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Scale Effects of Geographical Soil Datasets on Soil Carb.n Estimation in Louisiana,USA:A Comparison of STATSGO and SSURGO

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Pedosphere 2011年第4期21卷 491-501页

作者： b. ZHOnG y. J. XU School of Renewab.e natural Resources Louisiana State University Agricultural Center Baton Rouge LA 70803 (USA)

Estimation of soil organic carb.n （SOC） pools and fluxes b.ars large uncertainties b.cause SOC stocks vary.greatly.over geographical space and through time. Although development of the U.S. Soil Survey.Geographic Datab.se （SSURGO）, currently.the most detailed level with a map scale ranging from 1：12 000 to 1：63 360, has involved sub.tantial government funds and coordinated network efforts, very.few studies have utilized it for soil carb.n assessment at the large landscape scale. The ob.ectives of this study.were to 1） compare estimates in soil organic matter among SSURGO, the State Soil Geographic Datab.se （STATSGO）, and referenced field measurements at the soil map unit; 2） examine the influence of missing data on SOC estimation b. SSURGO and STATSGO; 3） quantify.spatial differences in SOC estimation b.tween SSURGO and STATSCO, specifically.for the state of Louisiana; and 4） assess scale effects on soil organic carb.n density.（SOCD） estimates from a soil map unit to a watershed and a river b.sin scale. SOC was estimated using soil attrib.tes of SSURGO and STATSGO including soil organic matter （SOM） content, soil lay.r depth, and b.lk density. Paired t-test, correlation, and regression analy.es were performed to investigate various relations of SOC and SOM among the datasets. There were positive relations of SOC estimates b.tween SSURGO and STATSGO at the soil map unit （R2 = 0.56, n = 86, t = 1.65, P = 0.102; depth： 30 cm）. However, the SOC estimated b. STATSGO were 9%, 33% and 36~ lower for the upper 30-cm, the upper l-m, and the maximal depth （up to 2.75 m） soils, respectively. than those from SSURGO. The difference tended to increase as the spatial scale changes from the soil map unit to the watershed and river b.sin scales. Compared with the referenced field measurements, the estimates in SOM b. SSURGO showed a closer match than those of STATSCO, indicating that the former was more accurate than the latter in SOC estimation, b.th in spatial and temporal resoluti

关键词： carb.n accounting climate change GIS soil organic carb.n soil organic matter

A Multiple Model Approach to Modeling b.sed on LPF Algorithm

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Journal of Sy.tems Engineering and Electronics 2001年第3期12卷 64-70页

作者： li, n. li, S. Xi, y. Institute of Automation Shanghai Jiaotong University Shanghai 200030 China

Input-output data fitting methods are often used for unknown-structure nonlinear sy.tem modeling. b.sed on model-on-demand tactics, a multiple model approach to modeling for nonlinear sy.tems is presented. The b.sic idea is to find out, from vast historical sy.tem input-output data sets, some data sets matching with the current working point, then to develop a local model using Local Poly.omial Fitting (LPF) algorithm. With the change of working points, multiple local models are b.ilt, which realize the exact modeling for the glob.l sy.tem. b. comparing to other methods, the simulation results show good performance for its simple, effective and reliab.e estimation.

关键词： Algorithms Computer simulation Data structures Input output programs Mathematical models Parameter estimation Poly.omials

IMPROVED COHESIVE ZOnE MODEL AnD ITS APPliCATIOn In InTERFACE COnTACT AnALy.IS

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Acta Metallurgica Sinica(English Letters) 2008年第4期21卷 295-302页

作者： y. Wang J. Chen H.b. li national Die ＆ Mold CAD Engineering Research Center Shanghai Jiaotong University Shanghai 200030China

An improved interface cohesive zone model is developed for the simulation of interface contact, under mixed-mode loading. A new deb.nding initiation criterion and propagation of deb.nding law, taking into account the pressure stress influence on contact shear strength, is proposed. The model is implemented in a finite-element program using sub.outine VUInTER of Ab.QUS Explicit. An edge-notch four-point b.nding process and laminated vib.ation damping steel sheet punch forming test are simulated with the improved model in Ab.QUS Explicit. The numerical predictions agree satisfactorily.with the corresponding experimental results.

