各向同性与各向异性介质中地震波旅行时正演模拟与反演成像

By seismic tomography, interesting results have been achieved not only in the research of the geosphere with a large scale but also in the exploration of resources and projects with a small scale since 80'. Compared with traditional inversion methods, seismic tomography can offer more and detailed information about subsurface and has been being paid attention by more and more geophysicists. Since inversion based on forward modeling, we have studied and improved the methods to calculate seismic traveltimes and raypaths in isotropic and anisotropic media, and applied the improved forward methods to traveltime tomography. There are three main kinds of methods to calculate seismic traveltime field and its ray path distribution, which are ray-tracing theory, eikonal equation by the finite-difference and minimum traveltime tree algorithm. In ray tracing, five methods are introduced in the paper, including analytic ray tracing, ray shooting, ray bending, grid ray tracing and rectangle grid ray perturbation with three points. Finite-difference solution of eikonal equation is very efficient in calculation of seismic first-break, but is awkward in calculation of reflection traveltimes. We have put forward a idea to calculate traveltimes of reflected waves using a combining way of eikonal equation method and other one in order to improve its capability of dealing with reflection waves. The minimum traveltime tree algorithm has been studied with emphases. Three improved algorithms are put forward on the basis of basic algorithm of the minimum traveltime tree. The first improved algorithm is called raypath tracing backward minimum traveltime algorithm, in which not only wavelets from the current source but also wavelets from upper source points are all calculated. The algorithm can obviously improve the speed of calculating traveltimes and raypaths in layered or blocked homogeneous media and keep good accuracy. The second improved algorithm is raypath key point minimum traveltime algorithm in which traveltimes and raypaths are calculated with a view of key points of raypaths (key points of raypths mean the pivotal points which determine raypaths). The raypath key point method is developed on the basis of the first improved algorithm, and has better applicability. For example, it is very efficient even for inhomogeneous media. Another improved algorithm, double grid minimum traveltime tree algorithm, bases upon raypath key point scheme, in which a model is divided with two kinds of grids so that the unnecessary calculation can be left out. Violent undulation of curved interface often results in the phenomenon that there are no reflection points on some parts of interfaces where there should be. One efficacious scheme that curved interfaces are divided into segments, and these segments are treated respectively is presented to solve the problem. In addition, the approximation to interfaces with discrete grids leads to large errors in calculation of traveltimes and raypaths. Noting the point, we have thought a new method to remove the negative effect of mesh and to improve calculation accuracy by correcting the traveltimes with a little of additional calculation, and obtained better results.

攀西地区红格、新街岩体的岩石地球化学特征

The mafic-ultramafic layered intrusions in the Panxi, China contain large V-Ti-magnetite deposits. These layered intrusions are related with the Emeishan continental flood basalts in space and time. Two layered intrusions, Hongge and Xinjie have clear PGE mineralization at the base of the intrusions. Thus the detailed investigations of these two intrusions not only have a geological but also have an economic significance. This thesis aims to characterize the elemental and Sr-Nd isotopic features of diverse rock zones within the intrusion on the basis of systematic studies of the major, trace element and isotope ratios, therefore to constrain the petrogenesis, mantle source and evolution of the Hongge and Xinjie intrusions. Generally, both Hongge and Xinjie intrusions show the same Fe-Ti-rich and Si-M-poor characteristics. They are also enriched in rare-earth elements (REE) and large-ion lithophile elements (LILE) as well as in Sr-Nd isotope ratios (Hongge: initial Sr = 0.7056-0.7076, ε_(Nd)(t) and (Nd/Sm)_N-ε_(Nd)(t) plots, the Hongge intrusion has a similar elemental and isotopic features to the Emeishan low-Ti (LT) basalts, whereas the Xinjie intrusion was close to the Emeishan high-Ti (HT) basalt. Therefore, the Hongge intrusion may be co-genetic with the LT basalt, formed by the partial melting of the spinel-garnet transition mantle that had a slight enriched isotope character. In contrast, the Xinjie intrusion and the HT basalts are probably derived from the garnet-phases mantle with a primitive isotope character. The involvement of the components of mantle wedge into the source is considered to be the major reason of the REE and LILE enrichment and Nd isotope depletion in the Xinjie intrusion. In contrast with the systematic variations in TiO_2 content, Mg#, transition elements (Ni, Cu, Co), REE concentrations, and La/Yb, La/Sm ratios from the lower zone to upper zone, the different rock zones of the Hongge intrusion have no clear Sr-Nd isotope variations. This suggests that the Hongge intrusions were formed by the crystal fractionation from the same magma source. The rhythm may be formed by slow injection of the co-genetic magma during the crystal fractionation. The increase in K_2O and Al_2O_3 contents, REE abundance, and the degree of the REE fractionation in the base of the intrusion, together with the relatively low ε_(Nd)(t) value, may imply that the base of the Hongge intrusion was contaminated with the local crust rocks. Xinjie intrusion shows the clearly elemental and isotopic differences in diverse cumulus cycles. The observation of the systematic variations in TiO_2 content, Mg# value, transition elements (Ni, Cu, Co), REE concentrations, and La/Yb, La/Sm ratios in first cycle was not occurred in second cumulus cycle. In addition, the ε_(Nd)(t) value in second cumulus cycle is apparently higher than that of the first one. Thus the abruptly elemental and isotopic changes at the base of second cycle demonstrate that there is considerable new and depleted magma addition to the residue magma after the crystallization of the first cycle. These features are very similar to those of the well-known PGE-rich Bushveld and Stillwater layered intrusions. The PGE mineralization in Xinjie intrusion is much better than in Hongge intrusion. Therefore, the layered intrusion similar to the Xinjie in Panxi area posses the better prospects for the PGE deposits.

