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Effects of carbon content on the microstructure and tensile properties of a low-density steel

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 391-401页

作者： Yongxuan Shang Mingyu Fan Shuyong Jiang Zhongwu Zhang key laboratory of Superlight Materials and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China state key laboratory of Metal Material for Marine Equipment and Application Iron&Steel Research Institute of Ansteel Group CorporationAnshan 114009China

Carbon can change the phase components of low-density steels and influence the mechanical *** this study,a new method to control the carbon content and avoid the formation ofδ-ferrite by decarburization treatment was *** microstructural changes and mechanical characteristics with carbon content induced by decarburization were systematically ***-Jaoul(C-J)analysis was employed to examine the work hardening characteristics during the tensile *** decarburization by heat treatments,the carbon content within the austenite phase decreased,while Mn and Al were almost unchanged;this made the steel with full austenite transform into the austenite and ferrite dual ***,(Ti,V)C carbides existed in both matrix phase and the mole fraction almost the *** addition,the formation of other carbides *** loss induced a decrease in strength due to the weakening of the carbon solid *** the steel with the single austinite,the deformation mode of austenite was the dislocation planar glide,resulting in the formation of *** the dual-phase steel,the deformation occurred by the dislocation planar glide of austenite first,with the increase in strain,the cross slip of ferrite took place,forming dislocation cells in *** the late stage of deformation,the work hardening of austinite increased rapidly,while that of ferrite increased slightly.

关键词： low-density steels carbon content decarburization strengthening mechanisms work hardening behavior

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Stable copper boron–imidazolate cage as Cu-riched enzyme for highly efficient electrocatalytic CO2 reduction to ethylene

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Science China Chemistry 2025年

作者： Jun-Qiang Chen Qiao-Hong Li Qin-Long Hong Ping Shao Hai-Xia Zhang Jian Zhang state key laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

Single-atom catalyst has garnered widespread attention to mimic mature enzymes due to its well-defined atomic structure and coordination environments. However, since the carbon–carbon（C–C） coupling reactions require synergistic catalysis of multiple sites, single-atom catalysts suffer from insufficient active sites and unclear reaction mechanisms. Controlling the reaction intermediates in a precisely targeted pocket through careful metal–organic cage design is therefore crucial. Here, we prepare a tetrahedral [Cu6L4]-type boron–imidazolate cage integrating highly active Cu sites and optimized cavity, which exhibits enzyme like specific catalytic performance in electrochemical CO2reduction reaction（CO2RR） to enhance the selectivity of *** analyses and computational calculations suggest that the single Cu site together with neighboring boron–imidazolate ligands provides suitably synergistic effects that enable the energetically favorable formation of an *COCHO intermediate, a key step determining selectivity. As a result, the [Cu6L4]-type cage of BIC-145 achieves a Faradaic efficiency of 28% for C2H4maintaining an average current density of -3.54 mA cm-2over a 5-hour electrolysis period. This work represents the first example for studying single-metal site catalysts with ultra-low coordination numbers through the rational design of metal–organic cages.

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AQDS Enhances Degradation of BDE-47 by Promoting Shewanella oneidensis MR-1-mediated Fenton Reaction with Fe(III)-containing Minerals

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Journal of Earth Science 2025年

作者： Yongguang Jiang Siqi Zhu Zhou Jiang Yiran Dong Liang Shi School of Environmental Studies， China University of Geosciences state key laboratory of Biogeology and Environmental Geology， China University of Geosciences Hubei key laboratory of Yangtze Catchment Environmental Aquatic Science， China University of Geosciences state Environmental Protection key laboratory of Source Apportionment and Control of Aquatic Pollution， Ministry of Ecology and Environment， China University of Geosciences(Wuhan)

