Studies on Schumann Resonance Phenomena and Some Recent Advancements

Geomagnetism and Aeronomy - Discrete spectra of frequencies at 8, 14, 20, 26, … Hz are generated by electromagnetic emission from lightning sources and can be regarded as excitation of AC...     

汶川地震房屋震害的一些现象分析

The MS8.0 Wenchuan earthquake caused a great deal of damage and collapse to engineering structures. Survey of disaster and engineering damage was made in detail by the authors and other researchers in the extreme earthquake disaster area. The paper makes an overview of the earthquake disaster status and damage phenomena which include brick-concrete buildings, frame structures, brick-wood structures, and timber frame residential buildings. Furthermore, the causes of the disaster and building damage phenomena are briefly discussed. In addition, some typical damage phenomena are specialized. According to the phenomena mentioned above, some feasible seismic measures are suggested for the development of buildings in future.     

Preliminary Analysis of Tectonic Deformation Phenomena in Some Archaeological Sites in Shandong Province

Earthquake archaeological research was conducted in recent years at four archaeological excavation sites in Shandong, focusing on the identification and analysis of the tectonic deformation phenomena. The non-tectonic deformation phenomena were distinguished at the site of the Shang Dynasty ruins at Daxinzhuang in the Jinan suburbs. In Longshan, sand vein-filled cracks were recognized in the cultural layers of the Chengziya site, Zhangqiu City. Sand veins on the trench wall and sand tubes at the trench bottom were found densely distributed at the Shang and Zhou Dynasty cultural layers, at Qinhuangtai site, Binzhou City. The tectonic and non-tectonic origin cracks were identified on the city wall of the Site of Capital of State Qi, Linzi City. In Rizhao city, parallel distributed sand vein fracture groups were found in the cultural layer of Longshan-Warring States-Han Dynasty at Yaowangcheng site. Typical conjugate shear fractures were identified on the city wall of the ancient city of the State of Xue, Tengzhou City. The above natural deformation phenomena are concentrated in the culture layers of the Spring and Autumn-Warring States-Han Dynasties and before, and characterized by seismic sand-soil liquefaction traces, which indicate that these regions might have been in the seismic active episodes in the corresponding periods. The above inference has been confirmed by microscopic data analysis.     

Some early Russian studies of subsurface storm‐flow processes

Subsurface flow is an important component of the catchment hydrological cycle. Various mechanisms of this process and their role in storm‐flow generation attracted the attention of many researchers throughout the twentieth century. The results of most of these studies are well documented. However, similar studies conducted in the past by many Russian hydrologists have never been made available to the English speaking hydrological community. This paper attempts to fill this gap and briefly review some of these investigations, focusing on their main results. It starts with the review of the early experimental studies (after 1930s–1950s), which allow the main characteristics of subsurface storm flow to be established. This is followed by a review of the research conducted in 1960s, which resulted in some conceptualization of the subsurface flow mechanisms. The paper also draws some parallels between this, mostly unknown, subsurface flow research in Russia and the better‐known contemporary studies of this process. Copyright © 2002 John Wiley & Sons, Ltd.     

地震波散射研究的若干重要进展

本文从地球介质的复杂性与非均匀性的普遍性以及地震波在其中的传播过程的复杂性出发,对地震波散射理论及方法研究的历史进行了简要的回顾,并对该领域从20世纪90年代以来的某些进展作了简要的介绍与评述.本文分两大部分进行阐述.(1)．历史回顾：简介并回顾了地震波散射理论几十年的发展历程、存在的问题及对解决这些问题的潜在的基本途径.(2)．20世纪90年代以来的若干进展：简要介绍了弱散射理论体系的形成及强散射问题研究的部分成果,提出了散射理论未来发展的可能方向之一,即在无近似的拟微局部分析理论的基础上,建立并发展可处理高度复杂的地球固体介质中地震波传播问题的地震波散射及全波理论.     

Some effects of sewage discharge upon phytoplankton in Hong Kong

The coastal waters of Hong Kong constitute a transition from estuarine conditions in the west to more oceanic conditions in the east, with a major discharge of untreated sewage located at the mid-point. Chlorophyll a was determined and net phytoplankton was sampled at 45 stations throughout this transition. Over a period of 20 months, chlorophyll a values rarely exceeded 2 μg l.^?1 in unpolluted coastal waters. Estuarine waters generally contained 2–6 μg l.^?1 and, in waters influenced by sewage discharge, values sometimes exceeded 20 μg l.^?1. There was no evidence of a reduction in taxonomic diversity in polluted areas except in summer, when the net phytoplankton was dominated by Chaetoceros spp. In the autumn and early winter, Skeletonema costatum was abundant in the central polluted areas.     

