无碰撞区跳频/时序列理论界与设计

跳频(时)序列分析与设计是跳频(时)扩频通信系统的核心技术.无碰撞区跳频序列是近年新出现的一个研究方向,现已成为通信领域的研究热点.对无碰撞区跳频序列的理论界及其设计进行深入研究,导出无碰撞区跳频序列的一些本质属性;讨论无碰撞区跳频序列集周期汉明相关函数的理论界,揭示几个理论界之间的关系,给出这些理论界等价的条件.提出最优无碰撞区跳频序列的一般构造方法.利用该构造方法,可以产生任意长度的最优无碰撞区跳频序列集.并且,任意一个最优无碰撞区跳频序列集,都可以由一般构造方法产生.     

无碰撞区跳频/时序列理论界与设计

跳频(时)序列分析与设计是跳频(时)扩频通信系统的核心技术.无碰撞区跳频序列是近年新出现的一个研究方向,现已成为通信领域的研究热点.对无碰撞区跳频序列的理论界及其设计进行深入研究,导出无碰撞区跳频序列的一些本质属性;讨论无碰撞区跳频序列集周期汉明相关函数的理论界,揭示几个理论界之间的关系,给出这些理论界等价的条件.提出最优无碰撞区跳频序列的一般构造方法.利用该构造方法,可以产生任意长度的最优无碰撞区跳频序列集.并且,任意一个最优无碰撞区跳频序列集,都可以由一般构造方法产生.     

多时间序列求关联维D_2

在利用Ｇ．Ｐ．法由单一时间序列计算关联维Ｄ_２的基础上，引入矩阵范数，提出了多时间序列数据联合计算关联维Ｄ_２的算法。这一算法是Ｇ．Ｐ．法的推广。验算结果表明这一算法正确、可行，能提高计算结果的可靠性。     

MC-CDMA上下行链路扩频序列设计及仿真研究

分析了MC-CDMA上下行链路发送端的基带系统模型,给出了发送信号峰均功率比和用户扩频序列非周期自相关函数之间的关系,对上下行链路采用不同类型扩频序列集的PAPR性能进行了仿真.仿真结果表明在MC-CDMA的上下行链路中采用正交Golay序列均具有优异的PAPR性能,和常用基于walsh序列的MC-CDMA系统相比具有更强的实用意义.     

2种亚洲龙鱼的D—Loop序列结构分析

采用PCR技术对2种亚洲龙鱼的mtDNAD-Loop全序列进行扩增和测序，序列结构分析和序列同源性比对结果表明，2种亚洲龙鱼的mtDNAD-Loop在靠近5’端有3个终止相关序列TAS（Ⅰ、Ⅱ、Ⅲ），靠近D-Loop的3’端有4个保守区域CSB1、CSB2、CSB3、CSB—D。在终止相关序列和保守区域之间是连续重复区域。经DNASP4．0软件分析，全序列中检测出多态位点数（S）为26，其中有17个转换，核苷酸多样性（Pi）为0．013，平均核苷酸差异数（K）为17．333。     

2种亚洲龙鱼的D-Loop序列结构分析

采用PCR技术对2种亚洲龙鱼的mtDNAD_Loop全序列进行扩增和测序,序列结构分析和序列同源性比对结果表明,2种亚洲龙鱼的mtDNAD_Loop在靠近5’端有3个终止相关序列TAS(Ⅰ、Ⅱ、Ⅲ),靠近D_Loop的3’端有4个保守区域CSB1、CSB2、CSB3、CSB-D。在终止相关序列和保守区域之间是连续重复区域。经DNASP4.0软件分析,全序列中检测出多态位点数(S)为26,其中有17个转换,核苷酸多样性(Pi)为0.013,平均核苷酸差异数(K)为17.333。     

分组密码的安全性与强化设计

分组密码是数据通讯中最常用的数据加密方式，以DES为例分析现有分组加密算法的安全隐患，并提出了可变密钥加密和变长密文输出两个新思路，可应用于所有现有分组加密算法以提高安全性，并就该方法的安全性、效率、具体应用做出了分析。     

