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Sulfidization regulation of cuprite by pre-oxidation using sodium hypochlorite as an oxidant

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International Journal of Mining Science and Technology 2021年第6期31卷 1117-1128页

作者： guang han Shuming Wen han Wang Qicheng Feng State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Faculty of Land Resources EngineeringKunming University of Science and TechnologyKunming 650093China

The direct sulfidization of cuprite is inefficient because cuprite is a copper-oxide mineral with a strong surface *** this study,oxidant was used to modify cuprite surfaces to regulate the sulfidization of *** tests showed that the flotation recovery of pre-oxidized cuprite was nearly25% higher than that of direct sulfidization flotation,which indicates that the cuprite surface activity was enhanced after pre-oxidation by Cu(Ⅰ) species(weak affinity with sulfur ions) transformation to Cu(Ⅱ)species(strong affinity with sulfur ions).Zeta potential,scanning electron microscopy-energy dispersive X-ray spectroscopy,X-ray photoelectron spectroscopy,and time-of-flight secondary ion mass spectrometry results showed that pre-oxidation improved cuprite sulfidization and promoted the formation of copper-sulfide species on the cuprite *** mineral surface stability and thus,xanthate species adsorption on the cuprite surfaces were *** surface-adsorption measurements and infrared spectroscopy showed that a large amount of xanthate species was adsorbed onto the sulfidized cuprite surfaces after pre-oxidation,which enhanced the cuprite hydrophobicity and improved the cuprite flotation.

关键词： Cuprite Pre-oxidation Enhanced sulfidization Xanthate adsorption

Unveiling pairing mechanism in quasi-one-dimensional Cr-based superconductors

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Science Bulletin 2017年第3期62卷 206-207页

作者： guang-han Cao Department of Physics Zhejiang University Hangzhou 310027 China

Superconductivity is a macroscopic quantum phenomenon in which electron pairing(or Cooper pairing)plays a crucial role for its *** Cooper pairing is mediated by electron-phonon interactions in most of simple metals and alloys which are widely called conventional *** are a few classes of superconductors,however,in which the electron pairing

关键词：电子配对超导体电子-声子相互作用准一维机制铬基 Cooper 量子现象

Adsorption behavior and mechanism of copper ions in the sulfidization flotation of malachite

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International Journal of Mining Science and Technology 2022年第4期32卷 897-906页

作者： han Wang Shuming Wen guang han Yongxin He Qicheng Feng State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Faculty of Land Resource EngineeringKunming University of Science and TechnologyKunming 650093China State Key Laboratory of Mineral Processing Beijing 100160China Yunnan Key Laboratory of Green Separation and Enrichment of Strategic Mineral Resources Kunming University of Science and TechnologyKunming 650093China Inter Mongolia Xingye Mining Company Limited Chifeng 024028China

Malachite is one of the main minerals used for the industrial enrichment and recovery of copper oxide resources, and copper ions are unavoidable metal ions in the flotation pulp. The microflotation, contact angle, and adsorption experiments indicated that pretreatment with an appropriate concentration of copper ions could improve the malachite recovery, and the addition of excess copper ions reduced the hydrophobicity of the malachite surface. The results of zeta potential tests indicated that sodium sulfide and butyl xanthate were also adsorbed on the surface of malachite pretreated with copper ions. X-ray photoelectron spectroscopy(XPS) results indicated that —Cu—O and —Cu—OH bonds were formed on the surface of the samples. After pretreatment with an appropriate concentration of copper ions, the number of —OH groups on the mineral surface decreased, whereas the number of Cu—S groups on the mineral surface increased, which was conducive to the sulfidization of malachite. After adding a high concentration of copper ions, the —OH groups on the mineral surface increased, whereas the number of Cu—S groups decreased, which had an adverse effect on the sulfidization flotation of malachite. Time-of-flight secondary ion mass spectrometry showed that pretreatment with copper ions resulted in a thicker sulfidization layer on the mineral surface.

关键词： Malachite Sulfidization flotation Copper ions Adsorption

New high-T_c iron-selenide superconductor with hydroxide spacer layers

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Science China Materials 2015年第1期58卷 1-2页

作者： guang-han Cao Department of Physics Zhejiang University

Iron-based superconductors include pnictides and *** far,the chalcogenides are much fewer in number[1],thus it is particularly valuable to find new superconductors in iron chalcogenides,for the'ultimate'understanding of iron-based *** tetragonal binary iron selenide(β-Fe1+δSe)is the structurally simplest iron-based superconductor with a superconducting critical temperature(Tc)of 8.5 K at ambient pressure[2].By intercalation of alkali metal ions into

关键词： high New high-T_c iron-selenide superconductor with hydroxide spacer layers Chen

Phase Retrieval of Real-valued Functions in Sobolev Space

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Acta Mathematica Sinica,English Series 2018年第12期34卷 1778-1794页

作者： You Fa LI De guang han College of Mathematics and Information Science Guangxi University Nanning 530004 P. R. China Department of Mathematics University of Central Florida Orlando FL 32816

The Sobolev space HS（Rd） with s 〉 d/2 contains many important functions such as the bandlimited or rational ones. In this paper we propose a sequence of measurement functions { φj^r,k}∈C H^-S（R^d） to the phase retrieval problem for the real-valued functions in H^s（R^d）. We prove that any real-valued function f ∈ H^s （Rd） can be determined, up to a global sign, by the phaseless measurements {｜（ f, φj^r,k}｜}. It is known that phase retrieval is unstable in infinite dimensional spaces with respect to perturbations of the measurement functions. We examine a special type of perturbations that ensures the stability for the phase-retrieval problem for all the real-valued functions in Hs（Rd） ∩ C1（Rd）, and prove that our iterated reconstruction procedure guarantees uniform convergence for any function f ∈ Hs （Rd）∩ C1 （Rd） whose Fourier transform f is L1-integrable. Moreover, numerical simulations are conducted to test the efficiency of the reconstruction algorithm.

