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低感应数条件下大地电导率测量方法研究 被引量:5
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作者 许诚 白登海 丁艳飞 《地球物理学进展》 CSCD 北大核心 2010年第4期1372-1379,共8页
本文论述一种测量大地电导率的电磁感应方法.通有交变电流的磁偶极子会在大地中产生一次磁场和二次磁场.在低感应数的条件下,大地电导率与一次磁场和二次磁场的比值是一种简单的线性关系.利用这种关系,我们就可以直接获取地下大地视电导... 本文论述一种测量大地电导率的电磁感应方法.通有交变电流的磁偶极子会在大地中产生一次磁场和二次磁场.在低感应数的条件下,大地电导率与一次磁场和二次磁场的比值是一种简单的线性关系.利用这种关系,我们就可以直接获取地下大地视电导率.文章还论述了引出了积累响应函数和相对响应函数,给出一种简单的数据解释方法. 展开更多
关键词 感应 大地电导率 积累响应函 相对响应函
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基于频域有限差分的三维大地电磁的低感应数预条件求解方法研究 被引量:3
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作者 蒋涛 胡文宝 《石油天然气学报》 CAS CSCD 2014年第9期88-93,6,共6页
求解Maxwell微分方程经过离散后得到的大型、病态线性方程组的高机时制约了为电磁数据反演而进行的三维正演算法的应用。一种新的基于电场的Helmholtz分解的低感应数预条件可以解决该问题。通过对一个三维埋藏体进行有限差分正演,分析... 求解Maxwell微分方程经过离散后得到的大型、病态线性方程组的高机时制约了为电磁数据反演而进行的三维正演算法的应用。一种新的基于电场的Helmholtz分解的低感应数预条件可以解决该问题。通过对一个三维埋藏体进行有限差分正演,分析比较了低感应数预条件迭代求解过程中2种算法(共轭梯度法、最小残差法)的迭代次数与时间,结果表明,采用最小残差法构建低感应数预条件矩阵,线性方程组的迭代求解次数和和求解时间都要比共轭梯度法少,具有一定的速度优势。 展开更多
关键词 频域有限差分 正演 预条件 Helmholtz分解 感应
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产甲酸草酸杆菌细胞数群体感应系统基因hdtS克隆和功能分析
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作者 姜巨全 刘贺男 +2 位作者 肖鸿禹 付晓薇 朱光宇 《东北农业大学学报》 CAS CSCD 北大核心 2014年第6期49-56,共8页
为鉴定产甲酸草酸杆菌(Oxalobacter formigenes)是否具有细胞数群体感应(QS)系统,将费氏弧菌(Vibrio fischeri)和荧光假单胞菌(Pseudomonas fluorences)QS系统相关基因与产甲酸草酸杆菌(O.formigenes)基因组序列进行比对,初步确定hdtS和... 为鉴定产甲酸草酸杆菌(Oxalobacter formigenes)是否具有细胞数群体感应(QS)系统,将费氏弧菌(Vibrio fischeri)和荧光假单胞菌(Pseudomonas fluorences)QS系统相关基因与产甲酸草酸杆菌(O.formigenes)基因组序列进行比对,初步确定hdtS和AGPA为QS系统候选基因。通过PCR和T-A克隆方法分别克隆以上两个基因并将其构建成表达载体pET19-hdtS和pET19-AGPA,借助SDS-PAGE凝胶电泳证实以上两个基因均在大肠杆菌(Escherichia coli)BL21(DE3)中高效表达,采用平板菌株报告法鉴定hdtS具有酰基高丝氨酸内酯(AHL)合成酶的功能,而AGPA则不具有该功能。这是国内外首次报道产甲酸草酸杆菌(O.formigenes)中QS系统有关基因,对该菌株QS系统了解及分析影响该菌株在人肠道内定殖因素具有重要意义。 展开更多
关键词 克隆 鉴定 产甲酸草酸杆菌 细胞群体感应系统 hdtS AGPA
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三维石油遥感应用中多时相影像数据管理 被引量:3
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作者 郭红燕 邹立群 +2 位作者 董文彤 刘杨 周红英 《遥感信息》 CSCD 北大核心 2016年第4期129-133,共5页
针对目前多时相影像数据管理主要是面向影像产品管理,仅考虑影像产品本身的信息作为管理要素,无法满足石油行业遥感应用要求这一问题,提出一种面向三维石油遥感应用的多时相数据管理方法,通过采用数据组织目录结构与瓦片存储目录结构相... 针对目前多时相影像数据管理主要是面向影像产品管理,仅考虑影像产品本身的信息作为管理要素,无法满足石油行业遥感应用要求这一问题,提出一种面向三维石油遥感应用的多时相数据管理方法,通过采用数据组织目录结构与瓦片存储目录结构相结合的方式,建立了多时相影像数据的分级管理与访问。该方法满足石油遥感应用多样性、应用的油区范围分散、多数据源组合、油区变化性检测的要求,并以鄱阳湖三角洲环境变化中多时相数据管理为例进行了软件实现。 展开更多
关键词 三维石油遥感应用 多时相影像管理 据组织结构 影像瓦片 据存储
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用地磁感应转数传感器实现引信定距方法的研究 被引量:8
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作者 赵捍东 张亚 陈宏伟 《探测与控制学报》 CSCD 北大核心 2002年第1期57-60,共4页
根据地磁场特性及电磁感应原理 ,提出了地磁感应转数传感器的总体结构 ,建立了传感器的数学模型 ,并通过实验 ,精确地测出弹丸转数及地磁感应电动势波形。阐述了磁感应转数传感器实现引信定距的实际应用方法。
关键词 地磁场 地磁感应传感器 引信定距 感应电动热
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浅谈如何帮助小学生建立数感
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作者 杨东升 《中文科技期刊数据库(全文版)教育科学》 2019年第4期96-97,共2页
学中文要培养语感,学英语也要培养语感,那么学数学要培养什么呢?那就是数感。想要学生学好数学,就要使学生建立数感。根据新的《数学课程标准》对数学教学提出了培养学生数感的要求。本文结合个人的教学经验与实际操作,对如何培养数感,... 学中文要培养语感,学英语也要培养语感,那么学数学要培养什么呢?那就是数感。想要学生学好数学,就要使学生建立数感。根据新的《数学课程标准》对数学教学提出了培养学生数感的要求。本文结合个人的教学经验与实际操作,对如何培养数感,作浅显的探讨。 展开更多
关键词 学素养 感建立 感培养 数感应用
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用热壁CVD法在SiC衬底上生长SiCGe合金的热场分析与设计 被引量:4
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作者 蒲红斌 陈治明 +4 位作者 李留臣 封先锋 张群社 沃立民 黄媛媛 《人工晶体学报》 EI CAS CSCD 北大核心 2004年第5期712-716,共5页
采用有限元法,对热壁CVD法SiCGe合金生长炉中加热组件的感应加热和温度分布进行了研究。分析了感应线圈匝数和石墨衬托的厚度对磁矢势和温度分布的影响,获取了感应线圈数越多感应生成焦耳热越大且越均匀的结论,得出了随石墨厚度的增加... 采用有限元法,对热壁CVD法SiCGe合金生长炉中加热组件的感应加热和温度分布进行了研究。分析了感应线圈匝数和石墨衬托的厚度对磁矢势和温度分布的影响,获取了感应线圈数越多感应生成焦耳热越大且越均匀的结论,得出了随石墨厚度的增加升温速率而增加,相反轴向温度均匀性而变差的设计准则。模拟结果表明选取16匝线圈和10mm左右的石墨壁厚为优化的设计参数。 展开更多
