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Investigation on leaching of m.lachite by citric acid

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International Journal of m.nerals,m.tallurgy and m.terials 2012年第9期19卷 782-786页

作者： m.A. Shabani m. Irannajad A.R. Azadm.hr Departm.nt of m.ning & m.tallurgical Engineering Amirkabir University of Technology P.O. Box 15875-4413 Tehran *** Iran

Leaching of an oxidized copper ore containing m.lachite, as a new approach, was investigated by an organic reagent, citric acid. Sulfuric acid is the m.st com.on reagent in the leaching of oxide copper ores, but it has several side effects such as severe adverse im.act on the environm.nt. In this investigation, the effects of particle size, acid concentration, leaching tim., solid/liquid ratio, tem.erature, and stirring speed were optim.zed. According to the experim.ntal results, m.lachite leaching by citric acid was technically feasible. Optim.m.leaching conditions were found as follows： the range of particle size, 105-150 μm. acid concentration, 0.2 m. leaching tim., 30 m.n; solid/liquid ratio, 1：20 g/m.; tem.erature, 40℃; and stirring speed, 200 r/m.n. Under the optim.m.conditions, 91.61% of copper was extracted.

关键词： m.lachite copper ore treatm.nt leaching organic acids citric acid

Packaging and degradability properties of polyvinyl alcohol/gelatin nanocom.osite film. filled water hyacinth cellulose nanocrystals

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Journal of Bioresources and Bioproducts 2021年第2期6卷 168-185页

作者： henry C.Oyeoka Chinom.o m.Ewulonu Iheom. C.Nwuzor Chizoba m.Obele Joseph T.Nwabanne Departm.nt of Polym.r and Textile Engineering Nnamdi Azikiwe UniversityP.M.B.5025AwkaNigeria Departm.nt of Chem.cal Engineering Nnamdi Azikiwe UniversityP.M.B.5025AwkaNigeria Technical Institute of Physics and Chem.stry Chinese Academy of Sciences29 Zhongguancun East RoadHaidian DistrictBeijing 100190China

Cellulose nanocrystals isolated from.water hyacinth fiber(WHF)have been studied as a reinforcem.nt for polyvinyl alcohol(PVA)-gelatin *** com.osite design was used to study and optim.ze effects of the PVA,gelatin and cellulose nanocrystal(CNC)concentration on tensile strength and elongation of form.d *** results of this study showed that WHF CNC had a diam.ter range of 20-50 nm.produced film. reaching 13.8 m.a tensile *** stability of the film. was im.roved from.380℃ to 385℃ in addition of CNCs and m.xim.m.storage m.dulus of 3 GPa were observed when 5 wt%CNC was ***,water absorption,water vapour perm.ability(WVP)and m.isture uptake of the film. decreased in addition of CNC to the PVA-gelatin *** uptake decreased from.22.50%to 19.05%while the least WVP when 10 wt%CNC added was 1.64×10^(-6)g/(m.h·Pa).These results show possibility for industrial application of WHF CNC and PVA-gelatin blends in biodegradable film. for on-the-go food wrappers.

关键词： WATER hyacinth Polyvinyl alcohol Gelatin Cellulose nanocrystals Central com.osite design Packaging film. Degradation properties

Influence of particle contact m.dels on soil response of poorly graded sand during cavity expansion in discrete elem.nt sim.lation

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Journal of Rock m.chanics and Geotechnical Engineering 2018年第6期10卷 1154-1170页

作者： Yang Dong Behzad Fatahi Hadi Khabbaz henry Zhang School of Civil and Environm.ntal Engineering University of Technology Sydney (UTS) WSP in Australia & New Zealand Sydney Office

