塔里木盆地塔中—巴楚地区早二叠世岩浆岩地球化学特征及其成因

Tazhong-Bachu region is located in the Western Tarim basin.The early Permian magmatic rocks occur in the earth surface of Tazhong-Bachu region are mainly distributed in Kepintag,Mazhartag and Wajilitag region. There are a lot of wells, in which researchers found the early Permian magmatic rocks,in desert cover area.Most magmatic rocks are basic rocks, a few of which are ultrabasic rocks and intermediate-acid magmatic rocks.The ultrabasic rocks are are mainly occur in the Cryptoexplosive Breccia Pipes ,which is located in the volcanic complex body of Wajilitag region.The basic rocks can be divided into three rock types：The first type of the magmatic rocks in Tazhong-Bachu region is volcanic rock ,which occurs in the Lower Permian Kupukuziman Formation and Kaipaizileike Formation. Most Volcanic rocks are basalts,a few of which are volcanic breccias and pyroclastic rocks.The basalts are distributed in stratiform occurrences and interbeded the clastic rocks in Kepintag region.The attitudes of the basalts are nearly horizontal.Columnar Joints, gas pore textures and amygdaloidal structure are to develop in basalts.The second type of the magmatic rocks in Tazhong-Bachu region is diabase,which occurs in Mazhartag region.Diabase dike swarms occur in the stratums of Silurian, Devonian, Carboniferous and Lower Permian.They make from NNW direction to SSE direction, the obliquity of stratum is greater than 60°, and the dike thickness is form several cm to several meters. Diabasic texture is found in the rocks .The first type of the magmatic rocks in Tazhong-Bachu region are gabbro- pyroxenite rocks ,which occur in the Wajilitag igneous complex body. The intermediate-acid magmatic rocks, which are mainly syenites, are located in Mazhartag and Wajiltag region. But they are small in the whole Tazhong-Bachu region.There are intermediate-acid magmatic rocks,which are mainly dacite,in the northeast part of the wells in Tazhong-Bachu region.But ,it is not found in earth surface.Through systematical geochemical research of early Permian magmatic rocks,which are distributed in Kepintag,Mazhartag, Wajilitag region and the wells such as F1 well、Z1 well、Z13 well、TZ18 well、H3 well、H4 well et al., the focus on the geochronologic characteristics, the main element,trace element and REE geochemistry, the mineralogic characteristics, the Sr-Nd and Pb isotopic characteristics are put forward. The main points are: 1、A combined study of CL imaging and LA-ICP-MS U-Pb dating were carried out for zircon grains of the magmatic rocks in the Tazhong-Bachu region from the Tarim basin.The results of the systematic zircon LA-ICP-MS U-Pb dating reveal 272±6Ma to 291±10Ma for the magamatic rocks. It indicated that Early Permian is an important period of magmatic acvivity in the Tazhong-Bachu region. 2、There are a big hunch in the curves of primitive mantle-normalized trace element concentrations in the early Permian magmatic rocks from Kepintag, Mazhartag, Wajilitag region and the 14 wells. Light rare earth elements are comparatively rich and heavy rare earth elements are comparatively poor. The slope rates are same between light rare erath elements and heavy rare earth elements. It is not like the curves of the basalts in the convergent margin of plate , in which the slope rates of light rare erath elements is bigger than the alope rates of heavy rare erath elements, and the curves of heavy rare earth elements are comparatively flat. The magmatic rocks of Tazhong-Bachu region rarely have the characteristics of the basalts in the convergent margin of plate, which is that Tantalum, Niobium and Titanium are much poor, and Zirconium, Hafnium and Phosphorus are moderately poor. The magamatic rocks are mostly alkaline, which is indicated by the dots of the (Na2O+K2O)-SiO2 identification diagram. All of these indicate that the early Permian magmatic rocks were formed in an extension environment of intraplate. 3、The Thorium abundance is high and Tantalum abundance is low in most magmatic rocks from Tazhong-Bachu reguion, which is formed for crustal contamination.In the Th/Yb-Ta/Yb identification diagram，most dots are in the region, which means active continental margin, but a few dots are in the region, which means mantle source. It indicated the feeding of continental crust materials. 4、The magnesium content of the olvines from Wagilitag region is richest, and the olvines from Kepintag region is poorest in the tree region. 5、Through the the Sr-Nd and Pb isotopic study of the basalts and diabases from the F1 well core, Z1 well core, Z13 well core,TZ18 well core, and the basalts，gabbros, diabases(diabase-prophyrites) and pl-peridotites from Kepintag,Mazhartag, Wajilitag region , it indicated that all isotopic data is similar and close to enriched mantle.

