http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Pengyue Zhao,Yongbo Guo 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.1
Polycrystalline materials can be divided into four types of microstructural components, including grain cell (GC), grain boundary (GB), triple junction (TJ) and vertex points (VP). Nanoindentation at different microstructural components on the polycrystalline materials surface can lead to different plastic deformation behaviors of the polycrystalline materials. Due to experimental limitations, the indentation-induced internal stress and defect evolution process are difficult to investigate directly, especially for the polycrystalline materials with grain size less than 100 nm. The molecular dynamics (MD) simulations were performed to unravel the initial indentation position effect on the elasticity/plastic deformation mechanism of polycrystalline copper. The results reveal that the initial indentation position governs the indentation force variation and defect distribution range due to the different dimensionalities of the microstructural components. The defect propagation as well as the internal stress transmission in the GC regions tend to transfer to the low-dimensional microstructural components of the interfaces. In addition, the atomic internal stress and potential energy accumulation/release of the microstructural component atoms during the nanoindentation process are also investigated, revealing that the atomic internal stress and potential energy in the VPs vary earliest, followed by the TJs, GBs and GCs.
Ensemble learning-based hierarchical retrieval of similar cases for site planning
Wang Pengyue,Guo Maozu,Han Yunsong,Zhao Lingling,Zhou Xiaoping,Zhang Dayu 한국CDE학회 2021 Journal of computational design and engineering Vol.8 No.6
Site planning not only involves the arrangement of a large number of elements but also considers the complexity of urban systems; hence, the design process involves large workloads and is time consuming. Retrieving similar existing cases helps architects optimize or accelerate the design process. This paper proposes a computational approach that provides valuable references by retrieving similar cases. Three types of attributes are extracted to represent a given parcel: land-use attributes, geometric attributes (area, orientation, etc.), and environmental attributes (greening rate, surrounding facilities, etc.). The complete hierarchical retrieval process is divided into three phases. The first phase selects cases whose land-use attributes are consistent with the target parcel. Then, the similarity distances between the given target parcel and the selected cases are calculated using geometric attributes. The eXtreme Gradient Boosting (XGBoost) classifier is adopted to determine which case is similar to the target parcel. Finally, similarity scores of the retrieved cases are calculated based on the environmental attributes to provide more options during the actual design. In total, 1189 cases with different land-use types in Beijing were collected for the case base. The comparative experimental results confirmed that the proposed ensemble learning-based hierarchical retrieval of similar cases approach improves the accuracy of retrieval results. Furthermore, we use a real-world target parcel to demonstrate the superiority and flexibility of the retrieval process.
Magnetic Microstructures and Corrosion Behaviors of Nd-Fe-B-Ti-C Alloy by Ga Doping
Qiong Wu,Pengyue Zhang,Hongliang Ge,Aru Yan,Dongyun Li 한국자기학회 2013 Journal of Magnetics Vol.18 No.3
The influences of Gallium doping on the magnetic microstructures and corrosion behaviors of Nd-Fe-B-Ti-C alloys are investigated. The cooling rate for obtaining fully amorphous structure is raised, and the glassforming ability is improved by the Ga addition. The High Resolution Transmission Electron Microscopy image shows that the α-Fe and Fe3B soft magnetic phases become granular surrounded by the Nd2Fe14B hard magnetic phase. The rms and (Δ?)rms value of Nd-Fe-B-Ti-C nanocomposite alloy thick ribbons in the typical topographic and magnetic force images detected by Magnetic Force Microscopy(MFM) decreases with 0.5 at% Ga addition. The corrosion resistances of Nd9Fe73B₁₂.6C ₁.₄Ti₄-xGax (x = 0, 0.5, 1) alloys are enhanced by the Ga addition. It can be attributed to the formation of more amorphous phases in the Ga doped samples.
Sihao Hua,Pengyue Zhang,Hangfu Yang,Suyin Zhang,Hongliang Ge 한국자기학회 2013 Journal of Magnetics Vol.18 No.4
This paper studies the effects of A-site substitution by barium on the magnetic and magnetocaloric properties of Pr0.5Sr0.5-xBaxMnO₃ (x = 0, 0.04, 0.08 and 0.1). The tetragonal crystal structures of the samples are confirmed by room temperature X-ray diffraction. The dependence of the Curie temperature (TC) and the magnetic entropy change (ΔSM) on the Ba doping content has been investigated. The samples of all doping contents undergo the second order phase transition. As the concentration of Ba increased, the maximum entropy change (|ΔSM|max) increased gradually, from 1.15 J kg<SUP>?1</SUP> K<SUP>?1</SUP> (x = 0) to 1.36 J kg<SUP>?1</SUP> K<SUP>?1</SUP> (x = 0.1), in a magnetic field change of 1.5 T. The measured value of TC is 265 K, 275 K, 260 K and 250 K for x = 0, 0.04, 0.08 and 0.1, respectively. If combining these samples for magnetic refrigeration, the temperature range of ~220 K and 290 K, where |ΔSM|max is stable at ~1.27 J kg<SUP>?1</SUP> K<SUP>?1</SUP> and RCP = 88.9 Jㆍg<SUP>?1</SUP> for ΔH = 1.5 T. Pr0.5Sr0.5-xBaxMnO₃ compounds, are expected to be suitable for magnetic-refrigeration application due to these magnetic properties.