Electron shuttles are widespread in the environments and play important role in microbe-mineral interaction. This study investigated the effects of a model electron shuttle (i.e.， anthraquinone-2， 6-disulfonate， AQDS) on Shewanella oneidensis MR-1-mediated Fenton reaction and subsequent degradation of 2， 2′， 4， 4′-tetrabrominated diphenyl ether (BDE-47). Three Fe(III)-containing minerals， namely， ferrihydrite， goethite and nontronite， were used as electron acceptors and Fe(II) sources. With each mineral， additions of 0.01 – 1 mM AQDS in the reactions significantly enhanced Fe(III) reduction by S. oneidensis MR-1 and increased the amounts of Fe(II) produced in anoxic phase. As a result， the amounts of cumulative ·OH formed in oxic phase were increased by 10% – 287%. Regression analysis revealed that ·OH cumulation has significant linear correlation with sorbed Fe(II) but not aqueous and structural Fe(II). This finding may be ascribed to the higher reactivity of sorbed Fe(II) in oxygenation than the latter two types of Fe(II). With more ·OH， the degradation efficiency of BDE-47 was elevated by 31% – 173%. Collectively， AQDS enhances ·OH formation and BDE-47 degradation by promoting production of Fe(II)， particularly sorbed Fe(II) in S. oneidensis MR-1-mediated Fenton reaction with Fe(III)-containing minerals.

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E-PRedictor: an approach for early prediction of pull request acceptance

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Science China(Information Sciences) 2025年

作者： Kexing CHEN Lingfeng BAO Xing HU Xin XIA Xiaohu YANG state key laboratory of Blockchain and Data Security Zhejiang University Software Engineering Application Technology Lab

A pull request (PR) is an event in Git where a contributor asks project maintainers to review code he/she wants to merge into a project. The PR mechanism greatly improves the efficiency of distributed software development in the opensource community. Nevertheless, the massive number of PRs in an open-source software (OSS) project increases the workload of developers. To reduce the burden on developers, many previous studies have investigated factors that affect the chance of PRs getting accepted and built prediction models based on these factors. However, most prediction models are built on the data after PRs are submitted for a while (e.g., comments on PRs), making them not useful in practice. Because integrators still need to spend a large amount of effort on inspecting PRs. In this study, we propose an approach named E-PRedictor (earlier PR predictor) to predict whether a PR will be merged when it is created. E-PRedictor combines three dimensions of manual statistic features (i.e., contributor profile, specific pull request, and project profile) and deep semantic features generated by BERT models based on the description and code changes of PRs. To evaluate the performance of E-PRedictor, we collect475192 PRs from 49 popular open-source projects on GitHub. The experiment results show that our proposed approach can effectively predict whether a PR will be merged or not. E-PRedictor outperforms the baseline models (e.g., Random Forest and VDCNN) built on manual features significantly. In terms of F1@Merge, F1@Reject, and AUC (area under the receiver operating characteristic curve), the performance of E-PRedictor is 90.1%, 60.5%, and 85.4%, respectively.

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Preparation and study of novel mid-to-low-temperature phase-change molten salts

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Science China Technological Sciences 2025年

作者： Chenxing REN Yifan WANG Xin HE Chenghang ZHENG Xiang GAO state key laboratory of Clean Energy Utilization Zhejiang University Institute of Carbon Neutrality Zhejiang University Baima Lake laboratory Zhejiang University

Molten salts is a promising medium for heat storage and heat transfer due to their advantages of low cost, low steam pressure, high energy storage density and wide temperature range. In this paper, a new phase change mixture of molten salts with KNO3, NaNO3, ZnCl2, NaF, Na2CO3, NaCl, and MgO as materials has been prepared through a plenty of experiments. The experimental results show that the melting point of some molten salts can be reduced to 202.9°C, and the decomposition temperature can reach 701.3°C. In addition, its thermophysical properties, including specific heat, viscosity and thermal stability, were measured and analyzed. The average specific heat of some molten salts is as high as 2.53 J/（g K）, and the average thermal conductivity is as high as 0.77 W/（m K）. In the 4-day short-term thermal stability test, the fluctuation of each parameter is minimal, and the overall thermal physical property is relatively stable. Compared with the traditional phase change molten salt, the new hybrid molten salt has a significantly lower melting point, a further improvement in the decomposition temperature, specific heat and other comprehensive thermophysical properties, and a better overall economy, which has important application value in heat transfer and energy storage.

