山西省界边缘地带旅游发展的经济学分析

文章拟从区域经济学、产业经济学、制度经济学的观点,对山西省界边缘地带旅游发展给予经济学分析。

景观空间创造——景观设计方法探讨

基于成都"和睦人家"三期住宅小区景观设计工程实践,提出景观设计的本质是空间设计,景观设计应结合工程项目具体的环境特征,对可感知边缘界、可感知区域、可见路径与节点等进行深入分析,理性的运用城市设计理论指导进行景观设计,这应该是居住区景观设计的原则和方法之一。

基于KSVM决策树法的人脸检测与定位

传统的SVM直接在线性条件下训练SVM分类器完成人脸与非人脸的分类,分类器训练困难,计算量大且速度慢。为构造一个复杂背景下人脸检测与定位的新方法,本文用核函数把SVM推广到非线性SVM,再与二叉树相结合,可以解决多类识别问题,此即KSVM决策树人脸检测方法。在此基础上,人脸面部特征被进一步确认。本文提出了改进的四边界Prewitt边缘算子提取人眼,进而定位五官。实验结果表明该方法检测率较高,虚警率较低,定位准确。

Carboniferous Alaskan-type complex along the Sino–Mongolian boundary,southern margin of the Central Asian Orogenic Belt

We present zircon ages and geochemical data for the Hongshishan Carboniferous Alaskan-type mafic–ultramafic complex exposed in the Beishan area along the Sino–Mongolian boundary, southern margin of the Central Asian Orogenic Belt. This complex mainly consists of dunite,harzburgite, lherzolite, wehrlite, and gabbro, which intrudes Early Carboniferous volcanic rocks and reveals a zoned structure. Zircons of a gabbro sample yielded a 206Pb/238 U age of 357 ± 4 Ma, reflecting the time of Early Carboniferous magmatism. Zircon ages were also obtained for an andesite(322 ± 3 Ma) and a basaltic andesite(304 ± 2 Ma).High initial Nd isotope whole-rock values suggest that the Hongshishan gabbro [e_(Nd(t))= +9.6-+10.2] and basalt[eNd(t)= +10.0-+10.8] were derived from a depleted mantle source. Slightly lower eNd(t)values for the ultramafic rocks [eNd(t)= +8.5-+8.7] suggest some interaction of the parental magma with the continental crust. In contrast, the Late Carboniferous Quershan samples in this area represent subduction-related arc volcanic rocks with Adakite-like compositions. The early Carboniferous Hongshishan Alaskan-type complex was interpreted to represent the remnants of a magma chamber that crystallized at the base of a mature island arc, whereas the Quershan island arc volcanic rockssuggest the resurrection of the subduction process after arccontinent collision and uplift of the roots of the arc.

Analysis of principle deviation of subpixel Zernike moments operator

In original Zernike moments subpixel edge operator, ideal step edge model is chosen for calculating four parameters of a pixel point, and therefore principle deviation is caused by edge model. In order to discuss the effect of principle deviation on edge location, sampled edge model is chosen for calculating edge parameters, principle deviation of edge translation l is derived based on Zernike moments edge detection theory, and modified formula of l is given for Zernike moments operator with masks of 5×5 size. Both theory analysis and testing result demonstrate that principle deviation is zero when edge translation l is limited in central pixel of a sampled window. In another case, the modification of l should be considered, which results in edge location accuracy of non-subpixel level for this subpixel edge operator.

Stress field near an interface edge of linear hardening materials

The elastic-plastic singular stress field near an interface edge of bounded linear hardening material is substantially as same as that of bonded elastic materials whose Young' s modulus and Poisson ratio are substituted by equivalent values, respectively. Further investigation by the elasto-plastic boundary element method (BEM) on the stress field near the interface edge showed that the stress field there can be divided into three regions: the domain region of the elastic-plastic singular stress field, the transitional region and the elastic region. The domain region of the elastic-plastic singular stress becomes larger with the increasing of the linear hardening coefficient. When the linear hardening coefficient decreases to a certain value, the effective stress in most of the yield zone equals approximately the yield stress. The stress distribution in the elastic region under small-scale yielding condition was also investigated.

ConGrap -Contour Detection Based on Gradient Map of Images

In this paper, the authors present ConGrap, a novel contour detector for finding closed contours with semantic connections. Based on gradient-based edge detection, a Gradient Map is generated to store the orientation of every edge pixel. Using the edge image and the generated Gradient Map, ConGrap separates the image into semantic parts and objects. Each edge pixel is mapped to a contour by a three-stage hierarchical analysis of neighbored pixels and ensures the closing of contours. A final post-process of ConGrap extracts the contour borderlines and merges them, if they semantically relate to each other. In contrast to common edge and contour detections, ConGrap not only produces an edge image, but also provides additional information （e.g., the borderline pixel coordinates the bounding box, etc.） for every contour. Additionally, the resulting contour image provides closed contours without discontinuities and merged regions with semantic connections. Consequently, the ConGrap contour image can be seen as an enhanced edge image as well as a kind of segmentation and object recognition.

