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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1456-1461页

作者： Anran Zhang Xinquan zhou Ranran gu Zhiguo Xia State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied TechniquesSchool of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510641China School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510641China

Mn^(2+)doping has been adopted as an efficient approach to regulating the luminescence properties of halide perovskite nano-crystals(NCs).However,it is still difficult to understand the interplay of Mn^(2+)luminescence and the matrix self-trapped exciton(STE)emission *** this study,Mn^(2+)-doped CsCdCl_(3) NCs are prepared by hot injection,in which CsCdCl_(3) is selected because of its unique crystal structure suitable for STE *** blue emission at 441 nm of undoped CsCdCl_(3) NCs originates from the defect states in the ***^(2+)doping promotes lattice distortion of CsCdCl_(3) and generates bright orange-red light emission at 656 *** en-ergy transfer from the STEs of CsCdCl_(3) to the excited levels of the Mn^(2+)ion is confirmed to be a significant factor in achieving efficient luminescence in CsCdCl_(3):Mn^(2+)*** work highlights the crucial role of energy transfer from STEs to Mn^(2+)dopants in Mn^(2+)-doped halide NCs and lays the groundwork for modifying the luminescence of other metal halide perovskite NCs.

关键词： perovskite nanocrystals self-trapped excitons luminescence energy transfer

Effects of Ag addition on the microstructures and properties of Al–Mg–Si–Cu alloys

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International Journal of Minerals,Metallurgy and Materials 2018年第1期25卷 62-72页

作者： Li-zi He yi-heng Cao yi-zhou zhou Jian-zhong Cui Key Lab of Electromagnetic Processing of Materials Ministry of EducationNortheastern University School of Materials Science and Engineering Northeastern University Institute of Metal Research Chinese Academy of Sciences

Effects of Ag addition on the microsmactures, aging characteristics, tensile properties, electrochemical properties, and intergranu- lar corrosion （IGC） properties of Al 1.1Mg-0.8Si-0.9Cu-0.35Mn4）.02Ti alloy were investigated using scanning electronic microscopy and transmission electronic microscopy. The aging process of Al-Mg-Si-Cu alloys was accelerated by the addition of Ag. The strength of peak-aged Al-Mg-Si-Cu alloys was enhanced by Ag addition because of the high density of β＂- and L-phase age-hardening precipitates. The corrosion performance of the Al-Mg-Sii-Cu alloy is closely related to the aging conditions and is independent of the Ag content. The IGC susceptibility is serious in the peak-aged alloy because of the continuous distribution of Cu-rich Q-phase precipitates along grain boun- daries. Ag addition reduces the size of the grain-boundary-precipitate Q phase and the width of the precipitate-free zone and thus results in decreased IGC susceptibility of Al-Mg-Si Cu alloys.

关键词： Al-Mg-Si-Cu alloys silver addition aging tensile properties corrosion properties microstructures

Seismic risk assessment and damage analysis:Emerging trends and new developments

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Journal of Safety Science and Resilience 2024年第3期5卷 365-381页

作者： yi Liu yin gu Hui Zhang Instituteof Public Safety Researcheparmentof Engineering Physics inghua UniversityBejing100084China School of Safety Science Tsinghua UniversityBejing 100084China Beijing Key Laboratory of City Integrated Emergency Response Science Beijing 100084China

Earthquakes are major catastrophes that cause great life and economic losses to human society and *** paper reviews and synthesizes relevant studies,drawing from a systematic examination of 4229 articles from the Web of Science core collection(1982-2023).Employing the CiteSpace visualization and analysis tool,current research and emerging trends in seismic risk assessment are discussed and *** paper provides a holistic overview of principal contributions,knowledge sources,interdisciplinary characteristics,and principal research topics in this ***,we propose key technologies that are in urgent need of enhancement,including data availability,quantity and quality of data,interpretability of machine learning models,perfor-mance improvement of machine learning methods and application of foundation models,as well as real-time risk assessment *** insights support both theoretical understanding and practical applications of seismic risk assessment and damage analysis.

关键词： Earthquake Vulnerability Seismic risk assessment Seismic damage analysis CiteSpace

Machine learning-assisted systematical polymerization planning:case studies on reversible-deactivation radical polymerization

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Science China Chemistry 2021年第6期64卷 1039-1046页

作者： Yu gu Peirong Lin Chengda zhou Mao Chen State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200433China Department of Civil and Environmental Engineering Princeton UniversityNew Jersey 08544USA

The combined influence of chemical composition,molecular weight(MW)and molecular weight distribution(D)on the functions and performances of polymeric materials necessitates simultaneous satisfaction of multidimensional requirements during polymer ***,the complexity of polymerization reactions often dissuades chemists when precisely accessing diversified polymer ***,we developed a machine learning(ML)-assisted systematical polymerization planning(SPP)platform for addressing this *** ML model providing integrated navigation of the reaction space,this approach can conduct multivariate analysis to uncover complex interactions between the polymerization result and conditions,prescribing optimal reaction conditions to achieve discretionary polymer targets concerning three dimensions including chemical composition,MWandD *** the increasing importance of polymerization in advanced material engineering,this ML-assisted SPP platform provides a universal strategy to access tailored polymers with on-demand prediction of polymerization parameters.

