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Periodicity of Retzius lines in fossil Pongo from South China

Chinese Science Bulletin 2012年第7期57卷 790-794页

作者： HU Rong1,2,3, ZHAO LingXia1,2 & WU XinZhi2 1 Key laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of sciences, beijing 100044, China 2 laboratory of Human Evolution, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of sciences, beijing 100044, China 3 Graduate University of Chinese Academy of sciences, beijing 100049, China laboratory of Human Evolution Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Beijing 100044 China

Periodicity of Retzius lines is a key factor in dental development. In this study, we examined the periodicity of Retzius lines in fossil Pongo from South China using polarized light microscope observation of dental ground sections. The periodicities all of the 15 teeth were 9 d. Comparisons of periodicity were made with extant primates, fossil apes and hominins. Periodicity of fossil Pongo from South China was relatively long but fell within the variation of extant Pongo, Gorilla and modern human, and longer than periodicity of Pan and other extant primates. Fossil Pongo from South China was similar to Lufengpithecus and Sivapithecus, shorter than Gigantopithecus and longer than European and African fossil apes and most early hominins in periodicity. Generally, the periodicities of Asian large-body fossil apes were longer than the periodicities of European and African large-body fossil apes in Miocene. Difference among species and trend of evolution in periodicity were analyzed and discussed. We found that periodicity might gradually increase from Proconsul in early Miocene to several fossil apes in Miocene and then Gigantopithecus in Pleistocene. In addition, this study made correlate analysis between periodicity and body mass respectively in males and females of six extant apes and five fossil apes, and found that periodicity positively correlated with body mass.

关键词：周期性变化中国南方大猩猩化石灵长类动物早中新世类人猿显微镜观察

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On the ratio of different norms of caloric functions and related eigenfunctions of an integral operator

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Science China Mathematics 2012年第8期55卷 1597-1612页

作者： DING YuTao 1,2,& ZHANG LiQun 1,2 1 Institute of Mathematics,Academy of Mathematics and Systems Science,Chinese Academy of sciences,beijing 100190,China 2 Hua Loo-Keng Key laboratory of Mathematics,Chinese Academy of sciences,beijing 100190,China 1. Institute of Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China2. Hua Loo-Keng Key Laboratory of Mathematics Chinese Academy of Sciences Beijing 100190 China

We investigate the ratio of L 1 and L 2 norms of the Cauchy problem solutions of heat equations with compact support initial *** related asymptotic behavior of the eigenvalues and eigenfunctions of certain integral op... 详细信息

关键词： integral operators eigenvalues heat equation

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Dynamic tree-based authenticated group key exchange protocol

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Science China(Information sciences) 2010年第8期53卷 1591-1602页

作者： LI Hui 1,2 , WU ChuanKun 1 & TENG JiKai 1,2 1 State Key laboratory of Information Security, Institute of Software, Chinese Academy of sciences, beijing 100190, China 2 Graduate University of Chinese Academy of sciences, beijing 100049, China 1. State Key laboratory of Information Security Institute of Software Chinese Academy of Sciences Beijing 100190 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Authenticated group key exchange protocols allow a group of users over a public network to establish a shared secret key for the subsequent cryptographic goals. In this paper, we extend BD-II scheme into a dynamic setting, and propose a tree-based authenticated key exchange protocol which is more suitable for dynamic groups in such as ad hoc networks. Our protocol is proven secure in random-oracle model. Additionally, we analyze the costs of our protocols in both communication and computation terms, and compare its performance with three well-known protocols.

关键词： tree-based group key exchange dynamic provable security

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Photodissociation/photoionization processes of chlorobromomethane induced by femtosecond laser pulses with pump-probe scheme

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Chinese Science Bulletin 2008年第5期53卷 681-686页

作者： ZHANG Feng1,2, WEI ZhengRong1,2, CAO ZhenZhou1,2, ZHANG ChangHua1,2 & ZHANG Bing1,2 1 State Key laboratory of Magnetic Resonance and Atomic and molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of sciences, Wuhan 430071, China 2 Graduate University of Chinese Academy of sciences, beijing 100039, China State Key laboratory of Magnetic Resonance and Atomic and molecular Physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan China Graduate University of Chinese Academy of sciences Beijing China

The photodissociation/photoionization processes of chlorobromomethane (CH_2BrCl) induced by fem- tosecond laser pulses have been investigated using pump-probe scheme combined with the time-of-flight mass spectra. The dominate photoproducts are observed at different delay time of the pump (400 nm) and probe (800 nm) pulses and the corresponding time-dependence of them is obtained. The results show that the decaying time of the molecule CH_2BrCl in the A-band is in the 100 fs. The decaying tendencies of the fragment ions (CH_2Cl^+ and CH_2Br^+) and the parent ion (CH_2BrCl^+) are almost the same and the relative ratios of the yields of them keep constant during the delay time of 0 to 150 fs. These facts suggest that the fragment ions come from the fragmentation of the parent ions in excited electronic states. The probabilities to form CH_2Cl^+ and CH_2Br^+ are obtained from the relative ratio of the ion intensity and are about 71.6% and 14.2%, respectively.

