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地理信息科学

地理译报 1993年第4期12卷 4-12页

作者： m.f.古德柴尔德章燕燕

1.引言在过去的十年中,地理信息系统(GIS)已发展到了一个较为成熟的阶段。很多国家建立了相关的研究和培训项目,新的应用领域不断被发现,新产品不断涌现,遥感平台技术的发展使得新的重要数据的获得成为可能。可以说,GIS 的研究前景,具... 详细信息

1.引言在过去的十年中,地理信息系统(GIS)已发展到了一个较为成熟的阶段。很多国家建立了相关的研究和培训项目,新的应用领域不断被发现,新产品不断涌现,遥感平台技术的发展使得新的重要数据的获得成为可能。可以说,GIS 的研究前景,具有相当的吸引力。然而,所有这些活动的目的是什么?象“空间数据处理”这样的名词可以描述我们做了些什么,但描述不了为什么我们这样做。

关键词：地理信息科学地理信息系统

Soil microbial Biomass After Three-Year Consecutive Composted Tannery Sludge Amendment

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Pedosphere 2014年第4期24卷 469-475页

作者： m.D.m.SILVA m.BARAJAS-ACEVES A.S.f.ARAúJO f.f.ARAúJO W.J.mELO Soil Quality Lab. Agricultural Science CenterFederal University of PiauiTeresinaPI 64049-550(Brazil) CINVESTAV-IPN Departamento de BiotecnologiaBioingenieriaMexico D.F.PO Box 14-740(Mexico) West Sao Paulo University UNOESTEPresidente PrudenteSP 19067-175(Brazil) Department of Technology Sao Paulo State UniversityJaboticabalSP 14801-902(Brazil)

Brazilian industry produces huge amounts of tannery sludge as residues,which is often disposed by landfilling or land ***,consecutive amendment of such composted industrial wastes may cause shifts in soil microbial biomass(SmB) and enzyme *** study aimed to evaluate SmB and enzyme activity after 3-year consecutive composted tannery sludge(CTS) amendment in tropical sandy *** amounts of CTS(0.0,2.5,5.0,10.0,and 20.0 t ha^(-1)) were applied to a sandy *** C and N contents of SmB,basal and substrate-induced respiration,respiratory quotient(qCO_2),and enzyme activities were determined in the soil samples collected after CTS amendment for 60 d at the third *** 3 years,significant changes were found in soil microbial properties in response to different CTS amounts *** organic matter and Cr contents significantly increased with increasing CTS *** and soil respiration peaked following amendment with 10.0 and 20.0 t ha-1 of CTS,respectively,while qCO_2was not significantly affected by CTS ***,soil enzyme activity decreased significantly with increasing CTS *** CTS amendment for 3 years showed inconsistent and contrasting effects on SmB and enzyme *** decrease in soil enzyme activities was proportional to a substantial increase in soil Cr concentration,with the latter exceeding the permitted concentrations by more than ***,our results suggest that a maximum CTS quantity of 5.0 t ha^(-1) can be applied annually to tropical sandy soil,without causing potential risks to SmB and enzyme activity.

关键词： Cr concentration enzyme activity industrial wastes soil microbial properties tropical soil

An empirical study on vortex-generator insert fitted in tubular heat exchangers with dilute Cu–water nanofluid flow

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Chinese Journal of Chemical Engineering 2016年第6期24卷 728-736页

作者： m. Khoshvaght-Aliabadi m.H. Akbari f. Hormozi Department of Chemical Engineering Shahrood Branch Islamic Azad University Shahrood lran School of Chemical Petroleum and Gas Engineering Semnan University Semnan lran

