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Ionic liquid choline chloride-urea dissolving cattle bone extracted hydroxyapatite

Journal of Bionanoscience 2018年第3期12卷 437-441页

作者： Song, Wei Yang, Yan Deng, Yu Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China Department of Osteo-Internal Medicine Tianjin Hospital Tianjin300211 China School of Materials Science and Chemical Engineering Tianjin University of Science and Technology Tianjin300457 China

The dissolving technique of ionic liquid (IL) was applied in extraction process of hydroxyapatite (HAp). Product HAp was extracted by IL choline chloride-urea (ChCl-Urea) dissolving cattle bone. The optimum conditions for regeneration process of cattle bone were determined by single factor, orthogonal and verification experiments. IR spectra of regenerated bone, undissolved bone and raw bone showed that the main groups of regenerated bone did not change. It was indicated that ionic liquid did not damage the bone collagen of raw bone, and the collagen was only dissolved by IL. IR spectrum of the product HAp revealed that its components were similar to those of the natural bone. SEM pattern showed that the crystal shape of the product HAp appeared rod-like shape mostly, and the crystal structure was relatively complete. XRD diffraction explained that there was no difference between product HAp and standard HAp for the crystalline form and compositions. Copyright © 2018 American Scientific Publishers All rights reserved.

关键词： Hydroxyapatite

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Processing of a comprehensive windowed multipole library via vector fitting

Processing of a comprehensive windowed multipole library via...

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2018 International Conference on Physics of reactors: reactor Physics Paving the Way Towards More Efficient systems, PHYSOR 2018

作者： Liang, Jingang Peng, Xingjie Liu, Shichang Josey, Colin Forget, Benoit Smith, Kord Department of Nuclear Science and Engineering Massachusetts Institute of Technology CambridgeMA02139 United States Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China ChengduSichuan610000 China Department of Engineering Physics Tsinghua University Beijing100084 China

ISBN: (纸本)9781713808510

The windowed multipole method is a promising technique to efficiently perform Doppler broadening of nuclear cross section data and has so far been based on the conversion of resolved resonance parameters to the pole representation. However, 40% of ENDF/B-VII. 1 nuclides cannot be directly converted in windowed multipole format because some nuclides are provided directly as point-wise data in the evaluation or the presence of non-smooth point-wise data that prevents the transformation. A new approach based on Vector Fitting technique was recently investigated to convert point-wise cross section data to poles and residues. This paper presents a generalized Vector Fitting algorithm which is able to generate optimized multipole parameters from ENDF point-wise data and applicable to a wide range of nuclides. Using this algorithm, a comprehensive windowed multipole library which contains all ENDF/B-VII.l nuclides was produced for the first time. Accuracy of the library was demonstrated by microscopic cross section comparisons at different temperatures, and calculation results of the BEAVRS benchmark were performed to demonstrate its applicability to realistic problems. © 2018 International Conference on Physics of reactors, PHYSOR 2018: reactor Physics Paving the Way Towards More Efficient systems. All rights reserved.

关键词： Doppler effect

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Learning Local Feature Descriptor with Motion Attribute For Vision-based Localization

Learning Local Feature Descriptor with Motion Attribute For ...

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2019 IEEE/RSJ International Conference on Intelligent Robots and systems (IROS)

作者： Yafei Song Di Zhu Jia Li Yonghong Tian Mingyang Li AI Labs Alibaba Group Hangzhou China National Key Laboratory of Virtual Reality Technology and System School of Computer Science and Engineering Beihang University Beijing China National Engineering Laboratory for Video Technology School of Electronics Engineering and Computer Science Peking University Beijing China

In recent years, camera-based localization has been widely used for robotic applications, and most proposed algorithms rely on local features extracted from recorded images. For better performance, the features used for open-loop localization are required to be short-term globally static, and the ones used for re-localization or loop closure detection need to be long-term static. Therefore, the motion attribute of a local feature point could be exploited to improve localization performance, e.g., the feature points extracted from moving persons or vehicles can be excluded from these systems due to their unsteadiness. In this paper, we design a fully convolutional network (FCN), named MD-Net, to perform motion attribute estimation and feature description simultaneously. MD-Net has a shared backbone network to extract features from the input image and two network branches to complete each sub-task. With MD-Net, we can obtain the motion attribute while avoiding increasing much more computation. Experimental results demonstrate that the proposed method can learn distinct local feature descriptor along with motion attribute only using an FCN, by outperforming competing methods by a wide margin. We also show that the proposed algorithm can be integrated into a vision-based localization algorithm to improve estimation accuracy significantly.

