DNA barcode assessment of Ceramiales (Rhodophyta) in the intertidal zone of the northwestern Yellow Sea

A total of 142 specimens of Ceramiales(Rhodophyta) were collected each month from October 2011 to November 2012 in the intertidal zone of the northwestern Yellow Sea. These specimens covered 21 species,14 genera,and four families. Cluster analyses show that the specimens had a high diversity for the three DNA markers,namely,partial large subunit r RNA gene(LSU),universal plastid amplicon(UPA),and partial mitochondrial cytochrome c oxidase subunit I gene(COI). No intraspecific divergence was found in our collection for these markers,except for a 1–3 bp divergence in the COI of Ceramium kondoi,Symphyocladia latiuscula,and Neosiphonia japonica. Because short DNA markers were used,the phylogenetic relationships of higher taxonomic levels were hard to evaluate with poor branch support. More than half species of our collection failed to find their matched sequences owing to shortage information of DNA barcodes for macroalgae in Gen Bank or BOLD(Barcode of Life Data) Systems. Three specimens were presumed as H eterosiphonia crispella by cluster analyses on DNA barcodes assisted by morphological identification,which was the first record in the investigated area,implying that it might be a cryptic or invasive species in the coastal area of northwestern Yellow Sea. In the neighbor-joining trees of all three DNA markers,H eterosiphonia japonica converged with D asya spp. and was distant from the other Heterosiphonia spp.,implying that H. japonica had affinities to the genus Dasya. The LSU and UPA markers amplified and sequenced easier than the COI marker across the Ceramiales species,but the COI had a higher ability to discriminate between species.     

基于GIS的零售商业网点选址评价模型研究

传统零售商业网点选址模型主要是基于统计的静态模型.分析了影响零售商业网点选址的人口、经济、市场竞争三个关键要素,结合GIS,提出了一种基于权重设置的零售商业网点选址评价模型,并阐述了模型的应用流程.该模型在深圳市罗湖区公共信息服务平台中进行了典型应用实现,并检验了模型的应用可行性.     

流式影像术在海洋浮游植物分类研究中的应用

海洋浮游植物支撑着海洋生态系统的正常运转,对其种类的定性识别、鉴定和细胞数量的定量分析是海洋科学研究中最为关键的科学问题之一。流式影像术在海洋浮游植物形态特征识别与快速定量检测上是目前先进和可行的方法,它综合了流式细胞术和图像显微识别的技术优点,不但能够对快速流动状态中的海洋浮游植物进行相应的参数检测,而且可以获取流动过程中清晰的图像,通过计算机软件的图像处理和特征筛选,实现海洋浮游植物有效的自动识别。通过对流式影像术的原理、测定方法、技术特点及其发展动态等的综述,认为基于流式影像术对高速运动的浮游植物图像的清晰实时采集,可以有效地对图像进行模式的识别和分类。它是一种理想和实用的方法,将为海洋生物学研究提供新的实时、快速、高效平台,有很好的应用前景。     

埋藏第四系的沉积相研究——地球物理测井解释在第四纪沉积研究中的应用

关于第四纪埋藏沉积物成因类型的研究,常规的方法是利用钻井取芯资料进行综合分析和对比,所得结论往往是定性的。由于钻井取芯的费用十分昂贵,且第四纪松散沉积物的收获率一般比较低,所以这种方法的广泛应用受到了很大的限制。本文介绍了一种利用测井资料进行沉积相分析的思路和方法。由于地球物理测井具有快速、经济等特点,因此该方法在第四纪沉积的研究中具有较好的应用前景。另外,随着计算机的广泛使用,人工智能技术的迅速发展为测井相分析的定量化和自动化提供了实现的途径。     

Estimates of AGN Black Hole Mass and Minimum Variability Timescale

Black hole mass is one of the fundamental physical parameters of active galactic nuclei (AGNs), for which many methods of estimation have been proposed. One set of methods assumes that the broad-line region (BLR) is gravitationally bound by the central black hole potential, so the black hole mass can be estimated from the orbital radius and the Doppler velocity. Another set of methods assumes the observed variability timescale is determined by the orbital timescale near the innermost stable orbit around the Schwarzschild black hole or the Kerr black hole, or by the characteristic timescale of the accretion disk. We collect a sample of 21 AGNs, for which the minimum variability timescales have been obtained and their black hole masses (Mσ) have been well estimated from the stellar velocity dispersion or the BLR size-luminosity relation. Using the minimum variability timescales we estimated the black hole masses for 21 objects by the three different methods, the results are denoted by Ms, Mk and Md, respectively. We compared each of them with Mσindividually and found that: (1) using the minimum variability timescale with the Kerr black hole theory leads to small differences between Mσand Mk, none exceeding one order of magnitude, and the mean difference between them is about 0.53 dex; (2) using the minimum variability timescale with the Schwarzschild black hole theory leads to somewhat larger difference between Mσand Ms: larger than one order of magnitude for 6 of the 21 sources, and the mean difference is 0.74 dex; (3) using the minimum variability timescale with the accretion disk theory leads to much larger differences between Mσand Md, for 13 of the 21 sources the differences are larger than two orders of magnitude; and the mean difference is as high as about 2.01 dex.     

