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Ef.ect of.f.re severity on physical and biochemical soil properties in Zagros oak(Quercus brantii Lindl.)f.rests in Iran

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Journal of.f.restry Research 2017年第1期28卷 95-104页

作者： M.Heydari A.Rostamy f.Najaf. d.c.dey department of.f.rest Science Faculty of Agriculture and Natural ResourcesIlam UniversityIlamIran department of.f.rest Science Islamic Azad UniversityIlam BranchIlamIran Expert in f.rest Science Ilarn Natural Resources OfficeIlamIran Research f.rester Northern Research StationUSDA Fores tService202 Natural Resources BldgColumbiaMO 65211USA

f.re af.ects the physical and chemical properties and soil biological activity of.natural ecosystems. This study was conducted in the Miyan Tang region, Ilam Province in western Iran. The study site was 110 hectares, where we sampled soils in areas that were classif.ed by f.re severity： low （LS）, high （HS） and medium severity （MS）, and unburned （UB）, which served as the control. In each severity class, 25 transect points were randomly selected f.r measurement. Around each transect plot center, 3 soil samples were selected randomly and soils collected f.om the 0 to 20 cm depth were combined into a composite sample that was used in laboratory analysis to represent conditions at that point. Plots in the UB and LS f.re classes had similar soil conditions and had higher values of.f.ctors such as saturated moisture, organic carbon, carbon dioxide, and silt and clay content. In contrast, plots in the HS and MS f.re severity classes were clustered in the positive direction along the f.rst axis that represented gradients in soil acidity, electrical conductivity, cation exchange capacity, accessible phosphorus, accessible potassium, bulk density, and sand. Soil attributes were similar in areas of.HS and MS f.re severity classes, whereas soil conditions in the LS class and UB controls were most similar. f.re in the LS areas either did not signif.cantly alter the physicalchemical soil properties and microbial basal respiration, or soils were able to recover quickly af.er being burned.

关键词： f.re severity Oak Soil respiration Physical and chemical soil properties

Ef.EcTS Of.Pb cOMPOUNd AddITIVES ON THE PROPERTIES Of.yBa_2cu_3O_(7-δ)

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Acta Metallurgica Sinica(English Letters) 2005年第2期18卷 145-148页

作者： f.H.Li Z.G.f.n J.Wang c.S.Liu d.W.Soh y.J.cho Schoolof.aterialandMetallurgy NortheasternUniversityShenyang110004China MyongjiUniversity Yongjin449-728SouthKorea

The melting temperature and critical transition temperature Tc of.yBa2cu3O7-δ with def.rent content additives of.PbO and BaPbO3 were studied. When PbO was doped in yBa2cu3O7-δ, the melting temperature of.yBa2cu3O7-δ was reduced, however its superconductivity was weakened. f.om the XRd pattern of.the sintered mixture of.yBa2cu3O7-δ and PbO, it was known that there was a reaction between yBa2cu3O7-δ and PbO, and the product was BaPbO3. Hence dif.erent contents of.BaPbO3 (10mass%, 20mass% and 30mass%) were added in yBa2cu3O7-δ. It was proved that there were no reactions between yBa2cu3O7-δ and BaPbO3. And the superconductivity of.the mixtures was much better than that of.the samples with PbO additive.

关键词： yBa2cu3O7-δ PbO additive melting temperature superconductivity

High-perf.rmance oxygen reduction and evolution carbon catalysis： f.om mechanistic studies to device integration

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Nano Research 2017年第4期10卷 1163-1177页

