Distribution,sources and ecological risk assessment of PAHs in surface sediments from Guan River Estuary,China

The contamination of surface sediments in Guan River Estuary, China, by polycyclic aromatic hydrocarbons (PAHs) has been fully investigated. Total concentrations of 21 PAHs ranged from 90 to 218 ng/g with an average of 132.7 ng/g, which is relatively low in comparison with other estuaries around the world. PAH concentrations appeared to be positively correlated with clay content and negatively correlated with sediment grain size. Source identification implied that the PAHs originated mainly from pyrolytic sources. However, source patterns may be continuously changed to a petrogenic origin due to the heavy ship traffic and continuous discharge of oily sewage in this area. The PAH levels were also compared with international Sediments Quality Guidelines and Sediments Quality Criteria, and the results indicated low negative effects for most individual PAHs. However, toxic effects related to FLO would occur occasionally in most locations in the estuary.     

20世纪古生物学的重大进展及21世纪战略重点

20世纪人类积累了大量的生物学、分类学和生物地层数据，这些数据的积累使用进化论和门德尔遗传学结合起来，如遗传学和物种起源、分类学和物种起源、演化的速率和模式、分支系统学等的运用使得古生物学在研究方法上有了新的进展。并提出了21世纪古生物学的战略重点。     

MCI技术及其在塔中47油藏油源对比中的应用

流体包裹体成分分析技术(MCI)是应用分子有机地球化学参数研究烃类包裹体成分的一种方法。它与常规技术相比具有三个显著优点:可以分析包裹体内烃类组成,达到分子级水平;使用化学试剂氧化处理包裹体表面污染物,避免高温操作影响流体包裹体烃类组成;空白实验贯穿全过程以确保包裹体的清洁性。该技术能够成功解决源岩、成熟度、油气充注期次及油气二次蚀变等问题。选取塔中47井石炭系和志留系的两块样品进行了MCI分析,取得正构烷烃、萜烷、甾烷等分布参数。结果显示,塔中47油藏中石炭系与志留系原油属同源;与油砂抽提物相比,包裹体烃类的成熟度较低;志留系油砂与包裹体烃类有不同的母源;志留系中至少存在两期油气充注,其晚期充注的油气有轻微水洗或生物降解作用。     

Observations of molecular clouds in nearby galaxies with ALMA

We present recent results of the observations of giant molecular clouds in nearby galaxies with the Nobeyama 45 m telescope and Millimeter Array. We give some brief comments about observations of GMCs in nearby galaxies with ALMA.     

鲫鱼(Carassius auratus)slc7A8基因分子特征及表达分析

采用RT-PCR和RACE技术克隆鲫鱼slc7A8基因的全长cDNA序列,对基因序列用生物软件对基因进行生物信息分析,用Real-time PCR方法检测基因在组织中的mRNA表达丰度。结果表明,鲫鱼slc7A8cDNA全长为2709bp,包含195bp的5′UCR序列,921bp的3′UCR序列,1593bp开放阅读框,编码530个氨基酸序列;鲫鱼与斑马鱼基因同源性和编码氨基酸同源性分别为88.9%和95.5%,而与其他动物分别在70.1%-74.8%和80.6%-82.1%之间;预测编码蛋白的分子量为57719.84,等电点为4.8,对其结构预测显示该蛋白具有与哺乳动物十分相似的12个螺旋跨膜结构,跨膜区氨基酸高度保守,不同动物间的同源性都在92.2%以上;Real-time PCR检测鲫鱼组织中的mRNA表达丰度高低顺序为前肠、中肠、脑、后肠、肌肉、肾、鳃、心、肝脏。     

Molecular systems in a strong magnetic field

Brief overview of one-two electron molecular systems made out of protons and/or α-particles in a strong magnetic field B≤4.414×10¹³ G is presented. A particular emphasis is given to the one-electron exotic ions H₃⁺⁺(pppe), He₂³⁺(α α e) and to two-electron ionsH₃⁺(pppee), He₂⁺⁺(α α ee). Quantitative studies in a strong magnetic field are very complicated technically. Novel approach to the few-electron Coulomb systems in magnetic field, which provides accurate results, based on variational calculus with physically relevant trial functions is briefly described.      