关键词 碳化硅 碳硅镓化合物 温度场 优化设计 热壁化学气相沉积法 感应加热 有限元 石墨厚度 感应线圈 半导体材料
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基于微处理器的教室智能用电管理系统 被引量:2
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作者 毛鹏 王伟健 《信息技术》 2014年第10期59-61,67,共4页
随着国内高校规模的不断扩大,高校教学楼数量激增,相应的电费支出已经非常庞大。但事实上,高校教学楼在用电方面却存在诸多问题,体现为电能的巨大浪费,这必须引起足够的重视。针对大学教室在用电管理方面存在的不足,设计了一种教室智能... 随着国内高校规模的不断扩大,高校教学楼数量激增,相应的电费支出已经非常庞大。但事实上,高校教学楼在用电方面却存在诸多问题,体现为电能的巨大浪费,这必须引起足够的重视。针对大学教室在用电管理方面存在的不足,设计了一种教室智能用电管理模拟系统。本系统采用单片机STC89C52作为核心部件,运用红外感应计数以及单片机之间的无线通信,能有效地对教室进行合理的用电管理,实用性强。 展开更多
关键词 STC单片机 教室用电管理 红外感应 无线通信
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由自感应粒子数光栅形成自适应腔平均功率100W的Nd:YAG激光器 被引量:1
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作者 傅恩生 《激光与光电子学进展》 CSCD 2002年第1期33-38,41,共7页
关键词 ND:YAG激光器 感应粒子 平均均率 光栅 自适应腔
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Data acquisition,analysis and applications of multi-sensor integration 被引量:3
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作者 Li Qingquan Liu Yong +1 位作者 Mao Qingzhou Yang Bisheng 《Engineering Sciences》 EI 2010年第1期2-10,共9页
This paper presents some key techniques for multi-sensor integration system, which is applied to the intelligent transportation system industry and surveying and mapping industry, e.g. road surface condition detection... This paper presents some key techniques for multi-sensor integration system, which is applied to the intelligent transportation system industry and surveying and mapping industry, e.g. road surface condition detection, digital map making. The techniques are synchronization control of multi-sensor, space-time benchmark for sensor data, and multi-sensor data fusion and mining. Firstly, synchronization control of multi-sensor is achieved through a synchronization control system which is composed of a time synchronization controller and some synchronization sub-controllers. The time synchronization controller can receive GPS time information from GPS satellites, relative distance information from distance measuring instrument and send space-time information to the synchronization sub-controller. The latter can work at three types of synchronization mode, i.e. active synchronization, passive synchronization and time service synchronization. Secondly, space-time benchmark can be established based on GPS time and global reference coordinate system, and can be obtained through position and azimuth determining system and synchronization control system. Thirdly, there are many types of data fusion and mining, e.g. GPS/Gyro/DMI data fusion, data fusion between stereophotogrammetry and PADS, data fusion between laser scanner and PADS, and data fusion between CCD camera and laser scanner. Finally, all these solutions presented in paper have been applied to two areas, i.e. land-bone intelligent road detection and measurement system and 3D measurement system based on unmanned helicopter. The former has equipped some highway engineering Co. , Ltd. and has been successfully put into use. The latter is an ongoing resealch. 展开更多
关键词 multi-sensor integration synchronization control of multi-sensor space-time benchmark data fusion
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Improving wavelet reconstruction algorithm to achieve comprehensive application of thermal infrared remote sensing data from TM and MODIS 被引量:1
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作者 周启刚 Chen Dan 《High Technology Letters》 EI CAS 2015年第2期224-230,共7页
