A DUAL-SURFACE DAMAGE MODEL AND EVALUATION FOR NATURAL SOILS WITHIN THE THERMOMECHANICAL FRAMEWORK

Naturally deposited or residual soils exhibit more complicated behavior than remolded clays. A dual-surface damage model for structured soils is developed based on the thermodynamics framework established in our first paper. The shift stresses and the transformation between the generalized dissipative stress space and actual stress space are established following a systematic procedure. The corresponding constitutive behavior of the proposed model is determined, which reflects the internal structural configuration and damage behavior for geomaterials. Four evolution variables κj^i（i=D, R;j=V, S） and the basic parameters λ, s, v and e0 are introduced to account for the progressive loss of internal structure for natural clays. A series of fully triaxial tests and isotropic compression tests are performed for structured and reconstituted samples of Beijing and Zhengzhou natural clays. The validation of the proposed model is examined by comparing the numerical results with the experimental data.     

Diagnostic system for two dimension intensity distribution of laser beam

The diagnostic system for two dimension(2-D)intensity distribution of laserbeam is a measuring instrument for many parameters of laser beam.2-D intensity distributionplot of laser beam is obtained by the two dimension scanning mirror which is controlled by amicrocomputer to scan the laser beam on a detector.Many parameters of laser beam such asthe isointensity distribution plot,the beam diameter,the beam waist diameter,the laser pow-er,the diverge angle and the beam brightness,are given by means of the microcomputer pro-cessing the data measured.Theoretical analysis of beam parameter transform is given.     

关于Ismail—May算子线性组合的一至逼近

设T_n(f;x)表示如下的Ismail—May算子     

关于一类S1，13（△（2）mn）插值与逼近

设△^（2）_mn是矩形域Ｄ＝［ａ，ｂ］(?)［ｃ，ｄ］的Ⅱ－型三角剖分．S^1，1₃（△^（2）_mn）是带边界条件的二元三次样条空间：本文我们将讨论一类S^1，1₃（△^（2）_mn）的插值问题，证明了它的存在性，唯一性及逼近阶：如果ｆ∈Ｃ^４（Ｄ），则有｜ｆ－ｓ｜≤ｋ（ｌ）·ｍａ     

红外光纤与PbS红外探测器耦合研究

本文以红外光纤与PbS红外探测器相耦合,构成“带尾钎”的新型组合件。基于光纤波导可绕曲性使红外探测器在红外系统中的位置有更多的随意性和灵活性,并能有效减小杂散光的干扰,改善系统的信噪比。     

多元Szász—Mirkjan算子的一致逼近

本文研究了多元Szása—Mirakjan算子在C_2B(T)中的逼近性质,利用K—泛函,建立了等价的逼近定理.主要结果如下 定理设f∈C_2B(T),0a) ;(ii)‖S_n,m(f)-f‖_∞ =0(n^-a);(iii)a)‖f(x+tφ(x),y)-2f(x,y)+f(x-tφ(x),y)‖_∞ =0(t<     

Structure and coordination behavior of 2,3-bis(2-furanyl)quinoxaline

The title compound crystallizes in the orthorhombic system, space group Pna2₁, with a = 15.721 (5) Å, b = 16.945 (5) Å, c = 4.6961 (15) Å, V = 1251.0 (7) ų, and Z = 4. One furanyl ring is rotated with respect to the quinoxaline group by 66.4(2)°, and another furanyl ring almost lies coplanar with the quinoxaline moiety. Although it has potential for chelation involving the furanyl oxygen atom and the nearest nitrogen atom of the quinoxaline group, poor coordination behavior was observed while attempting to synthesize its complexes with a metal center like Ru(II), Cu(II), or Co(III), entirely different from its analogue 2,3-bis(2-pyridyl)quinoxaline. This is most likely due to the weak donating ability of the furanyl oxygen atom and the steric hindrance.     

半参数回归模型的渐近有效L-估计

对半参数回归模型yi=χiTβ+g(χi)+ei,i=1,2,…,n,对非参数函数g(·)采用核估计的方法,构造了参数向量β的L-估计量λn,在一些正则条件下,获得了λn的渐近正态性和非参数函数g(·)的估计量gn(t)的最优收敛速度可达到O(n-(1/3)),并且给出了标准化L估计量λn的渐近分布的Berry-Esseen界.