增压膨胀和全精馏无氢制氩技术在1000m~3/h空分设备上的应用

介绍采用增压膨胀和全精馏无氢制氩技术的1000m3/h空分设备的流程设计和技术指标,简述了安装调试中遇到的问题以及解决方法。     

Q235B中板延伸率低的原因分析

针对延伸率低的Q235B中板，通过对拉伸试样的化学成分、断口、非金属夹杂物和金相组织等理化检验，分析了造成试样层状断口、中板延伸率低的原因，并提出了一些对策。     

A simple method for the evaluation of fracture toughness of a multi-layered laminate based on the failure stress of sub-laminates

A simple analytical method is presented that can be used to predict the intralaminar fracture toughness of multilayered composite laminate based on the failure stresses of its sub laminates. MCCI approach is followed to verify the fracture toughness of a base laminate and the method is validated comparing the available test data on the toughness value of the base laminate with the prediction. It is observed that a better representation of carbon —epoxy base laminate by its sub laminate gives very good agreement in prediction within 3%.     

Iterative ultrasonic signal and image deconvolution for estimation of the complex medium response

The ill‐conditioned inverse problem of estimating ultrasonic medium responses by deconvolution of RF signals is investigated. The primary difference between the proposed method and others is that the medium response function is assumed to be complex‐valued rather than restricted to being real‐valued. Derived from the complex medium model, complex Wiener filtering is presented, and a Hilbert transform related limitation to inverse filtering type methods is discussed. We introduce a nonparametric iterative algorithm, the least squares method with point count regularization (LSPC). The algorithm is successfully applied to simulated and experimental data and demonstrates the capability of recovering both the real and imaginary parts of the medium response. The simulation results indicate that the LSPC method can outperform Wiener filters and improve the resolution of the ultrasound system by factors as high as 3.7. Experimental results using a single element transducer and a conventional medical ultrasound system with a linear array transducer show that despite the errors in pulse estimation and the noise in the RF signals, excellent results can be obtained, demonstrating the stability and robustness of the algorithm. © 2006 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 266–277, 2005     

Mixed finite element method for coupled thermo‐hydro‐mechanical process in poro‐elasto‐plastic media at large strains

A mixed finite element for coupled thermo‐hydro‐mechanical (THM) analysis in unsaturated porous media is proposed. Displacements, strains, the net stresses for the solid phase; pressures, pressure gradients, Darcy velocities for pore water and pore air phases; temperature, temperature gradients, the total heat flux are interpolated as independent variables. The weak form of the governing equations of coupled THM problems in porous media within the element is given on the basis of the Hu–Washizu three‐filed variational principle. The proposed mixed finite element formulation is derived. The non‐linear version of the element formulation is further derived with particular consideration of the THM constitutive model for unsaturated porous media based on the CAP model. The return mapping algorithm for the integration of the rate constitutive equation, the consistent elasto‐plastic tangent modulus matrix and the element tangent stiffness matrix are developed. For geometrical non‐linearity, the co‐rotational formulation approach is utilized. Numerical results demonstrate the capability and the performance of the proposed element in modelling progressive failure characterized by strain localization and the softening behaviours caused by thermal and chemical effects. Copyright © 2005 John Wiley & Sons, Ltd.     

缓倾斜薄-中厚矿体高效开采技术应用研究

为了满足辽宁金凤黄金矿业有限责任公司杨树金矿扩建后500t／d生产能力的需要，针对缓倾斜薄一中厚矿体进行了高效开采技术的综合试验研究。文中重点介绍了采矿方法优化研究、控制爆破技术和锚杆加固顶板围岩技术等在该矿的试验应用情况。     

二氧化硅薄膜材料热传导尺寸效应的实验研究

对微米SiO2薄膜材料沿膜面方向热传导尺寸效应进行了实验研究。结果表明,膜厚从微米数量级的尺寸开始,其传热的热导率就已开始体现出鲜明的膜厚尺寸依赖特性(即sizeeffect),经由微观能量输运理论分析后,得到了实验与理论相吻合的结果。     

重介质密度调节自适应神经元控制器

文章针对选煤厂重介质密度的自动调节系统设计了一种自适应神经元控制器。仿真比较显示 :神经元控制器的参数通过自适应不断调整 ,可以达到比PID更好的控制效果。     

对多孔介质物体孔隙度-蜡封法改进的探讨--以土壤团聚体为例

融资难问题已成为中国中小企业发展的桎梏。当前 ,在中国资本市场欠发达的金融体系下 ,间接融资无疑是中小企业最佳的融资途径。然而 ,长期以来 ,国有商业银行却忽视了对中小企业的信贷支持,要涉足这一领域,在“以市场为导向 ,以客户为中心,以效益为原则,以风险控制为主线”的信贷经营思想指导下,必须进行面向中小企业的信贷业务创新和组织结构调整     

中速磨煤机计算中若干问题的探讨(续)

目前工程设计中对ＭＰＳ、ＨＰ等中速磨煤机的计算基本上采用制造厂商提供的规范和方法，但在相同煤质条件下，按不同厂商计算方法所得结果可能出现明显的差异；另一方面，国内用以指导中速磨计算的一些规范也存在着不够明确之处，这些情况都给中速磨的选型、工程计算带来了困难。根据工程设计实践和对电厂试验资料的分析，对中速磨煤机出力计算、煤粉细度、出口风温和风工况等问题进行了讨论，提出了一些新的见解和建议