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AocML： A Domain-Specific Language for Model-Driven Development of Activity-Oriented Context-Aware Applications

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Journal of Computer Science & Technology 2018年第5期33卷 900-917页

作者： Xuan-Song li Xian-Ping Tao wei Song Kai Dong School of Computer Science and Engineering Nanjing University of Science and Technology Nanfing 210093 China State Key Laboratory for Novel Software Technology Nanjing University Nanjing 210023 China School of Computer Science and Engineering Southeast University Nanjing 211189 China

Activity-oriented context-aware （AOCA） applications are representative in pervasive computing. These appli- cations recognize daily-life human activities, perceive the environment status related to the activities, and react to ensure the smooth performance of the activities. Existing research proposed a specific light-weight, incremental method to support the development of such applications; however it is not easy to learn and use. This paper aims to facilitate the development of such applications and improve the productivity of developers. We propose AocML, a textual domain-specific language which provides a high-level abstraction of AOCA applications. Specifically, we first show the software model of AOCA applications and the abstract syntax of AocML. Then, we introduce the concrete syntax of AocML. We also implement the tools for AocML, including the development environment as well as the generation of Java code and ontology specification. Moreover, we use a case study and evaluation to demonstrate the advantages of AocML.

关键词： pervasive computing context-awareness model-driven development domain-specific language

Theoretical studies of adsorption property on Ir_4/MgO and Ir_4/γ-Al_2O_3

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Journal of Natural Gas Chemistry 2011年第6期20卷 595-602页

作者： Xianyong Pang Duichun li Zizhang wei Jinmo Zhao Guichang Wang College of Chemistry and Chemical Engineering Taiyuan University of Technology Taiyuan 030024 Shanxi China Tianjin Enviromental Engineering Assessment Center Tianjin 300191 China Department of Chemistry and the Central of Theory and Computational Nankai University Tianjin 300071 China College of Chemistry and Chemical Engineering Shanxi Datong University Datong 037009 Shanxi China

The adsorption properties of atomic and molecular species on Ir4/MgO and Ir4/γ-Al2O3 have been systematically studied by means of planewave density functional theory（DFT）calculations using the periodic boundary *** binding energies of these species were ordered as follows：H2O〈C2H4〈H〈OH〈S〈N〈O〈*** adsorption energies of adatoms on Ir4/MgO were larger than those on Ir4/γ-Al2O3 except hydrogen atom,but were in reverse for the molecules *** addition,the difference of adsorption energies on MgO and γ-Al2O3 supports has been elucidated by analyzing the electronic properties.A detailed investigation on state density clarifies the nature of the magnitude of adsorption *** calculated results are consistent well with the available experimental and theoretical results.

关键词： Ir4/MgO Ir4/γ-Al2O3 adsorption property DFT calculation support effect

Microstructure and Texture Evolution During the Direct Extrusion and Bending–Shear Deformation of AZ31 Magnesium Alloy

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Acta Metallurgica Sinica(English Letters) 2019年第6期32卷 710-718页

作者： Xiao-Ye liu li-wei Lu Kun Sheng Tao Zhou Hunan Provincial Key Laboratory of High Efficiency and Precision Machining of Difficult-to-Cut Material Hunan University of Science and TechnologyXiangtan 411201China School of Materials Science and Engineering Central South UniversityChangsha 410083China School of Materials Science and Engineering Chongqing University of TechnologyChongqing 400054China

AZ31 alloys were extruded by direct extrusion and bending–shear deformation(DEBS).The microstructure characteristic and texture evolution of DEBSed AZ31 sheets were investigated by electron backscattered diffraction(EBSD).It is found that DEBS technique could effectively refine grains and weaken ***,we also investigate how twinning affects dynamic recrystallization during hot extrusion.{10–12}extension twins can offer nucleation sites and enough energy to trigger dynamic ***,the character of direct extrusion and bending–shear die can lead to the activation of non-basal slip system and further dramatically weaken the basal texture of the microstructure with many preactivated basal slip systems.

