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Evolution of plasticized MnO–Al2O3–SiO2-based nonmetallic inclusion in 18wt%Cr-8wt% Ni stainless steel and its properties during soaking process

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International Journal of Minerals,Metallurgy and Materials 2020年第3期27卷 328-339页

作者： Jing guo Xing-run Chen Shao-wei Han yan yan Han-jie guo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Jiuquan Iron and Steel Group Corporation Jiayuguan 735100China Beijing Shougang Co.Ltd. Qian'an 064400China

The properties of MnO–Al2O3–SiO2-based plasticized inclusion are likely to change during soaking process due to its low melting point. In this study, the evolution of the MnO–Al2O3–SiO2-based inclusion of 18 wt%Cr-8 wt%Ni stainless steel under isothermal soaking process at 1250°C for different times was investigated by laboratory-scale experiments and thermodynamic analysis. The results showed that the inclusion population density increased at the first stage and then decreased while their average size first decreased and then increased. In addition, almost no Cr2O3-concentrated regions existed within the inclusion before soaking, but more and more Cr2O3 precipitates were formed during soaking. Furthermore, the plasticity of the inclusion deteriorated due to a decrease in the amount of liquid phase and an increase in the high-melting-pointphase MnO–Cr2O3 spinel after the soaking process. In-situ observations by high-temperature confocal laser scanning microscopy(CLSM) confirmed that liquid phases were produced in the inclusions and the inclusions grew rather quickly during the soaking process. Both the experimental results and thermodynamic analysis conclude that there are three routes for inclusion evolution during the soaking process. In particular, Ostwald ripening plays an important role in the inclusion evolution, i.e., MnO–Al2O3–SiO2-based inclusions grow by absorbing the newly precipitated smaller-size MnO–Cr2O3 inclusions.

关键词： nonmetallic inclusion soaking process Ostwald ripening stainless steel

Development of a novel Eu^(3+)-doped tantalate red-emitting phosphor for w-LEDs application

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Journal of Rare Earths 2024年第8期42卷 1479-1488,I0003页

作者： Fan Zeng Jingjing ru Bing Zhao Feiyun guo Jianzhong Chen College of Chemistry and Materials Fujian Province University Key Laboratory of Green Energy and Environment CatalysisNingde Normal University.Ningde352100China School of Environment and Resources School of Carbon Neutral and Modern IndustryFujian Normal UniversityFuzhou350007China College of Information and Mechanical&Electrical Engineering Ningde Normal UniversityNingde352100China College of Chemistry Fuzhou UniversityFuzhou350108China

Two novel phosphors LiBa_(4(1-x))Eu_(4x)Ta_(3)O_(12)(H-LBTO:xEu^(3+)) and Li_(0.25)Ba_(1-x)Eu_(x)Ta_(0.75)O_(3)(C-LBTO:xEu^(3+))were prepared successfully by a molten salt *** transformation between these two structures was realized by changing the sintering temperature or changing the Eu^(3+) ions concentration,which was also demonstrated by the X-ray diffraction(XRD),scanning electron microscopy(SEM),diffuse reflectance spectra(DRS),and photoluminescence excitation(PLE) analyses,Both the sintering temperature and the Eu^(3+)ions doping concentration have significant impact on the formation of the crystal *** these phosphors sintered at 1023 K exhibit two major luminescence lines at 594 and 614 nm under nearuV light of 395 nm excitation,corresponding to Eu^(3+)ions typical transitions of ^(5)D_(0)→^(7)F_(1) and ^(5)D_(0)→^(7)F_(2).The optimum concentration of Eu^(3+) ions is 9 mol% for C-LBTO:xEu^(3+) samples and the quenching interaction type is the nearest-neighbor ion *** thermal stability of the C-LBTO:0.09Eu^(3+)sample was investigated in detail and the device application further suggests that C-LBTO:0.09Eu^(3+) can be used as a red phosphor for near-UV excited w-LEDs in lighting.

