检索结果-南通市图书馆

The newest observational evidence on asymmetrical deformation of the Earth

Acta Seismologica Sinica(English Edition) 2002年第2期15卷 210-213页

作者：黄立人马宗晋朱建新 First Crustal deformation Monitoring Center China Seismological Bureau Tianjin 300180 China Institute of Geology China Seismological Bureau Beijing 100029 China Department of Mathematics Zhejiang University Hangzhou 310013 China

Based on the coordinates, velocities and their error estimations of 595 GPS, SLR and VLBI stations issued by IERS in March 2001, the current asymmetrical deformation of the Earth is studied. The results show that the northern hemisphere of the Earth is undergoing compressive deformation, and the southern hemisphere is undergoing extensional deformation with the equator as the boundary. If the longitude line of 90°E and 90°W is taken as the boundary, the Pacific hemisphere (with 180° as its central longitude) is undergoing compressive deformation, and the Atlantic hemisphere (with 0° as its central longitude) is undergoing extensional deformation. The deformation patterns indicate again that the Earth is undergoing some dual-asymmetrical deformation. Moreover, taking 6 366.740 km as the standard mean curvature radius of the Earth, the velocity of volume change calculated from the data of space geodesy is 6.65x10-(11)m3/a.

关键词： asymmetrical deformation Earth space geodesy

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

A Novel Fabrication for Method Long PeriodFiber Grating

引用

Chinese Journal of Lasers 2002年第2期11卷 39-42页

作者： HE Shuo LI Xinwan YE Ailun HE Wanxun SONG Hao(State Key Laboratory on Local Fiber Communication Networks andAdvanced Fiber Communication Systems, Optical Fiber Technology Institute,Shanghai Jiaotong University, Shanghai 200030, China) Optical Fiber Technology Institute Shanghai Jiaotong University State Key Laboratory on Local Fiber Communication Networks and Advanced Fiber Communication Systems 上海 200030

A new method of fabricating all-fiber broadband-rejection filter based on long period fiber grating (LPFG) is proposed. The principle in the method is to make periodic asymmetrical deformation in the core of fiber without microbends by electrode discharging so as to induce periodic refractive index changes. Two kinds of filters whose rejection peak wavelength at 1550 nm and 1310 nm are obtained. The insertion loss is less than 0.6 dB and 1.4 dB respectively. The 20 dB bandwidth ranges from 10 nm to 39 nm. The backward reflection loss is extremely small (less than - 70 dB). Such devices can be used as isolation filters in 1310/1550 nm WDM system and other fields.

关键词： long period fiber grating band-rejection filter asymmetrical deformation

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

Study on the Earth’s volume change by using space observed technology

Study on the Earth’s volume change by using space observed ...

引用

第四届中国卫星导航学术年会

作者： Xinhui Zhu Fuping Sun Ren Wang Information and Engineering University Navigation and Aerospace Engineering Institute

Although plate tectonics already being the studying basis and mainstream of global tectonics nowadays, theories of expanding or compressing about the Earth have not been ceased in deed, which were still the main objects of investigating and searching proofs for many geoscientists. In the research of plate tectonics, a basic hypothesis which has been used until now is that the solid Earth’s volume （or radius） keeps unchanging because the lithosphere’s expanding and compressing could be compensated mutually. Whether and in which time scale these hypothesizes is correct or not, that has not been proved rigorously. Along with the development of space techniques and improvement of geodetic precision, it is possible to detect and resolve above problems in the help of more and higher precision observations and stations distributing globally. The earth’s unsymmetrical phenomenon and the doctrine of its expansion and compression was discussed and expounded. After a detailed analysis of the status of global change phenomena research, one data processing method by unifying the global vertical velocity to the optimal global crustal vertical motion reference datum was put forward. Then the solid earth’s volume and radius change were detected by using Delaunay arithmetic and plate motion model interpolation method. The result shows that the earth volume’s change rate is （-0.0379±0.0902）×103km3/a, which is similar to （-0.1±0.2）mm/a after being converted to the change of the earth’s radius, and is close to the result （near to -0.24mm/a） by using global observed station’s radial velocity. The conclusion is that the radius of the earth cannot be considered changed in the range of one time mean error, which is corresponded to the results of others by using space observed data and physical geography information.

关键词： Space-geodetic data Earth asymmetrical deformation Delaunay triangle gridding Reference datum of global vertical crustal motion

来源： cnki会议评论

在线全文

cnki会议

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

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

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：