D.H.Lehmer问题中数列的伪随机性

伪随机二进制数列在密码学中扮演着重要的角色,D.H.Lehmer问题是数论中一个非常重要的问题.郭晓艳给出D.H.Lehmer问题的一个推广,由此生成一种新的伪随机二进制数列,并研究了其一致分布测度、2阶相关测度和2阶联合测度.利用解析方法讨论了更一般的情况,即研究了其l阶相关测度和l阶联合测度.     

On <Emphasis Type="Italic">k</Emphasis>-error linear complexity of some explicit nonlinear pseudorandom sequences

Combining with the research on the linear complexity of explicit nonlinear generators of pseudorandom sequences, we study the stability on linear complexity of two classes of explicit inversive generators and two classes of explicit nonlinear generators. We present some lower bounds in theory on the k-error linear complexity of these explicit generatol＇s, which further improve the cryptographic properties of the corresponding number generators and provide very useful information when they are applied to cryptography.     

Speeding up implementation for Shor’s factorization quantum algorithm

In this paper, based on the implementation of semiclassical quantum Fourier transform, we first propose the concept of generation vector of ternary binary representation, construct the generation function’s truth table, prove that the generation vector of ternary binary representation is one kind of k ’s NAF representation and further find that its number of nonzero is not more than [(⌈log k⌉ + 1)/2]. Then we redesign a quantum circuit for Shor’s algorithm, whose computation resource is approximately equal to that of Parker (Their requirements of elementary quantum gate are both O(⌈logN⌉³), and our circuit requires 2 qubits more than Parker’s). However, our circuit is twice as fast as Parker’s.     

NO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> reduction by coupling combustion with recycling flue gas in iron ore sintering process

A new process called ‘NO _x reduction by coupling combustion with recycling flue gas (RCCRF)’ was proposed to decrease NO _x emission during the iron ore sintering process. The simulation test of NO _x reduction was performed over sintered ore and in the process of coke combustion. Experimentally, NO _x reduction was also carried out by sintering pot test. For sintered ore, the amount of NO _x emission is reduced by 15wt%–25wt% at 400–550°C using 2.0vol% H₂ or 2.0vol% CO, or reduced by 10wt%–30wt% at 560–720°C using 0.15vol% NH₃. NO _x reduction is around 10wt% by coupling combustion of pyrolysis gas and coke, or around 16wt% by recycling flue gas into coke combustion. By RCCRF, the maximum NO _x reduction ratio is about 23wt% in coke combustion experiment and over 40wt% in sintering pot test.     

Experimental validation of inter-subspecific genetic diversity in rice represented by the differences between the DNA sequences of ＇Nipponbare＇ and ＇93-11＇

The pedigrees of three sequenced rice cultivars were analyzed to show that a majority of the genetic composition of ＇Nipponbare＇ originates from japonica cultivars while the minority originates from indica cultivars. In contrast, ＇93-11＇ is derived mainly from indica cultivars with a smaller contribution from japonica cultivars. All ancestors of ＇Guang lu ai 4＇ appeared to be indica lines. A set of molecular markers （46 InDels and 53 SSRs） polymorphic between ＇Nipponbare＇ and ＇93-11＇ were examined in 46 typical indica and 47 typical japonica cultivars selected from 443 accessions according to Cheng＇s index. All cultivars were divided into indica and japonica groups without overlapping when clustered by Cheng＇s index, InDels and SSRs. Much higher InDel and SSR diversity between groups than within groups implies that the marker polymorphisms between ＇Nipponbare＇ and ＇93-11＇ represent a large proportion of inter-subspecific diversity. About 85% of indica cultivars and more than 90% of japonica cultivars were confirmed to have the same PCR banding patterns as ＇93-11＇ and ＇Nipponbare＇, respectively. Some polymorphic loci between ＇Nipponbare＇ and ＇93-11＇ cannot be validated in other indica and japonica cultivars, either as subspecies-specific but not predominant alleles, or alleles not specific between the two groups. It was concluded that molecular markers developed from sequence polymorphism between ＇Nipponbare＇ and ＇93-11＇ often represent inter-subspecific diversity, although some exceptions were sensitive to either particular marker loci or particular cultivars.     

