褐藻多酚的毒理学研究

目目前前的的研研究究普普遍遍认认为为 ,,人人体体老老化化导导致致癌癌症症、、心心脏脏病病、、脑脑中中风风等等疾疾病病主主要要是是由由于于自自由由基基未未能能得得到到有有效效清清除除造造成成的的。。因因此此 ,,如如果果食食物物中中含含有有丰丰富富的的抗抗氧氧化化物物质质 ,,就就具具有有益益寿寿延延年年的的作作用用 ,,在在某某种种程程度度上上 ,,可可以以将将现现代代抗抗氧氧化化与与抗抗自自由由基基理理论论看看作作““药药食食同同源源””的的分分子子水水平平解解释释。。植植物物含含有有丰丰富富的的自自由由…     

Seasonal change of ice algal and phytoplankton assemblages in the Nella Fjord near Zhongshan Station, East Antarctica

The ice algal and phytoplankton assemblages were studied from Nella Fjord near Zhongshan Station, East Antarctica from April 12 to December 30, 1992. Algal blooms occurred about 3 cm thick on the bottom of sea ice in late April and mid November to early December respectively, and a phytoplankton bloom appeared in the underlying surface water in mid December following the spring ice algal bloom. The biomass in ice bottom was 1 to 3 orders of magnitude higher than that of surface water. Amphiprora kjellmanii, Berkeleya sp., Navicula glaciei, Nitzschia barkelyi, N. cylindrus /N. curta, N. lecointei and Nitzschia sp. were common in the sea ice temporarily or throughout the study period. The biomass in a certain ice segment was decreased gradually and the dominant species were usually succeeded as the season went on. Nitzschia sublineata and Dactyliosolen antarctica were two seasonal dominant species only observed in underlying water column. The assemblages between bottom of ice and underlying surface water were different except when spring ice algae bloomed. The evidence shows that the ice algal blooms occurred mainly by in situ growth of ice algae, and the phytoplankton bloom was mostly caused by the release of ice algae.     

Pigment characterization for the 2011 bloom in Qinhuangdao implicated "brown tide" events in China

A large-scale bloom occurred from May to June in 2011 in sea area near Qinhuangdao of the Bohai Sea, leading to huge damage of the scallop culture industry. Similar blooms have been observed in this region for three years. The causative species of the bloom, which dominated the phytoplankton community with the maximum cell density around 109 cell/L, could not be identified with morphological features due to the small cell size (~2 mm). A pigment analytical method was then adopted to analyze the pigment profile of the phytoplankton samples collected from the blooming sea area. It was found that pico-sized (<2 mm), nano-sized (2-20 mm), and bulk phytoplankton samples had similar pigment profile, representing the pigment signature of the bloom-causative species. The major pigments detected included 19-butanoyloxyfucoxanthin (But-fuco), fucoxanthin (Fuco), diadinoxanthin (Diad) and chlorophyll a (Chl a), and high content of But-fuco was the most significant characteristics of the phytoplankton samples. Based on the pigment composition and content, the bloom-causative species could be tentatively identified as pelagophyte, "type 8" group of haptophyte, or silicoflagellate. Some unique features of the bloom, such as the extremely high cell density, small-sized and But-fuco containing cells, occurring in early summer, and the feeding-cessation effects on scallops, suggest it be a "brown tide" event similar to those reported in the east coast of the United States of America. The recurrent "brown tide" events and their dramatic impacts on the shellfish mariculture industry in Qinhuangdao need close attention in the coming years.     

有毒赤潮藻及其毒素的危害与检测

海洋中可引发赤潮的藻类约有300种,其中有毒赤潮藻为80种左右。现已知道的赤潮藻主要毒素有麻痹性贝毒、腹泻性贝毒、记忆缺失性贝毒、神经性贝毒、西加鱼度和溶血性毒素,前5种毒素的结构已经基本得到证实。有毒赤潮藻的毒素可以在海洋生物体内积累,人类误食含有藻毒素的食品时可能中毒,严重者还可能死亡。海洋有毒赤潮藻及其毒素的检测已经成为当今全球赤潮研究和监测的重要内容之一,可以通过形态学分类方法、分子生物学技术(遗传探针)和免疫学检测技术对有毒赤潮藻进行检测;可以通过生物学、物理化学检测方法和神经受体结合、免疫学检测技术对赤潮藻毒素进行检测。     

湘黔地区震旦纪菌藻硅质岩特征及形成机理探讨

湘黔地区震旦纪菌藻硅质岩化学成分纯净,硅质矿物含量95%以上,几乎都为泥晶—微晶石英,石英结晶度平均为6.35。岩石具菌藻生物结构,以纹层状构造为主。其中丰富的菌藻生物化石,按形态可划分为三种类型。岩石属原生沉积成因,二氧化硅的聚沉一方面通过菌藻有机体的硅化作用,另一方面是菌藻生物化学作用引起微环境变化而导致二氧化硅的聚沉。     

