Marine Biogeochemistry of 210Po and 210Pb and Their Implications Regarding the Cycling and Export of Particles

本研究系统、深入地研究了五个具有典型特征海区（南极普里兹湾及其邻近海域、寡营养盐低叶绿素（LNLC）的南沙海域、南沙群岛珊瑚礁生态系、厦门湾和九龙江河口区）210Po和210Pb的生物地球化学行为，并在此基础上应用210Po/210Pb不平衡示踪了颗粒物及相关生源要素的循环与输出。该论文主要研究结果如下：1.不同营养状况大洋水中210Po、210Pb的地化行为：表层大洋水体中210Po、210Pb主要以溶解态形式存在，但不同营养状况的大洋环境中，210Po、210Pb的地球化学行为存在比较明显的差异。微生物和颗粒物是影响210Po地化行为的两个主要因素。在寡营养的南沙海域，由于生源颗粒相对贫乏...Biogeochemical cycle of dissolved and particulate 210Po and 210Pb, along with their disequilibria in five typical sea areas, i.e. the Prydz Bay and its adjacent waters, the Southern South China Sea with low nutrients and low chlorophyll-a (LNLC), the Zhubi coral reef lagoon, the Xiamen Bay and the Jiulong River estuary, and their applications in the cycling and export of particulate matter related...学位：理学博士院系专业：海洋与环境学院海洋学系_海洋化学学号：B20022700

Investigation of transparent Al-doped ZnO films for high performance GaN-based light emitting diodes

多晶的或无定形的透明导电氧化物(Transparentconductingoxides，简称TCOs)，由于其独特的光学和电学性能，成为近年来研究的热点。其中，铝掺杂氧化锌（Al-dopedZnO,简称AZO）因具有低电阻率和高可见光区透过率，成为主要的透明导电氧化物材料之一，加上其原材料丰富，价格低廉且无污染，在光电器件领域有望替代ITO成为最理想的透明导电材料。本文采用射频磁控溅射技术首次在室温下，以ZnO:Al2O3(98：2wt%)为靶材，在石英玻璃衬底上制备多晶AZO透明导电薄膜。同时应用X射线衍射仪（XRD）、原子力显微镜（AFM）、扫面电子显微镜（SEM）、俄歇电子能谱仪（AES...Recently, a great deal of interest has been fueled in the development of polycrystalline or amorphous transparent conducting oxide (TCO) semiconductors used for practical thin-film transparent electrode applications, due to their excellent electrical and optical properties. Aluminum-doped zinc oxide (AZO) thin films, which are the most important TCO, with low resistivity and high transparency in v...学位：理学博士院系专业：物理与机电工程学院物理学系_凝聚态物理学号：1812005140302

中国近海生态环境变化的同位素示踪研究

同位素在确定物质来源、指示生物地球化学循环路径、定量生物地球化学过程速率等方面具有独特的优势,本文以近海生态环境变化研究中常用的稳定同位素(13C、15N、18O)和放射性核素(14C、234Th、232Th、230Th、228Th、210Po、210Pb、137Cs、226Ra、228Ra、224Ra、223Ra)为对象,介绍它们在揭示海洋有机质来源、食物网结构、水体缺氧机制、氮循环过程、颗粒动力学、海底地下水输入、有机地球化学过程、沉积年代学等方面的应用,侧重于总结我国近海生态环境研究中同位素示踪取得的进展。伴随着我国经济的发展,近百年来我国近海生态环境也发生了明显的变化,基于同位素示踪揭示的近海富营养化和沉积环境的演变规律表明,我国近海生态环境自20世纪50年代起经历持续的变化,特别是在过去2030年时间里,近海生态环境的变化尤为剧烈,反映出人类活动是我国近海生态环境变化的主要驱动力。未来需要通过发展新的同位素技术及拓展更广泛的应用,围绕近海海洋生态环境变化的突出问题,重点揭示近海生态环境变化的响应特征、变化速率和作用机制,从而系统地掌握近海生态环境的时空变化规律。国家重点基础研究计划课题(2015CB452903,2015CB452902);;国家海洋公益性行业科研专项(201505034