各向异性介质中的地震面波和S波分裂

Surface wave propagation in the anisotropic media and S-wave splitting in China mainland are focused in this M.S. dissertation. We firstly introduced Anderson parameters in the research of surface wave propagation in the anisotropic media were deduced, respectively. By applying the given initial model to the forward calculation of Love wave, we compared dispersion curves of Love wave in the anisotropic media with the one in the isotropic media. the results show that, although the two kind of results are similar with each other, the effect of anisotropy can not be neglected. Furthermore, the variation of anisotropy factors will result in the variation of dispersion curves, especially for high-mode one. The method of grid dispersion inversion was then described for further tectonic inversion. We also deduced inversion equation on the condition that the layered media is anisotropic, and calculated the phase-velocity partial derivatives with respect to the model parameters, P- and S-wave velocities, density, anisotropic parameters for Rayleigh wave and Love wave. Having analyzed the results of phase-velocity partial derivatives, we concluded that the derivatives within each period decreased with the depth increasing, the phase-velocity of surface wave is sensitive to the S-wave velocities and anisotropic factors and is not sensitive to the densities of layers. Dispersion data of Love wave from the events occurred during the period from 1991 to 1998 around the Qinghai and Tibet Plateau, which magnitudes are more than 5.5, have been used in the grid dispersion inversion. Those data have been preprocessed and analyzed in the F-T domain. Then the results of 1°*1° grid dispersion inversion, the pure path dispersion data, in the area of Qianghai and Tibet Plateau were obtained. As an example, dispersion data have been input for the tectonic inversion in the anisotropic media, and the results of anisotropic factors under the region of Qianghai and Tibet Plateau were initially discussed. As for the other part of this dissertation. We first introduced the phenomena of S-wave splitting and the methods for calculation the splitting parameters. Then, We applied Butterworth band-pass filter to S-wave data recorded at 8 stations in China mainland, and analyzed S-wave splitting at different frequency bands. The results show the delay time and the fast polarization directions of S-wave splitting depend upon the frequency bands. There is an absence of S-wave splitting at the station of Wulumuqi (WMQ) for the band of 0.1-0.2Hz. With the frequency band broaden, the delay time of S-wave splitting decreases at the stations of Beijing (BJI), Enshi (ENH), Kunming (KMI) and Mudanjiang (MDJ); the fast polarization direction at Enshi (ENH) changes from westward to eastward, and eastward to westward at Hailaer (HIA). The variations of delay time with bands at Lanzhou (LZH) and qiongzhong (QIZ) are similar, and there is a coherent trend of fast polarization directions at BJI, KMI and MDJ respectively. Initial interpretations to the results of frequency band-dependence of S-wave splitting were also presented.

