高精度机器视觉对准测量系统设计

设计了用于半导体先进封装光刻设备中的高精度机器视觉对准测量系统,明确了机器视觉对准测量系统工作原理、设计指标及系统设计中需要考虑的关键技术点,同时给出了机器视觉对准测量系统关键零部件的设计,并给出了对准测量系统最终在整机上测得的性能数据。测试结果表明,所设计的机器视觉对准测量系统完全可以满足集成电路先进封装工艺需求。     

包装热处理

本文简述了包装热处理的实施方法、适用范围及注意事项。以5CrNiMo、GCr15钢零件为例,包装热处理能减少工件表面氧化和脱碳的缺陷,是一种简便、低成本的工艺。     

Ant colony optimization for the two-dimensional loading vehicle routing problem

In this paper a combination of the two most important problems in distribution logistics is considered, known as the two-dimensional loading vehicle routing problem. This problem combines the loading of the freight into the vehicles, and the successive routing of the vehicles along the road network, with the aim of satisfying the demands of the customers.     

Microstructure models for cellular materials

Laguerre tessellations generated by random sphere packings are promising models for the microstructure of cellular or polycrystalline materials. In this paper, the case of hard sphere packings with lognormal or gamma distributed volumes is investigated. The dependence of the geometric characteristics of the Laguerre cells on the volume fraction of the sphere packing and the coefficient of variation of the volume distribution is studied in detail. The moments of certain cell characteristics are described by polynomials, which allows to fit tessellation models to real materials without further simulations. The procedure is demonstrated by the examples of open polymer and aluminium foams.     

Container loading with multi-drop constraints

In this paper, an algorithm for the container-loading problem (CLP) with multi-drop constraints is presented. When adding multi-drop constraints, we demand that the relevant boxes must be available, without rearranging others, when each drop-off point is reached. To make the solutions feasible in the real world, it is further demanded that all boxes are placed in a feasible manner with respect to load-bearing strength and with proper support from below. This makes it possible to load consignments originating from builder merchants. A heuristic based on a tree search framework is proposed. It uses greedy solutions to evaluate each choice taken. To make the framework more generic, a dynamic breadth is proposed. Based on problem characteristics and the time limit imposed, it will choose the breadth of the tree, making sure that the time is utilised most profitably. The algorithm is tested on new real-world data from a Danish company distributing construction products. For the solutions to these problems to be feasible in a real-world setting, both multi-drop and load-bearing strength constraints are essential. The obtained results show that the proposed model and algorithm are able to solve the new real-world problems in fractions of a second. Furthermore, results obtained on benchmark problems indicate that the algorithm performs comparably with other more specialised methods.     

高效规整填料塔技术在苯酐精制过程中的应用

介绍了国内苯酐精制新工艺和高效规整填料塔技术。实际应用结果表明新工艺比旧有技术和设备提高了产品质量和收率 ,处理能力也大幅提高 ,能耗明显下降。     

A genetic algorithm for the two-dimensional knapsack problem with rectangular pieces

Given a set of rectangular pieces and a rectangular container, the two-dimensional knapsack problem (2D-KP) consists of orthogonally packing a subset of the pieces within the container such that the sum of the values of the packed pieces is maximized. If the value of a piece is given by its area, the objective is to maximize the covered area of the container. A genetic algorithm (GA) is proposed addressing the guillotine case of the 2D-KP as well as the non-guillotine case. Moreover, an orientation constraint may optionally be taken into account and the given piece set may be constrained or unconstrained. The GA is subjected to an extensive test using well-known benchmark instances. Compared with recently published methods, the GA yields competitive results.     

气体辅助注射保压过程的数值分析

基于气体辅助注射成型保压过程的工程认识，利用粘性，可压缩非牛顿流体基本方程，得到了气体辅助注射保压过程分析的控制方法，并采用有限元法／有限差分法实现了对保压过程的数值模拟，并对过实例说明了气体辅助注射的优越性。     

Three-dimensional Computational Fluid Dynamics Modeling of Two-phase Flow in a Structured Packing Column

Characterizing the complex two-phase hydrodynamics in structured packed columns requires a power-ful modeling tool. The traditional two-dimensional model exhibits limitations when one attempts to model...     

Catalytic packed bed non‐thermal plasma reactor for the extraction of hydrogen from hydrogen sulfide

The decomposition of hydrogen sulfide (H₂S) to hydrogen and sulfur with Al₂O₃, MoO_x/Al₂O₃, CoO_x/Al₂O₃ and NiO/Al₂O₃ packed non‐thermal plasma dielectric barrier discharge reactor was studied. The reaction was carried out with 5‐mm discharge gap during the decomposition of 5 vol.% H₂S at 150 ml/min (STP) flow rate. Typical results indicated the conversion of ~50% at a specific input energy of ~0.92 kJ/l H₂S and 10% (in length) packed reactor showed the best conversion. Among the catalysts studied, MoO_x and CoO_x supported on Al₂O₃ showed high performance, which may be caused by synergy between plasma excitation of the carrier gas molecules and catalytic behaviour of MoO_x and CoO_x. Copyright © 2012 John Wiley & Sons, Ltd.