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Hashtag Recommendation Based on Multi-Features of Microblogs

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Journal of Computer Science & Technology 2018年第4期33卷 711-726页

作者： fei-fei kou Jun-Ping Du Cong-Xian Yang Yan-Song Shi Wan-Qiu Cui Mei-Yu Liang Yue Geng Beijing Key Laboratory of Intelligent Telecommunication Software and Multimedia School of Computer Science Beijing University of Posts and Telecommunications Beijing 100876 China

Hashtag recommendation for microblogs is a very hot research topic that is useful to many applications involving microblogs. However, since short text in microblogs and low utilization rate of hashtags will lead to the data sparsity problem, it is difficult for typical hashtag recommendation methods to achieve accurate recommendation. In light of this, we propose HRMF, a hashtag recommendation method based on multi-features of microblogs in this article. First, our HRMF expands short text into long text, and then it simultaneously models multi-features （i.e., user, hashtag, text） of microblogs by designing a new topic model. To further alleviate the data sparsity problem, HRMF exploits hashtags of both similar users and similar microblogs as the candidate hashtags. In particular, to find similar users, HRMF combines the designed topic model with typical user-based collaborative filtering method. Finally, we realize hashtag recommendation by calculating the recommended score of each hashtag based on the generated topical representations of multi-features. Experimental results on a real-world dataset crawled from Sina Weibo demonstrate the effectiveness of our HRMF for hashtag recommendation.

关键词： hashtag recommendation topic model collaborative filtering method microblog

FAST interstellar scintillation observation of PSR B1929+10 and PSR B1842+14

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Research in Astronomy and Astrophysics 2020年第5期20卷 175-180页

作者： Ju-Mei Yao Wei-Wei Zhu Pei Wang Di Li Ji-Guang Lu fei-fei kou Ye-Zhao Yu Bo Peng FAST Collaboration CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Xinjiang Astronomical Observatories Chinese Academy of SciencesUrumqi 830011China School of Physics and Electronics Qiannan Normal University for NationalitiesDuyun 558000China

In this paper,we present the Five-hundred-meter Aperture Spherical radio Telescope(FAST)observations of PSRs B1929+10 and B1842+*** analysis of the pulsars’scintillation pattern,we detected the known scintillation arc from PSR B1929+10 and two previously undetected scintillation arcs from B1842+*** find that the B1929+10 arc’s curvature scales with observing frequency asη-∝ν-2.1±0.1 andη+∝ν-1.8±0.2,consistent with Arecibo results and the theoretical expectations ofη∝ν-*** the arc curvature,we infer the scattering screen to be located at 0.20±0.02 kpc from the Earth,close to what was measured by RadioAstron at 324 *** B1842+14,we find two scintillation arcs for the first *** arcs’curvatures imply that they are caused by two scattering screens located at a distance of 0.3±0.2 kpc and 1.6±0.6 kpc from the Earth,*** screen distance uncertainties mainly come from the uncertainty in pulsar’s dispersion measure(DM)-derived *** present these FAST scintillation observations and discuss the future prospect of FAST pulsar scintillation study.

关键词： FAST pulsars:general ISM:structure

Spin-down and emission variations for PSR J0742-2822

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Research in Astronomy and Astrophysics 2021年第2期21卷 142-148页

作者： Shi-Jun Dang Na Wang Hui-Hui Wang Jian-Ping Yuan Lun-Hua Shang Rai Yuen Ming-Yu Ge Xia Zhou Shuang-Qiang Wang fei-fei kou Wen-Ming Yan Jing-Bo Wang Zhi-Gang Wen Jun-Tao Bai Zhi-Yong Liu Zu-Rong Zhou Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences 19A Yuquan RoadBeijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China School of Physics Huazhong University of Science and TechnologyWuhan 430074China School of Electronic and Optical Engineering Nanjing University of Science and TechnologyNanjing 210094China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guizhou Normal UniversityGuiyang 550001China

