53 resultados para G3764.W8A5 1929 .C5
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中华哲水蚤是黄、东海浮游动物关键种,连接初级生产与较高营养级,在海洋生态系统中占据核心地位。在以往研究基础上,依据2006年3月至2007年8月黄海9个航次、胶州湾11个航次现场调查数据以及大量室内实验数据,本文研究了中华哲水蚤的繁殖、种群补充以及油脂积累的季节变化,期望初步阐明中华哲水蚤在黄海的种群动态及驱动因素、并构建其生活史概念模型。 3、4月份,黄海与胶州湾中华哲水蚤的生殖腺普遍发育成熟、产卵率较高,中华哲水蚤种群进入繁殖、种群补充的活跃期,恰好可以利用此时较好的食物条件。5、6月份,中华哲水蚤在黄海近岸海区仍表现出较高的产卵率,而陆架海区的中华哲水蚤生殖腺成熟度、产卵率逐渐降低,种群逐渐表现出度夏特征C5占优势、积累大量脂类。整个夏季,中华哲水蚤的繁殖率、种群补充率在整个黄海都较低,尤其在黄海冷水团区:中华哲水蚤生殖腺停滞于未成熟的GS1-GS2期,产卵率为零。10月,中华哲水蚤在冷水团边缘潮汐锋区的繁殖、种群补充活跃,或许可以解释秋、冬季近岸种群的恢复。11月之后,随着垂直混合的加强,黄海冷水团逐渐消失,此时陆架区的中华哲水蚤种群结束度夏过程,并以较低的繁殖率进行种群补充,直到次年3、4月份食物环境转好,中华哲水蚤种群出现新一轮繁殖、补充高峰。本文依据中华哲水蚤雌体密度、产卵率、孵化率等计算了中华哲水蚤的种群潜在补充率,我们发现,陆架区种群仅在3、4月份出现较强补充以及冬季的微弱补充,而近岸海区除夏季外,于各个季节均可进行比较活跃的种群补充,其中春季种群补充规模、强度最大;整体来看,春季是黄海中华哲水蚤种群补充的最重要时期。 本文详细研究了中华哲水蚤的繁殖与各种环境、雌体自身因素之间的关系:1、统计结果表明,中华哲水蚤的产卵率与海区食物条件(浮游植物生物量、纤毛虫丰度)之间具有紧密联系,而与油囊体积无关;在饥饿培养条件下,中华哲水蚤只能维持3-6天的产卵,而添加食物2-7天内,即可逐渐恢复产卵;体内积累油脂在饥饿过程中有所消耗,不过仍然不能阻止产卵率的下降;这些结果表明中华哲水蚤繁殖的能量所需主要来自于近期摄食,而体内储存脂类可能主要用于代谢所需,是应对不利条件的一种能量缓冲。2、统计分析表明:产卵率与雌体前体长间具有一定的正相关性,这可能由于体长较长的雌体往往具有较高的怀卵量;产卵率与温度之间没有显著的统计关系,温度可能通过调节中华哲水蚤的代谢率、体长等间接影响到产卵率。3、值得一提的是,本文发现中华哲水蚤的产卵率与其生殖腺成熟度之间具有非常紧密的统计关系,这为通过保存样品估算产卵率以及长期历史样品、数据间的比较提供了可能。 春季硅藻水华是黄海及其邻近海域的重要季节性特征。本文针对硅藻水华与中华哲水蚤繁殖的关系进行了多次现场研究,我们发现,硅藻水华因其发生海区、硅藻优势种类不同而对中华哲水蚤繁殖具有复杂多样的影响。2006年3月,胶州湾东部海区发生中肋骨条藻(Skeletonema costatum)水华,中华哲水蚤的产卵率显著增高,但其孵化率相对较低(50%左右);2007年2月,胶州湾东部发生环纹劳德藻(Landeria annulata)水华,中华哲水蚤卵的孵化率在各种处理下均接近100%;2006年4月,黄海东北部发生太平洋海链藻(Thalassiosira pacifica)水华,产卵率与孵化率均处于调查海区的中等水平;2007年4月,黄海中部海区发生中肋骨条藻水华,中华哲水蚤在此次调查海区平均产卵率高达27.8 卵/雌体/天,远远高于以往同时期的调查结果,孵化率、幼体存活率也普遍较高;此次硅藻水华对于黄海陆架区中华哲水蚤的种群补充具有积极的促进作用。综上,硅藻水华对中华哲水蚤繁殖的影响表现出种类、海区特异性,其具体机理仍需进一步研究。 本文研究了黄海中华哲水C5期油脂积累的区域、季节变化,并探讨了油脂积累对中华哲水蚤的生理、生活史的可能作用。黄海近岸区C5期油囊体积常年较小,而陆架区则表现出明显的季节差异。在陆架区C5期是中华哲水蚤度夏种群的主要组成部分,其油囊体积与度夏过程有密切联系:最大油囊体积(可占前体部体积的30%以上)出现于度夏准备期(5、6月),随着度夏过程的进行,油囊体积因代谢而不断消耗,至12月时,油囊体积降低到与近岸种群无异。次年4月以后,油脂积累可能随食物条件转好而再次开始积累。我们认为黄海中华哲水蚤所积累油脂除了可以为休眠提供能量以克服较长时期食物缺乏之外,还可能是休眠的诱导因素,对其生活史具有重要意义。 