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Pre-reduction of WO_(3)-Co_(3)O_(4)by H_(2)-C_(2)H_4 in a fluidized bed

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Chinese Journal of Chemical Engineering 2024年第2期66卷 273-284页

作者： Huijun Shang Hengli li Weijun li feng pan Zhan Du State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of Sciences(CAS)Beijing 100190China College of Chemical Engineering Nanjing Technology UniversityNanjing 211816China School of Chemistry and Chemical Engineering Shihezi UniversityShihezi 832003China College of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Chinalco Environmental Protection and Energy Conservation Group Co. Ltd.Xiong’an 071700China

In order to avoid the formation ofηphase(W_(6)Co_(6)C or W_(3)Co_(3)C)that adversely affects the sintering process and its products in the preparation process of ultra-fine WC-Co powder,a technical route of prereduction of WO_(3)-Co_(3)O_(4)to WO_(2)-Co and then deep reduction carbonization to WC-Co powder has been *** study mainly investigates the influence of gas partial pressure on the pre-reduction process of WO_(3)-Co_(3)O_(4)under a mixed atmosphere of H_(2)-C_(2)H_(4)-Ar at 600℃and establishes the kinetic equations of pre-reduction and carbon *** results indicate that increasing the partial pressure of hydrogen is conducive to the rapid and complete conversion of WO_(3) to WO_(2).High carbon content can be generated by the deposition of C_(2)H_(4),and it hinders the diffusion of the reducing gas;WO_(3)still cannot be completely reduced to WO_(2)as the partial pressure of C_(2)H_(4) increases to 60%.For the carbon evolution of C_(2)H_(4),the carbon amount is positively related to the H_(2)partial pressure,but it shows the highest amount and evolution rate when the ethylene partial pressure is 20%.Based on the reduction rate curves of WO_(3) and carbon evolution rate curves of C_(2)H_(4),the rate equations of pre-reduction and carbon evolution of WO_(3)-Co_(3)O_(4)system at 600℃are *** pre-reduction reaction belongs to the first-order reaction,and its equation is expressed as follows:r=-(dw_(WO_(3)))/dt=(9±0.15)×10^(-2)×P_(H_(2))^(0.44)P_(C_(2)H_(4))&(0.57)The carbon deposition rate equation of C_(2)H_(4) can be expressed as follows:r=-(dc_C)/dt=r_f-r_b≌7.35×10^(-2)×P_(C_(2)H_(4))^(0.31)

关键词： Fluidization WO_(3)-Co_(3)O_(4) Reduction Carbon deposition Rate equation

Crystallization of RE_(2)(OH)_(2)CO_(3)SO_(4)·nH_(2)O as a new family of layered hydroxides(RE=Gd-Lu lanthanides and Y),derivation of RE_(2)O_(2)SO_(4),photoluminescence and optical thermometry

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Journal of Rare Earths 2024年第8期42卷 1496-1506,I0003页

作者： Fan li Zhenqi Song Zhiyuan pan Sihan feng Qi Zhu Ji-Guang li Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China Research Center for Functional Materials National Institute for Materials ScienceTSsukuboaIbaraki3050044Japan

