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1.
牟其铎教授是国家地震局地球物理研究所研究员、中国数字地震台网技术管理研究室主任。本文包括：作一个线性系统的地震观测系统、数字地震记录的压缩、数字地震记录的格式三部分。 相似文献
2.
Daoyuan Sun 《地震科学（英文版）》2022,35(1):58-60
It has been more than a year since Don left us.He left us so suddenly.We planned to have a phone call after he settled down at his new house.However,it never ha... 相似文献
3.
Mahfooz A. Hafez Magdy A. Atya Azza M. Hassan Motoyuki Sato Thomas Wonik Abeer K EI-Kenaw 《应用地球物理》2008,5(2):136-143
Ground penetrating radar, electromagnetic terrain conductivity, and electric tomography have proven to be effective tools if they are combined together to investigate archeological sites. We have conducted a geophysical survey at the Akhmim archaeological site, the main objective of our survey is to locate additional buried structures for further excavation. Geophysical data were acquired in the area using the GEM-300 multi-frequency terrain conductivity profiler, the SIR 2000 ground penetrating radar, and the Syscal R2 resistivity meter systems. The results of the integrated interpretation show a number of buried features and a strong linear zone about 1 m wide that coincides with the suspected trend of a buried wall. There appears to be two parallel ridges of strong reflections on either side, indicating two parallel walls extended East-West and a room is identified at the bottom left comer of the site. Moreover, the interpretation results of some selected GPR and dipoledipole resistivity profiles adjacent to the open-air museum suggest the existence of a second statue of Ramses Ⅱ to the right of the previously discovered statue which could still be buried in the sand. 相似文献
4.
《Journal of Atmospheric and Solar》2007,69(14):1600-1603
Eyvind Sucksdorff (1899–1955) was an enthusiastic scientist who was the director of Sodankylä Geophysical Observatory (SGO) from 1927 to 1945. He continued magnetic measurements, which were started in 1913 when SGO was established. Sucksdorff observed events with periodically modulated amplitude in the registration of the new La Cour quick-run magnetometers in 1932–35. He interpreted these events to be due to short-period oscillations and called them “rapid micropulsations” or “pearl necklace” due to the shape of the signal in the registration. From the “pearl necklaces” he estimated the upper bound of the oscillation to be 2–3 s. Sucksdorff did not know the accurate values of the eigenperiods of the systems (H, D and Z components of the magnetometer). Later measurements have shown that they were 2–3 s. Nowadays, the pearl pulsations discovered by Sucksdorff 70 years ago are known as a subgroup of Pc1 magnetic pulsations. Sucksdorff published his observations in 1936. He studied both the annual and diurnal distributions of the new pulsations. Comparisons of the records made in Stockholm, Copenhagen and Sodankylä revealed for the first time the global features of Pc1 pulsations. Sucksdorff did not present any explanation for the pearl pulsations he had observed. Leiv Harang from the Auroral Observatory at Tromsø, Norway, published his analysis of rapid registrations made in Tromsø in 1932–36 in the same issue of the Terrestrial Magnetism and Atmospheric Electricity. He used the name “vibrations” for his short-period oscillations. 相似文献
5.
James W. Skehan 《Journal of Geodynamics》2004,37(3-5):301
Nicholas Rast died in Lexington, Kentucky on 28 August 2001, five months after his retirement as the first holder of the Hudnall Chair of Geology, Department of Geological Sciences, University of Kentucky. Born in Teheran in 1927, his early education was in Iran; his university education from 1948 was at University College London and University of Glasgow. His brilliant career as a university professor and award-winning researcher began in Aberystwyth, University of Wales, University of Liverpool, and continued in North America at the University of New Brunswick, Canada, and at the University of Kentucky, USA. Rast's published research consists of over 100 books and papers as well as abstracts in scientific journals. The abstracts represent topics which Nick Rast and his collaborators presented to participants at scientific meetings, symposia, and conferences; he was never one to let a good idea lie fallow, and I think it is accurate to say that every abstract evolved into a published paper. Wherever Nick worked he became deeply involved in influential activities of the geological societies of the country and in so doing left his imprint on the policies of these societies in England, Wales, Scotland, Ireland, Mexico, Canada and the United States. The organization of this retrospective deals generally with the chronology of Nick Rast's life and career. It includes a selection from among his most significant peer-cited reviewed publications, all of which are listed at the end of this chapter. From this list I have attempted to highlight some of the most important ideas contained in these publications. In addition I have interspersed a few colorful reminiscences by Nick's many friends, colleagues, and former students. These recalls were part of my “Rastfest” retirement banquet illustrated lecture which is now available on the Kentucky departmental website. 相似文献
6.