Sihao Hua,Pengyue Zhang,Hangfu Yang,Suyin Zhang,Hongliang Ge 한국자기학회 2013 Journal of Magnetics Vol.18 No.1
This paper studies the effects of the Mn-site substitution by nickel on the magnetic properties and the magnetocaloric properties of La0.7Ca0.3Mn1-xNixO₃ (x = 0, 0.05 and 0.1). The orthorhombic crystal structures of the samples are confirmed by the room temperature X-ray diffraction. The dependence of the Curie temperature (TC) and the magnetic entropy change (ΔSM) on the Ni doping content was investigated. The samples with x = 0 had the first order phase transition, while the samples with x = 0.05 and 0.1 had the second order phase transition. As the concentration of Ni increased, the maximum entropy change (|ΔSM|max) decreased gradually, from 2.78 Jㆍ㎏?¹ㆍK?¹ (x = 0) to 1.02 Jㆍ㎏?¹ㆍK?¹ (x = 0.1), in a magnetic field change of 15 kOe. The measured value of TC was 185 K, 150 K and 145 K for x = 0, 0.05 and 0.1, respectively. The phase transition temperatures became wider as x increased. It indicates that the Mn-site substitution by Ni may be used to tailor the Curie temperature in La0.7Ca0.3Mn1-xNixO₃.
Magnetic and Structural Properties of MnBi<SUB>1-x</SUB>Ti<SUB>x</SUB> Alloys
Suyin Zhang,Pengyue Zhang,HuanChang Jiang,Yaojun Shi,Nengjun Yu,Hongliang Ge 한국자기학회 2014 Journal of Magnetics Vol.19 No.3
MnBi1-xTix (x = 0, 0.4, 0.7, 1) alloys were prepared by arc-melting, followed by heat treatment. X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) were used to measure and investigate the phase structure and magnetic properties. The temperature dependent magnetization curves indicate that the phase transitions between LTP and HTP MnBi occur with heating or cooling in MnBi1-xTix (x ≤ 0.7) samples. However, MnTi samples are in Mn₂Ti single-phase, with very low magnetic properties. Furthermore, the coercivity exhibits a positive temperature coefficient. The results show that the optimal content of Ti for the coercivity of MnBi1-xTix alloy is x = 0.4. For MnBi sample, the coercivity reaches a maximum value of 1.13 T at 550 K. However, the remanence and energy product show apparent decrease with the addition of Ti in MnBi1-xTix alloys.
Zhang, Suyin,Zhang, Pengyue,Liu, Xin,Yang, Zhexi,Huang, Yanlin,Seo, Hyo Jin Elsevier 2018 Journal of luminescence Vol.203 No.-
<P><B>Abstract</B></P> <P>A series of novel red-emitting phosphor of Li<SUB>5</SUB>La<SUB>3–3x</SUB>Eu<SUB>3x</SUB>Ti<SUB>2</SUB>O<SUB>12</SUB> (x = 0.01–0.25) were synthesized via the facile solid-state reaction method. The Rietveld refinements verified that all the samples crystallized in a garnet-like cubic structure. The band gap energy of Li<SUB>5</SUB>La<SUB>3</SUB>Ta<SUB>2</SUB>O<SUB>12</SUB> is 3.87 eV, which can be greatly narrowed by Eu<SUP>3+</SUP>-doping. This benefits the red-shift of optical absorption from UV- to near-UV light region. Importantly, the sample presents dominant absorption in near-UV (390–395 nm) and blue-light (460–465 nm) region. Li<SUB>5</SUB>La<SUB>3–3x</SUB>Eu<SUB>3x</SUB>Ta<SUB>2</SUB>O<SUB>12</SUB> (x = 0.01–0.15) has a bright red-luminescence with the strongest <SUP>5</SUP>D<SUB>0</SUB> → <SUP>7</SUP>F<SUB>2</SUB> transition at 613 nm. The energy transfer was discussed on the Eu<SUP>3+</SUP>-doping concentration. The experimental red-emitting lamps were fabricated using a 395 and a 460 nm LED-chips, respectively, in combination with the single phosphor of Li<SUB>5</SUB>La<SUB>3–3x</SUB>Eu<SUB>3x</SUB>Ta<SUB>2</SUB>O<SUB>12</SUB> (x = 0.2) driven by 2 mA current. The results indicate that the phosphor could be a promising candidate used in solid-state lightings and displays.</P>
Optimization of a double crystal monochromator
Jiang Zheng,Wang Eryan,Song Ruiqiang,Guo Siming,Wu Jinjie,Hou Dongjie,An Zhenghua,Zhou Pengyue 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.79 No.8
The double crystal diffraction structure based on Bragg diffraction is the core component of the monochromator that is widely used in synchrotron radiation beam lines and monochromatic X-ray radiation devices. The stability of monochromatic X-rays produced by using the T-structure double crystal monochromator at National Institute of Metrology was investigated experimentally. Due to its structural defects, the X-ray flux of the T-structured double crystal monochromator shows poor long-term stability. Inspired by the Channel-cut monochromator structure, we designed a new double crystal monochromator structure to improve the long-term stability of the X-ray flux. Experiments showed that the stability of the monochromatic X-ray flux for the new double crystal monochromator structure was better than 1.0%@1 h, and the energy region and flux rate of the monochromatic X-rays are significantly improved. This work provides a stable and reliable monochromatic X-ray source for the calibration of X/γ detectors such as satellite load detectors, which will contribute to the development of X/γ detection technology.