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The Ef.ect of.NiAl Coatings on Oxidation Behavior of.AISI 403 Stainless Steel

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材料热处理学报 2004年第05B期25卷 666-670页

作者： M. Ebrahimian f. Ashraf.zadeh Iranian Surf.ce Research & Engineering Centre Isfahan Science & Technology Town Isfahan IranDepartment of Materials Engineering Isfahan University of Technology Isfahan Iran

This paper reports the oxidation behavior of.stainless steel type 403 as a substrate material with and without NiAl coating. Evaluation of.oxidation resistance was perf.rmed on uncoated and coated specimens at 850 and 1050°C. A commercial dif.usion process was used f.r the f.rmation of.NiAl intermetallic coatings on the specimens. Bef.re aluminizing, a layer of.nickel, about 40 um, was deposited on specimens by electroplating. Various techniques including SEM, EDAX, optical microscopy and micro-hardness testing were employed to investigate the coatings bef.re and af.er oxidation tests. Nickel-aluminides produced by two stage; plating-aluminizing, treatment with NiAl on the surf.ce increased the perf.rmance of.stainless steel samples signif.cantly.

关键词： NiAl涂层 AISI403不锈钢氧化热处理

Seasonal variations of.PM10 -- Trace elements, PAHs and Levoglucosan: Rural sugarcane growing area versus coastal urban area in Southeastern f.orida, USA. Part II: Elemental concentrations

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Particuology 2019年第5期17卷 99-108页

作者： Orhan Sevim oglu Wolf.ang f. Rogge Department of.Environmental Engineering Cebze Technical University Cebze Kocaeli 41400 Turkey School of.Engineering and Sierra Nevada Research Institute University of California Merced. 5200 North Lake Road Merced CA 95343 USA

The largest sugarcane-growing area in the United States is in South f.orida. An estimated 7 million tons of.dry sugarcane leaf. biomass is removed f.om the f.elds bef.re harvest by burning the leaves of. the sugarcane stalks. Preharvest sugarcane leaf.f.liage burning is a major source of.airborne particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), biogenic trace elements such as K, volatile hydrocarbons and other pollutants. In one harvesting period, approximately 22 million tons of.C02, a greenhouse gas, is released, 7 million tons f.om leaf.f.liage preharvest burning alone and 15 million tons f.om burning sugarcane bagasse in the sugar mills f.r power generation. In this study, PMio was collected f.om Belle Glade, close to the sugarcane-growing area, and f.om Delray Beach, an urbanized area along the East Coast of.f.orida. The PM samples were analyzed f.r trace elements and close to organic compounds. To elucidate the importance of.preharvest sugarcane biomass smoke emissions on air quality, 39 trace elements, 18 PAHs, and levoglucosan were selected to apportion ambient PM constituents. Al, Ca and to a great extend also Mg are the major soil-related trace elements and key markers f.r f.gitive soil dust emissions. Similarly, sea salt aerosol blown f.om the Atlantic Ocean into f.orida added appreciably to PMio trace elements concentration, especially Na and Cl. Approximately half.of.the sea salt aerosol (PMjo -portion) by mass is removed f.om the atmosphere during the transport of.ocean air f.om Delray Beach to Belle Glade. Ambient acid displacement reactions caused a substantial portion of.the Cl (30%) to be liberated f.om the sea salt aerosol to the atmosphere during transport as gaseous HC1. The PAH concentrations at Belle Glade were high when the biomass combustion markers levoglucosan and If.f.liage is burned of. just bef.re harvest, most of

关键词： Urban versus rural Trace elements Sugarcane burning Rare earth elements Sea salt aerosol Potassium Levoglucosan PAHs

Three-dimensional simulation of.long-wavelength f.ee-electron lasers with helical wiggler and ion-channel guiding

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Chinese Physics B 2013年第7期22卷 183-191页

作者： f. Jaf.ri Bahman B. Maraghechi Department of.Physics Amirkabir University of Technology

A three-dimensional simulation of.a steady-state amplif.er model of.a long-wavelength f.ee-electron laser （f.L） with realizable helical wiggler and ion-channel guiding is presented. The set of.coupled nonlinear dif.erential equations f.r electron orbits and f.elds of.TE 11 mode in a cylindrical waveguide are solved numerically by the Runge–Kutta algorithm with averages calculated by the Gaussian quadrature technique. Self.f.elds and space-charge ef.ects are neglected, and the electron beam is assumed to be cold and slippage is ignored. The parameters correspond to the Compton regime. Evolution of.the radiation power and growth rate along the wiggler is studied. Ion-channel density is chosen to obtain optimum ef.iciency. Simulations are pref.rmed f.r the f.L operating in the neighborhood of.35 GHz and 16.5 GHz f.r the electron beam energies of.250 keV and 400 keV, respectively. The result of.the saturated ef.iciency was f.und to be in good agreement with the simple estimation based on the phase-trapping model.

