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Ultrahigh spatiotemporal resolved spectroscopy

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Science China(Physics,Mechanics & Astronomy) 2007年第6期50卷 681-690页

作者： LI Zhi,ZHANG JiaSen,YANG Jing & GONG QiHuang Department of Physics and State Key Laboratory for Mesoscopic Physics,Peking University,Beijing 100871,China Department of Physics and State Key Laboratory for Mesoscopic Physics Peking University Beijing China

We review the technique and research of the ultrahigh spatiotemporal resolved spectroscopy and its applications in the field of the ultrafast dynamics of mesoscopic systems and nanomaterials. Combining femtosecond time-resolved spectroscopy and scanning near-field optical microscopy (SNOM),we can obtain the spectra with ultrahigh temporal and spatial resolutions simultaneously. Some problems in doing so are discussed. Then we show the important applications of the ultrahigh spatiotemporal resolved spectroscopy with a few typical examples.

关键词： ultrahigh spatiotemporal resolved spectroscopy, femtosecond near-field spectroscopy, scanning near-field optical microscopy (SNOM), femtosecond time-resolved, nanomaterial We review the technique and research of the ultrahigh spatiotemporal resolved spectroscopy and its applications in the field of the ultrafast dynamics of mesoscopic systems and nanomaterials. Combining femtosecond time-resolved spectroscopy and scanning near-field optical microscopy (SNOM), we can obtain the spectra with ultrahigh temporal and spatial resolutions simultaneously. Some problems in doing so are discussed. Then we show the important applications of the ultrahigh spatiotemporal resolved spectroscopy with a few typical examples.……

Generation of 7-fs laser pulse directly from a compact Ti:sapphire laser with chirped mirrors

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Science China(Physics,Mechanics & Astronomy) 2007年第3期50卷 261-266页

作者： ZHAO YanYing WANG Peng ZHANG Wei TIAN JinRong WEI ZhiYi Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100080China College of Applied Science Beijing University of TechnologyBeijing 100022China

A compact femtosecond Ti:sapphire laser resonator consisting of three chirped mirrors and one output coupler was designed. By accurately balancing the intra- cavity dispersions between Ti:sapphire crystal, air and chirped mirrors, we directly generated the laser pulse shorter than 7 fs at the average power of 340 mW with 3.1 W pump. The repetition rate of the laser oscillator is 173 MHz at the centre wavelength of 791 nm, and the ultrabroaden spectrum covers from 600 nm to 1000 nm. To the best of our knowledge, this is the simplest laser resonator capable of generating sub-10 fs laser pulse.

关键词： Ti:sapphire laser chirped mirror femtosecond few cycles pulse

Numerical study of point spread function of a fast neutron radiography system based on scintillating-fiber array

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Science China(Physics,Mechanics & Astronomy) 2007年第6期50卷 698-706页

作者： ZHANG FaQiang1,LI ZhengHong1,YANG JianLun1,YE Fan1,2,WANG Zhen1,2,XIA GuangXin1,YING ChunTong2 & LIU GuangJun2 1 Institute of Nuclear Physics and Chemistry,Mianyang 621900,China 2 Department of Engineering Physics,Tsinghua University,Beijing 100084,China Institute of Nuclear Physics and Chemistry Mianyang China Department of Engineering Physics Tsinghua University Beijing China

For a scintillating-fiber array fast-neutron radiography system,a point-spread-function computing model was introduced,and the simulation code was developed. The results of calculation show that fast-neutron radiographs vary with the size of fast neutron sources,the size of fiber cross-section and the imaging geometry. The results suggest that the following qualifications are helpful for a good point spread function: The cross-section of scintillating fibers not greater than 200 μm×200 μm,the size of neutron source as small as a few millimeters,the distance between the source and the scintillating fiber array greater than 1 m,and inspected samples placed as close as possible to the array. The results give suggestions not only to experiment considerations but also to the estimation of spatial resolution for a specific system.

