Molecular evolution of connective tissue growth factor in Cyprinidae （Teleostei： Cypriniformes）

Connective tissue growth factor （CTGF） plays an important role in regulation of cell growth, differentiation, apoptosis and individual development in animals. The study of sequences variation and molecular evolution of CTGF gene across various species of the cyprinid could be helpful for understanding of speciation and gene divergence in this kind of fish. In this study, 19 novel sequences of CTGF gene were obtained from the representative species of the family Cyprinidae using PCR amplification, cloning and sequencing. Phylogenetic relationships of Cyprinidae were reconstructed by neighbor-joining （NJ）, maximum parsimony （MP）, maximum likelihood （ML） and Bayesian method. Oryzias latipes from the family Cyprinodontidae was assigned to be the outgroup taxon. Leuciscini and Barbini were clustered into the monophyletic lineages, respectively, with the high nodal supports. The estimation of the ratio of non-synonymous to synonymous substitution （dN/dS） for the various branches indicated that there stood the different evolution rates between the Leuciscini and the Barbini. With the ratio of dN/dS of the Leuciscini being lower than that of the Barbini, species within the Barbini were demonstrated to be subjected to the relatively less selection pressure and under the relaxable evolution background. A 6 bp indel （insertion/deletion） was found at the 5＇ end of CTGF gene of Cyprinidae, and this 6 bp deletion only appeared in the Leuciscini, which is a typical characteristic of the Leuciscini and provides evidence for the monophylogeny of the Leuciscini. For the amino acid sequences of CTGF protein, the most variations and indels were distributed in the signal region and IGFBP region of this protein, implying that these variations were correlated with the regulation of the CTGF gene expression and protein activity.     

含天然微裂缝变形介质油藏数值模拟方法

在微裂缝油藏开发过程中，油藏流体压力的上升或下降会导致微裂缝的张开或闭合，油藏的绝对渗透率随之发生变化，而且微裂缝的存在使油藏渗透率呈现较强的各向异性，从而影响油藏的开发，针对这些特性，分析了微裂缝的存在对油藏绝对渗透率大小和主轴方向的影响，建立了含天然微裂缝低渗透油藏的三维、三相数学模型及数值模拟模型，并在此基础上研制出了油世故模拟软件，运用该软件进行了典型油藏单元的实例计算。结果表明，开采初期微裂缝油藏日产油量比常规油藏高，而后期则比常规油藏低，且采出程度总比常规油藏高。     

Reconstructing Native American population history

The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved. One contentious issue is whether the settlement occurred by means of a single migration or multiple streams of migration from Siberia. The pattern of dispersals within the Americas is also poorly understood. To address these questions at a higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. Here we show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call 'First American'. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan speakers on both sides of the Panama isthmus, who have ancestry from both North and South America.     

Photo-physical Characterisation of Novel Organic Dye-doped Solid-state Laser Materials

1 Results The development of tuneable solid-state organic dye lasers is a subject of considerable interest and research activity.Compared to conventional liquid dye lasers they have the advantage of being free of solvent handling,having small size,and being easy to operate.For high-performance solid-state dye lasers highly photo-stable dyes with low quantum yield of triplet formation and low triplet-triplet absorption cross-section in the lasing wavelength region are required.For solid state dye lasers organic molecules have been incorporated in inorganic glasses (mainly sol-gel glasses),in organic polymer matrices,and into hybrid compositions of inorganic-organic hosts.Here samples of the BODIPY dye (dipyrromethene-BF2 dye) PM597 incorporated in copolymers resembling inorganic-organic hybrid matrices are characterized by optical spectroscopic methods towards their application as solid-state laser rods.The inorganic function is entered by the constituent 3-(trimethoxysilyl)propyl methacrylate (TMSPMA).The organic constituents are monomers with one polymerizable group [methyl methacrylate (MMA),or 2-hydroxyethyl methacrylate (HEMA)],two [ethylene glycol dimethacrylate (EGDMA)],three [pentaerythriol triacrylate (PETA)],and four [pentaerythriol tetraacrylate (PETRA)] polymerizable groups.The copolymers were obtained by radical bulk polymerization with 2,2'-azobis(isobutyronitrile) (AIBN) as polymerization initiator.TMSPMA and MMA were also copolymerized by "in-situ" and simultaneous hydrolysis-condensation of the methoxy groups of TMSPMA during the free radical polymerization of MMA using AIBN in order to fully approach a sol-gel inorganic glass-organic polymer hybrid solid-state dye laser material.Structural and thermo-mechanical studies (thermogravimetry,differential scanning calorimetry,and infrared spectroscopy) revealed the highest thermo-mechanical stability for high-degree inter-crossing copolymerisation [COP(TMSPMA-PETA),COP(TMSPMA-PETRA)] and hydrolysis-polymerization [COPH(MMA-TMSPMA)].Concerning the optical spectroscopy characterisation,all studied PM597 doped copolymer samples exhibited high fluorescence quantum yields (60 % to 70 %),negligibly small excited-state absorption cross-sections (5% to 10 % of ground-state absorption at 527 nm),and high photo-stability (typically up to 3 million excitation cycles before degradation after some initial fading).The laser properties of the PM597 doped copolymers were evaluated by transversal pumping with 6 ns laser pulses of 5.5 mJ energy at 532 nm.Most of the studied samples surpassed 100 000 laser shots with no or only less than 50 % of laser output power reduction.     