Complex potentials and singular integral equation for curve crack problem in antiplane elasticity

Four types of the fundamental complex potential in antiplane elasticity are introduced: (a) a point dislocation, (b) a concentrated force, (c) a dislocation doublet and (d) a concentrated force doublet. It is proven that if the axis of the concentrated force doublet is perpendicular to the direction of the dislocation doublet, the relevant complex potentials are equivalent. Using the obtained complex potentials, a singular integral equation for the curve crack problem is introduced. Some particular features of the obtained singular integral equation are discussed, and numerical solutions and examples are given.

Large Eddy Simulation of Complex Turbulent Flows: Physical Aspects and Research Trends

In the current paper, we have primarily addressed one powerful simulation tool developed during the last decades-Large Eddy Simulation (LES), which is most suitable for unsteady three-dimensional complex turbulent flows in industry and natural environment. The main point in LES is that the large-scale motion is resolved while the small-scale motion is modeled or, in geophysical terminology, parameterized. With a view to devising a subgrid-scale(SGS) model of high quality, we have highlighted analyzing physical aspects in scale interaction and-energy transfer such as dissipation, backscatter, local and non-local interaction, anisotropy and resolution requirement. They are the factors responsible for where the advantages and disadvantages in existing SGS models come from. A case study on LES of turbulence in vegetative canopy is presented to illustrate that LES model is more based on physical arguments. Then, varieties of challenging complex turbulent flows in both industry and geophysical fields in the near future-are presented. In conclusion; we may say with confidence that new century shall see the flourish in the research of turbulence with the aid of LES combined with other approaches.

Multiscale Coupling in Complex Mechanical Systems

Multiscale coupling attracts broad interests from mechanics, physics and chemistry to biology. The diversity and coupling of physics at different scales are two essential features of multiscale problems in far-from-equilibrium systems. The two features present fundamental difficulties and are great challenges to multiscale modeling and simulation. The theory of dynamical system and statistical mechanics provide fundamental tools for the multiscale coupling problems. The paper presents some closed multiscale formulations, e.g., the mapping closure approximation, multiscale large-eddy simulation and statistical mesoscopic damage mechanics, for two typical multiscale coupling problems in mechanics, that is, turbulence in fluids and failure in solids. It is pointed that developing a tractable, closed nonequilibrium statistical theory may be an effective approach to deal with the multiscale coupling problems. Some common characteristics of the statistical theory are discussed.

Pattern Recognition With Weighted Complex Networks

In this paper we introduce a weighted complex networks model to investigate and recognize structures of patterns. The regular treating in pattern recognition models is to describe each pattern as a high-dimensional vector which however is insufficient to express the structural information. Thus, a number of methods are developed to extract the structural information, such as different feature extraction algorithms used in pre-processing steps, or the local receptive fields in convolutional networks. In our model, each pattern is attributed to a weighted complex network, whose topology represents the structure of that pattern. Based upon the training samples, we get several prototypal complex networks which could stand for the general structural characteristics of patterns in different categories. We use these prototypal networks to recognize the unknown patterns. It is an attempt to use complex networks in pattern recognition, and our result shows the potential for real-world pattern recognition. A spatial parameter is introduced to get the optimal recognition accuracy, and it remains constant insensitive to the amount of training samples. We have discussed the interesting properties of the prototypal networks. An approximate linear relation is found between the strength and color of vertexes, in which we could compare the structural difference between each category. We have visualized these prototypal networks to show that their topology indeed represents the common characteristics of patterns. We have also shown that the asymmetric strength distribution in these prototypal networks brings high robustness for recognition. Our study may cast a light on understanding the mechanism of the biologic neuronal systems in object recognition as well.

A high order accurate difference scheme for complex flow fields

A high order accurate finite difference method for direct numerical simulation of coherent structure in the mixing layers is presented. The reason for oscillation production in numerical solutions is analyzed, It is caused by a nonuniform group velocity of wavepackets. A method of group velocity control for the improvement of the shock resolution is presented. In numerical simulation the fifth-order accurate upwind compact difference relation is used to approximate the derivatives in the convection terms of the compressible N-S equations, a sixth-order accurate symmetric compact difference relation is used to approximate the viscous terms, and a three-stage R-K method is used to advance in time. In order to improve the shock resolution the scheme is reconstructed with the method of diffusion analogy which is used to control the group velocity of wavepackets. (C) 1997 Academic Press.

Complex stress functions and plastic zone sizes for notch cracks subjected to various loading conditions

In this paper, the conformal mapping method is used to solve the plane problem of an infinite plate containing a central lip-shaped notch subjected to biaxial loading at a remote boundary or a surface uniform pressure on the notch. The stress intensity factors KI and KII are obtained by the derived complex stress functions. The simple analytical expressions can be applied to the situation of cracks originating from a circular or an elliptical notch. The plastic zone sizes for such notch cracks are subsequently evaluated in light of the Dugdale strip yield concept. The results are consistent with available numerical data.

