具有离散阻尼器的结构动力分析

本文论述了几种结合离散阻尼器于结构以增大其阻尼的方法。假设原结构是无阻尼的,用复数表示加在它的某些离散点上的阻尼器的刚度,推导出了一个对无阻尼结构的刚度阵作局部修改的运动方程,指出了用模态应变能法解决这个问题时的缺点,提出了用改进的直接频率响应积分法与模态综合法求解它。

断裂力学的发生和发展

<正> 一、断裂力学的由来 断裂力学是近二十年来发展起来的一门新兴学科。它研究的对象是材料或结构中的缺陷或者说,裂纹。它要解决的问题是:为了

Numerical study of bifurcation solutions of spherical Taylor-Couette flow

The steady bifurcation flows in a spherical gap (gap ratio sigma=0.18) with rotating inner and stationary outer spheres are simulated numerically for Re(c1)less than or equal to Re less than or equal to 1 500 by solving steady axisymmetric incompressible Navier-Stokes equations using a finite difference method. The simulation shows that there exist two steady stable flows with 1 or 2 vortices per hemisphere for 775 less than or equal to Re less than or equal to 1 220 and three steady stable flows with 0, 1, or 2 vortices for 1 220

A stochastic jump and deterministic dynamics model of impact failure evolution with rate effect

Motivated by the observation of the rate effect on material failure, a model of nonlinear and nonlocal evolution is developed, that includes both stochastic and dynamic effects. In phase space a transitional region prevails, which distinguishes the failure behavior from a globally stable one to that of catastrophic. Several probability functions are found to characterize the distinctive features of evolution due to different degrees of nucleation, growth and coalescence rates. The results may provide a better understanding of material failure.

Evolution induced catastrophe

Fracture due to coalescence of microcracks seems to be catalogued in a new model of evolution induced catastrophe (EIC). The key underlying mechanism of the EIC is its automatically enlarging interaction of microcracks. This leads to an explosively evolving catastrophe. Most importantly, the EIC presents a fractal dimension spectrum which appears to be dependent on the interaction.

多煤层开采时岩层垮落过程的数值模拟

运用自行开发的岩层破断过程分析 (SFPA2D)系统模拟了多煤层开采时岩层的垮落过程。数值模拟结果表明 ,虽然上部煤柱的存在改变了上覆岩层结构 ,但岩层的垮落仍具有明显的周期性 ,地表的水平移动和垂直下沉仍具有明显的对称性 ;当垮落带高度达到上部煤柱后 ,可能出现大面积的垮落 ,产生较大的次生来压现象 ,从而影响下部长壁工作面的安全。通过和相似材料模拟以及理论分析结果的对比 ,本次数值模拟基本上反映了多煤层开采时采动岩体的动态发展过程 ,SFPA2D系统可以作为模拟采动覆岩破坏过程的一种新方法

光学蛋白质芯片检测乳腺癌胸苷磷酸化酶的初步研究

目的应用我国自行研制的无标记光学蛋白质芯片检测乳腺癌组织中的胸苷磷酸化酶(Thymidine phosphorylase,TP),为建立一种快速、简便的临床检测方法进行初步探索。方法将 TP 的多克隆抗体固定于已经过表面改性的固相光学抛光硅片表面上制备无标记光学蛋白质芯片,通过椭偏光学显微成像技术检测20例经病理证实的乳腺浸润性导管癌组织标本和正常组织标本中 TP 水平,以芯片灰度值表示组织中 TP 浓度高低。同时应用 ELISA 方法测定,并比较两种方法检测结果的一致性。结果 20例癌组织的灰度值35.40±11.55,20例正常组织的灰度值为26.80±8.78,两组间差异具显著性意义(P<0.05)。以44.36(正常组织平均值+2倍标准差)为阈值,乳腺癌检测的灵敏度为20.00%,特异度为100.00%。同 ELISA 检测结果相比,在20例乳腺癌组织标本检测中,两种方法的一致性具极显著意义(P<0.01)。结论我国首创的椭偏光学显微成像技术简单、直观,结合光学蛋白质芯片可用于胸苷磷酸化酶的临床检测。

