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

最小对称熵鞅测度和不完备市场中的定价问题

在等价鞅测度集Me≠的条件下,文章给出了最小对称熵鞅测度的概念.利用这一新的准则,确定了鞅测度,提供了存在惟一最小对称熵鞅测度的充分条件.进一步,刻画了最小对称熵鞅测度密度的特征.最后,在不完备市场的条件下,讨论了对称熵最小化和效用函数最大化的等价性

Theoretical Model to Compute Specific Area of Activated Carbon

在分析比较各种吸附理论的基础上,介绍5种可用于计算活性炭比表面积的吸附等温方程式,并实际计算6种不同类型活性炭的比表面积.结果表明:不同吸附等温式之间的差异在16%以内.Adsorption isothem equations which are suited to calculate the specific area of activated carbon are recommended based on the analysis and the comparison of various adsorptive theoriesThe specific areas of six activated carbons of different types are computerd by beans of five adsorption isothem equations separatelyThe results showed that the maximum deviation within 16% among calculation values of six carbons in terms of five different adsorptive models国家自然科学基金资助项目(30271057)

局部风险最小下保险合约的套期保值

单位联系保险合约的偿付额与金融市场中某特定股票的价格有关,我们考虑一同时描述金融市场和保险群体不确定性的模型,其不完全性来源于股价的混合扩散和保险个体的死亡,我们给出该模型下的最小鞅测度并在局部风险最小准则下考查单位联系寿险合约的套期保值问题

电视新闻收视率:质量为王——美国地方电视新闻质量危机调查报告

美国的地方电视新闻已经走到了十字路口。观众正在放弃传统媒体,更多地转向了因特网。正如10年前,有线电视的出现导致电视新闻网失去了大量的观众一样。然而电视工业对此所做出的反应却使它走上了一条致命的错误之路。一项针对美国地方电视台新闻的研究揭示出这样一种情况:现在地方电视台新闻节目的经营方

Optical System for Asymmetrical Crossed Czerny-Turner Raman Spectrometer with High Luminous Flux

为克服分立式便携拉曼光谱仪光通量低的缺点,设计了一种集拉曼探头光路与分光系统于一体的光学系统。探头光路采用大数值孔径的非球面透镜实现样品的有效激发和信号的高效收集,通过胶合透镜组缩小会聚光路尺寸、消除轴向色差。分光系统基于交叉非对称Czerny-Turner结构,为获得期望的光谱分辨率和光谱范围,建立了分光系统光谱分辨率及光谱范围与交叉非对称Czerny-Turner结构参数的关系。由测得的汞灯谱图可知,分光系统的光谱分辨率优于6 cm~(-1)(0.37 nm),光谱范围为790~950 nm(200~2000 cm~(-1))。将设计的光学系统对CCL4进行测试,实验结果表明在相同积分时间内由这种整体式的光学系统检测到的CCL4光谱谱峰强度是用商业探头通过光纤连接分光系统检测到的近3倍,验证了光学系统设计的合理性。To overcome the low luminous flux in separated portable Raman spectrometer, an optical system embodies the probe of Raman spectrometer and monochromator is designed. An aspherical lens with high numerical aperture is used to obtain the effective excitation of sample and the efficient collection of signal in the optical system of the probe. A cemented lens group is used to minish the size of converging path and eliminate chromatic aberration.The monochromator is based on asymmetrical crossed Czerny-Turner structure. For the purpose of achieving desired spectrum resolution and spectrum range, the relationship between the spectrum resolution and spectrum range of the monochromator and the structural parameters of the asymmetrical crossed Czerny-Turner system is established. According to the tested spectrogram of mercury lamp, the spectrum resolution of the monochromator is better than 6 cm~(-1)(0.37 nm), and spectrum range is 790~950 nm(200~2000 cm~(-1)). A sample of CCL4 is introduced to examine the performance of the optical system, the experimented results demonstrate that the peak intensity of spectrogram of CCL4 measured by this incorporative optical system is almost three times as high as that using a commercial probe couples to the monochromator, which verifies the rationality of the design of the optical system.国家自然科学基金(21503171);; 中央高校基本科研业务费项目(20720150091、20720150094);; 福建省高端装备制造协同创新中心资

