丁广义割圆序列的线性复杂度

Minimal polynomials and linear complexity of binary Ding generalized cyclotomic sequences of order 2 with the two-prime residue ring Zpq are obtained by Bai in 2005. In this paper, we obtain linear complexity and minimal polynomials of all Ding generalized cyclotomic sequences. Our result shows that linear complexity of these sequences takes on the values pq and pq-1 on our necessary and sufficient condition with probability 1/4 and the lower bound （pq - 1）/2 with probability 1/8. This shows that most of these sequences are good. We also obtained that linear complexity and minimal polynomials of these sequences are independent of their orders. This makes it no more difficult in choosing proper p and q.     

截断情形下污染分布的非参数估计

设X1，X2，…，Xn是一列iid随机变量，其分布为Fα(t)=（1-α）F1t) αF2（t)，其中：α∈[0,1]，F1(t),F2(t)都是定义在R^1上的分布函数，在下列条件下：（1）上述污染数据又被另一iid的随机变量序列u1,u2,… ,u3截断；（2）F2（x)分布已知；（3）存在某个可测函数M（x)，使μ1=∫M(s)dF1(x)已知，构造出了α和F1（x)的估计。并证明了其强相合性。     

关于AR-MA双重时序模型平稳解的存在性

本文在参考文献[1]、[2]的基础上讨论了AR-MA双重时序模型存在平稳解的条件,获得了AR(1)-MA(1)和AR(1)-MA(2)存在平稳解的充要条件(不必假定白噪声序列为正态)。本文的方法完全适用于讨论一般的AR(1)-MA(q)模型的平稳解的存在性,而且对讨论AR-AR模型也有所启发。     

论新闻的价值根源、构成序列和实现条件

人与新闻的关系是新闻活动的总关系,人与新闻间的价值关系是总关系中的根本关系。新闻的价值就是新闻对人的价值,对由人构成的社会的价值,归根结底则是新闻对人作为主体的效用或意义。新闻的价值根源于新闻作为事实信息的本质属性,根源于作为人之基本需要的新闻需要。信息价值是新闻的本原价值、第一价值,新闻的其他价值项目(价值项)作为派生价值或延伸价值都应建立在本原价值基础之上。新闻的价值实现需要一定的社会环境条件、需要专业化的新闻生产传播方式以及合理正确的新闻解读。     

美梦还是陷阱?——论数据科学背景下的档案数据管理

数据科学解决的是海量数据的快速处理和精准分析等问题,而档案数据管理在数据量急速增长的现实环境中,亟须新技术、新方法和新理念来减轻海量数据处理的负担,数据科学的相关技术和思维在一定程度上为档案数据管理突破“困局”提供了便利。数据科学影响下档案数据管理的突破口(1)数据分析和加工技术促进档案数据管理的“有序化”。依靠数据加工和数据分析技术,庞杂无序的档案数据可以在最短的时间内呈现相互关联、有序的状态,使得档案数据管理获得关联清晰、逻辑清晰、价值清晰的数据序列,为档案数据的进一步加工、利用奠定坚实的数据基础。     

图书借阅流量行为季节预测模型

指出图书借阅流量行为预测是图书借阅行为学的一个重要研究方向,常规的借阅流量预测大多采用的是ARIMA时间序列模型,但普通时间序列预测模型的参数难以估计并且模型较难处理非平稳时间序列问题。基于时间序列的神经图书借阅模型研究是,根据图书借阅流量行为的季节性特点,提出季节型神经图书借阅模型。用模型对图书借阅流量行为的预测分析表明,该模型预测效果较好,结果合理,对进行图书借阅实时监控及图书借阅管理都具有一定的理论和实践价值。     

Scaling behavior of nucleotide cluster in DNA sequences

In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the scaling behavior of P（S） ∝ e^-αs＇ where S represents nucleotide cluster size. The cluster-size distribution P（S1＋S2） with the total size of sequential C-G cluster and A-T cluster S1＋S2 were also studied. P（S1＋S2） follows exponential decay. There does not exist the case of large C-G cluster following large A-T cluster or large A-T cluster following large C-G cluster. We also discuss the relatively random walk length function L（n） and the local compositional complexity of nucleotide sequences based on a new model. These investigations may provide some insight into nucleotide cluster of DNA sequence.     

<Emphasis Type="Italic">Mrakia psychrophila</Emphasis> sp. nov., a new species isolated from Antarctic soil

The yeast strain （Y18） was isolated from a soil sample collected from Fildes Peninsula, Antarctica. The strain is a psychrophilic yeast with optimum and maximum growth temperatures of 10 ℃ and 18 ℃, respectively. Teliospores were formed after 7 d on malt agar, when the germination of teliospores was observed. Both inositol and D-glucuronate were assimilated. Positive results of the DBB （diazonium blue B） color reaction, urease test, and starch formation were observed. The major CoQ is Qs. All results indicated that Y18 belongs to the genes of Mrakia. The 18S rDNA sequence analyses showed that Y18 is closely related to Mrakiafrigida. DNA-DNA relatedness study, and some biochemistry characteristics indicated that Y18 represents a new species for which Mrakia psychrophila sp. nov. is proposed.     

基因工程中工具酶的有关问题解答

<正>1限制性核酸内切酶是如何命名的?怎样理解其识别序列的特异性和切割位点的特异性?限制性核酸内切酶的命名,目前主要以Smith和Nathans的命名系统为基础,     

对“群落的演替”一节教学内容理解的四个把握

<正>"群落的演替"一节的教学中,教师如何能让学生在客观分析群落演替的过程上正确对待群落演替的概念,准确区分初生演替和次生演替?对以下四个方面的把握很关键。1对群落演替概念的理解要把握住"因演而替的主体过程"人教版新教材中对群落演替的定义为:随着时间的推移,一个群落被另一个群落代替的过程。这一概