关键词： Sobolev space phase retrieval measurement function perturbation retrievable stability,reconstruction stability.

Use of Dispersion Relations in ππ and KK^- Coupled-Channel System

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Communications in Theoretical Physics 2007年第4X期48卷 685-694页

作者： XIAO Zhi-guang ZHENG han-Qing Department of Physics Peking University Beijing 100871 China

Systematic and careful studies are made on the properties of the IJ =00 7rTr and KK^- coupled-channel system, using newly derived dispersion relations between the phase shifts and poles and cuts. The effects of nearby... 详细信息

关键词： ππ scattering

Systems biomedical analysis of Schistosoma japonicum

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Frontiers of Medicine 2010年第2期4卷 157-165页

作者： Ze-guang han Shanghai-MOST Key Laboratory for Disease and Health Genomics Chinese National Human Genome Center at ShanghaiShanghai 201203China Rui-Jin Hospital Shanghai Jiao Tong University School of MedicineShanghai 200025China

Human schistosomiasis,caused mainly by three principal species including Schistosoma japonicum,***,and ***,remains a major public health concern *** is prevalent in southern China,being a major disease risk for 66 million *** bloodﬂuke has a complex life cycle for survival:as a free-living form in fresh water and as a parasite in the snail intermediate and vertebrate deﬁnitive ***-based biomedical analyses,including genomic,transcriptomic,proteomic and metabonomic approaches,have been performed on the *** comprehensive investigations have not only char-acterized the genomic features but also chartered gene and protein expression proﬁles across genders and develop-mental *** integration of the huge information will lay a global and solid foundation for the molecular architecture of the biology,pathogenesis,and host-parasite interactions of the human bloodﬂuke,which will facilitate the development of a new antischistosomal vaccine and drugs as well as diagnostic markers for the treatment and control of schistosomiasis.

关键词： Schistosoma japonicum systems biomedical analysis

Flotation of copper oxide minerals:A review

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International Journal of Mining Science and Technology 2022年第6期32卷 1351-1364页

作者： Qicheng Feng Wenhang Yang Shuming Wen han Wang Wenjuan Zhao guang han State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Faculty of Land Resource EngineeringKunming University of Science and TechnologyKunming 650093China Yunnan Key Laboratory of Green Separation and Enrichment of Strategic Mineral Resources Kunming University of Science and TechnologyKunming 650093China

Copper oxide minerals are important copper resources,which include malachite,azurite,chrysocolla,cuprite,*** is the most widely used method for the enrichment of copper oxide minerals in the mineral processing *** this paper,the surface properties of copper oxide minerals and their effects on the mineral flotation behavior are systematically *** flotation methods of copper oxide minerals and the interaction mechanism with reagents are reviewed in *** methods include direct flotation(using chelating reagents or a fatty acid as collector),sulfidization flotation(using xanthate as collector),and activation flotation(using chelating reagents,ammonium/amine salts,metal ions,and oxidant for activation).An effective way to realize efficient flotation of copper oxide minerals is to increase active sites on the surface of copper oxide minerals to enhance the interaction of collector with the mineral ***,various perspectives for further investigation on the efficient recovery of copper oxide minerals are proposed.

关键词： Copper oxide minerals Direct flotation Sulfidization flotation Activation flotation

Superconductivity with peculiar upper critical fields in quasi-one-dimensional Cr-based pnictides

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Chinese Physics B 2018年第10期27卷 15-26页

作者： guang-han Cao Zeng-Wei Zhu Department of Physics Zhejiang University Hangzhou 310027 China Wuhan National High Magnetic Field Center School of Physics Huazhong University of Science and Technology Wuhan 430074 China

The discovery of superconductivity in quasi-one-dimensional Cr-based pnictides A2Cr3As3（A = alkali metals） has generated considerable research interest, primarily owing to their reduced dimensionality, significant electron correlations,and possible unconventional superconductivity. The upper critical field（Hc2） provides important information on the superconducting pairing. In this paper, we first briefly overview the latest research progress on the Cr-based ***, we introduce typical Hc2（T） behaviors of type-II superconductors in relation with the pair-breaking *** a description of the measurement method for Hc2, we focus on the analysis of Hc2 data, especially for the temperature and angle dependence, in K2Cr3As3 crystals. The result indicates（i） an absence of Pauli-paramagnetic pair breaking for field perpendicular to the Cr3As3 chains, and（ii） a unique threefold modulation for the in-plane Hc2Φ profile. Finally we conclude with remarks on the possible unconventional superconducting pairing symmetry.

关键词： Cr-based superconductors upper critical fields unconventional superconductivity