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Premature thermal decomposition behavior of 3,4-dinitrofurazanfuroxan with certain types of nitrogen-rich compounds

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Defence Technology（防务技术） 2023年第8期26卷 102-110页

作者： Jiao Huang Ru-fang peng Bo Jin State Key Laboratory of Environment-friendly Energy Materials Southwest University of Science and TechnologyMianyang621010SichuanPR China

3,4-Dinitrofurazanfuroxan(DNTF),as a high-energy-density material,features good thermal stability and wide *** study aimed to elucidate the thermal decomposition mechanism of DNTF combined with nitrogen-rich compounds containing *** thermal stabilities of DNTF and its hybrid systems were investigated using differential thermal analysis/thermogravimetry(TG),vacuum stability test,and accelerating rate calorimetry under isothermal,non-isothermal,and adiabatic conditions,*** showed that the thermal stability and thermal safety of DNTF significantly decreased after combining with nitrogen-rich compounds containing *** results showed that the activation energy of the DNTF hybrid systems was significantly lower than that of *** TGIR was used to monitor the generation of fugitive gases during the thermal decomposition of the DNTF/5-aminotetrazole(5-ATZ)***,the nitrogen-rich molecules containing N-H interacted extensively with DNTF,and this interaction accelerated the thermal degradation of DNTF.

关键词： DNTF NeH rich Nitrogen compounds Advanced thermal decomposition peak

Size-dependent peroxidase-like catalytic activity of Fe_3O_4 nanoparticles

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Chinese Chemical Letters 2008年第6期19卷 730-733页

作者： fang fang peng YU Zhang Ning Gu State Key Laboratory of Bioelectronics Southeast University Nanjing 210096 China Jiangsu Laboratory for Biomaterials and Devices Southeast University Nanjing 210096 China School of Chemistry and Chemical Engineering Southeast University Nanjing 210096 China

Peroxidase-like catalytic properties of Fe3O4 nanoparficles （NPs） with three different sizes, synthesized by chemical coprecipitation and sol-gel methods, were investigated by UV-vis spectrum analysis. By comparing Fe3O4 NPs with average diameters of 11, 20, and 150 nm, we found that the catalytic activity increases with the reduced nanoparticle size. The electrochemical method to characterize the catalytic activity of Fe3O4 NPs using the response currents of the reaction product and substrate was also developed.

关键词： Fe3O4 nanoparticles Peroxidase-like catalytic activity Electrochemistry

Analysis of the Phenomena of Diamond Synthesis by Seeding with Diamond

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Journal of Materials Science & Technology 2008年第5期24卷 809-812页

作者： Meiguang ZHANG Haiyan YAN fang peng Department of Physics Baoji University of Arts and Sciences Baoji 721007 China Department of Chemistry and Chemical Engineering Baoji University of Arts and Sciences Baoji 721007 China Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 China

Synthesizing diamond single crystal by diamond seed particles which were electroplated with nickel film as catalyst under high pressure and high temperature （HPHT） was described. The microstructure of nickel film after synthesis and morphology of grown diamond were investigated by means of X-ray diffraction （XRD） and scanning electron microscopy （SEM）, respectively. The phase structure in nickel film were graphite, NiC, Ni, and diamond structure hadn＇t been found. A lot of recrystallized graphite pits appear in interface between the inner surface of nickel film and the surface diamond. It is shown that the new-grown diamond was developed epitaxially on the crystal planes of seeds. Also, the new-grown diamond grew by two-dimensional nucleation and by a layer growth mechanism. The growth process of crystal was microaggregate→step→expansion→new crystal layers, and the flat growth interface transformed into a cellular interface at the same time.

