检索结果-南通市图书馆

Laser-induced breakdown spectroscopy as a method for millimeter-scale inspection of surface flatness

Plasma Science and Technology 2024年第9期26卷 148-155页

作者： Jinrui YE Yaju LI Zhao ZHANG Xinwei WANG Kewei TAO Qiang ZENG Liangwen CHEN Dongbin QIAN Shaofeng ZHANG Lei YANG xinwen ma Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000People’s Republic of China Advanced Energy Science and Technology Guangdong LaboratoryHuizhou 516000People’s Republic of China University of the Chinese Academy of Sciences Beijing 100049People’s Republic of China Key Laboratory of Atomic and Molecular Physics&Functional materials of Gansu Province College of Physics and Electronic EngineeringNorthwest Normal UniversityLanzhou 730070People’s Republic of China Queen mary University of London Engineering School Northwestern Polytechnical UniversityXi’an 710072People’s Republic of China

A non-contact method for millimeter-scale inspection of material surface flatness via Laser-Induced Breakdown Spectroscopy(LIBS)is investigated *** experiment is performed using a planished surface of an alloy steel sample to simulate its various flatness,ranging from 0 to 4.4 mm,by adjusting the laser focal plane to the surface distance with a step length of 0.2 *** is found that LIBS measurements are successful in inspecting the flatness differences among these simulated cases,implying that the method investigated here is *** is also found that,for achieving the inspection of surface flatness within such a wide range,when univariate analysis is applied,a piecewise calibration model must be *** is due to the complex dependence of plasma formation conditions on the surface flatness,which inevitably complicates the inspection *** solve the problem,a multivariate analysis with the help of Back-Propagation Neural Network(BPNN)algorithms is applied to further construct the calibration *** detailed analysis of the model performance,we demonstrate that a unified calibration model can be well established based on BPNN algorithms for unambiguous millimeter-scale range inspection of surface flatness with a resolution of about 0.2 mm.

关键词： laser-induced breakdown spectroscopy machine learning surface flatness

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Estimating the yield stress of soft materials via laser-induced breakdown spectroscopy

引用

Chinese Physics B 2024年第3期33卷 428-432页

作者：龚书航李亚举钱东斌叶晋瑞赵扣曾强陈良文张少锋杨磊马新文 Advanced Energy Science and Technology Guangdong LaboratoryHuizhou 516000China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

Taking three typical soft samples prepared respectively by loose packings of 77-,95-,and 109-μm copper grains as examples,we perform an experiment to investigate the energy-dependent laser-induced breakdown spectroscopy(LIBS)of soft *** discovered a reversal phenomenon in the trend of energy dependence of plasma emission intensity:increasing initially and then decreasing separated by a well-defined critical *** trend reversal is attributed to the laser-induced recoil pressure at the critical energy just matching the sample's yield *** a result,a one-to-one correspondence can be well established between the samples'yield stress and the critical energy that is easily obtainable from LIBS *** allows us to propose an innovative method for estimating the yield stress of soft materials via LIBS with attractive advantages including in-situ remote detection,real-time data collection,and minimal destructive to sample.

关键词： laser-induced breakdown spectroscopy soft materials yield stress

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Estimating the grain size of microgranular material using laser-induced breakdown spectroscopy combined with machine learning algorithms

引用

Plasma Science and Technology 2024年第5期26卷 129-137页

作者：张朝李亚举杨光辉曾强李小龙陈良文钱东斌孙对兄苏茂根杨磊张少锋马新文 Key Laboratory of Atomic and Molecular Physics and Functional materials of Gansu Province College of Physics and Electronic EngineeringNorthwest Normal UniversityLanzhou 730070People’s Republic of China Advanced Energy Science and Technology Guangdong LaboratoryHuizhou 516000People’s Republic of China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000People’s Republic of China University of the Chinese Academy of Sciences Beijing 100049People’s Republic of China School of Nuclear Science and Technology University of the Chinese Academy of SciencesBeijing 100049People’s Republic of China

Recent work has validated a new method for estimating the grain size of microgranular materials in the range of tens to hundreds of micrometers using laser-induced breakdown spectroscopy(LIBS).In this situation,a piecewise univariate model must be constructed to estimate grain size due to the complex dependence of the plasma formation environment on grain *** the present work,we tentatively construct a unified calibration model suitable for LIBS-based estimation of those grain ***,two unified multivariate calibration models are constructed based on back-propagation neural network(BPNN)algorithms using feature selection strategies with and without considering prior *** detailed analysis of the performances of the two multivariate models,it was found that a unified calibration model can be successfully constructed based on BPNN algorithms for estimating the grain size in the range of tens to hundreds of *** was also found that the model constructed with a priorguided feature selection strategy had better prediction *** study has practical significance in developing the technology for material analysis using LIBS,especially when the LIBS signal exhibits a complex dependence on the material parameter to be estimated.

