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Measurement of ionization distributions at nanometre level in tissue-equivalent gas

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Nuclear Science and Techniques 1998年第2期9卷 92-94页

作者： dang bing-rong Wei Zeng-Quan Li Wen-Jian Li Qiang and Zhang Shu-Min (Institute of Modern Phusics, the Chinese Academy of Sciences, Lanzhou 730000 ) Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China

The developed track detector consists of two parts: a small drift region to obtain a good tracking and a relatively large multiplication region for getting an enough high gain at low pressure. All the track detector can be moved in the direction perpendicular to the beam by means of a micrometric screw. An automatic system allows the counting gas to flow continuously at constant pressure through the detector during the measurements. The system can measure ionization distributions at a few nanometer range.

关键词：放射生物学离子化粒子分布纳米级

QAR Data Imputation Using Generative Adversarial Network with Self-Attention Mechanism

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Big Data Mining and Analytics 2024年第1期7卷 12-28页

作者： Jingqi Zhao Chuitian rong Xin dang Huabo Sun School of Computer Science and Technology Tiangong UniversityTianjin 300387China Institute of Aviation Safety China Academy of Civil Aviation Science and TechnologyBeijing 100028China

Quick Access Recorder(QAR),an important device for storing data from various flight parameters,contains a large amount of valuable data and comprehensively records the real state of the airline ***,the recorded data have certain missing values due to factors,such as weather and equipment *** missing values seriously affect the analysis of QAR data by aeronautical engineers,such as airline flight scenario reproduction and airline flight safety status ***,imputing missing values in the QAR data,which can further guarantee the flight safety of airlines,is *** data also have multivariate,multiprocess,and temporal ***,we innovatively propose the imputation models A-AEGAN("A"denotes attention mechanism,"AE"denotes autoencoder,and"GAN"denotes generative adversarial network)and SA-AEGAN("SA"denotes self-attentive mechanism)for missing values of QAR data,which can be effectively applied to QAR ***,we apply an innovative generative adversarial network to impute missing values from QAR *** improved gated recurrent unit is then introduced as the neural unit of GAN,which can successfully capture the temporal relationships in QAR *** addition,we modify the basic structure of GAN by using an autoencoder as the generator and a recurrent neural network as the *** missing values in the QAR data are imputed by using the adversarial relationship between generator and *** introduce an attention mechanism in the autoencoder to further improve the capability of the proposed model to capture the features of QAR *** mechanisms can maintain the correlation among QAR data and improve the capability of the model to impute missing ***,we improve the proposed model by integrating a self-attention mechanism to further capture the relationship between different parameters within the QAR *** results on real datasets demonstrate that the model can rea

关键词： multivariate time series data imputation self-attention Generative Adversarial Network(GAN)

Low dose effects on cultured mammalian cells...

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Nuclear Science and Techniques 2000年第4期11卷 276-279页

作者： WANG Ju-Fang, LI Wen-Jian, ZHOU Guang-Ming, HE Jing, LI Qiang, dang bing-rong, LI Xing-Lin, XIE Hong-Mei, WEI Zeng-Quan (Institute of Modern Physics, the Chinese Academy of Sciences, Lanzhou 730000) 中科院近代物理所甘肃兰州 730000

The low dose effects induced by carbon ions on Chinese hamster V79 cells and murine melanoma B16 cells were investigated in this paper. Both cell lines were divided into four groups for irradiation: (1) control, (2) 0.02 Gy or 0.05 Gy(D1), (3) 1 Gy(D2), (4) D1+D2. The survivors and micronuclei were studied as biological endpoints. The results of group (1) and group (2) showed that there were no obvious differences on micronucleus frequency but there were significant increases when irradiation dose was 0.02Gy on colony formation efficiency. Although low dose ion irradiation could not contribute to DNA damages, it could enhance the colony formation efficiency. In the study of group (3) and (4), when the ion dose was 0.02 Gy, there were evident increases on surviving fraction and decreases on micronucleus frequency, but there were no statistical changes on these endpoints when the ion dose was 0.05Gy. This meant that high LET radiation could induce the adaptive response of cultured cells, furthermore, in the range of inducing ion dose , low dose irradiation was more profitable than high dose one.