关键词： fast neutron radiography, scintillating-fiber array, point spread function, Monte Carlo simulation For a scintillating-fiber array fast-neutron radiography system, a point-spread- function computing model was introduced, and the simulation code was developed. The results of calculation show that fast-neutron radiographs vary with the size of fast neutron sources, the size of fiber cross-section and the imaging geometry. The results suggest that the following qualifications are helpful for a good point spread function: The cross-section of scintillating fibers not greater than 200μm×200μm, the size of neutron source as small as a few millimeters, the distance between the source and the scintillating fiber array greater than 1 m, and inspected samples placed as close as possible to the array. The results give suggestions not only to experiment considerations but also to the estimation of spatial resolution for a specific system.……

Dynamical Structure of A≤4 Hypernuclei and Charge Symmetry Breaking

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Chinese journal of nuclear physics 1994年第2期16卷 139-145页

作者： Luo Bin Kong Fanxin Liu Xianhui(Center of Theoretical Physics CCA ST( World Lab.),Beijing 100080)(Institute of High Energy Physics,Academia Sinica,Beijing 100039) Guangxi Teacher’s University,Guilin,541001. 中科院高能物理所北京 100039 中科院高能物理所北京

-The dynamical structure of A≤4 Λ-hypernuclei is studied by using thefew-body theoretical method.The AN interaction is taken to be the meson exchange po-tential with the single k,ω,η exchange diagrams and the box diagrams of π and πρ ex-change containing the intermediate state particles Σ,Δ.The Λ binding energy differenceof the mirror hypernuclei _Λ~4He and _Λ~4H is explained.It is shown that the root meansquare distances between the particles in the light hypernuclei are almost the same andthere does not exist any nuclear core.The relative motion between particles stay mainlyin 1S state.

关键词： Hypernuclei few body Meson exchange

ICRP PUBLICATION 60 HOW MUCH SCIENCE, HOW MUCH JUDGEMENT? REFLECTIONS ON A few DIFFERENT ISSUES

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辐射防护 1998年第Z1期18卷 13-19页

作者： Charles Meinhold(National Council on Radiation Protection and Measurements,USA) National Council on Radiation Protection and Measurements 美国

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ＡｎｉｍｐｏｒｔａｎｔｏｂｊｅｃｔｉｖｅｏｆｔｈｅＣｏｍｍｉｓｉｏｎｉｓｔｈｅｐｒｏｖｉｓｉｏｎｏｆｓｃｉｅｎｔｉｆｉｃａｌｙｂａｓｅｄｒｅｃｏｍｍｅｎｄａｔｉｏｎｓｔｈａｔｍｅｒｉｔｗｉｄｅｓｐｒｅａｄａｃｅｐｔａｎｃｅ．Ｉｎｔｏｄａｙｓｓｈｒｉ...

关键词： ICRP PUBLICATION HOW MUCH ISSUES DIFFERENT few

IGEO野外考察视域下高中生地理实践力的培养策略研究——以“渭河流域”三地考察为例

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IGEO野外考察视域下高中生地理实践力的培养策略研究——以“渭河...

作者：杨金轮西南大学

学位级别：硕士

《普通高中地理课程标准(2017年版)》中凝练了地理学科核心素养,地理实践力作为地理核心素养的重要组成部分,被越来越多的地理学者所关注。培养地理实践力主要的方法之一是野外考察教学,因此野外考察成为地理教育者热议的一个话题。但... 详细信息