关键词： laser-induced breakdown spectroscopy machine learning randomly packed microgranular materials

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The n-resolved single-electron capture in slow O^(6+)-Ne collisions

引用

Chinese Physics B 2024年第7期33卷 16-20页

作者：崔述成邢大地朱小龙苏茂根高永郭大龙赵冬梅张少锋符彦飙马新文 Key Laboratory of Atomic and Molecular Physics Functional material of Gansu Province College of Physics and Electronic EngineeringNorthwest Normal UniversityLanzhou 730070China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

A study of single-electron capture(SEC) in 18-240 keV O^(6+)-Ne collisions has been conducted employing a combination of experimental and theoretical *** a reaction microscope,state-selective SEC cross sections and projectile scattering angle distributions were *** translational energy spectra for SEC reveal the prevailing capture into n=3 states of the projectile ion,with a minor contribution from n=4 ***,as the projectile's energy increases,the relative contribution of SEC n=4 states increases while that of SEC n=3 states ***,we computed state-selective relative cross sections and angular differential cross sections employing the classical molecular Coulomb over-the-barrier model(MCBM) and the multichannel Landau-Zener(MCLZ) model.A discernible discrepancy between the state-selective cross sections from the two theoretical models is apparent for the considered impact ***,regarding the angular differential cross sections,an overall agreement was attained between the current experimental results and the theoretical results from the MCLZ model.

关键词： charge exchange state-selective cross sections angular differential cross sections COLTRIMS

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

State-selective charge exchange cross sections in collisions of highly-charged sulfur ions with helium and molecular hydrogen

引用

Chinese Physics B 2024年第2期33卷 29-33页

作者：朱小龙崔述成邢大地徐佳伟 B.Najjari 赵冬梅郭大龙高永张瑞田苏茂根张少锋马新文 Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Atomic and Molecular Physics and Functional materials of Gansu Province College of Physics and Electronic EngineeringNorthwest Normal UniversityLanzhou 730070China Joint Laboratory of Atomic and Molecular Physics Northwest Normal University and Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730070China Advanced Energy Science and Technology Guangdong LaboratoryHuizhou 516000China

The state-selective cross section data are useful for understanding and modeling the x-ray emission in celestial *** the present work,using the cold target recoil ion momentum spectroscopy,for the first time we investigated the state-selective single electron capture processes for S^(q+)–He and H_(2)(q=11–15)collision systems at an impact energy of q×20 keV and obtained the relative state-selective cross *** results indicate that only a few principal quantum states of the projectile energy level are populated in a single electron capture *** particular,the increase of the projectile charge state leads to the population of the states with higher principal quantum *** is also shown that the experimental averaged n-shell populations are reproduced well by the over-barrier *** database is openly available in Science Data Bank at 10.57760/sciencedb.j00113.00091.

关键词： highly charged sulfur ion charge exchange state-selective cross sections COLTRIMS

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

既有建筑加装电梯后结构抗震性能研究

引用

中国电梯 2024年第3期35卷 5-11页

作者：游昊文马新稳司晨旭邓淞文广东省特种设备检测研究院惠州检测院广东惠州516003 西南科技大学土木工程与建筑学院四川绵阳621010

以一栋6层楼高的既有建筑为例,通过ANSYS软件建立3种典型的加装电梯布置方式(E型、I型、H型)的有限元模型,对既有建筑加装电梯后结构进行模态分析,得出加装电梯后结构的自振频率、振型的变化规律。然后,对结构输入不同地震波进行时程分... 详细信息

以一栋6层楼高的既有建筑为例,通过ANSYS软件建立3种典型的加装电梯布置方式(E型、I型、H型)的有限元模型,对既有建筑加装电梯后结构进行模态分析,得出加装电梯后结构的自振频率、振型的变化规律。然后,对结构输入不同地震波进行时程分析,研究不同布置方式、加装电梯连廊与既有建筑不同连接形式对各结构各层加速度峰值、位移峰值的影响。最后,通过频域响应分析探讨了时程分析结果的机理。研究结果表明:采用不同的加装电梯布置方式,加装电梯后结构的自振频率、振型产生的变化不同;采用不同的连接方式,对加装电梯后结构的动力特性、时域响应和频域响应影响较小。

关键词：既有建筑加装电梯抗震性能时域响应频域响应

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The effect of the direct current electric field on the dynamics of the ultracold plasma

引用

Plasma Science and Technology 2018年第8期20卷 6-10页

作者： Syed ZAHEERUDDIN Yufan LI Dongmei ZHAO xinwen ma Jie YANG Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 People' s Republic of China University of Chinese Academy of Sciences Beijing 100049 People's Republic of China

We created an ultracold plasma by photoionizing the laser-cooled and trapped rubidium atoms in a magneto-optical trap. In the externally applied direct current（DC） electric field environment,the electrons which escape from the potential well of the ultracold plasma were detected for different numbers of the ions and initial kinetic energies of the electrons. The results are in good agreement with the calculations, based on the Coulomb potential well model, indicating that the external DC field is an effective tool to adjust the depth of potential well of the plasma, and it is possible to create an ultracold plasma in a controlled manner.