关键词： polymerization synthetic methods synthesis planning photochemistry machine learning

Suppressing nonlinear aeroelastic response of laminated composite panels in supersonic airflows using a nonlinear energy sink

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Chinese Journal of Aeronautics 2021年第2期34卷 376-385页

作者： Jian zhou Minglong XU Zhichun YANG yingsong gu State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi'an Jiaotong UniversityXi'an 710049China School of Aeronautics Northwestern Polyteclmical UniversityXi'an 710072China

This paper proposes using a Nonlinear Energy Sink(NES) to suppress the nonlinear aeroelastic response of laminated composite panels in supersonic airflows. Relevant aeroelastic equations are established using Hamilton’s principle and a finite element approach, drawing upon Von Karman’s large deflection theory and first order piston theory. The idea of the NES suppression region is proposed and the effects of NES parameters on the NES suppression region are studied in detail. The results show that the nonlinear aeroelastic responses of the panel can be completely suppressed by the Transient Resonance Capture(TRC);the appropriate NES parameter values can increase the critical dynamic pressure for flutter and suppress the nonlinear aeroelastic response effectively. Increasing the mass ratio of the NES can improve the NES suppression region;the nonlinear stiffness coefficient and damping of the NES within a specific range can suppress the nonlinear aeroelastic response. The most effective installation position for a NES is in a specific region behind the center-line of the panel in the direction of the airflow.

关键词： Aeroelasticity Laminated composite panel Nonlinear dynamics Nonlinear energy sink Panel flutter Passive suppression

Facile synthesis of gradient copolymers enabled by droplet-flow photo-controlled reversible deactivation radical polymerization

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Science China Chemistry 2021年第5期64卷 844-851页

作者： Yang zhou Shantao Han Yu gu Mao Chen State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China

Monomer sequence influences the properties and applications of ***,massive efforts have been made to implement sequence control of *** this work,we developed a computer-aided droplet-flow polymerization based on photo-controlled reversible-deactivation radical polymerization(photo-RDRP),enabling synthesis of gradient copolymers of tunable sequential arrangements,low dispersity and good structural fidelity from various monomers without following their intrinsic reactivities,which is a key limitation in sequence *** obtained gradient copolymers exhibit unique thermal properties and stimulus responsiveness comparing with the random and block counterparts,and their glass transition behaviour could be regulated by the gradient *** believe that the unprecedented gradient photo-RDRP based on flow synthesis opens a robust and versatile avenue to streamline the synthesis of well-defined gradient polymers,and is compatible with other polymerization mechanisms.

关键词： controlled radical polymerization photopolymerization gradient copolymer flow chemistry sequence control

An efficient three-dimensional foil structure model for bump-type gas foil bearings considering friction

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Friction 2021年第6期9卷 1450-1463页

作者： Yongpeng gu Xudong LAN Gexue REN Ming zhou School of Aerospace Engineering Tsinghua UniversityBeijing 100084China

This paper presents an efficient three-dimensional(3D)structural model for bump-type gas foil bearings(GFBs)developed by considering *** foil structures are modeled with a 3D shell finite element *** the bump foil mechanical characteristics,the guyan reduction and component mode synthesis methods are adopted to improve computational efficiency while guaranteeing accurate static responses.A contact model that includes friction and separation behaviors is presented to model the interactions of the bump foil with the top foil and bearing *** proposed structural model was validated with published analytical and experimental *** coupled elastohydrodynamics model of GFBs was established by integration of the proposed structural model with data on hydrodynamic films,and it was validated by comparisons with existing experimental *** performance of a bearing with an angular misalignment was studied numerically,revealing that the reaction torques of the misaligned bearing predicted by GFB models with 2D and 3D foil structure models are quite *** 3D foil structure model should be used to study GFB misalignment.

关键词： gas foil bearing bump foil model frictional contact elastohydrodynamics bearing misalignment

A detailed investigation of low latitude tweek atmospherics observed by the WHU ELF/VLF receiver:Ⅰ. Automatic detection and analysis method

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Earth and Planetary Physics 2020年第2期4卷 120-130页

作者： RuoXian zhou XuDong gu KeXin Yang guangSheng Li BinBin Ni Juan yi Long Chen FuTai Zhao ZhengYu Zhao Qi Wang LiQing zhou Department of Space Physics School of Electronic InformationWuhan UniversityWuhan 430072China State Key Laboratory of Space Weather Chinese Academy of SciencesBeijing 100190China

