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On-line determination of selenium compounds in tea infusion by extractive electrospray ionization mass spectrometry combined with a heating reaction device

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Chinese Chemical Letters 2025年第1期36卷 496-500页

作者： Lu Huang Jiang Wang Hong Jiang Lanfang Chen Huanwen Chen Academician Workstation Jiangxi University of Chinese MedicineNanchang 330004China Suzhou Jingcheng Precision instrument Technology co. Ltd.Suzhou 215228China The First Affiliated Hospital of Nanchang University Nanchang 330006China

Selenium is one of the important trace elements in the human *** deficiency will directly affect human *** people's attention to health,the content of selenium in food has gradually attracted ***,detecting selenium compounds in complex samples remains a *** this work,we built an online heating-reaction *** device combines the electrospray extraction ionization mass spectrometry(EESI-MS)with the heating reaction device,which can simultaneously detect various selenium compounds in complex liquid *** acidic conditions,the sample was heated and catalyzed by a heating reaction device,so that the SeO~(2-)_(3)and O-phenylenediamine(OPD)could generate 1,3-dihydro-2,1,*** on the above reactions,we can detect organic selenium,inorganic selenium and other compounds in liquid samples by organic mass *** this experiment,we determined the content of three forms of selenium:selenomethionine(SeMet),l-selenocystine(SeCys(2)),and sodium *** calibration curves for SeMet,SeCys(2),and sodium selenite showed strong linearity within a range of 0.50-50.00μg/*** limits of detection(LOD)for the three compounds were 0.22,0.27,and 0.41μg/L,*** limits of quantification(LOQ)were 0.68,0.81,and 1.23μg/L,*** recoveries at three levels ranged from 98.8%to 106.1%.In addition,this method can simultaneously detect three selenium compounds and three other specific chemical components in tea infusion samples,providing a rapid and efficient method for identifying tea quality.

关键词： Heating reaction device Extractive electrospray ionization mass spectrometry Inorganic selenium Selenium compounds Tea infusion

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Leaching of rare earths and aluminum in weathered crust elutiondeposited rare earth ore using magnesium sulfate:Effect of aluminum content in leaching agent solution

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Journal of Rare Earths 2025年第1期43卷 191-198,I0007页

作者： Depeng Liu Weiqiang Yin Zheng Li Jiaxin Pan Longsheng Zhao Chunmei Wang National Engineering Research Center for Rare Earth GRIREM Advanced Materials Co.Ltd.Beijing100088China GRIREM Hi-Tech co. Ltd.Langfang065201China GRIMAT Engineering Institute co. Ltd.Beijing100088China Rare Earth Functional Materials(Xiong'an)Innovation Center co. Ltd.Xiong'an071700China

Aluminum is the main impurity of the weathered crust elution-deposited rare earth ore(WCED-REO).Efficient leaching of rare earths and low leaching of aluminum are of great importance for the leaching of the *** effects of pH,MgSO_(4) concentration and Al^(3+)concentration of the leaching agent solution on the column leaching behaviors of WCED-REO using magnesium sulfate were *** data show that controlling the MgSO_(4) concentration to 0.15 mol/L,pH of the leaching agent solution to 2,the leaching amount of aluminum from the rare earth ore gradually decreases with the increase of Al^(3+)concentration in the leaching agent solution,indicating that Al^(3+)in the leaching agent solution may act as leaching agent to participate in the ion exchange of RE3+,but the leaching amounts of rare earths change insignificantly as the Al^(3+)concentration is *** the MgSO_(4) concentration is beneficial to the leaching of aluminum,and when the Al^(3+)concentration is 0.04 mol/L(Al accumulation),the amount of Al^(3+)leached from the rare earth ore increased gradually with increasing the MgSO_(4) *** pH of the leaching agent solution has a significant influence on the leaching of aluminum in the rare earth ore,and the leaching amount of aluminum from the rare earth ore increases gradually with decreasing the *** the Al^(3+)conce ntration is 0.04 mol/L(Al accumulation)and the pH of the leaching agent solution is above 2.0,the aluminum in the leaching agent solution can be back-adsorbed onto the rare earth ore,and the amount of the back-adsorbed Al^(3+)increases with increasing the pH of the leaching agent *** injection rate of the leaching agent solution has slight effect on the leaching behavior of rare earths and *** summary,leaching of Al^(3+)and consumption of MgSO_(4) can be reduced by regulating the accumulation of aluminum,MgSO_(4) concentration and pH.

