检索结果-南通市图书馆

Highly efficientγ-ray generation by 10 PW-class lasers irradiating heavy-ion plasmas

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2022年第7期24卷 201-207页

作者： mi tian Ziyu CHEN Key Laboratory of High Energy Density Physics and Technology(MoE) College of PhysicsSichuan UniversityChengdu 610064People's Republic of China National Key Laboratory of Shock Wave and Detonation Physics Mianyang 621999People's Republic of China

10 PW-class lasers irradiating overcritical plasmas in the quantum electrodynamics regime promise to generate ultrabrightγ-ray sources in the *** using two-dimensional particle-in-cell simulations,we report highly efficientγ-ray generation in the parameter regime of 10 PW-class lasers at an intensity level of 10^(23)W cm^(–2)interaction with heavy-ion plasmas which have large-scale *** laser-to-γ-ray(>1 MeV)energy conversion efficiency reaches close to 60%with an above 10^(14)γ-photons/*** averageγ-photon energy is about 14 MeV with the highest photon energy exceeding 1 *** high-energyγ-photons are mainly directed in the forward *** also find that plane target geometry is efficient enough for high powerγ-ray radiation,which is beneficial for easing the difficulty of complex target manufacturing and alignment in experiments.

关键词： laser plasma interactions γ-ray source particle-in-cell simulations

在线全文

学校读者我要写书评

暂无评论

基于基因组重测序的沉香遗传多样性研究

热带作物学报 2025年第1期46卷 51-58页

作者：苟志辉陈国德甄云楠王鑫陈彧田蜜海南省林业科学研究院(海南省红树林研究院) 海南海口571100 海南省热带林业资源监测与应用重点实验室海南海口571100 海口市湿地保护管理中心海南海口571100

对种质资源信息的掌握是土沉香遗传改良的基础,而基因组重测序是种质资源遗传多样性分析的利器,然而目前学术界缺乏利用基因组重测序对土沉香遗传多样性的研究。本研究在前期收集得到的沉香种质资源基础上,采用基因组重测序,获得60份沉... 详细信息

对种质资源信息的掌握是土沉香遗传改良的基础,而基因组重测序是种质资源遗传多样性分析的利器,然而目前学术界缺乏利用基因组重测序对土沉香遗传多样性的研究。本研究在前期收集得到的沉香种质资源基础上,采用基因组重测序,获得60份沉香共1284 Gb重测序数据。利用沉香基因组,共检测得到6 713 166个高质量变异位点,其中SNP位点6 284 344个,Indel位点428 658个。主成分分析、系统发育分析和遗传结构分析均表明,沉香可分为3个显著群体(Pop1、Pop2和Pop3),其中2个群体可分别进一步划分为多个亚群。在3个群体中均检测到群体选择信号,其中Pop3选择信号最多,而核苷酸多态性计算结果表明,Pop3的核苷酸多态性最低。本研究为探究沉香遗传资源多样性提供了有价值的信息,并为基于基因组的沉香遗传育种奠定理论基础。

关键词：沉香基因组重测序变异位点遗传多样性

Tectonic evolution of the Dabashan orocline, central China: Insights from the superposed folds in the eastern Dabashan foreland

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2013年第6期4卷 729-741页

作者： Wei Shi Jianhua Li mi tian Guoli Wu Key Laboratory of Neotectonic Movement and Geohazard Ministry of Land and Resources Institute of Geomechanics Chinese Academy of Geological Sciences Wuxi Research Institute of Petroleum Geology Institute of Geology and Geophysics Chinese Academy of Sciences