As a dispersive wave mode produced by lightning strokes, tweek atmospherics provide important hints of lower ionospheric(i.e., D-region) electron density. Based on data accumulation from the WHU ELF/VLF receiver system, we develop an automatic detection module in terms of the maximum-entropy-spectral-estimation(MESE) method to identify unambiguous instances of low latitude *** justify the feasibility of our procedure through a detailed analysis of the data observed at the Suizhou Station(31.57°N, 113.32°E) on17 February 2016. A total of 3961 tweeks were registered by visual inspection;the automatic detection method captured 4342 tweeks, of which 3361 were correct ones, producing a correctness percentage of 77.4%(= 3361/4342) and a false alarm rate of 22.6%(= 981/4342).A Short-Time Fourier Transformation(STFT) was also applied to trace the power spectral profiles of identified tweeks and to evaluate the tweek propagation distance. It is found that the fitting accuracy of the frequency–time curve and the relative difference of propagation distance between the two methods through the slope and through the intercept can be used to further improve the accuracy of automatic tweek identification. We suggest that our automatic tweek detection and analysis method therefore supplies a valuable means to investigate features of low latitude tweek atmospherics and associated ionospheric parameters comprehensively.

关键词： tweeks automatic detection WHU-VLF receiver

Microbial remediation of aromatics-contaminated soil

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Frontiers of Environmental Science & Engineering 2017年第2期11卷 1-9页

作者： ying Xu Ning-yi zhou State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology Shanghai Jiao Tong University Shanghai 200240 China

Aromatics-contaminated soil is of particular environmental concern as it exhibits carcinogenic and mutagenic properties. Bioremediation, a biological approach for the removal of soil contaminants, has several advantages over traditional soil remediation methodologies including high efficiency, complete pollutant removal, low expense and limited or no secondary pollution. Bioaugmentation, defined as the introduction of specific competent strains or consortia of microorganisms, is a widely applied bioremediation technology for soil remediation. In this review, it is concluded which several successful studies of bioaugmentation of aromatics-contaminated soil by single strains or mixed consortia. In recent decades, a number of reports have been published on the metabolic machinery of aromatics degradation by microorganisms and their capacity to adapt to aromatics-contaminated environments. Thus, microorganisms are major players in site remediation. The bioremediation/bioaugmentation process relies on the immense metabolic capacities of microbes for transformation of aromatic pollutants into essentially harmless or, at least, less toxic compounds. Aromatics-contaminated soils are successfully remediated with adding not only single strains but also bacterial or fungal consortia. Furthermore several novel approaches, which microbes combined with physical, chemical or biological factors, increase remediatio.n efl~.ciency of aromatics-contaminated soil. Meanwhile, the environmental factors also have appreciable impacts on the bioaugmentation process. The biostatistics method is recommended for analysis of the effects of bioaugmentation treatments.

关键词： Aromatics-contaminated soilBacteriaBioaugmentationBioremediationFungi

Detection and significance of higher thiadiamondoids and diamondoidthiols in oil from the Zhongshen 1C well of the Tarim Basin, NW China

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Science China Earth Sciences 2018年第10期61卷 1440-1450页

作者： Anlai MA Zhijun JIN Cuishan ZHU yi gu Sinopec Petroleum Exploration & Production Research Institute Beijing 100083 China State Key Laboratory of Organic Geochemistry Guangzhou 510640 China College of Resources and Environment Yangtze UniversityWuhan 430100 China

Oil and gas breakthroughs have been achieved in the Zhongshen 1(ZS1) and 1 C(ZS1 C) wells in Cambrian pre-salt from the Tarim Basin in northwest China. However, Middle and Lower Cambrian reservoirs reveal substantial differences in the geochemistry and secondary alteration characteristics between the oils collected from the two wells. High concentrations of thiadiamondoids and diamondoidthiols, including thiatetramantanes, tetramantanethiols, thiapentamantanes, and pentamantanethiols, are detected in the organic sulfur compound fraction of concentrated oil collected from the ZS1 C well, which samples the Lower Cambrian Xiaoerbulake Formation. Higher diamondoids, such as tetramantanes, pentamantanes, hexamantanes, and cyclohexamantane, also occur in the saturate fractions of the concentrated ZS1 C oil. The presence of these compounds is verified by mass spectra analysis and comparison with previous studies. During thermochemical sulfate reduction(TSR), the cage of higher diamondoids is interpreted to open because of sulfur radicals forming open-cage higher diamondoid-like thiols, followed by cyclization that leads to the formation of high thiadiamondoids. Using D_(16)-adamantane as an internal standard, the concentrations of lower diamondoids and thiadiamondoids of non-concentrated Cambrian oil from well ZS1 C are 83874 and8578 μg/g, respectively, which are far higher than Cambrian oil from well ZS1 and most Ordovician oils in the Tarim Basin. The high concentrations of lower thiadiamondoids and occurrence of higher thiadiamondoids and diamondoidthiols support that the oil from well ZS1 C is a product of severe TSR alteration.

关键词： Tarim Basin Cambrian Well Zhongshen 1C Higher thiadiamondoid Higher diamondoidthiol Higher diamondoid,Therrnochemical sulfate reduction (TSR)