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A regression approach for seismic first-break picking

Petroleum Science 2024年第3期21卷 1584-1596页

作者： Huan yuan San-Yi yuan Jie Wu Wen-Jing Sang Yu-He Zhao CNPC Key Laboratory of Geophysical Exploration China University of Petroleum(Beijing)Beijing 102249China Research Institute of Petroleum Exploration&Development—Northwest(NWGI) Key Laboratory of reservoir characterization of CNPCPetroChinaLanzhou 730020GansuChina

The picking efficiency of seismic first breaks(FBs)has been greatly accelerated by deep learning(DL)***,the picking accuracy and efficiency of DL methods still face huge challenges in low signal-to-noise ratio(SNR)*** address this issue,we propose a regression approach to pick FBs based on bidirectional long short-term memory(Bi LSTM)neural network by learning the implicit Eikonal equation of 3D inhomogeneous media with rugged topography in the target *** employ a regressive model that represents the relationships among the elevation of shots,offset and the elevation of receivers with their seismic traveltime to predict the unknown FBs,from common-shot gathers with sparsely distributed *** from image segmentation methods which automatically extract image features and classify FBs from seismic data,the proposed method can learn the inner relationship between field geometry and *** addition,the predicted results by the regressive model are continuous values of FBs rather than the discrete ones of the binary *** picking results of synthetic data shows that the proposed method has low dependence on label data,and can obtain reliable and similar predicted results using two types of label data with large *** picking results of9380 shots for 3D seismic data generated by vibroseis indicate that the proposed method can still accurately predict FBs in low SNR *** subsequent stacked profiles further illustrate the reliability and effectiveness of the proposed *** results of model data and field seismic data demonstrate that the proposed regression method is a robust first-break picker with high potential for field application.

关键词： First-break picking Low signal-to-noiseratio Regression BiLSTM Traveltime Geometry Noisy seismic data

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应用状态方程预测液化天然气的热物理性质

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石油工程建设 2018年第1期44卷 23-26页

作者：苑伟民中石化北海液化天然气有限责任公司广西北海536000

状态方程是预测和关联流体热力学性质的主要工具。将Soave-Redlich-Kwong(SRK)、PengRobins on(PR)、Le e-Ke s le r-Plocke r(LKP)和Modifie d-Be ne dict-We bb-Rubin-Starling(MBWRS)四个适用于气相和液相的状态方程用于预测液化天然气(LNG)的密度、压缩因子、焓、熵和比热容等热物理性质。HYSYS软件预测结果表明,除了比热容之外,四个状态方程预测结果都比较精确。在液化天然气热物性计算中,当流体相超出MBWRS方程适用范围时(Tr≥0.3),MBWRS状态方程的预测结果与LKP、SRK、PR方程的计算结果相比,仍然较为精确,可以用于预测液化天然气热物理性质。

关键词：状态方程液化天然气热力学性质预测

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Numerical investigation of the photo-thermal characteristics of a direct absorption solar collector using Monte Carlo and finite volume methods

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Science China(Technological Sciences) 2024年第8期67卷 2436-2448页

作者： ZHU YanLong LI SuNing FAN JianHua KONG WeiQiang yuan yuan TAN HePing School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Department of Civil Engineering and Mechanical Engineering Technical University of DenmarkKoppels AlléBuilding 4042800 Kgs.LyngbyDenmark School of Vehicle and Energy Yanshan UniversityQinhuangdao 066004China

In this study, a novel model of photothermal conversion in a direct absorption solar collector based on the Monte Carlo and finite volume methods was built and validated and the temperatures of the novel and traditional solar collectors were compared. The sensitivity of the parameters to the radiative heat loss was investigated. Finally, the radiative heat transfer characteristics were discussed using the radiative exchange factor. The results of this study validated the advantages of the novel solar collector at both the surface and fluid temperatures. Under the conditions used in this study, the maximum temperature difference of the novel solar collector was 30 K, compared with 193 K for the traditional solar collector. Furthermore, the collector was divided into several units along the flow direction. The radiative exchange factor indicated that with an increase in the attenuation coefficient, the percentage of radiation intensity in the total solar radiation absorbed by the corresponding unit ***, it decreased with an increase in the incident angle and scattering albedo. These results provide a reference for addressing the low efficiency and thermal damage caused by traditional solar collectors at high temperatures.