作者： John W. f. To Jia Wei desmond Ng Samira Siahrostami Ai Leen Koh yangjin Lee Zhihua chen Kara d. f.ng Shucheng chen Jiajun He Won-Gyu Bae Jennif.r Wilcox Hu young Jeong Kwanpyo Kim f.lix Studt Jens K. Nфrskov thomas f. Jaramillo Zhenan Bao department of.chemical Engineering Stan ford University Stanford CA 94305 USA Institute of.chemical and Engineering Sciences Agency for Science Technology and Research Jurong Island 627833 Singapore Stanf.rd Nano Shared f.cilities Stanford University Stanford CA 94305 USA department of.Physics Ulsan National Institute of Science and Technology (UNIST) Ulsan 689-798 Republic of Korea department of.chemical and Biological Engineering Colorado School of Mines Golden CO 80401 USA UNIST central Research f.cilities (UcRf. Ulsan National Institute of Science and Technology (UNIST) Ulsan 689-798 Republic of Korea SUNcAT center f.r Interf.ce Science and catalysis SLAc National Accelerator Laboratory 2575 Sand Hill Road Menlo Park CA 94025 USA Institute of.catalysis Research and Technology Karlsruhe Institute of Technology Hermann-von-Helmholtz Platz 1 76344 Eggenstein-Leopoldshafen Germany Institute f.r chemical Technology and Polymer chemistry Karlsruhe Institute of Technology Engesserstr. 18 76131 Karlsruhe Germany

The development of.high-perf.rmance and low-cost oxygen reduction and evolution catalysts that can be easily integrated into existing devices is crucial f.r the wide deployment of.energy storage systems that utilize O2-H2O chemistries, such as regenerative f.el cells and metal-air batteries. Herein, we report an NHB-activated N-doped hierarchical carbon （NHc） catalyst synthesized via a scalable route, and demonstrate its device integration. The NHc catalyst exhibited good perf.rmance f.r both the oxygen reduction reaction （ORR） and the oxygen evolution reaction （OER）, as demonstrated by means of.electrochemical studies and evaluation when integrated into the oxygen electrode of.a regenerative f.el cell. The activities observed f.r both the ORR and the OER were comparable to those achieved by state-of.the-art Pt and Ir catalysts in alkaline environments. We have f.rther identif.ed the critical role of.carbon def.cts as active sites f.r electrochemical activity through density f.nctional theory calculations and high-resolution TEM visualization. This work highlights the potential of.NHc to replace commercial precious metals in regenerative f.el cells and possibly metal-air batteries f.r cost-ef.ective storage of.intermittent renewable energy.

关键词： electrocatalysis porous carbon density f.nctional theory

Near zero thermal perf.rmance loss of.Al-Si microcapsules with f.bers network emb e dde d Al_(2)O_(3)/AlN shell

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Journal of.Materials Science & Technology 2024年第9期176卷 48-56页

作者： J.X.Zhang M.J.Zhang H.f.Li H.Z.Gu d.chen c.H.Zhang y.f.Tian E.J.Wang Q.N.Mu The State Key Laboratory of.Ref.actories and Metallurgy(Wuhan University of.Science and Technology) Wuhan 430081China f.culty of.Materials Science and chemistry Engineering Research Center of Nano-Geomaterials of Ministry of EducationChina University of GeosciencesWuhan 430078China Henan Shenma carbon Reduction Technology co. LtdPingdingshan 467000China

Al-Si alloy,a high temperature phase change material,has great potential in thermal management due to its advantages of.high heat storage density and thermal *** of.Al-Si alloy is one of.the ef.ective techniques to solve high temperature leakage and *** this paper,commercial Al-10Si alloy micro powders were encapsulated with f.exible ceramic shells whose total thickness is below 1μm by hydrothermal treatment and heat treatment in N_(2) *** compositions and microstructures were characterized by XRd,SEM and *** shell was composed of.AlN f.bers network structure embedded withα-Al_(2)O_(3)/AlN which prevented the alloy f.om leaking and oxidizing,as well as had excellent thermal *** latent heat of.microcapsules was 351.8 J g^(-1)f.r absorption and 372.7 J g^(-1)f.r *** microcapsules showed near zero thermal perf.rmance loss with latent heat storage(LHS)/release(LHR)was 353.2/403.7 J g^(-1)af.er 3000 *** with the published Al-Si alloy microcapsules,both high heat storage density and super thermal cycle stability were achieved,showing promising development prospects in high temperature thermal management.

