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Effect of dissolved-oxygen on the flotation behavior of pyrite at high altitude area

International Journal of minerals,metallurgy and materials 2024年第10期31卷 2148-2158页

作者： Yan miao Guangke ye Guofan Zhang School of minerals Processing and Bio-engineering Central South UniversityChangsha 410083China

With the continuous development of mineral resources to high altitude areas,the study of sulfide ore flotation in unconventional systems has been *** is a consensus that moderate oxidation of sulfide ore is beneficial to flotation,but the specific suitable dissolved oxygen value is inconclusive,and there are few studies on sulfide ore flotation under low dissolved oxygen environment at high *** this paper,we designed and assembled an atmosphere simulation flotation equipment to simulate the flotation of pyrite at high altitude by controlling the partial pressure of n_(2)/O_(2) and dissolved oxygen under atmospheric conditions.X-ray photoelectron spec-troscopy(XPS),atomic force microscope(AFm),Fourier transform infrared spectrometer(Ft-IR),UV-vis spectrophotometer,zeta po-tential,and contact angle measurements were used to reveal the effects of surface oxidation and agent adsorption on pyrite at high altitude(4600 m dissolved oxygen(DO)=4.0 mg/L).the results of pure mineral flotation indicated that the high altitude and low dissolved oxy-gen environment is favorable for pyrite *** angle measurements and XPS analysis showed that the high altitude atmosphere nslows down the oxidation of pyrite surface,facilitates S_(n)^(2-)/S^(0) production and enhances surface *** calcula-tions and zeta potential analysis showed that the influence of atmosphere on the form of pyrite adsorption is small,and the different atmo-spheric conditions are consistent with dixanthogen electrochemical adsorption,with lower Zeta potential under high altitude atmosphere and significant potential shift after sodium isobutyl xanthate(SIBX)*** results of Ft-IR,UV-vis,and AFm analysis showed that SIBX adsorbed more on the surface of pyrite under high altitude atmosphere and adsorbed on the surface in a mesh structure com-posed of column/*** results of the experimental study revealed the reasons for the easy flotation of sul

关键词： high altitude dissolved-oxygen pyrite flotation oxidation

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Enhancing blocking temperature using inverse hydrogen bonds for non-radical bridged dimeric Dy(Ⅲ)single-molecule magnets

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Science China Chemistry 2024年第10期67卷 3328-3338页

作者： Peng-Bo Jin Qian-Cheng Luo ye-ye Liu Yan-Zhen Zheng Frontier Institute of Science and technology State Key Laboratory of Electrical Insulation and Power EquipmentMOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterXi’an Key Laboratory of Electronic Devices and Material Chemistry and School of ChemistryXi’an Jiaotong UniversityXi’an 710054China

Single-molecule magnets(Smms)are a kind of nanosized magnetic materials that are capable of storing massive bytes of *** coupling the spin centers in a proper manner is a usual approach to promote the working temperature(or blocking temperature)for *** delocalized radicals have been widely employed to accomplish this ***,we show a new manner by using weak but multiple B–H^(δ-)···Dy^(3+)inverse hydrogen bonding(IHB)interactions to control the magnetic couplings in a series of dimeric dysprosiacaborane *** approach leads to a record high t_(B)^(100s)of 10 K among non-radical bridged dimeric Smms,which is mainly ascribed to strong ferromagnetic coupling(4.38 cm^(-1))and the proper alignment of the magnetic principle axes of the adjacent dysprosium(Ⅲ)*** verifying by theoretical calculations,these results demonstrate that IHB interactions can be used to construct strong axial ferromagnetic coupling and enhancing magnetic blocking temperature for Smms.

关键词： single-molecule magnets carborane dysprosium ferromagnetic coupling inverse hydrogen bond

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A DERIVAtIVE-HILBERt OPERAtOR ACtInG FROm LOGARItHmIC BLOCH SPACES tO BERGmAn SPACES

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Acta mathematica Scientia 2024年第5期44卷 1916-1930页

作者： Shanli ye Yun XU School of Science Zhejiang University of Science and TechnologyHangzhou310023China

Letμbe a positive Borel measure on the interval[0,1).the Hankel matrix■with entriesμn,k=μn+k,whereμn=⨜[0,1)tndμ(t),induces,formally,the operator■where■is an analytic function *** characterize the measuresμfor which■is bounded(resp.,compact)operator from the logarithmic Bloch space■into the Bergman space■,where 0≤αterize the measuresμfor which■is bounded(resp.,compact)operator from the logarithmic Bloch space■into the classical Bloch space■.