Layered rare-earth hydroxides(LREHs) draw wide research interest because of their peculiar crystal structure,rich interlayer chemistry and abundant functionality of the RE element,but are limited to the two categories of RE_(2)(OH)_(5)A·nH_(2)O(A:typical of Cl^(-)or NO_(3)^(-)) and RE_(2)(OH)_(4)SO_(4)·nH_(2)*** the other hand,rare-earth oxysulfates(RE_(2)O_(2)SO_(4)) have attracted attention due to their properties of large-capacity oxygen storage,low-temperature magnetism and luminescence,but their preparation procedure mostly involves toxic SO_(x) gases and/or complicated *** this work,RE_(2)(OH)_(2)CO_(3)SO_(4)·nH_(2)O as a new family of LREHs(RE=Gd-Lu lanthanides and Y) were produced via hydrothermal reaction,from which phase-pure RE_(2)O_(2)SO_(4) was derived via subsequent annealing at 800℃ in air without the involvement of SO_(x),The compounds were thoroughly characterized to reveal the intrinsic influence of lanthanide contraction(RE^(3+) radius) on crystal structure,thermal behavior(dehydroxylation/decarbonation/desulfurization),vibrational property and crystallite *** analyzing the photoluminescence of Eu^(3+) and Sm^(3+)in the Gd_(2)O_(2)SO_(4) typical host it is found that the 617 nm(Eu^(3+),λ_(ex)=275 nm) and 608 nm(Sm^(3+),λ_(ex)=407 nm) main emissions can retain as high as ^(7)9.6% and 85.5%of their room-temperature intensities at 423 K,with activation energies of ~0.19 and 0.21 eV for thermal quenching,*** also indicates that both the phosphors have the potential for optical temperature sensing via the fluorescence intensity ratio(FIR) technology,whose maximum relative sensitivity reaches -2.70%/K for Eu^(3+)and 1.73%/K for Sm^(3+) at 298 K.

关键词： Layered hydroxide RE_(2)O_(2)SO_(4) Luminescence Optical temperature sensing Rare earths

Occurrence and vertical distribution of aluminum and rare earths in weathered crust elution-deposited rare earth ore:Effect of soil solution pH and clay minerals

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Journal of Rare Earths 2024年第7期42卷 1394-1402,I0007页

作者： Jiaxin pan Longsheng Zhao Zheng li Xiaowei Huang Zongyu feng Jun Chen National Engineering Research Center for Rare Earth China GRINM Group Co.Ltd.Beijing100088China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing100083China GRIREM Hi–Tech Co. Ltd.Langfang065201China GRIREM Advanced Materials Co. Ltd.Beijing100088China GRIMAT Engineering Institute Co. Ltd.Beijing101407China

Weathered crust elution-deposited rare earth ore is crucial source of medium and heavy rare earths,with in-situ leaching being the most common mining *** high contents of impurity of aluminum in the leach solution are a significant challenge for the subsequent enrichment process of rare earths.A comprehensive understanding of the occurrences and vertical distribution of aluminum and rare earths within typical vertical profiles can provide valuable insights into entire design of the in-situ *** paper improves a five-step sequential extraction method to analyze the occurrence and vertical distribution of rare earths and aluminum in vertical profiles from Chongzuo and *** results demonstrate that soil solution pH is the main factor affecting the vertical distribution of ionexchangeable rare *** samples have distinct areas of enrichment for ion-exchangeable rare earths or ***-exchangeable rare earths are primary concentrated in the middle and lower parts of the ore layer(4-13 m in Chongzuo,14-22 m in Longyan),while the ion-exchangeable aluminum is mainly enriched in the upper part of the ore layer(1-5 m in Chongzuo,and 2-14 m in Longyan).The vertical distribution of inorganic hydroxy aluminum is likely influenced by the micromorphology and particle size of the clay *** inorganic hydroxy aluminum concentration in Chongzuo samples decreases continuously from 415.65 to 120.95 mg/kg with increasing sampling depth,whereas the concentration in Longyan samples(110.55-171.27 mg/kg)is almost independence with sampling *** results provide direct guidance for the entire design of the injection well depth and the leaching parameters,thereby inhibiting the leaching of impurity of aluminum and lower the consumption of leaching agent.

关键词： Weathered crust elution-deposited rare earth ore Sequential extraction Occurrence Aluminum Rare earth elements

Image-based Virtual Exhibit and Its Extension to 3D

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International Journal of Automation and computing 2007年第1期4卷 18-24页

作者： Ming-Min Zhang Zhi-Geng pan li-feng Ren Peng Wang State Key Laboratory of CAD＆CG Zhejiang University Hangzhou 310027 PRC

In this paper we introduce an image-based virtual exhibition system especially for clothing product. It can provide a powerful material substitution function, which is very useful for customization clothing-built. A novel color substitution algorithm and two texture morphing methods are designed to ensure realistic substitution result. To extend it to 3D, we need to do the model reconstruction based on photos. Thus we present an improved method for modeling human body. It deforms a generic model with shape details extracted from pictures to generate a new model. Our method begins with model image generation followed by silhouette extraction and segmentation. Then it builds a mapping between pixels inside every pair of silhouette segments in the model image and in the picture. Our mapping algorithm is based on a slice space representation that conforms to the natural features of human body.