中强地震震源的破裂过程

With the large developments of the seismic sources theory, computing technologies and survey instruments, we can model and rebuild the rupture process of earthquakes more realistically. On which earthquake sources' properties and tectonic activities law are realized more clearly. The researches in this domain have been done in this paper as follows. Based on the generalized ray method, expressions for displacement on the surface of a half-space due to an arbitrary oriented shear and tensile dislocation are also obtained. Kinematically, fault-normal motion is equivalent to tensile faulting. There is some evidence that such motion occurs in many earthquakes. The expressions for static displacements on the surface of a layered half-space due to static point moment tensor source are given in terms of the generalized reflection and transmission coefficient matrix method. The validity and precision of the new method is illustrated by comparing the consistency of our results with the analytical solution given by Okada's code employing same point source and homogenous half-space model. The computed vertical ground displacement using the moment tensor solution of the Lanchang_Gengma earthquake displays considerable difference with that of a double couple component .The effect of a soft layer at the top of the homogenous half-space on a shallow normal-faulting earthquake is also analyzed. Our results show that more seismic information would be obtained utilizing seismic moment tensor source and layered half-space model. The rupture process of 1999 Chi-Chi, Taiwan, earthquake investigated by using co-seismic surface displacement GPS observations and far field P-wave records. In according to the tectonic analysis and distributions of aftershock, we introduce a three-segment bending fault planes into our model. Both elastic half-space models and layered-earth models to invert the distribution of co-seismic slip along the Chi-Chi earthquake rupture. The results indicate that the shear slip model can not fit horizontal and vertical co-seismic displacements together, unless we add the fault-normal motion (tensile component) in inversions. And then, the Chi Chi earthquake rupture process was obtained by inversion using the seismograms and GPS observations. Fault normal motions determined by inversion, concentrate on the shallow northern bending fault from Fengyuan to Shuangji where the surface earthquake ruptures reveal more complexity and the developed flexural slip folding structures than the other portions of the rupture zone For understanding the perturbation of surface displacements caused by near-surface complex structures, We have taken a numeric test to synthesize and inverse the surface displacements for a pop-up structure that is composed of a main thrust and a back thrust. Our result indicates that the pop-up structure, the typical shallow complex rupture that occurred in the northern bending fault zone form Fengyuan to Shuangji, can be modeled better by a thrust fault added negative tensile component than by a simple thrust fault. We interpret the negative tensile distributions, that concentrate on the shallow northern bending fault from Fengyuan to Shuangji, as a the synthetic effect including the complexities of property and geometry of rupture. The earthquake rupture process also reveal the more spatial and temporal complexities form Fenyuan to SHuangji. According to the three-components teleseismic records, the S-wave velocity structure beneath the 59 teleseismic stations of Taiwan obtained by using the transform function method and the SA techniques. The integrated results, the 3D crustal structure of Taiwan reveal that the thickest part of crustal local in the western Central Range. This conclusion is consistent with the result form the Bouguer gravity anomaly. The orogenic evolution of Taiwan is young period, and the developing foot of Central Range dose not in static balancing. The crustal of Taiwan stays in the course of dynamic equilibrium. The rupture process of 2003)2,24,Jiashi, Xinjiang earthquake was estimated by the finite fault model using far field broadband P wave records of CDSN and IRIS. The results indicate that the earthquake focal is north dip trust fault including some left-lateral strike slip. The focal mechanism of this earthquake is different form that of earthquakes occurred in 1997 and 1998, but similar to that of 1996, Artux, Xinjiang earthquake. We interpreted that the earthquake caused trust fault due to the Tarim basin pushing northward and orogeny of Tianshan mountain. In the end, give a brief of future research subject: Building the Real Time Distribute System for rupture process of Large Earthquakes Based on Internet.