１９９５年１月１７日日本兵库县南部淡路岛发生７．２级地震后，正在工作的本文作者亲临地震灾区，进行了现场调查，作者以日记的形式叙述了现场调查情况，此外，他还给出了自己对灾害的分析。 相似文献
7.
《Journal of Atmospheric and Solar》2007,69(3):351-361
Chung Park (1938–2003) was a true pioneer of magnetosphere–ionosphere coupling research. During a short career at Stanford University that began in 1970 and ended in 1981, he wrote seminal papers on several topics. Using ground-based whistler data, he was the first to demonstrate experimentally that day-side upward ion flow from the mid-latitude ionosphere was sufficient to maintain the night-time ionosphere. He made the only measurements to date of longitudinally localized drainage of significant quantities of plasmaspheric plasma into the underlying ionosphere during a period of enhanced convection activity. He pioneered in demonstrating the presence at ionospheric heights of geophysically important electric fields that originate in the troposphere in thunderstorm centers. He cooperated in a unique study of the guidance of whistler-mode waves by field-aligned density irregularities (ducts) in the magnetosphere. Park provided unique observational data on nonlinear wave–particle interaction processes such as: (i) the development of sidebands during the injection of whistler-mode waves from Siple, Antarctica, and (ii) the mysterious whistler precursor phenomenon. Today, in spite of the several decades that have elapsed since his work, Park's early findings remain cornerstones of our understanding of magnetosphere–ionosphere coupling processes. Some of his later studies of non-linear magnetospheric wave–particle interaction phenomena have stirred lively debate, and today remain relevant to a number of topics in space plasma wave research. 相似文献
8.
In "Airs, Waters and Places, " Hippocrates taught aspiring physicians that, to understand their patient's illness, they needed to understand their patient's environment. He recognized that people's well-being was linked to their environment. Hippocrates instructed his readers to use observations of the seasons, the water and the orientation of a city to classify the major health problems of the inhabitants. While his causal framework for explaining the pathogenesis of disease may seem rudimentary and misguided in light of today's medical understanding, Hippocrates knew that many health problems arose from our interactions with the environment and he tried to do what we continue to want to do today: to predict the occurrence of disease in order to better care for his patients. 相似文献
9.
Codie Wilson Stephanie K. Kampf Joseph W. Wagenbrenner Lee H. MacDonald Hunter Gleason 《地球表面变化过程与地形》2021,46(1):267-279
Sediment fences are often used to monitor hillslope erosion, but these can underestimate sediment yields due to overtopping of runoff and associated sediment. We modified four sediment fences to collect and measure the runoff and sediment that overtopped the fence in addition to the sediment deposited behind the fence. Specific objectives were to: (1) determine the catch efficiency of sediment fences measuring post-fire hillslope erosion; (2) assess particle sorting of sand, silt/clay, and organic matter from each hillslope through the sediment fence and subsequent runoff collection barrels; (3) evaluate how catch efficiency and particle size sorting relate to site and rainfall-runoff event characteristics; and (4) use runoff simulations to estimate sediment fence volumes for future post-fire monitoring. Catch efficiency ranged from 28 to 100% for events and 38 to 94% per site for the entire sampling season, indicating a relatively large underestimation of sediment yields by sediment fences. Most of the eroded sediment had similar proportions of sand and silt/clay as the hillslope soils, but the sediment behind the fence was significantly enriched in sand while the sediment that overtopped the fence was more strongly enriched in silt/clay. The sediment fences had capacities of 3 m3 for hillslopes of 0.19–0.43 ha, but simulations of runoff for 2- to 100-year storms indicate that the sediment fences would need a capacity of up to 240 m3 to store all of the runoff and associated sediment. More accurate measurements of sediment yields with sediment fences require either increasing the storage capacity of the sediment fence(s) to accommodate the expected volume of runoff and sediment, reducing the size of the contributing area, or directly measuring the runoff and sediment that overtop the fence. © 2020 John Wiley & Sons, Ltd. 相似文献
10.
