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A hazard analysis via an improved timed colored petri net with time–space coupling safety constraint

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Chinese Journal of Aeronautics 2016年第4期29卷 1027-1041页

作者： Li Zelin wang shihai Zhao Tingdi Liu Bin Science and Technology on Reliability and Environmental Engineering Laboratory School of Reliability and Systems Engineering Beihang University

Petri nets are graphical and mathematical tools that are applicable to many systems for modeling, simulation, and analysis. With the emergence of the concept of partitioning in time and space domains proposed in avionics application standard software interface (ARINC 653), it has become difficult to analyze time–space coupling hazards resulting from resource partitioning using classical or advanced Petri nets. In this paper, we propose a time–space coupling safety constraint and an improved timed colored Petri net with imposed time–space coupling safety constraints (TCCP-NET) to fill this requirement gap. Time–space coupling hazard analysis is conducted in three steps: specification modeling, simulation execution, and results analysis. A TCCP-NET is employed to model and analyze integrated modular avionics (IMA), a real-time, safety-critical system. The analysis results are used to verify whether there exist time–space coupling hazards at runtime. The method we propose demonstrates superior modeling of safety-critical real-time systems as it can specify resource allocations in both time and space domains. TCCP-NETs can effectively detect underlying time–space coupling hazards. © 2016 Chinese Society of Aeronautics and Astronautics

关键词： Application programs Avionics Hazards Interactive computer systems Petri nets Resource allocation Safety engineering

Model-based robustness testing for avionics-embedded software

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Chinese Journal of Aeronautics 2013年第3期26卷 730-740页

作者： Yang Shunkun Liu Bin wang shihai Lu Minyan School of Reliability and Systems Engineering Beihang University Science & Technology on Reliability & Environmental Engineering Laboratory

Robustness testing for safety-critical embedded software is still a challenge in its nascent stages. In this paper, we propose a practical methodology and implement an environment by employing model-based robustness testing for embedded software systems. It is a system-level black-box testing approach in which the fault behaviors of embedded software is triggered with the aid of modelbased fault injection by the support of an executable model-driven hardware-in-loop （HIL） testing environment. The prototype implementation of the robustness testing environment based on the proposed approach is experimentally discussed and illustrated by industrial case studies based on several avionics-embedded software systems. The results show that our proposed and implemented robustness testing method and environment are effective to find more bugs, and reduce burdens of testing engineers to enhance efficiency of testing tasks, especially for testing complex embedded systems.

关键词： Embedded software Hardware-in-loop Model-based testing Robustness testing Testing environment

Effects of substituting Ni with M (M=Cu, Al and Mn) on microstructures and electrochemical characteristics of La-Mg-Ni system (PuNi_3-type) electrode alloys

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Rare Metals 2006年第z1期25卷 25-32页

作者： ZHANG Yanghuan ZHAO Dongliang DONG Xiaoping REN Huiping GUO shihai wang Xinlin Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China School of Material Inner Mongolia University of Science and Technology Baotou 014010 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China School of Material University of Science and Technology Beijing Beijing 100083 China School of Material Inner Mongolia University of Science and Technology Baotou 014010 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China

In order to improve the electrochemical cycle stability of La-Mg-Ni system (PuNi3-type) hydrogen storage alloy, Ni in the alloys was partially substituted by M (M=Cu, Al, Mn). A new La-Mg-Ni system electrode alloys La0.7Mg0.3Ni2.55-xCo0.45Mx (M=Cu, Al, Mn; x=0, 0.1) were prepared by casting and rapid quenching. The effects of element substitution and rapid quenching on the microstructures and electrochemical performances of the alloys were investigated. The results by XRD, SEM and TEM show that the alloys have a multiphase structure, including the (La, Mg)Ni3 phase, the LaNi5 phase and the LaNi2 phase. The rapid quenching and element substitution have an imperceptible influence on the phase compositions of the alloys, but both change the phase abundance of the alloys. The rapid quenching significantly improves the composition homogeneity of the alloys and markedly decreases the grain size of the alloys. The Cu substitution promotes the formation of an amorphous phase in the as-quenched alloy, and a reversal result by the Al substitution. The electrochemical measurement indicates that the element substitution decreases the discharge capacity of the alloys, whereas it obviously improves the cycle stability of the alloys. The positive influence of element substitution on the cycle life of the alloys is in sequence Al>Cu>Mn, and negative influence on the discharge capacity is in sequence Al>Mn>Cu. The rapid quenching significantly enhances the cycle stability of the alloys, but it leads to a different extent decrease of the discharge capacity of the alloys.

