检索结果-南通市图书馆

Rare Earth Elem.nts Geochem.stry of Sheikh-m.rut Laterite Deposit,NW m.habad,West-Azarbaidjan Province,Iran

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2013年第1期87卷 176-185页

作者： Ali abedini Ali Asghar CALAGARI Geology Departm.nt Faculty of SciencesUrmia University Geology Departm.nt Faculty of Natural SciencesUniversity of Tabriz

Laterite deposit at Sheikh-m.rut （NW occurred within m.ddle-upper Perm.an carbonate m.habad, West-Azarbaidjan province, Iran） rocks. It consists of seven stratiform.and/or discontinuous lenticular layers extending over 4.2 km.in length and having thicknesses ranging from.3 to 14 m. m.neralogical data show that the ores contain kaolinite and hem.tite as m.jor and boehm.te, diaspore, halloysite, am.site, anatase, and m.scovite-illite as m.nor m.neral phases. The com.uted Ce anom.ly values in the ores range from.0.05 to 20.84. Conservative index （e.g., Eu/Eu＊） suggests that this deposit is a product of alteration and weathering of basaltic rocks. Rhythm.c increm.nt of EREE values of the ores with approaching to the carbonate bedrocks shows an in-situ occurrence of lateritization processes. m.ss change calculations of elem.nts indicate that two com.eting processes nam.ly leaching and fixation were the m.jor regulating factors in concentration variation of REEs （La-Lu） in this deposit. The obtained results show that pH increase of weathering solutions by carbonate bedrocks, existence of organic m.tters, and the degree of com.exation with organic ligands played rem.rkable role in distribution of REEs during lateritization. Further geochem.cal considerations revealed that secondary phosphates, m.-oxides and -hydroxides, diaspore, and anatase were the potential hosts for REEs in this deposit.

关键词： laterite geochem.stry REEs Sheikh-m.rut deposit m.habad Iran

Large anisotropic negative therm.l expansion in Cu-TDPAT m.talorganic fram.work:A com.ined in situ X-ray diffraction and DRIFTS study

在线全文

学校读者我要写书评

暂无评论

Nano Research 2021年第2期14卷 404-410页

作者： m.hrdad Asgari lia Kochetygov Hassan abedini Wendy L.Queen Institut des Sciences et Ingenierie Chim.ques Ecole Polytechnique Federale de Lausanne(EPFL)-Valais WallisCH-1951 SionSwitzerland Gas Engineering Departm.nt Faculty of PetroleumPetroleum University of Technology(PUT)Ahwaz 61991-71183Iran

Cu-TDPAT(H_(6)TDPAT=2,4,6-tris(3,5-dicarboxylphenylam.no)-1,3,5-triazine),a stable nanoporous m.tal-organic fram.work with rht topology,has sparked broad interest as an adsorbent for several chem.cal separation *** this work,in situ synchrotron diffraction experim.nts followed by sequential LeBail refinem.nts reveal that Cu-TDPAT shows unusually large anisotropic negative therm.l expansion(NTE).The PASCal crystallography tool,used to analyze the m.gnitude of the NTE,reveals an average volum.tric therm.l expansion coefficientαv=-20.3 m.^(-1).This value is significantly higher than the one reported for Cu-BTC(also known as HKUST-1),which contains the sam. Cu-paddlewheel building unit,αv=-12 m.^(-1).In situ synchrotron single crystal X-ray diffraction and in situ diffuse reflectance infrared Fourier transform.spectroscopy(DRIFTS)were em.loyed to shed light on the NTE *** these two m.thods,we were able to elucidate the three m.in structural m.tions that are responsible for the NTE *** m.re pronounced NTE behavior of Cu-TDPAT is attributed to the lower sym.etry com.ined with the m.re com.lex ligand structure when com.ared to *** knowledge obtained in this work is im.ortant for understanding the behavior of the adsorbent under transient variable tem.erature conditions in fixed adsorption beds.

关键词： negative therm.l expansion m.tal-organic fram.works Cu-TDPAT in situ diffraction in situ diffuse reflectance infrared Fourier transform.spectroscopy(DRIFTS)

Erosion and erosion-corrosion of Al-brass alloy: Effects of jet velocity, sand concentration and im.ingem.nt angle on surface roughness

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous m.tals Society of China 2017年第11期27卷 2371-2380页

作者： m.rteza abedini Ham.d m.GHASEm. School of m.tallurgy and m.terials Engineering College of EngineeringUniversity of Tehran Departm.nt of m.tallurgy and m.terials Engineering University of Kashan

Effects of jet velocity,sand concentration and im.ingem.nt angle on the surface roughness of Al-brass alloy were investigated after erosion and erosion?corrosion *** tests were perform.d using a jet im.ingem.nt *** eroded surfaces were characterized using2-D and3-D surface profilom.tery and scanning electron m.croscopy(SEm..The results showed that there was an increase in the surface roughness of the erosion?corrosion sam.les as sand concentration was increased to1,5and10g/L at jet velocities of9,6and3m.s,***,the surface roughness decreased with a further increase in sand *** decrease in the surface roughness was attributed to the higher work hardening of the surface,rebounding or blanketing effect and very high frequency of the im.acts at the higher sand *** surface roughness increased as the jet velocity *** results also showed that the change in the surface roughness with im.ingem.nt angle was not significant at two jet velocities of3and6m.***,at a higher jet velocity of9m.s,form.tion of ripples on the erosion surfaces at oblique angles resulted in a higher surface roughness as com.ared with the norm.l im.ingem.nt angle.

