217 research outputs found
The Relationship of Environmental Factors with Community Structures and Diversities of Microorganisms in Activated Sludge from Wastewater Treatment Plants
随着我国社会经济的飞速发展和城镇化进程的加快,大量肆意排放的废水造成水体严重污染,导致“水危机”日趋严重。废水在排入水体前,应首先由污水处理厂进行处理。较之于增加污水处理厂数量需要耗费大量资金成本,提高现有污水处理设施的废水处理效率至关重要。活性污泥法是污水处理厂应用最广泛的废水处理方式之一。由于在活性污泥系统中,微生物是去除污染物的主体。因此,深入了解活性污泥中微生物的群落结构与功能,理解其时空分布格局及受控机理,对于深化认识污水处理系统的本质,进而提高污水处理效率具有重要意义。此外,由于活性污泥中还存在着大量的重金属、病原微生物和寄生虫卵等,因此污水处理厂每年产生的巨量剩余污泥的处理和处置...A large amount of wastewater discharged has led to the continuous water pollution and brought about a severe “water crisis” as the rapid economic development and accelerated urbanization process Wastewater should be treated by wastewater treatment plants (WWTPs) before discharged. Improving the efficiency of WWTPs have a significance on wastewater treatment since much capital is needed by increasi...学位:理学硕士院系专业:生命科学学院_微生物学学号:2162010115238
海洋微生物与噬菌体间的相互关系
病毒是海洋中丰度最高的生物体,其中绝大多数又为能够侵染细菌和古菌的噬菌体.它们在控制微生物死亡率、调节微生物群落结构与多样性、影响微食物网过程以及参与碳、氮等元素的生物地球化学循环等方面扮演着重要的生态角色.本文对近年来关于海洋细菌与其病毒间相互关系的研究进行了概述,并结合作者的工作对未来的研究进行展望.国家自然科学基金(41006087;91028001;41076063);近海海洋环境科学国家重点实验室(厦门大学)青年访问学者基金(MELRS0932);福建省科技计划重点项目(2009Y0044)资
Reviews on Ecosystem Services Valuation and GIS-Based Mapping
生态系统服务价值评估是当前生态经济学领域的研究热点,为解决生态系统对人类的重要性提供了量化参考。文章论述了国内外生态系统服务价值的评估方法,分别从静态评估、动态评估和gIS技术应用三大方面进行了归纳分析,提出今后应重点关注生态系统服务价值的时空动态模型开发、评价指标体系与评价方法的标准化制订和生态系统综合管理与应用等方面的研究。Ecosystem services valuation has become one of the hotspots in the field of ecological economics,and provides quantitative evidence concerning the importance of the ecosystem for human-beings.In this paper,we first discussed ESV method in static,dynamic and GIS based respectively.We pointed out that scientific community should focus on several topics in the near future to deepen the understanding of the values of ecosystems.These topics include the development of spatially and temporarily explicit dynamic valuation models,standardization of valuation methods and payment for ES and meeting the requirements of regional ecosystem management and decision making.北京市科学技术委员会“永定河生态修复目标体系研究”(D090409004009003);北京市生态学重点学科项
Anti-resonance features of destructive quantum interference in single-molecule thiophene junctions achieved by electrochemical gating
基于单个有机分子来构筑电子器件为电子器件微型化提供潜在技术方案。本研究发展了可集成电化学门控的单分子电子器件测试芯片技术和科学仪器方法,在实验和理论两个层面对具有相消量子干涉效应的噻吩衍生物分子器件的电输运过程进行了电化学调控研究,从而首次在室温下实现了对单分子电子器件中量子干涉效应的反共振现象的直接观测和调控,为制备基于量子干涉效应的新型分子材料和器件提供了全新的设计思路和策略。该研究充分展示了电化学调控技术在信息材料和器件领域的重要应用潜力,也体现了我校固体表面物理化学国家重点实验室在电化学研究和科学仪器研发领域的技术积累,以及面向科学前沿开展交叉学科探索的研究特色。
