Interactions between thorium, protactinium and particles and applications in tracking the cycling of biogenic particles

颗粒物组分对Th和Pa同位素的分馏是影响231Pa/230Th和234Th/238U等作为海洋颗粒动力学指标的关键因素，亦是当前同位素海洋学研究的焦点问题之一。论文通过实验室模拟研究了21种无机及有机颗粒物对234Th和233Pa的吸附作用以及分馏效应，并进行了无机-有机颗粒物协同作用下Th和Pa同位素的吸附行为研究。同时，在热带太平洋、印度洋中部及西南部海域、南大洋印度洋扇区、南海以及台湾海峡等海域进一步探究了颗粒物中生源组分POC和BSi在234Th清除和输出过程中的作用。得到以下主要研究结果： （1）纯颗粒物组分对Th和Pa的吸附作用：化学组成不同或化学组成相同但结构不同的颗粒物对Th...Fractionation between thorium and protactinium during scavenging in the ocean has challenged the 231Pa/230Th and 234Th/238U ratios as oceanographic proxies of particle dynamics in the past years. In this study, the adsorption of 234Th and 233Pa onto 21 types of inorganic and organic particles were examined in the laboratory simulation experiments as well as the fractionation effects. The influence...学位：理学硕士院系专业：海洋与环境学院海洋学系_海洋化学学号：2242009115113

绩效预算改革探析

绩效预算是一种以目标为导向, 以项目成本为衡量标准,以业绩评价为核心的一种预算管理方法。绩效预算的提出,对于建立财政支出“追踪问效”的管理机制,提高预算分配决策水平,优化财政支出结构,降低政府运行成本,促进收支矛盾的缓解,以及“重收轻支粗管理”现象的改观,从而形

公益性·垄断性·收费性·竞争性———论公共基础设施投资多元化

公共基础设施投资具有公益性、垄断性、收费性和竞争性的特点。公益性和垄断性决定了公共基础设施建设投资的“非市场性”;收费性和竞争性又决定了其投资的“市场性”。公共基础设施投资多元化问题 ,就是如何正确处理公共投资与私人投资的配合问题。公共基础设施领域的改革是我国经济体制进一步改革的突破口。为此 ,提出如下建议:进行相应的制度改革;注意改革的循序渐进;建立以收费为主的成本补偿机制;实行与投资多元化相配套的多样化的经营方式

Export Fluxes of POC and Biogenic Silica in the Kuroshio by Means of ~(234)Th/~(238)U Disequilibria

对东海陆架外黑潮区颗粒有机碳(POC)和生物硅(bSIO2)的研究表明:台湾东北部黑潮主流真光层(100 M)POC和bSIO2的平均浓度分别为3.31μMOl/l和0.68μMOl/l;234TH/238u不平衡法获得POC和bSIO2的输出通量分别为3.7 MMOl/(M2·d)和1.6 MMOl/(M2·d).黑潮沿东海陆架北进过程中,POC和bSIO2的含量及输出通量均呈增加趋势.位于日本西南的黑潮主流中,POC和bSIO2的平均浓度分别为3.85μMOl/l和2.63μMOl/l,输出通量分别为6.7 MMOl/(M2·d)和4.0 MMOl/(M2·d).黑潮与陆架水形成的锋面区,POC和bSIO2浓度均高于黑潮主流.To reveal the primary characteristics of the POC and biogenic silica( bSiO2) in the Kuroshio,as well as their export from the euphotic zone,POC,bSiO2 and234Th were examined.The average concentrations of POC and bSiO2 were 3.31 μmol / L and 0.68 μmol / L in the main Kuroshio stream to northeast Taiwan respectively,corresponding to their respective export fluxes of 3.7 mmol /( m2·d) and1.6 mmol /( m2·d).Along the flow of Kuroshio northwards,the concentrations of both POC and bSiO2 increased to a varying degree.To southwest Japan,the contents of POC and bSiO2increased up to3.85 μmol / L and 2.63 μmol / L respectively.The export fluxes of POC increased to 6.7 mmol /( m2·d),accompanying the bSiO2flux of 4.0 mmol /( m2·d).The average concentrations of POC and bSiO2 in the Kuroshio frontal zone were higher than the values in the main stream.中国大洋协会课题资助项目;编号DY125-13-E-01; 国家自然科学基金资助项目;编号41076043;4112502

Biological N_2 fixation rates in the East China Sea in spring 2009

2009年4~5月间,应用15n2示踪法实测了东海25个站位的生物固氮速率,结合温度、盐度等要素的分布,分析生物固氮速率的空间变化及其影响因素.结果表明,春季东海的生物固氮速率介于102~16 349 nMOl/(M3·d)之间,平均为2 441 nMOl/(M3·d).生物固氮速率的空间变化呈现径流影响区最高,黑潮影响区与陆架其他区域相近的特点,径流影响区的平均生物固氮速率约为黑潮影响区和陆架其他区域的2倍,这可能与固氮生物种类的空间变化有关.春季东海的积分固氮速率平均为129μMOl/(M2·d),结合此前获得的夏、秋、冬季的积分固氮速率,估算出东海生物固氮速率的年均值为50μMOl/(M2·d),因而东海的年固氮通量估计为1.4x1010MOl/A,约占全球海洋年固氮通量的0.15%.对东海进行的氮源汇分析表明,生物固氮作用、长江径流输入和大气沉降输入等氮输入通量分别为1.4x1010、7.9x1010和3.9x1010MOl/A,反硝化作用和沉积物颗粒氮埋藏的迁出通量分别为9.5x1010和3.7x1010MOl/A,东海氮的源汇通量均为13.2x1010MOl/A,表明东海氮的收支基本处于平衡状态.Biological N2fixation rates at 26 stations in the East China Sea were measured with15N2tracer assay during April and May 2009.Combined with temperature and salinity,the distribution of N2fixation rates and their influencing factors were discussed.Our results showed that the N2fixation rates ranged from 102 to 16 349 nmol/(m3·d) with an average of 2 441 nmol/(m3·d).The highest rates were observed in regions influenced by the river plume,which was about two times what observed in regions influenced by the Kuroshio current and the shelf waters,probably reflecting the spatial variation of the nitrogen fixers.The integrated N2fixation rate in the East China Sea in spring was129 μmol/(m2·d) in average,and the annual N2fixation rate was estimated as 50 μmol/(m2·d) compared with previous data in summer,autumn and winter.This meant that the new nitrogen flux supply by N2fixation to the East China Sea was 1.4×1010mol/a,contributing to about 0.15% of the N2fixation flux in global oceans.The nitrogen budget in the East China Sea was evaluated in views of sources and sinks.The fluxes of nitrogen supply to the East China Sea via the nitrogen fixation,the river runoff and the atmospheric deposition were estimated as 1.4×1010,7.9 ×1010and 3.9×1010mol/a,respectively.The removal fluxes of nitrogen via denitrification and sedimentary burial were 9.5×1010and 3.7×1010mol/a,respectively.Both the nitrogen flux of the sources and the sinks were 13.2×1010mol/a,indicating a balance of nitrogen budget in the East China Sea.国家自然科学基金杰出青年基金资助项目(41125020); 国家海洋局大洋专项资助项目(DY125-13-E-01