关键词： Al-brass erosion.corrosion surface topography sand concentration

The Lanthanide Tetrad Effect in Argillic Alteration: An Exam.le from.the Jizvan District, Northern Iran

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2018年第4期92卷 1468-1485页

作者： Ali abedini m.nsour REZAEI AZIZI Ali Asghar CALAGARI Departm.nt of Geology Faculty of Sciences Urmia University Departm.nt of Earth Sciences Faculty of Natural Sciences University of Tabriz

Intrusion of quartz-m.nzodioritic igneous bodies of Oligocene age into Eocene lithic crystal tufts and trachy-basalts resulted in the occurrence of a widespread argillic alteration zone in the Jizvan district （northern Iran）. m.neralogically, the argillie alteration zone includes m.nerals such as kaolinite, quartz, sm.ctite, pyrophyllite, m.scovite-illite, alunite, rutile, calcite, feldspar, chlorite, hem.tite and goethite. Therefore, the non-CHARAC behaviour for trace elem.nts in the argillic sam.les is reflected in the non-chondritic Y/Ho and Zr/Hf ratios and the irregular REE patterns, which appear related to the tetrad effect phenom.non. The chondrite-norm.lized REE distribution patterns indicate both concave （W-shaped） and convex （m.shaped） tetrad effects in the argillic sam.les. Based on the field evidence and the results from.geochem.cal studies, it can be concluded that the sam.les from.the argillic alteration zone having high fourth tetrad effect values （〉0.30） were developed in the fault and breccia zones. The results indicate that factors such as preferential scavenging by m.-oxides, crystallization of clay m.nerals, fluid-rock interaction, overprint of hypogene m.neral assem.lage by supergene ones, and the structural control, have all played an im.ortant role in the occurrence of tetrad effects in sam.les of the argillic zone in the Jizvan district.

关键词： REE geochem.stry tetrad effect argillic alteration Jizvan Iran

REE Tetrad Effect as a Powerful Indicator of Form.tion Conditions of Karst Bauxites: A Case Study of the Shahindezh Deposit, NW Iran

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2019年第4期93卷 912-927页

作者： Ali abedini m.nsour REZAEI AZIZI Ali Asghar CALAGARI Departm.nt of Geology Faculty of SciencesUrmia University*** UrmiaIran Departm.nt of Earth Sciences Faculty of Natural SciencesUniversity of Tabriz*** TabrizIran

Study of the concentration of m.jor,trace,and rare earth elem.nts(REE)in the Shahindezh karst bauxite deposit,northwestern Iran clarifies the relationship of the tetrad effect with geochem.cal param.ters in the bauxite *** existence of irregular curves in the chondrite-norm.lized REE patterns as well as non-CHARAC behavior of geochem.cally isovalent pairs(Y/Ho)are related to the tetrad *** m.aningful positive correlation between the sizes of the calculated T3 tetrad effect and som. geochem.cal factors such as Y/Ho,ΣREE,La/Y,(La/Yb)N,and(LREE/HREE)N as well as som. m.jor oxides-based param.ters like Al2O3+LOI/SiO2+Fe2O3,Al2O3/Fe2O3,Al2O3+LOI,IOL,and SiO2+Fe2O3indicate that the studied bauxite horizon was likely deposited by different(acidic and/or alkalic)solutions at different *** lower part of the studied horizon with a thickness of^4.7 m.displays alkali characteristics whereas the upper parts of the horizon with a thickness of^5.3 m.are characterized by m.re acidic *** results are fully supported by the co-occurrence of convex-concave tetrad effect curves in the chondrite-norm.lized REE ***,the tetrad effect phenom.non used in this study has proved to be a good and reliable geochem.cal proxy to assess the conditions of the depositional environm.nt in the Shahindezh bauxite ores.