黄海近岸海区与陆架海区在水团特征、中华哲水蚤种群丰度与结构、繁殖特征、种群补充、油脂储存策略等方面具有显著差异,因此,本文分别讨论了这两个区域中华哲水蚤的生活史。黄海陆架海区中华哲水蚤在全年共有4-5个世代:11月末,中华哲水蚤结束度夏过程,种群中占优势C5期个体开始蜕皮为成体、逐渐成熟、繁殖,由此产下的子代可称之为G0,此世代在食物条件较差的冬季发育成熟后可以产下G1;G1于3月初发育成熟,恰逢春季较好的食物条件,于是在3月初-5月中旬很可能发育G2、G3两个世代;假若陆架区食物环境适宜,5月中旬后很可能产生新的世代—G4;G3与G4两个世代的混合种群共同进入度夏过程,期间,一小部C5蜕皮为成体,大部C5保持滞育状态;至12月冷水团消退后,G3、G4世C5蜕皮、成熟,开始新的生活周期。中华哲水蚤生殖腺成熟度、油囊体积的季节变化与上述概念模型具有较好的对应关系,另外,这两个参数简单易用、对环境变化敏感,可以尝试应用于气候变化与桡足类关系等长期研究中。 以往的研究更多的关注于黄海陆架区的中华哲水蚤种群,对近岸种群的关注较少,本文初步探讨了近岸种群的种群补充、世代情况。相对于陆架区,黄海近岸区中华哲水蚤的生活史更为复杂,区域差异较大。近岸海区中华哲水蚤产卵率、种群周转率较高;同时,近岸海区是多种鱼类的产卵场、索饵场,该区域的各营养级间的能量流动对黄海海洋生态系统的结构功能至关重要。因此,在将来的研究中,近岸海区中华哲水蚤种群的生态学、生活史应该受到同样的重视。
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The vertical distribution and stage-specific abundance of Calanus sinicus were investigated on three key transects in the southern Yellow Sea and the northern East China Sea in August 1999. The results showed that in summer C. sinicus shrank its distribution area to the central cold (less than or equal to10degreesC) bottom water in the Yellow Sea, i.e. the Yellow Sea Cold Bottom Water, remaining in high abundance (345.7 ind m(-3)). In the northern East China Sea on a transect from the mouth of the Yangtze River to the Okinawa trench, only a few individuals appeared in the inner side and none had been found either in the upper layer or in the deep layer of the outer shelf area. The population of C. sinicus in YSCBW consisted of mainly adults (46.83%) and C5 (37.41%). C1-C4 only accounted for 15.76%. The low proportion of the earlier copepodite stages and the high female:male ratio (11.39) indicated that the reproduction of C. sinicus in YSCBW was at a very low level due to the low temperature and low food concentration. It is concluded that the dramatic decrease of C. sinicus population in the shelf area of China seas in summer is caused by the shrinkage of its distribution area and the YSCBW served as an oversummering site.
