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设计合成一种尚未见文献报道的酚醚型双臂开链冠醚化合物L(L=2,6-二(8’-喹啉氧甲基)-4-甲基-苯甲醚)，经元素分析、IR、1HNMR、MS等方法确定了其组成和结构。其Ag(Ⅰ)、Cu(Ⅱ)、Ni(Ⅱ)固体配合物的元素分析结果表明金属离子不同，则其配合物的配位比(M∶L)不同，Ag(Ⅰ)配合物为1∶1，Cu(Ⅱ)、Ni(Ⅱ)配合物为2∶3。并运用热重-差热分析对其热稳定性进行初步研究。 相似文献
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虫动物系动物界的一个小门，属真体腔原口动物。海生，世界种约１４０种，我国黄渤海目前发现４种，分隶于２目，２科，４属，其中有一新种－青岛池体Ｉｋｅｄｏｓｍａ？ｑｉｎｇｄａｏｅｎｓｅｓｐ．ｎｏｖ。现将该４种的分类、分布和生态特点记述如下： 相似文献
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Sofia Loureiro Esther Garcs Margarita Fernndez-Tejedor Dolors Vaqu Jordi Camp 《Estuarine, Coastal and Shelf Science》2009,83(4):539-549
Samples were collected during one annual cycle (April 2007–March 2008) at Alfacs Bay (NW Mediterranean Sea) central station in order to assess the influence of organic nutrients in the growth of the microalgae assemblage, with special reference to Pseudo-nitzschia spp. This potentially toxic diatom forms natural and recurrent blooms in the study area. To assess further the relationship between Pseudo-nitzschia spp. and nutrients an enrichment experiment with high molecular weight dissolved organic matter (HMWDOM) was performed with field samples obtained during a Pseudo-nitzschia spp. bloom. HMWDOM was extracted from water collected at Alfacs Bay. Five bioassays were prepared: N + P (seawater with addition of nitrate and phosphate), DOM (addition of HMWDOM), (−N + P) + DOM (nitrogen deficient, with addition of phosphate and HMWDOM), (N + P) + DOM (addition of nitrate, phosphate and HMWDOM), seawater control (without added nutrients), and B + DOM (control of bacteria, without microalgae). The experiment was run in batch mode over 4 days. Results from the field study revealed that the concentrations of organic nutrients mostly surpassed the inorganic pool. Pseudo-nitzschia spp. was the most frequent and abundant taxa of the microalgae community. The micro-planktonic assemblage was arranged according to a seasonal factor (ANOSIM and cluster analysis). DON, nitrate and silicate were the most important abiotic parameters contributing to the dissimilarities between seasons (SIMPER analysis) and thereby potentially influencing the seasonal distribution of microalgae in the representative station. In the experimental investigation, Pseudo-nitzschia cells increased by the end of the experiment in the DOM bioassay but no respective increase was observed for chlorophyll a. This could point to an acquisition of nutrients through the DOM fraction that would conjointly reduce the need of chlorophyll a. The data obtained suggest that organic nutrients may exert an important role in the development of microalgae, including Pseudo-nitzschia spp., in the selected location. 相似文献
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摄食对凡纳滨对虾耗氧率和氮、磷排泄率的影响 总被引：9，自引：0，他引：9
在实验室条件下测定了凡纳滨对虾Litopenaeus vannam ei在不同温度和体质量条件为空腹状态和饱食状态下的耗氧率和氮、磷排泄率,探讨了不同条件下因摄食引起的特殊动力作用(SDA)和外源性氮、磷排泄率。结果表明,温度和体质量对凡纳滨对虾的基础代谢和摄食代谢都有显著的影响。凡纳滨对虾摄食后的耗氧率平均提高44.5%,SDA平均为0.120 mg.(g.h)-1,摄食后氮排泄率平均提高42.9%,磷排泄率平均提高37.0%;氮、磷排泄率的比值(N/P)也显著提高,其内源氮排泄率/内源磷排泄率为11.11,外源氮排泄率/外源磷排泄率为27.71。 相似文献
