OALib Journal期刊

ISSN: 2333-9721




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匹配条件: “HE Ren-Qing” ,找到相关结果约51906条。
An Example of Analyzing the Characteristics of a Large Scale ISP Topology Measured from Multiple Vantage Points

JIANG Yu,FANG Bin-Xing,HU Ming-Zeng,HE Ren-Qing,

软件学报 , 2005,
Abstract: A detailed understanding of the structural properties of Internet topology will benefit the further design and development of the Internet. It seems infeasible to study the whole Internet at router level due to its extremely large size and the difficulty in obtaining a whole topology at this level. Studying each national or continental Internet service provider (ISP) topology individually becomes an alternative method for this goal. In this paper, the measured China Education and Research Network topology, a nationwide ISP topology, is basically taken as an example. The results of mapping the topology from multiple vantage points are briefly presented. The properties of the degree distribution, large eigenvalues, and the spectral density of the measured topology graphs are analyzed. The characteristics of the signless Laplacian spectra (SLS), the normalized Laplacian spectra (NLS), and the clustering coefficients of the measured graphs are also presented. The results suggest that some power laws indeed hold in some large-scale ISP topologies; in contrast to the case of autonomous system level topologies, the power law fit is not the best choice for some ISP topologies in terms of the complementary cumulative distribution function of the degree; some real ISP topologies are a kind of scale-free graphs which are not consistent with the Barabási-Albert (BA) growth model; router level topologies are distinguishable in terms of the SLS or the NLS; router level Internet topology may have developed over time following a different set of growth processes from those of the BA model.
The Lauraceae Plants and Their Geographic Distribution in Shandong Province

Wang Ren-qing,

植物学报 , 1989,
Abstract: This paper reported the kinds of Lauraceae and their geographic distribution in Shandong Province. There are 5 genua and 8 species of Lauraceae which are mainly distributed in the mountain and hill area of Shandong peninsula as well as Central and Southern Shandong.
Implementation and improvement of auto gain control in the 3G mobile terminal

LIU Ren-qing,

重庆邮电大学学报(自然科学版) , 2011,
Abstract: 针对3G终端通话时语音不够平滑圆润的问题,提出在3G上行和下行语音链路中增加自动增益控制(automatic gain control,AGC)模块。AGC模块通过自适应更新增益值算法能够防止通话过程中的语音幅度过大,从而避免语音数据经过数字增益后发生溢出,同时能对小信号进行有效地放大,对时域语音质量进行均衡,使通话双方感到语音质量自然流畅。但是如果不对现有AGC算法进行改进,处理后的语音中会产生非线性失真。改进后的AGC不仅可以使输出语音的幅值在一个预先规定的范围内,根据预先设定的门限值,放大小信号,限制强信号,防止通话过程中的语音信号过载,同时能避免非线性失真。经过理论评估和实际验证,该模块能够有效地放大小信号,限制强信号,从而增强移动终端通话质量。
Identification of Genes to Differentiate Closely Related Salmonella Lineages
Qing-Hua Zou, Ren-Qing Li, Ye-Jun Wang, Shu-Lin Liu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0055988
Abstract: Background Salmonella are important human and animal pathogens. Though highly related, the Salmonella lineages may be strictly adapted to different hosts or cause different diseases, from mild local illness like gastroenteritis to fatal systemic infections like typhoid. Therefore, rapid and accurate identification of Salmonella is essential for timely and correct diagnosis of Salmonella infections. The current identification methods such as 16S rRNA sequencing and multilocus sequence typing are expensive and time consuming. Additionally, these methods often do not have sufficient distinguishing resolution among the Salmonella lineages. Methodologies/Principal Findings We compared 27 completely sequenced Salmonella genomes to identify possible genomic features that could be used for differentiation of individual lineages. We concatenated 2372 core genes in each of the 27 genomes and constructed a neighbor-joining tree. On the tree, strains of each serotype were clustered tightly together and different serotypes were unambiguously separated with clear genetic distances, demonstrating systematic genomic divergence among the Salmonella lineages. We made detailed comparisons among the 27 genomes and identified distinct sets of genomic differences, including nucleotide variations and genomic islands (GIs), among the Salmonella lineages. Two core genes STM4261 and entF together could unambiguously distinguish all Salmonella lineages compared in this study. Additionally, strains of a lineage have a common set of GIs and closely related lineages have similar sets of GIs. Conclusions Salmonella lineages have accumulated distinct sets of mutations and laterally acquired DNA (e.g., GIs) in evolution. Two genes entF and STM4261 have diverged sufficiently among the Salmonella lineages to be used for their differentiation. Further investigation of the distinct sets of mutations and GIs will lead to novel insights into genomic evolution of Salmonella and greatly facilitate the elucidation of pathogeneses of Salmonella infections.
Study on Camellia japonica Poperties of Vegetation Pattern
中国分布北界的山茶(Camellia japonica)种群大小结构和空间格局分析