关键词： Magnesium alloys Extrusion Grain refinement Texture evolution

Film Cooling Performance of a Row of Dual-fanned Holes at Various Injection Angles

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Journal of Thermal Science 2017年第5期26卷 453-458页

作者： li Guangchao WANG Haofeng ZhanG wei KOU Zhihai XU Rangshu Faculty of Aerospace Engineering Shenyang Aerospace University Shenyang China 110136

Film cooling performance about a row of dual-fanned holes with injection angles of 30°, 60 ° and 90° were experimentally investigated at blowing ratios of 1.0 and 2.0. Dual-fanned hole is a novel shaped hole which has both inlet expansion and outlet expansion. A transient thermochromic liquid crystal technique was used to reveal the local values of film cooling effectiveness and heat transfer coefficient. The results show that injection angles have strong influence on the two dimensional distributions of film cooling effectiveness and heat transfer coefficient. For the small injection angle of 30 degree and small blowing ratio of 1.0, there is only a narrow spanwise region covered with film. The increase of injection angle and blowing ratio both leads to the enhanced spanwise film diffusion, but reduced local cooling ability far away from the hole. Injection angles have comprehensive influence on the averaged film cooling effectiveness for various x/d locations. As injection angles are 30 and 60 degree, two bands of high heat transfer coefficients are found in mixing region of the gas and coolant. As injection angle increases to 90 degree, the mixing leads to the enhanced heat transfer region near the film hole. The averaged heat transfer coefficient increases with the increase of injection angle.

关键词： gas turbine film cooling dual-fanned hole thermochromic liquid crystal technique

Bio-Inspired Controller for a Robot Cheetah with a Neural Mechanism Controlling Leg Muscles

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Journal of Bionic Engineering 2012年第3期9卷 282-293页

作者： Xin Wang Mantian li Pengfei Wang wei Guo lining Sun State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001P.R.China

The realization of a high-speed running robot is one of the most challenging problems in developing legged robots. The excellent performance of cheetahs provides inspiration for the control and mechanical design of such robots. This paper presents a three-dimensional model of a cheetah that predicts the locomotory behaviors of a running cheetah. Applying biological knowledge of the neural mechanism, we control the muscle flexion and extension during the stance phase, and control the positions of the joints in the flight phase via a PD controller to minimize complexity. The proposed control strategy is shown to achieve similar locomotion of a real cheetah. The simulation realizes good biological properties, such as the leg retraction, ground reaction force, and spring-like leg behavior. The stable bounding results show the promise of the controller in high-speed locomotion. The model can reach 2.7 m-s^-1 as the highest speed, and can accelerate from 0 to 1.5 m-s^-1 in one stride cycle. A mechanical structure based on this simulation is designed to demonstrate the control approach, and the most recently developed hindlimb controlled by the proposed controller is presented in swinging-leg experiments and jump-force experiments.

关键词： biomimetics biologically-inspired robots legged robots neural mechanism artificial pneumatic muscle

Inhibition effect of phosphate on the crystal grain growth of nanosized titania

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Rare Metals 2009年第4期28卷 385-390页

作者： FENG Xiaohui liU Jingze li Ping ZhanG Yanfeng wei Yu College of Chemistry and Material Science Hebei Normal University Shijiazhuang 050016 China College of life Science Hebei Normal University Shijiazhuang 050016 China

The inhibitory effect of phosphate on the crystal grain growth of nanosized titania during high temperature calcination was investigated. Nanosized titanium dioxide powders prepared by hydrolysis of titanium tetrachloride were soaked in phosphate solutions with different concentrations. The obtained powders calcined at various temperatures were characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR）, and X-ray photoelectronic spectroscopy （XPS）. The grain size of the samples without phosphate treatment increased quickly when calcined at high temperatures, while the grain size of the samples with phosphate modification increased slowly when calcined at the same temperature. This phenomenon implies that phosphate treatment plays an important role in inhibiting the crystal grain growth of titania. The possible mechanism of the inhibition effect of phosphate on titania is discussed.

