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Effect of coarse TiN inclusions and microstructure on impact toughness fluctuation in Ti micro-alloyed steel

Journal of Iron and Steel Research International 2018年第10期25卷 1043-1053页

作者： Tao Liu Mu-jun Long Deng-fu Chen Hua-mei Duan Lin-tao Gui sheng Yu jun-sheng cao Hua-biao Chen He-lin Fan State Key Laboratory of Coal Mine Disaster Dynamics and Control College of Materials Science and Engineering Chongqing University Chongqing 400044 China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing University Chongqing 400044 China

Toughness is an important property for steels used in engineering applications. However, recent toughness testing has shown the existence of a significant fluctuation in toughness in a single rolled plate of titanium micro-alloyed steel. The underlying causes of this fluctuation were investigated by fractography, analysis of microstructure and measurement of inclusions. Coarse and distributed TiN inclusions were responsible for the toughness variation, as they tended to act as the potential cleavage initiators to form micro-cracks. From a calculation of the local fracture stress, the critical size of coarse TiN inclusions for dominating micro-crack propagation was 4.93 μm, and similarly that of ferrite grains was 36.6μm. Under current casting and thermo-mechanically controlled processing schedules, the toughness fluctuation of rolled steel plates can be primarily attributed to the fraction of coarse TiN inclusions larger than 5μm. A corresponding relationship between impact energy and the proportion of coarse TiN inclusions was established. Finally, a normalizing treatment was applied to refine the ferrite grains of rolled steel plates. Despite the presence of coarse TiN inclusions, this refinement in ferrite grains minimized the toughness fluctuation and improved the uniformity of the impact properties of the steel plates.

关键词： Impact toughness fluctuation Ti micro-alloyed steel Cleavage fracture Coarse TiN inclusion Grain refinement

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Effect of Mg and Fe Doping on Optical Absorption of LiNbO3 Crystal through First Principles Calculations

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Chinese Physics Letters 2014年第3期31卷 125-128页

作者： HUANG Duo-Hui YANG jun-sheng cao Qi-Long WAN Ming-Jie LI Qiang SUN Liang WANd Fan- Hou Computational Physics Key Laboratory of Sichuan Province Yibin University Yibin 644007

Using first principles calculations, we investigate the structural, optical, and electronic properties of LiNbO3 （LN） and M doped LN （M=Mg, Fe）. The density of states are calculated to analyze the effect of doping Mg and Fe ions on the absorption spectra and electronic properties of LN. The results show an ultraviolet shift in the optical absorption edge of Mg-doped LN compared with that of intrinsic LN. On the contrary, the absorption edge of Fe-doped LN crystal reveals a red shift. The optical absorption spectra show an improved optical response in the visible range for Mg-doped LN, which significantly differs from that obtained for Fe-doped LN. The electronic excitations from the valence band to the conduction band of LN leads to an improved optical absorption response in the visible region as observed experimentally. The obvious changes of the doped LN crystal are found in some cases, which provide a helpful guide for preparing doped LN crystal.

关键词： LITHIUM niobate -- Optical properties RESEARCH SEMICONDUCTOR doping LIGHT absorption MAGNESIUM PHYSICS research

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基于事件条件动作规则的智能主体结构

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上海交通大学学报 2004年第1期38卷 14-17页

作者：周晓俊张申生曹健戴开宇上海交通大学计算机科学与工程系上海200030

为了增强智能主体能力及方便地实现一个智能主体系统,在抽象语言AgentSpeak(L)基础上,引入事件条件动作规则,并从功能和实现的角度对心智模型进行必要扩充和完善.定义了E-Agent的心智模型,设计了E-Agent的Agent描述语言,给出了E-Agent... 详细信息

为了增强智能主体能力及方便地实现一个智能主体系统,在抽象语言AgentSpeak(L)基础上,引入事件条件动作规则,并从功能和实现的角度对心智模型进行必要扩充和完善.定义了E-Agent的心智模型,设计了E-Agent的Agent描述语言,给出了E-Agent的解释执行过程.实现了一个包括可视化建模工具和运行环境的智能主体系统.该系统具有可视化建模、易于使用等优点.

关键词：智能主体事件条件动作规则规划

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The Mechanism of Heating Rate on the Secondary Recrystallization Evolution in Grain Oriented Silicon Steel

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期 275-282页

作者：高倩 LI jun WANG Xianhui cao Laifu GONG Jian LI Bo Central Iron and Steel Research Institute Group Shougang Zhixin Electromagnetic Material R&D (Beijing) Co. Ltd. Beijing Shougang Co. Ltd.