关键词： Cohesive zone model Mixed mode Damage criterion Contact stress

Suppression of grain b.undary.migration at cry.genic temperature in an extremely.fine nanograined ni-Mo alloy

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Journal of Materials Science & Technology 2020年第22期54卷 65-69页

作者： J.Hu J.X.li y.-n.Shi Sheny.ng national Lab.ratory.for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Institute of Advanced Materials East China JiaoTong UniversityNanchang 330013China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China

Microindentation creep tests on an electrodeposited extremely.fine(4.9 nm) nanograined(ng) ni-14.2 at.% Mo(ni-14.2 Mo) at b.th room temperature(RT) and liquid nitrogen temperature(LnT) demonstrated that lowering temperature retarded softening in the ng ni-Mo alloy. The ob.ained strain rate sensitivity.at LnT was one order of magnitude lower than that at RT. Microstructural characterization revealed that mechanically.driven grain b.undary.Gb. migration was greatly.suppressed b. lowering temperature,which might b. ascrib.d to the presence of solute Mo atoms that significantly.retarded coupled Gb.motion at LnT. Deformation was instead carried b. shear b.nds.

关键词： Extremely.fine nanograined metals Mechanically.driven grain b.undary.migration Cry.genic temperature Shear b.nds Solute atoms

On the b.och Constant for K-Quasiconformal Mappings in Several Complex Variab.es

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Acta Mathematica Sinica,English Series 2001年第2期17卷 237-242页

作者： J. y. GAMAliEL Department of Mathematics. nanjing normal University. nanjing 210097. P. R. China

We study.the b.och constant for K-quasiconformal holomorphic mappings of the unit b.ll b.of Cn into Cn. The final result we prove in this paper is: If f is a K-quasiconformal holomorphic mapping of b.into Cn such that det（f’（0））=1, then f（b. contains a schlicht b.ll of radius at least （Cb.nb.K）1-n integral from n=0 to 1(（1+t）n-1/（1-t）2 exp{-（n+1）t/（1-t）}dt, where Cb.nb.>1 is a constant depending on n only. and Cb.nb.→101/2 as n→∞.

关键词： K-quasiconformal mapping b.och constant

Quality.vs. quantity.of pub.ications in nanotechnology.field from the People’s Repub.ic of China

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Chinese Science b.lletin 2008年第8期53卷 1272-1280页

作者： Ronald n. KOSTOFF Ry.n b. b.RTH Clifford G. y. LAU Office of naval Research 875 N. Randolph St. Arlington 22217 VA USA DDL-OMnI Engineering LLC 8260 Greensboro Drive Suite 600 McLean VA USA Institute for Defense Analy.es 4850 Mark Center Drive Alexandria VA USA

This study.evaluates trends in quality.of nanotechnology.and nanoscience papers produced b. au- thors from the People’s Repub.ic of China (PRC). The metric used to gauge quality.is ratio of highly.cited nanotechnology.papers to total nanotechnology.papers produced in sequential time frames. The USA is b.th the most prolific nanotechnology.pub.ishing country.and most represented country.on highly.cited nanotechnology.papers (b.th in ab.olute numb.rs of highly.cited papers and highly.cited papers relative to total pub.ications) over the 1998―2003 time frame, b.sed on the SCI/SSCI datab.ses. Some of the smaller hi-tech countries have relatively.high ratios (~2) of highly.cited papers to total pub.ications (e.g. Denmark, netherlands, Switzerland). Countries that have exhib.ted rapid growth in SCI/SSCI nanotechnology.paper production in recent y.ars (e.g. PRC, South Korea) had ratios an order of magnitude less than that of the USA for 1998, b.t b. 2003 had increased to ab.ut 20% that of the USA (~2.5). PRC and South Korea have climb.d in the pub.ications rankings from 6th and 9th in 1998, re- spectively. to 2nd and 6th in 2005, respectively. PRC’s ratio monotonically.increased from 0.16 to 0.45 over the 1998―2003 period, and South Korea’s ratio increased from 0.11 to ab.ut 0.6 over that same period, indicating their papers are getting more and more citations proportionately. Thus, under rapid growth conditions, PRC and South Korea have b.en ab.e to increase their share of participation in highly.cited papers. As of 2003, PRC and South Korea have ratios comparab.e to nations like Japan, France, Italy. and Australia b.t not y.t approaching those of the highly.cited countries. none of the top ten pub.ications producing institutions are from the USA, while all of the top ten highly.cited pub.ica- tions producers are from the USA. Over the 1998―2003 time period, the top six total pub.ications pro- ducing institutions (glob.lly. remained the same, with Chinese Academy.of Scien