The discrete elem.nt m.thod(DEm. has been extensively adopted to investigate m.ny com.lex geotechnical related problem. due to its capability to incorporate the discontinuous nature of granular m.terials. In particular, when sim.lating large deform.tions or distortion of soil(e.g. cavity expansion),DEm.can be very effective as other num.rical solutions m.y experience convergence problem.. Cavity expansion theory has widespread applications in geotechnical engineering, particularly to the problem. concerning in situ testing, pile installation and so forth. In addition, the behaviour of geom.terials in a m.cro-level is utterly determ.ned by m.croscopic properties, highlighting the im.ortance of contact m.dels. Despite the fact that there are num.rous contact m.dels proposed to m.m.c the realistic behaviour of granular m.terials, there are lack of studies on the effects of these contact m.dels on the soil ***, in this study, a series of three-dim.nsional num.rical sim.lations with different contact constitutive m.dels was conducted to sim.late the response of sandy soils during cylindrical cavity expansion. In this num.rical investigation, three contact m.dels, i.e. linear contact m.del, rolling resistance contact m.del,and Hertz contact m.del, are considered. It should be noted that the form.r two m.dels are linear based m.dels, providing linearly elastic and frictional plasticity behaviours, whereas the latter one consists of nonlinear form.lation based on an approxim.tion of the theory of m.ndlin and Deresiewicz. To exam.ne the effects of these contact m.dels, several cylindrical cavities were created and expanded gradually from.an initial radius of 0.055 m.to a final radius of 0.1 m. The num.rical predictions confirm.that the calibrated contact m.dels produced sim.lar results regarding the variations of cavity pressure, radial stress, deviatoric stress, volum.tric strain, as well as the soil radial displacem.nt. However, the linear contact m.del m.y resu

关键词： Discrete elem.nt m.thod(DEm. Cavity expansion Contact m.dels Behaviour of geom.terials

Applicability of sem.-destructive m.thod to derive allom.tric m.del for estim.ting aboveground biom.ss and carbon stock in the Hill zone of Bangladesh

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Journal of Forestry Research 2020年第4期31卷 1235-1245页

作者： Hossain m.hm.od m.ham.ad Raqibul Hasan Siddique S.m.Zahirul Islam.S.m.Rubaiot Abdullah henry m.tieu m..Zaheer Iqbal m.riam.Akhter Forestry and Wood Technology Discipline Khulna UniversityKhulna 9208Bangladesh Forest Inventory Division Bangladesh Forest Research InstituteChittagong 4000Bangladesh Food and Agriculture Organization Rome 00153Italy Bangladesh Forest Departm.nt Bana bhabanAgargaonDhaka 1207Bangladesh

Biom.ss estim.tion using allom.tric m.dels is a nondestructive and popular *** of an allom.tric m.del can influence the accuracy of biom.ss *** Forest Departm.nt initiated a nationwide forest inventory to assess biom.ss and carbon stocks in trees and *** relationship between carbon storage and sequestration in a forest has im.lications for clim.te change m.tigation in term. of the carbon sink in *** part of the national forest inventory,we aim.d to derive m.lti-species biom.ss m.dels for the hill zone of Bangladesh and to determ.ne the carbon concentration in tree com.onents(leaves,branches,bark and stem..In total,175 trees of 14 species were sam.led and a sem.-destructive m.thod was used to develop a biom.ss m.del,which included developm.nt of sm.ller branch(base diam.biom.ss allom.try and volum. estim.tion of bigger branches and *** best m.del of leaf,branches,and bark showed lower values for adjusted R2(0.3152-0.8043)and m.del efficiency(0.436-0.643),hence these m.dels were not recom.ended to estim.te *** best fit m.del of stem.and total aboveground biom.ss(TAGB)showed higher m.del efficiency 0.948 and 0.837,respectively,and this m.del was recom.ended for estim.tion of tree biom.ss for the hill zone of *** best fit allom.tric biom.ss m.del for stem.was Ln(Stem.=-10.7248+1.6094*Ln(D)+1.323*Ln(H)+1.1469*Ln(W);the best fit m.del for TAGB was Ln(TAGB)=-6.6937+0.809*Ln(D^2*H*W),where DBH=Diam.ter at Breast Height,H=Total Height,W=Wood *** two m.st frequently used pan-tropical biom.ss m.dels showed lower m.del efficiency(0.667 to 0.697)com.ared to our derived TAGB *** best fit TAGB m.del proved applicable for accurate estim.tion of TAGB for the hill zone of *** concentration varied significantly(pm.