日本地震学会组织召开“居民地震讨论会”

日本岩手宫城内陆地震40天后的2008年7月26、27日两天,日本地震学会分别在栗原市和一关市,组织召开受灾区居民“居民地震讨论会”。两个会场分别都有100多位居民参加。     

Observed characteristics of sudden commencement absorption

Ionospheric absorption at high latitudes that occurs coincidently with storm sudden commencements (SSC) is categorised as sudden commencement absorption (SCA). Having discounted any solar activity effects on the measurement of SCA this paper describes, for the first time, the basic characteristics of SCA measured over half a solar cycle.It is revealed that the measurement of SCA is not affected by Solar activity, the local time of occurrence of the SSC or the direction of B_z immediately before or after the SSC event. We also show that the median value of expected SCA is best predicted by the step change in IMF magnetic field coincident with the SSC event. This strong correlation between the median value of SCA and the IMF magnitude that occurred during the shock has been formulated to aid propagation prediction.     

Simulation of Physical Phenomena in the Ionosphere and Magnetosphere of the Earth on Krot Plasma Device. Some Results and Prospects

Krot device is a unique installation of the scientific infrastructure of the Russian Federation. It is a source of highly uniform low-temperature plasma that takes up to several tens of cubic meters. The setup makes it possible to perform both scaling laboratory simulations of ionospheric and magnetospheric phenomena in the approximation of unbound plasma, as well as plasma tests of full-size samples of the onboard equipment of spacecraft (SC). The simulation results of the dynamics and interaction of small-scale thermal plasma irregularities occurring during ionospheric heating experiments are presented. The impedance of the small-size models of RESONANCE and STRANNIK SC electric antennas in plasma is measured. The possible use of free-space calibration of antennas in the magnetospheric portions of the orbit in the ELF and VLF ranges is confirmed. The efficiency of a new plasma parameters resonance sensor for the TRABANT SC in the ionospheric range of electron densities is shown.     

地震地质灾害对广州市部分城区工程环境的影响分析

通过震害预测研究,探明地震地质灾害源,应用地理信息系统掌握地震地质灾害源空问分布情况,分析其对工程环境的影响范围和影响程度,有助于政府制定防震减灾规划和城市建设与改造。针对广州市部分城区的地震地质灾害源、建筑物、生命线工程、地震次生灾害源的分布情况,应用基于GIS平台的防震减灾信息管理与地震应急辅助决策系统,分析了该区内地震地质灾害破坏对建筑物、生命线工程和地震次生灾害源的影响。结果表明,城市中的建筑物、生命线工程和地震次生灾害源不同程度地受到地震地质灾害的影响。     

宏观异常现象调查中存在的问题

前言目前 ,地震的宏观异常现象已受到全社会的广泛关注。阪神大地震后 ,在目前还没有寻求到有效的短期预报方法的情况下 ,除进一步认识地震预报研究的重要性外 ,对力武(1 998)、弘原海 (1 996 ,1 998)以及池谷(1 998)等人的研究也作了广泛的介绍。各学科的研究人员开展了学科间的合作 ,关西的“科学研讨会”就是其中一例。现阶段 ,尚未查明异常现象的产生机制 ,同时对异常现象与地震、与预报之间的相关性也说不出个所以然 ,因此给异常现象贴上“不科学”的标签就不足为奇了。在目前尚不能辨识真伪的情况下 ,社会对宏观现象的关心度高涨当然…     

金寨台地倾斜异常信息研究

在研究金寨台地倾斜多年观测资料的基础上,提取地倾斜的正常变化形态及干扰形态.对安徽安庆4.8级、江西瑞昌4.9级等地震前的异常特征进行了分析、总结.结果表明,当倾斜仪出现打破以往年变正常规律的形态及多项指标超出二倍标准差时,即可视为异常出现.当趋势异常出现转折,即可视为进入短期阶段,应注意未来1个月左右地震发生的可能,矢量方向大致指向或背向震中.     

