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A Note on the Uniqueness of Koebe–Andreev–Thurston Theorem

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Acta Mathematica Sinica,English Series 2012年第7期28卷 1469-1474页

作者： xiao Jun HUANG Zi peng WANG College of Mathematics and Statistics Chongqing University

In this paper, we present a new proof of the uniqueness of Koebe-Andreev-Thurston theorem. Our method is based on the argument principle in complex analysis and reviews the connection between the circle packing theore... 详细信息

关键词： Circle packing argument principle MSbius transformation

Acquisition probability differences in cloud coverage of the available Landsat observations over mainland Southeast Asia from 1986 to 2015

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International Journal of Digital Earth 2018年第5期11卷 437-450页

作者： peng Li Zhiming Feng Chiwei xiao Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijingPeople’s Republic of China College of Resources and Environment University of Chinese Academy of SciencesBeijingPeople’s Republic of China

Landsat data are the longest available records that consistently document global ***,the extent and degree of cloud coverage typically determine its usability,especially in the *** this study,scene-based metadata from the *** Survey Landsat inventories,ten-day,monthly,seasonal,and annual acquisition probabilities(AP)of targeted images at various cloud coverage thresholds(10%to 100%)were statistically analyzed using available Landsat TM,ETM+,and OLI observations over mainland Southeast Asia(MSEA)from 1986 to *** significant results were ***,the cumulative average acquisition probability of available Landsat observations over MSEA at the 30%cloud cover(CC)threshold was approximately 41.05%.Second,monthly and ten-day level probability statistics for the 30%CC threshold coincide with the temporal distribution of the dry and rainy *** demonstrates that Landsat images acquired during the dry season satisfy the requirements needed for land cover ***,differences in acquisition probabilities at the 30%CC threshold are different between the western and eastern regions of ***,the ability of TM,ETM+,and OLI to acquire high-quality imagery has gradually enhanced over time,especially during the dry season,along with consequently larger probabilities at lower CC thresholds.

关键词： Landsat cloud coverage(CC) acquisition probability(AP) mainland Southeast Asia land cover and land use changes

Synthesis,Crystal Structure and Bioactivity Evaluation of a Heterocyclic Compound

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Chinese Journal of Structural Chemistry 2020年第10期39卷 1892-1897,1745页

作者： ZHANG peng ZHAO xiao-Mei School of Pharmacy Shaanxi University of Chinese MedicineXianyangShaanxi 712046China

The heterocyclic compound 2-amino-N-(2-chloro-6-methylphenyl)thiazole-5-carboxamide(1),designed using 2-chloro-6-methylaniline(2)as the start material,was successfully obtained via multiple synthesis route and finally characterized by IR,1H NMR,and single-cystal X-ray *** select the suitable candidates for tissue regeneration,the induction activity of the compound on the dental pulp mesenchymal stem cells(DP-MSCs)was ***,the DP-MSCs cells were isolated and the cell colon formation ability was measured after compound treatment with cell colony *** that,the RT-PCT assay was conducted and the relative expression level of the genes related with cell osteogenesis and proliferation was further detected.

关键词： heterocycles X-ray DP-MSCs RT-PCT assay

Split Quasi-adequate Semigroups

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Acta Mathematica Sinica,English Series 2012年第2期28卷 425-438页

作者： xiao Jiang GUO Ting Ting peng Department of Mathematics Jiangxi Normal UniversityNanchang 330022P.R.China Department of Base Jiangxi V&T College of CommunicationNanchang 330013P.R.China

The so-called split IC quasi-adequate semigroups are in the class of idempotent-connected quasi-adequate semigroups. It is proved that an IC quasi-adequate semigroup is split if and only if it has an adequate transversal. The structure of such semigroup whose band of idempotents is regular will be particularly investigated. Our obtained results enrich those results given by McAlister and Blyth on split orthodox semigroups.

关键词： Quasi-adequate semigroup adequate semigroup adequate transversal regular band,type-A semigroup

Coordinative Development Between Land Use Change and Regional Population-Resources-Environment-Development System—A Case Study of Jiangsu Province

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Chinese Geographical Science 2007年第4期17卷 289-296页

作者： xiao Sisi HUANG Xianjin peng Buzhuo School of Geographic ＆ Oceanographic Sciences Nanjing University Nanjing 210093 China

Land use change has significant influence on the operation of the PopulationResources-Environment-De-velopment (PRED) System. Moderate land use is the key factor to ensure the coordinative and sustainable development between land use and PRED system. Based on the internal relationship between land use and PRED system, a PRED evaluation index system and a Press-Status-Response (PSR) model were established in this study. According to the expounding on the mechanism of the PSR model, we investigated the coordinative development between the changes of regional land use and PRED system taking Jiangsu Province as an example. The results showed that the orders of the Synthetic Index of Land Use (SILU) and the Variation of PRED Index (VPI) in Jiangsu are both the southern Jiangsu>the central Jiangsu>the northern Jiangsu. A cubic curve model was used to fit the relationship between the VPI and SILU. The inflection point of VPI was situated in 5.0 of SILU. When SILU was below 5.0, VPI increased with SILU, which will be helpful to the coordinative development between land use and PRED system. Based on those results, it is suggested that the land use degree of the southern Jiangsu, especially that of Nanjing City, should be moderately controlled at present, while land resources of the central Jiangsu and the northern Jiangsu should be further exploited.