该研究工作是在洪文晶教授、上海电力大学陈文博教授、英国兰卡斯特大学Colin Lambert教授指导下完成的。化学化工学院博士生白杰和李晓慧为论文的共同第一作者,刘俊扬副研究员、师佳副教授、研究生唐永翔、刘帅、黄晓娟、谭志冰和萨本栋微纳研究院的杨杨副教授等也参与了研究工作。田中群教授和毛秉伟教授为该工作提供了重要指导。【Abstract】Controlling the electrical conductance and in particular the occurrence of quantum interference in single-molecule junctions through gating effects, has potential for the realization of high-performance functional molecular devices. In this work, we used an electrochemically-gated, mechanically-controllable break junction technique to tune the electronic behaviour of thiophene-based molecular junctions that show destructive quantum interference (DQI) features. By varying the voltage applied to the electrochemical gate at room temperature, we reached a conductance minimum that provides direct evidence of charge transport controlled by an anti-resonance arising from DQI. Our molecular system enables conductance tuning close to two orders of magnitude within the non-faradaic potential region, which is significantly higher than that achieved with molecules not showing DQI. Our experimental results, interpreted using quantum transport theory, demonstrate that electrochemical gating is a promising strategy for obtaining improved in-situ control over the electrical performance of interference-based molecular devices.This research was supported by the National Key R&D Program of China (2017YFA0204902), National Natural Science Foundation of China (21722305, 21673195, 21503179, 21703188), the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, Natural Science Foundation of Shanghai (17ZR1447100), Science and Technology Commission of Shanghai Municipality (14DZ2261000), China Postdoctoral Science Foundation (2017M622060) for funding work in Xiamen. It was also supported by EU Horizon 2020 project QuIET under grant agreement no. 767187EC FP7 ITN ‘MOLESCO’ project no. 606728 and UK EPSRC grants EP/N017188/1 and EP/M014452/1 and Leverhulme Trust (Leverhulme Early Career Fellowships no. ECF-2017-186 and ECF-2018-375) for funding instrumentation used in Lancaster. It was also supported by Hungarian and Czech Academies of Sciences (P2015-107) and Hungarian Research Foundation (OTKA 112034) for funding instrumentation used in Hungary. The authors thank Z.-Q. Tian and B.-W. Mao, Xiamen University, for useful discussions.
该工作获得科技部国家重点研发计划课题(2017YFA0204902),国家自然科学基金委优秀青年科学基金等项目(21722305、21673195、21703188、21503179)以及中国博士后科学基金(2017M622060)等项目的资助,也得到了固体表面物理化学国家重点实验室、能源材料化学协同创新中心的支持
CCCCC pentadentate chelates with planar Möbius aromaticity and unique properties
本课题充分发挥了厦门大学多学科协同研究优势,通讯作者为夏海平教授(合成、表征)、刘刚教授(生物医学应用)和吕鑫教授(理论计算)。合成实验和结构表征由朱从青(第一作者,目前在麻省理工学院、2005年诺贝尔化学奖得主Richard Schrock教授课题组从事博士后研究)完成;生物医学应用由杨彩霞(共同第一作者)、林凎、杨宇惠、王晓勇合作完成;理论计算由朱军、王永恒、朱从青完成。美国NIH的陈小元教授参与了生物医学应用的讨论。该研究工作得到国家自然科学基金委、科技部项目的支持。