三通塑件注射模设计

以一个具有细小的三通小孔并同时具有内、外螺纹的塑件为例,介绍了模具的结构设计,并就二向碰穿的关键性技术问题提出了工艺解决方法,另外,设计还使用了Moldflow软件对塑件进行了注射成型流动分析,为模具设计提供了一定的理论依据。     

Cluster computing: the commodity supercomputer

The availability of high‐speed networks and increasingly powerful commodity microprocessors is making the usage of clusters, or networks, of computers an appealing vehicle for cost effective parallel computing. Clusters, built using Commodity‐Off‐The‐Shelf (COTS) hardware components as well as free, or commonly used, software, are playing a major role in redefining the concept of supercomputing. In this paper we discuss the reasons why COTS‐based clusters are becoming popular environments for running supercomputing applications. We describe the current enabling technologies and present four state‐of‐the‐art cluster‐based projects. Finally, we summarise our findings and draw a number of conclusions relating to the usefulness and likely future of cluster computing. Copyright © 1999 John Wiley & Sons, Ltd.     

The SUPRENUM preprototype: Status and experiences

A SUPRENUM preprototype with 9 processors communicating via a clusterbus is running. The prototype and preprototype background is explained and the article describes the current hardware and software environment, the developed and applied analyses, profiling and display tools. An introduction to and some results of parallel information retrieval algorithms, running on SUPRENUM, are given. The article closes with an overview of the running applications and some ideas for the following preprototyping steps.     

Date movement and control substrate for parallel adaptive applications

In this paper, we present the Data Movement and Control Substrate (DMCS), a library which implements low‐latency one‐sided communication primitives for use in parallel adaptive and irregular applications. DMCS is built on top of low‐level, vendor‐specific communication subsystems such as LAPI (Low‐level Application Programme Interface) for IBM SP machines, as well as on widely available message‐passing libraries like MPI for clusters of workstations and PCs. DMCS adds a small overhead to the communication operations provided by the lower communication system. In return, DMCS provides a flexible and easy to understand application program interface for one‐sided communication operations. Furthermore, DMCS is designed so that it can be easily ported and maintained by non‐experts. Copyright © 2002 John Wiley & Sons, Ltd.     

福建省武夷山江墩铅锌矿区推覆构造地质特征

江墩铅锌矿化区出露地层较简单,有三叠系焦坑组灰白色中粒石英砂岩和震旦系云母片岩以及第四系.野外地质勘查及已有地质资料分析,区内发育一条走向北西-南东,倾向北东的推覆断裂及一条走向北东-南西,倾向北西的张性正断层,控制区内两次岩浆活动,其一是花岗质岩浆活动,其二是闪长质岩浆活动,两次岩浆活动致使推覆构造分段出现.从大量地质勘查资料论证,江墩矿化区推覆断裂的存在,并简要分析了推覆断裂的地质构造特征以及岩浆活动和控矿作用,在区域构造分析及岩浆活动岩性分析基础上,结合同类型矿床的地质构造特征、分布规律、组合特征等进行类比,论证其铅、锌矿床及含矿母岩岩体矿化点均与推覆断裂有成因、空间上的联系,是地质找矿的一个重要因素.     

Parallel computation on multilayer cluster grids

Cluster architectures are increasingly used to solve high‐performance computing applications. To build more computational power, sets of clusters, interconnected by high‐speed networks, can be used in an elaboration to form a cluster grid. In this type of architecture, it is difficult to exploit all the internal resources of a cluster, because each one can be shielded by a firewall and is usually configured with machines where there is only one visible IP front‐end node that hides all its internal nodes from the external world. The exploitation of resources is even more complicated if we consider the general case where each internal node of a cluster can be a front‐end node of an another cluster. This type of architecture has been defined as a multilayer cluster grid. In this paper, a Parallel Virtual Machine (PVM) extension is presented which, through a middleware solution based on the H2O distributed metacomputing framework, permits the building of a parallel virtual machine in a multilayer cluster grid environment. In addition, the existing code written for PVM can be executed into this environment without modifications. Copyright © 2007 John Wiley & Sons, Ltd.