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Identifying Functional Modules in Complex Networks

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Communications in Theoretical Physics 2007年第5X期48卷 957-960页

作者： li Ke-ping State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing 100044 China

In this paper, we propose a new method that enables us to detect and describe the functional modules in complex networks. Using the proposed method, we can classify the nodes of networks into different modules according to their pattern of intra- and extra-module links. We use our method to analyze the modular structures of the ER random networks. We find that different modules of networks have different structure properties, such as the clustering coefficient. Moreover, at the same time, many nodes of networks participate different modules. Remarkably, we find that in the ER random networks, when the probability p is small, different modules or different roles of nodes can be Mentified by different regions in the c-p parameter space.

关键词： complex networks modular structure clustering coefficient

p73β inhibits transcriptional activities of enhancer I and X promoter in hepatitis B virus more efficiently than p73α

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World Journal of Gastroenterology 2002年第6期8卷 1094-1097页

作者： Tsai-ping li State Key Laboratory of Molecular Biology Institute of Biochemistry and Cell BiologyShanghai Institutes for Biological SciencesChinese Academy of SciencesShanghai 200031China

AIM: p73, as a novel member of a family of p53-related transcription factors, shares redundant functions with p53, such as the abilities of inducing apoptosis and suppressing growth. It is well known that p53 can repress HBV expression and transcription efficiently. The aim of this paper is to investigate the transcriptional effect of p73α and p73β on hepatitis B virus (HBV) and to understand the correlation between HBV and ***: To construct an x-gene inactivated HBV plasmid which was cotransfected with p73α or p73β expression vectors into HepG2 cells. After transiently transfecticn, HBV surface antigen (HBsAg) and HBV e antigen (HBeAg) were detected by EliSA. Viral transcripts synthesized by HBV were evaluated by Northern blotting analysis. The activities of HBV regulatory elements, including enhancer Ⅰ/X promoter (ENI/Xp) and enhancer Ⅱ/core promoter (ENⅡ/Cp) were monitored by luciferase ***: Both p73α and p73β could repress HBsAg and HBeAg expression by downregulating the ENⅠ/Xp and ENⅡ/Cp activities. But p73β exerted stronger inhibition on the activity of ENI/Xp than p73α, resulting in much lower level of viral transcripts and the antigens ***: p73β as a novel member of p53 family can efficiently inhibit HBV transcription mainly through downregulating the activities of the HBV ENI/Xp regulatory elements.

关键词： B肝病毒 I增强子 X启动子转录活性 p73β 抑制作用 p73α

Car Deceleration Considering Its Own Velocity in Cellular Automata Model

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维普期刊数据库

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Communications in Theoretical Physics 2006年第1期45卷 113-116页

作者： li Ke-ping Key Laboratory of Intelligent Technologies and Systems of Traffic and Transportatipn Beijing Jiaotong UniversityBeijing 100044 China

In this paper, we propose a new cellular automaton model, which is based on NaSch traffic model. In our method, when a car has a larger velocity, if the gap between the car and its leading car is not enough large, it will decrease. The aim is that the following car has a buffer space to decrease its velocity at the next time, and then avoid to decelerate too high. The simulation results show that using our model, the ear deceleration is realistic, and is closer to the field measure than that of NaSch model.

关键词： cellular automaton traffic flow fundamental diagram

Assessing the factors impacting the bioaccessibility of mercury(Hg) in rice consumption by an in-vitro method

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Journal of Environmental Sciences 2022年第9期34卷 119-129页

作者： Ze Wu ping li Xinbin Feng College of Eco-Environmental Engineering Guizhou Minzu UniversityGuiyang 550025China Key Laboratory of Environmental Pollution Monitoring and Disease Control Ministry of EducationGuizhou Medical UniversityGuiyang 550025China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China

Mercury(Hg) in rice is drawing mounting concern since methylmercury(MeHg) was found capable of accumulating in rice. In-vitro bioaccessibility is a feasible and reliable method to assess the health effects of Hg in rice and has been utilized in a number of studies. This study was done to investigate the impact of cultivar, planting location, and cooking on the total mercury(THg) and MeHg bioaccessibility of rice, for which multiple statistical analysis methods were used to analyze the significance of their effects. The THg concentrations of rice samples taken from non-Hg contaminated areas of China were all below 15 ng/g and their MeHg concentrations were below 2 ng/g. Cooking could significantly reduce the MeHg bioaccessibility of rice because the MeHg was mainly combined with protein and the protein will be denatured during the cooking process, and then the denatured MeHg is difficult to be dissolved into the liquid phase. Indica-and japonica-type rice cultivars did not show significant differentiation in either the concentration of Hg or its bioaccessibility. However, the glutinous rice type differed significantly from the above rice types, and it showed greater bioaccessibility of THg and MeHg due to its distinct protein contents and starch properties. Planting location can affect the Hg concentration in rice and THg bioaccessibility but has a limited impact on MeHg bioaccessibility. Based on these results, two macro factors(rice cultivar, planting location) are presumed to impact Hg bioaccessibility by how they affect micro factors(i.e., Hg forms).