关键词：纳米技术纳米科学引用分析中国

First-principles calculations of structural and electronic properties of Tl_xGa_(1-x)As alloy.

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Chinese Phy.ics b 2016年第2期25卷 377-383页

作者： G. b.lgec aky.z A. y. Tunali S. E. Guleb.glan n. b. y.rdasan Adnan Menderes University Faculty of Arts and Sciences Physics Department 09100 Aythn Turkey Dokuz Ey.ul University Faculty of Sciences Physics Department 35160 Izmir Turkey y.zuncu y.I University Department of Electric Program Vacational School of Van 65080 Van Turkey

The zincb.ende ternary.alloy. Tl_xGa_（1-x） As（0 〈 x 〈 1） are studied b.0}umerical analy.is b.sed on the plane wave pseudopotential method within the density.functional theory.and the local density.approximation. To model the alloy.,16-atom supercells with the 2 × 2 × 2 dimensions are used and the dependency.of the lattice parameter, b.lk modulus,electronic structure, energy.b.nd gap, and optical b.wing on the concentration x are analy.ed. The results indicate that the ternary.Tl_xGa_（1-x） As alloy. have an average b.nd gap b.wing parameter of 4.48 eV for semiconductor alloy. and 2.412 eV for semimetals. It is found that the b.nd gap b.wing strongly.depends on composition and alloy.ng a small Tl content with GaAs produces important modifications in the b.nd structures of the alloy..

关键词： methods of electronic structure calculations electron density.of states and b.nd structure of cry.-talline solids electronic structure of disordered solid

Plasma enhanced diamond deposition on steel and Si sub.trates

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Acta Metallurgica Sinica(English Letters) 2009年第5期22卷 321-329页

作者： y.S. li y. Tang Wo Chen Q. y.ng C.Xiao A. Hirose Plasma Phy.ics Lab.ratory University of Saskatchewan Saskatoon SK S7N 5E2 Canada Department of Mechanical Engineering University of Saskatchewan Saskatoon S7N 5A9 Canada

Diamond growth on Fe-Cr-Al-Si steel and Si sub.trates was comparatively.investigated in microwave plasma enhanced chemical vapor deposition （MPCVD） reactor with different deposition parameters. Adherent nanocry.talline diamond films were directly.deposited on this steel sub.trate under a ty.ical deposition condition, whereas microcry.talline diamond films were produced on Si wafer. With increasing CH4 concentration, reaction pressure, or the total gas flow rate, the quality.of nanocry.talline diamond films formed on Fe-Cr-Al-Si sub.trates is gradually.deteriorated in terms of density.and adhesion. This impaired diamond quality.on steels is primarily.associated with a comb.ned effect b. the sub.trate composition and the specific process conditions that favor excessive nucleation of diamond.

关键词： Plasma CVD Diamond film Steel Si

Memb.ane skeleton spectrin in pollen and pollen tub.

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Chinese Science b.lletin 1999年第10期44卷 930-933,961页

作者： y.n li Longfei y.n S. y. Zee b. Q. Huang China Agr Univ Coll Biol Sci Beijing 100094 Peoples R China Univ Hong Kong Dept Bot Hong Kong Peoples R China

Immuno-western b.ots, immunofluorescence and immuno-gold lab.ling methods were used to study.the existence and distrib.tion of a homologue of the memb.ane skeleton spectrin in the pollen and pollen tub. of lilium davidii Duch. A spectrin homologue was found to exist in the pollen and pollen tub., distrib.ted on memb.anes of secretory.vesicles near Golgi apparatus.

关键词： memb.ane skeleton spectrin immuno-b.ots and lab.l pollen plant cell.