检索结果-南通市图书馆

High-precision magnetic field measurement system based on a coherent population trapping magnetometer onboard the SATech-01 satellite

引用

Science China Technological Sciences 2025年

作者： Hongbo XUE Wei SONG Haoran ZHAO Yiteng ZHANG Shanzhi YE Jindong WANG Ran TAO Peng SANG keli chen Xingzi BI Bingjun chenG Bin ZHOU Yongliang XUE Yingying TANG Liu LIU Jinsong LI Xiaocheng ZHU Baoquan LI Jinguo LIU Wen chen Xiaofeng ZHANG Yonghe ZHANG Lei LI State Key Laboratory of Space Weather National Space Science Center Chinese Academy of Sciences Key Laboratory of Solar Activity and Space Weather National Space Science Center Chinese Academy of Sciences Key Laboratory of Electronics and Information Technology for Space Systems National Space Science Center Chinese Academy of Sciences State Key Laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences Innovation Academy for Microsatellites Chinese Academy of Sciences

On July 27, 2022, a high-precision system for measuring the magnetic field based on a coherent population trapping magnetometer（referred to as the CPT system） was launched onboard the Space Advanced Technology demonstration satellite（SATech-01） by a ZK-1A rocket. The payload comprises a scalar coherent population trapping magnetometer（CPTM）, triaxial anisotropic magnetoresistance magnetometer（AMRM）, and nano star tracker mounted on a non-magnetic telescopic tubular mast. This configuration enables synchronized measurement of scalar and vector geomagnetic fields, as well as the attitude,making the payload with its compact sensors suitable for applications on miniature satellite platforms. On November 7, 2022,the novel telescopic tubular mast was deployed in orbit, extending to a length of 5.28 m. The CPTM, an absolute scalar magnetometer with an omnidirectional sensor, is the first China-developed quantum/atomic magnetometer successfully operating in space. In orbit, the CPTM has sensitivity of ～10 pT/Hz1/2and can automatically operate under complex magnetic field variations. The difference between the scalar fields obtained using the CPTM and CHAOS model has a mean deviation of–3.73 n T and a standard deviation of 26.11 nT（1σ）, without on-orbit calibration or correction. The miniaturized AMRM has a sensitivity of ～0.3 n T/Hz1/2and maintains stable and reliable operation in orbit. The low-power and miniaturized nano star tracker has a measurement uncertainty of 14.23″（1σ） in orbit. The mission has realized the on-orbit technical verification of the integrated and synchronized detection of the vector magnetic field and attitude and fully validated the system's performance,automation level, and reliability.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Novel Surface Design of Deployable Reflector Antenna Based on Polar Scissor Structures

引用

Chinese Journal of Mechanical Engineering 2020年第5期33卷 4-18页

作者： Pengyuan Zhao Jinguo Liu chenchen Wu Yangmin Li keli chen State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of ScienceShenyang 110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169China University of Chinese Academy of Sciences Beijing 100049China Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China

Space-deployable mechanisms can be used as supporting structures for large-diameter antennas in space *** study proposes a novel method for constructing the surface design of space reflector antennas based on polar scissor *** concurrency and deployability equations of the space scissor unit with definite surface constraints are derived using the rod and vector *** equations of the spatial transformation for space n-edge polar scissor units are summarized.A new closed-loop deployable structure,called the polar scissor deployable antenna(PSDA),is designed by combining planar polar scissor units with spatial polar scissor *** overconstrained problem is solved by releasing the curve constraint that locates at the end-point of the planar scissor *** simulation and error analysis are *** results show that the PSDA can effectively fit the paraboloid of ***,deployment experiments verify the validity and feasibility of the proposed design method,which provides a new idea for the construction of large space-reflector antennas.

关键词： Deployable structures Polar scissor unit Reflector antenna Surface design

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

Dynamic Analysis and Parametric Optimization of Telescopic Tubular Mast Applied on Solar Sail

引用

Chinese Journal of Mechanical Engineering 2023年第2期36卷 279-290页

作者： chenyang Ji Jinguo Liu chenchen Wu Pengyuan Zhao keli chen State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of ScienceShenyang 110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169China School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China University of Chinese Academy of Sciences Beijing 100049China

Large-scale solar sails can provide power to spacecraft for deep space exploration.A new type of telescopic tubular mast(TTM)driven by a bistable carbon fiber-reinforced polymer tube was designed in this study to solve the problem of contact between the sail membrane and the spacecraft under light *** with the traditional TTM,it has a small size,light weight,high extension ratio,and simple *** anti-blossoming and self-unlocking structure of the proposed TTM was *** aimed to simplify the TTM with a complex structure into a beam model with equal linear mass density,and the simulation results showed good *** dynamic equation was derived based on the equivalent model,and the effects of different factors on the vibration characteristics of the TTM were *** performance parameters were optimized based on a multiobjective genetic algorithm,and prototype production and load experiments were *** results show that the advantages of the new TTM can complete the deployment of large-scale solar sails,which is valuable for future deep space exploration.