关键词： Allom.try Bangladesh Biom.ss Carbon Forest inventory

Hom. location inference from.sparse and noisy data:m.dels and applications

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Frontiers of Inform.tion Technology & Electronic Engineering 2016年第5期17卷 389-402页

作者： Tian-ran HU Jie-bo LUO henry KAUTZ Adam.SADILEK Com.uter Science Departm.nt University of Rochester

Accurate hom. location is increasingly im.ortant for urban com.uting. Existing m.thods either rely on continuous(and expensive) Global Positioning System.GPS) data or suffer from.poor accuracy. In particular, the sparse and noisy nature of social m.dia data poses serious challenges in pinpointing where people live at scale. We revisit this research topic and infer hom. location within 100 m.100 m.squares at 70% accuracy for 76% and 71%of active users in New York City and the Bay Area, respectively. To the best of our knowledge, this is the first tim. hom. location has been detected at such a fine granularity using sparse and noisy data. Since people spend a large portion of their tim. at hom., our m.del enables novel applications. As an exam.le, we focus on m.deling people's health at scale by linking their hom. locations with publicly available statistics, such as education disparity. Results in m.ltiple geographic regions dem.nstrate both the effectiveness and added value of our hom. localization m.thod and reveal insights that eluded earlier studies. In addition, we are able to discover the real buzz in the com.unities where people live.

关键词： Hom. location m.bility patterns Healthcare

间断或持续PTH刺激对骨及间充质干细胞的不同分化作用

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中华医学杂志 2018年第10期98卷 781-787页

作者：张瀶曦 Deepak H. Balani Sophia Trinh henry m. Kronenberg 母义明解放军总医院内分泌科北京100853 Endocrine Unit Massachusetts General Hospital and Harvard Medical School Boston 02114 USA

目的探讨不同甲状旁腺素（PTH）给药情况下及撤药后，骨及间充质干细胞的不同分化作用机制。方法6周龄雄性C57/BL6J小鼠，基因型为SOX9－creERT/Td－Tom.to/Osteocalcin－GFP，分为间断PTH刺激及撤药组（PTH 500 μg·kg^－1·d^－1，... 详细信息

目的探讨不同甲状旁腺素（PTH）给药情况下及撤药后，骨及间充质干细胞的不同分化作用机制。方法6周龄雄性C57/BL6J小鼠，基因型为SOX9－creERT/Td－Tom.to/Osteocalcin－GFP，分为间断PTH刺激及撤药组（PTH 500 μg·kg^－1·d^－1，皮下注射）、持续PTH刺激及撤药组（PTH泵，80 μg·kg^－1·d^－1，速度0.25 μl/h，皮下埋入）、空白对照组及撤药对照组，共6组，每组8只。分别于给药2周及撤药2周时观察小鼠血清中钙离子浓度及骨密度，并取小鼠胫骨骨骼分别进行病理及免疫荧光染色。结果间断PTH刺激组血清钙离子浓度一过性升高，达（1.36±0.03）m.ol/L。持续PTH泵刺激组血清中钙离子浓度逐渐升高，48 h达高峰[（2.33±0.03）m.ol/L]，2周后恢复正常（1.12～1.27 m.ol/L）。PTH刺激2周后，间断组[（0.047±0.002）g/cm.]和持续组[（0.046±0.001）g/cm.]骨密度均高于对照组[（0.044±0.001）g/cm.]，但间断组和持续组差异无统计学意义。停药2周后，三组间Bm.差异无统计学意义。股骨病理可见间断组骨皮质不明显，大量的骨小梁增生，伴少量纤维组织增生；持续PTH刺激大片纤维组织增生，尤以骨皮质内侧显著，撤药后纤维化消失。间断PTH刺激后骨细胞和成骨细胞明显升高，撤药后明显下降；衬里细胞数量骤减，撤药后有所增加；破骨细胞给药及撤药后差异均无统计学意义。持续PTH刺激破骨细胞增多，衬里细胞骤减，撤药后破骨细胞和衬里细胞增加，成骨细胞减少。腓骨干骺端免疫荧光显示，间断PTH刺激组大量未分化的Td－tom.to间充质干细胞，撤药后较前明显减少。持续PTH组少量未分化的Td－tom.to间充质干细胞增生，撤药后较前减少。结论间断PTH刺激可通过增加未分化的间充质干细胞和成骨细胞数量，将衬里细胞转换为骨细胞和成骨细胞，进而促进骨生成；持续PTH刺激可使少量未分化的间充质干细胞、成骨细胞和骨细胞增生，伴大量纤维化增生和破骨细胞数量骤增，最终可能导致代谢性骨病，撤药后衬里细胞明显增加，或有利于代谢性骨病的缓解。

关键词：甲状旁腺素间充质干细胞骨成骨细胞破骨细胞

A world of art 2nd ed.

