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China Foundry 2018年第5期15卷 327-332页

作者： Chen Zhang Yu fu Han wang hai Hao Key Laboratort of Solidification Control and Digital Preparation Technology of Liaoning Province School of Materials Science and EngineeringDalian University of TechnologyDalian 116024China

Multi-objective optimization has been increasingly applied in engineering where optimal decisions need to be made in the presence of trade-offs between two or more objectives. Minimizing the volume of shrinkage porosity, while reducing the secondary dendritic arm spacing of a wheel casting during low-pressure die casting(LPDC) process, was taken as an example of such problem. A commercial simulation software Pro CASTTM was applied to simulate the filling and solidification processes. Additionally, a program for integrating the optimization algorithm with numerical simulation was developed based on SiPESC. By setting pouring temperature and filling pressure as design variables, shrinkage porosity and secondary dendritic arm spacing as objective variables, the multi-objective optimization of minimum volume of shrinkage porosity and secondary dendritic arm spacing was achieved. The optimal combination of AZ91 D wheel casting was: pouring temperature 689 °C and filling pressure 6.5 kPa. The predicted values decreased from 4.1% to 2.1% for shrinkage porosity, and 88.5 μm to 81.2 μm for the secondary dendritic arm spacing. The optimal results proved the feasibility of the developed program in multi-objective optimization.

关键词： magnesium alloy multi-objective optimization process parameters shrinkage porosity secondary dendritic arm spacing

Robust and Passive Motion Detection with COTS WiFi Devices

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Tsinghua Science and Technology 2017年第4期22卷 345-359页

作者： hai Zhu fu Xiao Lijuan Sun Xiaohui Xie Panlong Yang Ruchuan wang the College of Computer Nanjing University of Posts and Telecommunications the Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Key Lab of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education and College of Computer Nanjing University of Posts and Telecommunications the College of Computer Science and Technology University of Science and Technology of China

Device-free Passive（DfP） detection has received increasing attention for its ability to support various pervasive applications. Instead of relying on variable Received Signal Strength（RSS）, most recent studies rely on finer-grained Channel State Information（CSI）. However, existing methods have some limitations, in that they are effective only in the Line-Of-Sight（LOS） or for more than one moving individual. In this paper, we analyze the human motion effect on CSI and propose a novel scheme for Robust Passive Motion Detection（R-PMD）. Since traditional low-pass filtering has a number of limitations with respect to data denoising, we adopt a novel Principal Component Analysis（PCA）-based filtering technique to capture the representative signals of human motion and extract the variance profile as the sensitive metric for human detection. In addition, existing schemes simply aggregate CSI values over all the antennas in MIMO systems. Instead, we investigate the sensing quality of each antenna and aggregate the best combination of antennas to achieve more accurate and robust detection. The R-PMD prototype uses off-the-shelf WiFi devices and the experimental results demonstrate that R-PMD achieves an average detection rate of 96.33% with a false alarm rate of 3.67%.

关键词： device-free passive detection Received Signal Strength(RSS) channel state information MIMO

Characterizing microstructure and texture after recrystallization annealing of Hi-B steel with simutaneous decarburization and nitriding

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Journal of Iron and Steel Research International 2017年第12期24卷 1215-1222页

作者： Li Xiang Zhe Rong Bing fu hai-jun wang Sheng-tao Qiu National Engineering Research Center of Continuous Casting Technology China Iron and Steel Research Institute Group School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

How to manufacture the high magnetic induction grain-oriented silicon steel（Hi-B steel）by the process featured with the primary recrystallization annealing was demonstrated,during which nitriding and decarburizing were simultaneously realized in *** the techniques of optical microscope,scanning electronic microscope and electron backscattered diffraction,both the microstructure and the texture in the samples were *** samples had been subjected to nitriding to different nitrogen contents at two specified temperatures using the two defined microstructural parameters：the grain size inhomogeneity factorσ＊and the texture factor *** former is the ratio of the mean value to standard deviation of grain sizes;the latter is the ratio of the total volume fraction of the harmful textures to that of beneficial textures including {110}〈001〉.When the N content increased from 0.0055%to 0.0330%after the annealing at both 835 and 875°C,the resultant recrystallized grain size decreased butσ＊changed little;whilst the rise of annealing temperature from 835 to 875°C resulted in the increase in both grain size andσ＊.Moreover,either the injected N content or temperature had insignificant influence on the components of primary recrystallization texture developed during ***,the increase of temperature led to the decreases in both intensity and volume fraction of{001}〈120〉and{110}〈001〉textures but increases in the{114}〈481〉andγfiber textures and the resultant decrease of AR.

