Solution of scattering from rough surface with a 2D target above it by a hybrid method based on the reciprocity theorem and the forward-backward method

This paper proposes a hybrid method based on the forward-backward method （FBM） and the reciprocity theorem （RT） for evaluating the scattering field from dielectric rough surface with a 2D target above it. Here, the equivalent electric/magnetic current densities on the rough surface as well as the scattering field from it are numerically calculated by FBM, and the scattered field from the isolated target is obtained utilizing the method of moments （MOM）. Meanwhile, the rescattered coupling interactions between the target and the surface are evaluated employing the combination of FBM and RT. Our hybrid method is first validated by available MOM results. Then, the functional dependences of bistatic and monostatic scattering from the target above rough surface upon the target altitude, incident and scattering angles are numerically simulated and discussed. This study presents a numerical description for the scattering mechanism associated with rescattered coupling interactions between a target and an underlying randomly rough surface.

BOUNDARY ELEMENT METHOD FOR MOVING AND ROLLING CONTACT OF 2D ELASTIC BODIES WITH DEFECTS

A scheme of boundary element method for moving contact of two-dimensional elastic bodies using conforming discretization is presented. Both the displacement and the traction boundary conditions are satisfied on the contacting region in the sense of discretization. An algorithm to deal with the moving of the contact boundary on a larger possible contact region is presented. The algorithm is generalized to rolling contact problem as well. Some numerical examples of moving and rolling contact of 2D elastic bodies with or without friction, including the bodies with a hole-type defect, are given to show the effectiveness and the accuracy of the presented schemes.

Diagonal form fast multipole boundary element method for 2D acoustic problems based on Burton-Miller boundary integral equation formulation and its applications

This paper describes formulation and implementation of the fast multipole boundary element method （FMBEM） for 2D acoustic problems. The kernel function expansion theory is summarized, and four building blocks of the FMBEM are described in details. They are moment calculation, moment to moment translation, moment to local translation, and local to local translation. A data structure for the quad-tree construction is proposed which can facilitate implementation. An analytical moment expression is derived, which is more accurate, stable, and efficient than direct numerical computation. Numerical examples are presented to demonstrate the accuracy and efficiency of the FMBEM, and radiation of a 2D vibration rail mode is simulated using the FMBEM.

A Method for Preparation of Ordered Porous Silicon Based on a 2D SiO_2 Template

A new method for fabricating ordered porous silicon is reported. A two-dimensional silica nanosphere array is used as a template with a hydrofluoric acid-hydrogen peroxide solution for etching the nanospheres. The initial diameter and distribution of the holes in the resulting porous silicon layer are determined by the size and distribution of the silica nanospheres. The corrosion time can be used to control the depths of the holes. It is found that the presence of a SiO2 layer, formed by the oxidation of the rough internal surface of the hole, is the primary reason allowing the corrosion to proceed. Ultraviolet reflection and thermal conductivity measurements show that the diameter and distribution of the holes have a great influence on properties of the porous silicon.

NUMERICAL SIMULATION OF 2D FIBER-REINFORCED COMPOSITES USING BOUNDARY ELEMENT METHOD

The boundary dement method was improved for the 2D elastic composites with randomly distributed inclusions. This problem can be reduced to a boundary integral equation for a multi-connected domain. Further, considering the matrices of the tractions and displacements for each group of the identical inclusion were the same, an effective computational scheme was designed, since the orders of the resulting matrix equations can be greatly reduced. Numerical examples indicate that this boundary element method scheme is more effective than the conventional multi-domain boundary element method for such a problem. The present scheme can be used to investigate the effective mechanical properties of the fiber-reinforced composites.

Analysis of Cavitation Performance of a 2-D Hydrofoil Based on Mixed-iterative Method

以便学习一只 2-D 水翼船的成穴特征，联合非线性的成穴模型和混合重复的方法被用来预言并且分析水翼船的成穴表演。成穴元素非线性地基于格林公式和不安潜力面板方法被处理。同时，联合洞形状为的方法修理了重复和洞塑造的洞长度(CSCL ) 因为固定成穴数字(CSCN ) 重复被用来得出水翼船成穴的厚度和长度。通过计算结果的分析，成穴什么时候发生在水翼船上，能被结束压力和速度的 jump 潜在地在吸表面上在成穴结束区域和非成穴区域之间存在。在攻击的某些角度，成穴数字在成穴的长度上有否定影响。并且在攻击和成穴的一样的角度下面数，越大水翼船的厚度，越 shorter 成穴长度。