关键词： derivative-Hilbert operator logarithmic Bloch space Carleson measure

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Ion heat transport in electron cyclotron resonance heated L-mode plasma on the t-10 tokamak

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Plasma Science and technology 2024年第4期26卷 52-60页

作者： V.A.KRUPIn m.R.nURGALIEV A.R.nEmEtS I.A.ZEmtSOV S.D.SUntSOV t.B.mYALtOn D.S.SERGEEV n.A.SOLOVEV D.V.SARYCHEV D.V.RYJAKOV S.n.tUGARInOV n.n.nAUmEnKO national Research Centre“Kurchatov Institute” Moscow 123182Russia Bauman moscow State technical University Moscow 105005Russia Institution“Project Center ItER” Moscow 123098Russia JSC“SOLAR” Minsk 220034Belarus

Anomalous ion heat transport is analyzed in the t-10 tokamak plasma heated with electron cyclotron resonance heating(ECRH) in second-harmonic extra-ordinary mode. Predictive modeling with empirical scaling for Ohmical heat conductivity shows that in ECRH plasmas the calculated ion temperature could be overestimated, so an increase of anomalous ion heat transport is required. to study this effect two scans are presented: over the EC resonance position and over the ECRH power. the EC resonance position varies from the high-field side to the low-field side by variation of the toroidal magnetic field. the scan over the heating power is presented with on-axis and mixed ECRH regimes. Discharges with high anomalous ion heat transport are obtained in all considered regimes. In these discharges the power balance ion heat conductivity exceeds the neoclassical level by up to 10 times. the high ion heat transport regimes are distinguished by three parameters: the ratio te/ti, the normalized electron density gradient R/■, and the ion–ion collisionality νii~*. the combination of high te/ti, high νii~*, and R/■=6-10 results in values of normalized anomalous ion heat fluxes up to 10 times higher than in the low transport scenario.

关键词： tokamak L-mode electron cyclotron resonance heating ion heat transport

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One-pot synthesis of n-doped petroleum coke-based microporous carbon for high-performance CO_(2) adsorption and supercapacitors

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Journal of Environmental Sciences 2024年第5期139卷 93-104页

作者： Wenfu Zhu Yuqin Wang Fan Yao Xiaohong Wang Haoming Zheng Guangzheng ye Hairong Cheng Junliang Wu Haomin Huang Daiqi ye School of Environment and Energy South China University of TechnologyGuangzhou 510006China national Engineering Laboratory for VOCs Pollution Control technology and Equipment Guangzhou 510006China Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control(SCUt) Guangzhou 510006China Guangdong Provincial Engineering and technology Research Centre for Environmental Risk Prevention and Emergency Disposal South China University of TechnologyGuangzhou 510006China

Waste resource utilization of petroleum coke is crucial for achieving global carbon emission ***,a series of n-doped microporous carbons were fabricated from petroleum coke using a one-pot synthesis *** as-prepared samples had a large specific surface area(up to 2512 m^(2)/g),a moderate-high n content(up to 4.82 at.%),and high population(55%)of ultra-micropores(nm).Regulating the n content and ultra-microporosity led to efficient CO_(2)adsorption and *** ambient pressure,the optimal n-doped petroleum coke-based microporous carbon exhibited the highest CO_(2)uptake of 4.25 mmol/g at 25℃ and 6.57 mmol/g at 0℃.these values are comparable or even better than those of numerous previously reported adsorbents prepared by multistep synthesis,primarily due to the existence of *** sample exhibited excellent CO_(2)/n_(2)selectivity at 25℃ owing to the abundant basic pyridinic and pyrrolic n species;and showed superior CO_(2)adsorption-desorption cycling performance,which was maintained at 97% after 10 cycles at 25℃.moreover,petroleum coke-based microporous carbon,with a considerably high specific surface area and hierarchical pore structure,exhibited excellent electrochemical performance over the n-doped sample,maintaining a favorable specific capacitance of 233.25F/g at 0.5 A/g in 6 mol/L KOH aqueous *** study provides insight into the influence of n-doping on the porous properties of petroleum coke-based ***,the as-prepared carbons were found to be promising adsorbents for CO_(2)adsorption,CO_(2)/n_(2)separation and electrochemical application.