循环椭圆曲线耦合一致分布混沌映射的混合图像加密算法研究

由于当前的Logistic混沌映射无法满足一致分布,且在混沌区域存在空白窗口,使得混沌区域较小,在利用该映射加密图像时,导致了较小的密钥空间,降低了加密系统的安全性。因此,定义了一个循环椭圆曲线,设计了一致分布Logistic混沌映射和伪随机混合密钥流生成器,再根据混沌方程与循环椭圆曲线,构造一个加密函数,提出了循环椭圆曲线与一致分布Logistic混沌映射相融合的图像加密算法。首先,根据一致分布Logistic混沌映射和256位的外部密钥以反馈模式生成初始密钥流;然后利用循环椭圆曲线产生的伪随机位序列混合初始密钥流,得到伪随机混合加密数据流;最后根据加密函数对图像进行加密。借助MATLAB仿真平台,对算法及其他几种加密系统进行了对比仿真分析。结果表明:与当前的Logistic映射相比,设计的混沌映射具有更好的一致分布行为;与其他几种加密算法相比,具有更好的加密质量;且密钥空间巨大。     

A study of bacterial linear growth using a microcalorimetric method

By using an LKB-2277 bioactivity monitor, we have determined the thermogenesis curves of four kinds of anaerobes linear growth. From the thermogenesis curves, we established the growth thermokinetic equation: dP/dt=k _m·P ⁿ , the order of growth metabolismn=0, and calculated the mean specific rate constant of multiplication {ie95-1}. It is a new kind of bacterial growth, it was compared with exponential growth. Liu Yi: born Nov. 1970. Ph. D. Curent research interest is in biothermochemistry research Supported by the National Natural Science Foundation of China     

低相关区屏蔽序列偶集的构造

将伪随机屏蔽序列偶应用于低相关区(LCZ)序列偶集的构造中,提出一种低相关区屏蔽序列偶集的构造方法.基于伪随机屏蔽序列偶,通过不同的移位序列和正交矩阵,采用交织方法生成具有一定长度、序列偶数目和低相关区长度的LCZ屏蔽序列偶集,对构造方法进行了理论证明和举例说明.该构造方法也可基于广义伪随机屏蔽二进序列偶构造LCZ屏蔽...     

Antibacterial activity and structure-activity relationships of Schiff bases on <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> by microcalorimetry

The growth of Staphylococcus aureus under the action of six kinds of Schiff bases(A,B,C,D,E,F) was studied by means of microcalorimetry. Growth constant k and inhibition ratio I were calculated. Also,the antibacterial activity,the action characteristics and the structure-activity relationships of the compounds on S. aureus were analyzed. Results indicate that B,F show good antibacterial activity(IC50:293.6 mg · L-1 and 307.8 mg · L-1) ,D,E show moderate antibacterial activity(IC50:966.3 mg · L-1 and 1 126.7...     

Synoptic-scale variation of δ18O in summer monsoon rainfall at Lijiang, China

Based on the daily δ~(18)O data in June―September 2003 at Lijiang and the daily mean NCEP/ NCAR reanalysis data, synoptic-scale variation of δ~(18)O in summer monsoon rainfall was investigated. The 'precipitation amount effect' is obvious for the daily δ~(18)O variation, whereas the 'temperature effect' is insignificant. Alternate occurrences of active phase and break phase of the southwest monsoon probably influence the synoptic-scale δ~(18)O variation prominently. Moreover, the isotopic composition in precipitation during the late monsoon months is presumably influenced significantly by recycling of monsoon precipitation. Both the above factors disturb the 'amount effect' of isotopic variation in the monsoon region. This study also indicates that the synoptic-scale rainfall δ~(18)O variation at Lijiang in summer is domi-nated by the Indian monsoon depression (low pressure) system at large scale. These results are important for further studying the 'amount effect' and reconstructing paleoclimate in the monsoon region.     

