赤道西太平洋部分海域上层水的海洋化学

主要研究了菲律宾东南海域（区域Ｉ）和伊里安岛东部的北部海域（区域Ⅱ）上层水（０～１５０ｍ）化学参数ｐＨ，Ｅｈ，Ｅｓ，∑Ｓ（－Ⅱ）和ａ＾２－ｓ等的分布特征和－２价硫的产生机制，结果表明，该海域表层南赤道逆流和次表层的赤道潜流是影响化学参数特别是ＤＯ和∑Ｓ（－Ⅱ）的主要因素，高生产力与高水温是赤道西太平洋上层水中－２价硫产生与保存的重要影响因素，区域Ⅱ中的ｐＨ，∑Ｓ（－Ⅱ）ａ＾２－ｓ，ＤＯ比区域Ｉ高而     

颗粒物质和微量金属在东海北部的沉积通量

于1990年运用沉积物捕捉器采样,实测了东海北部(32.00°N,126.00°E)海域颗粒物质和微量金属(Cu,Pb,Zn,Cr,Fe,Mn和Al)的海洋垂直通量。结果表明,颗粒物质的沉积通量随深度和季节而变化,明显地受上升流的影响。沉积的颗粒物质以0.45—63μm的小颗粒为主;Cu和Zn主要以有机物形式作垂直转移,Pb,Cr,Fe和Mn主要以弱键结合形式作垂直转移,Al则以硅酸盐的形式作垂直转移。沉积物中,颗粒Cu,Fe,Mn和Al以0.45—63μm的颗粒为主;颗粒Pb和Cr以大于63μm的颗粒为主;0.45—63μm和大于63μm的颗粒Zn在沉积物中占相近的比例。     

Dissolved inorganic carbon and CO2 fluxes across Jiaozhou Bay air-water interface

On the basis of data collected in the Jiaozhou Bay in June and July 2003, the DIC distribution in seawater is studied,and an average air-sea flux of CO2 is estimated. The results show that the content of DIC inside the bay is markedly higher than outside the bay in June, but the contem of DIC outside the bay is markedly higher than inside the bay in July. The trend of DIC distribution inside the bay is similar, viz. the content is the maximum in the northeast, then decreases gradually toward the west, and the content is the minimum in the west. The total trend of vertical distribution is to increase gradually from surface to bottom. This characteristic of DIC distribution is determined by Jiaozhou Bay hydrology and there is a close relation between DIC and particulate N.P. Average CO2 flux across the air-sea interface is 0.55 mol/(m^2.a) in June and 0.72 mol/(m^2.a) in July. Jiaozhou Bay is considered as a net annual source for atmospheric CO2 in June and July, and the total CO2 flux from seawater into atmosphere is about 740 t in June and 969 t in July.     