The Dabashan orocline is situated in the northwestern margin of the central Yangtze block,central *** studies have defined the orthogonal superposed folds growing in its central-western segment thereby confirming its two-stage tectonic evolution *** mapping has revealed that more types of superposed folds have developed in the eastern segment of the orocline,which probably provides more clues for probing the structure and tectonic history of the Dabashan *** this paper,based on geological mapping,structural measurements and analyses of deformation,we have identified three groups of folds with different trends （***-,NE-and nearly E-trending folds） and three types of structural patterns of superposed folds in the eastern Dabashan foreland （***-axial,oblique,and conjunctional superposed folds）.In combination with geochronological data,we propose that the synaxial superposed folds are due to two stages of ～N-S shortening in the west and north of the Shennongjia massif,and that oblique superposed folds have been resulted from the superposition of the NW-and NE-trending folds onto the early ～ E-W folds in the east of the Shennongjia massif in the late Jurassic to early *** conjunctional folds are composed of the NW-and NE-trending folds,corresponding to the regional-scale dual-orocline in the eastern Sichuan as a result of the southwestward expansion of the Dabashan foreland during late Jurassic to early Cretaceous,coeval with the northwestward propagation of the Xuefengshan *** of the structure and geochronology of the belt shows that the Dabashan orocline is a combined deformation belt primarily experiencing a twostage tectonic evolution history in Mesozoic,initiation of the Dabashan orocline as a foreland basin along the front of the Qinling orogen in late Triassic to early Jurassic due to collisional orogeny,and the final formation of the Dabashan orocline owing to the southwestward propagation of th

关键词： Dabashan foreland belt Superposed folds Orocline Paleo-stress field Intra-continental orogeny Late Jurassic

Mechanism in Solidification of a Ternary Nickel Based Alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 1018-1024页

作者：田密成博 School of Aeronautical Manufacturing Industry Chengdu Aeronautical PolytechnicChengdu 610100China College of Mechanical Engineering North University of ChinaTaiyuan 030051China

The experiment employed the use of melt purification and cyclic superheating technique to achieve maximum undercooling of Ni65Cu31Co4 alloy at ***,high-speed photography techniques were used to capture the process of alloy liquid phase interface migration,and analyzed the relationship between the shape characteristics of the front end of alloy solidification and *** microstructure of the alloy was observed through metallographic microscopy,and the micro-morphological characteristics and evolution of the rapidly solidified microstructure were systematically *** is found that the grain refinement mechanism of Ni-Cu-Co ternary alloy is similar to that of Ni-Cu binary *** refinement at low undercooling is caused by intense dendritic remelting,while grain refinement at high undercooling is attributed to recrystallization,driven by the stress and plastic strain accumulated from the interaction of liquid flow and primary dendrites caused by rapid *** also shows that the addition of the third element Co plays a significant role in solidification rate and re-ignition effect.

关键词： undercooling recalescence Ni-Cu-Co ternary alloy grain refinement recrystallization

Preparation and electrocatalytic property of Au-Pt/SnO_2/GC composite electrode

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2009年第4期28卷 350-354页

作者： YU Zhihui XIE Jia BAI Jie tian mi XIA Dingguo College of Environmental and Energy Engineering Beijing University of Technology Beijing 100124 China

Au-Pt/SnO2/GC composite electrode was prepared by self-assembling Au-Pt nanoparticles on SnO2 film, which was deposited on actived glassy carbon （GC）. Atomic force microscopy （AFM） and scanning electron microscopy （SEM） images revealed that dense and uniform Au-Pt particles with 25-nm diameter were dispersed on SnO2 film. X-ray photoelectron spectroscopy （XPS） results proved that there was an interaction between Au-Pt nanoparticles and SnO2 support. Electrochemical experiments showed that Au-Pt/SnOz/GC composite electrode had a good electrocatalytic activity to the oxidation of methanol

关键词： . electrochemistry composite electrode self-assembling Au-Pt SnO2 methanol oxidation

Characteristics of Clustering Debris Flows in Wenchuan Earthquake Zone

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2013年第6期10卷 953-961页

作者： MA Chao HU Kai-heng ZOU Qiang tian mi Key Laboratory of Mountain Hazards and Earth Surface Processes Chinese Academy of Sciences Institute of Mountain Hazards and Environment Chinese Academy of Sciences Graduate school of Chinese Academy of Science

Clustering debris-flow events, namely many debris flows simultaneously triggered by a regional rainstorm in a large-scale mountainous area,occurred in four regions of Wenchuan earthquake stricken areas in 2008 and 2010. The characteristics of the clustering debris flows are examined with regard to triggering rainfall, formation process, and relationship with the earthquake by field survey and remote sensing interpretation. It is found that the clustering events occurred nearly at the same time with the local peak rainstorms, and the rainfall intensity-duration bottom limit line for clustering debris flows is higher than the worldwide line. It means that more rainfall is needed for the occurrence of the clustering debris flows. Four kinds of major formation processes for these debris flows are summarized: tributary-dominated, mainstreamdominated, transformation from slope failures, and mobilization or liquefaction of landslide. The four regions has a spatial correlation with the strongquake-influenced zone with the peak ground acceleration = 0.2 g and the seismic intensity > X.