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High-precision magnetic field measurement system based on a coherent population trapping magnetometer onboard the SATech-01 satellite

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Science China Technological Sciences 2025年

作者： Hongbo XUE Wei SONG Haoran ZHAO Yiteng ZHANG Shanzhi YE Jindong WANG Ran TAO Peng SANG Keli CHEN Xingzi BI Bingjun CHENG Bin ZHOU Yongliang XUE Yingying TANG Liu LIU Jinsong LI Xiaocheng ZHU Baoquan LI Jinguo LIU Wen CHEN Xiaofeng ZHANG Yonghe ZHANG Lei LI state key laboratory of Space Weather National Space Science Center Chinese Academy of Sciences key laboratory of Solar Activity and Space Weather National Space Science Center Chinese Academy of Sciences key laboratory of Electronics and Information Technology for Space Systems National Space Science Center Chinese Academy of Sciences state key laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences Innovation Academy for Microsatellites Chinese Academy of Sciences

On July 27, 2022, a high-precision system for measuring the magnetic field based on a coherent population trapping magnetometer（referred to as the CPT system） was launched onboard the Space Advanced Technology demonstration satellite（SATech-01） by a ZK-1A rocket. The payload comprises a scalar coherent population trapping magnetometer（CPTM）, triaxial anisotropic magnetoresistance magnetometer（AMRM）, and nano star tracker mounted on a non-magnetic telescopic tubular mast. This configuration enables synchronized measurement of scalar and vector geomagnetic fields, as well as the attitude,making the payload with its compact sensors suitable for applications on miniature satellite platforms. On November 7, 2022,the novel telescopic tubular mast was deployed in orbit, extending to a length of 5.28 m. The CPTM, an absolute scalar magnetometer with an omnidirectional sensor, is the first China-developed quantum/atomic magnetometer successfully operating in space. In orbit, the CPTM has sensitivity of ～10 pT/Hz1/2and can automatically operate under complex magnetic field variations. The difference between the scalar fields obtained using the CPTM and CHAOS model has a mean deviation of–3.73 n T and a standard deviation of 26.11 nT（1σ）, without on-orbit calibration or correction. The miniaturized AMRM has a sensitivity of ～0.3 n T/Hz1/2and maintains stable and reliable operation in orbit. The low-power and miniaturized nano star tracker has a measurement uncertainty of 14.23″（1σ） in orbit. The mission has realized the on-orbit technical verification of the integrated and synchronized detection of the vector magnetic field and attitude and fully validated the system's performance,automation level, and reliability.

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MixerKT:A Knowledge Tracing Model Based on Pure MLP Architecture

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Computers, Materials & Continua 2025年第1期82卷 485-498页

作者： Jun Wang Mingjie Wang Zijie Li Ken Chen Jiatian Mei Shu Zhang key laboratory of Education Informatization for Nationalities Ministry of EducationYunnan Normal UniversityKunming650000China Yunnan key laboratory of Smart Education Yunnan Normal UniversityKunming650000China

In the field of intelligent education,the integration of artificial intelligence,especially deep learning technologies,has garnered significant *** tracing(KT)plays a pivotal role in this field by predicting students’future performance through the analysis of historical interaction data,thereby assisting educators in evaluating knowledgemastery and tailoring instructional *** knowledge tracingmethods,largely based on Recurrent Neural Networks(RNNs)and Transformer models,primarily focus on capturing long-term interaction patterns in sequential ***,these models may neglect crucial short-term dynamics and other relevant *** paper introduces a novel approach to knowledge tracing by leveraging a pure Multilayer Perceptron(MLP)*** proposeMixerKT,a knowledge tracing model based on theHyperMixer framework,which uniquely integrates global and localMixer feature *** architecture enables more effective extraction of both long-terminteraction trends and recent learning behaviors,addressing limitations in currentmodels thatmay overlook these key *** evaluations on twowidely-used datasets,ASSIS Tments2009 and Algebra2005,demonstrate that MixerKT consistently outperforms several state-of-the-art models,including DKT,SAKT,and Separated Self-Attentive Neural Knowledge Tracing(SAINT).Specifically,MixerKT achieves higher prediction accuracy,highlighting its effectiveness in capturing the nuances of learners’knowledge *** results indicate that our model provides a more comprehensive representation of student learning patterns,enhancing the ability to predict future performance with greater precision.