关键词： direct absorption solar collector radiative heat transfer Monte Carlo

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Einstein Probe discovery of EP240408a:A peculiar X-ray transient with an intermediate timescale

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Science China(Physics,Mechanics & Astronomy) 2024年

作者： Wenda Zhang weimin yuan Zhixing Ling Yong Chen Nanda Rea Arne Rau Zhiming Cai Huaqing Cheng Francesco Coti Zelati Lixin Dai Jingwei Hu Shumei Jia Chichuan Jin Dongyue Li Paul O’Brien Rongfeng Shen Xinwen Shu Shengli Sun Xiaojin Sun Xiaofeng Wang Lei Yang Bing Zhang Chen Zhang Shuang-Nan Zhang Yonghe Zhang Jie An David Buckley Alexis Coleiro Bertrand Cordier Liming Dou Rob Eyles-Ferris Zhou Fan Hua Feng Shaoyu Fu Johan P. U. Fynbo Lluis Galbany Saurabh W. Jha Shuaiqing Jiang Albert Kong Erik Kuulkers Weihua Lei Wenxiong Li Bifang Liu Mingjun Liu Xing Liu yuan Liu Zhu Liu Chandreyee Maitra Alessio Marino Itumeleng Monageng Kirpal Nandra Jeremy Sanders Roberto Soria Lian Tao Junfeng Wang Song Wang Tinggui Wang Zhongxiang Wang Qingwen Wu Xuefeng Wu Dong Xu Yanjun Xu Suijian Xue Yongquan Xue Zijian Zhang Zipei Zhu Hu Zou Congying Bao Fansheng Chen Houlei Chen Tianxiang Chen Wei Chen Yehai Chen Yifan Chen Chenzhou Cui Weiwei Cui Yanfeng Dai Dongwei Fan Ju Guan Dawei Han Dongjie Hou Haibo Hu Maohai Huang Jia Huo Zhenqing Jia Bowen Jiang Ge Jin Chengkui Li Junfei Li Longhui Li Maoshun Li Wei Li Zhengda Li Tianying Lian Congzhan Liu Heyang Liu Huaqiu Liu Fangjun Lu Laidan Luo Jia Ma Xuan Mao Haiwu Pan Xin Pan Liming Song Hui Sun Yunyin Tan Qingjun Tang Yihan Tao Hao Wang Juan Wang Lei Wang Wenxin Wang Yilong Wang Yusa Wang Qinyu Wu Haitao Xu Jingjing Xu Xinpeng Xu Yunfei Xu Zhao Xu Changbin Xue Yulong Xue Ailiang Yan Haonan Yang Xiongtao Yang Yanji Yang Juan Zhang Mo Zhang Wenjie Zhang Zhen Zhang Zhen Zhang Ziliang Zhang Donghua Zhao Haisheng Zhao Xiaofan Zhao Zijian Zhao Hongyan Zhou Yilin Zhou Yuxuan Zhu Zhencai Zhu Institut d’Estudis Espacials de Catalunya (IEEC) Max Planck Institute for Extraterrestrial Physics Innovation Academy for Microsatellites Chinese Academy of Sciences Department of Physics University of Hong Kong School of Physics and Astronomy University of Leicester School of Physics and Astronomy Sun Yat-sen University National Astronomical Observatories Department of Physics Anhui Normal University Shanghai Institute of Technical Physics Chinese Academy of Sciences Physics Department Tsinghua University Nevada Center for Astrophysics University of Nevada Las Vegas Department of Physics and Astronomy University of Nevada Las Vegas Chinese Academy of Sciences South African Astronomical Observatory Department of Astronomy University of Cape Town Department of Physics University of the Free State Universite' Paris Cite' CNRS Astroparticule et Cosmologie Universite' Paris Cite' CEA Paris-Saclay School of Astronomy and Space Sciences IRFU/DAp-AIM Department of Astronomy Guangzhou University Cosmic Dawn Center (DAWN) Niels Bohr Institute University of Copenhagen Department of Physics and Astronomy Rutgers the State University of New Jersey Institute for Cosmic Ray Research University of Chinese Academy of Sciences The University of Tokyo ESA/ESTEC Noordwijk 2201 AZ The Netherlands Department of Astronomy School of Physics Huazhong University of Science and Technology INAF-Osservatorio Astrofisico di Torino Sydney Institute for Astronomy School of Physics Key Laboratory of Particle Astrophysics The University of Sydney Department of Astronomy Xiamen University Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University Department of Astronomy University of Science and Technology Hefei School of Astronomy and Space Sciences University of Science and Technology of China Institute of High Energy Physics Institute of Deep Space Sciences Deep Space Exploration Laboratory Department of Astronomy School of Physics and Astronomy Yunnan University Shanghai Astronomical Observatory Chinese Academy of Science