PSR J0742-2822 is known for its quasi-periodic changes in the observed pulse profile and spindown *** this paper,we analyzed 13 years of timing data obtained with the Nanshan 25-m radio telescope and the Parkes 64-m radio *** found that the average values of the spin-down rate((v))of this pulsar changed in four different *** investigated the correlation between v and W50,and ascertained that the correlation changed in different ***,not all the changes in states and correlation can be associated with glitch *** examined the long term evolution ofγ-ray flux(0.1-300 GeV)and the pulse profiles corresponding to the four different states using Fermi-LAT Pass8(P8 R3)data from 2008 August 5 to 2019 October *** did not detect a significant change inγ-ray flux or the pulse *** results suggest that the connection between pulsar rotation and emission is more complex than previously reported for this pulsar.

关键词： pulsars general-stars pulsar-methods timing

Detection of 16 Small Glitches in Nine Pulsars

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Research in Astronomy and Astrophysics 2022年第9期22卷 88-97页

作者： Zu-Rong Zhou Jing-Bo Wang Na Wang Jian-Ping Yuan fei-fei kou Shi-Jun Dang Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Xinjiang Key Laboratory of Radio Astrophysics Urumgi 830ollChina Key Lab of Radio Astronomy Chinese Academy of SciencesBeijing l0010lChina School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China

Pulsar timing measurements with a 26 m radio telescope at Nanshan between 2000 and 2014 were used to search for glitch events. The data span of nine pulsars ranges from 11.6 to 14.2 yr, and 16 new glitch events were identified in nine pulsars. Glitch parameters were determined through fitting the timing residuals data. All 16 glitches have a small fractional size. Six new glitches have been detected in PSR J1833-0827, making it another frequent glitching pulsar. Some of the 16 glitches may experience exponential or linear recovery, but it is unlikely for us to make further analyses with the large gap in the data set. All the glitch rates obtained from Nanshan are higher than that from Jodrell Bank Observatory. The small glitch size and high glitch rate could possibly attribute to the high observation cadence.

关键词： stars:neutron methods:data analysis (stars:)pulsars:general

DLP printing of BT/HA nanocomposite ceramic scaffolds using low refractive index BT crystals

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Journal of Materiomics 2024年第5期10卷 1036-1048页

作者： Ruixuan Xue Peimei Yuan Bo Zhao fei Jing Xuyuan kou Wangyang Yue Yan wang Dongmei Wang Galhenage Asha Sewvandi Dengwei Hu Faculty of Chemistry and Chemical Engineering Baoji University of Arts and SciencesKey Laboratory of Functional Materials of Baoji Engineering Research Center for Titanium Based Functional Materials and DevicesUniversities of Shaanxi Province1 Hi-Tech AvenueBaoji721013ShaanxiChina Department of Materials Science and Engineering Faculty of EngineeringUniversity of MoratuwaKatubeddaSri Lanka

Biological piezoelectric materials have significant potential for bone repair and energy harvesting owing to their excellent biocompatibility and piezoelectric *** BaTiO3/Ca10(PO4)6(OH)2(BT/HA)composite material is an outstanding representative of biological piezoelectric materials,which has not been individually designed using digital light processing(DLP)3D printing because of the large difference in the refractive index of its ***,in this work,double-sided-tooth plate-like BT crystals with high curvature were prepared via a hydrothermal process,and BT/HA ceramic slurries were grinded out using dispersed intermittent ball milling scheme,and BT/HA nanocomposite ceramic scaffolds were fabricated by DLP 3D printing *** nanostructure,dielectric properties,and piezoelectric energy harvesting performance of the BT/HA nanocomposite ceramic scaffolds were *** influences of different morphologies and contents for BT on the piezoelectric potential and stress distribution were analyzed based on a multi-physics coupling finite element *** cell proliferation and adhesion abilities were investigated *** BT/HA nanocomposite ceramic scaffolds present excellent dielectric properties,cell proliferation and adhesion abilities,and an open circuit voltage of 8 V during piezoelectric energy *** material properties and multi-physics coupling finite element analysis imply that the double-sided-tooth plate-like BT plays an important role for the fastness structure and electric field distribution in the BT/HA ***,this work provides a strategy for the application of the customized BT/HA nanocomposite ceramic scaffolds in new-generation orthopedic implants and biological energy harvesting.