海洋沉积物中碳的来源、迁移和转化

人类活动每年向大气排放的CO2约为65亿t，其中留在大气中的约占50%，大洋吸收约16亿-20亿t，陆地生态系统大约吸收0.7亿~1.4亿t(Bates，2001；Battle et al.，2000),还有大约13亿t找不到去处，称为大气CO2丢失项，而陆架边缘海有可能是这丢失项的去处。近海沉积物是大气二氧化碳的接受者，同时当条件合适时沉积物中的碳又可被释放重新进入水体乃至大气中，是碳循环中的重要源与汇，因此海洋沉积物在碳循环中的作用是全球碳循环的一个关键环节。虽然近十年来这方面的研究已经引起众多学者的关注，对沉积物中的碳循环进行了较大量的研究，取得了一系列成果，但海洋沉积物在碳循环中的作用和过程至今并未查清，具体体现在海洋沉积物在海洋碳循环中起什么作用？起多大作用？在哪些方面影响和控制海洋碳循环？这些均需要科学家们长期的艰苦努力，以便在更深入、更系统和更高层次上研究解决困扰当今人类的涉及碳循环这一重大环境科学问题。 海洋沉积物为海洋环境中的一个主要研究对象，其中的碳与水体-生物体以及大气、入海河流等进行着不间断的交换、大气中的气体碳经过复杂的海洋生物地球化学过程转化为水体中的溶解碳，再变为颗粒碳，经沉降最终形成沉积物，在适宜的条件下上述的反过程同样会发生。因此，研究海洋沉积物中的碳在其循环中的作用是非常困难的。碳是最主要的生源要素，更是生命活动能流、物流中最重要的元素，几乎所有的生物地球化学循环过程都与它有关，因而有关碳循环的研究是目前全球变化研究的热点。许多国际研究计划均以此为核心研究内容。如国际地圈与生物圈计划(IGBP)中的全球海洋通量联合研究(JGOFS)、全球生态系统动力学(GLOBEC)以及上层海洋与低层大气研究计划(SOLAS)等(唐启升，2001；宋金明，2000)。碳循环研究以 JGOFS计划2001年基本结束为标志，通过近十几年的研究，取得了丰硕的成果，系统了解了海洋循环的过程及界面碳通量，对全球碳循环也有了一个初步的了解。为进一步深入开展这方面的研究作者从海洋沉积物中碳的形态与来源、海水及颗粒物中碳与沉积物碳的关系、表层沉积物再悬浮对碳循环的影响以及沉积物中碳的早期成岩作用等几个方面阐述了海洋沉积物中碳循环目前的研究进展。     

Spatial distribution and diurnal variation of chemical oxygen demand at the beginning of the rainy season in the Changjiang （Yangtze） River Estuary

A field observation was carried out in the Changjiang （Yangtze） River Estuary from May 19 to 26, 2003. A total of 29 stations, including 2 anchored stations, were occupied through almost the whole salinity gradient. Based on the observation data, biogeochemistry of chemical oxygen demand （COD） was examined. Spatial distribution pattern of COD shows that it decreased downstream. The COD concentration varied generally within a narrow range of 1.24-1.60 mg/L in the zone around the river mouth, beyond which it decreased rapidly to 0.20 mg/L. In the mixed water zone, the fluctuation in COD was smaller at 2 m above the bottom layer than at the surface layer in 48 h. In the seawater zone, the 48-h fluctuation at the surface was the largest, followed by that of 5 m below the surface and 2 m above the bottom layers in a range of from 2.50 to 0.55 mg/L. Freshwater discharge was the dominant source of COD in the estuary. The average COD beyond the river mouth was 2.7 mg/L, which accorded with the Chinese seawater quality Grade I. Relationships between dissolved oxygen and biogeochemical parameters such as suspended particulate matter, dissolved organic matter and chlorophyll-a were also discussed.     

基于磷脂脂肪酸的热带西太平洋沉积物生源要素矿化过程探析

甄别生源要素参与的海洋沉积物矿化过程对探析生源要素的生物地球化学循环有重要的作用,矿化作用包括有氧呼吸、硝酸盐还原、铁锰异化还原及硫酸盐还原等多个过程,但如何区分这些过程一直是海洋沉积物矿化研究的难点。本研究采用气相色谱-质谱(GC-MS)联用对热带西太平洋沉积物中的磷脂脂肪酸(phospholipid fatty acid, PLFA)的组成进行了解析,并分析不同矿化过程中的主要PLFA种类及其影响因素,探究PLFA对沉积物矿化的指示作用。结果表明,PLFA总量在有氧呼吸过程中最高,而在硝酸盐还原过程中最低;且14:0、i14:0、i15:0和i19:0是有氧呼吸过程中微生物PLFA的主要组成,当其含量明显降低时可以指示沉积物矿化从有氧呼吸转变为硝酸盐还原;而10:0、17:0、20:0和22:0含量之和显著增加时则指示了硫酸盐还原过程的发生。在热带西太平洋沉积物中,总有机碳(TOC)和总有机氮(TON)含量以及间隙水NO₃-N含量是PLFA含量的重要影响因素,PLFA总量随着TOC和TON含量的减少而减少,并且TOC和TON的降解能够促进PLFA降解的发生,对PLFA组成有更直接的影响。     

