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Preparation and Superconducting Properties of F-doped SmO_(1-x)F_xFeAs

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Journal of materials Science & Technology 2011年第3期27卷 227-232页

作者： Zhiyong liu Hongli Suo lin ma Min liu Zhiping Wu Zhichao Guo Luping Han Meiling Zhou Key Laboratory of Advanced Functional materials Ministry of Education College of Materials Science and Engineering Beijing University of Technology Beijing 100022 China

Here we report the fabrication and superconductivity of the iron-based arsenic oxide SmO1-xFxFeAs compound. X-ray diffraction （XRD） results prove that the lattice parameters a and c decrease systematically with increasing x in between 0〈x≤0.35, but when x〉0.35 the a and c increase with the decrease of x in the SmO1-xFxFeAs. The critical temperature （To） increases with increasing x in between 0.15≤x≤0.3, while x〉0.3 the Tc decreases with the increase ofx. It is found that at x=0.3 SmO0.7F0.3FeAs has the highest onset resistivity transition temperature of 55.5 K. The critical current density （Jc） value at 10 K for the obtained ***0.3FeAs is 1.3×10^5 A/cm^2 （0 T）. Meanwhile one can estimates Hc2（0） from the slope of the Hc2（T） curve at T=-Tc （Hc2 is the upper critical field）, and for the 90% normal-state resistivity （Pn） criterion （Tc=55 K）, Hc2（0） is determined to be -253 T.

关键词： SmO1-xFxFeAs compound F-doped Superconductivity

Research on manufacture technology of spherical fuel elements by dry-bag isostatic pressing

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Nuclear Science and Techniques 2022年第10期33卷 79-89页

作者： Zhen-Ming Lu Wen-Ke Zhang Jie Zhang Xiang-Wen Zhou Kai-Hong Zhang ma-lin liu Xuan-Ke Li Bing liu Hubei Province Key Laboratory of Coal Conversion and New Carbon materials Wuhan University of Science and TechnologyWuhan 430081China Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyTsinghua UniversityBeijing 100084China

The steady development of high-temperature gas-cooled reactors(HTRs) has increased the requirements for the production cost and quality of fuel elements. Green fuel element pressing is one of the key steps to increase the production capacity. This paper proposes a proprietary vacuum dry-bag isostatic pressing(DIP) apparatus. The structural change of the matrix graphite powder during the DIP process was examined by analyzing the density change of the matrix graphite spheres with pressure. The soft molding process was simulated using the finite element method. The dimensional changes in the spheres during the pressing, carbonization, and purification stages were explored. The performance of the fuel matrix produced by the DIP method was comprehensively examined. The fuel matrix met the technical requirements and its anisotropy was significantly reduced. The DIP method can significantly improve both the production efficiency and quality of fuel elements. This will play a key role in meeting the huge demand for fuel elements of HTRs and molten salt reactors.

关键词： Dry-bag isostatic pressing High-temperature gas-cooled reactor(HTR) Spherical fuel element Finite element simulation Soft molding

High-Superelasticity NiTi Shape Memory Alloy by Directed Energy Deposition-Arc and Solution Heat Treatment

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 132-144页

作者： Junyi ma lin Yu Qing Yang Jie liu Lei Yang State Key Laboratory of materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430070China School of Transportation and Logistics Engineering Wuhan University of TechnologyWuhan430074China

Directed energy deposition-arc(DED-Arc)technology has the advantages of simple equipment,low manufacturing cost and high deposition rate,while the use of DED-Arc has problems of microstructure inhomogeneity,position dependence of macroscopic mechanical properties and ***,it is necessary to carry out a subsequent heat treatment to improve its microstructure uniformity,mechanical properties and *** this investigation,the DED-Arc 15-layer NiTi alloy thin-walled parts with the solution treatment at different process parameters were studied to analyze the effects of solution heat treatment on microstructure,phase composition,phase transformation,microhardness,tensile and *** temperature range of solution treatment is 800-1050℃,and the treatment time range is 1-5.5 *** results show that after solution treatment at 800℃/1 h,the content of precipitated phase decreases,the grain is refined,the microhardness increases,and the mechanical properties in the 0°direction are *** strain recovery rate after 10 tensile cycles has increased from 37.13%(as-built)to 49.25%(solid solution treatment).This research provides an effective post treatment method for high-performance DED-Arc NiTi shape memory alloys.