关键词： element substitution rapid quenching La-Mg-Ni system electrode alloy microstructures electrochemical performances

Effects of Nd^(3+)on the microstructure and magnetic properties of Ni-Zn ferrites

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Rare Metals 2008年第3期27卷 287-291页

作者： FAN Xiufeng REN Huiping ZHANG Yanghuan GUO shihai wang Xinlin Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China School of Material and Metallurgy lnnerMongolia University of Science and Technology Baotou 014010 China

Ni0.4Zn0.6Fe2-xNdxO4（x = 0-0.07） ferrites doped with different amounts of Nd2O3 were prepared using standard ceramic technique. The samples were uniaxially pressed and sintered at 1250℃ for 4 h in air. The phase structure and microstructure of the samples were investigated using X-ray diffraction and scanning electron microscope, respectively. The complex permeability was measured using the impedance analyzer in the range of 1-100 MHz. The results indicate that with increasing Nd^3＋ content, the relative density and lattice parameter a of the sintered samples increase, whereas the real part of permeability （μ′） and the magnetic loss tangent （tan δ） decrease. The substitution of Nd^3＋ for Fe^3＋ forms a secondary phase on the grain boundary of the matrix, which strongly restrains the grain growth of the matrix.

关键词： Ni-Zn ferrite microstructure complex permeability relative density

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文学史中《红楼梦》阐释的再评估

首都师范大学学报（社会科学版） 2017年第6期 112-118页

作者：王世海厦门大学嘉庚学院

《红楼梦》作为中国文学史的叙述重点,较能反映出文学史编写的诸多问题。比较三种具有代表性的中国文学史著作对《红楼梦》的阐释,可见出文学史的编写应主要处理好三个问题:一是历史陈述与文本阐释的统一,二是文学史叙述逻辑和结构模式... 详细信息

《红楼梦》作为中国文学史的叙述重点,较能反映出文学史编写的诸多问题。比较三种具有代表性的中国文学史著作对《红楼梦》的阐释,可见出文学史的编写应主要处理好三个问题:一是历史陈述与文本阐释的统一,二是文学史叙述逻辑和结构模式的确立,三是文本、阐释与接受者之间关系的恰当处理。

关键词：《红楼梦》文学史编写文本阐释叙述逻辑接受者

基于AADL体系结构模型的构件系统可靠性评估

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系统工程与电子技术 2017年第4期39卷 947-952页

作者：凌冬怡王世海刘斌北京航空航天大学可靠性与系统工程学院北京100191

为了支持新一代航电系统在体系结构设计阶段进行系统可靠性分析和评估,对复杂嵌入式系统利用体系结构分析与设计语言(architecture analysis and design language,AADL)进行系统的建模。提出了一种基于AADL系统体系结构模型的可靠性建... 详细信息

为了支持新一代航电系统在体系结构设计阶段进行系统可靠性分析和评估,对复杂嵌入式系统利用体系结构分析与设计语言(architecture analysis and design language,AADL)进行系统的建模。提出了一种基于AADL系统体系结构模型的可靠性建模方法,设计出一套转换规则,对AADL体系结构模型的软硬件构件进行模型转换,实现从AADL系统体系结构可靠性模型到系统体系结构广义随机Petri网(system architecture general stochastic Petri net,SAGSPN)的转换,并基于加权的SAGSPN可靠性计算模型对系统进行可靠性评估。最后通过对某飞控系统进行可靠性评估,验证了方法的有效性,证明该方法对航电系统的体系结构设计提供了支持。

