Flocculation effect of Shinella sp. xn-1 on Microcystis aeruginosa

【目的】研究絮凝功能细菌xn-1对有害水华藻--铜绿微囊藻的絮凝效果,以期为有害水华的治理提供新的选择。【方法】采用涂布划线法从藻际分离纯化絮凝; 功能微生物;基于16S; rRNA基因序列确定进化地位;通过不同金属离子确定絮凝机制;梯度醇沉法获得絮凝物质;以酶标仪测定絮凝效率。【结果】菌株xn-1确定属于申氏杆菌属; (Shinella),且命名为Shinella sp.; xn-1。在添加Ca~(2+)作为促凝剂的条件下对铜绿微囊藻表现出高效的絮凝效果,其絮凝效果主要来源于胞外上清,而表现出高效的絮凝效果所需要的胞; 外上清添加量为3.0%。从胞外上清中获得的絮凝物质以0.5; g/L的添加量作用于藻细胞后表现出高效的絮凝效果,且随着处理时间增加,絮凝团的体积增大。【结论】Shinella sp.; xn-1通过分泌胞外絮凝物质对铜绿微囊藻表现出高效的絮凝效果,在絮凝作用下藻细胞聚集在一起形成大体积的絮凝团,该研究有利于治理有害水华。[Objective] To study the flocculation effect of bacterial strain xn-1 on; water bloom causing species-Microcystis aeruginosa, to control water; bloom. [Methods] Flocculation bacterium was isolated from phycosphere; based on plate spread and streak technique; 16S rRNA gene was applied to; determine the evolutionary status. Flocculation mechanism was confirmed; by addition of different metal ions as coagulants. Bioflocculant was; obtained by gradient alcohol precipitation. Microplate reader was used; to study flocculation activity. [Results] Strain xn-1 was determined as; a species of the genus Shinella, designated as Shinella sp. xn-1. Strain; xn-1 exhibited high flocculation activity on M. aeruginosa with adding; Ca~(2+) as coagulants, and the flocculation activity was originated from; extracellular supernatant, showing high flocculation efficiency with the; concentration of 3.0%. Bioflocculant isolated from extracellular; supernatant could exhibit high flocculation effect with the addition of; 0.5 g/L, and the algal flocs became huger with the increase of; processing time. [Conclusion] Shinella sp. xn-1 shows high flocculation; activity on M. aeruginosa through secreting extracellular bioflocculant,; and the flocs with large volume are formed under the flocculation; effect. This study is a useful option to control water blooms in the; future.国家自然科学基金项目; 河南师范大学博士科研启动基金项

近海生态系统碳汇过程、调控机制及增汇模式

海洋是地球上最大的碳库,发挥着全球气候变化缓冲器的作用.蓝色碳汇,简称蓝碳,即由海洋生态系统捕获的碳(主要是有机碳),是海洋储碳的重要机制之一.; 蓝碳最初认识的形式是可见的海岸带植物固碳.其实之前没有得到足够重视的、看不见的微型生物(浮游植物、细菌、古菌、病毒、原生动物)占海洋生物量90%; 以上,是蓝碳的主要贡献者.中国陆架边缘海占国土总面积的1/3,碳汇潜力巨大,亟待研发.本文以近海生态系统碳汇过程、调控机制及增汇模式为主线,论述; 了近海生态系统结构与碳循环功能特征、碳汇形成过程与机理,并结合近海碳汇在沉积记录中的地史过程演变探讨了自然过程和人类活动对碳汇的可能影响,展望了; 碳汇工程在增加近海海洋储碳能力方面的应用前景.国家重大科学研究计划项目; 国家重点研发计划项目; 国家自然科学基金项目; 国家海洋局全球变化与海气相互作用专项项

浦城县大口窑调查勘探报告

浦城县大口窑是宋元时期闽北地区一处著名的窑场,以烧造青白瓷为主,此外还兼烧部分酱釉瓷、少量绿釉瓷等。器型种类丰富,质量较高,窑业技术与江西景德镇窑关系密切。其产品在东亚、东南亚等地有发现,是福建一处重要的外销瓷生产地

1978～2008年中国湿地类型变化

分别基于美国陆地卫星(Landsat MSS/TM/ETM+)和中巴资源卫星(CBERS-02B)影像数据,以人工目视解译为主,完成了中国1978～2008年4期(基准年分别为1978,1990,2000和2008年)湿地遥感制图,并进行了大量的室内外验证.在此基础上,对我国湿地现状及近30年来湿地变化进行了初步分析,得到以下主要结论:(ⅰ)截止2008年,中国湿地面积约为324097km2,其中以内陆沼泽(35%)和湖泊湿地(26%)为主.(ⅱ)1978～2008年,中国湿地面积减少了约33%,而人工湿地增加了约122%.过去30年里湿地减少的速度大幅降低,由最初5523km2/a(1978～1990年)降为831km2/a(2000～2008年).(ⅲ)减少的自然湿地(包括滨海湿地和内陆湿地),其类型变化由湿地向非湿地转化的比例逐渐降低.初期(1978～1990年)几乎全部(98%)转换为非湿地;在1990～2000年间减少的自然湿地约有86%转化为非湿地,而在2000～2008年,这一比例下降为77%.(ⅳ)气候变化和农业活动是中国湿地变化的主要驱动因素,湿地变化在中国分为三大不同特征区域,即西部三省/自治区(西藏、新疆和青海)、北部两省/自治区(黑龙江和内蒙古)和其他省市区.其中西部区域尤其是青藏高原,湿地变化的驱动因子以气候增温为主;新疆湿地由于气候增温和农业活动共同作用造成变化不大.北部省/自治区的湿地变化则主要由农业活动引起;而其他省市区的湿地变化几乎完全受控于人类的农业经济活动