The coordinating atoms in polydentate chelates are primarily heteroatoms. We present the first examples of pentadentate chelates with all binding atoms of the chelating agent being carbon atoms, denoted as CCCCC chelates. Having up to five metal-carbon bonds in the equatorial plane has not been previously observed in transition metal chemistry. Density functional theory calculations showed that the planar metallacycle has extended Craig-Möbius aromaticity arising from 12-center–12-electron dπ-pπ π-conjugation. These planar chelates have broad absorption in the ultraviolet-visible–near-infrared region and, thus, notable photothermal performance upon irradiation by an 808-nm laser, indicating that these chelates have potential applications in photothermal therapy. The combination of facile synthesis, high stability, and broad absorption of these complexes could make the polydentate carbon chain a novel building block in coordination chemistry.the National Basic Research Program of China (nos. 2012CB821600 and 2014CB744503) , the National Science Foundation of China (nos. 21332002, 81422023, 51273165, 21490573, and 21573179)
Transition from tunneling leakage current to molecular tunneling in single-molecule junctions
数十年来,半导体工业一直遵循基于“摩尔定律”所设定的发展蓝图,逐步提升集成电路芯片上晶体管的集成度和运行速度,减小器件尺寸。为探索这一尺寸极限,课题组基于机械可控裂结技术自主开发了具有飞安级电学测量和亚纳米级位移控制灵敏度的科学仪器,在国际上首次获取了一系列具有不同重复单元的寡聚苯乙炔类分子电导随电极间距的演变关系,并发现随着电极间距的缩小,器件电输运由通过分子器件电流占主导逐步转变到由隧穿漏电流占主导。对于本研究中具有最小尺寸的寡聚苯乙炔分子器件,其由于隧穿漏电流所制约的尺寸极限可小至0.66 nm,预示了有机分子器件在未来电子器件小型化方面具有重要的应用潜力。
这一研究工作是在化学化工学院洪文晶教授、萨本栋微纳研究院杨扬助理教授以及英国Durham University的MartinR. Bryce教授共同指导下完成的。能源材料化学协同创新中心iChEM Fellow刘俊扬博士为论文第一作者,博士研究生郑珏婷、李瑞豪和硕士研究生黄晓艳、唐永翔、皮九婵、本科生王飞等参与了研究工作。田中群教授、毛秉伟教授和师佳副教授为论文工作提供了重要指导。【Abstract】The tunneling leakage current will be a major quantum obstacle during
miniaturization in the semiconductor industry down to the scale of several
nanometers. At this scale, to promote charge transport and overcome the
tunneling leakage current between the source and drain terminals, molecular
electronic junctions offer opportunities by inserting molecules between these
two electrodes. Employing a series of oligo(aryleneethynylene) (OAE) molecules,
here we investigate the transition from tunneling leakage current to molecular
tunneling in the single-molecule devices using mechanically controllable break
junction (MCBJ) technique, and the transition distances of the OAE molecular
junctions were determined and even down to 0.66 nm for OAE2 molecular
junction, which demonstrates that the intrinsic charge transport properties of a
single-molecule device can be outstripped from the tunneling leakage current.
Consequently, molecular electronic devices show the potential to push the
ultimate limit of miniaturization to the scale of several angstroms.This work was supported by the National Key R&D Program of China (2017YFA0204902). This work was also generously supported by the Young Thousand Talent Project of China, the EC FP7 ITN “MOLESCO” project number 606728, the National Natural Science Foundation of China (nos. 21703188, 21673195, 21503179), and the China Postdoctoral Science Foundation (2017M622060).