拟三维全组分模型

本文提出了一个适合我国凝析油气藏模拟计算的拟三维模型，即多层二维三相全组分模拟器。采用有限差分方法和隐式压力、显式饱和度和显式组成的方法求解该模型。模型中还引进了包括六个油气状态方程（即PR、SRK、RT、SW、LLS及SHBWR）的相平衡闪蒸分析方法和物性参数计算方法。它可用于凝析油气藏一类油气田的开发设计和动态预测。文章还对凝析藏的衰竭及循环注气开采过程进行了实例模拟计算，并获得了满意的结果。     

气藏压裂水平井产能预测新方法

根据流体力学理论和动量定理 ,结合气体的性质和实际气体的状态方程 ,建立了气藏压裂水平井地层渗流和水平井筒管流耦合的计算模型 ,并给出了模型的求解方法。运用该模型对长庆油田低渗气藏进行了实际计算 ,同时分析了井筒半径、水平段长度、裂缝条数以及管壁粗糙度等参数对井筒压力损失和压裂水平气井产能的影响。计算结果表明 ,水平井筒内的压力损失对压裂水平气井的生产动态有一定的影响 ;水平井内每条压裂缝的产量并不相等 ,端部裂缝的产气量高于中部裂缝的产气量 ;水平井筒内的压力呈不均匀分布 ,从指端到根端压力逐渐降低     

What is Going on in a Critical Thermosyphon?

IntroductionWell- known optical phenomena in fluids in thethermodynamic critical state are the disappearanceof the meniscus between liquid and vapour phaseand the existence of a“critical opalescence”.　 This opalescence is observed as bluish inreflected…     

稠油油藏注CO_2吞吐适应性研究

以辽河油田的高升、冷家堡油藏为例 ,运用数值模拟和油藏工程方法对稠油油藏注CO2 吞吐进行了适应性研究 .研究表明 :原油黏度是影响CO2 吞吐效果最敏感的参数 ,随原油黏度增大 ,换油率增大 ,可以选择原油黏度较高的油藏进行CO2 吞吐 ;对于有一定自然产能的油藏来说 ,含油饱和度并非越高越好 ,而是有一定的适应范围 ;对于普通稠油 ,随原油黏度改变 ,合适的含油饱和度、孔隙度范围随之改变 .作出了普通稠油的黏度—含油饱和度图版、黏度—孔隙度图版 ,同时结合油田实际作出了两种不同标准的经济适应性图版 .所得的结果对辽河稠油油藏选择合适的CO2 吞吐井有一定的指导意义     

Hyperbranched Organometallic Polyynes :Optical and Thermal Properties and Their Transformation into Soft Ferromagnetic Ceramics

1Introduction Organometallic polymers have emerged as a group of interesting materials due to their useful catalytic,optical, electrical, sensing, and magnetic properties inaccessible by their pure organic parents. It is therefore highly desirable to utilize this class of high performance macromolecules for the preparation of micro- and nanosized patterns by photolithographic techniques and as precursors for advanced ceramics[1].