关键词： Weathered crust elution-deposited rare earth ore Rareearths Magnesium sulfate Rare earth leaching Aluminum Back-adsorption

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Design and preparation of a sintered Nd-Y-Fe-B magnet with high magnetic properties via multi-main-phase process and subsequent grain boundary diffusion

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Journal of Rare Earths 2025年第2期43卷 304-311页

作者： Fugang Chen Suxin Lu Jie Wang Yong Zhao Wenqiang Zhao Zhi Xu School of Materials Science and Engineering Jiangsu University of Science and Technology Baotou Tianshi Rare Earth New Materials co. Ltd. Jiangsu Yangzi Xinfu Shipbuilding co. Ltd.

A sintered Nd-Y-Fe-B magnet was designed and manufactured by the multi-main-phase *** distributed Y in the magnet decreases the adverse magnetic weakening effect of Y on the *** boundary diffusion process（GBDP） was conducted to further enhance the coercivity of the Nd-Y-Fe-B *** coercivity increases significantly from 884 to 1741 kA/m after GBDP with *** mechanism of the coercivity enhancement is discussed based on the microstructure *** simulation reveals that when the diffused Tb-rich shell thickness is lower than 12 nm the c-plane shell（perpendicular to the c-axis） is much more effective in enhancing the coercivity than the side plane shell（parallel to the c-axis）.But when the Tb-rich shell thickness is above12 nm the side plane shell contributes more to the coercivity *** results in this work can help to design and manufacture Nd-Fe-B magnets with low cost and high magnetic properties.

关键词： Grain boundary diffusion Micromagnetic simulation Multi-main-phase process Nd-Fe-B magnets Rare earths

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MOF-derived Ni3Fe/Ni/NiFe2O4@C for enhanced hydrogen storage performance of MgH2

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Journal of Energy Chemistry 2025年第2期101卷 333-344页

作者： Yangping Chen Bolin Sun Guoqing Zhang Siyuan Ni Canbing Li Juxiong Tian Yanrui Zhang Xinxi Li School of Materials and Energy Guangdong University of Technology Shen Zhen Source Sensor Technology co. Ltd Department of Electrical Engineering Shanghai Jiao Tong University China Power Investment Xinjiang Energy & Chemical Group Hotan co.ltd

Magnesium hydride（MgH2） is an important material for hydrogen（H2） storage and transportation owing to its high capacity and ***,its intrinsic properties have considerably limited its industrial *** this study,the NiFe-800 catalyst as metal-organic framework（MOF） derivative was first utilized to promote the intrinsic properties of *** to pure MgH2,which releases1.24 wt% H2in 60 min at 275℃,the MgH2-10 NiFe-800 composite releases 5.85 wt% H2in the same *** at a lower temperature of 250℃,the MgH2-10 NiFe-800 composite releases 3.57 wt% H2,surpassing the performance of pure MgH2at 275℃.correspondingly,while pure MgH2absorbs 2.08 wt% H2in60 min at 125℃,the MgH2-10 NiFe-800 composite absorbs 5.35 wt% H2in just 1 min,Remarkably,the MgH2-10 NiFe-800 composite absorbs 2.27 wt% H2in 60 min at 50℃ and 4.64 wt% H2at 75℃.This indicates that MgH2-10 NiFe-800 exhibits optimum performance with excellent kinetics at low ***,the capacity of the MgH2-10 NiFe-800 composite remains largely stable after ***,the Mg2Ni/Mg2NiH4acts as a "hydrogen pump",providing effective diffusion channels that enhance the kinetic process of the composite during ***,Fe0facilitates electron transfer and creates hydrogen diffusion channels and catalytic ***,carbon（C） effectively prevents particle agglomeration and maintains the cyclic stability of the ***,the synergistic effects of Mg2Ni/Mg2NiH4,Fe0,and C considerably improve the kinetic properties and cycling stability of *** work offers an effective and valuable approach to improving the hydrogen storage efficiency in the commercial application of MgH2.

关键词： Catalysts Hydrogen energy MgH2 MOF derivative Solid state storage

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Evaluation of the shear stability of aerobic granular sludge from a pilot-scale membrane bioreactor:Establishment of a quantitative method

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Journal of Environmental Sciences 2025年第2期148卷 579-590页

作者： Biao Yang Bingduo Wang Liying Bin Weirui Chen Xinyi Chen Ping Li Shanglong Wen Shaosong Huang Zhiqi Zhang Bing Tang School of Environmental Science and Engineering Guangdong University of TechnologyGuangzhou 510006China Guangdong Guangshen Environmental Protection Technology co. Ltd.Guangzhou 510663China Guangdong Yuehai Water Investment co. Ltd.Shenzhen 518000China