1996 is the centenary of the birth of Brigadier Ralph Alger Bagnold, FRS. To mark this important anniversary this paper presents a short biography of Bagnold and an extended bibliography of his published work. The purposes of the paper are firstly, to present a synthesis of the life and significant discoveries made by Brigadier Bagnold, secondly, to communicate something of the character of the man and his work to generations of researchers who have not had the chance to meet him at first hand, and finally, to use this Technical Supplement and Software Bulletin to make summaries of his theories, empirical findings and views on science accessible to students and scholars of physical geography, geomorphology and engineering. 相似文献
11.
基于GPS TEC数据,对1998年11月1日-2010年12月31日中国大陆MS≥6.0地震临震电离层扰动进行了研究.分析发现,震中上空及周围的东、南、西、北4个方向震前15天到地震当天时序变化趋势较相似,5个方向都观测到了震前3-5天负异常稍高于正异常的现象.按震中±10°、±20°、±30°不同空间尺度分析震前0-15天TEC变化,研究表明临震电离层异常最明显的区域并不位于震中的正上空,而是向磁赤道方向偏移,空间影响尺度大约为±15°左右;正异常在震前14天、10天震中西南方向出现不同程度的高值区,负异常在震前5天震中东南方向较明显.最后,应用静电场假设对这些现象进行了解释. 相似文献
12.
JACQUES BERTIN 《Geophysical Prospecting》1968,16(4):401-426
In the first part, the author, recalling the principle of d/c current measurements, shows by means of some examples, different experimental results relative to the induced polarization phenomenon. He presents the case of the negative induced polarization which can be explained by geometric effects. He gives some examples of saturation curves and discusses the problem of the linearity of the I.P. phenomenon. Then he shows some aspects which demonstrate that I.P. decay curves do not always conform to the general law. He concludes by showing the influence of the current electrodes, the position of which, relative to the polarizable bodies, may alter the shape of the I.P. anomalies. In the second part, the author presents different case histories of I.P. mineral surveys where I.P. is compared to other geophysical methods and drilling results. 相似文献
13.
张衡地动仪的诞生 总被引：1，自引：1，他引：0
地动仪的诞生有着深厚的历史背景,本文旨在探讨张衡科学思想的形成过程和物质基础.张衡生活在东汉文化发展的顶峰时期,“观察异象、辨别凶吉”的朴素愿望是研制地动仪的原始动力.作者追溯了当时的历史背景、张衡的学术历程、地动仪的问世过程,分析了东汉早期的地震活动、古代的地震观念和灵台科学活动的特点.指出地动仪的研制起步于公元128年,张衡基于感性认识升华出两个地震概念——地震的位置可按方位判断、地震和地裂必须加以区别,这使地动仪的研制有了明确的技术追求.仪器制作上,张衡崇尚“制器尚象”的原则.地动仪的测震原理模仿了悬挂物(即天然验震器)对地震的反应,技术实现上借鉴了门闩类的触发机构,还通过龙首吐丸的方式留下了发生地震的物质证据,这3个关键问题的解决成就了公元132年地动仪的问世和134年的成功验震,构成他科技创新的完整内容.地动仪的发明深化了人类对自然规律的认识,对当时的东汉及其后世界文化的发展具有积极意义. 相似文献
14.
