32 research outputs found

    高校仪器设备维修管理初探

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    文章对高校仪器设备维修管理中存在的问题进行了分析,并从加强仪器使用管理、加强仪器保养、建立维修团队、建立完善的维修制度及维修计划等方面提出了完善仪器维修管理的措施

    Experience in constructing the marine environment science national experimental teaching demonstration centre

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    结合建设国家级实验教学示范中心的经验,介绍了海洋环境科学实验教学中心改革与建设的思路、措施、成效和示范辐射作用,旨在加快实验教学改革和实验室建设,促进优质资源整合和共享,培养有创新精神和实践能力的高素质海洋环境科学人才。Based on the experience in constructing the national experimental teaching demonstration centre of marine environment,Xiamen University,elaborated on the guidelines,measures,objectives,the demonstration and radiating role,aiming to in speed up the step of experimental teaching reform and construction of laboratory,promote the superior resources integration and sharing,and cultivate the innovation spirit and the practice ability of the high-quality marine environmental science personnel

    Abundance and production of bacteria and their correlations with environmental factor

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    以2014年8月南海北部海水样品为研究对象,利用平板计数法和流式细胞仪计数法对南海北部表层和垂直海域可培养细菌和细菌总数分布状况进行研究,对细菌; 生产力进行测定,并结合环境因子进行相关性分析。结果表明:珠江口到南海北部海域,水平方向可培养细菌总数变化范围是3.70*10~2 ~; 1.42*10~3 CFU/mL,细菌总数变化范围是5.12 * 10~5 ~1.61 * 10~6; cells/mL,细菌生产力的变化范围是0.03 ~0.40 mg/m~3/h;垂直方向上可培养细菌变化范围是1.08 *10~3 ~9.00; *10~3 CFU/mL,细菌生产力变化范围是0.01 ~0.08; mg/m~3/h,其中表层海水中的细菌生产力明显高于底层。与环境因子相关性分析表明,水平方向上,影响南海北部表层海水细菌总数和细菌生产力的主要因; 素是温度、盐度、硝酸盐(NO_3-N)、硅酸盐(SiO_3-Si)、亚硝酸盐(NO_2-N)和磷酸盐(PO_4-P)(P<0.05);垂直方向上; ,影响南海北部可培养细菌总数的主要因素是NO_2-N(P<0.05),影响细菌生产力的主要影响因素是温度和盐度(P; <0.05)。可见,南海北部表层海水中细菌总数高于可培养细菌总数2; ~3个数量级,表明该海域表层海水存在大量不可培养细菌;细菌的生命活动在海水表层相较底层更为活跃。Distribution of abundance and production of bacteria and their; correlations with environmental factor were investigated, using plate; count method and flow cytometry, in the surface and vertical waters of; the northern south China sea in August 2014. The cultivable bacterial; abundance ranged from 3.70 * 10~2 CFU/mL to 1.42 * 10~3 CFU/ mL, the; total bacterial abundance ranged from 5.12 * 10~5 cells/mL to 1.61 *; 10~6 cells/mL and the bacterial productions varied from 0.03 mg/m~3/h to; 0.40 mg/m~3/h in horizontal distribution. In vertical distribution, the; cultivable bacterial abundance ranged from 1.08 * 10~3 CFU/mL to 9.00 *; 10~3 CFU/mL and the bacterial productions varied from 0.01 mg/m~3/h to; 0.08 mg/m~3/h, respectively. The correlation analysis results showed; that the environmental factors affecting the abundance of total bacteria; and bacterial productivity included temperature, salinity,; nitrate(NO_3-N),silicate (SiO_3-Si), nitrite (NO_2-N),and phosphate; (PO_4-P) (P<0.05). NO_2-N was the main influencing factor to cultivable; bacteria abundance (P < 0.05), while bacterial productivity was highly; correlated with temperature and salinity in vertical distribution of; northern south China sea (P < 0.05). The total bacterial abundance was 2; ~ 3 orders of magnitude higher than cultivable bacteria, suggesting that; there were many uncultured bacterium in surface water of northern south; China sea and bacterial activities in the surface maybe more active than; in the bottom.全球变化与海气交互作用; 国家重点研发计划全球变化及应对专项; 海洋公益性行业科研专

    Diversity of CO_2 fixation gene in the surface waters of northern South China Sea in the Calvin cycle