关键词：毫微秒激光氯溴化甲烷激光探针光解作用光化电离作用

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TRANSIENT EFFECT OF A BOGER FLUID FLOWING AROUND A CONFINED CYLINDER

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Chinese Journal of Polymer Science 2001年第4期19卷 377-384页

作者： Xian-feng Li Huai-tian Bu De-lu Zhao State Key laboratory of Polymer Physics and Chemistry Center for molecular Science,Institute of Chemistry, Chinese Academy of sciences, beijing 100080, China Chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Polymer Phys & Chem Beijing 100080 Peoples R China

This paper is concerned with the numerical simulation of the transient effect of an inertialess Boger flow past a confined circular cylinder and the comparison of predictions with particle image velocimetry (PIV) measurements given by Shiang et al.. Dynamic simulation based on the Oldroyd-B constitutive model was carried out using a Lagrangian-Eulerian algorithm. The evolution of velocity field was obtained for the flow at two Deborah (De) numbers, i.e. De = 1.2 and 3.0. At low De, the flow reached steady state rapidly, and showed a symmetric flow regime. However, at high De, the time required to reach steady flow behind the cylinder increased significantly, and the distribution of the velocity field appears to be asymmetric with respect to the stagnation line. Fairly good agreement between the numerical results and the experimental observations is reported. It can be concluded that both the experimental measurements and the present simulations indicate that the elasticity of the polymeric flow strongly affect the flow regime of viscoelastic flow around a confined cylinder.

关键词： transient effect flow around a cylinder Lagrangian-Eulerian algorithm Oldroyd-B model

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Genomic organization and sequence analysis of the vomeronasal receptor V2R genes in mouse genome

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Chinese Science Bulletin 2007年第3期52卷 336-342页

作者： YANG Hui1,2 & Zhang YaPing1,3 1 laboratory of Cellular and molecular Evolution, Kunming Institute of Zoology, Chinese Academy of sciences, Kunming 650223, China 2 Graduate University of the Chinese Academy of sciences, beijing 100049, China 3 laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming 650091, China laboratory of Cellular and molecular Evolution Kunming Institute of ZoologyChinese Academy of Sciences Kunming 650223 China

Two multigene superfamilies, named V1R and V2R, encoding seven-transmembrane-domain G-protein coupled receptors (GPCRs) have been identified as pheromone receptors in mammals. Three V2R gene families have been described in mouse and rat. Here we screened the updated mouse genome se- quence database and finally retrieved 63 putative functional V2R genes including three newly identified genes which formed a new additional family. We described the genomic organization of these genes and also characterized the conservation of mouse V2R protein sequences. These genomic and se- quence information we described are useful as part of the evidence to speculate the functional domain of V2Rs and should give aid to the functionality study in the future.

关键词：大白鼠基因组犁鼻受体2 多基因超家族序列分析

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Interfacial behaviors of PMMA-PEO block copolymers at the air/water interface

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Science China Chemistry 2005年第6期48卷 567-573页

作者： CHENG Caixia1, JIAO Tifeng2, TANG Rupei1, LIU Minghua2 & XI Fu1 1. State Key laboratory of Polymer Physics and Chemistry, Joint laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of sciences, beijing 100080, China 2. CAS Key laboratory of Colloid and Interface Science, Institute of Chemistry, Chinese Academy of sciences, beijing 100080, China 1. State Key laboratory of Polymer Physics and Chemistry Joint Laboratory of Polymer Science and Materials Institute of Chemistry Chinese Academy of Sciences 100080 Beijing China 2. CAS Key laboratory of Colloid and Interface Science Institute of Chemistry Chinese Academy of Sciences 100080 Beijing China