关键词： land use change Population-Resources-Environment-Development (PRED) system Press-Status-Response (PSR) model coordinative development Jiangsu Province China

Circular Polarization in Pulsar Integrated Profiles: Updates

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Chinese Journal of Astronomy and Astrophysics 2006年第2期6卷 237-246页

作者： xiao-peng You Jin-lin Han National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

We update the systematic studies of circular polarization in integrated pulse profiles by Han et al. Data of circular polarization profiles are compiled. Sense reversals can occur in core or cone components, or near the intersection between components. The correlation between the sense of circular polarization and the sense of position angle variation for conal-double pulsars is confirmed with a much large database. Circular polarization of some pulsars has clear changes with frequency. Circular polarization of millisecond pulsars is marginally different from that of normal pulsars.

关键词： polarization - pulsars: general

Carbon isotopic compositions of 1,2,3,4-tetramethylbenzene in marine oil asphaltenes from the Tarim Basin:Evidence for the source formed in a strongly reducing environment

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Science China Earth Sciences 2008年第4期51卷 509-514页

作者： JIA WangLu peng PingAn xiao ZhongYao State Key Laboratory of Organic Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Tarim Oilfield Company PetroChinaKorla 841000China

Although 1-alkyl-2,3,6-trimethylbenzenes and a high relative amount of 1,2,3,4-tetramethylbenzene have been detected in marine oils and oil asphaltenes from Tabei uplift in the Tarim Basin, their bio-logical sources are not determined. This paper deals with the molecular characteristics of typical ma-rine oil asphaltenes from Tabei and Tazhong uplift in the Tarim Basin and the stable carbon isotopic signatures of individual compounds in the pyrolysates of these asphaltenes using flash pyrolysis-gas chromatograph-mass spectrometer (PY-GC-MS) and gas chromatograph-stable isotope ratio mass spectrometer (GC-C-IRMS), respectively. Relatively abundant 1,2,3,4-tetramethylbenzene is detected in the pyrolysates of these marine oil asphaltenes from the Tarim Basin. δ 13C values of 1,2,3,4-tetrame-thylbenzene in the pyrolysates of oil asphaltenes vary from-19.6‰ to-24.0‰, while those of n-alkanes in the pyrolysates show a range from-33.2‰ to-35.1‰. The 1,2,3,4-tetramethylbenzene in the pyro-lysates of oil asphaltenes proves to be significantly enriched in 13C relative to n-alkanes in the pyro-lysates and oil asphaltenes by 10.8‰―15.2‰ and 8.4‰―13.4‰, respectively. This result indicates a contribution from photosynthetic green sulfur bacteria Chlorobiaceae to relatively abundant 1,2,3,4-tetramethylbenzene in marine oil asphaltenes from the Tarim Basin. Hence, it can be speculated that the source of most marine oil asphaltenes from the Tarim Basin was formed in a strongly reducing water body enriched in H2S under euxinic conditions.

关键词： 1 2 3 4-tetramethylbenzene asphaltenes marine oils the Tarim Basin carbon isotopic composition

A temporal context model for boosting video annotation

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Science China(Information Sciences) 2013年第11期56卷 92-105页

作者： YI Jian peng YuXin xiao JianGuo Institute of Computer Science and Technology Peking University

In this paper,we propose a new method to model the temporal context for boosting video annotation *** motivation of our idea mainly comes from the fact that temporally continuous shots in video are generally with relevant content,so that the performance of video annotation could be comparably boosted by mining the temporal dependency between shots in *** on this consideration,we propose a temporal context model to mine the redundant information between *** connecting our model with conditional random feld and borrowing the learning and inference approaches from it,we could obtain the refned probability of a concept occurring in the shot,which is the leverage of temporal context information and initial output of video *** with existing methods for temporal context mining of video annotation,our model could capture diferent kinds of shot dependency more accurately to improve the video annotation ***,our model is relatively simple and efcient,which is important for the applications which have large scale data to *** experimental results on the widely used TRECVID datasets exhibit the efectiveness of our method for improving video annotation accuracy.

关键词： video annotation temporal context conditional random feld video retrieval

Compound jet generated from an impacted concave dual-layer liquid surface

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Journal of Hydrodynamics 2021年第2期33卷 390-394页

作者： Xiang-gang Cheng xiao-peng Chen School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China

By impacting a concave dual-layer liquid(with the oil and the dyed water)surface in a test tube,a compound jet with a water core and an oil shell is *** velocities of the jet's head(Vj)and the oil-water interface(Vj')are experimentally determined against the initial thickness and the viscosity of the upper layer *** results show that the oil-water interface can be roughly regarded as a pure material surface,whose velocity can be determined from the jet velocity and the initial location(or the film thickness).Furthermore,the effective density,viscosity and surface tension of the compound jet are used to evaluate the jetting *** previous scaling relation for a single liquid jet can be used to give a good prediction with the effective *** results of this paper can be used for the compound jet/droplet preparation.

关键词： Compound jet dual-layer liquid viscosity interface tension