空分精馏塔是空气分离设备的核心组成部分。随着我国空气分离设备行业的高速发展,传统项目式设计在设计效率与生产周期之间的矛盾日益突出。为提高设计效率,本文以精馏塔中常见的粗氩塔设计为例,通过采用参数化、模块化设计方法,进行Sol...空分精馏塔是空气分离设备的核心组成部分。随着我国空气分离设备行业的高速发展,传统项目式设计在设计效率与生产周期之间的矛盾日益突出。为提高设计效率,本文以精馏塔中常见的粗氩塔设计为例,通过采用参数化、模块化设计方法,进行Solid Edge三维模型快速设计以及基于Visual Studio C#的Solid Edge二次开发,实现了粗氩塔快速形体重构与工程图纸的智能输出,可极大地简化设计流程,提高设计效率,实现了设计资源有效整合与重复利用,具有一定的现实推广意义。展开更多
CAD technique and its software products have been d ev eloped independently of CAPP, but the market’s requirements on reducing lead-t ime of a new product and promoting automation of design and manufacture processe s...CAD technique and its software products have been d ev eloped independently of CAPP, but the market’s requirements on reducing lead-t ime of a new product and promoting automation of design and manufacture processe s need integration of CAPP with CAD. The base of CAXs’ integration in product d esign and manufacture is information integration. There are several information integration approaches, for example, by data format transition through special d ata interface, or by standard format file for data exchange (e.g. based on S TEP),etc, but the integrating approach based on PDM is a more advanced and effic ient one. The approach is based on a common database. The feature model data of a product created by the CAD sub-system is stored in the common database, and the CAPP or CAM sub-system can get access to the data for its own work, by whic h repeated input of the data is avoided and data redundancy is eliminated. T he integration approach of CAPP with CAD discussed in this paper is based on the approach. Solid Edge, one of the CAD software products of UGS company is a 3-D modeling software based on parametric feature modeling technique, which is easy to learn and use, so suitable for small and medium manufacturers’ application. The feature data of the part model created by Solid Edge Part includes geometri c and topologic information of the part which provides basic data needed by CAPP , but like other 3-D feature-based modeling software, no precision and materia l information which is also essential for CAPP. In this paper, an approach is pr esented by which the precision features and material features of the part are ad ded into the 3-D CAD part model of geometric feature. So-called precision features include dimension tolerance, shape tolerance and position tolerance and so-called material features include material type and hardness. All these data are expressed by a set of characters which, combined with the surface t ype name of the related geometric feature, is substituted for the original syste m name of the geometric feature by using the rename function of the feature tree in the EdgeBar of "Solid Edge Part" GUI. If a feature joint of the feature tree is pointed by the mouse cursor, the related profile of the model in the working area of Solid Edge Part GUI is highlighted. In this visual way, precision featu res and material features of the part are added into the part model and for each geometric feature of a part model, the surface type and dimensions created by t he 3-D feature-based modeling software are combined with the precision and mat erial properties added. Then by a VB program, all these feature data are extract ed from the model and stored in a feature table of the common database ready for CAPP visit. The database is built by using Microsoft Access. The precision feat ures and material features data are obtained by applying "split" function of VB to the character set extracted as the name property of each geometric feature ob ject of the part model. The VB program can be made a custom-defined menu comman d running in the GUI of Solid Edge Part. All of the other related key techniques are detailed in the paper and an example is given.展开更多
A theoretical study on the red-shift of laser-induced electro-absorption is presented. It is found that laser-induced red-shift scales with the cube root of the pump laser intensity in the optical tunneling regime and...A theoretical study on the red-shift of laser-induced electro-absorption is presented. It is found that laser-induced red-shift scales with the cube root of the pump laser intensity in the optical tunneling regime and has an obvious deviation from this scale in the multi-photon regime. Our results show that in the optical tunneling regime, the laser-induced red shift has the same law as that in the direct current （DC） approximation. Though the scales are the same in the optical tunneling regime, the physical pictures in the two cases are quite different. The electro-absorption in the DC case is a tunneling-assisted transition process, while the laser-induced electro-absorption is a mixed multi-photon process.展开更多
The transient acoustic field radiated by a piezoelectric thickness-mode transducer into a solid medium is theoretically analysed. It is proved that the field consists of the direct wave, the longitudinal edge waves, t...The transient acoustic field radiated by a piezoelectric thickness-mode transducer into a solid medium is theoretically analysed. It is proved that the field consists of the direct wave, the longitudinal edge waves, the shear edge.waves, the head wave and the surface waves. The wavefront approximations of all these waves are given which result in a clear physical picture which is not only simple but also cotains the main features of the field. The theoretical result well describes the experiment.展开更多
