Succession of the Nanoplankton Community during a Brown Tide in a Scallop Culture Area in China     

Qiao  Ling  Yu  Jie  Li  Ying  Guo  Haobing  Zhen  Yu  Zhang  Lingling  Mi  Tiezhu  Zhang  Fuchong  Bao  Zhenmin 《Ocean Science Journal》2019,54(3):375-392

Ocean Science Journal - Brown tides caused by Aureococcus anophagefferens have occurred frequently in the coastal waters of Qinhuangdao since 2009. The Changli coast is the area most strongly...  相似文献   

火星陨石NWA 8716的岩矿学特征及粗粒橄榄石斑晶的来源     

吴蕴华  邓志培  梅苞  徐伟彪 《天文学报》2019,60(4):120-132

火星陨石可以为研究火星岩浆演化过程提供直接证据并限制其源区特征.通常认为含粗粒橄榄石斑晶辉玻无球粒陨石携带有火星原始地幔的信息,因此选取该类样品Northwest Africa (NWA) 8716为研究对象,进行岩相结构及矿物成分分析. NWA8716由橄榄石、辉石、填隙状熔长石以及其他次要矿物组成.其中橄榄石颗粒有两种级别的粒径,长轴分别约为0.5–1.8 mm和50–400μm.较小橄榄石斑晶内部的熔体包裹体和NWA 8716全岩成分(计算值)均显示明显的轻稀土元素亏损([La/Yb]CI值为0.06–0.1),说明NWA 8716源于一个亏损的火星岩浆池.粗粒橄榄石斑晶的来源对衡量该样品是否能够代表原始熔体成分非常重要.对橄榄石晶体的粒径统计分析发现,粗粒橄榄石斑晶应为堆晶.进一步对铁-镁以及稀土元素分配特征的计算表明NWA 8716并非形成于一个封闭系统,但是计算所得原始熔体成分与全岩成分差异不大,因此粗粒橄榄石斑晶应当来源于与母岩浆成分相似的熔体.总的看来, NWA 8716应当来源于亏损型火星幔源区且演化程度较低.  相似文献   

基于水利益共享的跨境流域水资源多目标分配研究——以澜沧江-湄公河为例   总被引：2，自引：1，他引：1  

刘艳丽  赵志轩  孙周亮  王国庆  金君良  王高旭  鲍振鑫  刘翠善  贺瑞敏 《地理科学》2019,39(3):387-393

以水利益共享代替分水的理念有利于充分发挥水资源效益和减少区域矛盾冲突,但由于缺乏具体可实施的分配模式一直停留在设想阶段。基于水利益共享理念,建立跨境流域水资源多目标分配指标体系,并结合澜沧江-湄公河流域跨境水资源利用现状及需求,提出澜沧江-湄公河流域跨境水资源多目标分配模型。为基于水利益共享的跨境水资源多目标分配提供了具有充分可操作性的指标体系和分配模型,有助于推进跨境流域水利益共享的实施,实现区域双边或多边在水资源利用上的共赢和发展目标。  相似文献   

13世纪以来中国海洋盐业动态演变及驱动因素     

鲍俊林  高抒 《地理科学》2019,39(4):596-605

海洋盐业是中国海洋经济的重要部分,也是沿海传统产业之一,13世纪以来不断发展演变。将沿海分为北、东、南3个地带,搜集整理与海盐经济相关的多种历史文献及方志资料,运用地理学方法分析评估了海洋盐业百年尺度的动态演化过程,并比较了资源环境与管理政策的驱动作用及其差异。研究表明：① 沿海盐业表现为传统煎法长期主导、逐步废煎改晒的过程,不同盐区的演化进程存在显著差异,北部盐区最快,东部次之,南部整体发展缓慢;② 海盐生产重心长期位于东部的两淮盐区,19世纪后期向北部盐区快速迁移;③ 资源环境与生态差异促进了各岸段海盐生产演化分异,垄断性管理政策迟滞了海洋盐业的空间集聚进程,未来沿海开发与海洋盐业的可持续发展将主要依靠基于资源生态约束的管理政策与技术。  相似文献   