关键词： Al-Si alloy Microcapsules ceramic shell AlN f.ber network Thermal perf.rmance

Review of.Electrogravitics &Electrokinetics Propulsion

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International Journal of.Geosciences 2015年第4期6卷 413-428页

作者： thomas f. Valone R&d department Integrity Research Institute Beltsville MD USA

Electrogravitics and electrokinetics can be traced to T. Townsend Brown’s f.rst article “How I control Gravity” (Science and Invention, 1929) with the unexplained alignment of.the “molecular gravitors”. Brown reported that the dielectrics had high propulsive f.rce when the “dif.erently charged elements” were aligned with the voltage source. Perhaps electrogravitics was also revealed in the article “Gravity Nullif.ed: Quartz crystals charged by High f.equency currents Lose Their Weight” which appeared two years earlier in the same magazine in September of.1927. The editors had a change of.heart however, in the f.llowing issue, they rescinded the article. Much of.what we know about T. T. Brown is f.om his numerous patents and articles, reprinted inElectrogravitics Systems Volume I, by this author who was f.rtunate to correspond with him in 1981 when he was at the University of.f.orida. A sample of.his detailed correspondence is contained in the out-of.print book,?Ether-Technology:?A Rational Approach to Gravity-control?by Rho Sigma (1977) and in the recent?def.ing Gravity:?The Parallel Universe of.T. Townsend Brown,?Paul Schatzkin, (2009, Embassy Books). Also, a f.ve-minute Brown-Bahnson Lab video online shows many of.the experimental models that Brown developed toward 1960 with colleague Agnew Bahnson? (http://***/watch?v=Rp4hygod3RU).

关键词： Electrogravitics Electrokinetics Gravitor Gravity Antigravity High Voltage f.rce Production Gravitics

Impacts of.Anthropogenic f.rcings and El Nio on chinese Extreme Temperatures

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Advances in Atmospheric Sciences 2018年第8期35卷 98-106页

作者： N. f.EycHET S. SPARROW S. f. B. TETT M. J. MINETER G. c. HEGERL d. c. H. WALLOM School of.Geosciences University of Edinburgh Crew Building The King's Buildings Edinburgh EH9 3FF UK Oxf.rd e-Research centre University of Oxford Oxford OX1 2JD United Kingdom

This study investigates the potential inf.uences of.anthropogenic f.rcings and natural variability on the risk of.summer extreme temperatures over china. We use three multi-thousand-member ensemble simulations with dif.erent f.rcings （with or without anthropogenic greenhouse gases and aerosol emissions） to evaluate the human impact, and with sea surf.ce temperature patterns f.om three dif.erent years around the E1 Nino-Southern Oscillation （ENSO） 2015/16 event （years 2014, 2015 and 2016） to evaluate the impact of.natural variability. A generalized extreme value （GEV） distribution is used to f.t the ensemble results. Based on these model results, we f.nd that, during the peak of.ENSO （2015）, daytime extreme tem- peratures axe smaller over the central china region compared to a normal year （2014）. during 2016, the risk of.nighttime extreme temperatures is largely increased over the eastern coastal region. Both anomalies are of.the same magnitude as the anthropogenic inf.uence. Thus, ENSO can amplif. or counterbalance （at a regional and annual scale） anthropogenic ef.ects on extreme summer temperatures over china. changes are mainly due to changes in the GEV location parameter. Thus, anomalies are due to a shif. in the distributions and not to a change in temperature variability.

关键词： extreme temperatures ENSO anthropogenic impact climate risk

EVALUATION Of.THE TIME dEPENdENT f.ILURE ASSESSMENT cURVES f.R 10crMo910 ANd 316 SS AT 550℃

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 443-449页

作者： f.Z.Xuan S.d.Tu Z.d.Wang c.W.Ma School of.Mechanical Engineering East China University of Science and Technology Shanghai 200237ChinaSchool of Mechanical Engineering East China University of Science and Technology Shanghai 200237ChinaSchool of Mechanical Engineering East China University of Science and Technology Shanghai 200237ChinaSchool of Mechanical Engineering East China University of Science and Technology Shanghai 200237China

10crMo910 and 316 stainless steel are widely adopted in high temperature structures of.power generations, chemical processing plants and petroleum ref.neries. In this work, a total of.10000 hour tensile creep test on 16 specimens of.such two materials was conducted at 550℃. On the basis of.the experimental results, the isochronous stress-strain curves and time-dependent f.ilure assessment curves of.the two materials were given. f.nally, the f.rmulae of.time dependent f.ilure assessment curve f.r 10crMo910 and 316 stainless steel corresponding to long-term creep cases, which could be utilized in the high temperature def.cts assessment, were established. The procedure f.r def.ning the time-dependent f.ilure assessment curves was also presented.