变质岩的变质序列分析──以辽河群为例

通过对辽河群岩石中主要变质矿物的观察和研究，以岩石的变形历史作为变质结晶作用的相对时标，确定了矿物生长的时序特征及其演化过程。发现变质与变形既是有密切联系的又是各自独立的地质作用，辽河期的变形作用存在明显的３个变形幕，而辽河期的变质作用是个连续的完整的过程，无明显的热波动。变质作用高峰和变形作用高峰存在时间差。     

基于不同产生机制的伪随机序列和DNA序列的随机性测量

随机序列在现代网络通信中起重要作用,而随机性是衡量随机序列好坏的关键。利用2种标准算法DES和AES及改进,实现基于TDES、3-TDES、AES以及3-AES 4种不同机制的伪随机数生成器,并利用DNA序列转换机制形成0-1序列。对所有序列进行单比特频数检测,通过P值形成分布直方图,采用相似性图示比较它们的分布特征。比较结果显示,3-AES生成的序列不显示更强的随机性,但DNA序列显示出良好的随机特性。     

Cloning and Analysis of Calmodulin Gene from Porphyra yezoensis Ueda (Bangiales, Rhodophyta)

In order to understand the mechanisms of signal transduction and anti-desiccation mechanisms of Porphyra yezoensiss,cDNA and its genomic sequence of Calmodulin gene (CaM) was cloned by the technique of polymerase chain reaction (PCR) based on the analysis of P. yezoensis ESTs from dbEST database. The result shows that the full-length cDNA of CaM consists of 603 bps including an ORF encoding for 151 amino acids and a terminate codon UGA, while the length of genomic sequence is 1231 bps including 2 exous and 1 intron. The average GC content of the coding region is 58.77%, while the GC content of the third position of this gene is as high as 82.23%. Four Ca2+ binding sites (EF-hand) are found in this gene. The predicted molecular mass of the deduced peptide is 16688.72 Da and the pI is 4.222. By aligning with known CaM genes, the similarity of CaM gene sequence with homologous genes in Chlamydomonas incerta and Chlamydomonas reinhardtii is 72.7% and 72.2% respectively, and the similarity of the deduced amino acid sequence of CaM gene with homologous genes in C. incerta and C. reinhardtii are both 71.5%. This is the first report on CaM from a species of Rhodophyta.     

Efficient expression of green fluorescent protein （GFP） mediated by a chimeric promoter in Chlamydomonas reinhardtii

To improve the expression efficiency of exogenous genes in Chlamydomonas reinhardtii, a high efficient expression vector was constructed. Green fluorescent protein （GFP） was expressed in C. reinhardtii under the control of promoters： RBCS2 and HSP70A-RBCS2. Efficiency of transformation and expression were compared between two transgenic algae： RBCS2 mediated strain Tran-Ⅰ and HSP70A-RBCS2 mediated strain Tran-Ⅱ. Results show that HSP70A-RBCS2 could improve greatly the transformation efficiency by approximately eightfold of RBCS2, and the expression efficiency of GFP in Tran-Ⅱ was at least double of that in Tran-Ⅰ. In addition, a threefold increase of GFP in Tran-Ⅱ was induced by heat shock at 40℃. All of the results demonstrated that HSP70A-RBCS2 was more efficient than RBCS2 in expressing exogenous gene in C. reinhardtii.     

Construction of Porphyra yezoensis Pure Line from Protoplasts and Its 18S rDNA Sequence Determination

The wild Porphyra yezoensis collected from the Qingdao coast was used to prepare protoplasts by enzyme digestion. The pure line was constructed by cultivating the protoplasts. The 18S rDNA of the P. yezoensis pure line was cloned and sequenced. Sequence analysis was executed for this sequence and other 22 sequences retrieved from GenBank. A phylogenetic tree was constructed using the neighbor-joining method. The results revealed a high diversity of 18S rDNA sequences in genus Porphyra and the considerable variation of 18S rDNA sequences in different strains of the same species P. yezoensis and P. tenera. Significant difference of 18S rDNA sequence was observed between P. yezoensis from Qingdao, China, and the two strains of P. yezoensis from Japan, but the three strains of P. yezoensis formed a stable clade in the phylogenetic tree. These results indicate the possibility of interspecies and intraspecies discrimination of Porphyra using the 18S rDNA sequences.     