直至核幔边界的Mg2SiO4成分熔体剪切粘滞度的平衡分子动力学研究

熔体的粘滞度极大地影响熔体的各处动力学行为。虽然有一些有关酸碱生熔体粘滞度的数据但涉及地球更深部过程的基性和超基性熔体的粘滞度的数据很少。本项研究利用平衡分子动力学方法Ｍｇ２ＳｉＯ４成分熔体从２１６９Ｋ到５５９５Ｋ。压力从１０＾５Ｐａ到１３５ＧＰａ的粘滞度,所获得的粘滞度数据介于Ｕｒｂａｉｎｅｔ ａｌ,（１９８２）和Ｉｖａｎｏｖ ａｎｄ Ｓｔｅｎｇｅｌｍｅｙｅｒ（１９８２）的实验数据之间,比Ｓｈａ     

论泥晶套与次生白云岩原岩结构特征的恢复及意义

本文以偏光显微镜岩石薄片,扫描电镜,阴极发光等岩石学研究成果为基础资料,结合矿物学,岩石学,沉积学及物理化学基础理论,对白云岩中的残余结构,碳酸盐岩颗粒泥晶套的矿物成分,成岩变化及其在白云化等成岩作用过程中对颗粒结构及形态的保护作用进行了较为深入和系统的研究,认为泥晶套及其精细的鉴别对次生白云岩原岩结构特征及沉积环境的恢复既有重要的鉴定意义也是重要的研究方法,本文首先根据碳酸盐岩结构组分的类型,交代强度及可识别性把次生白云岩的残余结构分为交代残余结构,交代影像结构及交代晶粒结构三大类;每一大类还可根据具体的结构组分类型等进一步细分和命名。同时认为在研究次生白云岩残余结构（构造）的过程中,可通过寻找和鉴别受泥晶套保护的颗粒结构或轮廓,进而分析判别原始颗粒的结构和类型,达到恢复白云岩原岩（结构特征）的目的,在上述实际资料研究的基础上,又通过理论研究认为碳酸盐岩颗粒的泥晶套具有保护颗粒结构及形态免遭白云化作用等成岩作用彻底破坏的作用,这是因为泥晶套的原始矿物组成主要是文石,方解石及有机质等,且可在沉积期及成岩过程中吸附一定量的粘土矿物,泥晶套矿物晶体细小,特别是粘土矿物具有笼形结构,可以有选择地中附一定大小的分子（或离子）,结果使泥晶套具有分子筛（催化作用）,渗透膜的作用,既保护了颗粒免遭白云化作用等成岩作用的破坏,又加速了白云化作用等成岩作用的速度。     

南极磷虾(Euphausia superba)线粒体基因组特征及其分子标记应用

为揭示南极磷虾（Eupahusia superba）（甲壳动物：软甲纲：磷虾目）线粒体基因组特征,及通过比较不同海域南极磷虾的线粒体基因组探讨潜在的分子标记,采用Long PCR扩增技术获得采自普里兹湾（PrydzBay）南极磷虾线粒体基因组DNA,综合Primers-walking和Shotgun方法进行测序：通过生物信息学软件（DOGMA、tRNAscan-SE 1．21和DnaSP4．10．7等）进行基因预测及序列分析。南极磷虾线粒体基因组全长15498bp以上（部分非编码区未测定）,包含13个蛋白编码基因、2个核糖体RNA基因和23个转运RNA基因。与后生动物线粒体基因组标准的基因组成相比,存在1个trnN基因的重复。南极磷虾线粒体基因组的基因排列与泛甲壳动物线粒体基因组的原始排列相比,出现4个转运RNA基因的易位：trnL1、trnL2、trnW和trnl以及1个trnN的重复。比较采自普里兹湾（Prydz Bay）和威德尔海（Weddell Sea）南极磷虾的线粒体基因组,作者发现在南极磷虾线粒体基因组的主编码基因中,变异最大的是nad2基因,差异位点高达61个,其次是nad5基因,差异位点有12个：而coxl基因的变异位点仅有3个。Nad2基因和nad5基因可作为coxl基因辅助的分子标记,用于分析南极磷虾不同地理种群之间的遗传多样性,为合理利用南极磷虾生物资源提供保障。     

Jets and molecular outflows from Herbig-Haro objects

We review status of theoretical development for jets and molecular outflows from young stellar objects. A particular framework for explaining these phenomena is one based on the X-wind theory in an environment of magnetized collapsing molecular cloud cores. The magnetized gravitational collapse follows the standard picture of isolated low-mass star formation, from quasi-static evolution of the parent molecular cloud cores. The outflow phenomena operate throughout the early evolution of young stars as a result of star-disk interaction. We discuss emission mechanisms of jets and formation of molecular outflows in this general framework. The general theoretical framework provides room for self-consistent interpretations for recent observations. Jets and outflows are integral part of earliest evolution of young stellar objects.