The Geological Roles and Isotopic Responses of the Extremophiles in the Modern Ocean

围绕现代海洋极端环境条件下微生物分布特征和环境因子相互关系的研究在前期工作积累的基础上进行了更深入的分析,通过对北极冰川前沿和西南印度洋深海微生物资源的调查,初步了解了微生物群落结构的多样性及微生物的部分生态功能,为探索地质历史时期的微生物生命过程提供了良好的资源;发现西南印度洋深海微生物群落结构与钙、磷、硫等元素具有相关性,为揭示深海微生物的地球化学循环创造了条件;对深海环境铁还原菌的研究对探讨古海洋环境与生命的协同演化具有重要意义。开展了微生物对模拟环境条件如海洋酸化及火山爆发等地球历史时期的重大地质突变事件为背景,在现代海洋环境中进行了一系列的模拟研究,针对目前研究相对薄弱的环节,重点研究了海洋酸化及火山灰添加对浮游异养细菌的影响,初步揭示了浮游细菌对大气CO_2升高及火山爆发事件的反馈,完善了地质突变期海洋生态系统反馈的认识。另外,在深部生物圈MCG古菌的研究上取得了重要进展。MCG是迄今为止发现分布最为广泛的一类未培养古菌,被认为是海底深部生物圈中最丰富,并且最活跃的类群之一,很可能在全球物质和能量循环过程中发挥了重要的作用。课题组发现MCG古菌在系统发育上处于一个深的分支,代表了一类自然界较古老的古菌,显著不同于目前分类已确定的所有古菌门类,并提议将MCG古菌归类于一个全新的门类,命名为深古菌门(Bathyarchaeota)。这是目前首个由中国学者提议的古菌门的分类,是古菌和生命起源和演化研究的重要进展之一,也将为该领域的科学研究起到积极推动作用。We conducted further investigations on the microbial distribution characteristics and its relation with environmental factors, mainly on Actic ice front area and South-west Indian deep ocean. Our results revealed the dynamic microbial community structures and the ecological functions of some microbial groups, thus provided precious biological materials to explore the geological functions of microorganisms in the Earth history. Meanwhile, the microbial structure in the Southwest Indian deep ocean was found to be related with some elements including Calcium、Phosphorus、and Sulfur, providing data and research basis for further scientific studies on revealing the biogeochemical roles of marine microorganisms. We conducted a series of environmental simulating experiments such as marine acidification and volcanic eruption which represent important geological events in the earth history. We focused on the responses of planktonic heterotrophic bacteria towards marine acidification and supplementing with volcanic ashes, our study supplements current understanding on the responses of marine ecosystem in the geological disrupting events. Moreover, we have made significant progresses on MCG archaea in the deep subsurface biosphere. MCG is one of the most widely distributed cosmopolitan uncultivated archaea, regarded as the most abundant and active archaeal group. MCG is probably playing important roles in the biogeochemical roles on Earth. We found that MCG is placed in a deep branch on the phylogenetic tree, representing an ancient group of archaea, and distinct from all known archaeal Phylum. Therefore, we propose to name MCG as a novel archaeal Phylum as "Bathyarchaeota". Proposing of MCG into a new archaeal phylum would stimulate research interests in this unknown fascinating archaeal group

Microbial processes and mechanisms in carbon sequestration in the ocean

在全球气候环境演变的背景下,认识海洋微型生物对碳循环的贡献,需要了解其过程和机制。最近提出的“微型生物碳泵“理论阐释了海洋储碳的一个新机制:微型生物活动把溶解有机碳从活性向惰性转化,从而构成了海洋储碳。这个过程当中,自养与异养细菌、病毒、原生动物等具有不同生理特性微型生物类群扮演着不同的生态角色,本文将围绕微型生物碳泵主线分别论述之。The oceans are full of microorganisms,which play a significant role in global carbon cycle.Microbial carbon sequestration in the ocean,as a cutting-edge scientific issue,receives a great deal attention in the context of global climate change.Based on the microbial carbon pump conceptual framework,microbes are major producers of recalcitrant dissolved organic carbon(RDOC) that can stay in ocean water column for long time storage.Different microbial groups contribute to RDOC carbon pool in different ways.This paper addresses groups such as autotrophic and heterotrophic microorganisms,viruses and protozoa with respect to their various ecological characteristics and specific roles in RDOC formation.国家重大科学研究计划项目(No.2013CB955700); 国家自然科学基金项目(No.91028001;41276131;41176095;40906059); 国家海洋局公益性项目(No.201105021

海洋储碳机制及区域碳氮硫循环耦合对全球变化的响应

海洋作为地球表面最大的活跃碳库,其碳收支在很大程度上决定了全球气候变化的走向.然而,海洋碳循环是一个多时空尺度的过程,相关的碳收支估算存在很大的; 不确定性,其控制过程与机理更是一个颇具挑战性的难题(胡敦欣等, 2015),特别是海洋储碳机制,是研究全球变化及应对的核心内容之一.国家重点研发计划专项全球变化及应对项