关键词：体系结构分析与设计语言可靠性模型系统体系结构广义随机Petri网可靠性评估

超小规模农业家庭经营模式也存在继承效应吗——基于鲁皖两省农户家庭父子两代匹配调查数据的实证

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农业技术经济 2024年第10期 55-69页

作者：王士海曹硕安徽农业大学经济管理学院合肥230036

本文利用山东省和安徽省的农村家庭父子两代匹配调查数据,采用离散选择模型和半非参数模型估计方法检验中国超小规模农业家庭经营模式的继承效应。研究结果表明,农业代际继承对家庭土地规模扩张呈显著正向影响,但对农机具购置的影响不显... 详细信息

本文利用山东省和安徽省的农村家庭父子两代匹配调查数据,采用离散选择模型和半非参数模型估计方法检验中国超小规模农业家庭经营模式的继承效应。研究结果表明,农业代际继承对家庭土地规模扩张呈显著正向影响,但对农机具购置的影响不显著;平原地区农户无论在土地规模扩张还是农机具购置上都没有呈现出显著的继承效应,而丘陵山区农户在两个方面都有显著的继承效应;继承效应具有一定的经营规模门槛,无论是经营规模还是农机具购置,只有那些经营规模超过0.8公顷的农户呈现出显著的继承效应,而经营规模小于或等于0.8公顷的农户在两个方面的继承效应均不显著;父代进入中期老龄化阶段和有青年人务农的家庭会呈现出更加显著的继承效应。小规模农户的继承人对经营规模和农业机械购入效应不显著的主要原因是,这些农户会继续保持兼职的特征,农外收入是其主要收入来源。本文能够为优化农业生产者支持政策和优化农业经营体系提供一定的决策参考。

关键词：农业家庭经营继承效应规模经营

S-M(M=Cu,Co,Ti)复合掺杂层状LiMnO_2的合成及其电化学性能

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化学学报 2009年第21期67卷 2413-2420页

作者：粟智叶世海王永龙新疆师范大学生命科学与化学学院乌鲁木齐830054 南开大学化学学院新能源材料化学研究所天津300071

用水热法合成了锂离子电池正极材料正交结构LiMnO_2材料,并对其进行S^(2-)、大尺寸阳离子(Cu^(2+),Co^(3+),Ti^(4+))以及硫-金属离子复合掺杂改性.用X射线衍射(XRD)、X光电子能谱分析(XPS)、透射电子显微镜(TEM)、恒电流充放电、交流阻... 详细信息

用水热法合成了锂离子电池正极材料正交结构LiMnO_2材料,并对其进行S^(2-)、大尺寸阳离子(Cu^(2+),Co^(3+),Ti^(4+))以及硫-金属离子复合掺杂改性.用X射线衍射(XRD)、X光电子能谱分析(XPS)、透射电子显微镜(TEM)、恒电流充放电、交流阻抗谱(EIS)等测试技术进行表征.实验结果表明:当掺入离子的含量较低时,得到的产物能保持完整的正交结构,并表现出较好的电化学性能.S^(2-)和非Jahn-Teller效应大尺寸阳离子的掺入使材料的循环稳定性能大幅度提高,而这种提高是源于这些离子对LiMnO_2结构的稳定作用.电极材料Li_(1.02)Mn_(0.988)Ti_(0.012)O_(1.989)S_(0.011)显示了最优的电化学性能,在50 mA·g^(-1)放电速率下,其初始放电容量为142.6 mAh·g^(-1),60次循环后放电容量为213.4 mAh·g^(-1).硫-金属阳离子复合掺杂,综合了大尺寸阳离子可以提高材料中Li^+的扩散能力和S^(2-)掺杂抑制,Jahn-Teller畸变两方面优势,使层状结构LiMnO_2,正极材料既保持了较高的容量又获得良好的循环性能.

