Bacterial Survival Modes and Community Characteristics in Natural Environment

细菌在环境中是以群落的形式存在的,群落中的细菌有多种生存方式.当处于适宜的环境中,细菌通过互作而快速生长,而营养物质的消耗又造成细菌之间的竞争.不同细菌通过复杂的作用形成的群落容易受到外界环境的影响,并且特殊的功能基因也改变了原有的群落结构.细菌群落在环境中有着重要的生态功能及理论与应用价值.本文介绍了细菌的生存方式,结合作者相关研究阐述了细菌群落结构及其生态功能,并予以展望,旨在为细菌群落的深入研究、开发和应用提供参考.Bacteria in the environment live in communities with multiple survival modes.Bacteria in a suitable environment grow rapidly through cooperation,whereas nutrient consumption cause competition.Bacterial communities are vulnerable to the impact of the external environment,and the special functional gene can also change the community structure.Bacterial communities have important ecological functions in the environment and they are both complex and valuable.This paper,by combining the work of our group with literature,tried to elaborate on bacterial survival modes as well as the formation and ecological function of bacterial communities,to provide a reference for the study of bacterial community and to look into the future direction of this field of research.国家自然科学基金重点项目、面上项目(40930847;31070442); 福建省自然科学基金项目(2012J01150); 海洋公益性行业科研专项(201305016;201305041;201305022)资助~

Different roles of the left inferior prefrontal cortex in visual Chinese word recognition

目的利用事件相关功能磁共振成像(functionalMRI)技术比较中文双字真词与假词的认知加工的脑机制。方法14名大学生在MR扫描过程中执行词汇判断任务,用视觉方式随机呈现120个双字词,其中真、假词各60个。结果真、假词的判断激活了相似的包括双侧额下回,颞中回,梭状回和舌回,双侧缘上回,丘脑等区域。其中,左侧额下回(BA4

预涂布晶种法合成无缺陷A型分子筛膜的研究

采用一种颗粒度约为 2 0 0 nm的胶态 A型分子筛为晶种源 ,对晶种层进行特殊的蒸气处理后 ,进一步采取原位水热晶化法 ,在多孔氧化铝载体表面制备出 A型分子筛膜 .膜分子筛以特殊的孪生聚晶形式生长在一起 ,可有效地消除晶粒间隙 ,形成致密的分子筛膜层 .晶化反应液的碱度对 A型分子筛膜的质量影响很大 ,低碱度更有利于 A型分子筛膜的生长 .在对分子筛膜进行高温活化处理过程中产生一些缺陷孔 ,降低了膜气体分离性

红树林土壤中脂肪酶产生菌的筛选及酶学性质

从福建龙海红树林区土壤中分离获得9株产脂肪酶的细菌,经16S rDNA序列分析表明分别属于红球菌属(Rhodococcus)、库克菌属(Kocuria)、假单胞菌属(Pseudomonas)、芽胞杆菌属(Bacillus)和微小杆菌属(Exiguobacteri-um).对9株细菌所产的脂肪酶进行酶学性质研究,结果显示这些酶的最适作用温度在25~35℃、最适作用pH值在8~10,其中L13菌株所产脂肪酶(L′13)具有适应温度和pH范围较广、对多种金属离子耐受性强、能有效降解不同底物等特点,在环境保护和工业生产方面具有良好的应用前景

Application of single poise counterweight method in adjusting grinding uniformity of silicon wafer