Somatotype study of the Tunguska living in China

体型是对身体形状和组成成分的描述,影响人的生理机能、运动素质、心理情感、职业选择等多方面,可帮助评价个体生长发育状况并指导健康成长,因而具有重要; 的实际意义。通古斯族群的起源、迁移及各民族之间亲缘关系问题历来为学者所关注和争论。本研究在辽宁、黑龙江、和内蒙古自治区随机抽取辽宁满族、黑龙江满; 族、鄂伦春族、鄂温克族、赫哲族成人人群(男女皆有)进行Heath-Carter法体型研究,探讨中国境内通古斯人群的体型特点及规律,为分析中国境内; 通古斯人群的亲缘关系提供体质人类学方面的证据。Somatotype analysis involves the description about body shape and; composition, which can affect, for example, physical function, sport; capabilities, mental emotions, and career choice. Additionally; somatotype can help in evaluating an individual's growth and; development, leading them to healthy growth. There have always been; debates about the origin, migration, and kinship of the Tunguska. This; paper uses the Heath-Carter somatotype method for the Liaoning Manchu,; Heilongjiang Manchu, Oroqen, Ewenki, and Hezhen adults (both males and; females) who were chosen randomly from the autonomous regions of; Liaoning, Heilongjiang and Inner Mongolia. This study discusses these; somatotype characteristics of the Tunguska and analyzes the kinship of; this group in China

Distribution of radionuclides at surface sediments in Chukchi Shelf

对中国首次北极科学考察期间在楚科奇海采集的9个表层沉积物样品进行了γ谱分析。结果表明,2 1 0 Pb的比活度介于16.0～76.6Bq·kg 1 之间,平均为3 6.9Bq·kg 1 ,低于大多数中低纬度区表层沉积物的2 1 0 Pb比活度,反映出研究海域低的大气2 1 0 Pb输入通量。2 2 6 Ra、1 37Cs、2 38U的放射性比活度范围和平均值分别为11.4～2 0 .9、1.7～2 .9、3 2 .4～5 3 .4Bq·kg 1 和17.6、2 .2、44 .4Bq·kg 1 。研究海域表层沉积物中的2 2 6 Ra/2 38U ) A .R .介于0 .3 5～0 .47之间,低的2 2 6 Ra/2 38U) A .R .表明U、Ra的地球化学行为存在差异。2 1 0 Pb、2 1 0 Pbex、1 37Cs、4 0 K比活度和灼烧失重率均随离岸距离的增加逐渐减小,而2 2 6 Ra和2 38U则具有各自不同的分布特征,分别与研究海域表层沉积物Si和Ca的分布比较类似。对核素间相关关系的分析表明,研究海域表层沉积物中1 37Cs和2 1 0 Pbex含量与灼烧失重率之间存在良好的线性正相关... 【英文摘要】 The surface sediments were collected at nine stations in the Chukchi shelf onboard the R/V Xuelong during chinese first arctic expedition. Activity concentrations of 210 Pb, 226 Ra, 238 U, 137 Cs, 40 K were determined by γ spectrometer with HPGe detector. The results showed that the specific activities of 210 Pb ranged from 16.0 Bq·kg -1 to 76.6Bq·kg -1 , with a mean of 36.9 Bq·kg -1 . The 210 Pb concentrations in study area were lower than those in the low lat...中国首次及第二次北极科学考察基金 ;中国大洋矿产资源研究开发协会国际海底区域研究开发计划 (DY10 5 0 2 0 4;DY10 5 0 2 0 1

Effect of RF power on the structure and properties of ZnO∶Al films deposited by magnetron sputtering

采用RF磁控溅射技术以ZnO:Al2O3(2 wt%Al2O3)为靶材在石英玻璃衬底上制备多晶ZnO:Al(AZO)薄膜,通过XRD、AFM、AES以及Hall效应、透射光谱、折射率等手段研究了RF溅射功率(50~300 W)对薄膜的组织结构和电学,光学性能的影响。分析表明:所制备的AZO薄膜具有c轴择优取向,并且通过对不同功率下薄膜载流子浓度与迁移率的研究发现对于室温下沉积的AZO薄膜,晶粒间界中的O原子吸附是影响薄膜电学性能的主要因素。同时发现当功率为250 W时薄膜的电阻率降至最低(3.995×10-3Ω.cm),可见光区平均透射率为91%。Aluminum doped zinc oxide films are deposited by magnetron sputtering using a zinc oxide target doped with Al2O3(2 wt%.) with different RF powers on quartz substrate.The structural and compositional characteristics of the films are investigated by XRD,AFM,SEM,AES and XPS.respctively,while the electrical and optical properties of the thin films are studied by the Hall measurement and spectrophotometry,respectively.It has been found that all films deposited are c-axis preferred orientation perpendicular to the substrate with porous crystalline structure.The lowest resistivity obtained in this study is 3.9×10-3 Ω·cm for the film deposited at 250 W,and the average transmittance is 91% in the visible range.By comparing the samples deposited at various RF power,the oxygen absorption in the grain boundaries is the dominant factor which influences the electrical property of the AZO thin film