关键词： Hi-B steel Simultaneous nitriding and decarburizing annealing Primary recrystallization Microstructure Texture

Effect of Nitrogen Content on Primary Recrystallization Behavior and Magnetic Property of Hi-B Steel

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Journal of Iron and Steel Research International 2016年第10期23卷 1080-1085页

作者： hai-jun wang Bing fu Li XIANG Zhe RONG Sheng-tao QIU National Engineering Research Center of Continuous Casting Technology Central Iron and Steel Research Institute School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

The effect of nitrogen content on primary recrystallization microstructure,texture and magnetic property of Hi-B steel was studied by means of optical microscopy（OM）,scanning electron microscopy（SEM）,and electron backscatter diffraction（EBSD）.When nitrogen content increased gradually from 0.005 5% to 0.031 0%,the primary grain size and variation coefficient of nitrided sheet reduced from 26.85μm,0.590 to 18.87μm,0.525-0.565,***,the primary recrystallization texture style of nitrided sheet was nearly identical to the texture style of decarburized sheet before nitriding treatment,but exhibiting a certain change on texture *** variation of average magnetic induction value（B8）and core loss value（P17/50）were manifested to be Mshaped and W-shaped curves,*** nitrogen content reached 0.016 0%,the best value of the average magnetic property of the final product was obtained as follows：the B8 and P17/50 were 1.921 Tand 0.968W/kg,***,the best performance,B8 and P17/50,of single sheet was 1.964 Tand 0.854 W/kg.

关键词： nitriding decarburization primary recrystallization magnelic property texture Hi-B steel

CoWO4 nanopaticles wrapped by RGO as high capacity anode material for lithium ion batteries

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Rare Metals 2017年第5期36卷 411-417页

作者： Peng Yu Lei wang Xu Liu Hong-Gang fu hai-Tao Yu Key Laboratory of functional Inorganic Material Chemistry Ministry of Education of China Heilongjiang UniversityHarbin 150080China

Transition-metal oxides have attracted increased attention in the application of high-performance lithium ion batteries（LIBs）, owing to its higher reversible capacity,better structural stability and high electronic ***, CoWO4 nanoparticles wrapped by reduced graphene oxide（CoWO4–RGO） were synthesized via a facile hydrothermal route followed by a subsequent heat-treatment process. When evaluated as the anode of LIB, the synthetic CoWO4–RGO nanocomposite exhibits better Li^＋ storage properties than pure CoWO4 nanostructures synthesized without graphene oxide（GO）. Specifically, it delivers a high initial specific discharge capacity of1100 mAh·g^-1 at a current density of 100 mA·g^-1, and a good reversible performance of 567 mAh·g^-1 remains after the 100th cycle. Moreover, full battery using CoWO4–RGO as anode and commercial LiCoO2 powder as cathode was assembled, which can be sufficient to turn on a 3 V,10 mW blue light emitting diode（LED）. The enhanced electrochemical performance for lithium storage can be attributed to the three-dimensional（3D） structure of the CoWO4–RGO nanocomposite, which can accommodate huge volume changes, and synergetic effect between CoWO4 and reduced graphite oxide（RGO） nanosheets,including an increased conductivity, shortened Li^＋ diffusion path.

关键词： CoWO4 Transition-metal oxide Graphene Li-ion battery Anode

Natural recovery of different areas of a deserted quarry in South China

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Journal of Environmental Sciences 2008年第4期20卷 476-481页

作者： DUAN Wenjun REN hai fu Shenglei wang Jun YANG Long ZHANG Jinping Heshan National Field Research Station of Forest Ecosystem South China Botanical Garden the Chinese Academy of Sciences Guangzhou 510650 China Graduate University of the Chinese Academy of Sciences Beijing 100039 China

A quarry is a surface mining operated place, which produces enormous quantifies of gravel, limestone, and other materials for industrial and construction applications. Restoration and revegetation of deserted quarries are becoming increasingly important. Three areas of a typical quarry in South China： terrace for crushed materials （terrace）, spoiled mound, and remaining side slope, were investigated, to compare the existing plant species and to study the relationship between environmental factors and revegetation. The plant species composition of these three areas was found to differ significantly after eight years of natural recovery. The typical plant communities found over them were composed of gramineous herbs, ferns, and shrubs. Soil organic matter, soil moisture, and soil bulk density were considered to be the major determining factors for vegetation succession. There existed abiotic and biotic thresholds during quarrying restoration. Suggestions had been presented that could have accelerated the process of natural recovery in quarries.

关键词： natural recovery quarry vegetation environment-vegetation relationships

Quantitative analysis of 3D vasculature for evaluation of angiogenesis in liver fibrosis with SR-μCT

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Nuclear Science and Techniques 2016年第5期27卷 255-263页

作者： hai Tan Yi fu Da-Dong wang Xi Zhang Ti-Qiao Xiao Shanghai Institute of Applied Physics Chinese Academy of Sciences Jiading Campus University of Chinese Academy of Sciences Department of Radiology Cancer Hospital Fudan University Department of Oncology Shanghai Medical College Fudan University Quantitative Imaging

The micro-CT imaging of vasculature is a powerful tool for evaluation of angiogenesis,a prominent characteristic of hepatic *** segment or bifurcation density,which is usually adopted to evaluate the degree of hepatic fibrosis,does not always work and may lead to incorrect assessment,especially when the threedimensional vasculature obtained is imperfect in sample preparation or image *** this paper,we propose a new parameter to solve this *** experimental results demonstrate that the method is robust and reliable,and is practical for angiogenesis evaluation,despite of image data *** quantitative analysis method can be extended to investigate other kinds of diseases in which vasculature change is a key indicator.

