祁连与北秦岭结合部位陇山岩群与秦岭岩群对比讨论

发育于陇山地区 (祁连山 )的变质基底岩系—陇山岩群 ,其岩石组合、原岩建造、岩石化学、地球化学、变质作用及构造环境与北秦岭造山带秦岭岩群非常相似 ,属同一大地构造带 ;被后期构造改造位错形成现在状态     

Geochronology of the Karadere basement (NW Turkey) and implications for the geological evolution of the Istanbul zone

Earlier geological work in the Istanbul zone, western Pontide tectonic belt, has revealed the presence of extensive basement outcrops exposed underneath Palaeozoic and Mesozoic to Tertiary cover sequences. The basement of suspected Neoproterozoic age plays an important role in understanding the crustal accretion process in NW Turkey. We report the first results of a detailed Pb-Pb and U-Pb zircon study complemented by Nd-Sr whole rock and mineral data from basement rocks exposed in the Karadere valley, Safranbolu area. Five samples were selected for this study, comprising three metagranitoids and two metasediments. Zircon geochronology indicates that the metagranitoids were formed during Late Proterozoic pan-African magmatic events between 590 and 560 Ma. The rocks are of tonalitic and granitic composition and have low Nb/Y ratios and Ti contents, consistent with those of arc rocks. A continental arc setting is supported by their Sr and Nd isotope data that indicate a contribution of a mantle source as well as crustal assimilation during magma genesis. The metasediments can clearly be distinguished from the metagranitoids by their higher ⁸⁷Sr/⁸⁶Sr ratios and lower )_Nd-values at 580 Ma, which supports the suggestion that the arc was underlain by mature continental crust. Zircons from the metasediments yield a range of Pb-Pb ages between 1,860 and 710 Ma. Thirty per cent of them fall between 890 and 710 Ma, possibly suggesting a derivation from Gondwana (Afro-Arabian) regions. A Sm-Nd garnet-whole rock analysis obtained on a metagranite gives an age of 559NJ Ma, which either reflects pre-metamorphic magmatic growth of garnet in a felsic melt or a syntectonic high-temperature metamorphic event. Uplift and cooling of the basement is further constrained by Rb-Sr biotite ages of 548-545 Ma. These lower Cambrian mineral ages demonstrate that the Istanbul zone was not thermally reactivated during the Hercynian, Cimmerian or Alpine orogeny, in contrast to its neighbouring tectonic zones, confirming its role as a suspect terrane in the modern western Pontide tectonic belt.     

Consistent formulation of direct and substructure methods in nonlinear soil-structure interaction

Both direct and substructure methods of dynamic soil-structure interaction analysis can be treated using a common analytical model with difference being restricted only to the definition of boundary conditions of the bounded soil zone. It is shown that a consistent formulation of the problem equally applicable to both methods can be achieved in which true nonlinear behaviour of the bounded soil zone (near-field) can be taken into account in the time domain through properly defined constitutive models. However, for the linear boundary conditions to be imposed on the near-field inevitably involves the application of the principle of superposition resulting in a linear far-field approximation. Therefore, the bounded soil zone taken should be large enough in both methods to reduce the adverse effects of the far-field linearization.     

The dynamic foundation interaction of multistorey frames

This paper discusses the extent to which foundation properties influence the response of some framed structures to earthquakes. Three stages can be isolated, the first of which checks the validity of a theoretical method by means of model studies. Five models were made, a five-storey plane frame rigidly fixed at its feet, two models of the same frame but now in association with a linearly elastic isotropic foundation, Adiprene L-100 and L-167, which had E-values of 4.4 and 39.7 N/mm², respectively. A five-storey, asymmetric space frame was also made, with fixed feet and with a foundation of modulus 4.4 N/mm². In this first stage, resonance tests were made, using the MAMA,² to obtain frequencies, mode shapes and damping values. Corresponding frequencies and mode shapes were calculated using a finite element idealization. The second stage uses a proven computer program for a parametric study to obtain a large number of results, which give a good indication of the effect of different foundation conditions on this type of structure. Some calculations are also made in which the foundation is represented by equivalent springs⁸ instead of finite elements. In the third stage dynamic response was considered. A shaking table was built on which the models were subjected to a number of actual earthquake records, which had been suitably scaled and recorded on magnetic tape. The structural response was measured, and compared with calculated values obtained by step-by-step methods and, alternatively, the modal addition approach. For the asymmetric space-frame, particular attention was paid to the torsional effect.     

A linear mathematical model for the seismic inplane behaviour of brick masonry walls part 1: Theoretical considerations

In this study two mathematical models are presented for the linear dynamic behaviour of masonry walls. The study is completed in three stages: experimental observations, selection of a mathematical model and the determination of model parameters through optimization analysis. In the present paper (Part 1) the theoretical analysis used in the development of the mathematical models is presented. Part 2 is devoted to the optimization analysis. Evaluation of the experimental data, which is described in detail in Part 2, indicates that the first two modal frequencies of the wall specimen are close to each other. This may be attributed, on physical grounds, to strong interaction between the brick and mortar phases of the wall. Accordingly, a two-phase mathematical model, namely a mixture model (MM), is chosen to describe the wall behaviour because it can differentiate between the two phases of the wall and take into account the interaction between them. The equations of MM are put into a discrete form to simplify the optimization analysis. As a special case, MM contains a simple one-phase model called the effective modulus model (EMM). The equations of EMM are also established. Finally, the theoretical complex frequency response functions (CFRF) predicted by MM and EMM are obtained. CFRF relates the top acceleration of the wall to its base acceleration and is the response quantity chosen to be matched in the optimization analysis.     

糖蜜酒精废液生化法的研究进展

介绍国内外糖蜜酒精废液生化法的研究现状 ,指出单级工艺很难达到排放标准 ,需要二段以上工艺才能使废液达标排放。     

The greatest soda-water lake in the world and how it is influenced by climatic change

Global wanning resulting from increasing greenhouse gases in the atmosphere and the local climate changes that follow affect local hydrospheric and biospheric environments. These include lakes that serve surrounding populations as a fresh water resource or provide regional navigation. Although there may well be steady water-quality alterations in the lakes with time, many of these are very much climate-change dependent. During cool and wet periods, there may be water-level rises that may cause economic losses to agriculture and human activities along the lake shores. Such rises become nuisances especially in the case of shoreline settlements and low-lying agricultural land. Lake Van, in eastern Turkey currently faces such problems due to water-level rises. The lake is unique for at least two reasons. First, it is a closed basin with no natural or artificial outlet and second, its waters contain high concentrations of soda which prevent the use of its water as a drinking or agricultural water source. Consequently, the water level fluctuations are entirely dependent on the natural variability of the hydrological cycle and any climatic change affects the drainage basin. In the past, the lake-level fluctuations appear to have been rather systematic and unrepresentable by mathematical equations. Herein, monthly polygonal climate diagrams are constructed to show the relation between lake level and some meteorological variables, as indications of significant and possible climatic changes. This procedure is applied to Lake Van, eastern Turkey, and relevant interpretations are presented.