Structural,Electrical,and Optical Properties of Transparent Conductive Al-Doped ZnO Films Prepared by RF Magnetron Sputtering

室温下采用RF磁控溅射技术在石英衬底上制备了多晶ZnO:Al(AZO)透明导电薄膜,通过XRD,AFM,AES,Hall效应及透射光谱等测试研究了RF溅射功率、氩气压强对薄膜的结构、电学和光学性能的影响.分析表明:在最优条件下(溅射功率为250W,氩气压强为1.2Pa时),180nmAZO薄膜的电阻率为2.68×10-3Ω.cm,可见光区平均透射率为90%,适合作为发光二极管和太阳能电池的透明电极.所制备的AZO薄膜具有c轴择优取向,晶粒间界中的O原子吸附是限制薄膜电学性能的主要因素.Highly conductive transparent Al-doped zinc oxide(AZO)films with highly(002)-preferred orientation were successfully deposited on glass substrates at room temperature by RF magnetron sputtering.Optimization of deposition parameters was based on sputtering RF power and Ar pressure in the vacuum chamber.AZO films of 180nm with an electrical resistivity as low as 2.68×10-3 Ω·cm and an average optical transmission of 90% in the visible range were obtained at RF power of 250W and Ar pressure of 1.2Pa.The effect of chemisorption of oxygen on the grain boundary would capture electrons from conduction band and lead the formation of potential barriers among the crystallites,which will influence the electric property of the AZO thin films.The films have satisfactory properties of low resistance and high transmittance for application as transparent conductive electrodes in light emitting diodes(LEDs)and solar cells

Biological nitrogen fixation in the upper water column in the south Taiwan Strait during summer 2011

2011年6—7月,利用15n2示踪法实测了台湾海峡南部海域的生物固氮速率,结合温度、盐度、天然颗粒物氮同位素组成的分布,分析并讨论了影响研究海域生物固氮速率的环境因素。结果表明,夏季台湾海峡南部海域的生物固氮速率介于168—1080 nMOl M-3d-1之间,平均为537 nMOl M-3d-1,较高的生物固氮速率大多出现在次表层水体中。研究站位的积分固氮速率变化范围为11—40μMOl M-2d-1,平均为23μMOl M-2d-1。积分固氮速率的空间变化与不同水团的影响有关,在受黑潮水影响的海域,生物固氮速率较高,而在上升流和受河流冲淡水影响的海域,生物固氮速率较低,说明较低的水温及较高的无机氮营养盐可能会抑制研究海域的生物固氮作用。研究海域天然颗粒物δ15n与生物固氮速率之间呈现良好的负相关关系,表明天然颗粒物氮同位素组成可定性指征研究海域生物固氮作用的强弱。Biological N2fixation in marine environments is a major component in the ocean nitrogen budget and plays an important role in global carbon cycles through the sequestration of atmospheric carbon dioxide and production of marine organic matter.N2fixation could be regulated by the abundance and chemical speciation of nutrients and many trace elements in seawater.Recent studies have revealed that N2fixation is much more widespread in marine environments than previously thought.However,little is known about the N2fixation in the Taiwan Strait,especially on N2fixation rates,and their relationship with environmental parameters.The major objectives of this study were to determine the N2fixation rates and their spatial distributions and to explore major physicochemical controlling factors in the south Taiwan Strait.During June and July 2011,seawater samples were collected from ten stations at two transects in the south Taiwan Strait for the measurements of N2fixation rate using the15N2tracer assay.Particulate nitrogen and its isotopic composition were measured with an elemental analyzer(Carlo Erba NC 2500) coupled with a Finnigan MAT DeltaplusXP isotope ratio mass spectrometer.Reproducibility of nitrogen isotope measurements(in terms of δ15N) was within 0.2‰.Our results showed that N2fixation rates in the south Taiwan Strait ranged from 168—1080 nmol m-3d-1with an average of 537 nmol m-3d-1.Most of the high rates were observed at subsurface layers.The depth-integrated N2fixation rates were 11—40 μmol m-2d-1with an average of(23±10) μmol m-2d-1.The distribution of the N2fixation rates showed regional variations with influence from water masses with distinctive temperature and salinity.Higher N2fixation rates were mostly observed in the regions influenced by the Kuroshio,with an average of 31 μmol m-2d-1,while lower rates occurred in the upwelling and river plume regions with an average of 15 μmol m-2d-1.This spatial distribution pattern indicated that biological N2fixation was largely impeded by the low temperature and the high concentration of dissolved inorganic nitrogen in the south Taiwan Strait.The contribution of N2fixation in the study area could be further quantified based on the δ15N signatures of suspended particles which could be significantly depleted during N2fixation.Indeed,a negative correlation between the δ15N signatures of suspended particles and N2fixation rates was observed regardless of using all data points or depth-averaged values within the water column.This indicated that15N-depleted particles were largely derived from the enhanced N2fixation,supporting the use of nitrogen isotopic composition(δ15N) of suspended particles as a potential indicator of N2fixation in the south Taiwan Strait.Further studies are needed to better elucidate the relationship between N2fixation rates and limiting elements and their chemical speciation,and thus the physical and biogeochemical controls on N2fixation in the south Taiwan Strait.国家自然科学基金资助项目(41125020;41076043;41206062); 国际海域资源调查与开发“十二五”项目(DY125-13-E-01