矾山杂岩体成因及其与磷（铁）矿的成矿关系

The Fanshan complex consists of layered potassic ultramafic-syenite intrusions. The Fanshan apatite (-magnetite) deposit occurs in the Fanshan complex, and is an important style of phosphorus deposit in China. The Fanshan complex consists of three (First- to Third-) Phases of intrusion, and then the dikes. The First-Phase Intrusive contains ten typical layered rocks: clinopyroxenite, biotite clinopyroxenite, coarse-grained biotite clinopyroxenite, pegmatitic orthoclase-biotite clinopyroxenite, variegated orthoclase clinopyroxenite, interstitial orthoclase clinopyroxenite, biotite rock, biotite-apatite rock, biotite rock and magnetite-apatite rock. This layered intrusive consists of nine rhythmic units. Each rhythmic unit essentially comprises a pair of layers: clinopyroxenite at the bottom and biotite clinopyroxenite at the top. The apatite (-magnetite) deposit is situated near the top of rhythmic Unit no. 6 of the First-Phase Intrusive. The Second-Phase Intrusive contains three typical rocks: coarse-grained orthoclase clinopyroxenite, . coarse-grained salite syenite and schorlomite-salite syenite. The Third-Phase Intrusive includes pseudo-trachytic salite syenite, porphyritic augite syenite, fine-grained orthoclase clinopyroxenite and fine-grained salite syenite. The origin of the Fanshan complex is always paid attention to it in China. Because most layered igneous intrusion in the world not only have important deposit in it, but also carry many useful information for studying the formation of the intrusion and the evolvement of magma. Two sketch maps were drawn through orebodies along no. 25 cross-cut on 425 mL and no. 1 cross-cut on 491 mL in the Fanshan mine. Through this mapping, a small-scaled rhythmic layering (called sub-rhythmic layering in the present study) was newly found at the top of the rhythmic Unit no. 6. The concept of sub-rhythmic layering is defined in this article. The sub-rhythmic layering is recognized throughout this apatite-rich part, except for magnetite-apatite rock. Presence of the layered magnetite-apatite rock is one of the characteristics of the Fanshan apatite (-magnetite) deposit. Thus, from this layer downwards six units of sub-rhythmic layering are recognized in the present study. Each unit consists of biotite clinopyroxenite (or biotite rock and biotite-apatite rock) layer at the bottom and apatite rock layer at the top. To study this feature in detail is an important work for understanding the origin of the Fanshan complex and apatite (-magnetite) deposit. The origin of the Fanshan complex and the relation of the formation of the apatite(-magnetite)deposit will be interpreted by the study of sub-rhythmic layering on the basis of previous research works. The magma formed the Fanshan complex was rich in K2O, early crystallized pyroxene, and after this phase more biotite crystallized, but no amphibole appeared. This indicated that the activity of H2O in the magma was low. Major element compositions of biotite and clinopyroxene (on thin sections) in the sub-rhythmic layering were analyzed using electron microprobe analyzer. The analytical results indicate Mg/(Mg+Fe*+Mn) atomic ratios (Fe*, total iron) of these two minerals rhythmically changed in sub-rhythmic layering. The trends of Mg/(Mg+Fe*+Mn) atomic ratio (Fe*, total iron) of biotite and clinopyroxene indicate that the magma evolved markedly from relatively magnesian bottom layer to less magnesian top layer in each sub-rhythmic unit. A general trend through the sub-rhythmic layering sequence is both minerals becoming relatively magnesian upwards. The formation temperatures for sub-rhythmic layering yield values between 600 and 800 ℃, were calculated using the ratio of Mg/(Mg+Fe+Mn) in the salite and biotite assemblage. The equilibrium pressures in the rhythmic layers calculated using the contents of Al in the salite were plotted in the section map, shown a concave curve. This indicates that the magma formed the First-Phase Intrusive crystallized by two vis-a-vis ways, from its bottom and top to its centre, and the magnetite-apatite rock was crytallized in the latest stage. The values of equilibrium pressures in the sub-rhythmic layering were 3.6-6.8(xlO8) Pa with calculated using the contents of Al in the salite. The characteristics of geochemistry in various intrusive rocks and the rocks or apatite of sub-rhythmic layers indicated that the Fanshan complex formed by the comagmatic crystallization. The contents of immiscible elements and REEs of apatite rock at the top of one sub-rhythmic unit are more than biotite clinopyroxenite at the bottom. The contents of immiscible elements and REEs of apatite of biotite clinopyroxenite at the bottom of one sub-rhythmic unit are higher than apatite rock at the top. The curves of rocks (or apatite) in the upper sub-rhythmic units are between two curves of the below sub-rhythmic unit in the primitive mantle-normalized trace element abundance spider diagram and the primitive mantle-normalized REE pattern. The trend for the contents of immiscible elements and REEs inclines to the same contents from the bottom to the top in sub-rhythmic layering. These characteristics of geochemistry of rocks or apatites from sub-rhythmic layering indicate that the latter sub-rhythmic unit was produced by the residual magma after crystallization of the previous sub-rhythmic unit. The characteristics of petrology, petrochemistry, geochemistry in the Fanshan complex and sub-rhythmic layers and the trends of Mg/(Mg+Fe+Mn) atomic ratio of biotite and clinopyroxene in sub-rhytmic layering rejected the hypotheses, such as magma immiscibility, ravitational settling and multiple and pulse supplement of magma. The hypothesis of differentiation by crystallization lacks of evidences of field and excludes by this study. On the base of the trends of formation temperatures and pressures, the characteristics of petrology, petrochemistry, geochemistry for the Fanshan complex and the characteristics of geochemistry for the rocks (or apatites), the trends of Mg/(Mg+Fe+Mn) atomic ratio of biotite and clinopyroxene in sub-rhytmic layering, and the data of oxygen, hydrogen, strontium and neodymium isotopes, this study suggests that the magma formed the Fanshan complex was formed by low degree partial melting of mantle at a low activity of H2O, and went through the differentiation at the depth of mantle, then multiply intruded and crystallized. The rhythmic layers of the First-Phase Intrusive formed by the magma fractional crystallized in two vis-a-vis ways, from the bottom and top to the centre in-situ fractional crystallization. The apatite (-magnetite) deposit of the Fanshan complex occurs in sub-rhythmic layering sequence. The the origin of the sub-rhythmic layering is substantially the origin of the Fanshan apatite (-magnetite) deposit. The magma formed the rhythmic layers of First-Phase Intrusive was rich in H2O, F and P at the later stage of its in-situ fractional crystallization. The Fanshan apatite (-magnetite) deposit was formed by this residual magma in-situ fractional crystallization. The magnetite-apatite rock was crystallized by two vis-a-vis ways at the latest stage in-situ fractional crystallization in the rhythmic layers. The result was light apatite layer below heavy the magnetite-apatite layer, formed an "inversion" phenomenon.