文摘空分精馏塔是空气分离设备的核心组成部分。随着我国空气分离设备行业的高速发展,传统项目式设计在设计效率与生产周期之间的矛盾日益突出。为提高设计效率,本文以精馏塔中常见的粗氩塔设计为例,通过采用参数化、模块化设计方法,进行Solid Edge三维模型快速设计以及基于Visual Studio C#的Solid Edge二次开发,实现了粗氩塔快速形体重构与工程图纸的智能输出,可极大地简化设计流程,提高设计效率,实现了设计资源有效整合与重复利用,具有一定的现实推广意义。
文摘CAD technique and its software products have been d ev eloped independently of CAPP, but the market’s requirements on reducing lead-t ime of a new product and promoting automation of design and manufacture processe s need integration of CAPP with CAD. The base of CAXs’ integration in product d esign and manufacture is information integration. There are several information integration approaches, for example, by data format transition through special d ata interface, or by standard format file for data exchange (e.g. based on S TEP),etc, but the integrating approach based on PDM is a more advanced and effic ient one. The approach is based on a common database. The feature model data of a product created by the CAD sub-system is stored in the common database, and the CAPP or CAM sub-system can get access to the data for its own work, by whic h repeated input of the data is avoided and data redundancy is eliminated. T he integration approach of CAPP with CAD discussed in this paper is based on the approach. Solid Edge, one of the CAD software products of UGS company is a 3-D modeling software based on parametric feature modeling technique, which is easy to learn and use, so suitable for small and medium manufacturers’ application. The feature data of the part model created by Solid Edge Part includes geometri c and topologic information of the part which provides basic data needed by CAPP , but like other 3-D feature-based modeling software, no precision and materia l information which is also essential for CAPP. In this paper, an approach is pr esented by which the precision features and material features of the part are ad ded into the 3-D CAD part model of geometric feature. So-called precision features include dimension tolerance, shape tolerance and position tolerance and so-called material features include material type and hardness. All these data are expressed by a set of characters which, combined with the surface t ype name of the related geometric feature, is substituted for the original syste m name of the geometric feature by using the rename function of the feature tree in the EdgeBar of "Solid Edge Part" GUI. If a feature joint of the feature tree is pointed by the mouse cursor, the related profile of the model in the working area of Solid Edge Part GUI is highlighted. In this visual way, precision featu res and material features of the part are added into the part model and for each geometric feature of a part model, the surface type and dimensions created by t he 3-D feature-based modeling software are combined with the precision and mat erial properties added. Then by a VB program, all these feature data are extract ed from the model and stored in a feature table of the common database ready for CAPP visit. The database is built by using Microsoft Access. The precision feat ures and material features data are obtained by applying "split" function of VB to the character set extracted as the name property of each geometric feature ob ject of the part model. The VB program can be made a custom-defined menu comman d running in the GUI of Solid Edge Part. All of the other related key techniques are detailed in the paper and an example is given.
基金Project supported by the Fundamental Research Funds for the Central Universities,China (Grant No.A735496)the National Natural Science Foundation of China (Grant No.61178018)the Ph.D. Funding Support Program of the Education Ministry of China (Grant No.20110185110007)
文摘A theoretical study on the red-shift of laser-induced electro-absorption is presented. It is found that laser-induced red-shift scales with the cube root of the pump laser intensity in the optical tunneling regime and has an obvious deviation from this scale in the multi-photon regime. Our results show that in the optical tunneling regime, the laser-induced red shift has the same law as that in the direct current （DC） approximation. Though the scales are the same in the optical tunneling regime, the physical pictures in the two cases are quite different. The electro-absorption in the DC case is a tunneling-assisted transition process, while the laser-induced electro-absorption is a mixed multi-photon process.
文摘The transient acoustic field radiated by a piezoelectric thickness-mode transducer into a solid medium is theoretically analysed. It is proved that the field consists of the direct wave, the longitudinal edge waves, the shear edge.waves, the head wave and the surface waves. The wavefront approximations of all these waves are given which result in a clear physical picture which is not only simple but also cotains the main features of the field. The theoretical result well describes the experiment.