关键词： Microstructure Nickel-plated seeds High pressure and high temperature (HPHT)

A disk I/O optimized system for concurrent graph processing jobs

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Frontiers of Computer Science 2024年第3期18卷 13-29页

作者： Xianghao XU fang WANG Hong JIANG Yongli CHENG Dan FENG peng fang School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China Department of Computer Science&Engineering University of Texas at ArlingtonArlingtonTX 76019USA College of Computer and Data Science Fuzhou UniversityFuzhou 350108China Zhejiang Lab Hangzhou 311121China

In order to analyze and process the large graphs with high cost efficiency,researchers have developed a number of out-of-core graph processing systems in recent years based on just one commodity *** the other hand,with the rapidly growing need of analyzing graphs in the real-world,graph processing systems have to efficiently handle massive concurrent graph processing(CGP)***,due to the inherent design for single graph processing job,existing out-of-core graph processing systems usually incur unnecessary data accesses and severe competition of I/O bandwidth when handling the CGP *** this paper,we propose GraphCP,a disk I/O optimized out-of-core graph processing system that efficiently supports the processing of CGP *** proposes a benefit-aware sharing execution model to share the I/O access and processing of graph data among the CGP jobs and adaptively schedule the graph data loading based on the states of vertices,which efficiently overcomes above challenges faced by existing out-of-core graph processing ***,GraphCP adopts a dependency-based future-vertex updating model so as to reduce disk I/Os in the future *** addition,GraphCP organizes the graph data with a Source-Sorted Sub-Block graph representation for better processing capacity and I/O access *** evaluation results show that GraphCP is 20.5×and 8.9×faster than two out-of-core graph processing systems GridGraph and GraphZ,and 3.5×and 1.7×faster than two state-of-art concurrent graph processing systems Seraph and GraphSO.

关键词： graph processing disk I/O concurrent jobs

SHARAD study on the structures and permittivity of a buried impact crater in Martian Central Elysium Planitia

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Science China Earth Sciences 2023年第11期66卷 2452-2462页

作者： peng fang Wenzhe FA Jinhai ZHANG Yangting LIN Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Engineering Laboratory for Deep Resources Equipment and Technology Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100029China Institute of Remote Sensing and Geographical Information System School of Earth and Space SciencesPeking UniversityBeijing 100871China

The Elysium Planitia,located in the transition zone between the northern and southern hemispheres,is one of the key areas for studying the stratigraphic structure and geological history of *** studies have shown that this plain has undergone complex surface modification processes including fluvial and volcanic processes,and systematic progress has been made in the study of macro-geological ***,there are relatively few studies on the regional structure of the plain,which restricts our understanding of the regional geological processes.A buried impact crater in the central part of the Elysium Planitia could have recorded the surface modification process since the formation of the impact crater,however,it is difficult to distinguish the subsurface stratigraphy due to the weak orbital radar reflection *** this study,we denoised Shallow Radar data and obtained a radargram with clear subsurface *** estimated the permittivity of subsurface materials via a multilayer reflection *** results show that two subsurface reflectors divide the structure of the buried impact crater into three layers(overlying layer,underlying layer,and bottom layer).The shallow subsurface reflector covers almost the whole impact crater,while the deep subsurface reflector covers only the southwest part of the impact *** the permittivity inversion results with the geological background of lava activity in the Elysium Planitia area,we argue that the overlying layer may be a mixture of regolith and lava flow with low density,while the underlying layer and bottom layer are dense lava *** reflector between the underlying layer and bottom layer is probably a thin deposit derived from weathering between two lava activities,and its possible formation mechanism is as follows:the crater rim and peripheral ejecta has undergone relatively strong wind erosion and the eroded material was transport to the southwestern part of the impact crater,forming

关键词： Mars Elysium Planitia SHARAD Buried crater Permittivity inversion

Planning an adaptive reuse development of underutilized urban underground infrastructures:A case study of Qingdao,China

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Underground Space 2024年第1期14卷 18-33页

作者： Yong-Kang Qiao fang-Le peng Yun-Hao Dong Chun-fang Lu Research Center for Underground Space&Department of Geotechnical Engineering Tongji UniversityShanghai 200092China

Urban underground infrastructures(UUIs)are a vital component of built capital for urban ***,many cities are now home to a multitude of disused or underutilized UUIs,not least aged purpose-built underground facilities,causing a waste of valuable underground space resource *** the process of urban renewal,adaptive reuse can be an attractive solution to breathe new life into underutilized UUIs,while addressing some of the modern problems of the built environment by an economically feasible ***,there is a prevalent absence in the current literature of the overarching planning and decision-making approaches for an adaptive reuse development of underutilized *** the intention of addressing this shortfall,this paper first lays out development strategies,then sets the generic patterns for adaptive reuse of disused or underutilized *** the city of Qingdao,China as a case study,detailed planning and decision-making approaches with the aid of multi-source data and spatial analysis tools are *** is anticipated that the findings of this research will assist the adaptive reuse development of UUIs in providing theoretical guidance and empirical evidence,thereby enhancing the role of urban underground space use in contributing to urban revitalization and urban sustainability.