We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe （EP） and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength *** new transient was first detected with Wide-field X-ray Telescope （WXT） on board EP on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for *** flare reached a peak flux of 3.9×10-9erg cm-2s-1in 0.5-4 keV,300 times brighter than the underlying X-ray emission detected throughout the *** and more precise follow-up observations by EP/FXT,Swift and NICER confirmed the finding of this new *** X-ray spectrum is non-thermal in 0.5-10 keV,with a power-law photon index varying *** X-ray light curve shows a plateau lasting for4d,followed by a steep decay till becoming undetectable10 d after the initial *** on its temporal property and constraints from previous EP observations,an unusual timescale in the range of 7-23 d is found for EP240408a,which is intermediate between the commonly found fast and long-term *** counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these *** demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical *** nature of EP240408a thus remains an *** suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of10 *** detection and follow-ups of more of such objects are essential for revealing their origin.

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Tribological evaluation of thermoplastic polyurethane-based bearing materials under water lubrication:Effect of load,sliding speed,and temperature

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Friction 2024年第8期12卷 1801-1815页

作者： Shaoli JIANG Janet SSWONG Debashis PUHAN Tian yuan Xiuqin BAI Chengqing yuan State Key Laboratory of Maritime Technology and Safety Wuhan University of TechnologyWuhan 430063China Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK Yusuf Hamied Department of Chemistry University of CambridgeLensfield RoadCambridge CB21EWUK

Polymers are widely used in bearing *** the case of water-lubricated stern tube bearings,thermoplastic polyurethane(TPU)-based composites are used due to their excellent wear resistance,corrosion resistance,and tunable mechanical *** tribological performance,however,depends on operating *** this work,TPU was blended with carbon fiber,graphene platelet,and ultra-high molecular weight polyethylene(UHMWPE).Friction tests of TPU based-composites against copper countersurface were carried out in water to mimic the actual operating conditions of the *** of the resulting contacts were in the boundary lubrication regime,in which friction was attributed to both contact mechanics of asperities as well as water *** results show that the viscoelasticity of TPU has a considerable impact on its tribological *** lubrication at 50°C promotes the softening of polymer surface material during sliding,resulting in higher fluctuation in the coefficient of friction and wear *** is attributed to the reduced thermomechanical *** addition,Schallamach waviness is observed on worn *** tribological properties of TPU are significantly improved by the inclusion of carbon fiber,graphene platelet,and *** formation of graphene transfer-layers and UHMWPE transfer film reduces friction and wear loss,while the inclusion of carbon fiber enhances wear resistance due to improved mechanical properties and load bearing capacity.

关键词： friction thermoplastic polyurethane(TPU) water-lubricated bearings graphene platelet carbon fibers ultra-high molecular weight polyethylene(UHMWPE)

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汉字印刷字体的现状及发展趋势

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印刷杂志 2007年第5期 47-49页

作者：原伟民上海印刷技术研究所

作为中国文化事业的重要组成部分，汉字印刷字体具有几千年的历史。汉字印刷字体是形象化的语言，是看得见的思维表达形式。在现代史上，信息交流、传播媒体、大众文化、网络载体、电子文件等等都离不开印刷字体这一现代交流工具。可是... 详细信息

作为中国文化事业的重要组成部分，汉字印刷字体具有几千年的历史。汉字印刷字体是形象化的语言，是看得见的思维表达形式。在现代史上，信息交流、传播媒体、大众文化、网络载体、电子文件等等都离不开印刷字体这一现代交流工具。可是，如果没有印刷字体设计，汉字就会完全失去活力。汉字印刷字体设计得如何，说得大一点，它关系到国家的形象；说得实在一点，它会影响到读者的阅读视觉效果；说得神秘一点，它会影响读者的审美观念。

关键词：汉字印刷字体人才资金市场现状发展趋势

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Single-atom Ag-loaded carbon nitride photocatalysts for efficient degradation of acetaminophen:The role of Ag-atom and O_(2)

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Journal of Environmental Sciences 2024年第5期139卷 12-22页