关键词： Directed energy deposition-arc(DED-Arc) Cold metal transfer(CMT) NiTi shape memory alloys Microstructure Phase transformation Solution heat treatment

Reference-input-based Imaginary Axis Current Estimation Method for DQ Control Strategy in Single-phase PWM Converters

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CSEE Journal of Power and Energy Systems 2024年第5期10卷 2079-2087页

作者： lin Peng Lei ma Wensheng Song Haoran liu School of Electrical Engineering Sichuan Polytechnic UniversityDeyang 618000China School of Electrical Engineering Southwest Jiaotong UniversityChengdu 611756China

For dq control strategies in single-phase pulse width modulation(PWM)converters,the-axis current must be created by imaginary axis current estimation(IACE)*** estimated error of the-axis current during the transient process causes d-q axis current loops to be incompletely decoupled,thereby affecting the dynamic performance of the current *** second-order generalized integrator(SOGI)method suffers from slow dynamic *** fictive-axis emulation(FAE)method provides fast dynamic response but it is sensitive to circuit parameters.A reference-input(RI)-based IACE method is proposed to overcome the above *** to the characteristic that the-axis current loop has no transient process,the-axis current is estimated by the d-q axis reference *** is equivalent to introducing the-axis reference input as a feedforward term into the d-q axis current loop,so the parameter sensitivity problem is solved,and the parameter tuning is not *** proposed method can maintain good steadystate performance and significantly improve the dynamic performance of the current ***,it is straightforward and can be easily implemented in digital *** hardware-in-the-loop(HIL)experimental comparisons with the SOGI and FAE methods have been conducted to verify the correctness and effectiveness of the proposed RI-based IACE method.

关键词： dq control dynamic response imaginary axis current estimation(IACE) single-phase PWM converter

Activation of hematite photoanode synthesized at low temperature by W doping

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Journal of Energy Chemistry 2024年第10期97卷 149-155,I0004页

作者： Changtong ma Dongfeng Li lin liu Xiuli Wang Hongxian Han State Key Laboratory of Catalysis and Dalian National Laboratory for Clean Energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences Beijing 100049China

*** Solar water splitting offers a promising approach for green hydrogen production[1].There are many ways to achieve solar water splitting,such as photocatalytic(PC)water splitting,photoelectrochemical(PEC)water spli... 详细信息

关键词： Hematite Solar water splitting Charge separation Charge transfer

Interaction between systemic iron parameters and left ventricular structure and function in the preserved ejection fraction population:a two-sample bidirectional Mendelian randomization study

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Journal of Geriatric Cardiology 2024年第1期21卷 64-80页

作者： Xiong-Bin ma Yong-Ming liu Yan-lin LV lin QIAN The First Clinical Medical College of Lanzhou University LanzhouGansuChina Geriatric Cardiovascular Department and Gansu Clinical Research Center for Geriatric Diseases First Hospital of Lanzhou UniversityGansuChina

BACKGROUND Left ventricular(LV)remodeling and diastolic function in people with heart failure(HF)are correlated with iron status;however,the causality is *** Mendelian randomization(MR)study investigated the bidirectional causal relationship between systemic iron parameters and LV structure and function in a preserved ejection fraction *** Transferrin saturation(TSAT),total iron binding capacity(TIBC),and serum iron and ferritin levels were extracted as instrumental variables for iron parameters from meta-analyses of public genome-wide association *** without myocardial infarction history,HF,or LV ejection fraction(LVEF)magnetic Resonance Imaging Study constituted the outcome *** dataset included LV end-diastolic volume,LV endsystolic volume,LV mass(LVM),and LVM-to-end-diastolic volume ratio(LVMVR).We used a two-sample bidirectional MR study with inverse variance weighting(IVW)as the primary analysis method and estimation methods using different algorithms to improve the robustness of the *** In the IVW analysis,one standard deviation(SD)increased in TSAT significantly correlated with decreased LVMVR(β=-0.1365;95%confidence interval[CI]:-0.2092 to-0.0638;P=0.0002)after Bonferroni ***,no significant relationships were observed between other iron and LV *** Bonferroni correction,reverse MR analysis showed that one SD increase in LVEF significantly correlated with decreased TSAT(β=-0.0699;95%CI:-0.1087 to-0.0311;P=0.0004).No heterogeneity or pleiotropic effects evidence was observed in the *** We demonstrated a causal relationship between TSAT and LV remodeling and function in a preserved ejection fraction population.

关键词： fraction function parameters

Predicting Acute Mountain Sickness Using Regional Sea-Level Cerebral Blood Flow

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Biomedical and Environmental Sciences 2024年第8期37卷 887-896页

作者： Hao Zhang Jie Feng Shiyu Zhang Wenjia liu lin ma Chinese PLA Medical School Beijing 100853China Department of Radiology First Medical CenterChinese PLA General HospitalBeijing 100853China Department of Radiology Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China

Objective To investigate the role of sea-level cerebral blood flow(CBF)in predicting acute mountain sickness(AMS)using three-dimensional pseudo-continuous arterial spin labeling(3D-pCASL).Methods Forty-eight healthy volunteers reached an altitude of 3,650 m by air after undergoing a head magnetic resonance imaging(MRI)including 3D-pCASL at sea *** CBF values of the bilateral anterior cerebral artery(ACA),middle cerebral artery(MCA),posterior cerebral artery(PCA),and posterior inferior cerebellar artery(PICA)territories and the laterality index(LI)of CBF were compared between the AMS and non-AMS *** analyses were performed to determine the relationship between CBF and AMS,and the predictive performance was assessed using receiver operating characteristic(ROC)*** The mean cortical CBF in women(81.65±2.69 mL/100 g/min)was higher than that in men(74.35±2.12 mL/100 g/min)(Pmay be used for prediction in male volunteers using non-invasive 3D-pCASL.