该工作获得科技部国家重点研发计划课题(2017YFA0204902),国家自然科学基金委(21673195、21703188、21503179)以及中国博士后科学基金(2017M622060)等项目的资助,也得到了固体表面物理化学国家重点实验室、能源材料化学协同创新中心的支持
改良分子信标-双重实时荧光PCR快速检测SARS病毒
目的建立改良分子信标-双重实时荧光PCR检测SARS病毒的方法,用于SARS的早期诊断和动物溯源。方法利用改良分子信标技术、装甲RNA和双片段双色荧光技术,根据GenBank公布的SARS病毒聚合酶基因1b的阅读开放框架结构的保守序列,自行设计一对引物和探针,以部分临床标本的酶联吸附实验结果和传统细胞培养方法作为对照,建立分子信标检测SARS病毒的方法。对368份临床标本(咽漱液、血液、粪便、尿液)、52份细胞培养液和50份动物标本进行荧光PCR扩增。结果分子信标检测SARS病毒的方法灵敏度为10~100个拷贝ml,与流感病毒等呼吸道病毒无交叉反应。分子信标检测368份临床标本,20份阳性。其中确诊病例阳性率为21.27%(1047),确诊病例的咽漱液阳性率为43.48%,还分别从粪便和血清中检测到SARS病毒。52份细胞培养液,29份阳性,阳性率为55.77%。50份动物标本,23份阳性,阳性率为46%。结论改良分子信标-双重实时荧光PCR检测SARS病毒方法灵敏度高、特异性强,可用于SARS的临床早期诊断和动物溯源
中国物理海洋学研究70年:发展历程、学术成就概览
本文概略评述新中国成立70年来物理海洋学各分支研究领域的发展历程和若干学术成就。中国物理海洋学研究起步于海浪、潮汐、近海环流与水团,以及以风暴潮为主的海洋气象灾害的研究。随着国力的增强,研究领域不断拓展,涌现了大量具有广泛影响力的研究成果,其中包括:提出了被国际广泛采用的"普遍风浪谱"和"涌浪谱",发展了第三代海浪数值模式;提出了"准调和分析方法"和"潮汐潮流永久预报"等潮汐潮流的分析和预报方法;发现并命名了"棉兰老潜流",揭示了东海黑潮的多核结构及其多尺度变异机理等,系统描述了太平洋西边界流系;提出了印度尼西亚贯穿流的南海分支(或称南海贯穿流);不断完善了中国近海陆架环流系统,在南海环流、黑潮及其分支、台湾暖流、闽浙沿岸流、黄海冷水团环流、黄海暖流、渤海环流,以及陆架波方面均取得了深刻的认识;从大气桥和海洋桥两个方面对太平洋–印度洋–大西洋洋际相互作用进行了系统的总结;发展了浅海水团的研究方法,基本摸清了中国近海水团的分布和消长特征与机制,在大洋和极地水团分布及运动研究方面也做出了重要贡献;阐明了南海中尺度涡的宏观特征和生成机制,揭示了中尺度涡的三维结构,定量评估了其全球物质与能量输运能力;基本摸清了中国近海海洋锋的空间分布和季节变化特征,提出了地形、正压不稳定和斜压不稳定等锋面动力学机制;构建了"南海内波潜标观测网",实现了对内波生成–演变–消亡全过程机理的系统认识;发展了湍流的剪切不稳定理论,提出了海流"边缘不稳定"的概念,开发了海洋湍流模式,提出了湍流混合参数化的新方法等;在海洋内部混合机制和能量来源方面取得了新的认识,并阐述了混合对海洋深层环流、营养物质输运等过程的影响;研发了全球浪–潮–流耦合模式,推出一系列海洋与气候模式;发展了可同化主要海洋观测数据的海洋数据同化系统和用于ENSO预报的耦合同化系统;建立了达到国际水准的非地转(水槽/水池)和地转(旋转平台)物理模型实验平台;发展了ENSO预报的误差分析方法,建立了海洋和气候系统年代际变化的理论体系,揭示了中深层海洋对全球气候变化的响应;初步建成了中国近海海洋观测网;持续开展南北极调查研究;建立了台风、风暴潮、巨浪和海啸的业务化预报系统,为中国气象减灾提供保障;突破了国外的海洋技术封锁,研发了万米水深的深水水听器和海洋光学特性系列测量仪器;建立了溢油、危险化学品漂移扩散等预测模型,为伴随海洋资源开发所带来的风险事故的应急处理和预警预报提供科学支撑。文中引用的大量学术成果文献(每位第一作者优选不超过3篇)显示,经过70年的发展,中国物理海洋学研究培养了一支实力雄厚的科研队伍,这是最宝贵的成果。这支队伍必将成为中国物理海洋学研究攀登新高峰的主力军
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