作者： Yi yuan Wen-Long Wang Zhi-Wei Wang Jin Wang Qian-yuan Wu Key Laboratory of Microorganism Application and Risk Control of Shenzhen Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental SafetyInstitute of Environment and EcologyShenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China Shenzhen Environmental Science and New Energy Technology Engineering Laboratory Tsinghua-Berkeley Shenzhen InstituteShenzhen 518055China College of Materials Science and Engineering Shenzhen UniversityShenzhen 518071China

Carbon nitride has been extensively used as a visible-light photocatalyst,but it has the disadvantages of a low specific surface area,rapid electron-hole recombination,and relatively low light *** this study,single-atom Ag was successfully anchored on ultrathin carbon nitride(UTCN)via thermal polymerization,the catalyst obtained is called *** Ag hardly changed the carbon nitride's layered and porous physical *** exhibited efficient visible-light photocatalytic performances in the degradation of various recalcitrant pollutants,eliminations of 85% were achieved by visible-light irradiation for *** with Ag improved the photocatalytic performance of UTCN by narrowing the forbidden band gap from 2.49 to 2.36 e V and suppressing electron-hole pair *** addition,Ag doping facilitated O_(2) adsorption on UTCN by decreasing the adsorption energy from -0.2 to -2.22 e V and favored the formation of O_(2)^(·-).Electron spin resonance and radical-quenching experiments showed that O_(2)^(·-)was the major reactive species in the degradation of Acetaminophen(paracetamol,APAP).

关键词： Ag single atom Carbon nitride Photocatalysis Visible light Adsorption energy Reactive species

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Impulse Wave Estimation based on Analytic Wavelet in UWB-Radar

Impulse Wave Estimation based on Analytic Wavelet in UWB-Rad...

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第七届国际信号处理会议

作者： Min WANG weimin yuan Shunjun WU (National Key Lab for Radar Signal Processing Xidian Univ. Xi’an China 710071)

A method is discussed in this paper for analysis of received Ultra Wideband pulse in noise based on analytical wavelet transform. Using analytical version of wavelet, the feather of the impulse sha

关键词： analytical wavelet transform UWB impulse noise reduction time delay estimation.

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Outlier item detection in bundle recommendation via the attention mechanism

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High-Confidence Computing 2024年第3期4卷 51-57页

作者： yuan Liang School of Information Engineering Suqian UniversitySuqian 223800China Guangxi Key Laboratory of Trusted Software Guilin University of Electronic TechnologyGuilin 541004China

Bundle recommendation offers users more holistic insights by recommending multiple compatible items at ***,the intricate correlations between items,varied user preferences,and the pronounced data sparsity in combinations present significant challenges for bundle recommendation ***,current bundle recommendation methods fail to identify mismatched items within a given set,a process termed as‘‘outlier item detection’’.These outlier items are those with the weakest correlations within a *** them can aid users in refining their item *** the correlation among items can predict the detection of such outliers,the adaptability of combinations might not be adequately responsive to shifts in individual items during the learning *** limitation can hinder the algorithm’s *** tackle these challenges,we introduce an encoder–decoder architecture tailored for outlier item *** encoder learns potential item correlations through a self-attention ***,the decoder garners efficient inference frameworks by directly assessing item *** have validated the efficacy and efficiency of our proposed algorithm using real-world datasets.

关键词： Bundle recommendation Outlier item detection Attention mechanism Decoder encoder

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浅析印刷字体的专业设计

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印刷杂志 2002年第8期 25-26页

作者：原伟民上海印刷技术研究所

印刷字体(中文)顾名思义即经过排版印刷后反映在出版物上的专业字体.印刷字体的专业设计是为排版印刷业服务的,它是一门比较边沿的学科,属基础研究开发的专业.据笔者所知,在我们中国大陆印刷字体专业设计的队伍也屈指可数,凤毛麟角(目... 详细信息

印刷字体(中文)顾名思义即经过排版印刷后反映在出版物上的专业字体.印刷字体的专业设计是为排版印刷业服务的,它是一门比较边沿的学科,属基础研究开发的专业.据笔者所知,在我们中国大陆印刷字体专业设计的队伍也屈指可数,凤毛麟角(目前仅剩上海印刷技术研究所),堪称'国宝'.它含有哪些技术要素?我想一般没有涉足这一领域的人知道得一定不是很多.

关键词：印刷字体笔形风格字体设计排版

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