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Surrogate-based optimization method applied to multidisciplinary design optimziation architectures 31

Surrogate-based optimization method applied to multidiscipli...

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31st Congress of the International Council of the Aeronautical sciences, ICAS 2018

作者： Xu, Chen-Zhou Han, Zhong-Hua Zhang, Ke-Shi Song, Wen-Ping Aerodynamic and Multidisciplinary Design Optimization Group National Key Laboratory of Science and Technology on Aerodynamic Design and Research Northwestern Polytechnical University Xi'an710072 China

ISBN: (纸本)9783932182884

During the past three decades, various multidisciplinary design optimization (MDO) architectures have been developed, using different ways of dealing with interactions between disciplines, which can be solved by optimization algorithms. In the field of aircraft design optimization, as the complexity of system increases, conventional optimization algorithms applied in MDO architecture exhibit many drawbacks, such as low efficiency, poor robustness or easily getting trapped in a local extra. In this paper, a newly developed surrogate-based optimization (SBO) method is applied to replace traditional optimization algorithms in the MDO architectures so that the efficiency of solving MDO problems can be dramatically improved. To demonstrate its effectiveness, a benchmark MDO test case and Speed Reducer MDO case are employed. It shows that the efficiency of SBO is two-order higher than that of genetic algorithm and the optimization results are better than that obtained by gradient-based algorithm. Besides, SBO is applied to the aerodynamic/structural integrated design of a transport wing in MDF architecture. The weight of the wing is reduced by 30.32% while its aerodynamic performance is retained at a cruise condition. © 31st Congress of the International Council of the Aeronautical sciences, ICAS 2018. All rights reserved.

关键词： Efficiency

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Optimum design of High Frequency Transformer Based on Winding Spacing

Optimum Design of High Frequency Transformer Based on Windin...

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International Conference on Electrical Machines and systems (ICEMS)

作者： Zhiran Peng Guangsen Wang Xiaofei Zhai Xiao Zhang Hao Zhou Chenglin Yi National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan China Daqo kaifan electric co. Nanjing China

ISBN: (纸本)9781728133997

When designing a series resonant converter, a resonant inductor is usually connected on series in the circuit which leads to an increase in the weight of the device. If the leakage inductance of the transformer is used as a resonant inductor, the weight will be reduced, but the high-frequency leakage flux will bring higher losses. In order to solve this problem, this paper deduces the analytical expression of leakage inductance with respect to winding spacing by magnetic field partitioning method, and constructs a mathematical model about the weight of series resonant inductor. The minimum weight is set as the optimization target, the transformer efficiency as constraints. The Fmincon function in matlab is used to obtain the optimal value of the winding spacing. A three-winding transformer prototype with rated working frequency of 15 kHz and rated power of 25 kW was designed and wounded through this method. The experimental results of the transformer were consistent with the theoretical calculations. The optimization method in this paper can provide reference for the design of high frequency transformers for series resonant converters.

关键词： Windings Inductance Magnetic cores Inductors Oil insulation Power transformer insulation RLC circuits

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Mapping essential urban land use categories in china(EULUC-china):preliminary results for 2018

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science Bulletin 2020年第3期65卷 182-187页