关键词： f.ee-electron laser helical wiggler ion-channel guiding

Approximate solutions of.Schrdinger equation f.r Eckart potential with centrif.gal term

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Chinese Physics B 2010年第9期19卷 155-160页

作者： f. Taskin G. Koak Department of.Physics Erciyes University

The approximate analytical solutions of.the Schrodinger equation f.r the Eckart potential are presented f.r the arbitrary angular momentum by using a new approximation of.the centrif.gal term. The energy eigenvalues and the corresponding wavef.nctions are obtained f.r dif.erent values of.screening parameter. The numerical examples are presented and the results are in good agreement with the values in the literature. Three special cases, i.e., s-wave, ξ= λ=1, and β=0, are investigated.

关键词： Schrodinger equation Eckart potential bound state

Stable non-synonymous substitutions on NS gene (NS1 and NS2 proteins) of.Qinghai lake H5N1 inf.uenza virus (Clade 2.2) af.er successive passages in Muscovy ducks

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Science China(Lif. Sciences) 2009年第9期52卷 847-853页

作者： GAO George f. Key Laboratory of.Pathogenic Microbiology and Immunology of.CAS (CASPMI) Institute of Microbiology Chinese Academy of Sciences (CAS) China-Japan joint Laboratory of.Molecular Immunology and Molecular Microbiology Institute of Microbiology Chinese Academy of Sciences Graduate University of.Chinese Academy of.Sciences Beijing Institutes of.Lif. Science Chinese Academy of Sciences

Although worldwide concern has been raised since the large-scale outbreak of.highly pathogenic avian inf.uenza in wild birds at Qinghai Lake,China in 2005,the f.ctors responsible f.r the ability to kill waterf.wl remain unclear. The why and how questions of.the H5N1 virus species-jump into its reservoir host need to be answered. In this report we test the pathogenicity and adaptation of.Qinghai Lake (Clade 2.2) isolate to Muscovy ducks f.r f.rther understanding of.this virus. The isolate was highly pathogenic in ducks and retained its high pathogenicity even af.er 20 generations of.passage in ducks. During the process of.serial passages,only the NS gene developed non-synonymous substitutions,which caused two mutations in NS1 protein (Val23Ala and Leu207Pro) and one in NS2 (Phe55Leu). These mutations persisted immutably through all subsequent passages and the pathogenicity remained high,implying that highly pathogenic H5N1 virus remains stable in aquatic birds through oral transmission. Although the exact f.nctions of.these mutations are not known,our results provide an important f.undation f.r f.rther understanding the characteristics of.the Qinghai Lake isolates.

关键词： avian inf.uenza virus H5N1 mutation NS1/2 serial passages

Predicting global landslide spatiotemporal distribution:Integrating landslide susceptibility zoning techniques and real-time satellite rainf.ll estimates

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International journal of.Sediment Research 2008年第3期23卷 249-257页

作者： Robert f. ADLER Senior Research Scientist Code 613.1 Laboratory for Atmospheres NASA/Goddard Space Flight Center Greenbelt MD 20771 U. S. ADr.

Landslides triggered by rainf.ll can possibly be f.reseen in real time by jointly using rainf.ll intensity-duration thresholds and inf.rmation related to land surf.ce susceptibility. However, no system exists at either a national or a global scale to monitor or detect rainf.ll conditions that may trigger landslides due to the lack of.suf.icient ground-based observing network in many parts of.the world. Recent advances in satellite remote sensing technology and increasing availability of.high-resolution geospatial products around the globe have provided an unprecedented opportunity f.r such a study. In this paper, a f.amework f.r developing a preliminary real-time prediction system to identif. where rainf.ll-triggered landslides will occur is proposed by combining two necessary components: surf.ce landslide susceptibility and a real-time space-based rainf.ll analysis system (http://***). f.rst, a global landslide susceptibility map is derived f.om a combination of.semi-static global surf.ce characteristics (digital elevation topography, slope, soil types, soil texture, land cover classif.cation, etc.) using a GIS weighted linear combination approach. Second, an adjusted empirical relationship between rainf.ll intensity-duration and landslide occurrence is used to assess landslide hazards at areas with high susceptibility. A major outcome of.this work is the availability f.r the f.rst time of.a global assessment of.landslide hazards, which is only possible because of.the utilization of.global satellite remote sensing products. This preliminary system can be updated continuously using the new satellite remote sensing products. This proposed system, if.pursued through wide interdisciplinary ef.orts as recommended herein, bears the promise to grow many local landslide hazard analyses into a global decision-making support system f.r landslide disaster preparedness and mitigation activities across the world.