关键词： Phosphor Tantalate LED device Rare earths

Numerical simulation of pedestrian flow past a circular obstruction

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Acta Mechanica Sinica 2011年第2期27卷 215-221页

作者： yan-Qun Jiang ru-Xun Liu Ya-Li Duan Department of Mathematics Southwest University of Science and Technology 621010 Mianyang China Department of Mathematics University of Science and Technology of China 230026 Hefei China

In this paper, a revisiting Hughes’ dynamic continuum model is used to investigate and predict the essential macroscopic characteristics of pedestrian flow, such as flow, density and average speed, in a two dimensional continuous walking facility scattered with a circular obstruction. It is assumed that pedestrians prefer to walk a path with the lowest instantaneous travel cost from origin to destination, under the consideration of the current traffic conditions and the tendency to avoid a high-density region and an obstruction. An algorithm for the pedestrian flow model is based on a cellcentered finite volume method for a scalar conservation law equation, a fast sweeping method for an Eikonal-type equation and a second-order TVD runge-Kutta method for the time integration on unstructured meshes. Numerical results demonstrate the effectiveness of the algorithm. It is verified that density distribution of pedestrian flow is influenced by the position of the obstruction and the path-choice behavior of pedestrians.

关键词： Pedestrian flow · Continuum model ·Finite volume method · Unstructured meshes · Obstruction

Is it time to put traditional cold therapy in rehabilitation of soft-tissue injuries out to pasture?

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World Journal of Clinical Cases 2021年第17期9卷 4116-4122页

作者： Zi-ru Wang guo-Xin Ni School of Sports Medicine and Rehabilitation Beijing Sport UniversityBeijing 100084China

Cold therapy has been used regularly as an immediate treatment to induce analgesia following acute soft-tissue injuries,however,a prolonged ice application has proved to delay the start of the healing and lengthen the recovery *** gaseous cryotherapy,also known as neurocryostimulation,has shown the ability to overcome most of the limitations of traditional cold therapy,and meanwhile promotes the analgesic and anti-inflammatory effects well,but the current existing studies have shown conflicting results on its *** cold therapy still has beneficial effect especially when injuries are severe and swelling is the limiting factor for recovery after soft-tissue injuries,and therefore no need to be entirely put out to pasture in the rehabilitation *** randomized controlled trials with good methodological quality are still needed in the future to evaluate the effects of different cryotherapy modalities.

关键词： Cryotherapy Hyperbaric gaseous cryotherapy Neurocryostimulation Cold therapy Soft tissue injury

Characterization of Formation Kinetics of Self-Assembled Thiol Monolayers on Gold by Electrochemical Impedance Spectroscopy

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Chinese Chemical Letters 2000年第12期11卷 1085-1088页

作者： Peng DIAO Min guo ru Ting TONG Department of Chemistry Hebei Teacher’s UniversityShijiazhuang 050016 Department of Traditional Chinese Pharmacy Traditional Chinese Medicine CollegeHebei Medical UniversityShijiazhuang 050091

Self-assembled monolayers of octadecanethiol (ODT) on gold have been studied by electrochemical impedance spectroscopy (EIS). The fractional coverage has been examined as a function of immersion time of Au in ODT deposition solution. The fractional coverage exhibits two distinct adsorption steps: an initial rapid step followed by a slow one. The fractional coverage of ODT monolayer increases sharply from zero to more than 99% of its maximum within the first minute. However. it takes a day for the fractional coverage to approach its final value.

关键词： self-assembled thiol monolayer electrochemical impedance spectroscopy adsorption kinetics

Phase stability and hardness of some ternary Ti-Zr based shape memory alloys

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International Journal of Smart and Nano Materials 2011年第4期2卷 272-282页

作者： yan Li Zhifang ru yan Cui Kun Luo School of Materials Science and Engineering Beihang UniversityBeijing 100191China Beijing Key Laboratory for Advanced Functional Materials and Thin Film Technology Beihang UniversityBeijing 100191China Key Laboratory of Aerospace Materials and Performance(Ministry of Education) School of Materials Science and EngineeringBeihang UniversityBeijing 100191China

The phase stability and hardness of Ti–30Zr–M(M=Nb,V,Cr,Mo,Fe,Ni and Al)shape memory alloys were investigated by structural observations,d-electron alloy design and microhardness *** microscopy and X-ray diffraction results show that Nb,V,Cr,Mo and Fe are allβ-stability elements in Ti–30Zr–M alloys with the effect enhanced by the presence of *** composition of the least stableβ-phase alloy values of Nb,V,Cr,Mo and Fe in Ti–30Zr alloys are 12%,9%,5%,3%and 2%,respectively,indicating an increasing sequence of theβ-stability *** and Al showα-stability or moderate effects and the addition of Ni induces the appearance of(Ti,Zr)_(2)Ni phase in Ti–30Zr–5/15Ni *** on the d-electron alloy design method,the bond order of Ti and alloying atoms(Bo)and the metal d-orbital energy level(Md)are calculated to build the Bo–Md diagram of Ti–30Zr–M alloys associated with the phase structure *** microhardness of Ti–30Zr alloy is increased by addition of a small amount of the alloying element,except for *** is a drop of the microhardness of each Ti–30Zr–M alloys whenβphase appears by the addition of more alloying elements.