关键词： Clustering debris flows Wenchuanearthquake Rainfall threshold Formation process

A new flavone glycoside from Selaginella moellendorffii Hieron.

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2008年第12期19卷 1456-1458页

作者： tian mi Zhu Ke Li Chen Wen Bing Zhou Key Laboratory of Traditional Chinese Medicine Resource and Compound Prescription Ministry of Education Hubei College of Traditional Chinese Medicine Wuhan 430065 China

From the ethanol extract of Selaginella moellendorffii Hieron., a new flavone O-glycoside and three known flavone C-glycosides have been isolated and identified as 5-carboxymethyl-4′-hydroxyflavone-7-O-β-D-glucopyranoside 1, 6,8-di-C-β-D-glueopyranosylapigenin 2, 6-C-[3-D-glucopyranosyl-8-C-β-D-xylopyranosyl apigenin 3, 6-C-B-D-xylopyranosyl-8-C-β-glucopyranosylapigenin 4, respectively. Their structures were elucidated by spectroscopic methods.

关键词： SelagineUa moellendorf-fii 5-Carboxymethyl-4-hydroxyflavone-7-O-β-D-glucopyranoside New flavone glycoside

Formation of the Moping Dome in the Xuefengshan Orocline, Central China and its Tectonic Significance

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2013年第3期87卷 720-729页

作者： SHI Wei DONG Shuwen LI Jianhua tian mi WU Guoli Institute of Geomechanics Chinese Academy of Geological Sciences Key Laboratory of Neotectonic Movement and Geohazard Ministry of Land and Resources Chinese Academy of Geological Sciences Wuxi Research Institute of Petroleum Geology SINOPEC Institute of Geology and Geophysics Chinese Academy of Sciences

Many equiaxial dome-like structures developed in the north segment of the Xuefengshan orocline, Central China are obviously inconcordant with the NE-trending linear structures in this area, which contain important records for understanding the structural framework and evolution of this belt. In this paper, taking one of the typical dome-like structures in the Xuefengshan orcline （e.g. Moping dome-like structure） as an example, based on its structural framework interpratatoin, superposed deformation analysis and paleo-stress fields reconstruction, we propose the Moping dome- like structure is composed of two populations of different-striking thrust-fold structures, -E-trending and NE-striking structures, indicative of two-stages shortening, -N- and NW-striking, respectively. Together with the geochronological analysis, we suggest the first stage of shortening occurred in Late Triassic to Early Jurassic, due to the Indosinian intercollisional orogeny of the Yangtze Block and the North China Block. The second occurred during Late Jurassic-Early Cretaceous owing to Yanshanian intracontinental orogeny, leading to the intensive superposition of the NE-trending structures onto the -E-trending structures, and the final ocurrence of the Moping dome. Thus, our study indicates the Xuefengshan arc-shape belt also experienced two-phase deformation, and resulted from the superposition of NE-SW structures onto -E-W structures in Late Jurassic-Early Cretaceous, which could provide new structural evidence for probing the Mesozoic tectonic framework and evolution of the Xuefengshan orocline.

关键词： Xuefengshan orocline Moping dome superposed structure paleo-stress field intracontinental orogeny

Photoelectrochemistry of electrochemically deposited cadmium-rich cadmium mercury telluride films

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 1991年第1期9卷 40-44页

作者： TAN Zheng LI Jun mi tian-Ying Changchun Institute of Applied Chemistry Academia SinicaChangchun 130022

The potentiostatic deposition of cadmium-rich CMT films onto Ti, Mo, Ni substrates from an aqueous bath was carried out. The photoelectrochemical properties of film electrodes were investigated when used in a solid-li... 详细信息

关键词： Photoelectrochemistry of electrochemically deposited cadmium-rich cadmium mercury telluride films