关键词：哺乳动物细胞 DNA 离子辐射低剂量效应辐射效应碳离子

Low-energy-consumption temperature swing system for CO_(2) capture by combining passive radiative cooling and solar heating

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Green Energy & Environment 2024年第3期9卷 507-515页

作者： Ying-Xi dang Peng Tan Bin Hu Chen Gu Xiao-Qin Liu Lin-bing Sun State Key Laboratory of Materials-Oriented Chemical Engineering Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)College of Chemical EngineeringNanjing Tech UniversityNanjing211816China

Temperature-swing adsorption(TSA)is an effective technique for CO_(2) capture,but the temperature swing procedure is ***,we report a low-energy-consumption system by combining passive radiative cooling and solar heating for the uptake of CO_(2) on commercial activated carbons(CACs).During adsorption,the adsorbents are coated with a layer of hierarchically porous poly(vinylidene fluoride-co-hexafluoropropene)[P(VdF-HFP)HP],which cools the adsorbents to a low temperature under sunlight through radiative *** desorption,CACs with broad absorption of the solar spectrum are exposed to light irradiation for *** heating and cooling processes are completely driven by solar *** tests under mimicked sunlight using the CACs show that the performance of this system is comparable to that of the traditional ***,under real sunlight irradiation,the adsorption capacity of the CACs can be well maintained after multiple *** present work may inspire the development of new temperature swing procedures with little energy consumption.

关键词： CO_(2)capture Solar heating Passive radiative cooling Temperature swing adsorption

Effects of alcohol on digestion,absorption and metabolism of sea cucumber saponins in healthy mice

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Food Science and Human Wellness 2024年第1期13卷 137-145页

作者： Wenxian dang rong Li Jinyue Yang Changhu Xue Qingrong Huang Yuming Wang Tiantian Zhang College of Food Science and Engineering Ocean University of ChinaQingdao 266003China Laboratory for Marine Drugs and Bioproducts Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Department of Food Science Rutgers State University New BrunswickNJ 08901USA

Sea cucumber saponins have attracted more attention in recent years due to biological *** is a popular practice to soak sea cucumber in Baijiu at home and being applied to industrial manufacturing in ***,knowledge of the effect of alcohol on the absorption and metabolism of sea cucumber saponins is *** effects of alcohol on digestion,absorption and metabolism of sea cucumber saponins in BALB/c mice were investigated after gavage and tail intravenous *** results showed that the content of saponins in serum and liver was significantly higher under the influence of alcohol than that in the control group after oral *** promoted the absorption of sea cucumber saponins prototype as well as inhibited the process of saponins being transformed into deglycositic metabolites in the small ***,sea cucumber saponins remained in circulation for a long time and alcohol slowed down the clearance of sea cucumber saponins under the influence of alcohol after intravenous *** confirmed the feasibility of marinating sea cucumber in Baijiu to improve the efficacy of saponins and provides an important theoretical basis for the utilization of sea cucumber and the development of sea cucumber liquor.

关键词： Holothurin A Echinoside A Alcohol Absorption Metabolism

Applying Hybrid Clustering in Pulsar Candidate Sifting with Multi-modality for FAST Survey

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Research in Astronomy and Astrophysics 2024年第3期24卷 283-296页

作者： Zi-Yi You Yun-rong Pan Zhi Ma Li Zhang Shuo Xiao Dan-Dan Zhang Shi-Jun dang Ru-Shuang Zhao Pei Wang Ai-Jun Dong Jia-Tao Jiang Ji-bing Leng Wei-An Li Si-Yao Li School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550025China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guizhou Normal UniversityGuiyang 550025China College of Big Data and Information Engineering Guizhou UniversityGuiyang 550025China CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Key Laboratory of Information and Computing Guizhou Province Guizhou Normal UniversityGuiyang 550001China School of Big data and Computer Science Guizhou Normal UniversityGuiyang 550025China Guizhou Software Engineering Research Center Guiyang 550000China

Pulsar search is always the basis of pulsar navigation,gravitational wave detection and other research ***,the volume of pulsar candidates collected by the Five-hundred-meter Aperture Spherical radio Telescope(FAST)shows an explosive growth rate that has brought challenges for its pulsar candidate filtering ***,the multi-view heterogeneous data and class imbalance between true pulsars and non-pulsar candidates have negative effects on traditional single-modal supervised classification *** this study,a multi-modal and semi-supervised learning based on a pulsar candidate sifting algorithm is presented,which adopts a hybrid ensemble clustering scheme of density-based and partition-based methods combined with a feature-level fusion strategy for input data and a data partition strategy for *** on both High Time Resolution Universe SurveyⅡ(HTRU2)and actual FAST observation data demonstrate that the proposed algorithm could excellently identify pulsars:On HTRU2,the precision and recall rates of its parallel mode reach0.981 and 0.988 *** FAST data,those of its parallel mode reach 0.891 and 0.961,meanwhile,the running time also significantly decreases with the increment of parallel nodes within ***,we can conclude that our algorithm could be a feasible idea for large scale pulsar candidate sifting for FAST drift scan observation.

