The transition from people''s property to private property: Consequences of the restitution principle for urban development and urban renewal in East Berlin''s inner-city residential areas

The constitutional decision to return to their original owners all real-estate property in East Germany that had either been expropriated or placed under state administration (the restitution principle) has had significant consequences for urban development and urban renewal. Experiences from East Berlin's innercity residential areas illustrate the effects on the state of repair of housing, the character of residential neighbourhoods, the tenants living in the areas affected, and the future structure of real-estate ownership. The case studies reveal a picture of a contradictory development of residential neighbourhoods, including shifting power relations and new polarizations, especially between tenants and landlords.     

The Darwin Rise demise: the western Pacific guyot heights trace the trans-Pacific Mendocino fracture zone

The Darwin Rise has been proposed so many times and in so many forms and places that the time has come to make a more comprehensive examination of the region. Lying on the NW Pacific Plate between the Geisha Guyots, the Mid-Pacific Mountains, the equator, and the trenches, the region is roughly bounded by magnetic anomaly M20 (147 Ma). It was subjected to a massive outpouring of lava about 105 to 120 Ma, which created the guyots and seamounts in that region. Guyots are excellent tools for studying events of long ago because they eroded in the same lowstand in the Cretaceous and guyot relief, therefore, is a surrogate for paleo-sealevel. The relief is derived by subtracting the break depth of the summit plateau of a guyot from the regional depth. Guyot relief would necessarily be less in the center than to the periphery if the feature formed on a pre-existing rise, as has been postulated. The existence of a paleo-Darwin Rise would give concentric contours for the region in question. Of the sixty guyots used in this study, thirty-seven of these guyots were surveyed using SASS multibeam in the Marcus-Wake seamount group. Twenty-three guyots were surveyed using random track single-beam sonar surveys. An entirely different scenario is shown. Data revealed a major fracture passing through the area coevally or after the guyots formed. Because the depths to the summit are not the same now, vertical tectonics occurred after subaerial erosion. This means the fracture formed during and after the erosion (roughly 105 Ma) and influenced the normal sequence of events in guyot formation. Depending on how one deciphers trends through the Hess Rise morass, SASS bathymetry shows a continuation of the Surveyor/Mendocino fracture zone swarm inside the M20 region to the NE of these data. The fracture swarm continues to the western Pacific trench system. Based on this information, if the Darwin Rise ever existed, it had to have done so elsewhere.     

亚太地区经济区域化及其地理研究

本文针对亚太地区经济区域化发展趋势，阐明了该地区经济合作形式的主要特征，同时，对其进行地理研究的可行性及其意义提出自己的见解。     

Recovering magnetic susceptibility from electromagnetic data over a one-dimensional earth

While the inversion of electromagnetic data to recover electrical conductivity has received much attention, the inversion of those data to recover magnetic susceptibility has not been fully studied. In this paper we invert frequency-domain electromagnetic (EM) data from a horizontal coplanar system to recover a 1-D distribution of magnetic susceptibility under the assumption that the electrical conductivity is known. The inversion is carried out by dividing the earth into layers of constant susceptibility and minimizing an objective function of the susceptibility subject to fitting the data. An adjoint Green's function solution is used in the calculation of sensitivities, and it is apparent that the sensitivity problem is driven by three sources. One of the sources is the scaled electric field in the layer of interest, and the other two, related to effective magnetic charges, are located at the upper and lower boundaries of the layer. These charges give rise to a frequency-independent term in the sensitivities. Because different frequencies penetrate to different depths in the earth, the EM data contain inherent information about the depth distribution of susceptibility. This contrasts with static field measurements, which can be reproduced by a surface layer of magnetization. We illustrate the effectiveness of the inversion algorithm on synthetic and field data and show also the importance of knowing the background conductivity. In practical circumstances, where there is no a priori information about conductivity distribution, a simultaneous inversion of EM data to recover both electrical conductivity and susceptibility will be required.     

Invariants in toroidal and tangentially geostrophic frozen-flux velocity fields

We derive two new types of invariant that must be obeyed by the radial magnetic field at the core-mantle boundary if the hypothesis of frozen flux is valid and the fluid motion is either toroidal or tangentially geostrophic there. These general invariants incorporate specific invariants that are already known and can, in principle, be tested using magnetic data that cover an interval of time.     