为提高硅片研磨的均匀性,提出了一种通过改变调节砝码位置的新方法。对单砝码配重法的原理、步骤及物理模型进行了详细的论述,并基于lAbVIEW软件对该方法进行了可视化。在精密研磨抛光机上进行实验,并用膜厚仪进行均匀性测量。结果表明:在给定的条件下使9.9 CM硅片的均匀性从单靠自重研磨的20μM提高到用配重法调节后的3μM,显著提高了硅片研磨的均匀性。单砝码配重法为解决硅片研磨均匀性问题提供了一种既精确又简便的方法。To improve the grinding uniformity of silicon wafer,this paper proposed a new approach by changing the position of poise.The principle,procedure and physical model of the single poise counterweight method were described in detail,and then the visualization of this method basing on LabVIEW software was realized.Experiment was carried out on a precision grinding and polishing machine,and the thickness uniformity was measured on the thickness monitor.Experimental results show that the uniformity of three inches silicon wafer is improved from 20 μm to 3 μm comparing to conventional deadweight grinding,so the grinding uniformity of silicon wafer is enhanced markedly.Therefore,the single poise counterweight method provides a precise and convenient way to solve the grinding uniformity problem of silicon wafer.航空科学基金(20110868001

软件动态分析与信息系统安全

信息系统的应用越来越广泛,软件被视为信息系统的灵魂,已经在金融、军事、交通、基础设施等领域扮演越来越重要的角色,软件安全性已经成为关系到国民经济平稳发展、社会稳定和国家安全的重要因素。本文分析了国内外软件安全性研究的现状,并对软件安全性分析的主要科学问题和当前我国的重要需求进行了剖析,提出在信息系统安全保障能力建设中,应以加强软件安全性分析能力为导向,以提高软件的安全性分析水平为目标,以软件动态分析为关键技术手段,加强软件安全性分析基础方法研究,加强信息系统安全性分析和保障的专业人才队伍建设,为保障我国信息系统安全和网络空间主权提供技术支撑

Direct numerical simulation of hypersonic boundary layer transition over a lifting body at different angles of sideslip

Hypersonic boundary layer transition on a hypersonic transition research vehicle model lifting body by direct numerical simulations under typical hypersonic conditions is investigated. The simulations analyze the model at three angles of sideslip: 0 degrees, 2 degrees, and 4 degrees. The freestream Mach number is 6, the unit Reynolds number is 1x10(-7)m(-1), with a fixed 2 degrees angle of attack. The result indicates that asymmetric transition occurs on the lifting body's surface between the sideslip windward and leeward sides, due to the side incoming flow. Five distinct transition regions are identified: the shoulder crossflow-vortex region, the shoulder vortex region, the lower surface vortex region, the lower surface crossflow region, and the top crossflow-vortex region. The shoulder crossflow-vortex region (windward) shows forward-shifting transition and expanding ranges as the angle of sideslip increases, with two different modes in the head of transition. The transition of the shoulder vortex region (leeward) moves forward and shifts spanwisely toward the attachment line; at the angle of sideslip of 4 degrees, the transition mode induced by the secondary instability of the stationary crossflow occurs. In the lower surface vortex region, transition moves forward, accompanied by localized turbulence spots and altered disturbance patterns at the high angle of sideslip. The lower surface crossflow-vortex (windward) region exhibits a transition region including two zones, while lower surface crossflow-vortex region (leeward) dissipates. The top crossflow-vortex region experiences intensified crossflow effects and localized turbulence spots as the angle of sideslip increases, with the appearance of the distinct topline similar to the attachment line

Research on High Sensitivity Wireless Pressure Sensor

为解决压力传感器在密闭空间、高旋、生物体内等不适用引线的问题,设计了一种无线压力传感器。对传感器进行原理分析及结构设计,采用MEMS工艺对硅片及; BF33进行加工,并搭建了谐振频率-压力测试平台,对传感器性能进行测试。压力测试范围为5 ~ 105 kPa,在常温时的灵敏度为161.5 Hz; /Pa,传感器具有较高的灵敏度,有利于提高压力检测精度。In order to solve the problem that the pressure sensor is not suitable; for the lead in the enclosed space and the living body,a wireless; pressure sensor was designed.The principle of the sensor was analyzed; and the structure was designed.The silicon and BF33 were processed by; MEMS process.The performance of the sensor was tested by the resonant; frequency pressure testing platform.The pressure test range is 5~ 105; kPa, the sensitivity is 161.5 Hz /Pa at room temperature, the sensor has; high sensitivity,which is helpful to improve the accuracy of pressure; measurement.航空科学基金资助项