Spatial variability of summer and autumn phytoplankton community structure in Xiamen Western Bay based on pigment analysis   总被引：2，自引：0，他引：2  

HE Xueji  PENG Xingyue 《海洋学报(英文版)》2012,31(5):165-175

The spatial variations of phytoplankton community structure in the Xiamen Western Bay during the summer and autumn cruises in 2001 were investigated based on HPLC analysis of photosynthetic pigments in algal cells and CHEMTAX processing of pigment data.The Chl a concentration reached 18.9 μg/L in the summer and declined to 0.28-2.17 in the autumn,respectively,consistent with the observation of diatom blooms in June.Among the accessory pigments,fucoxanthin was consistently the most abundant,ranging from 0.172 to 8.46 μg/L,with the maximum concentrations in June.19'-hexfucoxanthin and alloxanthin were the other two abundant pigments in the summer and autumn.In addition,19'-butanoyloxyfucoxanthin or peridinin was also important in late autumn.Generally the biomass of all the phytoplankton or each group was higher in the inner part than the mouth of this bay,represented by Chl a.CHEMTAX processing revealed the dominance of diatoms with their contribution of 14.6%-52.5% to the total Chl a,but its importance decreased in the autumn.Cryptophytes and Haptophytes,with an average contribution of 16.9%-31.4% and 12.1%-26.3%,were the other two important groups,especially in the autumn.On the contrary,Dinoflagellates and Chlorophytes were the minor groups,but the former became important sporadically in the autumn.It was suggested that there was distinctive variation in both the phytoplankton community structure and biomass between summer and autumn in the Xiamen Western Bay and the latter was coupled to the changes in temperature and dissolved oxygen.However,the spatial variation of the phytoplankton community structure was not as clear as the trend in the biomass of phytoplankton among all the sites in this bay.  相似文献   

Mass transfer in double white dwarf binaries     

Juhan Frank   《New Astronomy Reviews》2008,51(10-12):878

I review the implications of our recent numerical simulations of the hydrodynamics of Roche lobe overflow in double white dwarf binaries, with special emphasis on the stability and survival of such systems after the onset of dynamically unstable mass transfer. We find that some of these systems may survive and enter a secular phase of orbital expansion, driven by gravitational radiation, undergoing slow and decreasing mass transfer, and be observable as AM Canum Venaticorum binaries.  相似文献   

Degradation of Recalcitrant Textile Dyes by Coupling Fungal and Photocatalytic Membrane Reactors          下载免费PDF全文

Ece Ümmü Deveci  Nadir Dizge  Hüseyin Cengiz Yatmaz  Berrin Tansel 《洁净——土壤、空气、水》2016,44(10):1345-1351

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近2600年来内蒙古居延海湖泊沉积物的色素含量及环境意义   总被引：10，自引：0，他引：10  

瞿文川  吴瑞金  王苏民  张振克 《沉积学报》2000,18(1):13-17

通过分析东居延海S₁探坑剖面色素含量,结合碳酸盐、介形类化石、腐殖酸、磁化率及化学元素等多环境指标分析结果,探讨该区近 2 6 0 0年来环境气候波动特点。研究区气候变化大致经历几个阶段:温暖湿润(2 6 5 0～ 2 5 6 0aB.P.)→湖泊菱缩,气候偏干暖 (2 5 6 0～ 2 36 0aB.P.)→暖湿气候背景下湖泊的扩张 (2 36 0～2 1 2 0aB.P.)→冷湿向冷干转换,湖泊由大湖开始菱缩 (2 1 2 0～ 1 6 0 0aB.P.)→气候暖湿,湖泊再次扩张,(1 6 0 0～ 6 5 0aB.P.)→湖泊由扩张到菱缩,气候由冷湿向暖干变化 (6 5 0aB.P.-至今 )。同时尝试把色素与其它指标的结合作为指示湖泊古初始生产力的有效性,以及识别沉积记录有关人类活动的可能性。  相似文献   

Fossil pigments as indicators for palaeoclimatic interpretations —A case study of Qinghai Lake     

Han Xiaozhong  Shen Han  Wang Sumin  Yu Yuansheng 《中国海洋湖沼学报》1992,10(4):320-324

An 82 cm core was collected from Qinghai Lake in the Qinghai-Xizang Plateau, China and sectioned in intervals of 1 cm for analysis of pigments (i. e. chlorophyll derivatives, carotenoids, myxoxanthophyll, oscillaxanthin) and²¹⁰Pb.²¹⁰Pb dating was used to establish the chronological sequence. The concentrations of myxoxanthophyll and oscillaxanthin from the cyanophytes increase with temperature. There are four peak values at 0–14 cm (present−1891a), 25 cm (1786a), 45 cm (1581a), 60 cm (1416a) representing four warm and low water level periods during the past 700 years. This was confirmed by the high concentration of carbonate and ∂¹³C in these stages. In these 700 years, there were also 4 periods of cold wet climate and high water level as indicated by the tree ring index and high value of native chlorophyll and high, variable CD/TC ratios. The project was supported by the Loess and Quaternary Research Lab, Academia Sinica.  相似文献   

三种紫菜叶状体对高温胁迫的生理响应   总被引：4，自引：0，他引：4       下载免费PDF全文

陈伟洲  许俊宾  吴文婷  姜红霞  朱建一  陆勤勤 《热带海洋学报》2015,34(1):49-55

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空间视角下旅游休闲场所的主客关系 ——以广州白天鹅宾馆大堂为例     

古恒宇  陶伟 《热带地理》2021,41(1):82-92

利用空间句法理论对广州市白天鹅宾馆大堂的空间组构规律进行分析,并结合深度访谈、参与式观察等质性分析方法,探究空间因素在主客交往过程中的作用机制。结果发现：1）酒店大堂呈现“视觉整合统一,空间分割互补”的空间构型特征,该特征与游客需求相适应。2）大堂中的主客关系表征出接触时间短、受限于特定时空间、地位不平衡等特点,游客在主客关系中的地位高于酒店员工,酒店的盈利性是塑造主客关系不平衡性的主要原因。3）空间对不平衡主客关系的塑造和维持具有重要意义：大堂空间“迎合”了各类旅游休闲者的需求,促进其旅游休闲体验的提升,同时“规训”了酒店员工的行为;空间对部分酒店员工产生了正向的“外溢”作用;空间是展现酒店服务水平的“门面”和“舞台”,酒店管理者试图通过大堂的空间设计维持不平衡的主客关系。4）酒店管理者及员工有意图地为游客营造“家”的感受,提升其满意度及出行体验。“家”的建构与游客现代性背景下的情感有关,在特定的空间构型下可外化为舒适性、便利性等诸多体验,并作用于其消费等行为。  相似文献