According to the data characteristics of Landsat thematic mapper (TM) and MODIS, a new fu sion algorithm about thermal infrared data has been proposed in the article based on improving wave let reconstruction. Under... According to the data characteristics of Landsat thematic mapper (TM) and MODIS, a new fu sion algorithm about thermal infrared data has been proposed in the article based on improving wave let reconstruction. Under the domain of neighborhood wavelet reconstruction, data of TM and MO DIS are divided into three layers using wavelet decomposition. The texture information of TM data is retained by fusing highfrequency information. The neighborhood correction coefficient method (NC CM) is set up based on the search neighborhood of a certain size to fuse lowfrequency information. Thermal infrared value of MODIS data is reduced to the space value of TM data by applying NCCM. The data with high spectrum, high spatial and high temporal resolution, are obtained through the al gorithm in the paper. Verification results show that the texture information of TM data and high spec tral information of MODIS data could be preserved well by the fusion algorithm. This article could provide technical support for high precision and fast extraction of the surface environment parame ters. 展开更多
关键词 neighborhood wavelet reconstruction neighborhood correction coefficient method( NCCM) thematic mapper (TM) MODIS thermal infrared remote sensing image
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Information Service System for Receiving and Processing Multi Source Remote Sensing Images
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作者 GUO Xiarui NING Wei HU Gang 《Aerospace China》 2016年第4期41-46,共6页
Based on international requirements for the application of commercial remote sensing data,an information service system for receiving and processing multi source remote sensing data was developed and introduced.The sy... Based on international requirements for the application of commercial remote sensing data,an information service system for receiving and processing multi source remote sensing data was developed and introduced.The system consists of an Oversea Fixed Ground Service Station(OFGS),a Transportable Vessel-Borne Service Station(TVBS) and a Data Operation and Management Center(DOMC).Fixed and transportable service stations were developed in Venezuela,Latin America and for the China's Xuelong polar research vessel respectively,and serve the function of remote sensing data receiving,processing and application.The DOMC connects the OFGS and TVBS,so that they constitute a network to provide receiving,distribution,retrieval,browsing,ordering,and downloading functions for multi remote sensing satellite data and products.It validates the competence in providing 40 kinds of typical application products.The development of this system provides a reliable and comprehensive service for commercial remote sensing data applications for users both in domestic and oversea markets. 展开更多
关键词 Remote sensing Commercial aerospace Satellite application
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电磁测深中阻抗等效电阻率的讨论及其算法——水平多层大地上垂直磁偶极子频率电磁测深
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作者 汤井田 鲍光淑 《勘察科学技术》 1994年第1期59-62,共4页
本文论讨了水平多层大地上垂直磁偶极子频率电磁测深中阻抗定义的等效电阻率及其算法。
关键词 等效电阻率 感应 电磁测深 阻抗
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Research and application of flood detention modeling for ponds and small reservoirs based on remote sensing data 被引量:4