Diblock copolymer of PMMA291-b-PEO114 and triblock copolymer of PMMA120-b- PEO227-b-PMMA120 were synthesized and their interfacial properties at the air-water interface were investigated, where both blocks of polyethylene oxide (PEO) and poly(methyl methacrylate) (PMMA) are surface active but the former is soluble in water while the latter is not. Both the block copolymers could form monolayers with two obvious transition regions. The first transition point is around 10 mN/m, which could be assigned to the pancake-brush change of the PEO chains. The other is around 18 mN/m, which could be ascribed to the condensed packing of PMMA. The surface morphological changes during the compression of the Langmuir monolayers are inves-tigated by using the AFM and SEM methods for the films deposited at different surface pressure or molecular areas. At a lower surface pressure, a typical morphology of PEO-con- taining lipopolymers is observed. Upon compression, sphere-dominant morphologies were observed. While the diblock copolymer is easy to folding, the triblock copolymer is in favor of formation of circular domains through vesiculation.

关键词： PMMA-PEO, block copolymers, monolayer, Langmuir-Blodgett films, AFM.

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Inertial theory of the mean Hadley circulation under the condition of nonstatic equilibrium

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Science China Earth sciences 2006年第5期49卷 546-553页

作者： CHAO Jiping1 & LIU Fei2,3 1. national Marine Environmental Forecasting Center, beijing 100081, China 2. Key laboratory Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of sciences, beijing 100029, China 3. Graduate University of Chinese Academy of sciences, beijing 100049, China 1. national Marine Environmental Forecasting Center Beijing 100081 China 2. Key laboratory Regional Climate-Environment for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 3. Graduate University of Chinese Academy of sciences Beijing 100049 China

Tropical atmosphere is divided into two layers, the layer near the ground is the planet boundary layer, where the motion is linear, if the radiation equilibrium temperature is given at the top of the boundary layer, the vertical motion there can be obtained. It is the non-viscous ideal atmos- pheric layer above the boundary one, where the motion is nonlinear. After getting the conservation laws of angular momentum, potential temperature and potential vortex, the inertial theory of the Hadley circulation driven by the vertical motion of the boundary layer is established, followed by sev- eral examples of its application.

关键词： Hadley circulation, inertial theory, conservation laws of angular momentum, potential temperature and potential vortex.

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Relaxation of Chain Extension of Amorphous PET Fiber Above the Glass Transition Temperature

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Chinese Chemical Letters 2000年第10期11卷 925-928页

作者： Xin LINGHU, Jun ZHAO, Rui SONG, Qing Rong FAN (Polymer Physics laboratory, Center of molecular Science, Institute of Chemistry, Chinese Academy of sciences, beijing, 100080) Polymer Physics laboratory Center of Molecular Science Institute of Chemistry Beijing 100080 China

The recovery of amorphous PET fiber in global chain orientation but nearly random segmental orientation (GOLR) state was studied by the hot shrinkage measurement above the glass transition temperature. The relaxation curves in the form of di-exponential decay were acquired and the change of two special times with the variation of treating temperature and residual recovery ratio ' was discussed.

关键词： GOLR state PET recovery of chain extension hot shrinkage measurement.

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Characteristics and geological significance of olivine xenocrysts in Cenozoic volcanic rocks from western Qinling

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Progress in Natural Science:Materials International 2006年第12期16卷 1300-1306页

作者： SU Benxun~ 1,2 **, ZHANG Hongfu~1, XIAO Yan~ 1,2 and ZHAO Xinmiao~ 1,2 (1. State Key laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of sciences, beijing 100029, China 2. Graduate School of Chinese Academy of sciences, beijing 100039, China) [a]State Key laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China [b]Graduate School of Chinese Academy of sciences Beijing China

Cenozoic volcanic rocks from the Haoti, Dangchang County of the western Qinling Mountains, contain a few clearly-zoned olivines. These olivines are relatively big in grain sizes and usually have cracks or broken features. Their cores have similar compositions （Mg#=90.4-91.0） to those for the peridotitic xenoliths entrained in host volcanic rocks and their rims are close to the compositions of olivine phenocrysts （Mg#=85.5-81.9）. The CaO contents in these zoned olivines are lower than 0.1%. These features demonstrate that the clearly-zoned olivines are xenocrysts and disaggregated from mantle peridotites. The zoned texture was the result of the interaction between the olivine and host magma. Available data show that the volcanic rocks would have been derived from the mantle source metasomatized by subducted hydrathermally-altered oceanic crust. The formation of these Cenozoic volcanic rocks was perhaps related to the rapid uplift of the Tibetan Plateau.

关键词： Western Qinling Dangchang Haoti Cenozoic volcanic rocks olivine xenocrysts zoned texture.

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