中国近海浮游细菌生物量与生产力的生态分布特点

本论文研究了胶洲湾、东海和渤海的蓝细菌（Synechococcus）、生物量、异养细菌生物量和生产力的生态学特点。并在汇泉湾、渤海和东海用分极增减法对海洋蓝细菌在微型食物环（the microbial loop）中的作用进行了初步研究。在以上海区调查研究的时间如下：胶州湾：1993年2月、5月、9月11月，1996年5月、1999年3月、5月和12月。汇泉湾：1996年4月至1998年4月。东海：1997年2-3月，1998年7月。渤海1998年9-10月，1999年4-5月。研究结果如下：胶州湾：蓝细菌生物量的变化范围是11.4-0.03 mgC/m~3，季节变化是夏季>秋季和春季>冬季。其水平分布是除夏季蓝细菌生物量是沿岸浅水区向湾外递减外，其它三季（春、秋和冬季）是由湾外向湾内至沿岸浅水区递减。蓝细菌生物量与海水温度周年变化正相关，与季节海水温度的关系是秋、冬季分布变化一致，春、夏季分布变化相反。海水温度是影响胶州湾蓝细菌生物量分布变化的主要原因。异养细菌生物量和生产力的变化范围分别是29.8-1.62 mgC/m~3; 129.12-1.92 mgC/m~3.d。季节变化都是夏季>秋季、春季>冬季。夏季的异养细菌生物量和生产力水平分布趋势与蓝细菌生物量的分布变化相同。海水温度对异养细菌生产力的影响较对异养细菌生物量的影响大。异养细菌生产力相比（BP:PP）的变化在0.58-0.02之间，季节分布变化是夏季>秋季、春季>冬季。夏季表层的BP:PP由沿岸浅水区向湾心、湾口和湾外递减。东海：蓝细菌生物量的变化范围是46.72-0.011 mgC/m~3，夏季高平均是23.59 mgC/m~3，冬季低平均是3.61 mgC/m~3。冬季蓝细菌生物量的水平分布明显受黑潮的影响，在表面和20米层是由东南向西北方向递减。其垂直分布是冬季表层和20米层>底层，夏季是20米层>表层>底层；在连续站冬111站和410站变化都是中层>底层>表层。异养细菌生物量和生产力的变化范围分别是17.2-4.4 mgC/m~3（1997.2）；376.8-7.2 mgC/m~3.d。异养细菌生产力夏季高平均是35.1 mgC/m~3.d。异养细菌生物量的水平分布是由沿岸向外海递增（1997.2），异养细菌生产力的水平分布是冬季异养细菌生产力在32度断面有由沿岸向外递减趋势，PN断面的变化与冬季相似。垂直分布，冬季和夏季的异养细菌生产力的垂直变化在2断面是底层大于表面，PN断面则是表层大于底层，32度断面大多断站是底层大于表层。在连续站冬季111站异养细菌生产力的变化是底层>中层>表层，409站的变化是中层>底层>表层，夏季111站和410站都是中>底层>表层。异养细菌生物量（1997.2）表层分布变化与海水温度分布变化相似，底层变化相反。异养细菌生产力与初级生产力相比（BP:PP），冬季在0.04-0.30之间，平均为0.17；夏季在0.20-0.43之间平均0.32。冬季在长江口附近BP：PP有一个高值区是0.30，夏季在111站附近有一个高值区是0.43。从连续站111站和409’站观测发现底层的BP：PP明显高于表层。渤海：蓝细菌生物量秋季（16.6-0.37 mgC/m~3）比春季（0.44-0.015 mgC/m~3）高。其秋季的水平分布与海水盐度水平分布相同，与海水温度水平分布相反。异养细菌生产力秋季（189-62.2 mgC/m~3.d）与春季（193.2-49.8 mgC/m~3.d）相当。但秋季捕层BP普遍小于底层，而春季是表层普遍大于底层。根据颗粒分级培养实验结果，海洋蓝图细菌在微型食物环中的作用如下：在汇泉湾的春季和秋季蓝细菌可能主要被小型浮游动物（microzooplankton 20-200 μm）捕食。在渤海的春季和秋季也是同样结果。但在东海夏季的111站和410站附近（东海大陆架中部）微型浮游动物（nanozooplankton 2-20 μm）对蓝细菌的捕食压力明显。

