宽频带海底地震仪的研制

为填补我国海洋地震监测和海洋地震研究的空白,获得对海洋地震多发区域的监测能力,特此进行宽频带海底地震仪的研制.本文详细介绍了宽频带海底地震仪的设计目标、基本工作原理、组成结构及性能技术指标和研制过程.此外,还介绍了宽频带海底地震仪在中国南海东北部海域应用实例的实验结果,展示了宽频带海底地震仪在3000m海底所记录到的数据资料.     

地震仪器中应用的网络通讯技术研究

网络通讯是决定地震勘探仪器系统性能和规模的关键核心技术之一,按照所采用的数据传输方式,数字地震仪目前可分为有线遥测地震仪、无线遥测地震仪和无缆存储式地震仪.本文分别举例介绍了三类地震勘探仪器中应用的经典地震网络通讯技术,并对其设计理念、网络通讯原理、通信构架、通信协议进行了分析和对比,针对有线地震仪器的电缆管理难、无线地震仪器的数据传输稳定性差和无缆存储式地震仪缺少质量监控手段的问题,讨论了无线监控与本地存储相结合的地震网络通讯技术方案,提出了基于宽带无线通信技术的无缆无线混合型地震仪的设想.     

地震传感器的新技术与发展

宽频带、大动态、低噪声、低功耗、便携式、高度智能化是地球物理观测技术的发展趋势.本文简要回顾了地震传感器的发展,详细介绍了几种设计先进、性能优越、基于不同换能机理的新型地震传感器.这些传感器有些已经有原理样机,有些还处于概念设计中,它们将是未来宽频带地震仪技术发展的主要方向.     

大型维歇特地震仪的记录特征及其在地震速报中的作用

大型维歇特地震仪自德国引进南京地震台已近70年。本文简要叙述了该仪器的性能；并以南京地震台的大型维歇特地震仪的记录为例，介绍了该仪器在300-2000km范围内的记录特征，回顾了该仪器在地震速报中所起的历史作用。     

一种新型潜标式海洋地震仪及在海洋地震探测中的应用

本文介绍了一种面向全球海洋地震P波长期探测的新型潜标式海洋地震仪.该地震仪不同于传统的固定式陆地地震台站或者坐底式海底地震仪,而是漂浮在海水中一定深度接收天然地震信号,并随着洋流运动.当接收到地震P波信号后,该地震仪可以自动上浮至海面,并通过卫星将数据传回岸基中心,然后下沉到指定深度继续工作.该潜标式海洋地震仪主要由水听器模块、浮力调节模块、通信与传输模块、能源模块以及中央控制模块组成,同时有安全监测功能,以实现准实时、大范围的天然地震P波信号长期监测.该海洋地震仪将突破现有海洋地震观测技术局限,拓展海洋地震监测的时空覆盖范围及监测尺度,为海洋地震研究和地球深部构造提供准确可靠的数据.     

高分辨率数字地震仪的实验研究

为提高数字地震仪的分辨率和扩大动态范围,本文简要介绍了在地震仪设计中应用激光移频技术的新思路,简述了其基本原理及初步实验结果,用光ｆ干涉原理制作地震仪能够获得很高的准确度和较高的分辨率,动态范围可达１６０ｄＢ．     

高分辨率数字地震仪的实验研究

为提高数字地震仪的分辨率和扩大动态范围，本文简要介绍了在地震仪设计中应用激光移频技术的新思路，简述了其基本原理及初步实验结果，用光ｆ干涉原理制作地震仪能够获得很高的准确度和较高的分辨率，动态范围可达１６０ｄＢ．     

宽频带地震仪性能现场检测方法进展研究

宽频带地震仪具有采样信号频带宽、动态范围广及采样精度高的特点,常布设于野外流动地震台站中进行长时间的地震观测,利用宽频带地震仪及由其组成的观测系统进行科学研究已成为近年来的发展趋势．由于野外环境存在大量不确定因素,这些变化可能会导致宽频带地震仪性能改变,从而影响数据质量．现场检测作为地震仪器性能检测的一种方法,无需改变仪器的布设位置能够保证仪器采集的连续性,同时考虑野外现场因素的影响．因此,宽频带地震仪性能的现场检测也越来越受到国内外学者的重视．本文以野外宽频地震仪性能检测为研究方向,从仪器性能的影响因素、原位校准方法以及利用观测数据评估仪器性能这三个角度出发：（1）论述了布设位置及方式、温湿度及大气压力变化对仪器性能的影响;（2）介绍了仪器原位校准中的电测法和对比测量法;（3）总结了利用地震信号、地震背景噪声以及潮汐信号对宽频地震仪性能进行现场检测的方法．最后,本文对目前宽频地震仪性能检测方法存在的问题进行分析总结,并对其发展前景提出展望．     

FBS-3，JCZ-1数字地震仪记录震级的误差分析

利用延边地震台两套数字地震仪,分别对100个地震的震级与标准震级作了比较,可以看出,JCZ-1地震仪具有明显的优势。以往研究主要比较模拟和数字地震仪的震级偏差,本文针对不同的数字地震仪,讨论了两者差别,得出了延边地震台的远震震级校正参数。     

DD－1型短周期地震仪改制

本文介绍了改制后ＤＤ－１型地震仪放大器、稳频器、稳压器的工作原理，简述了其主要技术指标，并给出了仪器的标定和试验结果．ＤＤ－１型短周期地震仪改制。是为了使仪器更好地适应地震预报与基础研究的观测需要而进行的。将改制后的仪器经室内测试标定和实际观测，并与沈阳地震基准台记录进行对比分析，证明改制后的ＤＤ－１型短周期地震仪主要技术指标与工作性能已达到规范的要求．     

A Monte Carlo study of rainfall forecasting with a stochastic model

A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities.     

Earthquake Engineering and Engineering Vibration Aims And Scope

正This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and     

Foreword

Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States.     

WORLD ASSOCIATION FOR SEDIMENTATION AND EROSION RESEARCH(WASER)

正President:Giampaolo Di Silvio,Italy Vice Presidents:Ulrich C.E.Zanke,Germany Zhao-yin Wang,China The World Association for Sedimentation and Erosion Research(WASER),inaugurated on Oct.19,2004,is an independent non-governmental,non-profit organization.The mission of WASER is to promote international co-operation on the study     

Enhancing remote sensing research on global change to improve our understanding on Earth system processes

正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases     

SCIENCE CHINA Earth Sciences SUBJECT INDEX TO VOLUME 57(2014)

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