关键词： 3D printing BT/HA nanocomposite ceramics Bio-piezoelectric scaffolds Energy harvesting

基于CiteSpace软件分析的太赫兹超材料器件研究

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光谱学与光谱分析 2024年第4期44卷 910-917页

作者：戴林林苏晋寇菲菲亓丽梅孙丹丹石丹北京邮电大学电子工程学院北京100876 山东师范大学光操作与应用协同创新中心山东济南250358

超材料具备天然材料没有的电磁性质,基于超材料的太赫兹(THz)功能器件在生物分子检测、医学成像、安全检查等领域都具有广泛的应用前景。采用CiteSpace软件对2016年—2023年web of science网站上有关太赫兹超材料功能器件的参考文献进... 详细信息

超材料具备天然材料没有的电磁性质,基于超材料的太赫兹(THz)功能器件在生物分子检测、医学成像、安全检查等领域都具有广泛的应用前景。采用CiteSpace软件对2016年—2023年web of science网站上有关太赫兹超材料功能器件的参考文献进行了可视化分析,综述了THz超材料功能器件的研究进展、热点领域,并对其发展前景进行了预测,从而为从事相关研究的工作人员提供借鉴。此次分析共检索到紧密相关文献2159篇。论文从发表文献的国家、机构和作者贡献、被引次数和关键词聚类等多方面分别进行了分析和讨论。得到了最近几年THz超材料功能器件的研究领域,主要包括吸波器、滤波器、电磁诱导透明、调制器、非对称传输、波前调控、编码超表面、机器学习、生物传感和量子纠缠超表面等。研究发现在THz超材料功能器件领域,中国发文量占所有文章总数的50%以上,英国、中国、美国这三个国家的影响力最高。通过对科研机构的合作网络分析,发现发文量排名前十位的科研机构均是中国单位,其中天津大学发文量占据第一位。通过对论文作者的共现分析和共被引分析,可以分别统计出作者的发文数量和影响力。为进一步研究THz超材料功能器件的研究热点,对关键词进行了聚类分析,得到了11个集群,总结了5个关键研究领域。最后给出了研究领域的分布图,以知识树的形式分析了各个领域的发展现状。其中吸波器、滤波器、调制器、电磁诱导透明等领域已经研究成熟。生物传感、非对称传输、天线等领域处于发展阶段,并逐渐成熟。机器学习、量子纠缠超表面成为未来的研究热点。

关键词：超材料太赫兹功能器件 CiteSpace

Results of 23 yr of Pulsar Timing of PSR J1453-6413

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Research in Astronomy and Astrophysics 2023年第10期23卷 357-366页

作者： Wei Li Shi-Jun Dang Jian-Ping Yuan Lin Li Wei-Hua Wang Lun-Hua Shang Na Wang Qing-Ying Li Ji-Guang Lu fei-fei kou Shuang-Qiang Wang Shuo Xiao Qi-Jun Zhi Yu-Lan Liu Ru-Shuang Zhao Ai-Jun Dong Bin Zhang Zi-Yi You Yan-Qing Cai Ya-Qin Yang Ying-Ying Ren Yu-Jia Liu Heng Xu School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guizhou Normal UniversityGuiyang 550001China Guizhou Radio Astronomy Observatory Guizhou UniversityGuiyang 550025China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China School of Physics Science and Technology Xinjiang UniversityUrumqi 830046China College of Mathematics and Physics Wenzhou UniversityWenzhou 325035China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