关键词： Telescopic tubular mast Solar sail Genetic algorithm Modal analysis Optimization

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

Synthesis, isolation and characterization of methyl levulinate from cellulose catalyzed by extremely low concentration acid

引用

Journal of Energy Chemistry 2013年第6期22卷 895-901页

作者： Hui Li Lincai Peng Lu Lin keli chen Heng Zhang Faculty of Chemical Engineering Kunming University of Science and Technology State Key Laboratory of Pulp and Paper Engineering South China University of Technology School of Energy Research Xiamen University

A direct synthesis of methyl levulinate from cellulose alcoholysis in methanol medium under mild condition(180 210 C)catalyzed by extremely low concentration sulfuric acid(0.01 mol/L)and the product isolation were developed in this *** of different process variables towards the catalytic performance were performed as a function of reaction *** results indicated that sulfuric acid concentration,temperature and initial cellulose concentration had significant effects on the synthesis of methyl *** optimized yield of around 50%was achieved at 210 C for 120 min with sulfuric acid concentration of 0.01 mol/L and initial cellulose concentration below 100 g/*** resulting product mixture was isolated by a distillation technique that combines an atmospheric distillation with a vacuum distillation where n-dodecane was added to help distill the heavy *** light fraction including mainly methanol could be reused as the reaction medium without any substantial change in the yield of methyl *** chemical composition and structural of lower heavy fraction were characterized by GC/MS,FTIR,1H-NMR and13C-NMR *** levulinate was found to be a major ingredient of lower heavy fraction with the content over 96%.This pathway is efficient,environmentally benign and economical for the production of pure levulinate esters from cellulose.

关键词： cellulose methyl levulinate extremely low acid catalysis alcoholysis isolation

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

High flux photocatalytic self-cleaning nanosheet C_(3)N_(4) membrane supported by cellulose nanofibers for dye wastewater purification

引用

Nano Research 2021年第8期14卷 2568-2573页

作者： Lilong Zhang Ge Meng Guifang Fan keli chen Yulong Wu Jian Liu Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China The Key Laboratory of Bionic Engineering(Ministry of Education) Jilin UniversityJilin 130012China Department of Chemistry Tsinghua UniversityBeijing 100084China School of Chemical Engineering and Technology Xinjiang UniversityUrumqi 830046China College of Materials Science and Engineering Qingdao University of Science and Technology Qingdao 266042China

Hazardous dye substances discharged from the textile and dyestuff industries not only threaten local the surrounding ecosystems but are also hard to *** report the preparation of process for a photocatalytic membrane device that can degrade dye pollution under visible *** filtration membrane,with a well-organized multilayer structure,simultaneously achieves continuous and flow-through separation of degradation *** nanofibers(CNFs)were used as a template for nanosheet C_(3)N_(4)(NS C_(3)N_(4))preparation;the performance for the photocatalytic degradation of dyes improved as the morphology changed from bulking to *** C3N4 was then attached to the surface of a prepared CNF membrane via vacuum *** device exhibited high efficiency(the degradation rates of both Rhodamine B and Methylene blue both reached 96%),high flux(above 160 L·h^(-1)·m^(-2)·bar^(-1))and excellent stability(maintaining steady flux and high separation were maintained after 4 h).This easy-preparation,easy-scale-up,and low-cost process provides a new method of fabricating photocatalytic membrane devices for dye wastewater treatment.