南沙海域表层水中~(210)Po/~(210)Pb不平衡及其海洋学意义

对南沙海域表层水中溶解态(0.45μm)210Po和210Pb进行了研究.结果表明,南沙海域表层水中溶解态和颗粒态210Po平均比活度分别为0.61Bq/m3(n=24)和0.43Bq/m3(n=23).溶解态和颗粒态210Pb平均比活度分别为1.66Bq/m3(n=24)和0.23Bq/m3(n=23).颗粒态210Pb比活度约占总210Pb比活度的12%,与开阔大洋相应值吻合;而颗粒态210Po占总210Po的比例约40%,明显高于开阔大洋和富营养海域.根据稳态不可逆模型得到总210Po和210Pb的停留时间分别为0.82和1.16a.清除过程中210Po和210Pb的平均分馏因子由清除速率常数法和固-液分配系数法计算分别为5.42和6.69,揭示了210Po和210Pb从溶解相清除至颗粒相的过程中发生了明显的分馏.进一步的研究证明了南沙海域210Po和210Pb的分馏主要由微生物控制,与富营养海域的分馏机制不同:在富营养海域,浮游植物颗粒和粪粒充当210Po和210Pb清除和迁出过程的主要载体,210Po和210Pb的分馏主要发生于浮游植物颗粒和粪粒对两核素的清除过程;在寡营...国家自然科学基金(批准号:40576037,90411016,40376021);; 南沙“十五”国家专项基金(2001DIA50041-4-303)资助项

Studies of the Mg-Al and Cation-Incorporated Hydrotalcites

研究了掺杂阳离子水滑石的制备及阳离子对水滑石性质的影响.分别制备了掺杂Zn2+、Ni2+、Fe3+型的水滑石,考察了掺杂阳离子对水滑石晶相结构、层间距、层间阴离子含量、水滑石表面形态、水滑石碱性的影响,结果表明,由于阳离子的引入,导致水滑石层间距减小及层间阴离子结合量降低,且使水滑石培烧产物电负性提高,并最终降低其碱性.以上述水滑石培烧产物作为固体碱催化剂促进苯甲醛和丙醛缩合,合成α-甲基肉桂醛,关联了水滑石培烧产物碱性与反应活性的关系.Mg-Al and cation-incorporated(containing Zn2+?Ni2+?Fe3+) hydrotalcites were synthesized and characterized. A detailed comparative analysis of structure and composition was made. Different cations influenced strongly textural parameters of hydrotalcites and the basicity of the obtained Mg-Al oxides after calcinations. With the cation incorporation, the distance of the brucite and the mount of CO2-3 as the compensating anion changed. Meanwhile the CO2-TPD was used to determine the basicity of the samples. The results showed that the basicity of the calcined hydrotalcites reduced. Finally, the activated hydrotalcite catalysts may efficiently replace homogeneous catalysts in Claisen-Schmidt condensation reaction of the benzaldehyde and propanal. And it was noteworthy that the calcined cation-type(containing Zn2+?Fe3+) hydrotalcites as catalysts did not show significant activity, in agreement with their low basicity.国家自然科学基金(20203014)资助项