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Predicting Supermassive Black Hole Mass with Machine Learning Methods

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Research in Astronomy and Astrophysics 2022年第8期22卷 182-190页

作者： Yi He qi guo Shi Shao Key Laboratory for Computational Astrophysics National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

It is crucial to measure the mass of supermassive black holes(SMBHs)in understanding the co-evolution between the SMBHs and their host *** methods usually require spectral data which are expensive to *** use the AGN catalog from the Sloan Digital Sky Survey project Data Release 7(DR7)to investigate the correlations between SMBH mass and their host galaxy *** apply the machine learning algorithms,such as Lasso regression,to establish the correlation between the SMBH mass and various photometric properties of their host *** find an empirical formula that can predict the SMBH mass according to galaxy luminosity,colors,surface brightness,and *** root-mean-square error is 0.5 dex,comparable to the intrinsic scatter in SMBH mass *** 1σscatter in the relation between the SMBH mass and the combined galaxy properties relation is 0.48 dex,smaller than the scatter in the SMBH mass versus galaxy stellar mass *** relation could be used to study the SMBH mass function and the AGN duty cycles in the future.

关键词： (galaxies:)quasars:supermassive black holes galaxies:evolution methods:data analysis

Ag/C nanoparticles catalysed aerobic oxidation of diaryl and aryl（hetero） methylenes into ketones

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Nano Research 2017年第9期10卷 3261-3267页

作者： Shuangxi guo qi zh.ng Hongbo Li Huifang guo Wei He Tsinghua-Peking Joint Center for Life Sciences and School of Life Sciences Tsinghua University Beijing 100084 China Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences & Peking Union Medical College Beijing I O00SO China School of Pharmaceutical Sciences Tsinghua University 8eijing 100084 China

The aerobic oxidation of diaryl and aryl(hetero) methylenes into ketones, catalyzed by Ag/C nanoparticles under mild conditions, was successfully developed. This method features a wide scope of substrates, good yields... 详细信息

关键词： nanoparticle aerobic oxidation diaryl methylenes ketones

Multiple-Channel Local Binary Fitting Model for Medical Image Segmentation

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Chinese Journal of Electronics 2015年第4期24卷 802-806页

作者： guo qi WAng Long SHEN Shuting Department of Mathematics Harbin Institute of Technology Health Science Center Peking University

This study proposes an innovative M-L(Multiple-channel local binary fitting) model for medical image segmentation. Designed to improve upon existing image segmentation models, the M-L model introduces a regional limit function to the multi-band active contour model to enable multilayer image segmentation. The Gaussian kernel function is used to improve the previous model’s robustness, necessitating the use of a new initialization curve which enhances the accuracy of segmentation results. Compared to existing image segmentation methods, the proposed M-L model improves numerical stability and efficiency through the introduction of a new penalty term and an increased step length. This simulation experiment verifies the advantages of the new M-L model for improved medical image segmentation, including increased efficiency and usability of the model.

关键词： Gaussian curve Penalty term Multiband active contour model Image segmentation

Progress on multiphase layered transition metal oxide cathodes of sodium ion batteries

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Chinese Chemical Letters 2020年第9期31卷 2167-2176页

作者： qi Wang Shiyong Chu Shaohua guo Center of Energy Storage Materials&Technology College of Engineering and Applied SciencesJiangsu Key Laboratory of Artificial Functional MaterialsNational Laboratory of Solid State Microstructuresand Collaborative Innovation Center of Advanced MicrostructureNanjing UniversityNanjing 210093China

As one of the most promising secondary batteries in large-scale energy storage,sodium ion batteries(SIBs) have attracted wide attention due to the abundant raw materials and low *** transition metal oxides are one kind of popular cathode material candidates because of its easy synthesis and large theoretical specific ***,the most common P2 and O3 phases show distinct structural characteristics respectively.O3 phase can serve as a sodium reservoir,but it usually suffers from serious phase transition and sluggish *** the P2 phase,it allows the fast sodium ion migration in the bulk and the structure can maintain stable,but it is lack of sodium,showing a great negative effect on Coulombic efficiency in full ***,single phase structure almost cannot achieve satisfied comprehensive sodium storage *** these circumstances,exploiting novel multiphase cathodes showing synergetic effect may give solution to these *** this review,we summarize the recent development of multiphase layered transition metal oxide cathodes of SIBs,analyze the mechanism and prospect the future potential research directions.

关键词： Sodium ion batteries Cathodes Layered transition metal oxides Biphase materials Triphase materials

Typhoon wind hazard model and estimation on return period of typhoon wind speed

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Journal of Oceanology and Limnology 2021年第2期39卷 420-436页

作者： Yunxia guo Yijun HOU Peng qi Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China Laboratory for Ocean and Climate Dynamics Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

Typhoons are one of the most serious natural disasters that occur annually on China’s southeast coast.A technique for analyzing the typhoon wind hazard was developed based on the empirical track model,and used to generate 1000-year virtual typhoons for Northwest Pacific *** influences of typhoon decay model,track model,and the extreme value distribution on the predicted extreme wind speed were *** found that different typhoon decay models have least influence on the predicted extreme wind *** most of the southeast coast of China,the predicted wind speed by the non-simplified empirical track model is larger than that from the simplified tracking *** extreme wind speed predicted by different extreme value distribution is quite *** super typhoons Meranti(2016),Hato(2017),Mangkhut(2018)and Lekima(2019)were selected and the return periods of typhoon wind speeds along the China southeast coast were estimated in order to assess the typhoon wind hazard.

