地面Sq磁场的分析和场向电流

地面Ｓｑ磁场的分析在一定程度上可揭示场向电流的存在。本文将Ｓｑ资料按１／２（夏－冬）的方法定性地显示了空间等效电流的分布。结果表明：在夏、冬季清晨由夏季半球流向冬季半球的场向电流特别明显，可是黄昏时的场向电流似乎不存在，踵时由冬季半球流向夏季半球的场向电流强度反而比清晨场向电流弱一些。     

我国中低纬度地区Sq焦点的分析与研究

本文利用１９８８年３月－１９８９年３月几次大的太阳活动期间我国９个台站的地磁资料，采用无穷大平板电流的等效电流体系方法，分析了我国中低纬度地区Ｓｑ焦点位置的变化特征，并对照ＫｐＤｓｔ，Ａｐ等指数给出了Ｓｑ焦点位置变化的合理解释。结构表明：（１）在不同的Ｋｐ指数段Ｓｑ焦点有不同的规律性，当Ｋｐ＜４时，随着Ｋｐ指数增大，Ｓｑ焦点向高纬方向移动；当Ｋｐ在４和６之间时，随着Ｋｐ指数增大，Ｓｑ焦点向低纬方向     

电离层S_q发电机理论的研究和数值模拟

本文回顾了近百年来（１８８９－１９９０）电离层发电机理论中Ｓｑ电流体系的研究进展，分别阐述了Ｓｑ电流体系的研究意义、获得Ｓｑ等效电流体系的正演和反演方法、给出了主要代表学者的研究成果及方法，并对Ｓｑ发电机理论存在的问题和需要进一步研究的课题进行了讨论，可以看出Ｓｑ等效电流体系研究虽然取得了很大进展，二维理论也在日渐完善，但三维发电机研究无论在理论上和计算方法上都还有改进的余地，如何最大程度上合理地解释Ｓｑ的变化规律，并与磁层物理和大气动力学联合起来综合考虑是今后三维理论工作所必须解决的问题。     

Sq外源和内源电流体系的经度效应和UT变化

根据ＩＧＹ／ＩＧＣ期间全球地磁台网以及中国地磁台站的资料，计算出每－ＵＴ小时的Ｓ_ｑ外源和内源电流体系．对Ｓ_ｑ电流体系ＵＴ变化和经度效应的分析研究表明，Ｓ_ｑ外源电流体系的空间图案没有显著的ＵＴ变化，电流涡焦点的地理纬度与磁赤道有密切关系，其变化范围，北半球为２５°－３５°Ｎ，南半球为３０°－４２．５°Ｓ．外源电流总强度的平均值为２２９ｋＡ（北半球）和１７３ｋＡ（南半球），其变化范围为±５０ｋＡ（北半球）和±４０ｋＡ（南半球）．Ｓ_ｑ内源电流体系的图案和强度有显著的ＵＴ变化，电流体系焦点纬度有类似于外源电流系的变化．在大西洋、印度洋、北太平洋地区，内源电流体系的总强度明显小于大陆地区的内源电流强度，表明这些大洋地区上地幔电导率低于大陆地区．     

地磁场Sq的经度效应和UT变化

使用国际地球物理年（ＩＧＹ）和国际地球物理合作年（ＩＧＣ）期间全球地磁台网的资料和中国台站的同期地磁记录，对地磁场太阳日变化Ｓ_ｑ的经度效应和ＵＴ变化进行了分析研究．将适用于瞬时全球磁场的球谐分析法与适用于平均场的双调和分析法相结合，提出了一种分析Ｓ_ｑ磁场的新方案，得到了（θ，Ｔ，ｔ）坐标系中组成Ｓ_ｑ场的三个部分，即仅随地方时ＬＴ变化的部分Ｓ_ＬＴ，仅随世界时ＵＴ变化的部分Ｓ_ＵＴ以及既随ＬＴ变化又随ＵＴ变化的部分Ｓ_ＬＵＴ．从全球来看，在ＩＧＹ／ＩＧＣ期间，这三部分的强度之比分别为：Ｘ分量１．０：０．２：０．３，ｙ分量１．０：０．１：０．６，Ｚ分量１．０：０．４：１．０．Ｓ_ｑ的经度效应和ＵＴ变化虽然表现了同一物理过程，但它们有不同的表达形式，其决定因素是地磁轴对地理轴的倾斜，地磁场的非偶极子成分（即区域性异常）和地球内部电性的横向不均匀性（包括海陆分布、地壳上地幔电导率的区域差异）     