VSP克希霍夫法多波联合成像

Geophones being inside the well, VSP can record upgoing and downgoing P waves, upgoing and downgoing S waves simultaneously.Aiming at overcoming the shortages of the known VSP velocity tomography , attenuation tomography , inverse Q filtering and VSP image method , this article mainly do the following jobs:CD; I do the common-source-point raytracing by soving the raytracing equations with Runge-Kutta method, which can provide traveltime , raypath and amplitude for VSP velocity tomography , attenuation tomography and VSP multiwave migration.(D. The velocity distribution can be inversed from the difference between the computed traveltime and the observed traveltime of the VSP downgoing waves. I put forward two methods: A. VSP building-velocity tomography method that doesn't lie on the layered model from which we can derive the slowness of the grids' crunodes . B. deformable layer tomography method from which we can get the location of the interface if the layer's velocity is known..(3). On the basis of the velocity tomography , using the attenuation information shown by the VSP seismic wave , we can derive the attenuation distribution of the subsurface. I also present an algorithm to solve the inverse Q filtering problem directly and accurately from the Q modeling equation . Numerical results presented have shown that our algorithm gives reliable results . ?. According to the theory that the transformed point is the point where the four kinds of wave come into being , and where the stacked energy will be the largest than at other points . This article presents a VSP multiwave Kirchhoff migration method . Application on synthetic examples and field seismic records have shown that the algorithm gives reliable results . (5). When the location of the interface is determined and the velocity of the P wave and S wave is known , we can obtain the transmittivity and reflection coefficient 5 thereby we can gain the elastic parameters . This method is also put into use derive good result.Above all, application on models and field seismic records show that the method mentioned above is efficient and accurate .

工程地质三维可视化技术及其工程应用研究

Study of 3D visualization technology of engineering geology and its application to engineering is a cross subject which includes geosciences, computer, software and information technology. Being an important part of the secondary theme of National Basic Research Program of China (973 Program) whose name is Study of Multi-Scale Structure and Occurrence Environment of Complicated Geological Engineering Mass(No.2002CB412701), the dissertation involves the studies of key problems of 3D geological modeling, integrated applications of multi-format geological data, effective modeling methods of complex approximately layered geological mass as well as applications of 3D virtual reality information management technology.The main research findings are listed below:Integrated application method of multi-format geological data is proposed,which has solved the integrated application of drill holes, engineering geology plandrawings, sectional drawings and cutting drawings as well as exploratory trenchsketch. Its application can provide as more as possible fundamental data for 3Dgeological modeling.A 3D surface construction method combined Laplace interpolation points withoriginal points is proposed, so the deformation of 3D model and the crossing error ofupper and lower surface of model resulted from lack of data when constructing alaminated stratum can be eliminated.3D modeling method of approximately layered geological mass is proposed,which has solved the problems of general modeling method based on the sections or points and faces when constructing terrain and concordant strata.The 3D geological model of VII dam site of Xiangjiaba hydropower stationhas been constructed. The applications of 3D geological model to the auto-plotting ofsectional drawing and the converting of numerical analysis model are also discussed.3D virtual reality information integrated platform is developed, whose mostimportant character is that it is a software platform having the functions of 3D virtualreality flying and multi-format data management simultaneously. Therefore, theplatform can load different 3D model so as to satisfy the different engineeringdemands.The relics of Aigong Cave of Longyou Stone Caves are recovered. Thereinforcement plans of 1# and 2# cave in phoenix hill also be expressed. The intuitiveexpression provided decision makers and designers a very good environment.The basic framework and specific functions of 3D geological informationsystem are proposed.The main research findings in the dissertation have been successfully applied to some important engineering such as Xiangjiaba hydropower station, a military airport and Longyou Stone Caves etc.