关键词： typhoon empirical track model decay model extreme wind speed return period

Multiple-pole solutions and degeneration of breather solutions to the focusing nonlinear Schr?dinger equation

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Communications in Theoretical Physics 2022年第4期74卷 13-22页

作者： zhao zh.ng Junchao Chen qi guo Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices South China Normal UniversityGuangzhou 510631China Department of Mathematics and Institute of Nonlinear Analysis Lishui UniversityLishui 323000China

Based on the Hirota’s method,the multiple-pole solutions of the focusing Schr?dinger equation are derived directly by introducing some new ingenious limit *** have carefully investigated these multi-pole solutions from three perspectives:rigorous mathematical expressions,vivid images,and asymptotic ***,there are two kinds of interactions between multiple-pole solutions:when two multiple-pole solutions have different velocities,they will collide for a short time;when two multiple-pole solutions have very close velocities,a long time coupling will *** last important point is that this method of obtaining multiple-pole solutions can also be used to derive the degeneration of N-breather *** method mentioned in this paper can be extended to the derivative Schr?dinger equation,Sine-Gorden equation,mKdV equation and so on.

关键词： multiple-pole solutions degenerate solutions Hirota’s bilinear method

Spheroidization of silica powders by radio frequency inductively coupled plasma with Ar–H2 and Ar–N2 as the sheath gases at atmospheric pressure

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International Journal of Minerals,Metallurgy and Materials 2017年第9期24卷 1067-1074页

作者： Lin Li guo-hua Ni qi-jia guo qi-fu Lin Peng zhao Jun-li Cheng Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China

Amorphous spherical silica powders were prepared by inductively coupled thermal plasma treatment at a radio frequency of 36.2 MHz. The effects of the added content of hydrogen and nitrogen into argon(serving as the sheath gas), as well as the carrier gas flow rate, on the spheroidization rate of silica powders, were investigated. The prepared silica powders before and after plasma treatment were examined by scanning electron microscopy, X-ray diffraction, and laser granulometric analysis. Results indicated that the average size of the silica particles increased, and the transformation of crystals into the amorphous state occurred after plasma treatment. Discharge image processing was employed to analyze the effect of the plasma temperature field on the spheroidization rate. The spheroidization rate of the silica powder increased with the increase of the hydrogen content in the sheath gas. On the other hand, the spheroidization rate of the silica power first increased and then decreased with the increase of the nitrogen content in the sheath gas. Moreover, the amorphous content increased with the increase of the spheroidization rate of the silica powder.

关键词： silica powders spheroidization inductively coupled plasma mixed gas

Direct hydrocarbon identification in shale oil reservoirs using fluid dispersion attribute based on an extended frequency-dependent seismic inversion scheme

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Petroleum Science 2023年第3期20卷 1532-1545页

作者： zhi-qi guo Tao zh.ng Cai Liu College of Geoexploration Science and Technology jilin UniversityChangchunjilin130021China SINOPEC Key Laboratory of Geophysics NanjingJjiangsu211100China SINOPEC Geophysical Research Institute NanjingJiangsu211100China

The identification of hydrocarbons using seismic methods is critical in the prediction of shale oil ***,delineating shales of high oil saturation is challenging owing to the similarity in the elastic properties of oil-and water-bearing *** complexity of the organic matter properties associated with kerogen and hydrocarbon further complicates the characterization of shale oil reservoirs using seismic ***,the inelastic shale properties associated with oil saturation can enable the utilization of velocity dispersion for hydrocarbon identification in *** this study,a seismic inversion scheme based on the fluid dispersion attribute was proposed for the estimation of hydrocarbon *** the proposed approach,the conventional frequency-dependent inversion scheme was extended by incorporating the PP-wave reflection coefficient presented in terms of the effective fluid bulk modulus.A rock physics model for shale oil reservoirs was constructed to describe the relationship between hydrocarbon saturation and shale *** to the modeling results,the hydrocarbon sensitivity of the frequency-dependent effective fluid bulk modulus is superior to the traditional compressional wave velocity dispersion of *** analysis of the inversion re-sults based on synthetics also reveals that the proposed approach identifies the oil saturation and related hydrocarbon enrichment better than the above-mentioned conventional ***,in real data applications,actual drilling results validate the superiority of the proposed fluid dispersion attribute as a useful hydrocarbon indicator in shale oil reservoirs.

关键词： Shale oil Fluid dispersion attribute Hydrocarbon identification Frequency-dependent inversion Rock physics

Rapid removal of copper impurity from bismuth-copper alloy melts via super-gravity separation

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International Journal of Minerals,Metallurgy and Materials 2021年第12期28卷 1929-1939页

作者： Xiao-chun Wen Lei guo qi-peng Bao zhan-cheng guo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

A green method of super-gravity separation,which can enhance the filtration process of bismuth and copper phases,was investigated and discussed for the rapid removal of copper impurity from bismuth-copper alloy *** separation by the super-gravity field,the bismuth-rich liquid phases were mainly filtered from the alloy melt along the super-gravity direction,whereas most of the fine copper phases were retained in the opposite *** optimized conditions of separation temperature at 280℃,gravity coefficient at 450,and separation time at 200 s,the mass proportion of the separated bismuth from the Bi-2 wt%Cu and Bi-10 wt%Cu alloys respectively reached 96%and 85%,which indicated the minimal loss of bismuth in the ***,the removal ratio of impurity copper from the Bi-2 wt%Cu and Bi-10 wt%Cu alloys reached 88%and 98%,***,the separation process could be completed rapidly and is environmentally friendly and efficient.

关键词： alloy alloys separation