作者： Peng Gong Bin Chen Xuecao Li Han Liu Jie Wang Yuqi Bai Jingming Chen Xi Chen Lei Fang Shuailong Feng Yongjiu Feng Yali Gong Hao Gu Huabing Huang Xiaochun Huang Hongzan Jiao Yingdong Kang Guangbin Lei Ainong Li Xiaoting Li Xun Li Yuechen Li Zhilin Li Zhongde Li Chong Liu Chunxia Liu Maochou Liu Shuguang Liu Wanliu Mao Changhong Miao Hao Ni Qisheng Pan Shuhua Qi Zhehao Ren Zhuoran Shan Shaoqing Shen Minjun Shi Yimeng Song Mo Su Hoi Ping Suen Bo Sun Fangdi Sun Jian Sun Lin Sun Wenyao Sun Tian Tian Xiaohua Tong Yihsing Tseng Ying Tu Hong Wang Lan Wang Xi Wan Zongming Wang Tinghai Wu Yaowen Xie Jian Yang Jun Yang Man Yuan Wenze Yue Hongda Zeng Kuo Zhang Neng Zhang Tao Zhang Yu Zhang Feng Zhao Yichen Zheng Qiming Zhou Nicholas Clinton Zhiliang Zhu Bing Xu Ministry of Education Key Laboratory for Earth System Modeling Department of Earth System ScienceTsinghua UniversityBeijing 100084China Tsinghua Urban Institute Tsinghua UniversityBeijing 100084China Center for Healthy Cities Institute for China Sustainable UrbanizationTsinghua UniversityBeijing 100084China Department of Land Air and Water ResourcesUniversity of CaliforniaDavisCA 95616-8627USA Department of Geological and Atmospheric Sciences Iowa State UniversityAmesIA 50011USA State Key Laboratory of Remote Sensing Science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijing 100101China AI for Earth Laboratory Cross-Strait InstituteTsinghua UniversityBeijing 100084China International Institute for Earth System Sciences Nanjing UniversityNanjing 210093China Research Center for Ecology and Environment of Central Asia Chinese Academy of SciencesUrumchi 830011China Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China National Engineering Laboratory for Applied Technology in Forestry&Ecology in South China College of Life Science and TechnologyCentral South University of Forestry and TechnologyChangsha 410004China College of Surveying&Geo-Informatics Tongji UniversityShanghai 200092China Department of Urban Planning College of Architecture and Urban PlanningTongji UniversityShanghai 200092China Beijing Institute of Urban Planning Beijing 100045China Department of Urban Planning School of Urban DesignWuhan UniversityWuhan 430072China College of Earth Sciences Jilin UniversityChangchun 130061China Research Center for Digital Mountain and Remote Sensing Application Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China Institute of Remote Sensing and Geographic Information System School of Earth and Space SciencesPeking UniversityBeijing 100871China Department of Urban and Regional Planning School of Geography and PlanningSun Yat-sen Univ

Land use reflects human activities on *** land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and *** areas have widespread effects on local hydrology,climate,biodiversity,and food production[1,2].However,maps,that contain knowledge on the distribution,pattern and composition of various land use types in urban areas,are limited to city *** mapping standard on data sources,methods,land use classification schemes varies from city to city,due to differences in financial input and skills of mapping *** address various national and global environmental challenges caused by urbanization,it is important to have urban land uses at the national and global scales that are derived from the same or consistent data sources with the same or compatible classification systems and mapping *** is because,only with urban land use maps produced with similar criteria,consistent environmental policies can be made,and action efforts can be compared and assessed for large scale environmental ***,despite of the fact that a number of urban-extent maps exist at global scales[3,4],more detailed urban land use maps do not exist at the same *** at big country or regional levels such as for the United States,china and European Union,consistent land use mapping efforts are rare[5,6](e.g.,https://***/open_land_use/).

关键词： EULUC-china 土地利用类型

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Deployable antenna mechanism with class of modular truss based on tetrahedral combination unit

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Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica 2020年第3期41卷 423219页

作者： Guo, Jinwei Huang, Zhirong Xu, Yundou Guo, Luyao Yao, Jiantao Zhao, Yongsheng Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Qinhuangdao066004 China Xi'an710100 China Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of National Education Yanshan University Qinhuangdao066004 China

To solve the complex structure, the low folding rate, and the large number of motion pairs of the existing tetrahedral-based truss antenna mechanism, a class of new modular deployable structure is proposed based on the 3RR-3RRR tetrahedral combination unit and the 3RR-3URU tetrahedral symmetric combination unit. The modular structure consisting of three combination units is selected as the analysis object. First, the composition of the modular structure and the axis arrangement of the Hook hinges are introduced in detail, and the number and property of the Degree of Freedom (DOF) of the combination unit itself are obtained by applying the idea of link-demolishing-equivalent-restoration, the screw theory and the G-K formula. Second, the motion simulation of the two modular structures is carried out by using Adams dynamics simulation software. The simulation results verified the correctness of the DOF analysis. The folding rate of the mechanism is characterized by the ratio of the space volume occupied by the mechanism when fully unfolding and fully folding. The folding rates of the existing non-modular mechanisms and modular mechanisms based on tetrahedral unit are calculated. Finally, the number of DOF and motion pairs, the folding rate of non-modular mechanisms and modular mechanisms are compared and analyzed. The analysis results show that the modular structure based on the 3RR-3URU tetrahedral symmetrical combination unit can achieve a large folding rate, and the number of degree of freedom and motion pairs are also relatively reduced. In addition, fewer types of links are use when forming large antennas. The research results provide a theoretical basis for the design and analysis of such modular truss deployable antenna structures. © 2020, Press of Chinese Journal of Aeronautics. All right reserved.