下扬子北缘前陆盆地形成演化与油气赋存条件

The foreland basin on the northern margin of the lower reach of the Yangtze river (the lower Yangtze foreland basin) is tectonically situated in the basin-mountain transitional area along the southeastern flank of the Dabie mountains. The early formation and development of the basin is closely related to the open-up of the Mian-Lue paleo-oceanic basin on the southern margin of the Central Orogenic System represented by Qinling-Dabei orogenic belt, while the tectonic evolution of the middle-late stage of the basin is mainly related to development of the Mian-Lue tectonic zone that occurred on the basis of the previous Mian-Lue paleo-suture. The foreland basin of the northern rim of the lower reach of the Yangtze river was formed during the middle-Triassic collision between the Yangtze and North China plates and experienced an evolution of occuirence-development-extinction characterized by marine facies to continental facies and continental margin to intracontinent in terms of tectonic setting.The foreland basin (T2-J2) was developed on the basis of the passive continental marginal basin on the south side of the Mian-Lue paleo-ocean and superimposed by late Jurassic-Tertiary fault basin. The tectonic setting underwent a multiple transformation of rifting-collisional clososing-tensional faulting and depression, which resulted in changes of the property for the basin and the final formation of the superposed compose basin in a fashion of 3-story-building. According to the tectonic position and evolution stages of plate collision happening on the southeastern margin of the Dabie mountains, and tectono-tratigraphic features shown by the foreland basin in its main formational period, the evolution of the foreland basin can be divided into four stages: 1) pre-orogenic passive margin (P2-Ti). As the Mian-Lue ocean commenced subduction in the late-Permian, the approaching of the Yangtze and North China plates to each other led to long-periodical and large-scale marine regression in early Triassic which was 22 Ma earlier than the global one and generated I-type mixed strata of the clastic rocks and carbonate, and I-type carbonate platform. These represent the passive stratigraphy formed before formation of the foreland basin. 2) Foreland basin on continental margin during main orogenic episode (T2.3). The stage includes the sub-stage of marine foreland basin (T2X remain basin), which formed I-type stratigrphy of carbonate tidal flat-lagoon, the sub-stage of marine-continental transition-molasse showing II-type stratigraphy of marine-continental facies lake - continental facies lake. 3) Intracontinental foreland basin during intracontinental orogeny (Ji-2)- It is characterized by continental facies coal-bearing molasses. 4) Tensional fault and depression during post-orogeny (J3-E). It formed tectono-stratigraphy post formation of the foreland basin, marking the end of the foreland evolution. Fold-thrust deformation of the lower Yangtze foreland basin mainly happened in late middle-Jurassic, forming ramp structures along the Yangtze river that display thrusting, with deformation strength weakening toward the river from both the Dabie mountains and the Jiangnan rise. This exhibits as three zones in a pattern of thick-skinned structure involved the basement of the orogenic belt to decollement thin-skinned structure of fold-thrust from north to south: thrust zone of foreland basin on northern rim of the lower reach of the Yangtze river, foreland basin zone and Jiannan compose uplift zone. Due to the superposed tensional deformation on the earlier compressional deformation, the structural geometric stratification has occurred vertically: the upper part exhibits late tensional deformation, the middle portion is characterized by ramp fault -fold deformation on the base of the Silurian decollement and weak deformation in the lower portion consisting of Silurian and Neo-Proterozoic separated by the two decollements. These portions constitutes a three-layered structural assemblage in a 3-D geometric model.From the succession of the lower reach of the Yangtze river and combined with characteristics of hydrocarbon-bearing rocks and oil-gas system, it can be seen that the succession of the continental facies foreland basin overlies the marine facies stratigraphy on the passive continental margin, which formed upper continental facies and lower marine facies hydrocarbon-bearing rock system and oil-gas forming system possessing the basic conditions for oil-gas occurrence. Among the conditions, the key for oil-gas accumulation is development and preservation of the marine hydrocarbon-bearing rocks underlying the foreland basin. The synthetic study that in the lower Yangtze foreland basin (including the Wangjiang-Qianshan basin), the generation-reservoir-cover association with the Permian marine facies hydrocarbon-bearing rocks as the critical portion can be a prospective oil-gas accumulation.Therefore, it should aim at the upper Paleozoic marine hydrocarbon-bearing rock system and oil-gas forming system in oil-gas evaluation and exploration. Also, fining excellent reservoir phase and well-preserved oil-gas accumulation units is extremely important for a breakthrough in oil-gas exploration.

