为提升SRAM型FPGA电路块存储器和配置存储器抗单粒子翻转性能,本文提出一种脉冲屏蔽SRAM单元结构。该结构通过在标准的六管单元中加入延迟结构,增大单元对单粒子事件响应时间,实现对粒子入射产生的脉冲电流屏蔽作用。以64k SRAM作为验...为提升SRAM型FPGA电路块存储器和配置存储器抗单粒子翻转性能,本文提出一种脉冲屏蔽SRAM单元结构。该结构通过在标准的六管单元中加入延迟结构,增大单元对单粒子事件响应时间,实现对粒子入射产生的脉冲电流屏蔽作用。以64k SRAM作为验证电路进行单粒子翻转性能对比,电路的抗单粒子翻转阈值由采用标准六管单元的抗单粒子翻转阈值大于25 Me V·cm2·mg-1提升至大于45 Me V·cm2·mg-1,加固单元面积较标准六管单元增大约21.3%。30万门级抗辐照FPGA电路通过脉冲屏蔽单元结合抗辐照SOI工艺实现,其抗辐照指标分别为:抗单粒子翻转阈值大于37.3 Me V·cm2·mg-1,抗单粒子锁定阈值大于99.8 Me V·cm2·mg-1,抗电离总剂量能力大于200 krad(Si)。展开更多
We demonstrate a type of 2 × 2 multimode interference 3 dB coupler based on silicon-on-insulator.The fabrication tolerance was investigated by the effective index method and the guide mode method.The devices with...We demonstrate a type of 2 × 2 multimode interference 3 dB coupler based on silicon-on-insulator.The fabrication tolerance was investigated by the effective index method and the guide mode method.The devices with different lengths were fabricated and near-field output images were obtained.Tolerances to width,length and etch depth are 2,200 and 2μm,respectively.The devices show a uniform power distribution.展开更多
High boron iron-based alloy,a new kind of wear-resistant material was developed,and its microstructure and mechanical properties were studied. Moreover,the modification with V,Ti and RE-Mg was carried out as well. The...High boron iron-based alloy,a new kind of wear-resistant material was developed,and its microstructure and mechanical properties were studied. Moreover,the modification with V,Ti and RE-Mg was carried out as well. The results indicate that the high boron iron-based alloy comprises a dendritic matrix and interdendritic eutectic borides under as-cast condition. The matrix is made up of fine pearlite,and the eutectic boride has a crystal structure of M2B （M represents Fe,Cr or Mn）. The boride has a microhardness of HV 1 425 and is distributed in the form of continuous network,which is detrimental to the toughness of high boron iron-based alloy. Nevertheless,high boron iron-based alloy has a higher toughness than that of white cast iron,which is attributed to the matrix that is made up of lath-type martensite with high toughness. In order to increase the toughness further,V,Ti and RE-Mg were adopted to improve the morphology of boride. The results indicate that after modification the matrix grain is decreased in size by half,and the size of boride is also decreased,moreover,it is distributed more even though it is still continuous. After heat treatment,the boride network is break up and results in the further improvement of toughness of high boron iron-based alloy.展开更多
Photolysis of 4-acetyl-4-ethoxyformylcyclohexanone, 4-acetyl-4-phenylcyclohexanone and 1-acetyl-1-phenylcyclohexane in deuteriochloroform using a high pressure Hg-Xe lamp showed unusual polarizations. The results are ...Photolysis of 4-acetyl-4-ethoxyformylcyclohexanone, 4-acetyl-4-phenylcyclohexanone and 1-acetyl-1-phenylcyclohexane in deuteriochloroform using a high pressure Hg-Xe lamp showed unusual polarizations. The results are explained by the formation of a singlet exciplex of the ketone with deuteriochloroform and the photoaddition of deuteriochloroform to the ketone.展开更多
文摘为提升SRAM型FPGA电路块存储器和配置存储器抗单粒子翻转性能,本文提出一种脉冲屏蔽SRAM单元结构。该结构通过在标准的六管单元中加入延迟结构,增大单元对单粒子事件响应时间,实现对粒子入射产生的脉冲电流屏蔽作用。以64k SRAM作为验证电路进行单粒子翻转性能对比,电路的抗单粒子翻转阈值由采用标准六管单元的抗单粒子翻转阈值大于25 Me V·cm2·mg-1提升至大于45 Me V·cm2·mg-1,加固单元面积较标准六管单元增大约21.3%。30万门级抗辐照FPGA电路通过脉冲屏蔽单元结合抗辐照SOI工艺实现,其抗辐照指标分别为:抗单粒子翻转阈值大于37.3 Me V·cm2·mg-1,抗单粒子锁定阈值大于99.8 Me V·cm2·mg-1,抗电离总剂量能力大于200 krad(Si)。
基金Supported by the National Natural Science Foundation of China under Grant Nos.69896260 and 69990540。
文摘We demonstrate a type of 2 × 2 multimode interference 3 dB coupler based on silicon-on-insulator.The fabrication tolerance was investigated by the effective index method and the guide mode method.The devices with different lengths were fabricated and near-field output images were obtained.Tolerances to width,length and etch depth are 2,200 and 2μm,respectively.The devices show a uniform power distribution.
基金Sponsored by National Key Technologies Research and Development Program of China (2005BA324C)
文摘High boron iron-based alloy,a new kind of wear-resistant material was developed,and its microstructure and mechanical properties were studied. Moreover,the modification with V,Ti and RE-Mg was carried out as well. The results indicate that the high boron iron-based alloy comprises a dendritic matrix and interdendritic eutectic borides under as-cast condition. The matrix is made up of fine pearlite,and the eutectic boride has a crystal structure of M2B （M represents Fe,Cr or Mn）. The boride has a microhardness of HV 1 425 and is distributed in the form of continuous network,which is detrimental to the toughness of high boron iron-based alloy. Nevertheless,high boron iron-based alloy has a higher toughness than that of white cast iron,which is attributed to the matrix that is made up of lath-type martensite with high toughness. In order to increase the toughness further,V,Ti and RE-Mg were adopted to improve the morphology of boride. The results indicate that after modification the matrix grain is decreased in size by half,and the size of boride is also decreased,moreover,it is distributed more even though it is still continuous. After heat treatment,the boride network is break up and results in the further improvement of toughness of high boron iron-based alloy.
基金This work was supported by the National Natural Science Foundati on of China.
文摘Photolysis of 4-acetyl-4-ethoxyformylcyclohexanone, 4-acetyl-4-phenylcyclohexanone and 1-acetyl-1-phenylcyclohexane in deuteriochloroform using a high pressure Hg-Xe lamp showed unusual polarizations. The results are explained by the formation of a singlet exciplex of the ketone with deuteriochloroform and the photoaddition of deuteriochloroform to the ketone.