An osmundaceous rhizome with sterile and fertile fronds and <Emphasis Type="Italic">in situ</Emphasis> spores from the Jurassic of western Liaoning

A well-preserved permineralized osmundaceous fern was discovered from the Middle Jurassic Tiaojishan Formation of Beipiao, Liaoning Province, China. The rhizome is about 50 cm high and 35–41 cm in diameter and can be attributed to the genus Ashicaulis on the basis of its anatomy. The sterile pinnae are referable to Cladophlebis, the fertile pinnules are of the Todites type with in situ spores of the Osmundacidites type. Osmundaceous rhizomes have been found all over the world including the Jurassic strata of western Liaoning, China. Until now, however, no rhizomes have been reported to be organically connected with leafy organs. Although impressions and compressions of isolated osmundaceous sterile and fertile fronds are common, they were described under separate organ- or morpho-generic names, such as Todites and Cladophlebis. The new discovery provides an opportunity to study an osmundaceous fern in ‘whole plant concept’ to learn more about its morphology and structure, and the paleoclimatic and paleoenvironmental requrirements of this group.     

Self-assembly of two-dimensional DNA crystals

Self-assembly of synthetic oligonucleotides into two-dimensional lattices presents a 慴ottom-up?approach to the fabrication of devices on nanometer scale. We report the design and observation of two-dimensional crystalline forms of DNAs that are composed of twenty-one plane oligonucleo-tides and one phosphate-modified oligonucleotide. These synthetic sequences are designed to self-assemble into four double-crossover (DX) DNA tiles. The 憇ticky ends?of these tiles that associate according to WatsonCrick抯 base pairing are programmed to build up specific periodic patterns upto tens of microns. The patterned crystals are visualized by the transmission electron microscopy.     

Prediction of β -turns using double BP network with novel coding schemes of amino acids

Protein structure prediction is one of the most important problems in structural biology. β-turns are always at the turn of a protein tertiary structure and thus β-turn’s prediction is a key step in tertiary structure prediction. There are some methods to predict β-turns based on machine learning techniques such as k-nearest method, neural networks and support vector machine. In this paper, we construct a classifier using double BP networks and put forward two novel methods to code amino acids in the second network. When trained and tested on different datasets, they achieve more accuracy than other coding methods.      

Strong Law of Large Numbers and Complete Convergence for Sequences of φ-Mixing Random Var, ables

We give some theorems of strong law of large numbers and complete convergence for sequences of φ-mixing random variables. In particular, Wittmann＇s strong law of large numbers and Teicher＇s strong law of large nnumbers for independent random variables are generalized to the case of φ -minxing random variables.     

相互偶合作用下混沌系统的同步

过对混沌系统的驱动变量进行相互偶合,使不同初值下的混沌系统达到同步。同步过程不改变原系统的混沌性质。在一定的偶合强度ｋ２下,对Ｌｏｒｅｎｚ混沌系统进行了数值实验,结果在ｋ２＞２的情况下,系统都达到了同步。这一偶合强度明显小于主动被动同步方法中的偶合强度。最后,我们对主动被动同步方法、连续反馈同步方法及相互偶合变量同步方法进行了比较,发现在一定的条件下,三种同步方法具有等价的关系。     

Statistical Characteristics of the Complexity for Prime-Periodic Sequences

Using the fact that the factorization of x^N-1 over GF(2) is especially explicit, we completely establish the distributions and the expected values of the linear complexity and the k-error linear complexity of the N-periodic sequences respectively, where N is an odd prime and 2 is a primitive root modulo N. The results show that there are a large percentage of sequences with both the linear complexity and the k-error linear complexity not less than N, quite close to their maximum possible values.     

Binary Sequences from a Pair of Elliptic Curves

A family of binary sequences were constructed by using an elliptic curve and its twisted curves over finite fields. It was shown that these sequences possess ＂good＂ cryptographie properties of 0-1 distribution, long period and large linear complexity. The results indicate that such se quences provide strong potential applications in cryptography.     

Explicit classification for torsion cyclic subgroups of rational points with even orders of elliptic curves

For elliptic curves E over the rationals Q, the classification according to their torsion subgroups E_tors,(Q) of rational points has been studied. When E_tors, (Q) are cyclic groups with even orders, the classification is given with explicit critria, and the generators of the torsion groups are also explicitly presented in each case. These results, together with the recent results of Ono for the non-cyclic torsion groups, have completely solved the problem of the explicit classification withE being a rational point of order 2.     

椭圆曲线上的一类线性递归序列

试图寻找一种新的源序列发生器,即基于有限域的椭圆曲线上的线性递归序列。本文给出了椭圆曲线的Pe阶循环子群H上的本原多项式的定义、计数;给出了H上的极大长序列的周期,初态的计数及极大长圈的计数。