1Ax1 high molecular weight glutenin subunit （HMW-GS） gene expression cassette （GEC） lacking vector backbone sequences together with selectable marker Bar GEC were co-transformed into Chinese hexaploid cultivars Ee...1Ax1 high molecular weight glutenin subunit （HMW-GS） gene expression cassette （GEC） lacking vector backbone sequences together with selectable marker Bar GEC were co-transformed into Chinese hexaploid cultivars Een 1 and Emai 12 to test the feasibility and the efficiency of explant regeneration, transformation frequency and transgene expression comparing with whole vector transformation by the approaches of plasmid extraction and excision, immature embryo isolation, particle co-bombardment, tissue culture, DNA extraction, PCR amplification, southern hybridization, leaf-painting test and SDS-PAGE etc. No significant difference was shown in tissue culture response of the proportion of embryogenic calli, somatic embryogenesis and regeneration frequency between GEC and whole plasmid bombarded embryos, but both regenerated less well than non-bombarded control. Total 56 plantlets that survived PPT selection had insertion of at least the Bar gene, 18 were from the GEC treatment and 38 from the whole plasmid treatment, the escape ratio averaged 0.23. Six independent transplants f230 - f235 with GEC transformation from genotype Emai 12 presented clear PCR amplification bands of Bar and 1Ax1 gene. The transformation and co-transformation frequency were 3.51 and 100% respectively. PCR amplification using a primer-pair specific for ampicillin resistant gene indicated the existence of Amp^R gene in whole vectors but the removal in GECs and transplants. Southern blot of total DNA and PCR products from transgenic plants of 1Ax1 GEC confirmed the integration of the transgene 1Ax1 and the absence of the EcoR Ⅰ recognition site at both ends of the 1Ax1 GEC when integrated. SDS-PAGE showed the expression of 1Ax1 GEC and un-expression of whole plasmid. The length of integrated fragment, the proportion of the gene of interest （GOI） and the selectable marker （MG）, bombardment pressure and genotypes are vital for the expression of a transformed GEC.展开更多
振荡器的频率稳定度在时域一般用阿伦方差表征,在频域一般用相位噪声谱密度函数表征,两者存在一定的数学转换关系,即可以由频域测量的相位噪声谱密度函数转换为时域的阿伦方差.t<0.1 ms时短期频率稳定度的时域测量非常困难.利用两者...振荡器的频率稳定度在时域一般用阿伦方差表征,在频域一般用相位噪声谱密度函数表征,两者存在一定的数学转换关系,即可以由频域测量的相位噪声谱密度函数转换为时域的阿伦方差.t<0.1 ms时短期频率稳定度的时域测量非常困难.利用两者之间的转换关系对振荡器的时域稳定度进行了间接测量,并用实测数据进行了验证.
Abstract：
Frequency stability of oscillator commonly can be denoted by Allan variance in time domain, and by phase noise power spectrum density function in frequency domain. There is a definite transform relation of mathematics, it is to say that Allan variance of time domain can be obtained by transforming phase noise power spectrum density function, especially it is more applicable when τ < 0. 1 ms because it is very difficult to measure short - term frequency stability in time domain. The transformation relation between the two denotations of short-term frequency is used to measure Allan variance indirectly and validated by measured data.展开更多
基金supported by China Post-Doctorial Foundation(2002031255)Rothamsted International Foundation(2002)of the UKNatural Science Foundation of Zhejiang Province,China(M303081).
文摘1Ax1 high molecular weight glutenin subunit （HMW-GS） gene expression cassette （GEC） lacking vector backbone sequences together with selectable marker Bar GEC were co-transformed into Chinese hexaploid cultivars Een 1 and Emai 12 to test the feasibility and the efficiency of explant regeneration, transformation frequency and transgene expression comparing with whole vector transformation by the approaches of plasmid extraction and excision, immature embryo isolation, particle co-bombardment, tissue culture, DNA extraction, PCR amplification, southern hybridization, leaf-painting test and SDS-PAGE etc. No significant difference was shown in tissue culture response of the proportion of embryogenic calli, somatic embryogenesis and regeneration frequency between GEC and whole plasmid bombarded embryos, but both regenerated less well than non-bombarded control. Total 56 plantlets that survived PPT selection had insertion of at least the Bar gene, 18 were from the GEC treatment and 38 from the whole plasmid treatment, the escape ratio averaged 0.23. Six independent transplants f230 - f235 with GEC transformation from genotype Emai 12 presented clear PCR amplification bands of Bar and 1Ax1 gene. The transformation and co-transformation frequency were 3.51 and 100% respectively. PCR amplification using a primer-pair specific for ampicillin resistant gene indicated the existence of Amp^R gene in whole vectors but the removal in GECs and transplants. Southern blot of total DNA and PCR products from transgenic plants of 1Ax1 GEC confirmed the integration of the transgene 1Ax1 and the absence of the EcoR Ⅰ recognition site at both ends of the 1Ax1 GEC when integrated. SDS-PAGE showed the expression of 1Ax1 GEC and un-expression of whole plasmid. The length of integrated fragment, the proportion of the gene of interest （GOI） and the selectable marker （MG）, bombardment pressure and genotypes are vital for the expression of a transformed GEC.
文摘振荡器的频率稳定度在时域一般用阿伦方差表征,在频域一般用相位噪声谱密度函数表征,两者存在一定的数学转换关系,即可以由频域测量的相位噪声谱密度函数转换为时域的阿伦方差.t<0.1 ms时短期频率稳定度的时域测量非常困难.利用两者之间的转换关系对振荡器的时域稳定度进行了间接测量,并用实测数据进行了验证.
Abstract：
Frequency stability of oscillator commonly can be denoted by Allan variance in time domain, and by phase noise power spectrum density function in frequency domain. There is a definite transform relation of mathematics, it is to say that Allan variance of time domain can be obtained by transforming phase noise power spectrum density function, especially it is more applicable when τ < 0. 1 ms because it is very difficult to measure short - term frequency stability in time domain. The transformation relation between the two denotations of short-term frequency is used to measure Allan variance indirectly and validated by measured data.
