福建南部沿海的江豚

在闽南厦门至漳浦沿海获22只江豚,根据背部棘状小结节的数量与分布,可明显分为两个亚种,即指名亚种(N.P.Phocaenoides,81%)和北方亚种(N.P.Sunameri,19%),表明本海域是几个亚种的混栖地带,分析了这些江豚的外部形态和种群结构,测定了脂肪层及各内脏的重量.     

The chemical changes of DOM from black waters to coastal marine waters by HPLC combined with ultrahigh resolution mass spectrometry

How dissolved organic matter (DOM) undergoes chemical changes during its transit from river to ocean remains a challenge due to its complex structure. In this study, DOM along a river transect from black waters to marine waters is characterized using an offline combination of reversed-phase high performance liquid chromatography (RP-HPLC) coupled to electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS), as well as tandem ESI-FTICR-MS. In addition, a water extract from degraded wood that mainly consists of lignins is used for comparison to the DOM from this transect. The HPLC chromatograms of all DOM samples and the wood extract show two major well-separated components; one is hydrophilic and the other is hydrophobic, based on their elution order from the C₁₈ column. From the FTICR-MS analysis of the HPLC fractions, the hydrophilic components mainly contain low molecular weight compounds (less than 400 Da), while the hydrophobic fractions contain the vast majority of compounds of the bulk C₁₈ extracted DOM. The wood extract and the DOM samples from the transect of black waters to coastal marine waters show strikingly similar HPLC chromatograms, and the FTICR-MS analysis further indicates that a large fraction of molecular formulas from these samples are the same, existing as lignin-like compounds. Tandem mass spectrometry experiments show that several representative molecules from the lignin-like compounds have similar functional group losses and fragmentation patterns, consistent with modified lignin structural entities in the wood extract and these DOM samples. Taken together, these data suggest that lignin-derived compounds may survive the transit from the river to the coastal ocean and can accumulate there because of their refractory nature.     

南极纳尔逊冰帽的雪层及其成冰作用研究

纳尔逊冰帽雪—粒雪的演化依赖于融水渗浸冻结作用下的暖变质过程。积雪的密实化过程的快慢,取决于温度条件和融水的参与程度,以及自身的物理状况。粒雪的密实化过程表现为均匀且变幅小。纳尔逊冰帽成冰深度在23～25m,成冰历时17～19年。成冰带分为暖渗浸—重结晶带,渗浸—冻结带,消融带。     

巴基斯坦城镇体系特征及其影响因素

基于人口普查数据、自然环境、经济产业及交通路网等公开数据,运用城镇体系金字塔、城镇规模基尼系数以及核密度分析等方法,对巴基斯坦城镇体系特征及其影响因素进行分析,发现:1)规模结构方面,城镇规模分布较集中,表现为"大城市化"与"小城市化"并重的特征,中间级别城市发展滞后,城镇人口金字塔大致呈现沙漏形态;空间结构方面,整体...     

高精度重力测量在岩溶地区的初步应用

<正> 一、概 况 在山东省泰安县潘河桥头Ⅳ号工区,解决岩溶地区坍陷问题中,试验研究采用大比例尺高精度重力测量,取得一定效果。 工区内灰岩埋深一般在25米左右,其上为第四系复盖,地形平坦,第四系的密度为1.9～2.0克/厘米~3,灰岩的密度为2.5～2.7克/厘米~3,上部为鲡状灰岩,溶蚀现象十分明显,岩溶发育,溶洞直径小的有几厘米,大的有几米,但最大直径没有超过10米。鲡状灰岩下部为豹皮灰岩,结构致密,也有小的溶洞存在。溶洞中多数充填砂粒、粘土等第四系沉积物。     

Quantitative evaluation of weathering degree through Fuzzy-AHP method and petrophysics analysis for sandstone carvings

Natural Hazards - The assessment of weathering degree of sandstone carvings plays an important role in scientific conservation. However, the current state of weathering assessment research cannot...     

放射性测量技术在油气勘查中的应用

本文介绍的油气勘查中的放射性测量，是一种油气普查新方法。它是利用油田上出现的负异常（或叫偏低场），反映了油气田的大体轮廓的基本原理进行的。前人及作者都取得了一定的工作成果。虽然取得了初步效果，但对机理等问题仍需进一步研究和完善。     

蚀变岩中物质迁移的定量计算：以锡矿山锑矿床为例

本文提出了确定沉积岩蚀变作用过程中的不活动组分的方法，并以锡矿山锑矿床为例，定量计算了蚀变岩中各组分的带入带出量，研究表明：锡矿山锑矿硅化过程中ＴｉＯ２和Ａｌ２Ｏ３为不活动组；ＳｉＯ２，Ｋ２Ｏ，Ｎａ２Ｏ及锑，硫，坤，汞，铅和钡为带入组分；而ＣａＯ，ＭｇＯ，Ｆｅ２Ｏ３，ＭｎＯ及铜，锌为带出组分，锑，钡，硫，ＳｉＯ２和ＣａＯ有较大的带进或带出量，锡矿山锑矿床矿石矿物为单一辉锑矿可能是由于矿液中缺少其它     

华北板块和塔里木板块之关系

华北板块和塔里木板块在中国大陆岩石圈的形成和演化中占有突出地位，关于它们的界线和关系的，长期以来是含糊不清的。本文提出在内蒙古阿拉善北部，新近发现的恩格尔乌苏蛇绿混杂带是华北板块和塔里木板块的缝合带，蛇绿混杂带主要由源自古大洋壳的岩石碎块及活动与被动大陆边缘的沉岩混合组成，可区分为构造包体和基质。缝合带向东北延伸到蒙古镜内，向西可能与阿尔金大断裂相连。以恩格尔乌苏蛇绿混杂带为界，阿拉善南北两分别属     

Effects of key components of <Emphasis Type="Italic">S. triqueter</Emphasis> root exudates on fractions and bioavailability of pyrene–lead co-contaminated soils

The key components of S. triqueter root exudates involved 4-oxo-pentanoic acid, succinic acid, glutaric acid, phthalate acid, citric acid, vanillic acid, myristic acid, pentadecanoic acid, decanoic acid, 14-methyl-pentadecanoic acid, hexadecanoic acid, octadecanoic acid and oleic acid, and the content of the water-soluble organic acids (citric acid, succinic acid and glutaric acid) significantly increased in pyrene and lead co-contaminated rhizosphere soil. These three water-soluble organic acids including citric acid, succinic acid and glutaric acid were detected as the specific root exudates of S. triqueter under stress of pollutants for pyrene and lead, so they were chosen as the research objects, and they were added into the bioremediation systems of pyrene and lead co-contaminated wetland soils. Compared with the control, the treatments added the three organic acids always improved the quantity of the bioavailable fraction of pyrene and lead in wetland soils and greatly influenced other chemical states of pyrene and lead fractions in the test concentration range. Under the 50 g kg^?1 of organic acids concentration, the amount of the bioavailable fraction of pyrene and lead increased 41.0 and 872.7 % by citric acid, respectively. The enhancement of bioavailability of pyrene and lead in the wetland soil by adding organic acids generally decreased in the following order: citric acid > succinic acid > glutaric acid. Enhancing effects of organic acids on the bioavailability improvement of pyrene and lead is remarkable.