极隙区场向电流对高纬电离层电场和电流体系的影响

用Ｋａｍｉｄｅ－Ｍａｔｓｕｓｈｉｔａ方法，在行星际磁场具有较小的北向分量，且｜Ｂｙ｜＞＞｜Ｂｋ｜时，对磁语和磁扰状态以及Ｂｒ＞０和Ｂｙ＜０等不同情况，分别计算了场向电流引起的电离层电势、电场和电流体系．结果表明，极隙区场向电流的存在使高纬向日面区域的电势发生畸变，当Ｂｙ＞０时，无论是磁扰还是磁静日，极隙区电场具有显著的北向分量；等离子体对流有较大的西向分量；电离层电流为东向电流．当Ｂｙ＜０时，电场和等离子体对流的方向与Ｂｙ＞０时相反；电离层电流在磁抗日有西向分量，但在磁静日没有西向分量．电导率对电场和电流体系的影响十分明显，磁扰极光带电导率增强使电流涡从背阳面向向阳而漂移，与静日相比，磁扰时极隙区场向电流引起的电场畸变更为明显，但电场和电流强度的大小却基本保持不变．     

行星际磁场By分量对地球磁层顶场向电流调制

采用三维可压缩MHD数值模拟研究了行星际磁场By分量的变化对磁层顶重联区场向电流大小和分布的影响. 行星际磁场通过模拟区x=-Lx处左边界条件By来影响重联过程，从而改变重联区的场向电流. 研究结果表明边界条件By的突然改变，能使重联区场向电流迅速增加，甚至达到增大一个量级的水平.By本身的存在(即不为零)也会使场向电流维持在一个较高的水平. 由于行星际磁场By分量不为零，而形成模拟区磁场By不对称分布，这种不对称分布是场向电流不对称分布产生的主要原因. 这些结果是与Orsted卫星最新观测结果和地 面观测结果相符合的，它表明行星际磁场By分量对地球空间场向电流有较大的调制作用.     

地球内磁层场向电流的统计特征

利用ISEE－1和ISEE-2飞船观测的磁场数据，分析了地球内磁层场向电流的统计特征，包括场向电流的空间（L值和地方时）分布；流进和流出电离层的场向电流随地方时的变化；场向电流发生率与地磁活动水平（以AL指数表征）、行星际磁场（IMF）Bz的关系，电流强度和密度随地磁活动水平的变化等．发现，场向电流大都发生在夜间，且集中在L为6-10区域内，场向电流发生率，强度和密度随地磁活动增强而增大，行星际磁场南向时的发生率远远高于北向时的发生率．这些结果表明，内磁层场向电流的产生是太阳风和磁层、电离层间电动耦合增加的结果．     

地磁静日Y分量季节变化的物理讨论

对电离层Ｅ层发电机Ｓｑ电流系和赤道区晨昏侧Ｆ层电流共同作用的地磁效应进行了定性分析和定量估计，并解释了静日地磁Ｙ分量日变化形态在冬、夏季近于反相的现象．所用物理机制能同样说明ＮｍａｘＦ２赤道异常驼峰每日出现、消失时间的季变化．     

赤道电射流的影响范围

本文收集了１９８２年３月印度、中国、菲律宾低纬地区９个地磁台的静日月均值资料。经分析对比后绘出了Ｓｑ（Ｈ），Ｓｑ（Ｚ）变幅与离磁赤道距离的关系图。结果显示赤道电射流对Ｓｑ（Ｚ）的影响可达５００ｋｍ，对Ｓｑ（Ｈ）的影响范围小于４００ｋｍ。这个结果与ＰＡＲＫＩＮＳＯＮ（１９８３）书中的论述基本一致。离磁赤道远达１０００ｋｍ的琼中台资料没受赤道电射流的影响，广州台资料则更不可能受影响。     