Space-time correlations of fluctuating velocities in turbulent shear flows

Space-time correlations or Eulerian two-point two-time correlations of fluctuating velocities are analytically and numerically investigated in turbulent shear flows. An elliptic model for the space-time correlations in the inertial range is developed from the similarity assumptions on the isocorrelation contours: they share a uniform preference direction and a constant aspect ratio. The similarity assumptions are justified using the Kolmogorov similarity hypotheses and verified using the direct numerical simulation DNS of turbulent channel flows. The model relates the space-time correlations to the space correlations via the convection and sweeping characteristic velocities. The analytical expressions for the convection and sweeping velocities are derived from the Navier-Stokes equations for homogeneous turbulent shear flows, where the convection velocity is represented by the mean velocity and the sweeping velocity is the sum of the random sweeping velocity and the shearinduced velocity. This suggests that unlike Taylor’s model where the convection velocity is dominating and Kraichnan and Tennekes’ model where the random sweeping velocity is dominating, the decorrelation time scales of the space-time correlations in turbulent shear flows are determined by the convection velocity, the random sweeping velocity, and the shear-induced velocity. This model predicts a universal form of the spacetime correlations with the two characteristic velocities. The DNS of turbulent channel flows supports the prediction: the correlation functions exhibit a fair good collapse, when plotted against the normalized space and time separations defined by the elliptic model

成果导向教学模式在电力机车驾驶课程中的实践研究

在成果导向教学理念的指导下，针对铁路运输行业对机车驾驶、机车运用与检修、保养与维护等高技能型人才的需求，以提高应用型人才培养质量为目标，机车驾驶专业与哈尔滨铁路局等企业合作成立机车“厂中校”，实现校企深度融合，打造成具有功能完善的“双主体”人才培养平台,努力培养铁路机务技能型专门人才。</jats:p

Prediction of Space-Time Correlations by Large Eddy Simulation

The recently increasing application of large eddy simulation to unsteady problems [1], such&nbsp;as turbulence-generated sound and turbulent reacting flows, requires that large-eddy simulation &nbsp; (LES) with a sub-grid scale (SGS) model could accurately predict space-time correlations. Most&nbsp;of the currently existing SGS models are based on the energy budget equations. Therefore, they&nbsp;are able to correctly predict energy spectra at large scales, but they may not accurately predict&nbsp;other statistical quantities that are not determined fully by large-scale energy spectra, such as&nbsp;space-time correlations. In this paper, we will investigate the effects of SGS modeling on space-time correlations in LES. The numerical simulations of isotropic turbulence [2, 3] and turbulence&nbsp;channel flows [4] show that, compared with the results of direct numerical simulation (DNS), LES under-predicts the un-normalized correlation magnitude and over-predict the decorrelation time scales. This can lead to inaccurate solutions in applications such as sound power spectra. In&nbsp;turbulence-generated sound, according to Lighthill&#39;s theory, the acoustic intensity radiated by&nbsp;turbulent flows depends on two-point, two-time correlations, or Eulerian space-time correlations. Therefore, an accurate calculation of the Eulerian space-time correlation is important to the prediction of the sound radiations. The application of space-time correlations to acoustic power&nbsp;in LES is also discussed. &nbsp

Three-dimensional reconstruction method for internal defect of alloy firmware

本发明涉及一种合金固件内部缺陷三维重建方法，包括以下步骤：利用无损检测设备生成红外图像；在红外图像中，通过无损检测技术对合金固件内部的缺陷进行无损检测，确定缺陷的位置范围及颜色差异信息；根据缺陷位置范围，结合传热学理论确定任意缺陷点的深度信息；根据缺陷的位置范围及深度信息，通过可视化技术，完成三维重建，实现缺陷的三维模拟。本发明可以将合金固件内部缺陷进行三维模拟，直观有效的呈现内部缺陷的三维影像，通过该方法可以探测到合金固件内部的缺陷情况，同时不损伤固件本身，方便技术人员可以多方位、多层次的对固件内部缺陷的三维影像进行详细观察，具有极其重要的实际意义和研究价值

Device and method for detecting length and motion directions of hitched ropes of underwater robots

本发明涉及一种水下机器人系缆长度及运动方向检测装置及方法，该装置安装于水下机器人的中继器中，具有从动轮，从动于系缆收/放机构中的大从动轮；两块永磁铁分别嵌设于从动轮的同心圆周上；两个磁力开关，与水下机器人的水下计算机相连，通过支架以非接触式分别设于从动轮同心圆周上方，两磁力开关通过永磁铁时产生脉冲的上升沿具有相位差，且两脉冲具有同时为高电平的时间段。该方法包括：水下计算机根据采集两脉冲的状态进行分析判断，得出从正转到反转和从反转到正转的不同的变化状态；判定系缆的实际运动方向，得出系缆长度脉冲的累加结果，进而得出系缆的长度。本发明结构简单、继承性好，定向可靠，计算准确，可适合于全海深检测

一种遥控水下机器人视频监控系统

本文介绍一种应用在遥控水下机器人上的视频传输与监控技术。采用光多路复用器实现水面与水下的数据及视频传输,通过工业以太网实现整个系统的摄像机及灯光控制,并对传输到水面视频信号进行显示、叠加及存储。该技术成功的应用在新开发的遥控水下机器人中,效果良好