养殖裙带菜机械损伤防御应答的初步研究     

任兰英  崔相东  刘岩  宫庆礼 《海洋湖沼通报》2019,(4):133-139

以裙带菜(Undariapinnatifida(Harv.)Suringar)幼孢子体为材料,测定藻体对机械损伤的防御应答。结果显示:与对照组相比,机械损伤会诱导藻体内活性氧含量上升,以及抗氧化酶活性和抗氧化物含量的变化。当裙带菜受到机械损伤后,体内O2-和H2O2以及MDA等物质迅速积累,藻体的总抗氧化能力上升、CAT和POD活性在短时间内迅速升高、GSH和ASA迅速合成,从而在较短时间内控制活性氧以及MDA含量;与对照组相比,SOD活性仅在3h内高于对照组。该实验结果表明裙带菜幼孢子遭受机械损伤后的抗氧化系统会参与调节机体活性氧平衡,这种抗氧化机制的存在可以更快速、更节能、更有效地修复藻体所受损伤。  相似文献   

珠江口盆地珠三坳陷文昌组有机质碳同位素异常成因     

何智同  尹相东  陈世加  雷明珠  朱必清  刘杨  赵荣茜  刘宇阳 《地质学报》2024,98(1):266-279

部分中国近海湖盆和大西洋裂谷盆地发现了腐泥型有机质碳同位素偏重的现象,并伴随异常高总有机碳含量和生烃潜力。本文依据泥岩有机碳测试、孢粉分析、主微量元素、泥岩和原油碳同位素及饱和烃色质色谱资料,并结合现代湖泊盘星藻发育特征,从有机质来源、古环境条件和有机质保存改造三个方面探讨了珠江口盆地珠三坳陷古近系文昌组碳同位素正偏移的成因机制。珠三坳陷文昌组碳同位素异常与气候、古生产力、古水深和藻类勃发等古环境因素有关。然而,从三级层序尺度看,古水深可能是一个不可忽视的重要因素：指示水深的Rb/K比值随深度加深而增加,与碳同位素和TOC含量变化趋势一致。同时现代湖泊研究也证实了盘星藻分布于不同水深范围,因此“深水型盘星藻”的繁盛很可能是珠三坳陷文昌组二段烃源岩碳同位素偏重的根本原因。  相似文献   

华南石炭纪中期白云岩地层分布及其形成模式     

宋英凡  王向东  李莹  史宇坤  胡科毅  黄兴  盛青怡  要乐 《地质学报》2024,98(2):346-362

石炭纪是地质演化历史上重要的时期,发生了全球规模的海西造山运动,晚古生代大冰期（LPIA）达到峰值,全球海平面频繁波动,导致古气候和古环境的剧烈变化。在华南,石炭纪中期,浅水碳酸盐岩台地相区广泛发育一套白云岩沉积。本文系统总结华南3个主要碳酸盐台地内白云岩的厚度及时代,识别出白云岩时空分布的差异性。结合石炭纪中期全球气候环境特征,认为冰期兴盛引发了全球海平面下降,导致华南各沉积盆地形成利于白云岩化的环境,白云岩得以发育。而白云岩时空分布的差异性可能与各沉积盆地独特的构造演化以及不同成岩模式有关。中下扬子碳酸盐岩台地白云岩的形成模式主要为萨勃哈模式和成岩早期浅埋藏的渗透回流模式,形成相对较薄的白云岩沉积;中南部和西南部碳酸盐岩台地白云岩的形成模式为渗透回流模式,成岩规模较大,沉积较厚。  相似文献   

Impacts of soil fauna on litter decomposition at different succession stages of wetland in Sanjiang Plain, China   总被引：1，自引：0，他引：1  