关键词： Urban underground infrastructures Underutilized Adaptive reuse Planning Urban renewal

Monotonic tensile behavior analysis of three-dimensional needle-punched woven C/SiC composites by acoustic emission

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Journal of University of Science and Technology Beijing 2008年第3期15卷 302-306页

作者： peng fang Laifei Cheng Litong Zhang Jingjiang Nie National Key Laboratory of Thcrmostrucmre Composite Materials Northwestern Polytechnical University Xi＇an Shaanxi 710072 China

High toughness and reliable three-dimensional needled C/SiC composites were fabricated by chemical vapor infiltration （CVI）. An approach to analyze the tensile behaviors at room temperature and the damage accumulation of the composites by means of acoustic emission was researched. Also the fracture morphology was examined by S-4700 SEM after tensile tests to prove the damage mechanism. The results indicate that the cumulative energy of acoustic emission （AE） signals can be used to monitor and evaluate the damage evolution in ceramic-matrix composites. The initiation of room-temperature tensile damage in C/SiC composites occurred with the growth of micro-cracks in the matrix at the stress level about 40% of the ultimate fracture stress. The level 70% of the fracture stress could be defined as the critical damage strength.

关键词： C/SiC composites tensile behavior damage damage mechanism acoustic emission

A Unified Symmetry of Mechanical Systems with Variable Mass in Phase Space

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Communications in Theoretical Physics 2006年第3X期46卷 385-388页

作者： WANG peng fang Jian-Hui ZHANG peng-Yu, DING Ning College of Physics and Technology China University of Petroleum Dongying 257061 China

In this paper, the definition and the criterion of a unified symmetry of the mechanical system with variable mass in phase space are given. The Noether conserved quantity, the generalized Hojman conserved quantity, and Mei conserved quantity deduced from the unified symmetry are obtained. An example is given to illustrate the application of the results.

关键词： phase space variable mass system unified symmetry conserved quantity

An Evaluation Framework for Virtual Articulatory Movements Based on Medical Video

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Chinese Journal of Electronics 2019年第3期28卷 585-592页

作者： LI Rui YU Jun LI Xian fang peng WANG Zengfu Department of Automation University of Science and Technology of China Institute of Intelligent Machines Chinese Academy of Sciences

An important aspect of a Speech tutoring aimed talking-head system(STTS) is the accuracy of produced articulatory movements. Little work has been done for the Articulatory movements’ accuracy(AMA)evaluation in STTSs. Although subjective evaluation is reliable, it is time consuming and inconvenient. The traditional objective evaluation is comparing the motion of several points on the surface of the synthetic articulator to the Electromagnetic articulography(EMA) data which describes the motion of corresponding points on the articulatory surface of a speaker. The EMA information is too limited to describe the whole shape changing of deformable articulators for a speech process. To solve this problem, we propose a substantially different objective evaluation method based on a separately recorded medical video. The synthetic articulatory shapes in a speech process are compared to the corresponding shapes tracked from the medical video. This method is translation,rotation, and scaling invariant which allows the comparison of the shapes from the synthetic tongue and the medical images. The time difference problem of synthesis results and medical video is solved by introducing Dynamic time warping(DTW) to the proposed method. Experimental results demonstrate that our method has the ability to evaluate the deformation shape accuracy from an entire articulation process. The comparison results suggest that our method is more accurate than the traditional method especially for deformable articulators.

关键词： Accuracy evaluation Medical video Articulatory animation Speech tutoring aimed talkinghead system