An object-oriented hierarchical case representation of automotive panels in a computer-aided process planning system

Case-based reasoning (CBR) has a promising application prospect in computer-aided process planning (CAPP) for automotive panels. How to effectively represent and organize the abundant information in the cases has a crucial impact on the effectiveness of case retrieval and adaptation. This paper presents an object-oriented hierarchical case representation scheme for automotive panels in process planning. The scheme is based on an extended object model and case object model which are extensions of the object model in object-oriented modelling technology. Information in cases is divided into three kinds and each kind is represented by different kinds of classes. Accordingly the representation scheme has four layers and different kinds of classes have different functionalities. A car fender case is presented as an example.     

Correlative mechanism of hydraulic-mechanical property in cemented paste backfill

Hydraulic characteristic is a good indication of binder hydration, which determines the strength development of cemented paste backfill (CPB). Therefore, the hydraulic characteristic should be communicated with the mechanical property to provide an advanced knowledge that can help mine workers make a rational strategy and reduce the mining cycle. An experimental program was performed to obtain the hydraulic (monitored by suction and volumetric water content) and mechanical properties (unconfined compressive strength (UCS) test) of CPB at the 28 days curing age. According to the monitoring and testing results, the relationships between the hydration reaction rate and volumetric water content (VWC), suction and VWC, suction and UCS were established. The hydration degree showed a liner rise as the VWC decreased. Curves of the VWC and UCS were featured with a nonlinear reduction and nonlinear growth (both are exponential functions) as the suction rising, respectively. These established relationships validated the strong correlative mechanism of hydraulic and mechanics behavior for CPB. Also, the results of the present research indicated that the hydraulic characteristics and mechanical property were strongly coupled. These correlations and couplings will be of great importance to understand the hardening process of CPB and bring to a safe CPB field operation.     

塔尔油对铝酸钠溶液种分附聚过程的强化作用研究

附聚是铝酸钠溶液中氢氧化铝颗粒最主要的长大方式,强烈影响产品强度,是影响氧化铝品质最重要的过程之一。本文以铝土矿浮选药剂中常用的捕收剂塔尔油作为添加剂,研究了其对过饱和铝酸钠溶液种分速率、附聚效率的影响,结果表明,浓度小于0.1g/L的塔尔油对过饱和铝酸钠溶液种分速率影响很小,但能强烈促进附聚过程,在添加量为0.1g/L的条件下,附聚效率由2.68上升到3.64。研究结果对于铝土矿浮选捕收剂选择及过饱和铝酸钠溶液的种分附聚添加剂的选择具有指导意义。     

Constitutive Modeling of Dynamic Recrystallization Behavior and Processing Map of 38MnVS6 Non-Quenched Steel

The dynamic recrystallization behavior of 38MnVS6 non-quenched steel was investigated by hot compression tests on a Gleeble1500 thermomechanical simulator. True stress-strain curves and deformed specimens were obtained in the temperature range of 850-1200 °C and the strain rate range of 0.01-10 s^?1. By regression analysis of the experimental results, the critical strain model and austenite grain size model for dynamic recrystallization were established as a function of Zener-Hollomon parameter. The dynamic recrystallization kinetic model for 38MnVS6 non-quenched steel was established on the basis of the modified Avrami equation. In addition, based on the dynamic material model, the processing map of the steel was established at the strain of 0.5. It was found that the unstable phenomena of the steel did not appear at the deformation conditions. The processing map exhibited a domain of complete dynamic recrystallization occurring in the temperature range of 950-1200 °C and the strain rate range of 0.01-5 s^?1, which were the optimum parameters for the hot working of the steel.     

Mg-Y共掺杂高电压钴酸锂正极材料的合成及其性能研究

将Co3O4、Li2CO3、Mg(OH)2 和Y2O3 按一定化学计量比称取并混合均匀后,采用高温固相法合成LiCo1-x-yMgxYyO2正极材料并探究了Mg-Y 共掺杂对钴酸锂高电压性能的影响.采用X 射线衍射(XRD)和扫描电镜(SEM)分别表征其晶体结构和形貌.LiCo1-x-yMgxYyO2正极材料高电压性能...     

INFLUENCE OF Ge ON THE ANTIFERROMAGNETIC TRANSITION AND γ → ε MARTENSITIC TRANSFORMATION OF Fe-24Mn ALLOYS

The aims of the work were to study the effect of Ge (0-6wt. %) on the paramagnetic-antiferromagnetic transition and martensitic transformation of Fe-Mn alloy using the susceptibility, micro structure examination, X-ray diffraction (XRD) and latticeparameter measurement. Ge lowers the Néel temperature, TN, and enhances the magnetic susceptibility x, changing the Pauli paramagnetism above TN to paramagnetismstate obeying the Curie Weiss law, which is essentially similar to that of γ-Fe-Mnalloys containing Al or Si; Ge depresses γ-ε martensitic transformation, whichattribute to Ge increasing the stacking fault energy; Moreover, Ge increases the lattice parameter of γ phase, and low content Ge increases the lattice parameter of γphase more than that of high Ge content. Comparing Ge(4s24p2) with Si(3s23p2) and Al(3s2 3p1), which have the same outer-shell of electron structures, we found that their effects on the martensitic transformation of Fe-Mn alloy are completely different. The result suggests the     

呋喃自硬树脂砂应用"A+B"固化剂

呋喃自硬树脂砂的固化,在生产过程中通常采用一种固化剂,总酸度不变,用改变加入量调整砂块固化程度来达到起模.而A B是两种不同总酸度的固化剂,通过改变两种固化剂的各自用量,达到总量不变,而总酸度改变,使砂块的固化和强度得到稳定.     

旋压力的测试方法及试验研究

旋压力是选择旋压成形设备的依据,也是影响旋压件成形质量的重要工艺参数之一。本文综述了旋压力试验研究的发展历程,阐述了旋压力电测方法的工作原理、应用现状及技术特点,并提出了几种测量旋压力的新的方法和手段。     

34工位IC引线框架级进模设计

介绍了IC引线框架级进冲模的特点并着重讲述了其排样设计中的整形工位和模具结构中的卸料、微调和安全机构，可供精密级进冲模设计参考。