关键词： Trusses

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Ratcheting Behavior of SA508-3 Steel at Elevated Temperature:Experimental Observation and Simulation

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Acta Metallurgica Sinica(English Letters) 2017年第9期30卷 822-828页

作者： Jun Tian Yu Yang Li-Ping Zhang Xue-Jiao Shao Juan Du Qian-Hua Kan Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and EngineeringSouthwest Jiaotong University

A series of monotonic uniaxial tensile tests, strain-controlled and stress-controlled cyclic tests of SA508-3 steel were conducted from 25 to 350℃. Results showed that the steel exhibited temperature-dependent cyclic softening characteristic and obvious ratcheting behavior, and dynamic strain aging was observed in the range of 250-350℃. Based on experimental observations, a temperature-dependent cyclic plastic constitutive model was proposed by introducing the nonlinear cyclic softening and kinematic hardening rules, and the dynamic strain aging was also considered into the constitutive model. Comparisons between experiments and simulations were carded out to validate the proposed model at elevated temperature.

关键词： Ratcheting Constitutive model Dynamic strain aging Cyclic loading Elevated temperature

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Real-time imaging of accelerated solid-liquid-gas reactions with nanobubbles

Research Square

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Research Square 2020年

作者： Wang, Wen Xu, Tao Chen, Jige Shangguan, Junyi Dong, Hui Ma, Huishu Zhang, Qiubo Bai, Tingting Guo, Zhirui Fang, Haiping Zheng, Haimei Sun, Litao SEU-FEI Nano-Pico Center Key Laboratory of MEMS of Ministry of Education Collaborative Innovation Center for Micro/Nano Fabrication Device and System Southeast University Nanjing210096 China Materials Sciences Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Shanghai Synchrotron Radiation Facility Zhangjiang Laboratory Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai201204 China Department of Physics East China University of Science and Technology Shanghai200237 China Department of Materials Science and Engineering University of California BerkeleyCA94720 United States Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai201800 China Key Laboratory of Welding Robot and Application Technology of Hunan Province Engineering Research Center of Complex Tracks Processing Technology Equipment of Ministry of Education Xiangtan University Xiangtan411105 China The Second Affiliated Hospital Key Laboratory for Aging & Disease Nanjing Medical University Nanjing210011 China

Solid-liquid-gas reactions are ubiquitous. An understanding of how gases influence the reactions at the nanoscale is significant for achieving the enhanced triple-phase reactions. Here, we report a real-time observation of the accelerated etching of gold nanorods with oxygen nanobubbles in aqueous hydrobromic acid using liquid cell transmission electron microscopy (TEM). Our observation reveals that when an oxygen nanobubble is close to a nanorod below the critical distance (~1nm), the local etching rate is significantly enhanced with over an order of magnitude faster. Molecular dynamics simulations results show that the strong attractive van der Waals interaction between the gold nanorod and oxygen molecules facilitates the transport of oxygen through the thin liquid layer to the gold surface and thus plays a crucial role in increasing the etching rate. This result sheds light on the rational design of solid-liquid-gas reactions for enhanced activities. © 2020, CC BY.

关键词： Molecular dynamics

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Learning local feature descriptor with motion attribute for vision-based localization

arXiv

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arXiv 2019年

作者： Song, Yafei Zhu, Di Li, Jia Tian, Yonghong Li, Mingyang AI Labs Alibaba Group Hangzhou311121 China National Engineering Laboratory for Video Technology School of Electronics Engineering and Computer Science Peking University Beijing100871 China National Key Laboratory of Virtual Reality Technology and System School of Computer Science and Engineering Beihang University Beijing100191 China

关键词： Machine learning

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