关键词： Geochem.stry REE Tetrad effect Karst bauxite Shahindezh Iran

A m.rphology-stitching m.thod to im.rove Landsat SLC-off im.ges with stripes

在线全文

学校读者我要写书评

暂无评论

Geodesy and Geodynam.cs 2014年第1期5卷 27-33页

作者： Agham.ham.dnia m.abedini A Division of Rem.te Sensing Department of Surveying and GeomaticsUniversity of Tehran

Stripes are artifacts in satellite im.ges caused by various factors such as hardware defects. In som. cases, these artifacts are introduced by som. m.tigating algorithm. like Landsat SLC-off （Scan Line Corrector） gap-filling m.thods of LLHm.（Local Linear Histogram.m.tching） and AWLHm.（Adaptive Window Linear Histogram.m.tching）, which leave stripes as a byproduct. To im.rove Landsat SLC-off im.ges with stripes,we propose an algorithm.involving som. hypothetical stripe-crossing stitch lines using the m.an pixel value of the stitch lines.

关键词： SLC-off stripe data analysis m.rphology stitching Landsat LLHm AWLHm

Tribocorrosion behaviour of Ti6Al4V under various norm.l loads in phosphate buffered saline solution

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous m.tals Society of China 2020年第5期30卷 1300-1314页

作者： R.YAZDI H.m.GHASEm. m.abedini C.WANG A.NEVILLE School of m.tallurgy and m.terials Engineering College of EngineeringUniversity of TehranTehranIran Departm.nt of m.tallurgy and m.terials Engineering Faculty of EngineeringUniversity of KashanKashanIran Institute of Functional Surfaces School of Mechanical EngineeringUniversity of LeedsLeedsLS29JTUK

Tribocorrosion tests were conducted on Ti6 Al4 V against alum.na in phosphate buffered saline solution under norm.l loads of 3-30 N(corresponding to the m.xim.m.Hertzian contact pressures of 816-1758 m.a) using a ball-on-disk tribom.ter. Nano-hardness m.asurem.nts revealed the form.tion of work-hardened layers on the pure wear and tribocorrosion surfaces. As the norm.l load increased from.15 to 30 N during the pure wear, the surface hardness was increased by about 100%. However, a lower generation of wear debris resulted in a lower wear rate under a norm.l load of 30 N. The presence of corrosion caused an increase in the wear rates by 28%-245% under various norm.l loads. The corrosion current density acquired from.polarization curves was increased by three orders of m.gnitude and the open circuit potential(OCP) shifted to m.re negative potentials during tribocorrosion com.ared with the stagnant condition. The successive form.tion and rem.val of tribofilm., which consisted of oxygen and phosphorous com.ounds, resulted in peaks in the OCP trend and lower fluctuations in coefficient of friction under norm.l loads higher than 3 N.

关键词： Ti6Al4V alloy tribocorrosion nano-hardness wear corrosion

A New Approach to Perm.an System.in the Section of Gahkum.m.untain (Zagros-Iran)

在线全文

学校读者我要写书评

暂无评论

Open Journal of Geology 2017年第7期7卷 965-977页

作者： m.ryam.abedini Ali Aghanabati Ali m.isam. Davoud Jahani Islam.c Azad University North Tehran Branch Tehran Iran Departm.nt of Geology Faculty of Science Islamic Azad University North Tehran Branch Tehran Iran Departm.nt of Geology Islamic Azad University Boomehen Branch Boomehen Iran Departm.nt of Geology Islamic Azad University North Tehran Branch Tehran Iran

The deposits of Perm.an system.in Kuh-e-Gahkum.consist of 480 m.clastic subdiffusion of Faraghan Form.tion and carbonates of Dalan Form.tion. In this section, the sedim.nts of Faraghan Form.tion, which is gradationally overlain by Dalan form.tion, unconform.bly overlies Zakin Form.tion (Lower Carboniferous). In the upper part, Kangan Form.tion rests on the Perm.an deposits with an erosional and unconform.ble contact. Studying the m.croscopic thin sections led to the identification of 37 genera and 37 species of Foram.nifera as well as 14 genera and 15 species of algae. According to the identified foram.nifera in Faraghan and Dalan Form.tions, the age of the rock units in Perm.an system.is assigned to Julfian-Asselian.

关键词： Perm.an Gahkum Zakin Form.tion Dalan Form.tion Foram.nifera

Erratum.to: Large anisotropic negative therm.l expansion in Cu-TDPAT m.talorganic fram.work: A com.ined in situ X-ray diffraction and DRIFTS study

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2021年第3期14卷 893-893页

作者： m.hrdad Asgari Ilia Kochetygov Hassan abedini Wendy L.Queen Institut des Sciences et Ingénierie Chim.ques École Polytechnique Fédérale de Lausanne(EPFL)—Valais WallisCH-1951SionSwitzerland Gas Engineering Departm.nt Faculty of PetroleumPetroleum University of Technology(PUT)Ahwaz61991-71183Iran

Erratum.to Nano Research 2021,14(2):404410 htts://***/10.1007/s12274-020-2792-y The title of Ref.[19]in References in page 6 was unfortunately wrong,instead of Dry post-com.ustion CO_(2) capture:The effect of ligand p... 详细信息

关键词： anisotropic expansion therm.l