关键词： Knowledge tracing multilayer perceptron channel mixer sequence mixer

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Photoinduced radical sulfur dioxide insertion with asymmetric cyclization of alkenes: accessing β-chiral sulfones bearing S-stereocentric cyclic sulfinamides

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Science China Chemistry 2025年第1期68卷 257-263页

作者： Jiapian Huang Chenxin Wang Xu Wang Xiaoyu Zhou Wei Xiao Jie Wu School of Pharmaceutical and Chemical Engineering & Institute for Advanced Studies Taizhou University state key laboratory of Organometallic Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences School of Chemistry and Chemical Engineering Henan Normal University

The generation of various β-chiral sulfones bearing chiral cyclic sulfinamides through photoredox-catalyzed sulfur dioxide insertion with asymmetric radical cyclization is described. This method features a broad substrate scope and excellent stereospecificity. Computational studies reveal that the dispersion interaction between sulfinyl group and CH2SO2Ph group plays a crucial role in the stereoselectivity control.

关键词： β-chiral sulfones chiral cyclic sulfinamides sulfur dioxide insertion asymmetric radical cyclization stereoselectivity

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Research on the deformation mechanism of flexural toppling deep-seated landslides based on large centrifuge physical model testing: A case study of the Genie landslide in the Tibetan Plateau

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Journal of Earth Science 2025年

作者： Shichao Cao Xiujun Dong Changbao Guo Ruian Wu Zhihua Yang Guang Zheng Xiaoqiang Zhu state key laboratory of Geohazard Prevention and Geoenvironment Protection， Chengdu University of Technology Institute of Geomechanics， Chinese Academy of Geological Sciences key laboratory of Active Tectonics and Geological Safety， Ministry of Natural Resources

Flexural toppling is a widespread failure mode in natural and excavated anti-inclined rock slopes of the eastern Tibetan Plateau， which can further evolve into large deep-seated landslides， posing significant threats to the construction and operation of important infrastructure. In this study， we took the large deep-seated Genie landslide as a case study and established a centrifuge physical model to analyze the deformation mechanism and evolutionary process of flexural toppling deep-seated landslides under the effect of gravity. The results indicate that the geomechanical mode of landslide instability is characterized by flexural toppling-shearing-sliding， with the deformation process could be divided into three stages: initial slow deformation stage marked by crack generation， rapid deformation stage characterized by the expansion and fracturing of cracks， and a low-speed deformation stage characterized by creep. Notably， the sliding surfaces do not adhere strictly to predefined bending zones but develop cracks along the bending parts， which gradually expand and penetrate deeper， eventually forming multiple potential sliding surfaces. The analysis of the entire process deformation evolution of flexural toppling deep-seated landslides suggests that the rapid deformation stage is the optimal time to take action for landslide prevention and control. The study demonstrates that the shear strength also plays a key factor in the evolution of flexural toppling. The research reveals the deformation mechanism and evolutionary process of large deep-seated landslides in deep-cut canyon areas， providing valuable reference for the prediction， assessment， and prevention of such slopes and landslides.

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Dual-ligand chiral MOFs exhibiting circularly polarized room temperature phosphorescence for anti-counterfeiting

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Science China Chemistry 2025年

作者： Hongrui Zheng Qingqing Wang Xinchao Wang Fei Wang Shangda Li Jian Zhang state key laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences Fujian key laboratory of Polymer Materials College of Chemistry and Materials Science Fujian Normal University

Advanced chiral optical materials exhibiting circularly polarized room-temperature phosphorescence（CPRTP） possess significant research value. This study facilitates the synthesis of chiral metal-organic frameworks（CMOFs） with good CPRTP performance by implementing a dual-ligand strategy. By self-assembling the luminescent ligand H2BIIM with the chiral ligands L-or D-H2IDPA in the presence of Zn（II） ions, two robust three-dimensional（3D） CMOFs were successfully constructed. These complexes demonstrated intense fluorescence and exhibited prolonged yellow room-temperature phosphorescence（RTP） with a duration of up to 6 s. Notably, they exhibited both circularly polarized fluorescence(glum= ±7.57 × 10-3) and CPRTP(glum=±2.68 × 10-3). These unique properties were effectively utilized in the creation of multi-color anti-counterfeiting patterns,underscoring their promising potential for a wide range of applications.

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