光学蛋白质芯片检测乳腺癌组织中胸苷磷酸化酶的临床初探

目的应用我国自行研制的光学蛋白质芯片检测乳腺癌组织中的胸苷磷酸化酶 (Thymidinephosphorylase,TP) ,为建立一种快速、简便的临床检测方法进行初步探索。方法应用TP的多克隆抗体制备光学蛋白质芯片 ,通过椭偏光学显微成像技术检测20例经病理证实的乳腺浸润性导管癌组织标本和正常组织标本中的TP水平 ,以灰度值表示组织中TP浓度高低。同时应用ELISA方法测定 ,并比较两种方法检测结果的一致性。结果20例癌组织的灰度值35.40±11.55,20例正常组织的灰度值为26.80±8.78,两组间差异具显著性意义 (P<0.05)。以44.36(正常组织平均值 +2倍标准差 )为阈值 ,乳腺癌检测的灵敏度为20.00 %,特异度为100.00 %。同ELISA检测结果相比 ,在20例乳腺癌组织标本检测中 ,两种方法的一致性具极显著意义(P<0.01)。结论我国首创的椭偏光学显微成像技术简单、直观 ,结合光学蛋白质芯片可用于胸苷磷酸化酶的临床检测

郭永怀先生诞辰九十周年纪念文集

目录

燃烧物理学基础

Euler Solution Using Adaptive Cartesian Grid With A Gridless Boundary Treatment

A quadtree-based adaptive Cartesian grid generator and flow solver were developed. The grid adaptation based on pressure or density gradient was performed and a gridless method based on the least-square fashion was used to treat the wall surface boundary condition, which is generally difficult to be handled for the common Cartesian grid. First, to validate the technique of grid adaptation, the benchmarks over a forward-facing step and double Mach reflection were computed. Second, the flows over the NACA 0012 airfoil and a two-element airfoil were calculated to validate the developed gridless method. The computational results indicate the developed method is reasonable for complex flows.

A Simple Model For Predicting The Void Fraction Of Gas/Non-Newtonian Fluid Intermittent Flows In Upward Inclined Pipes

In this work, a simple correlation, which incorporates the mixture velocity, drift velocity, and the correction factor of Farooqi and Richardson, was proposed to predict the void fraction of gas/non-Newtonian intermittent flow in upward inclined pipes. The correlation was based on 352 data points covering a wide range of flow rates for different CMC solutions at diverse angles. A good agreement was obtained between the predicted and experimental results. These results substantiated the general validity of the model presented for gas/non-Newtonian two-phase intermittent flows.

Energetic protons emitted from coulomb explosion dynamics of large-sized hydrogen clusters driven by an ultrashort intense laser pulse

Protons with very high kinetic energy of about 10keV and the saturation effect of proton energy for laser intensity have been observed in the interaction of an ultrashort intense laser pulse with large-sized hydrogen clusters. Including the cluster-size distribution as well as the laser-intensity distribution on the focus spot, the theoretical calculations based on a simplified Coulomb explosion model have been compared with our experimental measurements, which are in good agreement with each other.

Modified formula of Malus' law for Glan-Taylor polarizing prisms

A simple three-axis model has been developed, which has been successfully applied to the analysis of the light transmittance in spatial incident angle and the simulation of modified formula of Malus' law for Glan-Taylor prisms. Our results indicate that the fluctuations on the cosine squared curve are due to specific misalignments between the axis of the optical system, the optical axis of the prism and the mechanical axis (rotation axis) of prism, which results in the fact that different initial relative location of the to-be-measured-prism in the testing system corresponds to different shape of Malus' law curve. Methods to get absolutely smooth curve are proposed. This analysis is available for other kinds of Glan-type prisms. (C) 2004 Elsevier B.V. All rights reserved.

Infrared luminescence properties of bismuth-doped barium silicate glasses

Infrared (IR) luminescence covering 1.1 to similar to 1.6 mu m wavelength region was observed from bismuth-doped barium silicate glasses, excited by a laser diode at 808 nm wavelength region, at room temperature. The peak of the IR luminescence appears at 1325 nm. A full width half-maximum (FWHM) and the lifetime of the fluorescence is more than 200 nm and 400 mu s, respectively. The fluorescence intensity increases with Al2O3 content, but decreases with BaO content. We suggest that the IR luminescence should be ascribed to the low valence state of bismuth Bi2+ or Bi+, and Al3+ ions play an indirect dispersing role for the infrared luminescent centers.