order Sordariomycetes.The newly described species of Eurotiomycetes are Mycocalicium hyaloparvicellulum(Mycocaliciaceae).Acarospora septentrionalis and Acarospora castaneocarpa(Acarosporaceae),Chapsa multicarpa and Fissurina carassensis(Graphidaceae),Sticta fuscotomentosa and Sticta subfilicinella(Lobariaceae)are newly introduced in class Lecanoromycetes.In class Pezizomycetes,Helvella pseudolacunosa and Helvella rugosa(Helvellaceae)are introduced as new species.The new families,Dendrominiaceae and Neoantrodiellaceae(Basidiomycota)are introduced together with a new genus Neoantrodiella(Neoantrodiellaceae),here based on both morphology coupled with molecular data.In the class Agaricomycetes,Agaricus pseudolangei,Agaricus haematinus,Agaricus atrodiscus and Agaricus exilissimus(Agaricaceae),Amanita melleialba,Amanita pseudosychnopyramis and Amanita subparvipantherina(Amanitaceae),Entoloma calabrum,Cora barbulata,Dictyonema gomezianum and Inocybe granulosa(Inocybaceae),Xerocomellus sarnarii(Boletaceae),Cantharellus eucalyptorum,Cantharellus nigrescens,Cantharellus tricolor and Cantharellus variabilicolor(Cantharellaceae),Cortinarius alboamarescens,Cortinarius brunneoalbus,Cortinarius ochroamarus,Cortinarius putorius and Cortinarius seidlii(Cortinariaceae),Hymenochaete micropora and Hymenochaete subporioides(Hymenochaetaceae),Xylodon ramicida(Schizoporaceae),Colospora andalasii(Polyporaceae),Russula guangxiensis and Russula hakkae(Russulaceae),Tremella dirinariae,Tremella graphidis and Tremella pyrenulae(Tremellaceae)are introduced.Four new combinations Neoantrodiella gypsea,Neoantrodiella thujae(Neoantrodiellaceae),Punctulariopsis cremeoalbida,Punctulariopsis efibulata(Punctulariaceae)are also introduced here for the division Basidiomycota.Furthermore Absidia caatinguensis,Absidia koreana and Gongronella koreana(Cunninghamellaceae),Mortierella pisiformis and Mortierella formosana(Mortierellaceae)are newly introduced in the Zygomycota,while Neocallimastix cameroonii and Piromyces irregularis(Neocallimastigaceae)are introduced in the Neocallimastigomycota.Reference specimens or changes in classification and notes are provided for Alternaria ethzedia,Cucurbitaria ephedricola,Austropleospora,Austropleospora archidendri,Byssosphaeria rhodomphala,Lophiostoma caulium,Pseudopithomyces maydicus,Massariosphaeria,Neomassariosphaeria and Pestalotiopsis montellica.Hiran A.Ariyawansa Kevin D.Hyde Subashini C.Jayasiri Bart Buyck K.W.Thilini Chethana Dong Qin Dai Yu Cheng Dai Dinushani A.Daranagama Ruvishika S.Jayawardena Robert Lücking Masoomeh Ghobad-Nejhad Tuula Niskanen Kasun M.Thambugala Kerstin Voigt Rui Lin Zhao Guo-Jie Li Mingkwan Doilom Saranyaphat Boonmee Zhu L.Yang Qing Cai Yang-Yang Cui Ali H.Bahkali Jie Chen Bao Kai Cui Jia Jia Chen Monika C.Dayarathne Asha J.Dissanayake Anusha H.Ekanayaka Akira Hashimoto Sinang Hongsanan E.B.Gareth Jones Ellen Larsson Wen Jing Li Qi-Rui Li Jian Kui Liu Zong Long Luo Sajeewa S.N.Maharachchikumbura Ausana Mapook Eric H.C.McKenzie Chada Norphanphoun Sirinapa Konta Ka Lai Pang Rekhani H.Perera Rungtiwa Phookamsak Chayanard Phukhamsakda Umpava Pinruan Emile Randrianjohany Chonticha Singtripop Kazuaki Tanaka Cheng Ming Tian Saowaluck Tibpromma Mohamed A.Abdel-Wahab Dhanushka N.Wanasinghe Nalin N.Wijayawardene Jin-Feng Zhang Huang Zhang Faten A.Abdel-Aziz Mats Wedin Martin Westberg Joseph F.Ammirati Timur S.Bulgakov Diogo X.Lima Tony M.Callaghan Philipp Callac Cheng-Hao Chang Luis F.Coca Manuela Dal-Forno Veronika Dollhofer Kateřina Fliegerová Katrin Greiner Gareth W.Griffith Hsiao-Man Ho Valerie Hofstetter Rajesh Jeewon Ji