Efeito de sistemas de cultivo com cana-de-açúcar sobre a lixiviação dos herbicidas do grupo das triazinas em região de recarga do Aqüífero Guarani.

Algumas práticas agrícolas como o plantio direto pode afetar a lixiviação. Para estudar os efeitos desta prática, foi instalado um experimento de campo na área do Núcleo de Agronomia da Alta Mogiana, Instituto Agronômico de Campinas/Ribeirão Preto, de onde foram coletadas amostras de solos e água para estudos de herbicidas do grupo das triazinas: atrazina, simazina e ametrina. Foi instalado um experimento em área de cana colhida mecanicamente plantada com amendoim em diferentes sistemas de cultivo (plantio direto e plantio convencional) nas quais a cada 10 cm. foram retiradas amostras de solos até atingir 90 cm. Determinaram-se os seguintes parâmetros em laboratório: a) Densidade do solo, b) Porosidade total c) Microporosidade e d) Macroporosidade. Amostras de água coletada a cada três meses em poços da Prefeitura Municipal de Ribeirão Preto foram analisadas por GC-MS (cromatografia gasosa-espectrometria de massa). Não houve efeito dos sistemas de plantio na macro, micro e porosidade total. Houve apenas diferença significativa na densidade, sendo maior na camada superficial nos solos com plantio direto. Em todas as amostras de poços coletadas não foram detectados resíduos de triazinas, no limite de quantificação de 10 mg/L. Foram também reconstituídos os solos em colunas em laboratório e observou-se o movimento de atrazina e simazina no máximo até 20cm de profundidade. Não foi encontrado nenhum herbicida abaixo dos 20 cm. Para melhor entender os resultados, foi utilizado o simulador CMLS-94 "Chemical Movement in Layered Soils" e observou-se também que praticamente não houve diferença entre os resultados obtidos pelas simulações realizadas para plantios direto e convencional com relação à lixiviação das triazinas e que os valores de simulação indicaram que os produtos alcançam profundidades máximas de um metro, bem mais do que o encontrado nas colunas em laboratório.

Supporting Reuse and Evolution in Software Design

Program design is an area of programming that can benefit significantly from machine-mediated assistance. A proposed tool, called the Design Apprentice (DA), can assist a programmer in the detailed design of programs. The DA supports software reuse through a library of commonly-used algorithmic fragments, or cliches, that codifies standard programming. The cliche library enables the programmer to describe the design of a program concisely. The DA can detect some kinds of inconsistencies and incompleteness in program descriptions. It automates detailed design by automatically selecting appropriate algorithms and data structures. It supports the evolution of program designs by keeping explicit dependencies between the design decisions made. These capabilities of the DA are underlaid bya model of programming, called programming by successive elaboration, which mimics the way programmers interact. Programming by successive elaboration is characterized by the use of breadth-first exposition of layered program descriptions and the successive modifications of descriptions. A scenario is presented to illustrate the concept of the DA. Technques for automating the detailed design process are described. A framework is given in which designs are incrementally augmented and modified by a succession of design steps. A library of cliches and a suite of design steps needed to support the scenario are presented.

Post-grafting preparation of large-pore mesoporous materials with localized high content titanium doping

A new post-grafting process, consisting of two steps of substrate preparation and sol - gel post-grafting, has been developed to prepare titanium-doped mesoporous SBA-15 material with a double-layered structure and locally concentrated titanium content at the inner pore surface. With this novel technique, the single phased and originally ordered mesostructures can be well conserved; in the conventional direct synthesis they can be partially damaged when the frameworks are doped with high content heteroatoms. Titanium species exist in an isolated, tetrahedral structure and are localized at the pore surface; this is beneficial to both reactant access and product release. Characterization with XRD, N-2 adsorption/desorption isotherms, HREM/ EDS, ICP, UV - Vis, and the newly developed UV - Raman spectroscopy confirm these results. Preliminary catalytic tests with the selective epoxidation of cyclohexene show good catalytic activity. Among them, sample TiSBA-15-10 with a Si : Ti molar ratio of 10 shows a TON value of 75 and a highest product ( epoxide) yield of 55%.