《普通高中地理课程标准(2017年版)》中凝练了地理学科核心素养,地理实践力作为地理核心素养的重要组成部分,被越来越多的地理学者所关注。培养地理实践力主要的方法之一是野外考察教学,因此野外考察成为地理教育者热议的一个话题。但是通过问卷调查我们发现,各中学在培养地理实践力方面存在种种困难,因此关于如何更好的落实高中生地理实践力培养的研究就显得很重要。国际地理奥林匹克竞赛(简称IGEO)代表了世界地理教育发展的总体趋势,研究IGEO野外考察(few)有利于把握地理国际教育总趋势,有利于为课改提供新思路,有利于促进高中生地理实践力的培养,有利于提高教学质量。因此本文以IGEO野外考察练习模块(few)为研究对象,结合中国野外考察实践教学的实际状况,开展关于IGEO野外考察视域下培养高中生地理实践力的策略研究。笔者通过文献研究法对IGEO、few、地理实践力等概念进行鉴定,重点阐述了野外考察与地理核心素养的培养目的虽然高度一致,但是few要求学生在真实复杂的情境中,需要运用地理实践力的高阶能力去考察区域环境。通过统计分析法、归纳法和比较法对few的试题指南、试题设计、试题内容、考察能力、评价标准五个方面进行详细分析。笔者得知few的试题指南可以让学生提前明确考察的形式、内容、计分标准(评价标准),便于学生收集资料,剖析考察内容。few考察形式采取“野外考察+室内分析”的方式,考查学生观察、获取信息、读图和绘图技能、分析和解决问题的能力。few答题方式包括个人和小组合作两种方式,不仅考察学生的合作素养,还考察个人参与的实际能力。试题结构方面,few需要明确活动主题、评分标准和活动时间等内容。few信息呈现多以图文表融合的形式,对学生综合思维能力的要求较高。few试题内容多样化,12个地理主题几乎涵盖了普通高中地理学科全部内容,且在广度和深度上有一定的拓展,有部分涉及到高等地理教育的内容。few考察能力要求高于《普通高中地理课程标准(2017年版)》中提出的地理实践力水平标准。few评分标准方面与few试题需要测试的行为目标要求基本一致;评分标准的结构模式合理,配有参考答案和评分细则及说明;开放性试题呈现学生可能回答的所有正确答案。依靠对few的全面研究,再结合问卷调查的分析结果,笔者提出培养高中生地理实践力在实施形式上采取练习与考试相结合,室内与室外相结合,独立与小组合作完成相结合,校内组织与校外合作相结合,自主与强制参与相结合的方式。在实施途径上可以采取户外考察、研究性学习、研学和旅行的方式。野外考察可以设置“活动前制定活动指南→活动中野外实践→活动后室内分析”的实施步骤。内容选择的渠道可参考国际地理教育宪章与新地理课程标准,依据当地的地理环境特点。内容选择的标准主要是新地理课程标准和地理教育国际宪章相结合,主题化和内容多样化,实践性和情境性。评价设计需要探索合理的评分模式,评价方式多元化;评价标准与实践目标相结合;构建科学的评价指标体系;及时反馈考察结果。最后,笔者结合自己的实践调查经验,设计了三个IGEO野外考察视域下高中生地理实践力培养的案例以及对案例实施获得的实践效果说明和启示。

关键词：地理实践力 IGEO 野外考察 few

结果状语从句so...that.../such...that.../so that的用法区别

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初中生辅导 2023年第17期 31-33页

作者：杨娟贵州省黔东南苗族侗族自治州岑巩县第四中学

一、定义简介在句子中,充当结果状语的句子称为结果状语从句,通常位于主句之后。常用so...that.../such...that.../so that等来引导,表示“如此……以至于……”,that后接的句子表示主句动作所导致的结果。其规律由so与such的不同词性... 详细信息

一、定义简介在句子中,充当结果状语的句子称为结果状语从句,通常位于主句之后。常用so...that.../such...that.../so that等来引导,表示“如此……以至于……”,that后接的句子表示主句动作所导致的结果。其规律由so与such的不同词性决定。so是副词,只能修饰形容词或副词,so还可以与表示数量的形容词many,few,much,little连用;such是形容词,修饰名词或名词词组。

关键词：名词词组 such 修饰名词用法区别 many little 形容词 few

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你想跟little和few交朋友吗?

中学生英语 2007年第5期 6-6页

作者：靳青湖北省宜昌市一中

little,few可是本单元的重点哟!想弄清它们的用法,可要好好掌握以下表格。

关键词：不可数名词交朋友 few little

The Risk of Water, Energy, and Food Nexus under Regional Metabolism for Multi-Sector City

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Journal of Environmental Protection 2020年第10期11卷 909-920页

作者： I-Chun Chen Department of Land Resources Chinese Culture University Taiwan

The Urban Nexus system creates another risk characteristic of resource metabolism. Urban metabolism has complex effects from multi-levels and multi-sectors resulted from the changes socio-economic. It is crucial to implement effective urban governance;in particular, resource metabolism creates a new nexus risk by dramatic growth in urban areas. The resource metabolism associates with water, energy, and food consumption on an urban scale that drives the intensity in resource metabolism. Therefore, this study estimates the few intensity of the nexus and demand side in material flow analysis by organizing into four categories of resource metabolism, including supply side, process side, demand side, and final sink. This research compares different characteristics for a small island dominated by tourism and a multi-sector city dominated by increasing economic activity. The resource intensity on the demand side and resource service systems are evaluated to identify the nexus intensity and risk for few nexus at the urban scale. This study determines that constraints for resource service systems are complex, and suggests that resource consumption intensity is higher in that particular nexus and demand sector. To avoid excessive loads on resource metabolism, sustainable resource management should implement trade-off strategies after analyzing the resource metabolism for urban nexus.

关键词： Nexus Risk few Resource Metabolism Multi-Sector City