关键词： Acute mountain sickness High-altitude headache Cerebral blood flow Arterial spin labeling magnetic resonance imaging

Hollow Metal-Organic Framework/MXene/Nanocellulose Composite Films for Giga/Terahertz Electromagnetic Shielding and Photothermal Conversion

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Nano-Micro Letters 2024年第9期16卷 161-179页

作者： Tian mai Lei Chen Pei‑lin Wang Qi liu Ming‑Guo ma Research Center of Biomass Clean Utilization MOE Engineering Research Center of Forestry Biomass Materials and BioenergyBeijing Key Laboratory of Lignocellulosic ChemistryCollege of Materials Science and TechnologyBeijing Forestry UniversityBeijing 100083People’s Republic of China State Silica-Based materials Laboratory of Anhui Province Bengbu 233000People’s Republic of China

With the continuous advancement of communication technology,the escalating demand for electromagnetic shielding interference(EMI)materials with multifunctional and wideband EMI performance has become *** the electrical and magnetic components and designing the EMI material structure have attracted extensive interest,but remain a huge ***,we reported the alternating electromagnetic structure composite films composed of hollow metal-organic frameworks/layered MXene/nanocellulose(HMN)by alternating vacuum-assisted filtration *** HMN composite films exhibit excellent EMI shielding effectiveness performance in the GHz frequency(66.8 dB at Kaband)and THz frequency(114.6 dB at 0.1-4.0 THz).Besides,the HMN composite films also exhibit a high reflection loss of 39.7 dB at 0.7 THz with an effective absorption bandwidth up to 2.1 ***,HMN composite films show remarkable photothermal conversion performance,which can reach 104.6℃under 2.0 Sun and 235.4℃under 0.8 W cm^(−2),*** unique micro-and macrostructural design structures will absorb more incident electromagnetic waves via interfacial polarization/multiple scattering and produce more heat energy via the local surface plasmon resonance *** features make the HMN composite film a promising candidate for advanced EMI devices for future 6G communication and the protection of electronic equipment in cold environments.

关键词： Metal-organic frameworks MXene Nanocellulose Electromagnetic shielding Photothermal conversion

Confined Mn^(2+) enables effective aerobic oxidation catalysis

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Science China Chemistry 2024年第5期67卷 1545-1553页

作者： Desheng Yuan Sicong ma Xiao Kong Chi Zhang lin Chen Chengsheng Yang Lihua Wang Zhen liu lin Ye Yongmei liu Rui ma Zhi-Pan liu Yifeng Zhu Yong Cao Xinhe Bao Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China Department of Chemistry Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsCollaborative Innovation Center of Chemistry for Energy MaterialsFudan UniversityShanghai 200438China Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Institute of Advanced Fluorine-Containing materials Zhejiang Normal UniversityJinhua 321004China State Key Laboratory of Catalysis National Laboratory for Clean EnergyCollaborative Innovation Center of Chemistry for Energy MaterialsDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China

Effective and mild activation of O_(2) is essential but challenging for aerobic oxidation. In heterogeneous catalysis, high-valence manganese oxide(e.g., +4) is known to be active for the oxidation, whereas divalent MnO is ineffective due to its limited capacity to supply surface oxygen and its thermodynamically unstable structure when binding O_(2) in reaction conditions. Inspired by natural enzymes that rely on divalent Mn^(2+), we discovered that confining Mn^(2+) onto the Mn_(2)O_(3) surface through a dedicated calcination process creates highly active catalysts for the aerobic oxidation of 5-hydroxymethylfurfural, benzyl alcohol, and *** Mn_(2)O_(3)-confined Mn^(2+) is undercoordinated and efficiently mediates O_(2) activation, resulting in 2–3 orders of magnitude higher activity than Mn_(2)O_(3) alone. Through low-temperature infrared spectroscopy, we distinguished low-content Mn^(2+) sites at Mn_(2)O_(3) surface, which are difficult to be differentiated by X-ray photoelectron spectroscopy. The combination of in-situ energydispersive X-ray absorption spectroscopy and X-ray diffraction further provides insights into the formation of the newly identified active Mn^(2+) sites. By optimizing the calcination step, we were able to increase the catalytic activity threefold *** finding offers promising frontiers for exploring active oxidation catalysts by utilizing the confinement of Mn^(2+)and oftenignored calcination skills.

关键词： confinement catalysis manganese oxide aerobic oxidation divalent Mn^(2+) operando spectroscopies