Periodicity of magnetic intensities in magnetic anomaly profiles: the Cenozoic of the South Atlantic

Spectral analyses of several published magnetic anomaly profiles from Candé & Kent (1992a) were undertaken prior to analysing, in the same way, raw magnetic anomaly data from similar parts of the South Atlantic. It was found that similar and distinct medium and short wavelengths were present in both the published and raw data. When these are converted into the time domain using the average rate of spreading for each profile, these periodicities appear similar, possibly identical, to those expected from the long-term eccentricity orbital parameters (Fischer, DeBoer & Premoli Silva 1990). While such correlations are not necessarily causative, they suggest that magnetohydro-dynamical processes near the core-mantle boundary may be affected by gravitational changes due to planetary orbital perturbations.     

Three-dimensional Rayleigh hysteresis of oriented core samples from the German Continental Deep Drilling Program: susceptibility tensor, Rayleigh tensor, three-dimensional Rayleigh law

Rayleigh hysteresis, as defined by the well-known Rayleigh relations, has been observed not only when magnetization of pyrrhotite-bearing KTB-samples is measured in parallel to a weak dc magnetic field, but also in experiments where field and measuring directions have been adjusted strictly perpendicularly to each other. Nine-tupels of independent Rayleigh hysteresis loops could thus be compiled. Their characteristic coefficients X ^ijk of initial susceptibility together with the Rayleigh loss coefficients α^jk have been proved to determine completely the samples' weak-field magnetic anisotropy. Interpreting the coefficient matrices ( X ^ijk) and (α^jk) as the tensor of initial susceptibility and the Rayleigh tensor, respectively, generalization of the isotropic Rayleigh relations in terms of corresponding tensor relationships has been suggested for the anisotropic case. Application to the KTB samples showed 3-D Rayleigh hysteresis measurements to be an excellent tool for rock magnetic analysis in terms of ore content and crystalline texture. In particular, a magnetocrystalline double texture of the basal planes of pyrrhotite precipitates and their [1120] directions of easy magnetization have been clearly detected. Surprisingly, the welt-known theorem α= const. X ²_I, formulated by Néel (1942) for the isotropic case, has been found to hold true even in tensor generalization (α_jk) = const ( X ²_jk). To reach sufficient resolution for the measurements performed, a sensitive vibrating coil magnetometer (VCM) has been developed.     

覆盖层下三维异常体对垂直磁偶极源的电磁响应

针对地下半空间存在三维异常体及覆盖层情况，计算了垂直磁偶极子的场，计算结果表明σ１与σ２接近时，覆盖层影响减小；σ１增加时覆盖层影响增大；对于不同的σ２／σ１值，场幅值对高频（ｆ≥２ｋＨｚ）和低频（ｆ≤１０Ｈｚ）都明显减小，只有在２ｋＨｚ≥ｆ≥１０Ｈｚ之间，场幅值可达最大。还表明垂直磁偶极子的场具有较强的岩性识别和分层能力     

华北板块南缘栾川群研究

栾川群出露于东秦岭北部。在栾川群分布区域，古华北板块不同时代的地层往南逆冲，构成北秦岭的太华推覆体。栾川群存在于该推覆体内部的特定逆冲岩席之中，沿这一逆冲岩席追索，确定古华北板块南缘的栾川群是连续沉积的，而受后期推覆构造的改造，栾川群在推覆体前缘的分布是断续相连的。根据地层之间的接触关系、岩浆活动、沉积作用的研究，对栾川群的划分提出了新的看法，认为栾川群由三川组、南泥湖组、煤窑沟组及大红口组构成。栾川群形成于震旦纪晚期，由湖坪及潮下斜坡等滨浅海沉积物构成。栾川群的岩浆岩为具双众数特征的岩套，具典型的大陆裂谷岩浆岩特征。并认为中元古代以来，古华北板块南缘处于裂陷拉张环境。早期的裂陷形成了熊耳群、汝阳群、官道口群及竞坪群，晚期裂陷的过程形成了栾川群、陶湾群，其进一步发育导致以二郎坪群为代表的洋壳生成。     

利用相关分析划分重力异常

本文从理论上对相关分析法区分重力异常的可行性进行了论述，并从一元线性回归方程着手，对大地水准面上的重力值与相应的地形高程作了相关分析，通过分析，认为在区域性小比例主均衡补偿基本完善的条件下，重力值与高程有极好的线性相关关系；当计算窗口较大时，地下的局部不均匀体，不足以破坏重力值与高程的相头发一，所以，在实际工作中，利用相关分析处理重力资料的叠加场，可以收到较好的效果，且方法简单易行。