Chuan Kang Ting-Chi Wen Paul M.Kirk Ilkka Kytövuori James D.Lawrey Jia Xing Hong Li Zou Yi Liu Xing Zhong Liu Kare Liimatainen H.Thorsten Lumbsch Misato Matsumura Bibiana Moncada Salilaporn Nuankaew Sittiporn Parnmen AndréL.C.M.de Azevedo Santiago Sujinda Sommai Yu Song Carlos A.F.de Souza Cristina M.de Souza-Motta Hong Yan Su Satinee Suetrong Yong Wang Syuan-Fong Wei Ting Chi Wen Hai Sheng Yuan Li Wei Zhou Martina Réblová Jacques Fournier Erio Camporesi J.Jennifer Luangsa-ard Kanoksri Tasanathai Artit Khonsanit Donnaya Thanakitpipattana Sayanh Somrithipol Paul Diederich Ana M.Millanes Ralph S.Common Marc Stadler Ji Ye Yan XingHong Li Hye Won Lee Thi T.T.Nguyen Hyang Burm Lee Eliseo Battistin Orlando Marsico Alfredo Vizzini Jordi Vila Enrico Ercole Ursula Eberhardt Giampaolo Simonini Hua-An Wen Xin-Hua Chen Otto Miettinen Viacheslav Spirin Hernawati 2015Fungal Diversity2015,,6:2
8Thermal response, oxidation and ablation of ultra–high temperature ceramics, C/SiC, C/C, graphite and graphite–ceramics显示文摘Various thermal protection materials exhibit obviously different and complicated thermal response,oxidation and ablation behavior,which are very important for the appropriate design and selection.However,the relative researches are very few currently.In this work,the thermal response,oxidation and ablation behavior of representative thermal protection materials including ultra-high temperature ceramics,C/SiC,C/C, graphite and graphite-ceramic were investigated systematically in strong heat flux,high enthalpy and low-pressure environments.Thermal response of these materials was analyzed based on experimental results and thermal energy balance that accounts for all of the heat transfer processes transporting energy into and out of the surface.Many factors were playing important roles in the thermal response including thermal conductivity,volumetric heat capacity,catalytic efficiency,emissivity and oxidation characteristics of the materials.The importance of each factor not only depends on the material characteristics such as material composition and phase content but also environment parameters including heat flux,enthalpy,pressure and testing time.The comparisons and relationships of oxidation and ablation behaviors for these materials under extreme environments were also illustrated in detail.Furthermore,thermal response and ablation behaviors of pre-oxidized material or repeated tests were also performed to evaluate the effect of pre-treatment on the performance and reusability of thermal protection materials.This work offers guiding significance for the appropriate design and selection of thermal protection materials.Xinghong Zhang Baihe Du Ping Hu Yuan Cheng Jiecai Han 2022Journal of Materials Science & Technology2022,,7:2
9Application of an Adaptive Nudging Scheme in Air Quality Forecasting in China显示文摘Xiangde Xu Lian Xie Xinghong Cheng 2008J Appl Meteor Climatol2008,47,8:1
10Organochlorine pesticides in particulate matter of Beijing, China显示文摘Wang Xiaofei Li Xinghong Cheng Hangxin 2008Journal of Hazardous Materials2008,155,12:1
11GCMC simulation of hydrogen physisorption on carbon nanotubes and nanotube arrays 显示文摘Jinrong Cheng Xinghong Yuan Li Zhao 2004Carbon2004,42,:1
12Distribution of HCHs and DDTs in Soils from Beijing City, China显示文摘Xinghong Li Youfeng Zhu Xiufen Liu Shan Fu Xiaobai Xu Hangxin Cheng 2006Archives of Environmental Contamination and Toxicology2006,,3:1