塔里木盆地柯坪地区上寒武统表生溶蚀型藻格架白云岩的地球化学特征及意义*

采用野外观察、室内薄片鉴定及多项地球化学分析技术方法,对塔里木盆地柯坪地区上寒武统表生溶蚀型藻格架白云岩的特征及成因进行了研究。宏观上,藻格架白云岩呈丘状、透镜状夹于潮坪相白云岩层间,由于差异性溶蚀,发育了大量表生溶蚀孔。微观上,藻格架由富藻的泥粉晶白云石组成,而架间孔由浅色的亮晶白云石充填。藻格架泥粉晶白云石呈他形—半自形,镶嵌结构,具有暗红色—橙红色的阴极发光,较高的Na、K含量,较低的Fe含量;δ¹³C为-0.572‰～0.124‰、平均值-0.116‰,δ¹⁸O为-5.391‰～-4.983‰、平均值-5.240‰,表明其形成于准同生阶段盐度较高的相对氧化环境中。架间充填的亮晶白云石胶结物,呈半自形—自形中细晶,具有昏暗的阴极发光或者不发光,较低的Na、K含量,较高的Fe含量,δ¹³C值为-0.662‰～-0.251‰、平均值为-0.460‰;δ¹⁸O值为-6.639‰～-5.939‰、平均值-6.267‰,表明其形成于相对还原的埋藏环境。稀土元素分析结果表明,二者均具有LREE轻微富集、HREE亏损、Eu负异常特征,与海相泥晶灰岩稀土元素配分模式相似,揭示了其白云化流体均来自于原始的海水。在溶蚀作用方面,亮晶白云石胶结物相对泥粉晶白云石藻格架更易于溶蚀。前者在大气水表生溶蚀过程中,主量元素Ca、Mg丢失显著,Mg/Ca值由0.955降至0.007,微量元素Na、K丢失相对明显,Na/Ca值由原来的3.8×10^-4降为1.9×10^-4,K/Ca值由1.1×10^-3降至检测限以下,而不改变稀土元素的配分模式。这些特征表明,表生溶蚀过程在元素特征上是一个去白云化的盐度降低过程,而这一过程中基本无稀土元素的带入带出。     

川中高石梯地区灯四段藻丘类型与沉积模式

四川盆地高石梯地区震旦系灯影组四段台缘带油气资源储量巨大,藻丘的发育是优质储层形成的基础,因此讨论四川盆地高石梯地区的藻丘类型与沉积模式就显得尤为重要.通过岩心观察、薄片鉴定并结合测井资料,详细阐述了高石梯地区灯四段的藻丘类型与沉积模式.研究结果表明:1)该地区岩石类型可分为富藻类云岩和贫藻类云岩:富藻类云岩是藻丘的丘...     

松花湖富营养化现状及其影响因素分析

通过2002年和2003年对东北地区松花湖水体富营养化状况进行调查和采样分析，对大量数据的多元相关分析和多元逐步回归分析、AGP试验和利用综合营养状态指数法进行评价。结果表明：松花湖处在中营养和轻度富营养状态；总磷是限制水体富营养化的主要因子之一。水体中变温层的形成，限制了上、下层湖水的混合，对下层水体中的溶解氧、无机氮和可溶性磷酸盐产生影响，随着变温层的消失，下层内的营养物质转移到湖上层，为藻类的繁殖提供条件。     

过去40年太湖剧烈的湖泊物理环境变化及其潜在生态环境意义

过去40年,全球气候变暖、辐射变暗和变亮、风速减弱、气候异常波动等自然环境变化以及筑坝建闸、岸堤硬质化和调水引流等强烈人类活动势必会深刻改变太湖湖泊物理环境和过程,驱动湖泊生态系统演化.基于历史文献、档案数据以及气象水文和透明度等长期观测数据,本文系统梳理了太湖气温、水温、风速、水位和透明度等物理环境空间分布和长期变化特征,探讨了气温和风速、水位和透明度相互协同作用机制及其潜在生态环境意义.受全球变化和城市化等影响,过去40年太湖气温和水温呈现显著升高趋势,而近地面风速则表现为持续下降,湖泊增温和风速下降有利于藻类生长和蓝藻水华漂浮聚集,某种程度上增加了蓝藻水华出现频次和集聚的面积.为防洪和满足流域日益增长的水资源需求,闸坝管控和调水引流使太湖水位呈现缓慢增加趋势,而入湖污染物增加和富营养化则造成水体透明度逐渐下降,致使透明度与水位(水深)的比值明显降低,减少了湖底可利用光强,恶化水下光环境,在一定程度上驱动了太湖水生植被和草型生态系统退化.湖泊物理环境长期变化逐渐拓展了太湖藻型生境空间而压缩了草型生境空间,加剧了草型生态系统向藻型生态系统转化和增强了藻型生态系统的自我长期维持.太湖湖泊物理环境的显著变化也会部分抵消流域营养盐削减和湖体营养盐下降对藻类生物量和蓝藻水华的控制,增加了太湖蓝藻水华防控和湖泊富营养化治理的难度.这意味着未来流域控源截污需要更加严格的标准,而湖泊水位等物理环境的有效管控是应对藻华加剧和恢复草型生态系统的适应性管理策略.     

广东省高州水库春季蓝藻水华成因初步探讨

高州水库为广东省茂名市重要的饮用水源地,2009年和2010年春季相继出现蓝藻水华,给居民饮水带来安全隐患.对高州水库2009年和2010年春季水华情况进行分析,结果表明:两年浮游藻类细胞密度最高分别达4.08×107 cel1s/L和1.47 x 108cells/L,其中蓝藻所占比例分别为98.2%和98.7%,优...