An Early Paleozoic Ultramafic Complex in the North Wulan Metamorphic Complex,North Qaidam:Contraints on the Nature of the Alaskan-type Continental Arc Root

Orogenic peridotite is an important component of orogenic belts and retains crucial information on mantle magmatic activity, slab subduction, and melt or fluid metasomatism. To determine the source of the mantle-derived parental magma of the peridotite and to investigate the metasomatism that it experienced, we undertook an integrated study of the petrography, whole-rock major-and trace-element compositions, in situ zircon U-Pb geochronology, and mineral majorand trace-element compositions of an...     

CO2 flux and seasonal variability in the turbidity maximum zone and surrounding area in the Changjiang River estuary

The turbidity maximum zone(TMZ) is one of the most important regions in an estuary.However,the high concentration of suspended material makes it difficult to measure the partial pressure of CO_2(pCO_2) in these regions.Therefore,very little data is available on the pCO_2 levels in TMZs.To relatively accurately evaluate the CO_2 flux in an example estuary,we studied the TMZ and surrounding area in the Changjiang(Yangtze) River estuary.From seasonal cruises during February,August,November 2010,and May 2012,the pCO_2 in the TMZ and surrounding area was calculated from pH and total alkalinity(TA)measured in situ,from which the CO_2 flux was calculated.Overall,the TMZ and surrounding area acted as a source of atmosphere CO_2 in February and November,and as a sink in May and August.The average FCO_2was-9,-16,5,and 5 mmol/(m~2·d) in May,August,November,and February,respectively.The TMZ's role as a source or sink of atmosphere CO_2 was quite different to the outer estuary.In the TMZ and surrounding area,suspended matter,phytoplankton,and pH were the main factors controlling the FCO_2,but here the influence of temperature,salinity,and total alkalinity on the FCO_2 was weak.Organic carbon decomposition in suspended matter was the main reason for the region acting as a CO_2 source in winter,and phytoplankton production was the main reason the region was a CO_2 sink in summer.     

基于DSP的GNSS实时高频姿态测量技术研究

本文研究了基于DSP的GNSS实时高频姿态测量技术。针对实时高频应用中遇到的计算时间无法满足高频需求的问题,仔细分析了时间消耗的主要特点。利用姿态测量中单历元固定双差模糊度成功率高的特点,提出一种继承模式的模糊度处理方案。该方案在没有发生周跳或者没有发生卫星升起降落的情况下,不计算模糊度参数,直接使用前一历元的模糊度,避开了模糊度的计算,大幅度的降低了计算时间。实验证明:在同一款DSP下,提出的方法能够有效的解算姿态参数,计算时间削减了33%,计算结果没有精度损失。     

PCBs and its coupling with eco-environments in Southern Yellow Sea surface sediments

In this paper, the spatial distribution and source of the PCBs in surface sediments of the Southern Yellow Sea (SYS) and influencing factors, such as the sediment characteristics (components, relative proportions and total organic carbon contents), and hydrodynamic conditions were analyzed. PCB concentrations in the surface sediments ranged from 518-5848 pg/g, with average values of 1715 pg/g decreasing sharply compared to last year. In the study area, the PCB pollution level in the middle area was the highest, followed by that of the east coast and the west coast, respectively. Although the PCB level in the coastal areas was lower than that in the middle areas, it was proven in our study that the Yellow Sea obtained PCBs by virtue of river inputs. There was a positive and pertinent correlation between the clay proportion and PCB concentrations, and the increase of the PCB concentrations was directly proportional to the increase of TOC contents, with r=0.61, but it was contrary to the sediment grain size. Consequently, the factors controlling PCB distribution had direct or indirect relationships with sediment grain size; moreover, the hydrodynamic conditions determined the sediment components and grain size. In conclusion, hydrodynamic conditions of the Yellow Sea were the most important influencing factors effecting the distribution of PCBs in the surface sediments of the SYS.