关键词： Virtual exhibition color substitution texture morphing reflection component decomposition virtual reality.

Regioselective and asymmetric allylic alkylation of vinyl epoxides for the construction of allylic alcohols via synergistic catalysis

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Science China Chemistry 2024年第2期67卷 542-550页

作者： Min Chen Longqing Yang Yuzhen li Yinhe Qu Guihua pan Xiaoming feng Xiaohua liu Key Laboratory of Green Chemistry&Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu610064China

A highly efficient asymmetric allylic alkylation of cyclic and acyclic carbon nucleophiles with vinyl epoxides has been developed,which exhibits good functional group compatibility,high atomic and step *** protocol utilizes a strategy of synergistic catalysis with a chiral N,N'-dioxide/Ni~Ⅱ complex and an achiral Pd~0 catalyst,generating a series of multisubstituted allylic alcohols with a quaternary carbon stereocenter in high yield and excellent regio-,Z/E-and enantioselectivity under mild *** transformations of the product demonstrate the potential utility of this protocol in the synthesis of allyl alcohol derivatives and natural product *** studies revealed that the N,N′-dioxide/metal complexes play an important role in controlling the Z/E-and *** density functional theory(DFT) calculations further demonstrated that multiple C–H···π interactions between the aromatic rings of the two substrates and the amide moiety in the ligand stabilized the dominant transition state.

关键词： asymmetric allylic alkylation synergistic catalysis vinyl epoxides allyl alcohol multiple weak interactions

Unconventional Fluorescent and Multi-responsive Polyethyleneimine with LCST and UCST Behavior:Synthesis,Characterization and Biological Applications

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Chinese Journal of Polymer Science 2024年第6期42卷 826-837页

作者： feng-Ming Yin li-li Wu Shu-Sheng li Xiao-Na pan Xiao-li Zhu Xu-Bao Jiang Xiang Zheng Kong College of Chemistry and Chemical Engineering University of JinanJinan250022China Shandong Institute for Product Quality Inspection Jinan250102China College of Chemical Engineering Tianjin UniversityTianjin300072China

Non-aromatic fluorescent and multi-responsive materials,exhibiting inherent fluorescence emission and controlled phase change,have garnered significant attention in recent ***,the underlying interaction between their fluorescent properties and phase transition remains *** this study,we synthesized a series of catalyst-free aza-Michael addition-based polyethyleneimine(RFPEI)materials by reacting polyethyleneimine(PEI)with N-isopropyl acrylamide(NIPAM).The resulting RFPEI was comprehensively characterized,and demonstrated dual-phase transition behavior(LCST and UCST)in water,which could be finely tuned by adjusting its composition or external factors such as ***,upon UV irradiation(365 nm),RFPEI exhibited strong fluorescence *** further investigated the effects of NIPAM grafting percentage to PEI,polymer concentration,and pH on the LCST/UCST and fluorescent properties of RFPEI aqueous ***,we showcased the great potential of RFPEI as a versatile tool for physiological cell imaging,trace detection,and controlled release of *** study presents a novel class of stimuli-responsive fluorescent materials with promising applications in the field of biomedicine.

关键词： Polyethyleneimine Multi-responsiveness Intrinsic fluorescence emission Cell imaging Controlled drug release

Mechanism of local solidification time variations with melt rate during vacuum arc remelting process of 8Cr4Mo4V high-strength steel

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Journal of Iron and Steel Research International 2024年第2期31卷 377-388页

作者： Tao pan Hong-chun Zhu Zhou-hua Jiang Hua-bing li Rui Zhang Hao feng School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina

A 2D axisymmetric numerical model was established to investigate the variations of molten pool with different melt rates during the vacuum arc remelting of 8Cr4Mo4V high-strength steel,and the ingot growth was simulated by dynamic mesh *** results show that as the ingot grows,the molten pool profile changes from shallow and flat to V-shaped,and both the molten pool depth and the mushy width ***,the variation of both the molten pool shape and the mushy width melt rate is clarified by the thermal equilibrium *** melt rate increases,both the molten pool depth and the mushy width *** is caused by the increment in sensible heat stored in the ingot due to the limitation of the cooling capacity of the *** nonlinear increment in sensible heat leads to a nonlinear increase in the mushy *** addition,as melt rate increases,the local solidification time(LST)of ingot decreases obviously at first and then *** melt rate is controlled in a suitable range,LST is the lowest and the secondary dendrite arm spacing of the ingot is the smallest,which can effectively improve the compactness degree of 8Cr4Mo4V high-strength steel.

关键词： 8Cr4Mo4V high-strength steel Vacuum arc remelting process Melt rate Molten pool Local solidification time

RIOK1 synergizes with TRIP13 by regulating the E2F-Rb signaling pathway to promote the proliferation of esophageal cancer cells

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Genes & Diseases 2024年第3期11卷 55-58页

作者： Chengyu li Deyuan pan Wan lin Danxia Deng Yingxin Zhou Hui Zhao feng pan liyan Xu Enmin li lin Long The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area Department of Biochemistry and Molecular BiologyShantou University Medical CollegeShantouGuangdong 515041China Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology Institute of Oncologic PathologyShantou University Medical CollegeShantouGuangdong 515041China Institute of Basic Medical Science Cancer Research CenterShantou University Medical CollegeShantouGuangdong 515041China Clinical Research Center Shantou Central HospitalShantouGuangdong 515041China

Esophageal cancer is one of the leading causes of cancer death in the world,with approximately half of the new cases occurring in China every year.^(1)Esophageal squamous cell carcinoma(ESCC)is the main subtype,accounting for more than 90%,and the five-year survival rate is less than 10%.Using large-scale genome analysis,many driver mutations and key pathways associated with ESCC have been ***,these genomic signatures have not improved the clinical management of EscC patients,or established effective targeted therapy.^(2)Esophageal cancer still lacks representative molecular markers.

关键词： cancer esophageal Esophageal

Nitrogen and fluorine co-doped graphene for ultra-stable lithium metal anodes

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Nano Research 2024年第8期17卷 7212-7220页

作者： pan li Yifan liu Xujian Bao Jinghao Xie Zhao li Hongcheng li Qiang Ren Xiaomiao feng Yue Hu Yanwen Ma State Key Laboratory for Organic Electronics and Information Displays(KLOEID)and Jiangsu Key Laboratory for Biosensors Institute of Advanced Materials(IAM)Nanjing University of Posts and TelecommunicationsNanjing 210023China Key Laboratory of Carbon Materials of Zhejiang Province College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325000China

The heteroatom doping strategies have been utilized to effectively improve the performance of the carbon-based hosts,such as graphene,for lithium(li)metal in high energy density lithium metal ***,solely doped graphene hosts often need the assistance of other materials with either better lithiophilicity or electronic conductance to achieve smooth and efficient deposition of li,which adds extra weight or ***,graphene co-doped by nitrogen and fluorine(NFG)is employed as a stable host for li,where the N-doping provides lithiophilicity and electronic conductivity lacked by F-doping and the F-doping facilitates fast formation of solid electrolyte interphase(SEI)retarded by *** well regulation of li plating/stripping and SEI formation is verified by quickly stabilized and small-magnitude voltage hysteresis,which stands out in li hosts based on doped graphene and leads to excellent long-term cycling performance of NFG based electrodes.A voltage hysteresis of 20 mV is observed for more than 850 h in the symmetrical *** remarkable efficiency of lithium usage is confirmed by the highcapacity retention of a full cell paired with liFePO_(4)(LFP),which exceeds 70%after 500 *** work presents an innovative perspective on the control of li plating/stripping by simultaneously introducing two kinds of dopants into graphene and paving the way for exploring practical li metal batteries.

关键词： Co-doped graphene lithium metal anode dendrite suppression lithiophilic skeleton solid electrolyte interphase(SEI)formation