On the synchronism in the events within the core and on the surface of the earth: the changes in the organic world and in the polarity of the geomagnetic field in the phanerozoic

The data on geomagnetic reversals are compared with the changes in the organic world and with the lower-mantle plumes. The times of the formation of plumes and the times of their appearance on the Earth’s surface relate to the intervals characterized by the different frequencies of geomagnetic reversals, i.e., there is no interrelation between the formation of plumes and the frequency of the changes in the geomagnetic field polarity. At the same time, a certain synchronism is observed between the frequency of the geomagnetic reversals and the boundaries of the biostratigraphic ages, i.e., the changes in the organic world in the long-period range. A hypothesis is proposed, which explains the change in the sign of the geomagnetic field by the combined effect of the irregular rotation of the internal core relative to the mantle and the changes in the slope angle of the axis of the Earth’s rotation, which, in turn, results in synchronous events on the Earth’s surface: the rates of changes in the organic world.     

Comparison Between the Nutations of the Planet Mars and the Nutations of the Earth

The nutations of the planets Mars andEarth are investigated and compared. Alarge number of interior structureparameters are involved in the nutationcomputations. The comparison between the observations and the computationsprovides several constraints on these parmeters andtherefore allows a better understanding of the physics of the interior of theplanet. For the Earth, the high precision of the observations of the nutationshas led to a very good determination of interior properties of the planet. ForMars, observations of nutations are not yet available, and we review how theamplitude of the Martian nutations depends on the hypotheses consideredfor its interior. Although Mars is very similar to the Earth, its interior is not well known;for example, we don't knowif its core is liquid or solid. Only if the core is liquid,the Free Core Nutation (FCN) normal mode exists and can alter the nutationswhich are close to the resonance. From the observed geoids, it is known thatboth planets are not in hydrostatic equilibrium. The departure is larger forMars than for the Earth, and consequently, the implication of considering a convective mantle instead of a mantle in hydrostatic equilibrium described byClairaut's equation for the initial equilibrium state of the planet is largeron the Martian nutations than on the Earth nutations. The consequences of theuncertainty in the core dimensions are also examined and shown to be of a veryhigh influence for Mars if the core is liquid, due to the potential changes inthe FCN resonance. The influence of the presence of an inner core, which isknown to exist for the Earth, could be more important for Mars than for theEarth if the inner core is large. Due to the presence of Tharsis on Mars, thetriaxiality of this planet has, additionally, larger effects than on Earth.     

太平洋中部地磁台11年周期变化的研究

综合APIA、HONOLULU、PAMATAI 3个地磁台三分量的11年周期变化的形态后,可定性地提出该变化源于内场。如内源为核幔边界的电涡流,则其中心点应位于3台之间。     

On the Mechanism of the Secular Tidal Acceleration of the Solid Inner Core and the Viscosity of the Liquid Core

As is known, the secular deceleration of the Earth's diurnal rotation is explained mainly by the tidal friction in the ocean. Below we consider this mechanism in some detail, taking into account also elastic deformations of the mantle under the action of ocean loading and the interaction between the tide-generating body, ocean tidal wave, liquid outer core, and solid inner core. It is shown that elastic displacements of the core-mantle boundary under the action of ocean loading are of about the same amplitude and phase as the elastic loading displacements of the Earth's outer surface. As a result, side by side with the mechanism of secular deceleration of diurnal rotation of the mantle, there are also (1) the opposite mechanism of secular acceleration of diurnal rotation of the outer liquid core and of the solid inner core and (2) the mechanism of excitation of differential rotation in the liquid core. Taking these effects into account, we compare theoretical and modern observed data on the eastward drift of the solid inner core. It is shown that the best agreement may be obtained if the turbulent viscosity of the liquid core is about 2 × 10 ³ Poise     