关键词：水热合成正交结构正极材料复合掺杂

A fundamental theorem for eco-environmental surface modelling and its applications

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Science China Earth Sciences 2020年第8期63卷 1092-1112页

作者： Tianxiang YUE Na ZHAO Yu LIU Yifu wang Bin ZHANG Zhengping DU Zemeng FAN Wenjiao SHI Chuanfa CHEN Mingwei ZHAO Dunjiang SONG shihai wang Yinjun SONG Changqing YAN Qiquan LI Xiaofang SUN Lili ZHANG Yongzhong TIAN Wei wang Ying’an wang Shengnan MA Hongsheng HUANG Yimin LU Qing wang Chenliang wang Yuzhu wang Ming LU Wei ZHOU Yi LIU Xiaozhe YIN Zong wang Zhengyi BAO Miaomiao ZHAO Yapeng ZHAO Yimeng JIAO Ufra NASEER Bin FAN Saibo LI Yang YANG John PWILSON State Key L aboratory of Resources and Environment Information System Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China College of Land Resources and Environment Jiangxi Agricultural UniversityNanchang 330045China College of Geomatics Shandong University of Science and TechnologyQingdao 266590China College of Forestry Beijing Forestry UniversityBeijing 100083China School of Land and Resources China West Normal UniversityNanchong 637002China College of Geographical Information and Tourism Chuzhou UniversityChuzhou 239000China Institutes of Science and Development Chinese Academy of SciencesBeijing 100190China Department of Information Engineering Shandong University of Science and TechnologyTai'an 271019China College of Resources Sichuan Agricultural UniversityChengdu 611130China College of Geography and Tourism Qufu Normal UniversityRizhao 276828China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100101China School of Geographical Science Southwest UniversityChongqing 400715China National Disaster Reduction Center of China Ministry of Emergency ManagementBeijing 100721China Department for Population Data China Population and Development Research CenterBeijing 100081China Department for Industrial Standard China Standardization AdministrationBeijing 100088China The Academy of Digital China Fuzhou UniversityFuzhou 350002China National Institute of Environmental Health Chinese Center for Disease Control and PreventionBeijing 100021China School of Information Engineering China University of GeoscienceBeijing 100083China Qian Xuesen Laboratory of Space Technology Beijing 100094China College of Architecture and Urban Planning Chongqing Jiaotong UniversityChongqing 400074China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing

We propose a fundamental theorem for eco-environmental surface modelling(FTEEM) in order to apply it into the fields of ecology and environmental science more easily after the fundamental theorem for Earth’s surface system modeling(FTESM). The Beijing-Tianjin-Hebei(BTH) region is taken as a case area to conduct empirical studies of algorithms for spatial upscaling, spatial downscaling, spatial interpolation, data fusion and model-data assimilation, which are based on high accuracy surface modelling(HASM), corresponding with corollaries of FTEEM. The case studies demonstrate how eco-environmental surface modelling is substantially improved when both extrinsic and intrinsic information are used along with an appropriate method of HASM. Compared with classic algorithms, the HASM-based algorithm for spatial upscaling reduced the root-meansquare error of the BTH elevation surface by 9 m. The HASM-based algorithm for spatial downscaling reduced the relative error of future scenarios of annual mean temperature by 16%. The HASM-based algorithm for spatial interpolation reduced the relative error of change trend of annual mean precipitation by 0.2%. The HASM-based algorithm for data fusion reduced the relative error of change trend of annual mean temperature by 70%. The HASM-based algorithm for model-data assimilation reduced the relative error of carbon stocks by 40%. We propose five theoretical challenges and three application problems of HASM that need to be addressed to improve FTEEM.

关键词： HASM FTEEM Spatial upscaling Spatial downscaling Spatial interpolation Data fusion Model-data assimilation Model coupling