Fracture Mechanism of 3D, Five-directional Braided (SiO_2)_f /SiO_2 Composites Prepared by Silicasol-infiltration-sintering Method

Three-dimensional （3D） five-directional braided （SiO2）/SiO2 composites were prepared by silicasol-infiltration-sintering （SIS） method. The flexural properties and microstructures were studied. The flexural strength and flexural elastic modulus were found to be 73 MPa and 12 GPa, respectively. The results of stress vs deflection curve and SEM examinations revealed that the fracture mechanism of 3D, five-directional braided （SiO2）/SiO2 composite was a mixture mode of ductile and brittle. The ductile mode was attributed to the weak bonding strength of fiber/matrix at low temperature. The brittle fracture might be caused by the propagation of micro defect or crack, which existed in the as-prepared composites for the ten-cycle process.

杨树胞外蛋白的提取分离及2-D电泳体系的建立

该研究以美洲黑杨杂种优良无性系NL895杨（Populus deltoides×Populus euramericana cv.）组培苗叶片和茎段为研究对象,对NL895杨叶片细胞壁蛋白（cell wall proteins,CWPs）和茎段质外体蛋白（apoplastic proteins,APPs）的提取、分离和双向电泳等技术进行了系统研究。结果表明：10g以上叶片、超声波破碎10min、CaCl2法提取的细胞壁蛋白效果较好,经G-6-PDH酶活性检测,提取的细胞壁蛋白胞质污染率较低;真空渗透法提取的茎段质外体蛋白胞质污染率较前者高,但在允许范围之内。TCA/丙酮沉淀法纯化提取的细胞壁蛋白、pH 4-7的24cm胶条、上样量为500μg的双向电泳体系,其蛋白电泳图谱中的斑点多而清晰,斑点数达550多个,是叶片细胞壁蛋白电泳分析较适合的体系;pH 3-10胶条对茎段质外体蛋白的电泳分离效果较好。该研究初步建立了杨树胞外蛋白的提取、分离及2-DE电泳体系,为木本植物胞外蛋白的研究奠定了基础。

2维Schrdinger方程的高阶紧致ADI格式

利用4阶精度紧致格式离散1维Schrdinger方程的空间方向,并推广到2维Schrdinger方程问题.在时间方向用P-R ADI方法离散,经理论分析证明该格式具有高精度性、省时性和绝对稳定性,并证明该格式还保持离散的电荷守恒律以及能量守恒律,最后通过数值实验数据验证该格式的高效性和理论分析的正确性.

2-去氧-D-葡萄糖的离子色谱法分析

开发一种分析2-去氧-D-葡萄糖样品的离子色谱方法,该方法可准确定量2-去氧-D-葡萄糖样品的含量.经色谱分离条件优化,选用DIONEX CarboPac PA10（4 mm×250 mm）色谱柱,以18 mmol/L NaOH溶液为流动相,流速为0.8 mL/min,用脉冲安培检测器检测,实现2-去氧-D-葡萄糖、葡萄糖和氨基葡萄糖3种结构极为相似单糖的高效分离,建立起2-去氧-D-葡萄糖的离子色谱法.2-去氧-D-葡萄糖在0.618~61.8μg/mL范围内呈现良好的线性关系,相关系数为0.998 6,最低检测限为27.2μg/L,最低定量限为216.3μg/L,平均回收率101.3%,实验结果表明该离子色谱法检测2-去氧-D-葡萄糖,简单、灵敏,测定结果准确,是测定2-去氧-D-葡萄糖含量的有效方法.

关于2-D温度场计算的有限元法分析

目的 分析有限元法实现 2 -D温度场计算的一般规则及程序编制技巧 .方法 根据理论分析及实例 ,计算验证上述规则及技巧的正确性及在程序设计中的可行性 .结果 单元、单元节点的编号以及单元网格的形状对 2 -D温度场计算结果的精确度有很大的影响 ;而程序设计的技巧直接关系到计算能否顺利进行 .结论 遵循 2 -D有限元分析的一般原则加上适当的编程技巧 ,可顺利并精确地完成 2

