海洋贝类Toll样受体及其接头蛋白MyD88的分子进化研究

海洋贝类在长期的进化过程中具备了复杂和独特的免疫体系,为免疫防御系统的适应性进化研究提供了典型实例.目前海洋贝类天然免疫系统经典分子在后生动物演化历程中的特点尚不明确.为探究模式识别受体Toll样受体(TLR)及其接头分子髓样分化因子(MyD88)基因家族在后生动物中的进化历程,研究了32个后生动物演化代表性物种中TL...     

Mega-debris flow deposits from the Oligo-Miocene Pindos foreland basin, western mainland Greece: implications for transport mechanisms in ancient deep marine basins

The turbidite dominated, Oligo-Miocene Pindos foreland basin of western mainland Greece contains two thick (60–72 m), matrix supported conglomerates. The conglomerates are ungraded and contain three clast types: (1) polymict, rounded, extrabasinal clasts (long axes 3–50 cm); (2) tightly folded, intrabasinal clasts (long axes 1–10 m); and (3) tabular, largely undeformed, intrabasinal blocks (long axes 18–300 m). Clasts are isolated within a slit dominated matrix. These chaotic, matrix supported conglomerates are interpreted as mega-debris flow deposits. During transport, extrabasinal clasts were supported by a combination of matrix cohesion and clast dispersive pressure, folded intrabasinal clasts were supported by a combination of buoyancy (Archimedes principle) and clast dispersive pressure. The large tabular clasts were transported by gravity sliding/gliding within the flow on films at high pore fluid pressure. These different clast support mechanisms were active simultaneously within the Pindos mega-debris flow deposits. As a result, the deposits have no systemic vertical stratigraphy, in contrast to many described large scale mass flow deposits. The mega-debris flow deposits are significantly thicker than most described ancient siliciclastic debris flow deposits and provide an ancient analogue for the thick Recent siliciclastic debris flow deposits on continental margins.     

香港坪洲岛坪洲组中钙芒硝假晶的确定及其成因探讨

本文通过野外地质调查、显微鉴定分析、EPMA测试和 X射线分析 ,确定香港坪洲岛坪洲组地层中的方沸石、锥辉石和次生方解石等矿物部分是交代原始盐类矿物钙芒硝形成的 ,它们多以集合体方式构成钙芒硝假晶 ,具有钙芒硝的棱面体形态 ,并可以和区域上含钙芒硝的盐系地层进行对比。本文认为 ,原始钙芒硝为上述矿物的形成提供了 Na2 O和 Ca O,热液活动带来了部分 Si O2 ,通过交代蚀变作用形成了丰富的钙芒硝假晶。这一研究成果表明 ,坪洲组是一盐系地层 ,大鹏湾盆地在晚白垩世—古近纪时期是一演化程度较高的硫酸盐型蒸发岩盆地。     

MEASUREMENTS OF PARTICLE NUMBER SIZE DISTRIBUTIONS AND NEW PARTICLE FORMATION EVENTS DURING WINTER IN THE PEARL RIVER DELTA REGION, CHINA

Particle number size distribution(PNSD) between 10 nm and 20 μm were measured in the Pearl River Delta(PRD) region in winter 2011.The average particle number concentration of the nucleation mode(10-20 nm),Aitken mode(20-100 nm),accumulation mode(100 nm-1μm) and coarse mode(1-20 μm) particles were 1 552,7 470,4 012,and 19 cm-3,respectively.The volume concentration of accumulation mode particles with peak at 300 nm accounted for over 70% of the total volume concentration.Diurnal variations and dependencies on meteorological parameters of PNSD were investigated.The diurnal variation of nucleation mode particles was mainly influenced by new particle formation events,while the diurnal variation of Aitken mode particles correlated to the traffic emission and the growth process of nucleation mode particles.When the PRD region was controlled by a cold high pressure,conditions of low relative humidity,high wind speed and strong radiation are favorable for the occurrence of new particle formation(NPF) events.The frequency of occurrence of NPF events was 21.3% during the whole measurement period.Parameters describing NPF events,including growth rate(GR) and source rate of condensable vapor(Q),were slightly larger than those in previous literature.This suggests that intense photochemical and biological activities may be the source of condensable vapor for particle growth,even during winter in the PRD.     

中国大中城市流动人口迁移规律研究

本文在对西方国家人口流动研究进行综述的基础上,通过北京,天津,南京,廓坊,唐山和昆山等大中城市流动人口问卷调查,首次对大中城市流动人口迁移和流动特征,从业结构,迁移原因与途径进行了系统的研究。中国现在正在经历大规模的农村流动人口向城市迁移的过程。