关键词： Ti-Zr shape memory alloy microstructure martensitic transformation d-electron alloy design

Bug localization based on syntactical and semantic information of source code

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Journal of Systems Engineering and Electronics 2023年第1期34卷 236-246页

作者： yan Xuefeng CHENG Shasha guo Liqin College of Computer Science Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China Collaborative Innovation Center of Novel Software Technology and Industrialization Nanjing 211106China State Key Laboratory of Intelligent Manufacturing System Technology Beijing Institute of Electronic System EngineeringBeijing 100854China

The existing software bug localization models treat the source file as natural language, which leads to the loss of syntactical and structure information of the source file. A bug localization model based on syntactical and semantic information of source code is proposed. Firstly, abstract syntax tree(AST) is divided based on node category to obtain statement sequence. The statement tree is encoded into vectors to capture lexical and syntactical knowledge at the statement ***, the source code is transformed into vector representation by the sequence naturalness of the statement. Therefore,the problem of gradient vanishing and explosion caused by a large AST size is obviated when using AST to the represent source code. Finally, the correlation between bug reports and source files are comprehensively analyzed from three aspects of syntax, semantics and text to locate the buggy code. Experiments show that compared with other standard models, the proposed model improves the performance of bug localization, and it has good advantages in mean reciprocal rank(MRR), mean average precision(MAP) and Top N Rank.

关键词： bug report abstract syntax tree code representation software bug localization

Performance improvement of licklider transmission protocol in complex deep space networks based on parameter optimization

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Chinese Journal of Aeronautics 2023年第5期36卷 406-420页

作者： guo YU Zhenxing DONG yan ZHU Key Laboratory of Electronics and Information Technology for Space Systems National Space Science CenterChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

A reasonable parameter configuration helps improve the data transmission performance of the Licklider Transmission Protocol(LTP).Previous research has focused mainly on parameter optimization for LTP in simplified scenarios with one to two hops or multihop scenarios with a custody mechanism of the Bundle Protocol(BP).However,the research results are not applicable to communications in Complex Deep Space Networks(CDSNs)without the custody mechanism of BP that are more suitable for deep space communications with *** this paper,we propose a model of file delivery time for LTP in *** on the model,we propose a Parameter Optimization Design Algorithm for LTP(LTP-PODA)of configuring reasonable parameters for *** results show that the accuracy of the proposed model is at least 6.47%higher than that of the previously established models based on simple scenarios,and the proposed model is more suitable for ***,the LTP parameters are optimized by the LTP-PODA algorithm to obtain an optimization *** the optimization plan for LTP improves the protocol transmission performance by at least 18.77%compared with configuring the other parameter configuration plans.

关键词： Complex deep space networks File delivery time model Licklider Transmission Protocol(LTP) Network Performance Network Protocols Parameter optimization Performance improvement

Modeling and control of a novel electro-hydrostatic actuator with adaptive pump displacement

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Chinese Journal of Aeronautics 2020年第1期33卷 365-371页

作者： yan WANG Shengrong guo Hongkang DONG School of Transportation Science and Engineering Beihang UniversityBeijing 100083China Nanjing Engineer Institute of Aircraft System Jincheng AVICNanjing 211100China

The variable pump displacement and variable motor speed electro-hydrostatic actuator(EHA),one of the three types of EHAs,has advantages such as short response time,flexible speed regulation,and high ***,the nonlinearity of its double-input single-output system poses a great challenge for system *** study proposes a novel EHA with adaptive pump displacement and variable motor speed(EHA-APVM).A closed-loop position is realized using a ***,the displacement varies with the system pressure;thus,the EHA-APVM is a single-input and single-output ***,the working principles of the EHA-APVM and the pump used in the system are ***,a nonlinear mathematical model of the proposed EHA-APVM control system is established,and a feedback back-stepping(FBBS)control algorithm is introduced to transform the complex nonlinear system into a linear system on the basis of the back-stepping control ***,simulation results prove that the EHA-APVM has a quick response and high robustness to variations of the load and the pump *** this work,the size and weight of the motor are significantly reduced because the maximum power requirement is reduced,which is very beneficial for using the actuator in airborne equipment.

关键词： Adaptive displacement pump Back-stepping control Electro-hydrostatic actuator Feedback linearization Robustness