Creep-induced local lattice parameter changes in a monocrystalline nickel-base superalloy

The γ-γ lattice mismatch of specimens of the monocrystalline nickel-base superalloy SRR 99 has been measured by a high-resolution X-ray diffraction technique for the undeformed state and after high-tem-perature creep deformation. During creep deformation beyond the minimum creep rate (total strain =0.5%), the lattice mismatches, measured in and perpendicular to the [001] stress axis, respectively, un-dergo changes in opposite directions. This reflects the buildup of a complex deformation-induced triaxial state of internal stress in the phases y and γ. The overall resolved shear stresses that act in γ and y due to the combined action of the external and internal stresses are estimated, and the conditions under which cutting of the γ phase by dislocations should occur are discussed.     

内高压成形三台阶轴过程中内压值影响的有限元分析

以内高压成形台阶轴过程中压力参数的影响为研究目标,利用大变形非线性塑性有限元方法对成形零件的壁厚和应变分布规律进行了探索。给出了不同内压条件下零件的壁厚及应变分布,并就内压对成形的影响进行了讨论。分析了不同压力对起皱和减薄等缺陷的影响,并在此基础上给出了相应的实验结果。分析结果表明,内压值的选取对内高压成形台阶轴具有重要影响,对文中台阶轴来说,30MPa的压力值是成形的最佳压力。     

Evaporative light scattering mass detection for high-performance liquid chromatographic analysis of sucrose polyester blends in cooking oils

A high-performance liquid chromatographic method is described to determine the sucrose polyester (SPE) content in seven blends of cooking oils. Four gel-permeation chromatography (GPC) columns were used in series with an evaporative light scattering mass detector to separate the SPE from the acylglycerols in the final chromatogram. The SPE fraction was collected off the GPC column and injected onto a reverse-phase C-18 column for quantitation with sucrose octaacetate as an internal standard and a gradient of nonaqueous solvents as mobile phase. The chromatograms were interference-free, with only two sharp peaks appearing. The standards were linear from 500 to 5000 μg/mL with a correlation coefficient of r=0.999. The mean percent recovery (n=9) and standard deviation were 102±6.7. The detector could detect amounts as low as 5 μg SPE.     

基于自由运动一维标定物的多摄像机参数标定方法与实验

一维标定方法易于实现且标定效率高,为了克服现有一维标定方法的一些不足,本文提出一种用一维标定物标定多摄像机内外参数的方法,首先进行两两标定,在此过程中,假定主点坐标近似已知而仅考虑畸变、焦距、旋转和平移等参数,接着利用基本矩阵及一维标定物上特征点之间的几何约束,估计两摄像机的内外参数,两两标定完成后,采用Dijkstra最短路径法和捆绑调整对多摄像机系统进行全局标定(含主点坐标),仿真和真实实验表明本文的方法是切实有效的.     

实验室用超高温氢气钼丝炉的研制

通过结构设计和负荷计算，研制出适合于实验室使用的以钼丝为电热体，电熔镁砂或镁铝尖晶石为沪芯材料，H2－N2混合气体为保护气氛和最高使用温度达1950℃的内挂式氢气钼丝炉。     

汽车工业生产用热熔胶膜的研制

介绍了汽车工业生产内装饰复合材料用热熔胶膜的性能及其研制状况。这种热熔胶膜具有使用便捷,高效,生产、使用过程中没有污染的具有热熔胶膜的特长。     

N－氰基乙亚胺酸乙酯含量的气相色谱分析

采用GC-900气相色谱仪、3%PEG-12000/Chromosorb880AWDMCS填充柱和FID检测器,以水杨酸甲酯为内标物测定N-氰基乙亚胺酸乙酯含量,回收率在98.5%—101.8%之间,标准偏差为0.27%,变异系数为0.27%。     

Coordination between strategic forest management and tactical logistic and production planning in the forestry supply chain

In this paper, we study the coordination mechanism in the forestry supply chain between strategic forest management and tactical production planning. We first formulate an integrated model to establish a theoretical benchmark for performance of the entire supply chain. It is a mixed integer programming model that involves harvesting, bucking, transportation, production, and sales decisions for both tactical and strategic planning levels. We then present two sequential approaches S‐A and S‐B where the coordination is done through internal pricing. S‐A is the approach currently used in practice where harvesting in the forest is the main driver of the supply chain activities and internal pricing is introduced to control bucking decision in a separate stage. In contrast, S‐B takes downstream demand information into consideration and internal pricing directly influences harvesting decision in the first stage. In order to find the appropriate setting of internal pricing that leads to the system optimum, we suggest two heuristics H‐I and H‐II. The internal pricing in H‐I is based on dual values and in H‐II, it is derived from a Lagrangian decomposition. A real‐life case study in the Chilean forestry industry is used to compare the results of different approaches. It is shown that the new sequential approach S‐B generates as good feasible solution as that obtained from the integrated approach but in much less time. Both heuristics H‐I and H‐II bring about near‐optimal feasible solutions. H‐II also provides optimistic bound of the optimal objective function value, which can be used as a measure of the solution quality.     

内构件存在时提升管内流动及颗粒混合行为研究

he hydrodynamics and solids mixing behavior in a riser with blunt internals are studied. A uniform radial distribution for solids fraction and particle velocity achieves near the internals. The turbulent velocity of particles near the wall increases with the addition of the internals, with the lateral solids mixing enhanced significantly. Probability density distribution of particle velocity is bimodal in the riser with internals, which is similar to that in the conventional riser, indicating that no significant difference in the micro flow structure exists between the riser with internals and the conventional riser. At the same time, the axial solids mixing behavior changes insignificantly with the addition of internals. These results indicate that the micro flow structure in the riser is very stable, which changes insignificantly with the change of the bed structure.     

ANSYS在整体式排水圆管分析中的应用

基于ANSYS APDL参数化设计语言编写程序,利用程序对整体式排水圆管进行数值计算.模型中考虑了不同荷载的施工方法,并利用路径映射技术实现了各截面的内力输出,从而合理地揭示了在土压力、外水压力和自重的共同作用下整体式排水圆管的位移、应力和内力分布规律.最后通过工程实例,验证了程序的可靠性.