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A world of art

Direct sm.lting process for stainless steel crude alloy recovery from.m.xed low-grade chrom.te, nickel laterite and m.nganese ores

1997年

作者： Sayre henry m.

来源：畅想之星图书光盘版（南... 评论

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Journal of Iron and Steel Research International 2018年第5期25卷 515-523页

作者： Rom.e D. Laranjo Nathaniel m. Anacleto College of Engineering Jose Rizal Memorial State University Dapitan City Philippines m.tallurgical Ceramics and Mining Engineering Department College of Engineering MSU-Iligan Institute of Technology Iligan City Philippines

Stainless steel crude alloy recovery from.direct sm.lting of low-grade chrom.te, nickel laterite and m.nganese ores was investigated. The m.xed low-grade ores were directly sm.lted in an elevator furnace at sm.lting tem.eratures ranging from.1550 to 1600 ℃. Sm.lting experim.nts were conducted in a laboratory elevator furnace equipped with 8 U-shaped high- quality m.lybdenum.disilicide heating elem.nts. A low-grade coal was used as the reductant. Experim.ntal results showed that the recovery of Fe, Cr, Ni, m. and Si within the alloy increased from.34.22, 60.27, 57.14, 25.42 and 13.02% to 69.91, 99.26, 86.02, 60.8 and 34.21%, respectively, when the tem.erature was increased from.1550 to 1600 ℃. There was a general increase in the total recoveries of Fe, Cr, and Ni in the alloy with CaO addition increasing from.0.4 g up to 1.2 g. However, the recoveries of m. and Si vividly decreased as the CaO contents were increased. In general, the recoveries of the m.tal contents of the crude alloy increase with the increase in the am.unt of m.nganese ore. Com.ared to the recoveries of Fe, Cr, and Ni when CaO was added, the recoveries of Fe, Cr and Ni were lower when m.nganese ore was used as an additive.

关键词： Direct sm.lting · Flux · Nickel laterite ore · Chrom.te ore ·m.nganese ore · Reductant · Low-grade coal ·Stainless steel crude alloy

Study of Iron ore Processing Technology of Tam.r Gol Deposit in m.ngolia

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Journal of m.nerals and m.terials Characterization and Engineering 2024年第3期12卷 165-188页

作者： m.ngal Delgerm.a Lkhagva Byam.adorj Ayurzana Purevdorj Departm.nt of m.tallurgy and Production Engineering School of Mechanical Engineering and Transportation MUST Ulaanbaatar Mongolia Beren m.tal Co. Ltd. Beren Grup Ulaanbaatar Mongolia Foundry Workshop Repair Mechanic Plant Erdenet Factory Erdenet Mongolia

Iron ore processing for steel production is crucial to the developm.nt and econom. of m.ngolia. Regardless of having abundant natural resources and raw m.terials, m.ngolia alm.st doesn’t produce final products. So far, m.st m.ning and m.neral beneficiation plants export raw m.terials only subjected to beneficiation process. Out of m.0} than 200 deposits in m.ngolia, 91 deposits had been explored with different m.thods and stages, and estim.ted the resource of 33 reserves. Without processing the iron ore, it is im.ossible to use it for steelm.king due to its high sulfur and phosphorus im.urities. Therefore, to study the processing of iron ore deposits in m.ngolia, we did a prelim.nary investigation of iron ore deposits and took sam.les from.the Tam.r Gol deposit with high silica and phosphorus content that is difficult to process. Then, conducted m.neral analysis and determ.ned the grain structure and beneficiation characteristics of Tam.r Gol iron deposit. .

关键词： Resource ore Structure Reserve Analysis Com.osition