关键词： physical chemistry crystal size soaking method nanosized TiO2 phosphate

On the oxidation states of metal elements in MO-3(M=V,Nb,Ta,Db,Pr,Gd,Pa)anions

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Science China Chemistry 2016年第4期59卷 442-451页

作者： Jing Su Shuxian Hu wei Huang Mingfei Zhou Jun li Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education Department of ChemistryTsinghua UniversityBeijing 100084China Collaborative Innovation Center of Chemistry for Energy Materials Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials Department of ChemistryFudan UniversityShanghai 200433China

Relativistic quantum chemistry investigations are carried out to tackle the puzzling oxidation state problem in a series of MO3 trioxide anions of all d- and f-block elements with five valence electrons. We have shown here that while the oxidation states of V, Nb, Ta, Db, Pa are, as usual, all ＋V with divalent oxygen O（-II） in MO3- anions, the lanthanide elements Pr and Gd cannot adopt such high ＋V oxidation state in similar trioxide anions. Instead, lanthanide element Gd retains its usual ＋III oxi- dation state, while Pr retains a ＋IV oxidation state, thus forcing oxygen into a non-innocent ligand with an uncommon mono- valent radical （O＇） of oxidation state -I. A unique Pr＂- ＂（0）3 biradical with highly delocalized unpairing electron density on Pr（IV） and three O atoms is found to be responsible for stabilizing the monovalent-oxygen species in PRO3- ion, while GdO3 ion is in fact an OGd＋（O22-） complex with Gd（III）. These results show that a naive assignment of oxidation state of a chemical element without electronic structure analysis can lead to erroneous conclusions.

关键词： oxidation state non-innocent ligand biradical lanthanide trioxide anion

Modification of NiCoCrAlY with Pt: Part Ⅰ. Effect of Pt depositing location and cyclic oxidation performance

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Journal of Materials Science & Technology 2019年第3期35卷 341-349页

作者： Yingfei Yang Hongrui Yao Zebin Bao Pan Ren wei li Institute of Advanced Wear & Corrosion Resistant and Functional Material Jinan University Corrosion and Protection Division Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences

Pt layers of 5 μm in thickness were electroplated before or after depositing NiCoCrAlY coating by arc ion plating(AIP) aiming for identifying the effect of Pt enriching position on microstructure and cyclic oxidation behavior of Pt modified NiCoCrAlY coatings. Al-rich zones formed at the same position of Ptrich zones for both modified coatings due to uphill diffusion of Al driven by Pt. Cyclic oxidation tests at 1000 and 1100?C indicated that oxidation resistance of NiCoCrAlY was improved by Pt modification via different mechanisms: at surface, Pt-rich zone promoted selective oxidation of Al to form α-Al_2O_3,whilst at coating/substrate interface Pt-rich zone acted as effective diffusion barrier for titanium. Roles of Pt played in enhancing the oxidation performance of various Pt-modified NiCoCrAlY coating were investigated.

关键词： Cyclic oxidation Pt-modification NiCoCrAlY Electron probe micro-analysis(EPMA)

Fabrication of rod-shaped β-FeOOH: the roles of polyethylene glycol and chlorine anion

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Science China Chemistry 2016年第7期59卷 895-902页

作者： Xuejiao wei Xiaoling Mou Yan Zhou Yong li Wenjie Shen State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences

β-FeOOH nanorods of 40 nm wide and 450 nm long were fabricated through precisely regulating the hydrolysis kinetics of Fe3＋ in polyethylene glycol and the concentration of C1- as the structure-directing agent. Detailed structural and chemical analyses of the intermediates during the synthesis identified that the strong interaction between PEG and Fe3＋ modulated the hydrolysis kinetics of Fe3＋and prevented the aggregation of β-FeOOH nanorods; while C1- provided sufficient nucleation sites, stabilized the hollow channel of β-FeOOH, and more importantly induced the growth of the nanorods along [001] direction.

关键词： β-FeOOH nanorods hydrolysis kinetics capping agent anisotropic growth