The heat transfer enhancement(HTE) in tubular heat exchangers fitted with vortex-generator(VG) inserts is experimentally investigated. The studied four parameters and ranges are: winglets-pitch ratio(1.33, 2.67, and 4),winglets-length ratio(0.33, 0.67, and 1), winglets-width ratio(0.2, 0.4, and 0.6), and Reynolds number(5200to 12200). The testing fluids are the water and Cu–water nanofluid at the volumetric fraction of 0.2%. The results obtained on HTE, pressure drop, and performance evaluation criterion(PEC) are compared with those for water in a smooth tube. It is found that the VG inserts with lower winglets-pitch ratio and higher winglets-length/width ratios present higher values of HTE and pressure drop. Over the range studied, the maximum PEC of 1.83 is detected with the Cu–water nanofluid inside the tube equipped with a VG insert at the winglets-width ratio of0.6 for the maximum Reynolds number, when the heat transfer rate and pressure drop are 1.24 times and 2.03 times of those in the smooth tube. Generalized regression equations of the Nusselt number, friction factor, and PEC are presented for the tubular heat exchangers with the VG inserts for both water and Cu–water *** is concluded that the main advantage of the VG inserts is their simple fabrication and considerable performance, particularly at higher Reynolds number.

关键词： Heat transfer enhancementVortex-generator insertNanofluid Turbulent flowCorrelation

Solder Size Effect on Early Stage Interfacial Intermetallic Compound Evolution in Wetting Reaction of Sn3.0Ag0.5Cu/ENEPIG Joints

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Journal of materials Science & Technology 2015年第3期31卷 252-256页

作者： m.L.Huang f.Yang Electronic Packaging materials Laboratory School of Materials Science & Engineering Dalian University of Technology

Solder size effect on early stage interfacial intermetallic compound(ImC) evolution in wetting reaction between Sne3.0Age0.5Cu solder balls and electroless nickel electroless palladium immersion gold(ENEPIG) pads at 250 C was investigated. The interfacial ImCs transformed from initial needle- and rodtype(Cu,Ni)6Sn5to dodecahedron-type(Cu,Ni)6Sn5and then to needle-type(Ni,Cu)3Sn4at the early interfacial reaction stage. moreover, these ImC transformations occurred earlier in the smaller solder joints, where the decreasing rate of Cu concentration was faster due to the Cu consumption by the formation of interfacial(Cu,Ni)6Sn5. On thermodynamics, the decrease of Cu concentration in liquid solder changed the phase equilibrium at the interface and thus resulted in the evolution of interfacial ImCs; on kinetics, larger solder joints had sufficient Cu flux toward the interface to feed the(Cu,Ni)6Sn5growth in contrast to smaller solder joints, thus resulted in the delayed ImC transformation and the formation of larger dodecahedron-type(Cu,Ni)6Sn5grains. In smaller solders, no spalling but the consumption of(Cu,Ni)6Sn5grains by the formation of(Ni,Cu)3Sn4grains occurred where smaller discrete(Cu,Ni)6Sn5grains formed at the interface.

关键词： Size effect Lead-free solder Interfacial reaction

New Exact Solutions of a Relativistic Toda Lattice System

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Chinese Physics Letters 2012年第9期29卷 53-56页

作者： m.T.Darvishi f.Khani Department of mathematics Razi UniversityKermanshah 67149Iran

We study the application of the exp-function method to solve a relativistic Toda lattice *** reduce the original equation into a convenient form,a suitable transformation is used so that the so-called exp-function method can be *** using the homogeneous balance principle and some further analysis,we succeed in calculating some exact analytic solutions.

关键词： convenient exact calculating

Aerodynamic Loading Distribution Effects on the Overall Performance of Ultra-High-Lift LP Turbine Cascades

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Journal of Thermal Science 2014年第1期23卷 1-12页

作者： m.Berrino f.Satta D.Simoni m.Ubaldi P.Zunino f.Bertini DImE Università degli Studi di Genova Via Montallegro 1I-16145 GenovaItaly Avio S.p.A. Professors I Maggio 56I-10040 Rivalta (TO) Italy