基于改进的2D Otsu方法和YCgCr空间的肤色分割

为了弥补基于固定阈值的肤色分割方法存在的缺陷,在对多种彩色空间和肤色模型进行分析的基础上,提出采用改进的2-D Otsu方法和YC_gC_r彩色空间进行肤色分割。首先将光照补偿之后的肤色样本图像从RGB彩色空间转换到YC_gC_r彩色空间,并利用样本图像上的179221个肤色点建立2维高斯模型;进而将待分割的图像进行光照补偿并转换到YC_gC_r彩色空间,利用已经建立的高斯模型计算图像的肤色相似度,得到肤色相似度图像;最后,结合像素的空间邻域信息,使用改进的2-D Otsu方法对肤色相似度图像进行2值化处理。对这种方法进行了理论分析和实验验证。结果表明,该肤色分割算法有效地克服了使用固定阈值法进行图像分割时缺乏针对性和抗噪性的缺陷,该算法是可行的。

D-T_(2)二维核磁共振测井反演方法对比与适用性研究

D-T_(2)二维核磁共振测井技术能够直观地区分不同类型、不同赋存状态的孔隙流体,在油气勘探中应用广泛。目前,,国内外学者提出了很多二维核磁共振反演方法,但大多止步于数值模拟,需要研究不同反演方法针对不同采集序列的测井数据的适用性,优选反演方法,为二维核磁共振测井数据处理的软件模块开发提供参考。本文者,对此问题,基于二维核磁共振测井原理,详细研究了TSVD、BRD、LM-模平滑和TIST-L1正则化反演方法,分别对油水模型、气水模型数值模拟得到的CPMG和DE序列的回波信号,进行反演结果精度和计算效率的对比研究。通过数值模拟,对比分析了TSVD、BRD、LM-模平滑和TIST-L1正则化四种反演方法的反演结果和计算耗时,并优选反演方法对MR Scanner仪器SP模式测井数据处理。结果表明,对于油水和气水两种模型的CPMG和DE序列回波信号,TIST-L1正则化方法精度最高,LM-模平滑方法略差,但耗时较少,更适合测井数据处理,该方法针对A25井的处理结果与Geolog软件相符,能够满足数据处理的需要。

两种花吊丝竹叶片蛋白提取方法的2-DE比较

以2年生花吊丝竹的扦插苗为研究材料,对2种方法(TCA/酚提结合法和PEG法)提取的蛋白质的2-DE差异进行研究.结果表明:PEG法的5个组分的条带差异明显,全蛋白得到了有效分离,在F3中富集到了2条高丰度蛋白带;2种方法的2-DE图谱的均一性分析发现,PEG法中F3富集了高丰度蛋白,提高了2-DE中蛋白质的检测率和分辨率,PEG法中F1-F5共检测的蛋白总数超过了1700个,但是相邻组存在一定的重叠率,而TCA丙酮/酚提结合法只检测到约571个蛋白点,5个组与NF平均有439个蛋白点匹配,达到77.9%以上;质谱鉴定了5种差异蛋白,生物信息学分析发现这5种蛋白是糖酵解、糖异生和ATP合成的重要辅酶.2种方法的比较发现,PEG法能够将花吊丝竹叶片全蛋白中高丰度蛋白单一富集在16%的组分中,从而显著提高了2-DE的分辨率,再通过质谱技术能够检测到更多的影响生物体生长发育的低丰度蛋白,所以PEG法是一种切实可行的且较为理想的蛋白质提取方法.

BEM FOR SIMULATION OF A 2D ELASTIC BODY WITH RANDOMLY DISTRIBUTED CIRCULAR INCLUSIONS

Based on our 2D BEM software THBEM2 which can be applied to thesimulation of an elastic body with randomly distributed identicalcircular holes, a scheme of BEM for the simulation of elastic bodieswith randomly distributed circular inclusions is proposed. Thenumerical examples given show that the bound- ary element method ismore accurate and more effective than the finite element method forsuch a problem. The scheme presented van also be successfully used toestimate the effective elastic properties of composite Materials.

THE NAVIER-STOKES EQUATIONS IN STREAM LAYER AND ON STREAM SURFACE AND A DIMENSION SPLIT METHODS

In this paper,we proposal stream surface and stream layer.By using classical tensor calculus,we derive 3-D Navier-Stokes Equations(NSE)in the stream layer under semigeodesic coordinate system,Navier-Stokes equation on the stream surface and 2-D Navier-Stokes equations on a two dimensional manifold. After introducing stream function on the stream surface,a nonlinear initial-boundary value problem satisfies by stream function is obtained,existence and uniqueness of its solution are proven.Based this theory we proposal a new method called"dimension split method"to solve 3D NSE.