13Analysis and elimination of tri-band beacon interference with the fluxgate sensors onboard CSES显示文摘High precision magnetometer(HPM)is a magnetic field detection payload onboard China Seismo-Electromagnetic Satellite(CSES),including two fluxgate magnetometers(FGM)and a coupled dark state magnetometer(CDSM).Observations show that FGM appears to be influenced when tri-band beacon(TBB)is powered on and emits electromagnetic waves.The interference phenomenon is further validated based on both in-orbit observation analysis and electromagnetic compatibility(EMC)tests on the ground.A joint correction algorithm based on the least square fitting and first-order difference method according to scalar magnetometer data is proposed to eliminate the interference.The algorithm significantly improves the consistency of HPM data.After correction,the average scalar deviation error could be reduced from 9.0 nT to around 0.7 nT.TONG YuQi CHENG BingJun MIAO YuanQing ZHOU Bin ZHU XingHong YANG YanYan LIU Ji GOU XiaoChen ZHANG YiTeng WANG JinDong LI Lei MAGNES Werner LAMMEGGER Roland POLLINGER Andreas ZEREN Zhima SHEN XuHui 2021Science China(Technological Sciences)2021,64,10:1
14Microstructure and mechanical properties of laminated ZrB2-SiCceramics with ZrO2 interface layers显示文摘Wei Chun Cheng Zhang Xinghong Hu Ping 0,,:1
15Distribution of HCHs and DDTs in Soils from Beijing City, China显示文摘Xinghong Li Youfeng Zhu Xiufen Liu Shan Fu Xiaobai Xu Hangxin Cheng 2006Archives of Environmental Contamination and Toxicology2006,,3:1
16Microstructural regulation,oxidation resistance,and mechanical properties of C_(f)/SiC/SiHfBOC composites prepared by chemical vapor infiltration with precursor infiltration pyrolysis显示文摘To further improve the oxidation resistance of polymer derived ceramic(PDC)composites in harsh environments,Cf/SiC/SiHfBOC composites were prepared by chemical vapor infiltration(CVI)and precursor impregnation pyrolysis(PIP)methods.The weight retention change,mechanical properties,and microstructure of C/SiC/SiHfBOC before and after oxidation in air were studied in details.Microscopic analyses showed that only the interface between the ceramics and fibers was oxidized to some extent,and hafnium had been enriched on the composite surface after oxidizing at different temperature.The main oxidation products of Cf/SiC/SiHfBOC composites were Hf0_(2)and HfSi04 after oxidation at 1500℃for 60 min.Moreover,the weight retention ratio and compressive strength of the Cf/SiC/SiHfBOC composites are 83.97%and 23.88±3.11 MPa,respectively.It indicates that the Cf/SiC/SiHfBOC composites should be promising to be used for a short time in the oxidation environment at 1500℃.Yang LYU Baihe DU Guiqing CHEN Guangdong ZHAO Yuan CHENG Shanbao ZHOU Qingrong LV Xinghong ZHANG Wenbo HAN 2022Journal of Advanced Ceramics2022,11,1:1
17Organochlorine pesticides in particulate matter of Bei- jing, China显示文摘Wang Xiaofei Li Xinghong Cheng Hangxin 2008J Hazard Mater2008,155,12:1
18Organochlorine pesticides in particulate matter of bei- jing, China显示文摘Wang Xiaofei Li Xinghong Cheng Hangxin 2008J Hazard Mater2008,155,12:1
19Synthesis and formation mechanism of HfB_(2) ultrafine powders with low oxygen via flocculating settling assisted process and carbo/borothermal reduction显示文摘In this study,ultrafine HfB_(2) powders with low oxygen were synthesized by a flocculating settling process which yielded ceramic precursors and subsequent carbo/borothermal reduction of the precursors.The liquid phase precursor method can achieve uniform mixing of components at the molecular level through multiple complexation reactions,and then realize the carbo/borothermal reduction reaction at a lower temperature to obtain ultrapure HfB2 powders.The as-resulted quasi-spherical HfB2 powders under the optimum conditions(atomic molar ratio M:B:C=1:2.8:10)calcined at 1500°C for 1 h have an average particle size of 205 nm and an oxygen content of 0.097 wt.