The present paper reports the results of an experimental investigation aimed at comparing aerodynamic perform- ance of three low-pressure turbine cascades for several Reynolds numbers under steady and unsteady inflows. This study is focused on finding design criteria useful to reduce both profile and secondary losses in the aero-engine LP turbine for the different flight conditions. The baseline blade cascade, characterized by a standard aerodynamic loading （Zw=1.03）, has been compared with two Ultra-High-Lift profiles with the same Zweifel number （Zw=1.3 for both cascades）, but different velocity peak positions, leading to front and mid-loaded blade cascade configurations. The aerodynamic flow fields downstream of the cascades have been experimentally in- vestigated for Reynolds numbers in the range 70000〈Re〈300000, where lower and upper limits are typical of cruise and take-off/landing conditions, respectively. The effects induced by the incoming wakes at the reduced frequency ./＋=0.62 on both profile and secondary flow losses for the three different cascade designs have been studied. Total pressure and velocity distributions have been measured by means of a miniaturized 5-hole probe in a tangential plane downstream of the cascade for both inflow conditions. The analysis of the results allows the evaluation of the aerodynamic performance of the blade cascades in terms of profile and secondary losses and the understanding of the effects of loading distribution and Zweifel number on secondary flows. When operating un- der unsteady inflow, contrarily to the steady case, the mid-loaded cascade has been found to be characterized by the lowest profile and secondary losses, making it the most attractive solution for the design of blades working in real conditions where unsteady inflow effects are present.

关键词： Low-Pressure Turbine Ultra-High-Lift Prof'des Profile Losses Secondary Losses mid-Loaded Blade Cascades Aft-Loaded Blade Cascades.

formation of AlN from Secondary Al Resources

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Journal of materials Science & Technology 2006年第5期22卷 621-624页

作者： m.Bahgat m.Radwan f.E.farghaly Central metallurgical Research and Development Institute (CmRDI) P.O.Box 87 Helwan Cairo 11421 Egypt

Synthesis of AlN by NH4Cl-assisted direct nitridation of secondary Al resources was studied. Aluminum alloy scrap contained mg and Zn element was used. milled Al scrap （-1 mm） was mixed with NH4Cl and heated at 1000℃ for 1 h in presence of 1 L/min N2 flow gas. The nitrided product was evaluated by X-ray diffraction semi-quantitative analysis and scanning electron microscopy （SEm）. Aluminium nitride of 90.5% concentration was obtained with a hexagonal crystalline form. AlN is mostly formed in nano-whisker morphology （50～150 nm） which is homogenously distributed.

关键词： AlN Direct nitridation Nanowhisker Secondary resources

Bound states of the Dirac equation with position-dependent mass for the Eckart potential

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Chinese Physics B 2013年第1期22卷 62-67页

作者： Bahar m. K. Yasuk f. Department of Physics Erciyes University Department of Physics Karamanoglu Mehmetbey University

Studying with the asymptotic iteration method, we present approximate solutions of the Dirac equation for the Eckart potential in the case of position-dependent mass. The centrifugal term is approximated by an exponen... 详细信息

关键词： Dirac equation position-dependent mass Eckart potential asymptotic iteration method

Infrared, Diffuse Reflectance and Dielectric Studies ofAntimony Trisulphide

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Journal of materials Science & Technology 1998年第4期14卷 344-348页

作者： Hanafi, Z.m. Ismail, f.m. Khalil, m.Sh. Inorganic Chemistry Dept. National Research Centre Dokki Cairo Egypt

Infrared absorption spectra of orange, black and transferred Sb//2S//3 samples have been studied in the spectral range 200-4000 cm** minus **1. The pronounced difference between the different samples is the appearance of excess sulphur present in the orange and transferred samples except those of transferred at 543 K and the black Sb//2S//3. The change of sharpness of some IR peaks reveals the amorphous/crystalline change. The effect of the degree of crystallinity and stoichiometry on the energy gap values was investigated by using optical method. The obtained dielectric parameters epsilon prime and epsilon double prime of the different samples are thoroughly affected by the degree of crystallinity and smoothly affected by either the frequency or the temperature or both, except at lower frequencies. (Edited author abstract) 26 Refs.

关键词： Antimony compounds