组织蛋白酶D、C-erbB-2、EGFR在大肠癌中的表达及临床意义

目的 :为研究 Cath- D、C- erb B- 2及 EGFR在大肠癌、腺瘤、炎症及正常粘膜中的表达情况及临床意义。方法 :采用免疫组化 ABC法对 80例大肠癌、44例大肠腺瘤、35例慢性结肠炎及 10例正常大肠粘膜进行上述三种指标的检测。结果 :80例大肠癌中上述三种指标的阳性率分别为 41%、39%及 41% ,三者共同阳性率为 16 .2 %。在 33例 Cath- D阳性标本中 C- erb B- 2阳性18例 (占 5 5 % ) ,在 Cath- D阴性标本中 C- erb B- 2阳性 13例 (2 8% ) ,二者间有显著性差异 (χ2 =5 .0 9,P<0 .0 5 )。33例 Cath- D阳性标本中 EGFR阳性 2 0例 (占 6 1% ) ,在 Cath- D阴性标本中 EGFR阳性 13例 (占 2 8% ) ,两者之比有显著差异 (χ2 =8.6 8,P<0 .0 5 )。有淋巴结转移者 Cath- D、C- erb B- 2及 EGFR阳性率明显高于无淋巴结转移者 (P<0 .0 1)。 3种指标的表达与患者年龄无关。大肠腺瘤伴轻、中、重度异型增生 EGFR阳性率分别为 2 5 %、70 %及 6 0 % ,轻度与中、重度异型增生间有显著性差异 (P<0 .0 5 )。结论 :有 Cath- D、C- erb B- 2及 EGFR表达的大肠癌易转移 ,EGFR对监视大肠腺瘤是否癌变有一定临床意义。

Reformatted method for two-dimensional detector arrays measurement data in proton pencil beam scanning

The spatial resolution of a commercial two-dimensional(2D)ionization chamber(IC)array is limited by the size of the individual detector and the center-to-center distance between sensors.For dose distributions with areas of steep dose gradients,inter-detector dose values are derived by the interpolation of nearby detector readings in the conventional mathematical interpolation of 2D IC array measurements.This may introduce significant errors,particularly in proton spot scanning radiotherapy.In this study,by combining logfile-based reconstructed dose values and detector measurements with the Laplacian pyramid image blending method,a novel method is proposed to obtain a reformatted dose distribution that provides an improved estimation of the delivered dose distribution with high spatial resolution.Meanwhile,the similarity between the measured original data and the downsampled logfilebased reconstructed dose is regarded as the confidence of the reformatted dose distribution.Furthermore,we quantify the performance benefits of this new approach by directly comparing the reformatted dose distributions with 2D IC array detector mathematically interpolated measurements and original low-resolution measurements.The result shows that this new method is better than the mathematical interpolation and achieves gamma pass rates similar to those of the original low-resolution measurements.The reformatted dose distributions generally yield a confidence exceeding 95%.

Eigenfunction expansion method and its application to two-dimensional elasticity problems based on stress formulation

This paper proposes an eigenfunction expansion method to solve twodimensional （2D） elasticity problems based on stress formulation. By introducing appropriate state functions, the fundamental system of partial differential equations of the above 2D problems is rewritten as an upper triangular differential system. For the associated operator matrix, the existence and the completeness of two normed orthogonal eigenfunction systems in some space are obtained, which belong to the two block operators arising in the operator matrix. Moreover, the general solution to the above 2D problem is given by the eigenfunction expansion method.

Efficient 2D Analysis of Interfacial Thermoelastic Stresses in Multiply Bonded Anisotropic Composites with Thin Adhesives

In engineering practice,analysis of interfacial thermal stresses in composites is a crucial task for assuring structural integrity when sever environmental temperature changes under operations.In this article,the directly transformed boundary integrals presented previously for treating generally anisotropic thermoelasticity in two-dimension are fully regularized by a semi-analytical approach for modeling thin multi-layers of anisotropic/isotropic composites,subjected to general thermal loads with boundary conditions prescribed.In this process,an additional difficulty,not reported in the literature,arises due to rapid fluctuation of an integrand in the directly transformed boundary integral equation.In conventional analysis,thin adhesives are usually neglected due to modeling difficulties.A major concern arises regarding the modeling error caused by such negligence of the thin adhesives.For investigating the effect of the thin adhesives considered,the regularized integral equation is applied for analyzing interfacial stresses in multiply bonded composites when thin adhesives are considered.Since all integrals are completely regularized,very accurate integration values can be still obtained no matter how the source point is close to the integration element.Comparisons are made for some examples when the thin adhesives are considered or neglected.Truly,this regularization task has laid sound fundamentals for the boundary element method to efficiently analyze the interfacial thermal stresses in 2D thin multiply bonded anisotropic composites.