Grain-oriented silicon steels were prepared at different heating rates during high temperature annealing, in which the evolution of magnetic properties, grain orientations and precipitates were studied. To illustrate the Zener factor, the diameter and number density of precipitates of interrupted testing samples were statistically calculated. The effect of precipitate ripening on the Goss texture and magnetic property was investigated. Data indicated that the trend of Zener factor was similar under different heating rates, first increasing and then decreasing, and that the precipitate maturing was greatly inhibited as the heating rate increased. Secondary recrystallization was developed at the temperature of 1 010 ℃ when a heating rate of 5 ℃/h was used, resulting in Goss, Brass and {110} oriented grains growing abnormally and a magnetic induction intensity of 1.90T. Furthermore, increasing the heating rate to 20 ℃/h would inhibit the development of undesirable oriented grains and obtain a sharp Goss texture. However, when the heating rate was extremely fast, such as 40 ℃/h, poor secondary recrystallization was developed with many island grains, corresponding to a decrease in magnetic induction intensity to 1.87 T. At a suitable heating rate of 20 ℃/h, the sharpest Goss texture and the highest magnetic induction of 1.94 T with an onset secondary recrystallization temperature of 1 020 ℃ were found among the experimental variables in this study. The heating rate affected the initial temperature of secondary recrystallization by controlling the maturation of precipitates, leading to the deviation and dispersion of Goss texture, thereby reducing the magnetic properties.

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Equivalent circuit model for the insulated core transformer

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Nuclear Science and Techniques 2016年第3期27卷 132-137页

作者： Bo Yang Lei cao jun Yang sheng-Chi Yan Yi-Bin Tao China Electric Power Research Institute Nanjing 210003China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhan 430074China

The design of the insulated core transformer(ICT)needs to consider the flux leakage *** equivalent linear circuit model is proposed based on the principle of *** is composed by two types of leakage inductances:conventional leakage between windings and special leakage introduced mainly by the insulation *** values of leakage inductances depend on the dimensions of the core,gaps,or windings and the property of magnetic *** circuit allows for quantitatively evaluating influences of ICT internal parameters on its output *** winding self- and mutual inductance matrix is mathematically converted to derive the inductance *** an example,the leakage parameters of a sixstage two-dimensional(2D) ICT are calculated and analyzed.

关键词：等效电路模型变压器绝缘性能影响电感计算对偶原理等效线性磁性材料

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Alcohol Solvent Effect on Fluorescence Properties in the Solvothermal Synthesis of Carbon Quantum Dots

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Journal of Wuhan University of Technology(Materials Science) 2022年第1期37卷 23-27页

作者： DENG Yafeng ZHOU Yihua YE Shuangli QIAN jun cao sheng School of Printing and Packaging Wuhan UniversityWuhan 430079China Wuhan Donghu University Wuhan 430079China

Highly monodisperse carbon quantum dots(CQDs)were synthesized by a solvothermal method using L-ascorbic acid as carbon source and different simple alcohols(methanol,ethanol,ethylene glycol,and isopropanol)as reaction solvents at 180℃for 4 *** performance of CQDs was characterized by transmission electron microscope(TEM),Fourier infrared spectrometer(FTIR),UV-visible spectrophotometer,and fluorescence *** results show that the prepared CQDs are wavelength-dependent,and have good hydrophilicity and similar surface ***,there are more carbon and oxygen-containing functional groups on the surface of CQDs prepared with ethanol(CQDs-ET),and the type and number of functional groups will directly affect the fluorescence emission of ***,it is found that the luminescence mechanisms of CQDs prepared by this solvothermal method are mainly based on the defect state of the oxygen group *** alcohol solvents do not directly participate in the formation of carbon nuclei during the reaction process,but it will affect the number and type of surface ***,the influence of surface groups on the CQDs performance is greater than that of carbon nuclei in this experiment.

关键词： carbon quantum dots solvothermal method reaction solvent luminescence mechanisms

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Estimates of Soil Organic Carbon Stocks in Zhejiang Province of China Based on 1:50000 Soil Database Using the PKB Method

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Pedosphere 2015年第1期25卷 12-24页

作者： ZHI jun-jun JING Chang-Wei LIN sheng-Pan ZHANG cao WU Jia-Ping College of Environmental and Resource Sciences Zhejiang University Institute of Islands and Coastal Research Zhejiang University Department of Zoology Michigan State University