关键词： Rice Bioaccessibility Mercury Impact factors

Morphological and microscopic characterization of five commonly-used testacean traditional Chinese medicines

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Acta Pharmaceutica Sinica B 2015年第4期5卷 358-366页

作者： Ying Xu Wei Song ping Zhou ping li Huijun li State Key Laboratory of Natural Medicines China Pharmaceutical University

Testacean traditional Chinese medicine(TTCM), derived from the outer shell of sea or freshwater mollusks, is a special and important category of Chinese medicinal materials. To ensure the effective use of TTCM, a comparative identification study was performed on five commonly-used testacean drugs, including Haliotidis Concha, Arcae Concha, Meretricis Concha, Ostreae Concha and Margaritifera Concha(Shijueming, Walengzi, Geqiao, Muli and Zhenzhumu in Chinese, respectively).Typical morphological photographs of the crude drugs were acquired, and the key microscopic characteristics of the derived powders under normal light microscope and polarized light microscope were summarized. The major results can be concluded as follows:(1) the original species involved in the five TTCMs could be distinguished by their respective interspecies morphological characteristics;(2) the key identification characteristics of the five powdered crude drugs were mainly crystal fragments, with the fragment features under both normal light and polarized light microscope providing powerful points for differentiating the five commonly-used testacean drugs. This study demonstrated that it is feasible to provide authentication for these five kinds of TTCMs by the combination of morphology with microscopy.

关键词： Testacean traditional Chinese medicine Morphological characteristics Microscopic characteristics Normal light microscopy Polarized light microscopy

Preparation and anti atomic oxygen erosion properties of OPPOSS/PI composites

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International Journal of Minerals,Metallurgy and Materials 2013年第10期20卷 994-1000页

作者： Wei-ping li Hui-cong liu li-li Feng School of Materials Science and Engineering Beihang University Key Laboratory of Urban Stormwater System and Water Environment (Ministry of Education) Beijing University of CivilEngineering and Architecture

Atomic oxygen （AO） found in low earth orbit can cause serious erosion to polyimide （PI） materials, which greatly limits their lifetime. 8-phenyl silsesquioxane （OPPOSS） was synthesized, and OPPOSS/PI composites were pre- pared by physical blending, followed by thermal imidization to enhance the AO erosion resistance of PI materials. The morphology, composition, and structure of the composites were analyzed before and after AO exposure in a ground sim- ulated facility of atomic oxygen. After 16 h AO exposure, the OPPOSS/PI composite with 5wt% OPPOSS addition shows an erosion rate of about 1.4×10-24 cm3/atom with only 48% mass loss of that of PI without OPPOSS addition. The mixture of OPPOSS nano molecules is assembled into a kind of regular square structure and distributed evenly in OPPOSS/PI composites. Some SiO2 particles are formed in the composites during AO exposure, which can act as ＂inert points＂ to reduce the AO erosion rate of OPPOSS/PI composites.

关键词： composite materials polyimides silsesquioxanes atomic oxygen erosion

The Signature of Generalized Flag Manifolds and Applications

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Acta Mathematica Sinica,English Series 2010年第8期26卷 1457-1462页

作者： ping li Yang SU Department of Mathematics Tongji University Shanghai 200092 P. R. China Institute of Mathematics Academy of Mathematics and System Science Chinese Academy of Sciences Beijing 100190 P. R. China

Let G be a linear algebraic group over C and P be a parabolic subgroup. We determine the signatures of the flag manifold G/P. As an application, we prove that the nonsingular hypersurfaces of degree 2 in CP^n are prim... 详细信息

关键词： Signature flag manifold prime manifold

Synthesis, Crystal Structure, Thermal Stability and Solid UV-Vis Absorption Spectra of One New Copper(Ⅱ) Coordination Polymer

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Chinese Journal of Structural Chemistry 2019年第9期38卷 1537-1542页

作者： XUE li-ping College of Food and Drug Luoyang Normal University

A new coordination polymer [Cu2(OH)(nbta)(tib)(H2 O)2]n(1, H3 nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, tib = 1-(4 H-1,2,4-triazol-4-yl)-4-(imidazol-1-yl)benzene) constructed from dimeric Cu(Ⅱ) units has been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction analysis. The compound crystallizes in monoclinic system, space group I2/c, with a = 17.8474(9), b = 11.7588(6), c = 21.9221(11) ?, β = 104.419(5)°, V = 4455.7(4) ?3 and Z = 8. Compound 1 is a three-dimensional structure constructed from dimeric Cu(Ⅱ) units and presents a 2-nodal(3,5)-connected net. Moreover, the thermal stability and solid UV-Vis absorption spectra have been investigated.

关键词： copper coordination polymer crystal structure topology UV–Vis absorption spectra

Unitary space vector quantization codebook design for spatial correlated limited feedback MIMO system

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The Journal of China Universities of Posts and Telecommunications 2008年第1期15卷 23-27页

作者： WU ping li li-hua Key Laboratory of Universal Wireless Communications Beijing University of Posts and Telecommunications Ministry of Education Wireless Technology Innovation Institute (WTI) Beijing I00876 China

In the transmitting, beamforming, and receiving combing （TBRC） MIMO system, a codebook based feedback strategy is usually used to provide the transmitter with the beamforming vector. The adopted codebook affects the system performance considerably. Therefore, the codebook design is a key technology in the TBRC MIMO system. In this article, the unitary space vector quantization （USVQ） codebook design criterion is proposed to design optimal codebooks for various spatial correlated MIMO channels. And the unitary space K-mean （USK） codebook generating algorithm is provided to generate the USVQ codebooks. Simulations show that the capacities of the feedback based TBRC systems using USVQ codebooks are very close to those of the ideal cases.

关键词： USVQ multiple-input multiple-output (MIMO) system TBRC