Li+ Diffusion and its Structural Basis in the Nanocrystalline and Amorphous Forms of Two-dimensionally Ion-conducting LixTiS2

Winter, Rudolf; Heitjans, P., (2001) 'Li+ Diffusion and its Structural Basis in the Nanocrystalline and Amorphous Forms of Two-dimensionally Ion-conducting LixTiS2', Journal of Physical Chemistry B 105(26) pp.6108-6115 RAE2008

Holocaust w powieści Wasilija Grossmana "Życie i los"

Tematem artykułu jest książka bezpośrednio nie zaliczana do literatury Holocaustu, wybitna powieść Życie i los, rosyjskiego pisarza i dziennikarza Wasilija Grossmana, który dziś uznawany jest za jednego z najważniejszych twórców rosyjskich XX wieku. Życie i los okazuje się przykładem ujęcia dramatu Shoah na tle wojny jako części wielkiej Historii poddanej szaleństwom ideologii i polityki nazistów oraz terroru i rosnącego z drugiej strony antysemityzmu w państwie bolszewickim. Jednocześnie Zagłada pozostaje w tym utworze przede wszystkim tragedią konkretnych osób, widziana w porządku pojedynczej ludzkiej egzystencji, która nie daje się nigdy całkowicie sprowadzić do tego, co bezosobowe i masowe. Indywidualna perspektywa humanizuje obraz historii, ale też i go podważa w jego ogólnych strukturach i narracjach. Artykuł opisuje elementy, które składają się na żydowski wątek utworu. Dla jego odczytania ważny okazuje się szerszy kontekst biografii Grossmana i historia powstania oraz wydania powieści Życie i los. Jak widać – rosyjski pisarz dokonał dwóch znaczących gestów w odniesieniu do problemu reprezentacji Zagłady: z jednej strony zwrócił się ku konwencjom literackim, wykorzystał epicki rozmach, kompozycję wielowątkową i panoramiczne ujęcia wraz z ich koncepcją realizmu, wehikularności słowa, a jednocześnie wyszedł poza estetyczne ramy tekstu literackiego, wprowadził elementy lirycznych opisów i autobiograficzne akcenty oraz podkreślił etyczny wymiar całości – jako formy pamięci o tych niezliczonych ofiarach nie tylko Zagłady, ale i każdego XX wiecznego totalitaryzmu.

STAIR: Practical AIMD Multirate Congestion Control

Existing approaches for multirate multicast congestion control are either friendly to TCP only over large time scales or introduce unfortunate side effects, such as significant control traffic, wasted bandwidth, or the need for modifications to existing routers. We advocate a layered multicast approach in which steady-state receiver reception rates emulate the classical TCP sawtooth derived from additive-increase, multiplicative decrease (AIMD) principles. Our approach introduces the concept of dynamic stair layers to simulate various rates of additive increase for receivers with heterogeneous round-trip times (RTTs), facilitated by a minimal amount of IGMP control traffic. We employ a mix of cumulative and non-cumulative layering to minimize the amount of excess bandwidth consumed by receivers operating asynchronously behind a shared bottleneck. We integrate these techniques together into a congestion control scheme called STAIR which is amenable to those multicast applications which can make effective use of arbitrary and time-varying subscription levels.

Smooth Multirate Multicast Congestion Control

A significant impediment to deployment of multicast services is the daunting technical complexity of developing, testing and validating congestion control protocols fit for wide-area deployment. Protocols such as pgmcc and TFMCC have recently made considerable progress on the single rate case, i.e. where one dynamic reception rate is maintained for all receivers in the session. However, these protocols have limited applicability, since scaling to session sizes beyond tens of participants necessitates the use of multiple rate protocols. Unfortunately, while existing multiple rate protocols exhibit better scalability, they are both less mature than single rate protocols and suffer from high complexity. We propose a new approach to multiple rate congestion control that leverages proven single rate congestion control methods by orchestrating an ensemble of independently controlled single rate sessions. We describe SMCC, a new multiple rate equation-based congestion control algorithm for layered multicast sessions that employs TFMCC as the primary underlying control mechanism for each layer. SMCC combines the benefits of TFMCC (smooth rate control, equation-based TCP friendliness) with the scalability and flexibility of multiple rates to provide a sound multiple rate multicast congestion control policy.