双层钙钛矿La_1.8 Ca_1.2 Mn₂ O₇ 磁性相关I-V非线性与电输运性质     

邓恒  杨昌平  黄昌  徐玲芳 《海洋学报》2010,32(10):7390-7395

采用传统固相反应法制备了双层钙钛矿结构锰氧化物La_1.8Ca_1.2Mn₂O₇陶瓷,并用X射线粉末衍射法,扫描电镜,HL5500PC Hall效应分析仪和综合物性测量系统(PPMS)对其磁、电性质进行了表征.结果表明:经过两次高温烧结可合成具有双层Sr₃Ti₂O₇型四方结构的La_1.8Ca_1.2Mn_{2<  相似文献}   

Magnetic hysteresis and refrigeration capacity of Ni—Mn—Ga alloys near Martensitic transformation     

傅斌  龙毅  段静芳  王超伦  常永勤  叶荣昌  吴光恒 《海洋学报(英文版)》2010,29(9)

This paper studies the magnetic hysteresis and refrigeration capacity of Ni--Mn--Ga alloys in detail during heating and cooling isothermal magnetisation processes. The Ni--Mn--Ga alloys show larger magnetic hysteresis when they transform from austenite to martensite, but smaller magnetic hysteresis when they transform from martensite to austenite. This behaviour is independent of either the pure Ni--Mn--Ga alloys or the alloys doped with other elements. Because of the existence of the magnetic hysteresis, the relation between the magnetic entropy change and refrigeration capacity is not simply linear. For practical consideration, magnetocaloric effect of Ni--Mn--Ga alloys should be investigated both on cooling and heating processes.  相似文献   

Distant water fisheries development and vessel monitoring system implementation in Taiwan—History and driving forces   总被引：1，自引：0，他引：1  

Shui-Kai Chang  Kun-Yu Liu  Yann-Huei Song 《Marine Policy》2010

This paper provides an analytical review of the development of distant water fisheries and the implementation of vessel monitoring systems (VMS) in Taiwan. Taiwanese distant water fisheries have gone through several stages in development: rebirth from the damage of World War II up until the early 1970s, stagnation during the mid-1970s to early 1980s, unbridled growth in the late 1980s to a peak in the 1990s–early 2000s, and a stage of disruption and transformation since the mid-2000s. There were two major fisheries in this stage: tuna and squid, both of which rank between the world's first and third largest. Development was mainly driven by national promotion programs and vessel-building restricting policies; and international influences such as oil crises, declaration of exclusive economic zones, and legal arrangements that stimulated strengthening of international management measures. Growth in Taiwan's over-developed fisheries has outpaced the incommensurately scaled Taiwanese fisheries management sector that has not expanded in parallel with the fisheries. Monitoring of vessel activities remains a major management issue. VMS, which can provide both national and international bodies with an essential monitoring capability for ensuring resource management, was found to be one of the important solutions to this issue. The system, however, was initially unacceptable to the fishers, and the government has transformed external pressures arising from international arrangements and management measures into a force for promoting installation of VMS on Taiwanese fishing vessels. This has occurred in stages: a trial period during 1989–1992; initial development during 1994–1996; expansion during 1996–2004; and a more mature stage of enhanced implementation from 2005 to the present.  相似文献   

GPS高程拟合中剔除粗差的方法     

王昶  王旭  王彤 《测绘工程》2009,18(5):55-58,62

在GPS高程拟合中,粗差影响着整个拟合的精度,粗差剔除是GPS高程拟合中重要一步。文中提出一种循环泰勒多项式拟合法和F-T法的组合,通过与部分最小二乘平差法比较,发现这种方法不但有严谨的理论,有可行的应用价值,而且可以有效地剔除粗差。  相似文献   

基于VRML的三维地下管网信息系统的实现     

张小萍  瞿畅  王君泽 《测绘科学》2009,34(4)

针对目前广泛使用的地下管网系统在三维描述方面的欠缺,本文利用虚拟现实技术和VRML语言,构建了基于VRML的三维地下管网信息系统。这一系统的实现,用户可通过网络异地浏览地下管网的三维虚拟模型和查询相关数据信息,大大提高了工作效率和城市数字化管理水平。  相似文献   

An ANN–RTS smoother scheme for accurate INS/GPS integrated attitude determination     

Kai-Wei Chiang  Yung-Cheng Lin  Yun-Wen Huang  Hsiu-Wen Chang 《GPS Solutions》2009,13(3):199-208

Digital mobile mapping, the method that integrates digital imaging with direct geo-referencing, has developed rapidly over the past 15 years. The Kalman filter (KF) is considered an optimal estimation tool for real-time INS/GPS integrated kinematic positioning and orientation determination. However, the accuracy requirements of general mobile mapping applications cannot be easily achieved even when using the KF scheme. Therefore, this study proposes an intelligent scheme combining ANN and RTS backward smoother to overcome the limitations of KF and to enhance the overall accuracy of attitude determination for tactical grade and MEMS INS/GPS integrated systems.

Yun-Wen Huang (Corresponding author)Email:

  相似文献   

基于GIS的宁波市农业资源管理信息系统构建     

黄昌  董浙云  吴健平  杨同辉 《测绘与空间地理信息》2009,32(6):148-150

对在农业资源管理中应用GIS技术的必要性进行了论述,在了解了宁波市农业资源环境的特点以及用户需求的基础上,利用GIS的二次开发技术,对宁波市农业资源管理信息系统进行了构建与开发.  相似文献   

垦利县以体系认证促国土资源管理工作上新水平          下载免费PDF全文

王军  王文元  张吉庆 《山东国土资源》2009,25(2)

2008年垦利县国土资源局在全国县级国土资源管理部门率先引进ISO9001质量管理体系的基础上开展了ISO14001环境管理体系、OHSAS18001职业健康安全管理体系认证。通过三合一质量体系认证工作,努力打造“质量型、环保型、健康型”的国土资源机关,提升国土资源管理服务新形象。  相似文献   

滕州市努力加强地籍管理工作          下载免费PDF全文

常永民  刘冰 《山东国土资源》2009,25(6):50-51

地籍管理工作,是社会各界关注的焦点,涉及广大群众的切身利益。近年来,滕州市国土资源局不断加大地籍管理工作力度,提高工作水平和服务质量,充分发挥地籍信息优势,全面实行“对内以图管地,对外以证管地”工作机制,以产权管理为核心,以基础业务建设为重点,严把土地登记关,使地籍管理工作走上了规范化、制度化的轨道。  相似文献   

对气氡脱气装置改造的几点认识   总被引：2，自引：1，他引：1  

邱鹏成  白占孝  常振广  赵昌军 《地震地磁观测与研究》2007,28(3):85-88

拆除了格尔木井原气氡脱气装置,针对该井冷水、大流量的实际情况,自行设计、制造了一套新的脱气装置,在其后的气氡观测中取得了良好效果,通过对改造前后氡值的分析,充分认识到了合理的脱气装置的重要性,形成了几点新的看法.  相似文献