Abstract Accumulations of snow behind fences may increase the water yield in windswept areas. The efficiency of snow collection depends on the reduction in wind speed in the lee of the fence. Wind speeds have been measured to windward and to leeward of vertical slat fences from 6 to 16 ft. high. The down-wind measurements were made at distances of 2.5H, 5H and 10H from the fence where H is the height of the fence. Speed measurements at various levels were integrated up to the height of the fence and the percentage reduction in wind speed was calculated. Expressions are given for the velocity reduction factor at distances down-wind of fences having a bottom gap, and for the cross-sectional area of a fully developed drift. 相似文献
15.
将伪随机编码技术引入到人工源电磁法后,可以通过加大发射功率以及应用后续的相关处理技术来达到压制噪声、加大探测深度及提高分辨率的目的,因此引起了越来越多学者的关注及研究,但大多数研究集中在资料处理的相关技术上,对模拟电磁信号关注较少.然而,资料处理工作大多是从电磁信号出发的,模拟伪随机编码源激发下的电磁信号不但可以为资料处理环节提供理论数据,而且可以为检测资料处理的效果提供中间结果,因此,模拟电磁信号工作必不可少.本文根据获得接收信号的物理过程来实现伪随机编码源激发下的电磁信号合成.首先用解析公式获得特定地电结构的大地频率域响应,然后通过余弦变换得到时间域阶跃响应,接下来用阶跃响应的时间导数得到大地脉冲响应,通过将大地脉冲响应与伪随机编码源的褶积得到理想接收信号,最后,用低通滤波器来模拟发射设备和接收设备的频带限制,将之和噪声一起加到理想接收信号上,最终模拟出仿真的合成信号.通过和野外实际接收信号对比发现本文合成信号仿真度较高,可以服务于后续的数据处理环节. 相似文献
16.
Gordon Woo 《Bulletin of Earthquake Engineering》2014,12(1):127-134
The study of historical earthquakes itself has an interesting history, and Nick Ambraseys figures highly in it. This historiographic tribute relates the pivotal role that he played in the development of the British and Scandinavian Earthquake Archives. Maintaining his academic distance from direct hazard consulting, he nevertheless exerted a significant influence on the scientific conduct of hazard analyses. From the collection of instrumental and macroseismic data to the assignment of magnitudes, the modus operandi which he recommended was followed in pioneering seismic hazard studies in Britain, the North Sea and Norway, during the 1980s. Because of the confidentiality of seismic hazard reports produced for the UK nuclear industry, there is little record in the open seismological literature of the contribution of Nick Ambraseys. As a civil engineer, he had an exceptional interest in the earthquake evidence that could be gleaned from historical documents. An illustrative reference is given to the discovery of fresh evidence from an Aegean earthquake that shows how even the most knowledgeable of earthquake historians can be surprised. 相似文献
17.
《Astronomy& Geophysics》2008,49(2):2.39-2.39
Now that the Society has returned to Burlington House, normal life can resume, and that includes Saturday opening of the Library. 相似文献
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19.
S. Ghoshal 《Pure and Applied Geophysics》1970,80(1):335-345
Summary In this article, we have solved the problem of natural convection along a vertical plate with variable temperature and a transverse non-uniform magnetic field. It also represents a unified analysis of the works of other including the present author, on natural convection with or without transverse magnetic field, and with uniform or non-uniform plate temperature.The author is indebted to Prof.K. B. Ranger, Department of Mathematics, for his continuous and active interest in my research work. I am also grateful to him for offering me a fellowship from his N.R.C. (Canada) research fund. 相似文献
20.
1997年西藏玛尼7.5级地震2001年青海昆仑山口8.1级地震震前中长期预测 总被引：2，自引：3，他引：2
作者在1996年底对中国大陆2005年前6级以上强震危险区（13处）作出了预测，其中对应1997年玛尼7.5级地震、2001年昆仑山口8.1级地震，取得了很好的预报效果。本文分时段：1996年底前、1997年11月前、2001年11月前，分别总结了预测依据及震情跟踪分析。加上对同期（1997－2001年）其他强震预测的实际对应，表明地震活动图像分析方法在分析预报研究中是可以有所作为的。 相似文献