Haitao Wu  Xianguo Lu  Ming Jiang  Xiao Bao 《中国地理科学(英文版)》2009,19(3):258-264

Litter decomposition is the key process in nutrient recycling and energy flow. The present study examined the impacts of soil fauna on decomposition rates and nutrient fluxes at three succession stages of wetland in the Sanjiang Plain, China using different mesh litterbags. The results show that in each succession stage of wetland, soil fauna can obviously increase litter decomposition rates. The average contribution of whole soil fauna to litter mass loss was 35.35%. The more complex the soil fauna group, the more significant the role of soil fauna. The average loss of three types of litter in the 4mm mesh litterbags was 0.3–4.1 times that in 0.058mm ones. The decomposition function of soil fauna to litter mass changed with the wetland succession. The average contribution of soil fauna to litter loss firstly decreased from 34.96% (Carex lasiocapa) to 32.94% (Carex meyeriana), then increased to 38.16% (Calamagrostics angustifolia). The contributions of soil fauna to litter decomposition rates vary according to the litter substrata, soil fauna communities and seasons. Significant effects were respectively found in August and July on C. angustifolia and C. lasiocapa, while in June and August on C. meyeriana. Total carbon (TC), total nitrogen (TN) and total phosphorus (TP) contents and the C/N and C/P ratios of decaying litter can be influenced by soil fauna. At different wetland succession stages, the effects of soil fauna on nutrient elements also differ greatly, which shows the significant difference of influencing element types and degrees. Soil fauna communities strongly influenced the TC and TP concentrations of C. meyeriana litter, and TP content of C. lasiocapa. Our results indicate that soil fauna have important effects on litter decomposition and this influence will vary with the wetland succession and seasonal variation. Foundation item: Under the auspices of State Key Development Program for Basic Research of China (No. 2009CB421103), Key Program of National Natural Science Foundation of China (No. 40830535/D0101), Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-BR-16, KSCX2-YW-N-46-06)  相似文献   

Methods Comparison for Microsatellite Marker Development： Different Isolation Methods, Different Yield Efficiency     

Aibin Zhan  Zhenmin Bao  Xiaoli Hu  Wei Lu  Jingjie Hu 《中国海洋大学学报(英文版)》2009,8(2):161-165

Microsatellite markers have become one kind of the most important molecular tools used in various researches. A large number of microsatellite markers are required for the whole genome survey in the fields of molecular ecology, quantitative genetics and genomics. Therefore, it is extremely necessary to select several versatile, low-cost, efficient and time- and labor-saving methods to develop a large panel of microsatellite markers. In this study, we used Zhikong scallop (Chlamys farreri) as the target species to compare the efficiency of the five methods derived from three strategies for microsatellite marker development. The results showed that the strategy of constructing small insert genomic DNA library resulted in poor efficiency, while the microsatellite-enriched strategy highly improved the isolation efficiency. Although the mining public database strategy is time- and cost-saving, it is difficult to obtain a large number of microsatellite markers, mainly due to the limited sequence data of non-model species deposited in public databases. Based on the results in this study, we recommend two methods, microsatellite-enriched library construction method and FIASCO-colony hybridization method, for large-scale microsatellite marker development. Both methods were derived from the mi-crosatellite-enriched strategy. The experimental results obtained from Zhikong scallop also provide the reference for microsatellite marker development in other species with large genomes.  相似文献   

雄性半滑舌鳎雄激素受体基因的克隆与表达分析     

温海深  张葭人  陈彩芳  金国雄  陈晓燕  史宝  何峰 《中国海洋大学学报(自然科学版)》2009,39(3)

利用RT-PCR方法从半滑舌鳎(Cynoglossus semilaevis)中克隆了雄激素受体(Androgen receptor,AR)基因cDNA的部分序列(434 bp),经BLAST比对与狼鲈(Dicentrarchus labrax)、花溪(Kryptolebias marmoratus)、三斑海猪鱼(Halichoeres trimaculatus)和三刺鱼(Gasterosteus aculeatus)的雄激素受体同源性分别为84%,82%,82%和81%.组织表达分析表明,AR基因在半滑舌鳎的性腺、肝、胃、脾、肾、头肾、肠、鳃、心、脑和肌肉这11种组织中均有表达,表达量有所差异.肾中表达量最丰富,鳃中最少.根据其他硬骨鱼类表达模式,推测半滑舌鳎可能只含有1种AR.  相似文献