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    为揭示南海北部表层海水中参与卡尔文循环的固碳基因多样性及其与环境因子的关系,本研究以卡尔文循环中的关键酶核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubis CO)的Ⅰ、Ⅱ型基因(cbbL、cbbM)作为分子标记,采用Illumina Miseq高通量测序技术对海水中的固碳基因多样性进行分析,并结合多元统计分析的方法,探讨了固碳基因多样性与环境因子的关系.结果显示,在南海北部表层海水中,含cbbL基因固碳基因主要归属于变形菌门(Proteobacteria)、蓝藻门(Cyanobacteria)和厚壁菌门(Firmicutes),其中,优势亚群分别是γ-变形菌亚门(45.3%)、蓝细菌(30.9%)和β-变形杆菌亚门(23.8%);而含cbbM基因的固碳菌群未检测到;近岸的A9站位与其他站位物种组成有一定的差异,异着色菌属(Allochromatium)、硫杆菌属(Thiobacillus)和硫单胞菌属(Thiohalomonas)为其特有菌属.相关性和冗余分析(RDA)结果显示,含cbbL基因的固碳基因丰度与水温、盐度呈显著负相关(p<0.01),与硝酸盐、亚硝酸盐、硅酸盐呈显著正相关(p<0.01).To elucidate the diversity of CO_2 fixation and its relationship with environmental factors in surface water of northern South China Sea,the coding gene form I( cbbL) and form II( cbbM)( that encodes Ribulose-1,5-biphosphate carboxylase/oxygenase( Rubis CO) were chosen as biomarkers in Calvin-Benson-Bassham cycle( a common carbon fixation pathway for chemolithoautotrophic microorganisms) to analyze the carbon sequestration gene diversity. The Illumina Miseq sequencing method and multivariate statistical analysis were employed. The cbbM gene was not detected in any of samples,while the cbbL gene was found in all samples. The cbbL-containing genetic communities were dominated by Proteobacteria,Cyanobacteria and Firmicutes,in which γ-Proteobacteria( 45. 3%),Cyanobacteria( 30. 9%),β-Proteobacteria( 23. 8%) were predominant subpopulation. There were differences between the nearshore station of A9 with other stations,in which Allochromatiu,Thiobacillus and Thiohalomonas were unique species in A9 station.Relativity and redundancy analysis suggest that water temperature, salinity, nitrate, nitrite, silicate were highly statistically significant factors.Temperature and salinity were positively( p < 0. 01),while the other three factors negatively influenced CO_2 fixation gene of cbbL gene abundance( p <0. 01).全球变化与海气交互作用专项(No.GASI-03-01-02-05);; 海洋公益性行业科研专项(No.201305030,201405007)~

    基于集成学习的空间科学卫星工作模式识别

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    针对空间科学卫星遥测参数数据量大且特征维度高、需要消耗大量人力资源预先设置海量阈值、预先设置的阈值可能不再适用、现有监测手段可扩展性低等问题,提出了一种基于集成学习的空间科学卫星工作模式识别方法。该方法采用相关系数统计特性和互信息理论对遥测参数数据进行筛选降维,使用数据重采样技术解决数据集中存在的类别不平衡问题,构建集成学习模型,实现空间科学卫星工作模式的识别。借助某型号科学卫星真实遥测参数数据对该方法进行验证,在短时内便可构建完成算法模型,模型对整体类别的识别正确率高达99.67%,可正确识别多数类样本和少数类样本,为地面运控人员判断空间科学卫星工作模式提供了决策依据

    FEBIAD离子源的新进展

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    描述了用于兰州在线同位素分离的FEBIAD靶 -离子源的改进、最新进展和结果。经过改进后 ,在线同位素分离器对Xe的分辨本领由原来的 360提高到 60 0 ,对199Hg的在线测量效率提高了一个数量级 ,并测出了Hg、At、Rn等元素的一系列放射性同位素产物及生成截面为 5×10 - 34 m2 的2 0 8Hg衰变的能量最高的一条γ线

    熔化靶技术用于在线同位素分离器

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    将熔化铅靶技术应用于在线同位素分离器。 6 0 0MeV中能18O束轰击熔化铅靶的反应产物通过传输管扩散进入离子源 ,由带传输系统进行汞同位素的收集和传输。实验观测到了汞的若干同位素的γ射线
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