A hot compression bonding process was developed to prepare a novel laminated composite consisting of high-Cr cast iron （HCCI） as the inner layer and low carbon steel （LCS） as the outer layers on a Gleeble 3500 the...A hot compression bonding process was developed to prepare a novel laminated composite consisting of high-Cr cast iron （HCCI） as the inner layer and low carbon steel （LCS） as the outer layers on a Gleeble 3500 ther- momechanicat simulator at a temperature of 950 ℃ and a strain rate of 0. 001 s 1. Interfacial bond quality and hot deformation behaviour of the laminate were studied by mierostructural characterisation and mechanical tests. Experi- mental results show that the metallurgical bond between the constituent metals was achieved under the proposed bonding conditions without discernible defects and the formation of interlayer or intermetallic layer along the inter- face. The interfacial bond quality is excellent since no deterioration occurred around the interface which was deformed by Vickers indentation and compression test at room temperature with parallel loading to the interface. After well cladding by the LCS, the brittle HCCI can be severely deformed （about 57 % of reduction） at high temperature with crack-free. This significant improvement should be attributed to the decrease of crack sensitivity due to stress relief by soft claddings and enhanced flow property of the HCCI by simultaneous deformation with the LCS.展开更多
为克服采用真实设备进行全球海上遇险与安全系统(Global Maritime Distress and Safety System,GMDSS)培训容易产生误报警、干扰正常通信及成本昂贵的缺点,需要研发基于局域网的GMDSS仿真设备,如窄带直接印字电报(Narrow Band Direct Pr...为克服采用真实设备进行全球海上遇险与安全系统(Global Maritime Distress and Safety System,GMDSS)培训容易产生误报警、干扰正常通信及成本昂贵的缺点,需要研发基于局域网的GMDSS仿真设备,如窄带直接印字电报(Narrow Band Direct Printing Telegraph,NBDP),Inmarsat-C船站,Inmarsat-B船站等。在分析NBDP系统组成、工作原理和通信流程的基础上,研究并给出了NBDP系统的仿真模型。考虑了信道条件对通信效果的影响,搭建了基于局域网的NBDP仿真系统平台。采用VC++6.0为开发工具,研制了NBDP仿真系统。通过教学实践验证,该仿真系统具有仿真度高、界面友好、系统稳定等优点。展开更多
To measure the working band of a digital attenuator automatically,a program based on virtual instrument was carried out,using Agilent E8362B network analyzer as its measuring tool.In the program,the attenuation values...To measure the working band of a digital attenuator automatically,a program based on virtual instrument was carried out,using Agilent E8362B network analyzer as its measuring tool.In the program,the attenuation values can be automatically written into Excel table to form the frequency-attenuation curve.Finally,through analyzing the attenuation in different frequency,the best working band of the digital attenuator can be determined easily,and the whole process is automated.Compared with the traditional way of changing the measured parameters manually and recording the measured data one by one,the developed method in the paper can avoid the cumbersome manual operation and its possible errors to improve the measurement accuracy and efficiency.展开更多
基金Item Sponsored by National Natural Science Foundation of China(51474127)
文摘A hot compression bonding process was developed to prepare a novel laminated composite consisting of high-Cr cast iron （HCCI） as the inner layer and low carbon steel （LCS） as the outer layers on a Gleeble 3500 ther- momechanicat simulator at a temperature of 950 ℃ and a strain rate of 0. 001 s 1. Interfacial bond quality and hot deformation behaviour of the laminate were studied by mierostructural characterisation and mechanical tests. Experi- mental results show that the metallurgical bond between the constituent metals was achieved under the proposed bonding conditions without discernible defects and the formation of interlayer or intermetallic layer along the inter- face. The interfacial bond quality is excellent since no deterioration occurred around the interface which was deformed by Vickers indentation and compression test at room temperature with parallel loading to the interface. After well cladding by the LCS, the brittle HCCI can be severely deformed （about 57 % of reduction） at high temperature with crack-free. This significant improvement should be attributed to the decrease of crack sensitivity due to stress relief by soft claddings and enhanced flow property of the HCCI by simultaneous deformation with the LCS.
文摘为克服采用真实设备进行全球海上遇险与安全系统(Global Maritime Distress and Safety System,GMDSS)培训容易产生误报警、干扰正常通信及成本昂贵的缺点,需要研发基于局域网的GMDSS仿真设备,如窄带直接印字电报(Narrow Band Direct Printing Telegraph,NBDP),Inmarsat-C船站,Inmarsat-B船站等。在分析NBDP系统组成、工作原理和通信流程的基础上,研究并给出了NBDP系统的仿真模型。考虑了信道条件对通信效果的影响,搭建了基于局域网的NBDP仿真系统平台。采用VC++6.0为开发工具,研制了NBDP仿真系统。通过教学实践验证,该仿真系统具有仿真度高、界面友好、系统稳定等优点。
基金Fujian Province Key Technology Projects Fund(No.2006H0092)
文摘To measure the working band of a digital attenuator automatically,a program based on virtual instrument was carried out,using Agilent E8362B network analyzer as its measuring tool.In the program,the attenuation values can be automatically written into Excel table to form the frequency-attenuation curve.Finally,through analyzing the attenuation in different frequency,the best working band of the digital attenuator can be determined easily,and the whole process is automated.Compared with the traditional way of changing the measured parameters manually and recording the measured data one by one,the developed method in the paper can avoid the cumbersome manual operation and its possible errors to improve the measurement accuracy and efficiency.