%.Detailed analysis of the phase evolution of precursors shows that the formation of HfB2 particles is a mass diffusion mode from the external to internal HfO_(2)cores.We reveal that below 1300°C,HfC is not an intermediate product of HfB2 powder during the transition of precursors.Instead,HfC was formed as a by-product at high temperatures in the carbo/borothermal reduction process.The proposed formation mechanism of HfB_(2) is completely different from the traditional two-step transformation method.After the sintering of the ultrafine powders,the HfB_(2) ceramics show a relative density of 96.1%and superior mechanical properties compared to other works.Furthermore,by simply replacing the initial metal source,chlorinated group IV and V transitional metals(Ti,Zr,Ta,Nb)can also convert into high-purity and ultrafine diborides.This work shows that flocculating settling assisted carbo/borothermal reduction has potential in lot size production of various high-purity and ultrafine boride powders.Zhen Wang Yuan Cheng Kewei Li Tianxu Wang Mengen Hu Chunxue Zheng Xinyang Li Zhulin Huang Xiaoye Hu Yue Li Xinghong Zhang 2023Journal of Materials Science & Technology2023,,33:0
20Medium and high-entropy transition mental disilicides with improved infrared emissivity for thermal protection applications显示文摘Transition metal disilicides are widely used as heating elements and infrared emission coatings.However,the limited intrinsic infrared emissivity and high thermal conductivity are the main limitations to their applications as infrared emission coatings in the thermal protection system.To cope with these prob-lems,four medium and high-entropy transition metal disilicides,i.e.,(V_(0.25)Ta_(0.25)Mo_(0.25)W_(0.25))Si_(2)(ME-1),(Nb_(0.25)Ta_(0.25)Mo_(0.25)W_(0.25))Si_(2)(ME-2),(V_(0.2)Nb_(0.2)Ta_(0.2)Mo_(0.2)W_(0.2))Si_(2)(HE-1),and(Cr_(0.2)Nb_(0.2)Ta_(0.2)Mo_(0.2)W_(0.2))Si_(2)(HE-2),were designed and synthesized by spark plasma sintering method using transition metal binary disilicides as precursors.The introduction of multi-elements into transition metal disilicides not only im-proved the infrared emissivity but also reduced the electrical and thermal conductivity.Among them,(Cr_(0.2)Nb_(0.2)Ta_(0.2)Mo_(0.2)W_(0.2))Si_(2)(HE-2)had the lowest electrical conductivity of 3789 S cm-1,which is over one order of magnitude lower than that of MoSi_(2)(50000 S cm^(-1)),and total infrared emissivity of 0.42 at room temperature,which is nearly double of that of TaSi_(2).Benefiting from low electrical conductivity and phonon scattering due to lattice distortion,the medium and high-entropy transition metal disilicides also demonstrated a significant decline in thermal conductivity compared to their binary counterparts.Of all samples,HE-2 exhibited the lowest thermal conductivity of 6.4 W m^(−1)K^(−1).The high-entropy tran-sition metal disilicides also present excellent oxidation resistance at high temperatures.The improved infrared emissivity,reduced thermal conductivity,excellent oxidation resistance,and lower densities of these medium and high-entropy transition metal disilicides portend that they are promising as infrared emission coating materials for applications in thermal protection systems.Juntao Song Yuan Cheng Huimin Xiang Fu-Zhi Dai Shun Dong Guiqing Chen Ping Hu Xinghong Zhang Wenbo Han Yanchun Zhou 2023Journal of Materials Science & Technology2023,,5:0
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