Typhoon effects on DOC dynamics in a phosphate-limited reservoir

To explore typhoon effects on dissolved organic carbon (DOC) dynamics, field investigations (tributary and dam site) and laboratory experiments (bioassay and DOC consumption) were conducted in a subtropical reservoir. A tributary survey indicated that after typhoon disruption, upstream areas were the sources of phosphate (P) but not DOC for the dam site located downstream. Bioassay experiments verified P-limitation on bacteria and phytoplankton during summer stratification, and bacteria showed a faster response than algae to added P. Experiments indicated that DOC consumption was determined by the availability of P. The 4 yr typhoon period (June-September) data of the dam site denoted that DOC concentration (27 to 270 mu M C) and its rate of change (-13 to 24 mu M C d(-1)) varied more dramatically in the weak (2006 and 2007) than in the strong (2004 and 2005) typhoon years. The negative correlation of DOC with the ratio of bacterial production (BP) to primary production (PP) in the euphotic zone (0 to 10 m) signified the interactive effects of auto- and heterotrophic processes on DOC variation. In the aphotic zone, the variation of DOC could be ascribed to the change of BP, which showed a positive correlation with P concentrations. This study documents that DOC concentration in the studied system varied at multiple time scales. Such variation can be explained by the decoupling between BP and PP, which is believed to be a function of the limiting nutrient's availability. More importantly, this study suggests that the P supply introduced by strong typhoons might have substantiated a tighter coupling between BP and PP, so that the amplitude of DOC oscillation during the summer period was effectively reduced.

贵州高原湖泊细菌分布及其制约因素与溶解有机质的关系

细菌不仅是水生生态系统中生物量的重要组成部分，而且在水生食物网的能量流动和生物地球化学循环（尤其是碳循环）中起着关键性作用。为了深入了解细菌在湖泊微生物环(Microbial loop)中的作用及其对碳循环的影响，我们利用SYBR Green I染色的荧光显微镜计数法，研究了阿哈湖和百花湖的细菌垂直分布以及环境因素和病毒对细菌丰度分布的影响，探讨了细菌及其影响因素与溶解有机碳(DOC)的相互关系。初步得出了以下几点认识： 1．SYBR Green I染色计数阿哈湖和百花湖细菌丰度变化范围的结果为(3.32~16.60)×106个.ml-1，平均值为百花湖(BH)＞阿哈湖入湖区(AHB)＞阿哈湖湖心区(AHA)，两湖细菌由湖水表层至底层大体上呈减少趋势。 2．两湖DOC的浓度范围为1.48~2.96 mg.L-1，病毒丰度变化范围为(1.87~12.50)×107个.ml-1，病毒丰度与细菌丰度的比值VBR变化范围为4.09~12.77，原生动物的丰度变化范围为18.79~53.86个.ml-1，类蛭弧菌的丰度变化范围为0.00~1.30个.ml-1，且均为百花湖＞阿哈湖入湖区＞阿哈湖湖心区。 3．pearson相关系数分析结果显示，阿哈湖和百花湖中细菌丰度与温度、pH、DO呈显著正相关，与电导率呈显著负相关，与病毒丰度呈极显著正相关，与原生动物丰度和类蛭弧菌丰度没有相关性。表明两湖中细菌丰度不但受温度调节，还与pH、DO和电导率这些环境因子关系密切。根据有限的数据，两湖的三类捕食者中，病毒的丰度大于原生动物和类蛭弧菌的丰度。 4．阿哈湖中细菌丰度与DOC呈极显著性正相关，而百花湖中细菌丰度与DOC无相关性。阿哈湖和百花湖中DOC均与DO呈极显著正相关，与pH呈显著正相关。这表明与细菌丰度关系密切的环境因素亦与DOC密切相关。在阿哈湖湖心区，病毒丰度与DOC有呈显著正相关，在阿哈湖入湖区和百花湖中，病毒丰度与DOC没有相关性。在阿哈湖入湖区虽然DOC与病毒丰度没有相关性，但DOC与VBR呈极显著性负相关。

Flow pattern in chandler loop - the artificial thrombus formation

In this paper a hydrodynamic approach is used to analyse carefully the flow field inChandler loop--the artificial thrombus formation. The results obtained show that near thelower meniscus where the thrombus is formed, there is a back flow accompanied with asecondary flow and its mainflow is toward the meniscus, thus providing a favourable condi-tion for corpuscle aggregation. Our finding is valuable for studying the mechanism ofthrombus formation in artificial organ and in vivo.

Phase-sensitive atom localization in a loop Lambda-system

The behaviour of the Lambda-system has been studied theoretically in the context of atom localization. In addition to the probe field and the standing wave driving field, a microwave field is introduced to couple the two lower states, and as a result our Lambda-system forms a closed loop. Therefore phase-sensitive atom localization is expected. Indeed by appropriate choice of the relative phase between three fields, an improvement by a factor of 2 has been found in the detection probability of atoms within the sub-wavelength domain of the standing wave. The effect of other parameters is also investigated.