On the use of the autocorrelation method for estimating the depth to the magnetic basement

The depth to the top of magnetic dykes can be estimated from total field aeromagnetic data using the relation between the depth to magnetic sources and the autocorrelation function of magnetic data. By using synthetic anomalies we show that in the ideal case, depth can be determined to an accuracy of 10% or better, when the anomaly sources are two-dimensional dykes. However, the estimated depths depend on the width of the dykes. The estimated depth is about 0.6 times the actual depth to the top of thin dykes, and around the true depth for thick dykes having width-to-depth ratio around 3. The depth is considerably overestimated for very thick dykes (e.g., contacts, which is a special case of the thick dyke). Thus, the autocorrelation method requires that the width-to-depth ratio of the dyke is estimated independently to correctly estimate the depths. Alternatively, it must be assumed that the width-to-depth ratio for the two-dimensional source body is between 1.5 and 4.     

固体潮的地震预测研究与地球动力学研究之分析比较

本文分析了现行固体潮地震研究中的历史影响,对比研究了固体潮地震预测研究和固体潮地球动力学研究二者在振动频率、振动源体积、传输距离与介质等方面的地球物理特点与本质区别,强调了固体潮地震预测研究中最根本的工作是建立地震预测的目标和基本概念.     

Macrobenthic communities of the Pechora Sea: the past and the present on the threshhold of the prirazlomnoye oil-field exploitation

On data of bottom sampling, carried out by means of grab, trawl and underwater photography in August–September of 1993 in the area of the Pechora Sea, quantitative regularities of macrobenthos distribution are described for the ecological monitoring purposes. Maps of -biodiversity and biomass indices, bottom communities and trophic zones, singled out by dominant method, are presented. Assessment of structure changes of the investigated area bottom communities during the last 60–70 years is fulfilled. It is shown that the described communities on the whole are of natural undisturbed character and that the revealed changes are within the natural fluctuations in the abundance of benthic populations or may be interpreted in terms of methodical differences in the data analysis and generalization by different authors.     

动水压力对深水桥墩地震响应影响的研究综述

地震激励下处于深水中的桥墩和周围水体的相互作用将对桥梁结构的动力响应产生较大影响。首先对地震作用下水-桥墩的相互作用理论做了概括,给出了动水压力对桥墩的作用效应及各自的适用范围;对主要的三种考虑流固耦合效应的分析方法做了对比,探讨了地震作用下影响水-结构相互作用的主要因素,并对今后的研究提出了建议。     

On the gravimetric undulations of the geoid and the deflections of the vertical

Summary The author mentions the aims of the World-wide gravity project he established in the Ohio State University in Columbus, in 1950. He outlines the practical procedure of the gravimetric computations of the undulationsN and the vertical deflection components and and emphasizes that only by the global international cooperation and additional gravity observations at sea carried out during the last decade it has been possible to gather to Columbus the needed gravity material. Since there exist still large gravimetrically unsurveyed areas it is of vital significance to study what gravity anomalies are best to be used for these regions. The given figures concerning the accuracy of theN, and , estimated theoretically and obtained in practice, indicate that in the gravimetrically well surveyed parts of the world like in Europe and the United States we can get gravimetrically on basis of existing gravity material theN-values with accuracy of about 5–10 meters, and and with the accuracy of about 1. The geoid undulationsN are already computed in Columbus for more than 6000 points of the northern hemisphere. The sample maps show the interesting geoid of Europe and vicinity between the latitudes 60° and 30° and longitude 5° W and 30° E, drafted on basis of more than 1000N-values computed at the corners of 1°×1° squares. It is interesting to realize that the geoid undulations in all this area are positive, the extreme values being between 40 and 50 meters. The geophysical significance of the geoid maps of this kind is pointed out.     

琼中地震台重力仪记录同震响应特征分析

2013年2月6-8日圣克鲁斯群岛发生6次强震,琼中地震台的重力仪记录都有同震响应出现。本文从重力仪记录的面波的延迟时间、最大变形幅度、同震持续时间3个方面研究了6次强震的同震响应特征。