关键词： high flux nanofibers nanosheet C_(3)N_(4) photocatalytic membrane dye wastewater

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

1U-Sized Deployable Space Manipulator for Future On-Orbit Servicing,Assembly,and Manufacturing

引用

Space(Science & Technology) 2022年第1期2022卷 500-513页

作者： Jinguo Liu Pengyuan Zhao keli chen Xin Zhang Xiang Zhang State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169China University of Chinese Academy of Sciences Beijing 100049China National Innovation Institute of Defense Technology Academy of Military SciencesBeijingChina

Miniaturized,multifunctional,and economical on-orbit service satellites have been increasingly used with the continuous increase of space exploration *** this paper,an innovative deployable manipulator is designed,named Cubot,which can be stowed in 1 U-sized(10 cm×10 cm×10 cm)*** CubeSat as the carrier,the deployable Cubot aims to achieve a variety of on-orbit operation tasks including space debris removal and space station on-orbit maintenance,for future on-orbit servicing,assembly,and manufacturing(OSAM).A kinematics modeling method of a space manipulator with passive joints is proposed,and the motion equation of the manipulator is *** the elastic potential energy stored in the passive joint during deployment,the momentum change of Cubot is simulated and *** the main forced element,the end effector is analyzed using *** stress response with respect to the force distribution and the clamping angle is analyzed to evaluate mechanical performances of the end-effector *** tests are conducted to verify the feasibility of Cubot based on a principled prototype,which aims to provide engineering and practical experience for the development of this field.

关键词： passive sized Cube

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

MODERN AMERICAN ENGLISH

引用

Chinese Journal of Applied Linguistics 1994年 18卷 181-182页

作者： chen keli Chongqing University of Medical Sciences

With China’s open door policy advocating that Chinese people study abroad, primarily in English-speaking countries, a text tailored to preparing these students is needed. Modern American English, (MAE) composed jointly by Chinese and American linguists, attempts to fill the void. The book’s introduction states a twofold purpose: to help Chinese students learn situational English and to introduce Western culture and society. By assessing MAE’s strength’s and weaknesses it is my intention to provide the publisher with some feedback that may be of some help for forthcoming revisions.

关键词： MODERN AMERICAN ENGLISH

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

有效开展课外阅读的实践探索

引用

教育导刊（上半月） 2005年第8期 45-46页

作者：陈可俪广州市越秀区旧部前小学广东广州510120

运用现代信息技术开展课外阅读,充分发挥课外阅读的育人功能,是学校的办学要求之一.随着基础教育课程改革的不断深入发展,我们对课外阅读进行了更系统、更深入的研究,并使之成为了我校的校本课程,促进了课外阅读的纵深发展.

关键词：课外阅读课程改革图书馆小学语文教学

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

半夏种质资源遗传多样性的SRAP分析

引用

中国中药杂志 2011年第3期36卷 334-337页

作者：杨旻陈科力湖北中医学院省部共建中药资源和中药复方教育部重点实验室湖北武汉430065

目的:利用SRAP标记技术对全国不同产地和表型的半夏居群进行了遗传多样性分析。方法:从80对引物中筛选出14对合适的引物进行半夏不同居群的SRAP分析,用SPSS 16.0软件分析,建立Jaccard相关系数矩阵,构建遗传树系图。结果:14对SRAP引物共... 详细信息

目的:利用SRAP标记技术对全国不同产地和表型的半夏居群进行了遗传多样性分析。方法:从80对引物中筛选出14对合适的引物进行半夏不同居群的SRAP分析,用SPSS 16.0软件分析,建立Jaccard相关系数矩阵,构建遗传树系图。结果:14对SRAP引物共扩增出171条带,多态位点百分率为15.8%,35个半夏居群中表型先于产地聚类在一起。结论:SRAP标记适合于半夏的DNA遗传多样性分析;在半夏种质资源划分上产地较表型更为重要。

关键词：半夏遗传多样性种质资源 SRAP

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

当前中药材市场几种常见假劣药形式

引用

中国中药杂志 2012年第8期37卷 1089-1092页

作者：刘义梅陈科力教育部中药资源和中药复方重点实验室湖北中医药大学药学院湖北武汉430065

尽管中药市场上假劣药的品种较多,但其制假售劣的招法有其共同点。该文依据市场调查和相关文献报道发现当前假劣中药通常以4种形式存在:伪制、伪充品;经过浸提的药材和饮片;掺伪和染色的药材和饮片;生长时间不够或储存过久的药材。通过... 详细信息

尽管中药市场上假劣药的品种较多,但其制假售劣的招法有其共同点。该文依据市场调查和相关文献报道发现当前假劣中药通常以4种形式存在:伪制、伪充品;经过浸提的药材和饮片;掺伪和染色的药材和饮片;生长时间不够或储存过久的药材。通过总结假劣药的各种产生形式及其共同鉴别特点,可以引起警惕并及时检出它们。

关键词：中药材市场中药鉴定假药劣药

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：