ZHANG Zhi-Guo,WANG Ren-Qing,

植物生态学报 , 2000,
Abstract: 青岛沿海地区是山茶在中国分布的最北界。长门岩岛是该地区山茶的主要分布地。岛上的山茶集中分布在海拔20~80m的范围内,植株的胸径为2~45cm,高度0.4~4.5m。由生命表可以看出,属于小个体级与大个体级的数目较少,大多数个体处于中级水平。从大小金字塔看,它属于Bodenheimer所述的下降型种群。存活曲线图表明,小个体级的死亡率较高。应用泊松分布、负二项分布和奈曼分布3种理论分布模型,进行了分布格局的研究,结果表明,该种群的实际频数符合负二项分布,由此判定种群的分布格局为聚集分布。通过对种群的聚集强度指数的计算,求得各参数分别为二项参数(K)0.6291,扩散系数(C)17.7372,丛生指标(I)16.7372,Cassie指标(1/K)1.5896,聚块性指标为(m*/m)2.5896,均表明为强聚集分布。
Benzyl 5-phenylpyrazolo[5,1-a]isoquinoline-1-carboxylate
Yu-Kun Lu,Xiao Yao,Li-Wen Luo,Ren-Qing
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536811050586
Abstract: In the title compound, C25H18N2O2, the pyrazolo[5,1-a]isoquinoline ring system is approximately planar [maximum deviation = 0.027 (2) ] and is oriented at dihedral angles of 57.22 (6) and 71.36 (7)° with respect to the two phenyl rings. The phenyl rings are twisted to each other by a dihedral angle of 66.33 (8)°. A weak intramolecular C—H...O hydrogen bond occurs. In the crystal, weak C—H...π interactions are present.
Poly[[(4,4′-bipyridine-κN)[μ3-(S)-2-hydroxybutanedioato-κ4O1,O2:O4:O4′]zinc] dihydrate]
Yu-Kun Lu,Jian Liu,Cheng-Lin Diao,Ren-Qing
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536811045788
Abstract: In the title compound, {[Zn(C4H4O5)(C10H8N2)]·2H2O}n, the ZnII ion displays a distorted tetragonal–pyramidal coordination environment with one hydroxy O and three carboxylate O atoms from three malate anions, and the one remaining position occupied by an N atom from a 4,4′-bipyridine ligand. The pyridine rings of the 4,4′-bipyridine ligand are twisted with respect to each other by a dihedral angle of 35.8 (2)°. The uncoordinated water molecules are linked to the complex molecules by O—H...O hydrogen bonds. Each malate anion forms four coordination bonds with three Zn atoms, establishing a layer structure parallel to the ac plane. Adjacent layers are further linked via O—H...N hydrogen bonding. π–π stacking between the pyridine rings [face-to-face distance = 3.651 (3) ] occurs in the crystal structure.
Developments in Microcosm Research

CHAO Min,WANG Ren-Qing,YAO Hong-Yan,

植物学报 , 1999,
Abstract: Microcosm research has a long history in ecology, which can simulate the pre-designed results conveniently and precisely, and with the characteristic of simplicity and small-size. It has been a widely used means for studying the principles and methods in ecology. This paper describes the recent developments in microecosestem research, and analyses its status and role in ecology.
Models and strategies of ecological city construction

LU Min,WANG Ren-Qing,LI Ying-Jie,

中国生态农业学报 , 2007,
Abstract: Ecological city is man's ideal residence model in the new century.The paper summarized five main models of ecological city.The models include circulating economic ecological city,political ecological city,complex economic ecological city,ecological resource ecological city and seashore ecological city.Finally,strategies and basic contents and measures of ecological city construction are advanced.
Bis[tris(ethylenediamine-κ2N,N′)cobalt(III)] octakis-μ-3-oxido-hexadeca-μ2-oxido-tetradecaoxido-μ12-tetraoxosilicato-octamolybdenum(VI)hexavanadium(IV,V) hexahydrate
Yu-Kun Lu,Ming-Ming Tian,Shu-Gang Xu,Ren-Qing
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536811048197
Abstract: The title compound, [Co(C2H8N2)3]2[SiMo8V4O40(VO)2]·6H2O, was prepared under hydrothermal conditions. The asymmetric unit consists of a transition metal complex [Co(en)3]3+ cation (en is ethylenediamine), one half of an [SiMo8V4O40(VO)2]6 heteropolyanion, two solvent water molecules in general positions and two half-molecules of water located on a mirror plane. In the complex cation, the Co3+ ion is in a distorted octahedral coordination environment formed by six N atoms of the three chelating en ligands. One of the en ligands exhibits disorder of its aliphatic chain over two sets of sites of equal occupancy. The [SiMo8V4O40(VO)2]6 heteropolyanion is a four-electron reduced bivanadyl-capped α-Keggin-type molybdenum–vanadium–oxide cluster. In the crystal, it is located on a mirror plane, which results in disorder of the central tetrahedral SiO4 group: the O atoms of this group occupy two sets of sites related by a mirror plane. Furthermore, all of the eight μ2-oxide groups are also disordered over two sets of sites with equal occupancy. There are extensive intermolecular N—H...O hydrogen bonds between the complex cations and inorganic polyoxidoanions, leading to a three-dimensional supramolecular network.

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