Exploration in Optimal Design of an Airfoil with a Leading Edge Rotating Cylinder

Based on the theory of moving surface boundary layer control(MSBC),a concept of an airfoil having a rotating cylinder at the leading edge has been developed and experimentally proven to have good aerodynamic performance even at large angles of attack.Thus,this research aims to give guidance on optimizing the design of this kind of airfoil with high lift coefficients.Using computational fluid dynamics(CFD)technique,the CFD simulation results have been compared with the experimental results available in the literature,and then the SST two-equation model is selected as the appropriate turbulence model.At a given cylinder surface velocity ratio,the cylinder diameter d,the drop height of trailing edgeδand the curvatures of the pressure and suction surfaces of the airfoil are regarded as the optimal design parameters and the airfoil lift coefficient is considered as the optimization objective function.Therefore,using orthogonal optimization method,we herein develop a new design of airfoil favorable for having a rotating leading edge.It has been numerically proven that the resulting airfoil has good capability of achieving a substantially superior performance when compared to the airfoils of the prior art.

Dielectric properties of Pb (Zn_(1/3) Nb_(2/3)) O_3-PbZrO_3-PbTiO_3 solid solution near morphotropic phase boundary

The dielectric properties of Pb(Zn1/3Nb2/3)O3-PbZrO3-PbTiO3 (PZN-PZ-PT) system near the rhombohedral/tetragonal morphotropic phase boundary (MPB) are carefully studied in this paper.It is found that,for all samples,the curves around the temperatures of dielectric permittivity peak show the characteristics of diffuse phase transition.The change in PbZrO3/PbTiO3 ratio has much influence on the dielectric properties of the samples.The extent of diffuse phase transition increases with the increasing Zr/Ti ratio.The samples in rhombohedral region have typical diffuse phase transition in the temperature range measured.However,for the samples with tetragonal symmetry,a spontaneous normal ferroelectric-relaxor phase transition exists at temperature lower than that of permittivity peak.This normal ferroelectric-relaxor phase transition is confirmed by the experiment of thermally driven current.The analysis of TEM reveals that the samples in tetragonal region show a 90° macrodomain structure,while the samples in rhombohedral region have the configuration of microdomain structure.

Investigation on Expanded Boundary Layer Equation

In this paper, the two approximate hypotheses in boundary layer theory p/y=0,2u/x2=0, are reinvestigated and analyzed, while a new approximate hypothesis, p/y =μ2v/y2, is suggested to establish a new expanded boundary layer equation. Its formula of equilibrium of force coincides basically with that of Navier-Stokes equations on the boundary while the applicable range of the boundary layer expansion equation can be extended to the leading edge region. Theoretical analysis and discussion are presented.

Measurement of thermal boundary conductance between metal and dielectric materials using femtosecond laser transient thermoreflectance technique

The thermal boundary conductance of Al/SiO2, Al/Si, Au/SiO2, and Au/Si are measured by a femtosecond laser transient thermoreflectance technique. The distinct differences of the interfacial thermal conductance between these samples are observed. For the same metal film, the thermal boundary conductance between metal and substrate decreases with the thermal conductivity of the substrate. The measured results are explained with the phonon diffusion mismatch model by introducing a phonon transmission coefficient across the interface.

Prediction and control of trailing edge noise based on bionic airfoil

As a promising means,the passive porosity technology is used for the trailing-edge noise reduction of a bionic airfoil.The detailed two-dimensional Large Eddy Simulation is achieved to gain a better understanding of the prediction and passive control of trailing-edge noise source with the non-porous and porous treatment,respectively.The flow fields around the bionic airfoil indicate that the leading-edge separation causes both the noise contributors,i.e.,the turbulent boundary layer and the vortex shedding.In addition,the effect of the porous trailing edge is substantiated in the distribution of the static pressure.The relevant noise also suggests a pronounced noise reduction potential in excess of 10 dB,but it has dependence on the flow resistivities.The two trailing-edge noise reduction mechanisms are characterized:(1)the suppression of the tonal vortex shedding noise;(2)the reduction of broadband turbulent boundary layer scattering noise.The findings may be used as reference in the design of silent aircraft.

Sedimentary features of the Permian-Triassic boundary sequence of the Meishan section in Changxing County,Zhejiang Province

The Global Stratotype Section and Point(GSSP) for the Permian-Triassic boundary was placed in Bed 27 of Meishan section D where the conodont species Hindeodus parvus first occurs.Bed 27 was usually considered comprising continuouslydeposited,homogeneous silty limestone,with no depositional hiatus near the boundary.Detailed study on the boundary sequence revealed that a typical firmground characterized by Glossifungites ichnofacies developed about 2 cm below the Permian-Triassic boundary in Bed 27.Fossil content and lithology show apparent differences across the firmground crust.The abundance of the Permian bioclasts decreases significantly across the firmground,and is accompanied by a shift of dominating carbonate precipitation from calcite to dolomite.The firmground marked a rapid transgression at the very end of the Late Permian and significant shifts of sedimentary environment and paleoclimate.This transgressive submerging surface is also observed at the Huangzhishan section of the shallow-water carbonate platform facies in Zhejiang Province,the Jiangya section of the lower-slope to basinal-margin facies in Hunan Province,the Pingdingshan section of the basinal facies in Anhui Province of South China,as well as the Selong section in Tibet of the northern peri-Gondwana.The transgressive submerging surface marks the onset of a rapid global transgression at the latest Permian.