关键词： One-pot synthesis n-doped microporous carbon CO_(2)adsorption CO_(2)/n_(2)selectivity Electrochemical performance

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Effect of(Cr,V)_(2)(C,n)on the microstructure and mechanical Properties of WC-10Co Cemented Carbides

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Journal of Wuhan University of technology(materials Science) 2024年第5期39卷 1138-1148页

作者： LI Xiangkun WAnG Lu ye Jinwen School of materials Science and Engineering Sichuan UniversityChengdu 610065China

WC-10Co cemented carbides with finer WC and narrower grain size distributions are produced by using(Cr,V)_(2)(C,n)as grain growth *** a result,with the increase of(Cr_(0.9),V_(0.1))_(2)(C,n)and(V_(0.9),Cr_(0.1))_(2)(C,n),the grains size of WC and mean free path of Co phase decrease,and adjacency of WC *** and homogenization of grains enhance the transverse rupture strength(tRS)and the ***,the deflection and bridging of cracks keep the fracture toughness at a respectable *** WC-10Co-0.6(Cr_(0.9),V_(0.1))_(2)(C,n)-0.025(V_(0.9),Cr_(0.1))_(2)(C,n)cemented carbides exhibit excellent comprehensive mechanical properties with the tRS of 4602.6 mPa,hardness of 1835 kg/mm^(2),and fracture toughness of 10.39 mPa·m^(1/2),***,the large pores are caused by excess n larger than 0.03 wt%and deteriorates the mechanical *** provide a new approach to WC-Co cemented carbides preparation with a narrow grain size distribution by adding novel grain growth inhibitors.

关键词： (Cr,V)_(2)(C,n) nutrient content WC grains size microstructure mechanical properties

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the Extension Dimension of Subcategories and Recollements of Abelian Categories

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Acta mathematica Sinica,English Series 2024年第4期40卷 1042-1058页

作者： Xin mA ye Yang PEnG Zhao Yong HUAnG College of Science Henan University of EngineeringZhengzhou 451191P.R.China Department of mathematics Nanjing UniversityNanjing 210093P.R.China

We investigate the behavior of the extension dimension of subcategories of abelian categories under ***Λ',Λ,Λ"be art in algebras such that(modΛ',mod A,modΛ")is a recollement,and let D'and D"be subcategories of modΛand modΛ"*** any n,m≥0,under some conditions,we get dimΩ^(k)(D)≤dimΩ^(n)(D')+dimΩ^(m)(D")+1,where k=max{m,n}and D is the subcategory of modΛglued by D'and D";moreover,we give a sufficient condition such that the converse inequality holds *** applications,some results for Igusa-todorov subcategories and syzygy finite sub categories are obtained.

关键词： Recollements extension dimension Igusa–todorov subcategories syzygy finite subcategories

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Evaluation of periglacial landforms and formation of soil properties on the mount Honaz,SW türkiye

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Journal of mountain Science 2024年第9期21卷 3047-3067页

作者： SERİn Soner UnCU Levent DEDE Volkan tÜRKEŞmurat Institute of Social Sciences İstanbul Universityİstanbul 34119Türkiye Department of Geography BilecikŞeyh Edebali UniversityBilecik 11234Türkiye Department of Geography Ardahan UniversityArdahan 75002Türkiye Center for Climate Change and Policy Studies Boğaziçi Universityİstanbul 34342Türkiye

the main aim of this study is to explain periglacial processes on the summits of mount Honaz(2571 m a.s.l.),define periglacial landforms,and determine the relationships between morphometric features and topographic *** circles,stony earth circles,non sorted steps,and non sorted stripes were identified on the summits of mount ***'s correlation coefficient(r)and linear regression analyses were performed by taking metric measurements from 125 periglacial landforms to describe their morphometric features(length,width,height)of periglacial landforms and explain the relationships between them and topographic factors(elevation,slope).to explain the relationships between periglacial landforms and soil properties,soil samples from 11 periglacial landforms were taken and *** landforms,which continue to develop on the summits of mount Honaz today,have been evaluated with present climate *** of soil samples indicates a notable impact of parent material on the genesis of periglacial *** high ratio of organic matter in mud circle and non sorted step landforms and the high lime ratio in stony earth circle landforms prove a strong relationship between the formation mechanisms of landforms and the soil ***,it is consistent with the findings obtained from the analysis that severe periglacial processes and washing and scavenging events are experienced more on the northern slopes.

