Transmission probability method based on triangle meshes for solving the unstructured geometry neutron transport problem

The fuel assembly or core with unstructured geometry is frequently used in the advanced reactor. To calculate the fuel assembly, the transmission probability method (TPM) is widely used. However, the rectangular or hexagonal meshes are mainly used in the TPM codes for the normal core structure. The triangle meshes are most useful for expressing the complicated unstructured geometry. Even though the finite element method and Monte-Carlo method are well suited for solving the unstructured geometry problem, they are very time-consuming. Therefore, a TPM code based on the triangle meshes is developed here. This code was applied to the hybrid fuel geometry, and compared with the results of the MCNP code and other codes. The results of the comparison were consistent with each other. The TPM with triangle meshes can thus be applied to the two-dimensional arbitrary fuel assembly.     

任意载荷下三角形板单元的局部动力效应修正

推导了任意荷载激励下三角形板单元局部动力效应的修正公式,建立了三角形板单元局部效应的计算模型,从而为复杂边界结构的动力精确计算提供了一简便可行的方法。通过对一悬臂板进行结构动力时程分析及其局部动力效应修正,并与四边形板单元的局部效应计算结果比较发现:局部动力效应影响与加速度成正比,悬臂板在忽略局部效应的情况下,所得动内力与理论值及精确解相差较大,因此结构设计中必须考虑局部动力效应的影响。     

浅谈弧形建筑工程的测量放样

以莆田市体育中心田径场主体工程为例,介绍了弧形的建筑放样方法。     

Extended rotation‐free plate and beam elements with shear deformation effects

This paper describes a methodology for extending rotation‐free plate and beam elements to accounting for transverse shear deformation effects. The ingredients for the element formulation are a Hu–Washizu‐type mixed functional, a linear interpolation for the deflection and the shear angles over standard finite elements and a finite volume approach for computing the bending moments and the curvatures over a patch of elements. As a first application of the general procedure, we present an extension of the three‐noded rotation‐free basic plate triangle (BPT) originally developed for thin plate analysis to account for shear deformation effects of relevance for thick plates and composite‐laminated plates. The nodal deflection degrees of freedom (DOFs) of the original BPT element are enhanced with the two shear deformation angles. This allows to compute the bending and shear deformation energies leading to a simple triangular plate element with three DOFs per node (termed BPT+ element). For the thin plate case, the shear angles vanish and the element reproduces the good behaviour of the original thin BPT element. As a consequence the element is applicable to thick and thin plate situations without exhibiting shear locking effects. The numerical solution for the thick case can be found iteratively starting from the deflection values for the Kirchhoff theory using the original thin BPT element. A two‐noded rotation‐free beam element termed CCB+ applicable to slender and thick beams is derived as a particular case of the plate formulation. The examples presented show the robustness and accuracy of the BPT+ and the CCB+ elements for thick and thin plate and beam problems. Copyright © 2010 John Wiley & Sons, Ltd.     

提高多层砌体房屋抗震能力初探

针对多层砌体房屋在历次地震中损坏严重的现象，结合工程实践经验，提出抗震设防措施：利用地基与基础之间的褥垫层消减地震波；加强圈梁、构造柱的设置；适当增加含钢量；慎重对待鞭梢效应；有意设置避难空间：并将“三角形”的稳定性融入结构的抗震概念设计之中。     

打造长江文化旅游岛促进形成安徽文化旅游金三角

长江(含皖江)历史文化源远流长,应该成为旅游的重要内涵,但至今没有集中展示之地。其展示之地应是马鞍山江心洲。把江心洲打造成长江文化旅游岛(安徽不夜域、夜上海、夜巴黎),是因为她独具优越条件:一是区位特优,地处四大经济圈交汇处,旅游客源充足。二是特色独具,具有江水、细沙、大桥、景致等四绝。打造此岛的意义是优化安徽文化旅游产品结构、增添新的经济增长点,促进形成安徽文化旅游金三角(合肥——黄山——马鞍山)。建议市、省将此重大创意列入"十二五"规划,并批准设立长江文化旅游岛开发区(含采石、天门山)。     

Measuring Capillary Adhesive Forces in Fabrics

Capillarity of clothes constitutes an efficient way to help men and women evaporate their sweat, and so keep their comfort by lowering their wetness. The mechanism of water transport from skin onto fabric for its evaporation is physically studied. A Cahn balance is used to measure the dynamic of such an effect, and to confirm the proposed theory. The results point out several parameters of the structure of a fabric that govern sticking and the capillary properties.     

Soil particle size distribution and its relationship with soil water and salt under mulched drip irrigation in Xinjiang of China

Soil particle size distribution(PSD),one of the most important soil physical attributes,is of great importance to soil water movement,soil erosion and soil solute migration.In this study,the soil PSD of 563 soil samples from the mulched drip irrigated cotton fields in Xinjiang of China were measured by laser diffraction particle size analyzer.The soil PSD characteristics and its relations with soil water and salt were studied by using the combined methods of textural triangle,fractal and multifractal analys...     

Optimisation of the regional energy supply network: a multi-objective analysis in the province of Florence (Italy)

This work presents an integrated method for the optimisation of a regional wood-energy supply network. The model is based on a scalar system that comprises a demand point (district heating plants (DHP)) and bio-energy sources (supply basin (SB)), each of which is related to a biomass terminal. The objective of optimisation is based on both technical-logistics and environmental parameters. An SB is defined by the anisotropic weighted Voronoi tessellation methodology. The parameters are then aggregated to a multi-objective analysis that includes the optimisation of variables and compromise programming approach. Results permit the identification of the best supply chain organisation and the determination of the agro-forest energy districts where rural policy and intervention could be applied. The model was tested in the province of Florence (central Italy) to depict efficient scenarios for the fuelling of DHPs.