In this paper,we presented the 23.3 yr of pulsar timing results of PSR J1456-6413 based on the observations of Parkes 64 m radio *** detected two new glitches at MJD 57093(3)and 59060(12)and confirmed its first glitch at MJD 54554(10).The relative sizes(Δν/ν)of these two new glitches are 0.9×10^(-9)and 1.16×10^(-9),*** the“Cholesky”timing analysis method,we have determined its position,proper motion,and two-dimensional transverse velocities from the data segments before and after the second glitch,***,we detected exponential recovery behavior after the first glitch,with a recovery timescale of approximately 200 days and a corresponding exponential recovery factor Q of approximately 0.15(2),while no exponential recovery was detected for the other two *** interestingly,we found that the leading component of the integral pulse profile after the second glitch became stronger,while the main component became *** results will expand the sample of pulsars with magnetosphere fluctuation triggered by the glitch event.

关键词： Stars (stars:)pulsars:individual(PSR J1453-6413) stars:neutron

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基于融合特征的泄漏信号分类识别方法

强激光与粒子束 2024年第4期36卷 129-136页

作者：寇云峰戴飞赵治国吕剑明马谢成都新欣神风电子科技有限公司成都611731 北京航空航天大学北京100083 中国电子科技网络信息安全有限公司成都610041

随着移动通信、物联网、车联网、工业互联网等网络的发展,电磁环境日益复杂,非法电子设备也日渐增多,各类信号耦合互调现象严重,这给泄漏信号类型识别带来了难题。提出基于融合特征的泄漏信号分类识别方法,综合运用高维度特征提取方法... 详细信息

随着移动通信、物联网、车联网、工业互联网等网络的发展,电磁环境日益复杂,非法电子设备也日渐增多,各类信号耦合互调现象严重,这给泄漏信号类型识别带来了难题。提出基于融合特征的泄漏信号分类识别方法,综合运用高维度特征提取方法和图形化降维表征方法,结合残差网络等深度学习模型与特征融合分析方法,能够更综合地区分多类电磁泄漏信号,特征抗噪声鲁棒性高,方法可解释性好,可支撑基于电磁信号类型识别的辐射源智能检测工程应用。

关键词：电磁辐射泄漏信号信号识别特征提取智能检测

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电化学脱卤氘化研究进展

电化学（中英文） 2024年第5期30卷 1-10页

作者：李鹏飞寇广生亓丽萍仇友爱南开大学化学院元素有机化学国家重点实验室天津300071

近年来,含有氘原子的化合物在包括材料和生物医药在内的各个领域中的重要性日益增加,被广泛应用于化学和生物学的机制研究中,将氘原子引入有机化合物已经成为药物分子发展的重要方向之一。同时,在非生物活性物质的活体内氚标记的化合物... 详细信息

近年来,含有氘原子的化合物在包括材料和生物医药在内的各个领域中的重要性日益增加,被广泛应用于化学和生物学的机制研究中,将氘原子引入有机化合物已经成为药物分子发展的重要方向之一。同时,在非生物活性物质的活体内氚标记的化合物也发挥了重要作用。自美国食品药品监督管理局(FDA)批准的第一种用于临床治疗的氘化药物问世以来,氘标记的化合物就迅速成为人们关注的焦点,各种有机化合物的氘化方法被广泛开发。其中,卤化物的还原氘化具有高选择性的优势,但是大部分反应策略受到氘源和催化模式的限制。有机电合成作为一种相对绿色的催化模式以及其对氧化还原反应的广泛适应性,电化学卤化物的还原氘化成为替代传统卤-氘原子交换的重要方法之一,它避免了传统方法中过渡金属催化剂、金属试剂及昂贵氘代试剂的使用。近年来卤化物的电化学脱卤氘化得到很快的的发展,电化学脱卤氘化通常仅需要重水作为最廉价易得的氘源就能高效得到高氘代掺入率的产物,这为氘代化合物的合成与发展提供了重要的支撑。本文根据卤化物的类型,综述了电化学条件下芳基卤化物和烷基卤化物还原氘化的最新进展以及其反应机制,有望为未来更为广泛的氘代方法研究以及氘代化合物的研究提供一定的基础.

关键词：电化学氘化卤化物氘水脱卤反应