This work established a quantitative method to access the shear stability of aerobic granular sludge(AGS)and validated its feasibility by using the mature AGS from a pilot-scale(50 tons/day)membrane bioreactor(MBR)for treating real municipal *** results showed that the changing rate( S)of the peak area(S)of granule size distribution(GSD)exhibited an exponential relationship(R^(2)≥0.76)with the shear time(y=a−b·cx),which was a suitable indicative index to reflect the shear stability of different AGS *** limiting granule size(LGS)was defined and proposed to characterize the equilibrium size for AGS after being sheared for a period of time,whose value in terms of Dv50 showed high correlation(R^(2)=0.92)with the parameter *** free Ca^(2+)(28.44-34.21 mg/L)in the influent specifically interacted with polysaccharides(PS)in the granule’s extracellular polymeric substance(EPS)as a nucleation site,thereby inducing the formation of Ca precipitation to enhance its Young’s modulus,while Ca2+primarily interacted with PS in soluble metabolic product(SMP)during the initial granulation ***,the Young’s modulus significantly affected the parameter a related to shear stability(R^(2)=0.99).Since the parameter a was more closely related(R^(2)=1.00)to S than that of the parameter b or c,the excellent correlation(R^(2)=0.99)between the parameter a and the wet density further verified the feasibility of this method.

关键词： Shear stability Quantitative evaluation Aerobic granular sludge Membrane bioreactor Pilot-scale study Municipal wastewater

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Super-high bed sintering for iron ores:variation and optimization of bed resistance

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Journal of Iron and Steel Research International 2025年第1期32卷 40-51页

作者： Liang-ping Xu Lin Xiong Hui-bo Liu Xi-duan Yang Ai-xiang Mao Pei-dun Chen Guang-hui Li School of Minerals Processing and Bioengineering Central South UniversityChangsha410083HunanChina Central Research Institute Baosteel Group Co.Ltd.Shanghai201900China Manufacturing Management Department Guangdong Zhongnan Iron and Steel Co.Ltd.Shaoguan512123GuangdongChina Technology and Development Center Shandong Taishan Iron and Steel Group Co.Ltd.Jinan271100ShandongChina

As the bed depth increases,sintering yield increases,but the productivity *** reveal the reasons for the decrease in productivity and explore targeted solutions,the bed resistance of mixtures,wet zone,and combustion zone was analyzed in the *** results showed that the decreased porosity of mixture resulted in the increased bed resistance by 160.56%when the bed depth increased from 600 to 1000 *** improving porosity of 1%by adding loosening bars with optimized size and distribution,the bed resistance decreased,and the productivity increased by 5%.The increase in bed depth increased the thickness of the wet zone from 120 to 680 mm and the resistance from 1.56 to 8.83 *** using a three-stage intensive mixer and pre-adding water for granulation,the moisture of mixture was reduced by 0.6%,and the sintering productivity increased by 4%.Besides,the high bed resistance is mainly caused by the increase in the thickness of the combustion zone from 31.9 to 132.7 mm,and the bed resistance increased from 0.70 to 5.62 *** bed resistance of the combustion zone at 900 mm was increased by 90.51%compared to 700 *** optimization of the distribution of coke breeze,the thickness of combustion zone at the lower layer decreased from 132.7 to 106.84 mm and permeability improved significantly.

关键词： Super-high bed sintering Bed resistance Permeability Productivity Wet zone combustion zone

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Flow behavior and dynamic softening mechanism of Pt−10Ir precious alloy

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Transactions of Nonferrous Metals Society of China 2025年第1期35卷 225-242页

作者： Xin-pei ZHANG Jun-jie HE Lin PI Quan FU Wen-yan ZHOU Jun CHENG Sheng-wen BAI Xuan ZHOU Yi LIU Yong MAO Materials Genome Institute School of Materials and EnergyYunnan UniversityKunming 650091China Kunming Precious Materials&Technology co. Ltd.Yunnan Precious Metals Laboratory Co.Ltd.Sino-Platinum Metals Co.Ltd.Kunming 650106China Kunming Institute of Precious Metals Kunming 650106China State Key Laboratory of Advanced Technologies for comprehensive Utilization of Platinum Metals Sino-Platinum Metals Co.Ltd.Kunming 650106China Shaanxi Key Laboratory of Biomedical Metal Materials Northwest Institute for Non-ferrous Metal ResearchXi’an 710016China college of Materials Science and Engineering Chongqing UniversityChongqing 400044China

The hot deformation behavior of Pt−10Ir alloy was studied under a wide range of deformation *** a low deformation temperature(950−1150℃),the softening mechanism is primarily dynamic *** addition,dynamic recrystallization by progressive lattice rotation near grain boundaries(DRX by LRGBs)and microshear bands assisted dynamic recrystallization(MSBs assisted DRX)coordinate the ***,it is difficult for the dynamic softening to offset the stain hardening due to a limited amount of DRXed *** a high deformation temperature(1250−1350℃),three main DRX mechanisms associated with strain rates occur:DRX by LRGBs,DRX by a homogeneous increase in misorientation(HIM)and geometric DRX(GDRX).With increasing strain,DRX by LRGBs is enhanced gradually under high strain rates;the“pinch-off”effect is enhanced at low strain rates,which was conducive to the formation of a uniform and fine microstructure.

