21 research outputs found

    Recruitment of cyanobacteria from sediment of the Shanzai Reservoir

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    采用正交试验考察了温度、光照、营养盐和物理扰动4个因素对山仔水库冬季沉积物中蓝藻复苏的影响,每个因素设置两个水平,培养周期为6d,并以蓝藻复苏量为考察指标.结果表明,温度和光照为蓝藻复苏的主要影响因子,上覆水体的营养盐、物理扰动对沉积物中蓝藻门复苏的影响作用不显著,不同的蓝藻种属对温度和光照条件的响应程度不完全一致,蓝藻门微囊藻属(MICrOCySTIS)对温度和光照的复苏响应显著,颤藻属(OSCIllATOrIA)仅对温度的复苏响应显著.同时,通过设置6.0~16.0℃之间6个温度梯度及50和2000lX两个光照梯度,进行了沉积物柱状样复苏模拟实验.结果显示,山仔水库冬季沉积物微囊藻属和颤藻属在10℃左右开始复苏,微囊藻属对光的敏感性使其更容易处于优势地位.The effects of four environmental factors,including temperature,light,nutrient and physical disturbance,on the cyanobacteria recruitment from the winter sediment in the eutrophic Shanzai Reservoir were investigated using an orthogonal experiment.Two levels were designed for each factor and the experiments lasted for six days.The results showed that temperature and light were the most important for the recruitment of Microcystis and Oscillatoria.Increasing temperature would promote the recruitment of Microcystis and Oscillatoria which would make the cyanobacteria to dominate.The effects of the overlying water nutrient status and the physical disturbance on the recruitment of Microcystis and Oscillatoria from sediments were not obvious.Based on the results,different temperatures and light intensities were designed in the simulation experiment.The incubation temperatures were increased from 6.0 to 16.0 ℃ with six levels while each temperature level was kept for four days under 2000 and 50 lx light intensities,respectively.Recruitment was calculated by the diminution of benthic cyanobacteria abundance,and moreover,by the increase of cyanobacteria abundance in the water column.It is shown that the recruitment of Microcystis and Oscillatoria started at about 10 ℃.It was also demonstrated that the migration of Microcystis from the sediments was more pronounced at higher light intensity(2000 lx) than in dark(50 lx) treatments.国家自然科学基金项目(No.41101060);福建省自然科学基金(No.2010J01250);福建省教育厅科学研究基金(No.JA10085);厦门大学近海与海洋环境国家重点实验室青年学者访问基金项目(No.MELRS1103)---

    4.2度K下注NGaAlAs光荧光研究

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    一种微机械光开关的分析和设计(英文)

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    对悬臂梁微机械光开关的机电特性进行了理论分析。利用机械和电学特性,导出了悬臂梁的弯曲量和所加的电压的解析关系,并给出阈值电压的计算公式。指出外加电压与梁的宽度无关,与梁的长度的平方成反比。悬臂梁尖端的弯曲量不能超出相邻电极间距的1/3。这些结论是悬臂梁微机械光开关设计和研制的直接依据

    Si NIPI结构中光伏响应的极性及与浅杂质有关的光跃迁

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    对不同光照条件下Si NIPI结构的光伏效应进行了研究,并在正面光照时作了外加He-Ne激光连续照射前后的对比实验。结果表明, Si NIPI结构中存在Brum等预言的因光生载流子空间分离而产生的光伏效应,并且进一步从实验上证实了NIPI结构光伏极性是空间固定的。对外加激光连续照射前后结果的分析表明,Si NIPI结构的光伏效应中,实空间中的间接跃迁如电子空穴子带间跃迁不起主要作用,而主要取决于实空间中与浅杂质有关的直接或准直接跃迁

    微机电光开关

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    对微机械光开关的特点和应用作了简要的论述,并对近年国外几种典型微机械光开关的结构、原理和研制方法作了简要的介绍和评述。这类新型的开关器件的主要优点是串话小,插入损耗小、消光比高,对波长和偏振不敏感,且体积小,造价低等,在光纤通信和光纤测试系统中具有广阔的应用前景

    一种制备半导体固态白光光源的方法

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    本发明公开了一种制备半导体固态白光光源的方法,该方法包括:将激射波长位于蓝光的半导体激光器芯片烧结在热沉和基板上,并封装到管壳上;将荧光粉与固化剂混合,并在一定温度下固化在洁净的玻璃片上;利用半导体激光器光源激发固化后的荧光粉,使荧光粉产生白光。利用本发明所制备的白光光源具有较高能效、较高光通量和较高亮度;可单独对核心器件进行温控制冷,避免高温时器件和荧光粉发生退化;可制备出很小尺寸、具有特殊用途的白光光源

    ECR plasma CVD法淀积980 nm大功率半导体激光器端面光学膜技术

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    介绍了电子回旋共振等离子体化学气相沉积(简称ECR plasma CVD)法淀积980nm大功率半导体激光器两端面光学膜的工艺条件,探索了膜系监控的方法和优越性,讨论了这种淀积方法的优点和淀积的光学膜的优良特性

    一种制备微小化固态白光光源的方法

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    本发明公开了一种制备微小化固态白光光源的方法,该方法包括:将蓝光半导体激光器芯片烧结在热沉上,再将热沉烧结到散热基板上,再将散热基板固定在激光器管壳上;选用光纤棒作柱透镜,对激光器的快轴进行压缩,将压缩后的激光耦合进入光纤,靠近激光器一面的光纤棒和光纤端面均蒸镀增透膜,光纤的出光端面固定在陶瓷插针上;将黄色荧光粉与胶体按照一定比例混合均匀,将混合后的荧光粉和胶体固化在透明薄片上形成荧光粉片;从透明薄片上取下该荧光粉片,并将荧光粉片切成一定的形状,放入石英容器中。利用本发明,解决了如何将微小化的荧光粉片放在光纤端面附近,使其能被光纤出射的激光有效地激发
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