Soil organic carbon(SOC) is an important component of farming systems and global carbon cycle. Accurately estimating SOC stock is of great importance for assessing soil productivity and modeling global climate change. A newly built 1:50 000 soil database of Zhejiang Province containing 2 154 geo-referenced soil profiles and a pedological professional knowledge-based(PKB) method were used to estimate SOC stock up to a depth of 100 cm for the Province. The spatial patterns of SOC stocks stratified by soil types,watershed(buffer analysis), topographical factors, and land use types were identified. Results showed that the soils in Zhejiang covered an area of 100 740 km2 with a total SOC stock of 831.49 × 106 t and a mean SOC density of 8.25 kg m-2, excluding water and urban areas. In terms of soil types, red soils had the highest SOC stock(259.10 × 106t), whereas mountain meadow soils contained the lowest(0.15 × 106t). In terms of SOC densities, the lowest value(5.11 kg m-2) was found in skel soils, whereas the highest value(45.30 kg m-2) was observed in mountain meadow soils. Yellow soils, as a dominant soil group, determined the SOC densities of different buffer zones in Qiantang River watershed because of their large area percentage and wide variation of SOC density *** area percentages of various soil groups significantly varied with increasing elevation or slope when overlaid with digital elevation model data, thus influencing the SOC densities. The highest SOC density was observed under grassland, whereas the lowest SOC density was identified under unutilized land. The map of SOC density(0–100 cm depth) and the spatial patterns of SOC stocks in the Province would be helpful for relevant agencies and communities in Zhejiang Province, China.

关键词： elevation pedological professional knowledge-based method sampling depth slope SOC density soil groups

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In Vitro Biocompatibility of MC3T3-E1 Osteoblast-like Cells on Arg-Gly-Asp Acid Peptides Immobilized Graphite-like Carbon Coating on Carbon/Carbon Composites

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Acta Metallurgica Sinica(English Letters) 2017年第6期30卷 558-566页

作者： sheng cao He-jun Li Ke-Zhi Li Jin-Hua Lu Lei-Lei Zhang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China

Carbon/carbon （C/C） composites were deposited with graphite-like carbon （GLC） coating, and then, Arg-Gly- Asp acid （RGD） peptides were successfully immobilized onto the functionalized GLC coating. GLC coating was utilized to prevent carbon particles releasing and create a uniform surface condition for C/C composites. RGD peptides were utilized to improve biocompatibility of GLC coating. Surface chemical characterizations of functionalized GLC coating were detected by contact angle measurement, X-ray photoelectron spectroscopy and Raman spectra. Optical morphology of GLC coatings was observed by confocal laser scanning microscopy. In vitro biological performance was determined using samples seeded with MC3T3-E1 osteoblast-like cells and cultured for 1 week. Surface characterizations and morphological analysis indicated that C/C composites were covered by a dense and uniform GLC coating. Contact angle of GLC coating was reduced to 27.2° when it was functionalized by H202 oxidation at 40 ℃ for 1 h. In vitro cytological test showed that the RGD peptides immobilized GLC coating had a significant improvement in biocompatibility. It was suggested that RGD peptides provided GLC coating with a bioactive surface to improve cell adhesion and proliferation on C/C composites.

关键词： MC3T3-E1 osteoblast-like cells Carbon/carbon composites Graphite-like carbon (GLC) coating Arg-Gly-Asp acid (RGD) peptides Surface modification

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A review of object representation based on local features

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Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第7期14卷 495-504页

作者： Jian cao Dian-hui MAO Qiang CAI Hai-sheng LI jun-ping DU College of Computer and Information Engineering Beijing Technology and Business University School of Computer Science Beijing University of Posts and Telecommunications

Object representation based on local features is a topical subject in the domain of image understanding and computer vision. We discuss the defects of global features in present methods and the advantages of local features in object recognition, and briefly explore state-of-the-art recognition methods using local features, especially the main approaches of local feature extraction and object representation. To clearly explain these methods, the problem of local feature extraction is divided into feature region detection, feature region description, and feature space optimization. The main components and merits of these steps are presented. Technologies for object presentation are classified into three types: vector space, sliding window, and structure relationship models. Future development trends are discussed briefly.

关键词： Object presentation Local feature Image understanding Object recognition Visual words

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Analysis of S-SEED’s characteristics in optical switch

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The Journal of China Universities of Posts and Telecommunications 2008年第4期15卷 91-94页

作者： cao Yong-sheng YIN Xiao-li XIN Xiang-jun YU Chong-xiu Key Laboratory of Optical Communication and Lightwave Technologies Beijing University of Posts and Telecommunications Ministry of Education Beijing 100876 China

This article introduces the basic structure of a symmetric self-electrooptic effect device （S-SEED）, and applies the Kirchoff＇ s current law and a purely equivalent capacitive model, to analyze S-SEED＇s switch characteristics. Linear approximation and N-segment approximation are utilized to obtain S-SEED＇s voltage-time （V-T） and characteristics. Theoretical analysis is verified by simulations, and the results demonstrate that the precision of S-SEED＇s switch time can satisfy the requirement in applications with linear approximation. Moreover, the simulations compare S-SEED＇s switch characteristics with different input powers and input contrast ratios, which reveal that increasing input contrast ratio is an effective way to improve S-SEED＇s switch characteristics.

关键词： symmetry S-SEED optical switch V-T characteristics characteristic simulations

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