关键词： 10crMo910 316 stainless steel creep time-dependent f.ilure assessment curve

BRIGHT LONG Af.ERGLOW PHOSPHOREScENcE GLASS MAdE Of.SrAl_(2)O_(4): Eu^(2+), dy^(3+) ANd GLASS f.ITS

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Acta Metallurgica Sinica(English Letters) 2005年第6期18卷 736-740页

作者： X. y. Zhang Z. f. cao L.P. Lu Z.H. Bai W.Z. Wang X. c. Wang department of.Materials Science and Engineering Changchun University of Science and Technology Changchun 130022 China

Bright long af.erglow phosphorescence glasses were prepared by using SrAl2O4： Eu^2＋, dy^3＋ phosphors and suitable glass f.its together. The SrAl2O4： Eu^2＋, dy^3＋ phosphors were initially prepared by the solid reaction method. Three kinds of.glass f.its were prepared to match the SrAl2O4： Eu^2＋, dy^3＋ phosphors. Ef.ects of.the compositions of.the glass f.its, the ratios of.the phosphors to the f.its us well us the f.ring temperature and f.ring times on the properties of.the samples were discussed. XRd analysis indicated the samples exhibited the typical dif.raction peaks of.SrAlwO4： Eu^2＋, dy^3＋. The emission spectra of.the samples showed broad bands peaking at *** excitation spectra of.the samples showed broad bands ranging f.om 300 to 480hm. These are believed due to the 5d4f.4f.transitions of.Eu^2＋ in the SrAl2O4： Eu^2＋, dy^3＋ phosphors. The af.erglow luminescence of.the samples excited by a 40W f.uorescence lamp f.r 30min can be observed in the dark f.r more lOh with the naked eyes. It can f.nd wide applications in many f.elds.

关键词： long af.erglow phosphorescence glass StAl2O4 :Eu^2+ dy^3+,glass f.it

Superb Strengthening Ef.ect of.Net-Like distributed Amorphous Al_(2)O_(3)on creep Resistance of.B_(4)c+Al_(2)O_(3))/Al Neutron-Absorbing Materials

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Acta Metallurgica Sinica(English Letters) 2022年第12期35卷 2007-2013页

作者： y.N.Zan X.Lei J.f.Zhang d.Wang Q.Z.Wang B.L.Xiao Z.y.Ma Key Laboratory of.Nuclear Materials and Saf.ty Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Shi-changxu Innovation center f.r Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Nuclear Equipment division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.LtdBejing 100840China

B4c reinf.rced Al composites are widely used as neutron absorbing materials(NAMs)due to excellent neutron absorbing ef.iciency,however,such NAMs exhibit poor high-temperature *** meet the requirement f.r structure-f.nction integration,NAMs with enhanced high-temperature mechanical properties are *** this work,a novel(B4 c+Al_(2)O_(3))/Al NAM with netlike distribution of.Al_(2)O_(3)was f.bricated by powder metallurgy method and subjected to high-temperature tensile creep *** was shown that the creep resistance was enhanced by several orders of.magnitude via the addition of.only2.1 vol.%netlike-distributed Al_(2)O_(3).(B_(4)c+Al_(2)O_(3))/Al exhibited high apparent stress exponents ranging f.om 16 to 25 and high apparent activation energy of.364 kJ/*** creep behaviour could be rationalized using the substructure-invariant model and its rupture behaviour could be described by the dobes-Milicka equation.

关键词： Neutron absorber material Al matrix composite Tensile creep B_(4)c/Al