铜藻(Sargassum horneri)在营养限制胁迫后对NH4-N的超补偿吸收研究

以经济马尾藻铜藻(Sargassum horneri)为研究材料,研究了其在营养限制胁迫后对NH_4-N的超补偿吸收情况。实验分营养限制和恢复营养两个阶段进行,每个阶段均设置饥饿处理组、饱和处理组和正常对照组。铜藻在低营养限制胁迫(饥饿)下培养10天后,恢复营养盐培养3天,分别采用次溴酸盐氧化法和锌镉还原法测定培养液中的NH_4-N和NO_3-N的浓度。本文研究发现,饥饿处理组中铜藻吸收氨氮的速率远高于正常对照组和饱和处理组,在恢复培养第一天时,饥饿处理组对NH_4-N的吸收速率最高为14.94μmol/(g·h),与正常对照组及饱和处理组间差异显著。在恢复培养的后两天,三个处理组中铜藻对NH_4-N的吸收速率差异慢慢变小,直至最后几乎相同。三组对NO_3-N没有表现出较高的吸收,最高仅为6.15μmol/(g·h),结果表明:氮源包括NH_4-N和NO_3-N时,铜藻优先选择吸收NH_4-N。实验后称重测定生长速率:对照组、饥饿处理组和饱和组生长率(SGR)分别为8.48%、8.86%、8.01%,ANOVA方差分析表明,三者存在显著差异(P=0.0320.05),从而证实了铜藻也存在超补偿生长的现象。     

刘华一运用青蒿治疗脾胃病湿热证经验

介绍刘华一教授运用青蒿治疗脾胃病湿热证的经验。刘教授灵活运用青蒿治疗脾胃病中的湿热证，如运用青蒿配金铃子散治疗胃脘痛、运用青蒿加半夏泻心汤治疗痞满、运用青蒿加黄芩治疗便秘等，均取得良好的疗效。并附验案1则，以资佐证。     

Geochemical survey of thermal system in Northeast China and their geothermometric characters

The chemical composition of several thermal springs around Changbaishan area has been investigated. Cenozoic basaltic rocks are widely distributed in Northeast China and geothermal characteristics have been described. About one hundred hot springs exist around Changhaishan Volcano at the border between China and D.P.R.Korea with high temperature about 82~C. The pH values of the spring water range from 6.9 to 7.1 and the total flow rate is about 4.8 L/sec. The chemical composition of the thermal springs is sodium carbonate; the high-mineral contents of thermal water are believed to have medicinal properties. Bathhouses are already built along the hot springs to take the advantage of the supposed healing properties. The high quality of those hot springs is believed to be utilitized for mineral water. The chemical equilibrium temperatures were estimated at about 160℃ based on the Na-K-Ca geochemical thermometer.     

2003年河南各地土地市场秩序整顿成绩喜人

2003年2月以来,根据国务院和河南省政府的统一布署,全省各地广泛、深入地开展了土地市场秩序治理整顿工作,并取得了喜人的成绩。 请看: 在土地市场秩序治理中,该市几个月来重点抓了三件事:一是加大了对开发区和各类园区的整顿力度。该市现有各类园区7个,经过整顿,目前,已确认经国务院和部、省批准的4个予以保留;另须水工业园区和巩义工业示范区两个县级开发区由当地政府撤销,改建为办事处;另一处正在进一步规范中。二是对经营性土地招、拍、挂进行了规范。为此,该市制定了《郑州市国有土地使用权有偿使用条例》,且已经省人大常委会通…     

Does sediment grain size affect diatom grazing by harpacticoid copepods?

Estuarine soft sediments support a diverse group of eukaryotic and prokaryotic organisms though the role of the sediment per se for the functioning of these organisms remains largely unknown. The present study aimed to test the effect of sediment grain size on the grazing activities of harpacticoid copepods. In controlled experiments, two common intertidal harpacticoid species (Paramphiascella fulvofasciata and Nitokra spinipes) were each offered a mix of two benthic diatom species (Navicula phyllepta and Seminavis robusta) in different sedimentary conditions. Several microcosms were created using a variety of sediment types, including fine silt (<63 microm), coarser grained sands (125-250, 250-450, 100-300 microm), artificial 'sediments' of glass beads (250-500, 2000 microm) and even the absence of sediment was tested. The diatoms were enriched in the stable carbon (13)C to facilitate tracing in the harpacticoids. Both copepod species were able to graze on the diatoms with highest uptake when sediment was absent. In contrast, both harpacticoid species showed no uptake in silty conditions. In general, grazing was favoured when mean sediment grain size increased. The strong negative effect of fine grains on the grazer's efficiency can be explained by the resulting differences in the structure (and accessibility) of the diatom biofilm on the one hand and the mobility of the grazer on the other hand. In view of the subtle equilibrium between primary producers and grazers, these results might have important implications for the effect of siltation of tidal flats due to, e.g., human activities.