38 resultados para G8630 1887 .B6
Resumo:
Three novel series of monomers, namely n-1-bromo-[4-(4-methoxyphenylazo)phenyloxy]-alkanes (Bn, n = 3, 6, 10), n-[4-(4-methoxyphenylazo) phenyloxy]alkyloxy-4-methoxybenzene (Cn, n = 3, 6, 10) and n-[4-(4-methoxyphenylazo)phenyloxyl]alkyloxy-[4-methoxy-2,5-bis-(chloromethyl)] benzene (Dn, n = 3, 6, 10) were synthesized and characterized with FTIR, H-1 NMR, UV-visible and fluorescence spectroscopy. Their thermal behaviour was studied by different scanning calorimetry and polarizing optical microscopy. The results show that B3, B6 and C6 exhibit monotropic nematic liquid crystalline behaviour.
Resumo:
用X射线座滴照像法测量了铝液-氟化物熔盐间的界面张力。采用曲线拟合液滴轮廓坐标的计算机程序处理座滴图像。用逐步回归分析方法获得了计算熔盐密度值的回归方程。讨论了熔盐中NaF/AlF_3分子比,Li_2CO_3和稀土氧化物含量对熔盐-铝液间界面张力的影响。测量了铝液在熔盐中对石墨、工业碳块以及TiB_2涂层的润湿角。
Resumo:
锗是周期表第Ⅳ主族的半金属元素,在地壳中的分布属于典型的稀散元素,土壤中平均约含0.2ppm,很多植物中都含有微量锗,其中许多名贵中药材和茶叶含比较丰富的锗化合物尽管迄今还不能确定锗是人体必须微量元素,但因许多中药的医疗保健作用被认为与其含有相对丰富的有机锗有关,因此,近二十年来锗化合物的生物活性日益受到人们的重视。锗和同族的其它元素类似,也容易生成有机化合物。1887年合成的四乙基锗是世界上合成的第一个
Resumo:
褐虾总科包括褐虾科和镰虾科,是重要的底栖生物类群,而且很多褐虾种为常见的经济种,其中中国北方海域最常见的为日本褐虾Crangon hakodatei Rathbun, 1902,另外黄海褐虾Crangon uritai Kim & Hayashi, 1999在黄渤海也较为常见。在东海和南海,污泥疣褐虾Pontocaris pennata (Bate, 1888)和拉氏爱琴虾Aegaeon lacazei (Gourret, 1887)在底栖生物拖网时常可采到,有很大的经济价值。我国对褐虾总科的研究很少,亟需对我国海域的褐虾进行全面的系统分类学和地理分布研究。 本论文所依据的标本主要为中国科学院海洋研究所海洋生物标本馆馆藏的约1600号褐虾类标本,标本主要采自渤海、黄海、东海、南海四大海域,也有部分标本采自日本海、南极和北极等海域,并得到国外同行专家惠赠的褐虾类标本约100号,同时也检查了其它单位保藏的少量标本。 本论文主要采用传统的形态学方法进行分类学研究,共鉴定出褐虾科14属25种,其中1个新种,6个新记录种,镰虾科1属7种,其中2个新种,3个新记录种。参照历史文献与现在研究结果,中国海域的褐虾类至少有2科11属44种。 本文通过对约1700号标本的详细检查,总结了各个属和种的分类学特征和地理分布特点,对各属的分种均附有详细系统的检索表,对鉴定的32种褐虾均附有详细的背面整体图和侧面整体图以及附肢等的局部形态图,并对各种进行了中文名称的考订。 本研究是我国首次关于褐虾总科的系统分类学和动物地理学研究,研究结果将改变我国在褐虾总科研究报道方面的薄弱现状,并为此动物类群的多样性等研究提供重要的基础资料。研究结果澄清了分类学上存在争议的疑难种,发现了3个新种,报道了9个新记录种,阐明了我国褐虾总科的区系特点。
Resumo:
Descriptions of a new species and two new records of species of the genus Allokepon Markham, 1982 from Chinese waters are presented. The host species were portunid crabs. Allokepon hendersoni (Giard & Bonnier 1887) was found infesting Charybdis bimaculata (Miers), A. monodi (Bourdon, 1967) infesting Portunus pelagicus (L), Portunus trituberculatus ( Miers), and Thalamita sp. and A. longicauda n. sp. infesting Portunus pulchricristatus (Gorden). Three of the host species were recorded for the first time harboring isopod parasites, and the male of A. monodi is presented. Allokepon longicauda n. sp. is distinguished from the other four species found in China by the long slender uropods of females.
Resumo:
A base population of the bay scallop, Argopecten irradians irradians Lamarck, was produced by crossing two cultured bay scallop populations. After 1 year of rearing, the top 10% truncation selection of the top 10% (i=1.755) was carried out in the base population of about 1300 adults. A control parental group with a an identical number to the select parental group was randomly selected from the entire population before isolation of the select parental group. The result showed that, at the larval stage, the growth rate of larvae in the selected line was significantly higher than that of the control (P < 0.05), and that the genetic gain was 6.78%. Owing to the lower density of control at the spat stage, the mean shell length of the control line was larger than that of the select line at day 100. When the same density was adjusted between two lines in the grow-out stage (from day 100 to 160), the daily growth rate of the selected line was significantly higher than that of the control line (P < 0.05). Survival of the select line was significantly larger than that of the control line in the grow-out stage. In conclusion, the results obtained from this experiment indicate that selective breeding from a base population with a high genetic diversity established by mass spawning between different populations appears to be a promising method of genetic improvement in bay scallop, A. irradians irradians Lamarck.
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本文给出一开启式海洋机器人流体动力学模型、去耦方案选择、系统结构设计和仿真,供同行交流。
Resumo:
流域化学侵蚀及其速率与流域生态和环境之间的关系是当前地表地球化学研究的重要前沿领域,其中碳酸盐岩的硫酸风化机制及其与区域碳循环的关系则是科学家们最为关注的科学问题。因此,近年通过研究西南喀斯特流域地表水地球化学对这一科学问题进行了研究,发现西南喀斯特地区河水一般含有较多的SO4^2-,从化学计量学、SO4^2-的占δ^34S和溶解无机碳(DIC)的δ^13C分析发现,硫循环中形成的硫酸广泛参与了流域碳酸盐矿物的溶解和流域侵蚀:西南喀斯特流域碳酸盐岩的侵蚀速率为97t/(km^2·a),消耗COz量为25t/(km^2·a)。对乌江流域河水硫酸盐离子的硫同位素研究结果认为:参与流域侵蚀的硫酸主要来自煤系地层硫化物和矿床硫化物的氧化及大气酸沉降,分别对河水SO4^2-的贡献为50%、27%和20.5%(其余2.5%的SO4^2-为硫酸盐蒸发岩的溶解);硫酸风化碳酸盐岩向大气净释放CO2的总通量为8.2t/(km^2·a),依此计算西南喀斯特区域向大气释放CO2的通量为4.4×10^12g/a,相当于每年西南碳酸盐岩风化消耗CO2总通量的33%。将乌江流域的研究结果对我国大陆碳酸盐岩分布区域进行相应计算发现,硫酸风化碳酸盐矿物向大气释放的C02总通量为28×10^12g/a,相当于全球硅酸盐风化消耗CO2量的26%。硫酸参与流域侵蚀改变了区域碳循环,人为过程可以通过释放酸沉降、矿业活动和土地利用等形式加速流域侵蚀和影响流域元素的生物地球化学循环.