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601.
Cysts of the planktonic oligotrich ciliate Strombidium conicum were isolated from sediment samples, collected monthly in Onagawa Bay on the northeastern Pacific coast of Japan, and incubated
under laboratory conditions of 20 °C in light. The excystment ability changed seasonally in a regular manner, which was demonstrated
by alternation of three characteristic seasonal patterns of the cumulative excystment curve, i.e., rapid, delayed and transitional
patterns. While the transitional excystment pattern was characteristic during the period from spring to midsummer, the rapid
pattern occurred during late summer to early winter. The pattern changed again to transitional in midwinter and finally returned
to the delayed pattern in late winter or early spring. We suggest that mud temperature was the most determinative factor of
this seasonality in excystment ability. Such synchronization of annual excystment helps this species to proliferate rapidly
and maintain the vegetative part of the population in the upper water column for a longer period of time where it is subjected
to the dispersion process due to water movement.
Received: 17 September 1996 / Accepted: 18 November 1996 相似文献
602.
矿井安全作业采用的填充密闭材料──泡沫树脂及其应用技术 总被引:8,自引:1,他引:7
泡沫树脂是一种新型安全填充密闭材料。以德国Isoschaum 型速凝泡沫树脂为例,分析与探讨了泡沫树脂材料的基本配方、性能、应用方法和应用范围以及我国在此领域的研究动向等问题。通过分析与研究发现,泡沫树脂具有良好的弹性、较低的透气性、不延燃、使用简便、可靠等优良特性,因此,建议我国矿山开采业尽快开发和应用这种新型安全填充密封材料 相似文献
603.
滚动轴承是设备中的易损件。介绍了鉴定滚动轴承损坏程度的快速鉴定方法,以决定是否更换轴承,从而降低了检修费用。 相似文献
604.
介绍了研制屋顶电除尘器要解决的几个问题。确定原始设计参数的方法,及其结构特点、技术指标。同时对运行状况作了简要分析。 相似文献
605.
606.
ABSTRACT: The study of wind generated waves is important because waves affect sediment resuspension in lakes. Measurements of wind velocity and wave elevation were made at three different stations in Lake Okeechobee. Significant wave heights were computed using a direct count from the recorded data, and verified by the root-mean-square value approach. The correlation between wind stress and significant wave height also was analyzed. The data revealed a strong correlation. In addition to field measurements, a Boussinesq-type wind-wave model was developed to simulate wind-generated, long-propagating waves. This model included the effects of wind stress and bottom viscous dissipation. Wave elevation and velocity field were evaluated numerically. A six-day simulation using 1996 wind data was conducted. Simulated significant wave heights were found to agree reasonably well with measured values. A predictive wind-wave model provides information about wind generated waves, which is used to compute bottom shear stresses required for sediment resuspension studies. 相似文献
607.
608.
化学修饰电极在环境微量及痕量有机物分析中的应用 总被引:1,自引:0,他引:1
根据实验研究及国内外文献,从伏安及电位溶出分析,流动注射/液相色谱电化学检测,化学修饰电极生物传感器及化学修饰电极预富集—石墨炉原子吸收法联用等方面,重点综述了化学修饰电极在环境微量及痕量有机物分析中的应用。 相似文献
609.
610.
We present an in-depth decompositionanalysis using physical indicators oftrends in Carbon dioxide (CO2) emissions in the cementindustry in Brazil, China, South Korea andthe United States. Physical indicatorsallow a detailed analysis of intra-sectoraltrends, in contrast to the often usedmonetary indicators. We assess thecontribution of different factors affectingCO2 emissions in the cement industry,including change in product mix, efficiencyof power generation, changes in fuel mixand changes in energy efficiency. Thedecomposition results show that in allexamined countries, increased productionwas the main contributor to the increase intotal CO2 emissions. Energy-efficiencyimprovement is the most important factorthat led to the reduction of emissionintensities for all countries except Korea.For Korea, structural change in the productmix is the most important factorcontributing to the emission intensityreduction. 相似文献