关键词： Periglacial processes and geomorphology Soil analysis morphometric analysis mount Honaz türkiye

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Epidemiology of work-related hand and wrist injuries in a referral center: A descriptive study

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World Journal of Orthopedics 2024年第7期15卷 650-659页

作者： Angélica m Rodríguez Ginna P tocanchón Jessica t Villalba Luis m Pombo Aníbal A teherán Gabriel Camero-Ramos Karen P Ayala Gerhard m Acero Research Center Fundación Universitaria Juan N.CorpasBogotá111321Colombia Red Cross Cruz Roja Colombiana-Seccional Cundinamarca BogotáBogotá111221Colombia Vigilancia Epidemiológica Instituto Nacional de SaludBogotá111321Colombia

BACKGROUnD Occupational hand and wrist injuries(OHWIs)account for 25%of work-related accidents in low-and middle-income *** Colombia,more than 500000 occupational accidents occurred in 2021,and although the rate declined to less than 5%in 2020 and 2021,at least one in four accidents involved a hand or wrist *** to describe the OHWIs in workers seen at the emergency room at a second-level hospital in *** An observational study was performed using data from workers who experienced OHWIs and attended a second-level hospital,between June,2020 and may,*** overall frequency of OHWIs,as well as their distribution by sociodemo-graphic,clinical,and occupational variables,are ***,association patterns between sex,anatomical area(fingers,hand,wrist),and type of job were analyzed by correspondence analysis(CA).RESULtS there were 2.101 workers treated for occupational accidents,423(20.3%)were cases of OHWIs,which mainly affected men(93.9%)with a median age of 31 years and who worked mainly in mining(75.9%).OHWIs were more common in the right upper extremity(55.3%)and comprised different types of injuries,such as contusion(42.1%),laceration(27.9%),fracture(18.7%),and crush injury(15.6%).they primarily affected the phalanges(95.2%),especially those of the first finger(25.7%).the CAs showed associations between the injured anatomical area and the worker’s job that differed in men and women(explained variance>90%).COnCLUSIOn One out of five workers who suffered occupational accidents in Cundinamarca,Columbia had an OHWI,affecting mainly males employed in *** occupational profile is likely to lead to prolonged rehabilitation,and permanent functional *** results might be useful for adjusting preventive measures in cluster risk groups.

关键词： Accidents Occupational Epidemiology Hand injuries Wrist injuries Occupational health

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Low-temperature nH_(3) abatement via selective oxidation over a supported copper catalyst with high Cu^(+) abundance

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Journal of Environmental Sciences 2024年第9期143卷 12-22页

作者： Zhiming Yang Lin Peng Leneng Yang mingli Fu Daiqi ye Peirong Chen Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control National Engineering Laboratory for VOCs Pollution Control Technology and EquipmentSchool of Environment and EnergySouth China University of TechnologyGuangzhou 510006China Guangdong Chengyi Environmental technology Corp. Shaoguan 512158China

Selective catalytic nH_(3)-to-n_(2) oxidation(nH_(3)-SCO)is highly promising for abating nH_(3) emissions slipped from stationary flue gas after-treatment *** practical application,however,is limited by the non-availability of low-cost catalysts with high activity and n_(2) ***,using defect-rich nitrogen-doped carbon nanotubes(nCnt-AW)as the support,we developed a highly active and durable copper-based nH_(3)-SCO catalyst with a high abundance of cuprous(Cu^(+))*** obtained Cu/nCnt-AW catalyst demonstrated outstanding activity with a t_(50)(*** temperature to reach 50% nH_(3) conversion)of 174℃ in the nH_(3)-SCO reaction,which outperformed not only the Cu catalyst supported on n-free O-functionalized Cnts(OCnts)or nCnt with less surface defects,but also those most active Cu catalysts in open *** kinetics measurements and temperature-programmed surface reactions using nH_(3)as a probe molecule revealed that the nH_(3)-SCO reaction on Cu/nCnt-AW follows an internal selective catalytic reaction(i-SCR)route involving nitric oxide(nO)as a key *** to mechanistic investigations by X-ray photoelectron spectroscopy,Raman spectroscopy,and X-ray absorption spectroscopy,the superior nH_(3)-SCO performance of Cu/nCnt-AW originated from a synergy of surface defects and ***,surface defects promoted the anchoring of Cu O nanoparticles on n-containing sites and,thereby,enabled efficient electron transfer from n to Cu O,increasing significantly the fraction of SCR-active Cu^(+)sites in the *** study puts forward a new idea for manipulating and utilizing the interplay of defects and n-dopants on carbon surfaces to fabricate Cu^(+)-rich Cu catalysts for efficient abatement of slip nH_(3)emissions via selective oxidation.

关键词： nH_(3)-SCO XAnES Localized etching n-doping n_(2) selectivity i-SCR

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