Complex Transition of Double-Diffusive Convection in a Rectangular Enclosure with Height-to-Length Ratio Equal to 4: Part I

This is the first part of direct numerical simulation (DNS) of double-diffusive convection in a slim rectangular enclosure with horizontal temperature and concentration gradients. We consider the case with the thermal Rayleigh number of 10^5, the Pradtle number of 1, the Lewis number of 2, the buoyancy ratio of composition to temperature being in the range of [0,1], and height-to-width aspect ration of 4. A new 7th order upwind compact scheme was developed for approximation of convective terms, and a three-stage third-order Runge-Kutta method was employed for time advancement. Our DNS suggests that with the buoyancy ratio increasing form 0 to 1, the flow of transition is a complex series changing fromthe steady to periodic, chaotic, periodic, quasi-periodic, and finally back to periodic. There are two types of periodic flow, one is simple periodic flow with single fundamental frequency (FF), and another is complex periodic flow with multiple FFs. This process is illustrated by using time-velocity histories, Fourier frequency spectrum analysis and the phase-space rajectories.

MODIFIED DIRECT TWOS-COMPLEMENT PARALLEL ARRAY MULTIPLICATION ALGORITHM FOR COMPLEX MATRIX OPERATION

A direct twos-complement parallel array multiplication algorithm is introduced and modified for digital optical numerical computation. The modified version overcomes the problems encountered in the conventional optical twos-complement algorithm. In the array, all the summands are generated in parallel, and the relevant summands having the same weights are added simultaneously without carries, resulting in the product expressed in a mixed twos-complement system. In a two-stage array, complex multiplication is possible with using four real subarrays. Furthermore, with a three-stage array architecture, complex matrix operation is straightforwardly accomplished. In the experiment, parallel two-stage array complex multiplication with liquid-crystal panels is demonstrated.

Three-dimensional superresolution by three-zone complex pupil filters

Complex pupil filters are introduced to improve the three-dimensional resolving power of an optical imaging system. Through the design of the essential parameters of such filters, the transmittance and radius of the first zone, three-dimensional superresolution is realized. The Strehl ratio and the transverse and axial gains of such filters are analyzed in detail. A series of simulation examples of such filters are also presented that prove that three-dimensional superresolution can be realized. The advantage of such filters is that it is easy to realize three-dimensional superresolution, and the disadvantage is that the sidelobes of the axial intensity distribution are too high. But this can be overcome by the application of a confocal system. (C) 2005 Optical Society of America.

One-shot parallel complex Fourier-domain optical coherence tomography using a spatial carrier frequency

We propose a novel method of one-shot parallel complex Fourier-domain optical coherence tomography using a spatial carrier frequency for full range imaging. The spatial carrier frequency is introduced into the 2-D spectral interferogram in the lateral direction by using a tilted reference wavefront. This spatial-carrier- contained 2-D spectral interferogram is recorded with one shot of a 2-D CCD camera, and is Fourier-transformed in the lateral direction to obtain a 2-D complex spectral interferogram by a spatial-carrier technique. A full-range tomogram is reconstructed from the 2-D complex spectral interferogram. The principle of this method is confirmed by cross-sectional imaging of a glass slip object. (c) 2008 Society of Photo-Optical Instrumentation Engineers.

Comparison between complex amplitude envelope representation and complex analytic signal representation in studying pulsed Gaussian beam

Analytic propagation expressions of pulsed Gaussian beam are deduced by using complex amplitude envelope representation and complex analytic signal representation. Numerical calculations are given to illustrate the differences between them. The results show that the major difference between them is that there exists singularity in the beam obtained by using complex amplitude envelope representation. It is also found that singularity presents near propagation axis in the case of broadband and locates far from propagation axis in the case of narrowband. The critical condition to determine what representation should be adopted in studying pulsed Gaussian beam is also given. (C) 2004 Elsevier B.V. All rights reserved.

Laser-induced changes on the complex refractive indices of phase-change thin film

The refractive indices of crystalline phase-change films are usually obtained by thermal-induced crystallization. However, this is not accurate, because the crystallization of phase-change film in rewritable optical disks is laser induced. In this study, we use the initializer to crystallize the phase-change films. The dependence of the refractive index n and the extinction coefficient k of the phase-change films on the initialization conditions are studied. Remarkable changes of the refractive indices (especially k) are found when the initialization laser power density is 6.63 mW/mum(2) and the initialization velocity is 4.0 m/s. At the same time, the structure changes of the phase-change films are also studied. This dependence is explained by the structure change of the films. These results are significant in improving the accuracy of optical design and the thermal simulation of phase-change optical disks, as well as in the study of phase-change optical disks at shorter wavelengths. (C) 2003 Society of Photo-Optical Instrumentation Engineers.