An optimun search algorithm for the coherent acquisition in direct-sequence spread-spectrum （DSSS） receivers is proposed and analyzed in this paper. The system consists of two major parts： a phase region estimator ...An optimun search algorithm for the coherent acquisition in direct-sequence spread-spectrum （DSSS） receivers is proposed and analyzed in this paper. The system consists of two major parts： a phase region estimator and a phase alignment detector. We use an auxiliary sequence to correlate the incoming signal in the phase region estimator. Since the cross-correlation value between the auxiliary sequence and the incoming PN signal has linear magnitude, and can provide the direction for the phase updating, an optimum search algorithm, try and error method, can be adopted to obtain the phase region information of the incoming signal. The mean acquisition time is derived through the signal flow graph theory. The time is compared with that of the conventional serial search scheme, and the results show that the proposed scheme can achieve coarse acquisition significantly faster than the conventional scheme.展开更多
Using atom force microscopy (AFM), in vitro transcription, PAGE and other experimental technologies, it is observed that, in active genes of mice (Balb/c) nuclear DNA fragments of non-transcriptional state, only regul...Using atom force microscopy (AFM), in vitro transcription, PAGE and other experimental technologies, it is observed that, in active genes of mice (Balb/c) nuclear DNA fragments of non-transcriptional state, only regulation sequences at both ends are associated with scaffold proteins (indissociable proteins) and some transcriptional factors such as complexes (dissociable proteins) made of gene-coding proteins and specific auxiliary small molecules, while there are no combining proteins in intermediate coding sequences. However, in active genes of transcriptional state, both regulation sequences and intermediate coding sequences are associated with active transcriptional factors by non-covalent bonds.This paper shows the prospective application of AFM observation and in vitro transcription in the research on gene expression and regulation. It also offers some theoretical basis for localization of specific genes in human genomes.展开更多
文摘An optimun search algorithm for the coherent acquisition in direct-sequence spread-spectrum （DSSS） receivers is proposed and analyzed in this paper. The system consists of two major parts： a phase region estimator and a phase alignment detector. We use an auxiliary sequence to correlate the incoming signal in the phase region estimator. Since the cross-correlation value between the auxiliary sequence and the incoming PN signal has linear magnitude, and can provide the direction for the phase updating, an optimum search algorithm, try and error method, can be adopted to obtain the phase region information of the incoming signal. The mean acquisition time is derived through the signal flow graph theory. The time is compared with that of the conventional serial search scheme, and the results show that the proposed scheme can achieve coarse acquisition significantly faster than the conventional scheme.
文摘Using atom force microscopy (AFM), in vitro transcription, PAGE and other experimental technologies, it is observed that, in active genes of mice (Balb/c) nuclear DNA fragments of non-transcriptional state, only regulation sequences at both ends are associated with scaffold proteins (indissociable proteins) and some transcriptional factors such as complexes (dissociable proteins) made of gene-coding proteins and specific auxiliary small molecules, while there are no combining proteins in intermediate coding sequences. However, in active genes of transcriptional state, both regulation sequences and intermediate coding sequences are associated with active transcriptional factors by non-covalent bonds.This paper shows the prospective application of AFM observation and in vitro transcription in the research on gene expression and regulation. It also offers some theoretical basis for localization of specific genes in human genomes.