关键词：血管生成肝纤维化 CT成像评价三维定量分析方法图像采集样品制备

Interfacial Engineering of Polymer Blend with Janus Particle as Compatibilizer

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Chinese Journal of Polymer Science 2023年第4期41卷 500-515,I0005页

作者： hai-Ling He fu-Xin Liang Institute of Polymer Science and Engineering Department of Chemical EngineeringTsinghua UniversityBeijing100084China

Mixing two or more polymers to produce the“polymer alloy”is one of the most versatile and economical strategies for developing new polymeric *** compatibility between polymer components largely determines the comprehensive performance of polymer *** recently,a type of unique surface partitioned materials,Janus particles,has been proposed to act as a novel interfacial compatibilizer for polymer *** Janus particles integrates the amphipathicity of diblock copolymer and interfacial stabilization of nanoparticles,displaying a significant superiority in comparison with molecular compatibilizers for a wide range of polymer *** this review,we mainly focus on the compatibilizing effects of Janus nanofillers of various morphologies,including spherical,snowman-like,and two-dimensional nanosheets,on polymer *** shed light on the impacts of compatibilization of Janus particles on phase morphologies,mechanical properties,and functionalities of polymer *** review could provide a guidance for designing an effective Janus particle compatibilizer to develop high-performance polymer blends.

关键词： Janus particles Compatibilizer Polymer blend Interfacial engineering

Lightweight hybrid visual-inertial odometry with closed-form zero velocity update

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Chinese Journal of Aeronautics 2020年第12期33卷 3344-3359页

作者： QIU Xiaochen ZHANG hai fu Wenxing School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Science and Technology on Aircraft Control Laboratory Beijing 100191China Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing 100074China

Visual-Inertial Odometry(VIO) fuses measurements from camera and Inertial Measurement Unit(IMU) to achieve accumulative performance that is better than using individual *** VIO is an extended Kalman filter-based solution which augments features with long tracking length into the state vector of Multi-State Constraint Kalman Filter(MSCKF). In this paper, a novel hybrid VIO is proposed, which focuses on utilizing low-cost sensors while also considering both the computational efficiency and positioning precision. The proposed algorithm introduces several novel contributions. Firstly, by deducing an analytical error transition equation, onedimensional inverse depth parametrization is utilized to parametrize the augmented feature *** modification is shown to significantly improve the computational efficiency and numerical robustness, as a result achieving higher precision. Secondly, for better handling of the static scene,a novel closed-form Zero velocity UPda Te(ZUPT) method is proposed. ZUPT is modeled as a measurement update for the filter rather than forbidding propagation roughly, which has the advantage of correcting the overall state through correlation in the filter covariance matrix. furthermore, online spatial and temporal calibration is also incorporated. Experiments are conducted on both public dataset and real data. The results demonstrate the effectiveness of the proposed solution by showing that its performance is better than the baseline and the state-of-the-art algorithms in terms of both efficiency and precision. A related software is open-sourced to benefit the community.

关键词： Inverse depth parametrization Kalman filter Online calibration Visual-inertial odometry Zero velocity update

不同类型学业压力对不同年级高中生执行功能子成分的影响

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心理学报 2025年第1期57卷 18-35页

作者：马超汪彦云付军军赵鑫甘肃省行为与心理健康重点实验室西北师范大学心理学院兰州730070

选取985名高一~高三年级的学生,采用相关分析和结构方程模型等方法考察了学业压力4个子维度在不同年级高中生各执行功能成分中的作用。结果发现,随着高中生年级的升高,父母压力和教师压力对各执行功能成分的负向预测作用逐渐增强,社交... 详细信息

选取985名高一~高三年级的学生,采用相关分析和结构方程模型等方法考察了学业压力4个子维度在不同年级高中生各执行功能成分中的作用。结果发现,随着高中生年级的升高,父母压力和教师压力对各执行功能成分的负向预测作用逐渐增强,社交压力对各执行功能成分的负向预测作用逐渐减弱。相比之下,自我压力对高中生的干扰抑制、反应抑制和注意转换能力均显示出了正向预测作用,并随年级的升高而增强。这表明,不同类型学业压力对各执行功能成分的预测作用存在差异,并将随高中生年级的升高而发生变化。本研究所产生的结论对于教育工作者有效制定高中生学业压力应对策略具有重要的启示意义。

关键词：执行功能学业压力高中生结构方程模型

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