关键词： methods data analysis-surveys-methods numerical

A Review on Flow Boiling of the Fluid with Lower Boiling Point in Micro-Channels

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Journal of Thermal Science 2024年第1期33卷 1-17页

作者： ZHANG Zhiqiang JIA Li dang Chao Beijing Key Laboratory of Flow and Heat Transfer of Phase Changing in Micro and Small Scale School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China

With the advancement of micro machining technology,the high-heat-flux removal from miniature electronic devices and components has become an attractive *** boiling in micro-channels is an optimal form of heat transfer and has been widely employed in high-heat-flux cooling *** comprehensively-reviewed article focused on the available recent literatures of experimental investigation regarding the flow boiling heat transfer and unstable behaviors of the fluid with lower boiling point in *** thermal-fluid characteristics and potential heat transfer mechanisms of low-boiling-point fluids flow boiling in different narrow passages were summarized and *** literatures regarding the pressure drop and occurrence of the unstable phenomena existing in two-phase flow boiling process were also *** emphasis was given to the heat transfer enhancement methods as well as instability elimination,and various methods such as modification of surface and channel flow geometries were *** future researches in the field of micro-scale flow boiling were suggested.

关键词： flow boiling lower boiling point fluids mini/micro-channels instabilities enhancement suppression

Optimal impulsive rendezvous for highly elliptical orbits using linear primer vector theory

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Chinese Journal of Aeronautics 2024年第3期37卷 194-207页

作者： Maozhang ZHENG Jianjun LUO Zhaohui dang National Key Laboratory of Aerospace Flight Dynamics Northwestern Polytechnical UniversityXi’an 710072China

In this paper,minimum-fuel rendezvous is investigated for the case in which the reference orbit is highly *** this end,the well-known Tschauner-Hempel equations are used to describe the relative motions between rendezvous spacecraft and the ***’s primer vector theory is then applied on this linear but time-varying *** analytical solution of the required primer vector for this problem is then derived by using a recently developed *** the existing non-optimal solutions which don’t satisfy the conditions,the methods are further designed to improve the performance by shifting impulses or adding a new ***,two algorithms are developed for free-impulse time-fixed rendezvous *** first algorithm can determine the globally optimal trajectory with the optimal number of *** second one enables for fast trajectory *** proposed algorithms have been successfully applied to coplanar and three-dimensional rendezvous problems in which the target is flying on highly elliptical orbits.

关键词： Orbital transfer Optimal trajectory Primer vector Tschauner-Hempel equations Globally planning Fast planning

Nash-equilibrium strategies of orbital TargetAttacker-Defender game with a non-maneuvering target

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Chinese Journal of Aeronautics 2024年第10期37卷 365-379页

作者： Yifeng LI Xi LIANG Zhaohui dang School of Astronautics Northwestern Polytechnical UniversityXi’an 710072China Beijing Institute of Astronautical Systems Engineering Beijing 100076China

This study investigates the orbital Target-Attacker-Defender(TAD)game problem in the context of space *** this game,the Attacker and the Defender compete for a Target that is unable to maneuver due to its original mission *** paper establishes three TAD game models based on the thrust output capabilities:unconstrained thrust output,thrust constrained by an upper bound,and fixed thrust *** models are then solved using differential game theory to obtain Nash equilibrium solutions for the game problems,and the correctness and effectiveness of the solution methods are verified through ***,an analysis of the winning mechanisms of the game is conducted,identifying key factors that influence the game’s outcomes,including weight coefficients in payoffs,the maximum thrust acceleration limit,and the initial game *** the unique characteristics of space missions,a specific focus is given to the analysis of the Defender’s initial states in the hovering formation and in-plane circling formation,revealing overall success patterns for defense strategies from these two *** summary,this study provides valuable insights into the control strategies and winning mechanisms of orbital TAD games,deepening our understanding of these games and offering practical guidance to improve success rates in real-world scenarios.

关键词： Target-Attacker-Defender problem Differential game TPBVP Continuous thrust Orbital game