Alloy Conditions Impact on Al/n~+-Ge Ohmic Contact

gE比SI具有更高的电子和空穴迁移率,且gE材料可以应用于1.3~1.5μM近红外波段,因此gE成为制备微电子和光电子器件的主要材料。然而由于gE的费密能级钉扎效应以及难以获得高浓度的磷(P)原位掺杂,使得n-gE的欧姆接触成为一个难题。采用P+离子注入获得高掺杂浓度的n-gE材料,掺杂浓度为1.5x1019CM-3;依据圆形传输线模型(CTlM)制备了一系列Al/n+-gE样品,研究了不同退火温度和退火方式对其接触特性的影响。实验结果表明,Al/n+-gE样品通过400℃快速热退火(rTA)30 S表现出欧姆接触特性,并且接触电阻率ρC最低,为1.3x10-5Ω·CM2。Germanium is used as the primary material on the micro-or opto-electronic devices,due to the much higher electron and hole mobility compared to Si,as well as its favorable absorption coefficient in the near infrared wavelength regime(1.3-1.5 μm).However,the ohmic contact formation on n-type Ge is still a challenge because of the severe Fermi level pinning effect of n-Ge and the low concentration of P-situ doping.Heavily-doped n-type Ge was achieved with phosphorus concentration of 1.5×1019cm-3 by the ion implantation.And then a series of Al/n+-Ge samples were prepared according to circular transmission line model(CTLM).The samples were annealed at different temperatures and with different annealing ways to analyze the contact characteristics.The test result indicate that the Al/n+-Ge contacts show ohmic characteristics by rapid thermal annealing(RTA) at 400 ℃ for 30 s,with the lowest contact resistivity ρc of 1.3×10-5 Ω·cm2.国家自然科学基金资助项目(61176050;61036003;61176092;60837001); 国家重点基础研究发展计划资助项目(2012CB933503;2013CB632103); 福建省基础研究基金资助项目(2012H0038); 中央高校基本科研基金资助项目(2010121056

GaN LED/metals/Si structure fabricated by bonding and laser-lift off

采用金属键合技术结合激光剥离技术将gAn基lEd从蓝宝石衬底成功转移到SI衬底上。利用X射线光电子谱(XPS)研究不同阻挡层对Au向gAn扩散所起的阻挡作用,确定键合所需的金属过渡层。利用多层金属过渡层,在真空、温度400℃和加压300 n下实现gAn基lEd和SI的键合,通过激光剥离技术将蓝宝石衬底从键合结构上剥离下来,形成gAn基lEd/金属层/SI结构。用金相显微镜及原子力显微镜(AfM)观察结构的表面形貌,测得表面粗糙度(rMS)为12.1 nM。X射线衍射(Xrd)和rAMAn测试结果表明,衬底转移后,gAn基lEd的结构及其晶体质量没有发生明显变化,而且gAn与蓝宝石衬底间的压应力得到了释放,使得SI衬底上gAn基lEd的电致发光(El)波长发生红移现象。The effect of different barrier layers on gold diffusing into GaN is analyzed by X-ray photoelectron spectroscopy(XPS).By using wafer bonding and laser lift-off(LLO),which uses a KrF excimer laser(248 nm) to separate GaN LED from sapphire substrate,an light emitting diode(LED) GaN epi layer is successfully transferred onto a Si substrate at the temperature of 400 ℃.The surface of samples after laser lift-off(LLO) is observed with microscope and atomic force microscope(AFM).The root-mean-square roughness of the transferred GaN LED surface is about 12.1 nm.The X-ray diffraction(XRD) and Raman test results show that the quality of LED on Si substrate has not obviously change,but the electroluminescence peak wavelength of GaN-based LED on Si substrate showes a red shift compared to that on sapphire substrate.国家自然科学基金重点基金资助项目(60837001);福建省自然科学基金资助项目(2008J0221);福建省教育厅科技项目(JB08215

海洋微型生物碳泵储碳机制及气候效应

海洋中存在一个巨大的惰性溶解有机碳(rdOC)库,可与大气CO2碳量相媲美.两个碳库之间的交换势必影响气候变化.rdOC可在海洋中保存数千年,构成了海洋储碳的重要机制.探寻rdOC碳库形成机制是认识海洋如何储碳的关键.新近提出的“海洋微型生物碳泵(MICrObIAl CArbOn PuMP,MCP)“理论指出,海洋微型生物是rdOC碳库的主要贡献者.本文从MCP的主动机制和被动机制及其环境调控出发,论述了海洋rdOC的组成与生物来源,rdOC组分的微型生物代谢途径,病毒的裂解过程以及浮游动物活动对rdOC生产的贡献,不同类群微型生物有机碳代谢特征及其生物标记物与碳氢同位素表征,以及MCP的能量代谢特征与储碳效率,并结合MCP储碳的地史证据展望了MCP在增加海洋储碳能力方面的应用前景.国家自然科学基金(批准号:91028001); 国家重大科学计划(编号:2013CB955700); 国家自然科学基金(批准号:91028005;91028011;41172030;41076091); 国家海洋公益性行业科研专项(批准号:201105021)资

引导方式对高速圆柱滚子轴承保持架动态性能的影响

针对高速圆柱滚子轴承保持架在引导方式选用上存在分歧的问题，基于Adore建立了高速圆柱滚子轴承的仿真模型，分析了保持架在外引导和内引导方式下，滚子数量、径向游隙、保持架引导间隙和兜孔间隙对保持架打滑及运转稳定性的影响，并通过高速轴承打滑试验验证了仿真模型的可靠性。结果表明，在内圈旋转的情况下，内引导方式比外引导方式更有利于防止保持架打滑；内引导方式下，采用较小的轴承径向游隙和引导间隙可以降低保持架的打滑率，并提高其运转稳定性；兜孔间隙对保持架打滑几乎没有影响，但是随着兜孔间隙的增大，保持架运转稳定性变差

Draft Genome Sequence of Oceaniovalibus guishaninsula JLT2003(T)

NSFC [41276131, 40906079]; SOA [201105021]; Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education of ChinaOceaniovalibus guishaninsula, as a representative of a new genus within the family Rhodobacteraceae, was isolated from surface seawater that was sulfidic. Here, we present the draft genome sequence of the type strain, JLT2003(T)