Preparation of agricultural low-cost super water absorbent

概述了合成类吸水树脂在农用上的进展,提出采用低成本且工艺成熟的水溶液法,以丙烯酸(AA)、丙烯酰胺(AM)为基体、接枝可溶性淀粉进行三元单体共聚,经钠基膨润土改性,复合引发剂、复合交联剂制备低成本、易降解的合成类吸水性树脂。经实验改进和工艺条件优化后,树脂吸去离子水倍率可达1 940.9 g/g,吸自来水899.8g/g。采用红外光谱仪、热重分析仪、扫描电镜、X射线衍射仪等分析手段对合成树脂进行了分析表征,证实了产物为淀粉、丙烯酸及丙烯酰胺的共聚物。The utilization status of the synthetic absorbent resin in agricultural applications was summarized.An improved process of three monomer copolymer system was proposed by using an aqueous solution polymerization.These three monomers are soluble starch,acrylic acid and acrylamide,which are modified by sodium bentonite,using a composite initiator and cross-linker.By improving the experiments and optimizing the process conditions,the absorption rate of the synthetic absorbent resins is up to 1 940.9 g/g in deionized water,and 899.8 g/g in tap water.In addition,the structure and performance of the synthetic absorbent resin were characterized by using infrared spectroscopy,thermal gravimetric analysis,scanning electron microscopy and X-ray diffraction,which shows that it is an copolymer of starch,acrylic acid and acrylamide

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

金属Cu表面三维齿状微图形的复制加工——约束刻蚀剂层技术 (CELT)的应用

主要介绍了一种Cu的CELT加工的化学刻蚀体系和捕捉体系 ,并通过控制刻蚀时间、刻蚀电流、刻蚀剂浓度、捕捉剂浓度等实验参数和优化电化学模板的制作工艺 ,以规整的齿状结构为模板 ,在Cu的表面实现了三维微结构的复制加工 ,得到了与齿状结构模板互补的三维微结构 ,用SEM和AFM对实验结果进行了表征 ,表征结果证明约束刻蚀剂层技术在金属三维加工方面的可行性和潜在优势。金属Cu由于具有优良的导热导电性能以及很好的延展性 ,在微系统 (也称微机电系统 )中应用广泛 ,因此对Cu的刻蚀加工对微系统技术的发展具有重要的意义。约束刻蚀剂层技术 (ConfinedEtch antLayerTechnique简称CELT)作为一种新型的微加工技术[1] ,能够加工复制出复杂三维结构 ,到目前为止 ,该技术已成功应用于Si、GaAs等材料微结构的复制加工[2 ,3]

Optimization of Hydrometallurgical Purification for SiO_2 in the Process of Preparing Solar-grade Silicon

考察了Hf质量分数、H2C2O4质量分数、HnO3质量分数、酸浸时间、粒径、液体质量与固体质量的比值(简称液固比,下同)等因素对混酸法提纯SIO2工艺过程的影响,利用电感耦合等离子体发射光谱仪(ICP-OES)、场发射扫描电子显微镜(SEM)进行表征。结果表明,最佳工艺条件为:W(Hf)=2%、W(H2C2O4)=3%、W(HnO3)=30%、酸浸时间4 H、粒径100~120目、液固比4∶1、酸浸温度30℃。fE、Al、CA、P杂质的去除率分别达到99.99%、14.02%、73.27%、60.00%,经混酸法处理后SIO2中杂质总量的质量分数降至1.465x10-4。As a pre-treatment unit for preparing solar-grade silicon,hydrometallurgical route could remove most metallic impurities in silicon dioxide(SiO2) and raise the yield of the final product.Acid leaching of SiO2 could reduce the cost and energy consumption of industrialized development.Combined with high purity of reducing agent,the successor process of pyrometallurgy can also achieve "continuous casting".Factors such as the mass fraction of leaching agent,time,the particle size of SiO2,and the liquid-solid ratio were investigated,and the samples were characterized by means of ICP-OES,SEM,etc.The optimal reaction conditions were as follows:w(HF)=2%,w(H2C2O4)=3%,w(HNO3)=30%,reaction time 4 h,the average size of SiO2 powder particle 100～120 mesh,the liquid-solid ratio 4∶1,and room temperature 30 ℃.It was found that the final removal rates of impurities of Fe,Al,Ca,P could reach 99.99%,14.02%,73.27%,and 60.00% respectively and the mass fraction of total amount of impurities could be reduced to 1.465×10-4