二安替比林基—（2—溴）苯基甲烷与铈的显色反应及应用

合成了二安替比林基＿（２＿溴）苯基甲烷（ＤＡｏＢＭ）。在Ｍｎ（Ⅱ）和吐温＿８０存在下,Ｃｅ（Ⅳ）与ＤＡｏＢＭ反应生成有色化合物,λｍａｘ为４８０ｎｍ,摩尔吸光系数为３１×１０５Ｌ·ｍｏｌ－１·ｃｍ－１。Ｃｅ（Ⅳ）的质量浓度为０００４～０２ｍｇ／Ｌ时符合比尔定律。方法已用于稀土矿石中微量Ｃｅ（Ⅳ）的测定,结果与ＩＣＰ＿ＡＥＳ法相符     

利用量子力学势能数据预测温度、压力、盐度和沉积物孔径对甲烷水合物形成和分解的影响

介绍一个预测不同温度、压力、盐度和沉积物毛细管孔径条件下甲烷水合物 溶液 气体多相平衡模型。该模型以Van der Waals和 Platteeuw热力学模型、量子力学从头算粒子相互作用势能、DMW 92状态方程和Pitzer电解质理论为基础,能在很宽广温压范围内预测温度、压力、盐度和毛细管力对甲烷水合物形成和分解的影响。通过对比本模型的预测结果与实验数据,可知本模型能够准确地预测海水和多孔介质中甲烷水合物的相平衡条件。对于一定盐度下多孔介质中甲烷水合物的形成温压条件的在线计算可浏览: www.geochem model.org/models.htm。     

基于空间变异修正普通克里金的矿区复杂地形高精度建模

普通克里金法是构建矿区三维地形模型并揭示地表沉陷形变场动态变化规律的有效方法。但普通克里金法存在平滑效应的问题,导致估计值的空间变异程度小于实际,无法真实反映矿区复杂地表形态的空间变化特征。本文结合矿区实际地形采样数据,提出了一种空间变异修正的普通克里金法,并将其应用于矿区复杂地形的高精度建模,并与已有方法在建模精度和空间变异性复现方面进行了对比分析。研究结果表明,空间变异修正的普通克里金法能够很好地处理平滑效应对建模的影响,具有更高的建模精度和空间变异性复现能力,在矿区复杂地形高精度建模应用中具有较强的适用性,可以作为一种可靠的建模工具用于矿区复杂地形沉陷形变场动态变化规律分析。     

用脉冲磁场方法研究现代沉积物中趋磁细菌的趋磁性和趋化性

光学显微镜下直观显示水体环境中趋磁细菌沿磁场方向定向排列和游动,人们对其认识主要来自这些镜下观察的总结。但实际上趋磁细菌主要生活在沉积物环境中,很难对它们进行直接观察。因此,趋磁细菌在沉积物环境中的趋磁性、趋化性、以及在记录古地磁过程中可能起到的作用等方面均尚未得到足够实际观测数据的支持。本研究利用脉冲磁场反转趋磁细菌(Candidatus Magnetobacterium bavaricum)极性的特性,将趋北趋磁细菌(NS)转变为趋南趋磁细菌(SS),并在只含有NS的沉积物中以脉冲磁场反转的SS为"示踪体",分析趋磁细菌在沉积物环境中的趋磁性和趋化性。使沉积物所处的外界磁场与脉冲磁场方向保持一系列角度Φ(0°~180°),利用施加脉冲磁场后出现的SS%与Φ关系估算趋磁细菌在沉积物中沿外界磁场的排列程度,证实了趋磁细菌在沉积物中沿地磁场排列程度非常低(<1%)。将脉冲SS分别置于4种不同的磁场条件(磁场方向指向上、指向下和水平)和生存环境(上部适宜环境和下部不适宜环境),一定时间后SS的垂直分布相对直观地证实了:趋磁细菌游动方向受趋化性决定,趋磁性的优势在于使趋磁细菌更有效地到达其最佳生存环境。脉冲磁场方法在理解和研究沉积物中趋磁细菌趋磁性、趋化性和古地磁应用方面有可观的应用前景。     

Masses for free-floating planets and dwarf planets

The mass and distance functions of free-floating planets(FFPs) would give major insights into the formation and evolution of planetary systems, including any systematic differences between those in the disk and bulge. We show that the only way to measure the mass and distance of individual FFPs over a broad range of distances is to observe them simultaneously from two observatories separated by D ～ O(0.01 au)(to measure their microlens parallax π_E) and to focus on the finite-source point-lens(FSPL) events(which yield the Einstein radius θ_E). By combining the existing KMTNet 3-telescope observatory with a 0.3 m 4 deg~2 telescope at L2, of order 130 such measurements could be made over four years, down to about M ～ 6 M_⊕for bulge FFPs and M ～ 0.7 M_⊕for disk FFPs. The same experiment would return masses and distances for many bound planetary systems. A more ambitious experiment, with two 0.5 m satellites(one at L2 and the other nearer Earth) and similar camera layout but in the infrared, could measure masses and distances of sub-Moon mass objects, and thereby probe(and distinguish between) genuine sub-Moon FFPs and sub-Moon "dwarf planets" in exo-Kuiper Belts and exo-Oort Clouds.