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The jinjiang oyster Crassostrea rivularis [Gould, 1861. Descriptions of Shells collected in the North Pacific Exploring Expedition under Captains Ringgold and Rodgers. Proc. Boston Soc. Nat. Hist. 8 (April) 33-40] is one of the most important and best-known oysters in China. Based on the color of its flesh, two forms of C rivularis are recognized and referred to as the "white meat" and 11 red meat" oysters. The classification of white and red forms of this species has been a subject of confusion and debate in China. To clarify the taxonomic status of the two forms of C. rivularis, we collected and analyzed oysters from five locations along China's coast using both morphological characters and DNA sequences from mitochondrial 16S rRNA and cytochrome oxidase 1, and the nuclear 28S rRNA genes. Oysters were classified as white or red forms according to their morphological characteristics and then subjected to DNA sequencing. Both morphological and DNA sequence data suggest that the red and white oysters are two separate species. Phylogenetic analysis of DNA sequences obtained in this study and existing sequences of reference species show that the red oyster is the same species as C. ariakensis Wakiya [1929. Japanese food oysters. Jpn. J. Zool. 2, 359-367.], albeit the red oysters from north and south China are genetically distinctive. The white oyster is the same species as a newly described species from Hong Kong, C. hongkongensis Lam and Morton [2003. Mitochondrial DNA and identification of a new species of Crassostrea (Bivalvia: Ostreidae) cultured for centuries in the Pearl River Delta, Hong Kong, China. Aqua. 228, 1-13]. Although the name C. rivularis has seniority over C. ariakensis and C. hongkongensis, the original description of Ostrea rivularis by Gould [1861] does not fit shell characteristics of either the red or the white oysters. We propose that the name of C. rivularis Gould [1861] should be suspended, the red oyster should take the name C. ariakensis, and the white oyster should take the name C. hongkongensis. (C) 2004 Elsevier B.V. All rights reserved.
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Oysters are commonly found on rocky shores along China's northern coast, although there is considerable confusion as to what species they are. To determine the taxonomic status of these oysters, we collected specimens from nine locations north of the Yangtze River and conducted genetic identification using DNA sequences. Fragments from three genes, mitochondrial 165 rRNA, mitochondria! cytochrome oxidase I (COI), and nuclear 285 rRNA, were sequenced in six oysters from each of the nine sites. Phylogenetic analysis of all three gene fragments clearly demonstrated that the small oysters commonly found on intertidal rocks in north China are Crassostrea gigas (Thunberg, 1793), not C. plicatula (the zhe oyster) as widely assumed. Their small size and irregular shell characteristics are reflections of the stressful intertidal environment they live in and not reliable characters for classification. Our study confirms that the oysters from Weifang, referred to as Jinjiang oysters or C. rivularis (Gould, 1861), are C. ariakensis (Wakiya, 1929). We found no evidence for the existence of C. talienwhanensis (Crosse, 1862) and other Crassostrea species in north China. Our study highlights the need for reclassifying oysters of China with molecular data.
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研究细穗香薷(Elsholtzia ianthina)的挥发油成分.采用水蒸气蒸馏法提取,用气相色谱质谱联用技术进行分析,用面积归一法计算出有关的相对含量,鉴定出45个化合物,主要的挥发油化学成分为三环[4.3.1.13,8]十一烷-1-醇,2,3,5,6-四甲基酚,共占挥发油总量的56.29%.
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简要介绍了物流的发展现状 ,详细描述了基于CAN总线的物流拣选系统的结构、供电方式和参数设定方法 ,并为系统硬件设计中的电源转换、总线驱动和地址译码等公共电路以及总线控制器、电子标签和指示灯控制器等主要设备提供了设计方案 ,为系统软件设计中C5 1编译、通信协议、命令类型和程序控制规划等问题给出了相应的解决方法 ,还与进口同类产品的性能和价格进行了比较
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本文运用 H-D 变换的基本原理,结合极坐标变换导出了产生n自由度多关节机器人工作空间的递推算法,当给定了机器人的结构尺寸,即可将机器人工作空间在一特定平面内的边界图形用计算机打出并计算出机器人工作空间容积。在本文的另一部分介绍了两种计算机器人工作空间的性能指标,最后用几个机器人的结构参数进行计算和讨论。
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采用气相色谱- 质谱对采自云南白马雪山土壤中并经分离和发酵培养的被孢霉菌株SM96 的菌丝体油脂中脂肪酸组成进行了定性分析和峰面积相对含量测定, 共检测出30 种脂肪酸, 其中多不饱和脂肪酸含量为62. 4 % , 主要为亚油酸、α-亚麻酸(ALA) , 还有少量的γ- 亚麻酸、二十碳三烯酸、花生四烯酸和二十碳五烯酸( EPA) 等, 结果表明该菌株能产生EPA。