Weighting of Observed Heads for the Inverse Problem

In using least-squares parameter estimation techniques to solve for hydrogeologic parameters, one may use a weighting function to reflect differing reliabilities of head measurements. In studies published to date, the weighting function has been used in an ad boc manner or not at all. The inverse square of the observed hydraulic gradient, adjusted to reflect the modeler's perception of geologic heterogeneity and data reliability, is typically an appropriate weighting function.     

Numerical Modeling of the Observed Wiechert Seismograph Magnification

—The paper presents results of experiments designed to measure the actual dynamic magnification of the Wiechert 1000 kg horizontal seismometer when excited by seismic waves. This is accomplished by comparing 51 digital records of seismic events recorded by the Wiechert and a well calibrated reference seismometer. The results obtained indicate that the magnification of the Wiechert seismometer is influenced by the interaction of its mass and frame, especially for high frequencies. This interaction has been modeled by considering a system of two coupled pendulums, yielding a theoretical dynamic magnification curve which exhibits main features of the observed magnification. The dis crepancy between the nominal and the actual response of the Wiechert seismograph may lead to errors in studies involving spectral analyses of recorded seismograms, and to overestimation of local earth quake magnitudes.     

Observed features of acoustic gravity waves in the heterosphere

According to measurements on the Dynamic Explorer 2 satellite, features of the propagation of acoustic gravity waves (AGWs) in the multicomponent upper atmosphere have been investigated. In the altitude range 250–400 km in wave concentration variations of some atmospheric gases, amplitude and phase differences have been observed. Using the approach proposed in this paper, in different gases, AGW variations have been divided into components associated with elastic compression, adiabatic expansion, and the vertical background distribution. The amplitude and phase differences observed in different gases are explained on the basis of analyzing these components. It is shown how to use this effect in order to determine the wave propagation, the vertical displacement of the volume element, the wave frequency, and the spatial distribution of the wave energy density.     

大地震前体应变临震异常现象

本文对2011年1月至2014年4月间全球发生的80次MS≥7.0级地震前,二张营台和天堂河台Sacks体应变临震异常现象进行了研究,针对复杂震例提出了异常识别的前提条件。统计结果显示,体应变观测对震中距为8000km范围内的MS≥7.0级地震映震和前兆异常反映较好。同时,对异常现象进行了分类和描述,划分了三种异常类型：即固体潮畸变型、突变型和慢地震型,并对各种类型作了统计分析,进行了力学性质初步探讨。从研究结果来看,体应变异常信息对未来全球强震的发生具有一定的预示意义。     

大地震前体应变临震异常现象

本文对2011年1月至2014年4月间全球发生的80次MS≥7级地震前,二张营台和天堂河台Sacks体应变临震异常现象进行了研究,针对复杂震例提出了异常识别的前提条件。统计结果显示,体应变观测对震中距为8000km范围内的MS≥7级地震映震和前兆异常反映较好。同时,对异常现象进行了分类和描述,划分了三种异常类型:即固体潮畸变型、突变型和慢地震型,并对各种类型作了统计分析,初步探讨了力学性质。结果发现,体应变异常信息对未来大地震的发生具有一定的预示意义。     

Dynamics of the Development of Aluminum Monoxide Clouds in the Upper Atmosphere During the Launch of Solid-Propellant Rockets

Various mechanisms of the formation of AlO molecules during the operation of solid-propellant rocket engines in the upper atmosphere and processes of AlO glow decay are considered. The main contribution to AlO formation at altitudes of 120–200 km is made by the interaction of metallic aluminum contained in products of solid propellant combustion with atmospheric oxygen. The decrease in the brightness of AlO clouds is caused by a decrease in the AlO concentration as a result of cloud expansion due to diffusion processes and AlO oxidation with atomic oxygen.     

Some properties of flows in unsaturated soils with an exponential dependence of the hydraulic conductivity upon the pressure head

A systematic development of the consequences of an exponential dependence of the hydraulic conductivity upon the pressure head is presented. Alternative expressions for the flux are discussed in detail. For steady flows, partial differential equations in terms of the matric flux potential, the pressure head, and the total head are derived. For steady, plane and axially symmetric flows, partial differential equations for the stream function are given. A theoretical basis for the construction of viscous flow analogs for steady, plane and axially symmetric flows is also presented.