关键词： platinum alloy hot deformation microstructure evolution dynamic recovery dynamic recrystallization

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Prioritization Hindsight Experience Based on Spatial Position Attention for Robots

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Machine Intelligence Research 2025年第1期22卷 160-175页

作者： Ye Yuan Yu Sha Feixiang Sun Haofan Lu Shuiping Gou Jie Luo China Nuclear Power Technology Research Institute co. Ltd.Shenzhen518028China School of Artificial Intelligence Xidian UniversityXi’an710071China Suzhou Tianhe China Power International Engineering Technology co. Ltd.Suzhou215000China

Sparse rewards pose significant challenges in deep reinforcement learning as agents struggle to learn from experiences with limited reward *** experience replay(HER)addresses this problem by creating“small goals”within a hierarchical decision ***,HER does not consider the value of different episodes for agent *** this paper,we propose SPAHER,a framework for prioritizing hindsight experiences based on spatial position *** allows the agent to prioritize more valuable experiences in a manipulation *** achieves this by calculating transition and trajectory spatial position functions to determine the value of each episode for experience *** evaluate SPAHER on eight robot manipulation tasks in the Fetch and Hand environments provided by OpenAI *** results show that our method improves the final mean success rate by an average of 3.63%compared to HER,especially in challenging Hand ***,these improvements are achieved without any increase in computation time.

关键词： Hindsight experience replay spatial position attention sparse reward deep reinforcement learning prioritization hindsight experience

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Isothermal reduction kinetics and reduction prediction for iron ore pellets

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Journal of Iron and Steel Research International 2025年第1期32卷 64-72页

作者： Fei Meng Hao Liu Yue-lin Qin Huang-jie Hua Yin Deng Ze-zheng Sun Long-hai Liu School of Metallurgy and Materials Engineering Chongqing University of Science and TechnologyChongqing401331China CISDI Group co. Ltd.Chongqing401122China college of Materials Science and Engineering Chongqing UniversityChongqing400044China Sichuan Desheng Group Vanadium&Titanium co. Ltd.Leshan614000SichuanChina

Iron ore pellets,as one of the main charges of blast furnaces,have a greater impact on the co_(2)emission reduction and stable operation of blast *** isothermal reduction behavior of the pellets obtained from a Chinese steel plant was studied in the gas mixtures of co and N_(2).The results showed the reduction process is divided into two *** reduction in the initial stage(time t≤40 min)is cooperatively controlled by internal diffusion and interface chemical reactions with the activation energy of 30.19 and 16.67 kJ/mol,*** controlling step of the reduction in the final stage(t>40 min)is internal diffusion with the activation energy of 34.60 kJ/*** reduction process can be described by two equations obtained from kinetic *** reduction degree can be predicted under different temperatures and time,and the predicted results showed an excellent correlation with the experimental *** reduction mechanisms were confirmed by the analysis of the scanning electron microscope equipped with an energy dispersive spectrometer and optical microscope.

关键词： Pellet Reduction behavior Kinetics Mechanism Reduction prediction

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construction Monitoring and Analysis of Asymmetric Prestressed concrete Bridge Crossing Multiple-Line Railways

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Structural Durability & Health Monitoring 2025年第2期19卷 385-398页

作者： Yi Wang Bing Wang Changwen Li Feng Zheng Yong Liu Shaohua He Guangzhou Railway Investment construction Group co. Ltd.Guangzhou510000China China Railway Third Bureau Group co. LtdTaiyuan030024China School of Civil and Transportation Engineering Guangdong University of TechnologyGuangzhou510006China

complex bridge structures designed and constructed by humans often necessitate extensive on-site execution,which carries inherent ***,a variety of engineering practices are employed to monitor bridge *** paper presents a case study of a large-span prestressed concrete(PC)variable-section continuous girder bridge in China,proposing a feedback system for construction monitoring and establishing a finite element(FE)analysis model for the entire *** alignment of the completed bridge adheres to the initial design expectations,with maximum displacement and pre-arch differences from the ideal state measuring 6.39 and 17.7 mm,respectively,which were less than the 20 mm limit required by the ***,the stress monitoring showed that the maximum compressive stress was 10.44 MPa,which was 7.5%different from the finite element results,and better predicted the most unfavorable possible *** results demonstrate that a scientifically rigorous construction monitoring and feedback system can ensure the safety of bridge construction and meet the expected construction *** findings presented in this paper provide valuable insights for bridge construction monitoring practices.

关键词： continuous girder bridge construction monitoring bridge alignment stress monitoring

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