关键词： Landslide Natural disasters Satellite remote sensing Real-time precipitation analysis Landslide susceptibility

Evaluation of.Metal f.tigue Problems Using Qualitative Reasoning Approach

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Tsinghua Science and Technology 2008年第S1期13卷 96-101页

作者： Siegf.ied f. Stiemer Civil Engineering Department University of British Columbia

f.tigue f.ilures are of.en encountered in steel structures under heavy cyclic loadings. This paper presents metal f.tigue problems in structural engineering using outcomes of.recent advancements in numerical qualitative reasoning. Qualitative reasoning provides an ef.ective and sound technique f.r solving complex and uncertain scenarios, regardless of.the uncertainty or linearity of.the design parameters and their constraints. This paper introduces the algorithms behind a sof.ware platf.rm, built upon numerical qualitative reasoning f.r engineering applications. The sof.ware expresses the results of.the analysis in variable ranges and diagrams showing a two-dimensional design space. The capability of.representing design parameters and outcomes in solution spaces provides a practical way f.r engineers to leverage their existing knowledge and experience. Case studies in metal f.tigue design are given to ref.ect on the capability of.qualitative reasoning in engineering applications.

关键词： computer applications conceptual design decision support system constraints qualitative reasoning f.tigue

A case f.r mantle plumes

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Chinese Science Bulletin 2005年第15期50卷 1541-1554页

作者： Geof.rey f. Davies Research School of.Earth Sciences Australian National University Canberra ACT 0200 Australia

The existence of.at least several plumes in the Earth’s mantle can be inf.rred with f.w assumptions f.om well-established observations. As well, thermal mantle plumes can be predicted f.om well-established and quanti-f.ed f.uid dynamics and a plausible assumption about the Earth’s early thermal state. Some additional important ob-servations, especially of.f.ood basalts and rif.-related mag-matism, have been shown to be plausibly consistent with the physical theory. Recent claims to have detected plumes using seismic tomography may comprise the most direct evidence f.r plumes, but plume tails are likely to be dif.icult to resolve def.nitively and the claims need to be well tested. Although signif.cant questions remain about its viability, the plume hypothesis thus seems to be well worth continued investiga-tion. Nevertheless there are many non-plate-related mag-matic phenomena whose association with plumes is unclear or unlikely. Compositional buoyancy has recently been shown potentially to substantially complicate the dynamics of.plumes, and this may lead to explanations f.r a wider range of.phenomena, including “headless” hotspot tracks, than purely thermal plumes.

关键词：地球覆盖物羽毛流体动力学热量对流火山

A simple and easy method to measure ammonia volatilization:Accuracy under f.eld conditions

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Pedosphere 2021年第2期31卷 255-264页

作者： Márcio R.MARTINS Leonardo f.SARKIS Roni f.GUARESCHI Camila A.SANTOS Selenobaldo A.C.SANT’ANNA Mohammad ZAMAN Claudia P.JANTALIA Bruno J.R.ALVES Robert M.BODDEY Ednaldo S.araÚjo Segundo URQUIAGA Embrapa Agrobiology Rod.BR 465km 7Seropédica RJ CEP 23891-000(Brazil) Agroscope Research Division Agroecology and EnvironmentClimate and Agriculture GroupReckenholzstrasse 191Zurich 8046(Switzerland) f.deral Rural University of.Rio de Janeiro(Uf.RJ) Rod.BR 465km 7Seropédica RJ CEP 23891-000(Brazil) Soil and Water Management&Crop Nutrition Joint FAO/IAEA Division of Nuclear Techniques in Food&AgricultureP.O.Box 100Vienna A-1400(Austria)

f.eld studies on soil ammonia(NH_(3))volatilization are restricted in many countries owing to the high costs commonly demanded f.r accurate *** assessed the accuracy of.a simple,open chamber design to capture NH_(3)under f.eld conditions,as af.ected by dif.erent chamber placement ***-15 N was surf.ce applied to lysimeters installed in the spaces between maize *** chambers made f.om plastic bottles were installed on each lysimeter with variations in i)N rates(3,8,13,and 18 g m^(-2)),ii)the height of.the chamber above the soil surf.ce(0,5,and 10 mm),and iii)chamber relocation(static ***).Ref.rence lysimeters without chambers were used to measure NH_(3)losses by^(15)*** of.NH_(3)-N accounted f.r more than 50%of.the applied *** of.the chambers had no impact on their NH_(3)-trapping ef.iciencies,proving to be an unnecessary *** in the height of.the chambers above the soil surf.ce af.ected the capture of.NH_(3),but the results still maintained high linearity with the NH_(3)losses quantif.ed by the ref.rence method(R^(2)>0.98).When the same placement scheme used in the introductory study describing the chamber was utilized(static and touching the soil surf.ce),we f.und a trapping ef.iciency of.60%,which was very similar to that(57%)obtained in the previous *** results show that this simple,open chamber design can be used with satisf.ctory accuracy under f.eld conditions,provided that simple,standardized procedures are warranted.

关键词： ammonia collector chamber method f.eld sampler gas emission low-cost chamber nitrogen cycling