Cloning and sequencing of the allophycocyanin genes fromSpirulina maxima (Cyanophyta)

The genes coding for the α-and β-subunit of allophycocyanin (apcA andapcB) from the cyanophyteSpirulina maxima were cloned and sequenced. The results revealed 44.4% of nucleotide sequence similarity and 30.4% of similarity of deduced amino acid sequence between them. The amino acid sequence identities betweenS. maxima andS. platensis are 99.4% for α subunit and 100% for β subunit.

     

Identification and characterization of a DnaJ gene from red alga <Emphasis Type="Italic">Pyropia yezoensis</Emphasis> (Bangiales,Rhodophyta)

Members of the DnaJ family are proteins that play a pivotal role in various cellular processes, such as protein folding, protein transport and cellular responses to stress. In the present study, we identified and characterized the full-length DnaJ cDNA sequence from expressed sequence tags of Pyropia yezoensis (PyDnaJ) via rapid identification of cDNA ends. This cDNA encoded a protein of 429 amino acids, which shared high sequence similarity with other identified DnaJ proteins, such as a heat shock protein 40/DnaJ from Pyropia haitanensis. The relative mRNA expression level of PyDnaJ was investigated using real-time PCR to determine its specific expression during the algal life cycle and during desiccation. The relative mRNA expression level in sporophytes was higher than that in gametophytes and significantly increased during the whole desiccation process. These results indicate that PyDnaJ is an authentic member of the DnaJ family in plants and red algae and might play a pivotal role in mitigating damage to P. yezoensis during desiccation.     

RAPD study on some common species ofPorphyra in China

Electroporation, PEC, PEG plus electroporation and Biolistics methods were tested in gene transformation ofP. yezoensis. The exogenousgus was from plasmid of pBI121 and pCAMBIA1301, both contain the CaMV35S promoter. The receptors included the protoplasts, tissues and free-living conchocelis filaments ofP. yezoensis. Several factors, for example, the voltage, capacitance and bivalent cations, etc., were studied. Results show that these four methods are all efficient for gene transformation inP. yezoensis; and that PEG is the best one, with transformation efficiency of up to 4×10⁻⁵. GUS activity was detected 26 days after transformation by using PEG method.

     

The Complete Sequence of Mitochondrial COⅡ Gene of Fenneropenaeus chinensis and Its Applicability as a Marker for Phylogenetic Analysis

The complete mitochondrial cytochrome oxidase subunit Ⅱ （COⅡ） gene of Penaeinae shrimp Fenneropenaeus chinensis was cloned and sequenced. The gene is 688 bp in length and codes for 229 amino acids. It shows 83.2%, 87.0% and 83.8% sequence similarity to Marsupenaeus Japonicus, Penaeus monodon and Farfantepenaeus notialis, respectively. The A＋T content of the whole gene and that at the third position of codons are 64.7% and 78.2%, respectively. The phylogenetic relationship between F. chinensis and three other species representing genera Farfanatepenaeus, Marsupenaeus and Penaeus was analyzed. Results showed that the genetic distances among the four taxa ranged from 0.144 0 to 0.200 5, exceeding those estimated with COⅠ and partial 16S rRNA gene sequences among Marsupenaeus, Litopenaeus and Melicertus, and being therefore larger than the value among subgenera. It has been suggested that the COⅡ gene has a faster evolutionary rate than that of the COⅠ gene and partial 16S rRNA gene and could be used for phylogenetic analysis at genus or species level. The results of the present study indicated that Farfantepenaeus, Fenneropenaeus, Marsupenaeus and Penaeus are at a higher phylogenetic level than subgenus, which supports the opinion of the elevation of phylogenetic status of the four subgenera to genus level.