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作者 CAO MingLiang ZHOU HuiCheng +3 位作者 ZHANG Chi ZHANG AiJing LI HuiYun YANG Yang 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第8期2138-2144,共7页
This paper proposes a method of small reservoir flood detention modeling that utilizes data from the American land resources satellite Landsat TM/ETM+. Precipitation and potential evapotranspiration are taken as the c... This paper proposes a method of small reservoir flood detention modeling that utilizes data from the American land resources satellite Landsat TM/ETM+. Precipitation and potential evapotranspiration are taken as the control conditions in this method on the basis of basin terrain classification. The objective of this method is to solve the question of a small-scale water conservancy project’s influence on flood forecasting precision, which can be used in the basin with multitudinous small reservoirs in the upstream region and can help estimate non-runoff data for small reservoir runoff. Taking the 20060826 flood as an example, the flood detention quantity of 19 small reservoirs is modeled. The results show that the absolute error of the total flood detention quantity is 0.2×10 4 m 3 , and the relative error is 0.12%. The flood detention quantity of small reservoirs in the entire basin is then modeled using this method, and the primary flood forecasting model is adjusted. After adjustment, the precision is significantly improved, with the relative error decreasing from 31.8% to 10.1%. 展开更多
关键词 remote sensing data small reservoir flood detention modeling
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An in-plane low-noise accelerometer fabricated with an improved process flow 被引量:3
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作者 Xu-dong ZHENG Zhong-he JIN Yue-lin WANG Wei-jun LIN Xiao-qi ZHOU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第10期1413-1420,共8页
We present a bulk micromachined in-plane capacitive accelerometer fabricated with an improved process flow,by etching only one-fifth of the wafer thickness at the back of the silicon while forming the bar-structure el... We present a bulk micromachined in-plane capacitive accelerometer fabricated with an improved process flow,by etching only one-fifth of the wafer thickness at the back of the silicon while forming the bar-structure electrode for the sensing capacitor.The improved flow greatly lowers the footing effect during deep reactive ion etching(DRIE),and increases the proof mass by 54% compared to the traditional way,resulting in both improved device quality and a higher yield rate.Acceleration in the X direction is sensed capacitively by varying the overlapped area of a differential capacitor pair,which eliminates the nonlinear behavior by fixing the parallel-plate gap.The damping coefficient of the sensing motion is low due to the slide-film damping.A large proof mass is made using DRIE,which also ensures that dimensions of the spring beams in the Y and Z directions can be made large to lower cross axis coupling and increase the pull-in voltage.The theoretical Brownian noise floor is 0.47 μg/Hz1/2 at room temperature and atmospheric pressure.The tested frequency response of a prototype complies with the low damping design scheme.Output data for input acceleration from ?1 g to 1 g are recorded by a digital multimeter and show very good linearity.The tested random bias of the prototype is 130 μg at an averaging time of around 6 s. 展开更多
关键词 MEMS accelerometer Deeo reactive ion etchin (DRIE) Footin effect Canacitive sensing
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