关键词： ultracold plasma magneto-optical trap photoionization Coulomb potential well model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigation of ion-atom collision dynamics through imaging techniques

引用

Science China(Physics,Mechanics & Astronomy) 2008年第7期51卷 755-764页

作者： ma xinwen ZHU XiaoLong LIU HuiPing LI Bin ZHANG ShaoFeng CAO ShiPing FENG WenTian XU ShenYue Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Graduate University of Chinese Academy of Sciences Beijing 100049China

The principle and technique details of recoil ion momentum imaging are discussed and summarized. The recoil ion momentum spectroscopy built at the Institute of Modern Physics (Lanzhou) is presented. The first results obtained at the setup are analyzed. For 30 keV He2+ on He collision, it is found that the capture of single electron occurs dominantly into the first excited states, and the related scattering angle results show that the ground state capture occurs at large impact parameters, while the capture into excited states occurs at small impact parameters. The results manifest the collision dynamics for the sub-femto-second process can be studied through the techniques uniquely. Finally, the future possibilities of applications of the recoil ion momentum spectroscopy in other fields are outlined.

关键词： imaging of recoil ion momentum collision dynamics state-selective cross section angular differential cross section

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dissociation and Coulomb Explosion of in S^(q+)+H_2 Collisions

引用

近代物理研究所和兰州重离子加速器实验室年报：英文版 2003年第1期 96-97页

作者： Wang Zhenglin and ma xinwen

We have investigated fragment emission from molecularions in H2^r+ collisions between S^q+ and H2 with incident energies of 12.5, 15.625, 18.75, 21.875, 25, 28.125, 31.25, 34.375, 37.5, 40.625, and 43.75 keV/u, respectively. The energy distributions of the fragments are measured by time-of-flight techniques. The experimental results show evidences for molecular Coulomb explosion and dissociation. A program[1] is estab-lished based on the Monte Carlo technique to simulate the time-of-flight spectrum of fragment ions with different initialkinetic energy in ion-Molecule collisions. Simulations are done for S^2+ +H2 collisions and compared with experimental results.

关键词：氢气分子离子碰撞散射能量分布硫离子库仑撞击

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

益肺汤调控TGF-β1/Smad2通路抗肺纤维化机制研究

引用

陕西中医 2024年第4期45卷 435-439页

作者：邓祥丽陈丽娟邵梅吴梅杨梅吴海茵马信文黄芬云南中医药大学第一临床医学院云南昆明650051 云南中医药大学第一附属医院云南昆明650021

目的:研究益肺汤含药血清对血管紧张素Ⅱ(AngⅡ)诱导的肺成纤维细胞(NIH-3T3)的影响,探讨其抑制肺纤维化的作用机制。方法:采用SPF级C57小鼠灌胃益肺汤,1次/d,连续给药3 d制备含药血清。实验分为正常对照组、模型组、模型+正常血清组、... 详细信息

目的:研究益肺汤含药血清对血管紧张素Ⅱ(AngⅡ)诱导的肺成纤维细胞(NIH-3T3)的影响,探讨其抑制肺纤维化的作用机制。方法:采用SPF级C57小鼠灌胃益肺汤,1次/d,连续给药3 d制备含药血清。实验分为正常对照组、模型组、模型+正常血清组、模型+含药血清组,给药48 h后0.1%FBS的培养基饥饿处理24 h,100 ng/μl的AngⅡ诱导造模24 h。免疫组化检测α-平滑肌肌动蛋白(α-Sma);免疫荧光检测Smad2;Western blot检测Ⅰ型胶原蛋白(ColⅠ)、α-Sma、纤维连接蛋白(FN)、Smad2;ELISA检测细胞上清转化生长因子-β1(TGF-β1)的表达情况。结果:Western blot和免疫荧光显示,造模后,α-Sma、FN、ColⅠ、Smad2的蛋白相对表达显著升高,差异具有统计学意义(均Pma、FN、Smad2、ColⅠ的相对量较模型组下降(均Pmad2信号通路,降低α-Sma、ColⅠ、FN的表达有关。

关键词：肺纤维化益肺汤 TGF-β1/Smad2信号通路血管紧张素Ⅱ 肺成纤维细胞 α-平滑肌肌动蛋白

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：