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The authors have isolated and characterized a novel serine palmitoyltransferase(SPT)-like gene in marine Emiliania huxleyi virus(EhV-99B1).The open-reading frame(ORF) of EhV99B1-SPT encoded a protein of 496 amino acids with a calculated molecular mass of 96 kDa and Ip 6.01.The results of sequence analysis showed that there was about 31%-45% identity in amino acid sequence with other organisms.The maximum likelihood phylogenetic tree suggested that the EhV99B1-SPT gene possibly horizontally transferred from the eukaryote.Hydrophobic profiles of deduced amino acid sequences suggested a hydrophobic,globular and membrane-associated protein with five transmembrane domains(TMDs) motifs.Several potential N-linked glycosylation sites were presented in SPT.These results suggested that EhV99B1-SPT was an integral endoplasmic reticulum membrane protein.Despite lower sequence identity,the secondary and three-dimensional structures predicted showed that the "pocket" structure element composed of 2α-helices and 4βsheets was the catalytic center of this enzyme,with a typical conserved "TFTKSFG" active site in the N-terminal region and was very close to those of prokaryotic organisms.However,the N-terminal domain of EhV99B1-SPT most closely resembled the LCB2 catalysis subunit and the C-terminal domain most closely resembled the LCB1 regulatory subunit of other organisms which together formed a spherical molecule.This "chimera" was highly similar to the prokaryotic homologous SPT.For a functional identification,the EhV99B1-LCB2 subunit gene was expressed in Escherichia coli,which resulted in significant accumulation of new sphingolipid in E.coli cells. 相似文献
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Abstract. .The phosphate uptake kinetics of single cells and colonies of the haptophycean alga Phaeocystis pouchetii were investigated in short- and long-term experiments. In phosphate-deprived cultures, the highest nutrient uptake rate (Vmax ) of both growth forms appeared to be similar. However, the half-saturation constant for phosphate uptake of the cells embedded in a colony (Ks = 3.08 μM) was considerably higher than that of the single cells (Ks = 0.31 μM). This is consistent with the existence of a diffusion barrier formed by the colony membrane and colonial mucus. Over a 24 h light/dark cycle, the phosphate assimilation rate in moderately limited colonies and single cells was nearly identical during the light period. In the following dark phase, colony cells maintained this uptake rate, whereas the uptake of the single cells diminished by 70 %. The high dark uptake rate in colonies ran parallel with the absorption and degradation of intracolonial carbon compounds, suggesting that the dissimilation of these compounds covers the energy requirements for phosphate uptake in the dark. In Phaeocystis cultures during a transition to phosphate depletion, a significant amount of phosphate was found in the colonial mucus, isolated by selective filtration. The possible absorption of phosphate by the mucus and the role of mucus in the energy budget seem to be an essential feature of phosphate uptake of colonies. Short-term measurement of phosphate uptake in colony cells may therefore underestimate the phosphate uptake of the whole colony. 相似文献
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性外激素诱导大弹涂鱼成熟和产卵 总被引：6，自引：0，他引：6
成熟大弹涂鱼的卵巢、精巢和储精囊稀释液中的性外激素以及缩宫素和脱氧皮质酮（DOC）能诱导第4时相的大弹涂鱼卵母细胞在离体培养的条件下发育成熟，成熟率与性外激素的种类和剂量有关。前列腺素E1（PGE1）单独使用的效果不明显，但与人绒毛膜促性腺激素（HCG）混合使用时显著提高了卵母细胞的成熟率。以卵巢、精巢和储精囊稀释液以及PGE1分别注射雌性大弹涂鱼，剂量为0．01cm^3/尾的卵巢液、0．1cm^3/尾的储精囊液、0．1cm^3／尾的精巢液以及剂量为10μg/尾的PGE1都有诱导卵母细胞成熟的作用，其中储精囊液的作用最为显著。在人工管道中放置大弹涂鱼成熟亲鱼卵巢、精巢或储精囊的稀释液，有诱异性亲鱼进入管道内的作用，其中以储精囊液对雌鱼的吸引作用尤为明显。放置于陶瓷管道或海绵管道内的卵巢、精巢或储精囊稀释液都能诱导大弹涂鱼产卵，在陶瓷管道的产卵量和受精率显著高于海绵管道。 相似文献
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海洋工程人因可靠性研究进展 总被引：9，自引：0，他引：9
海洋结构物在其生命周期的设计、建筑和工作等阶段中发生的灾害性事故（船舶和海洋平台的碰撞、搁浅、腐蚀病劳破坏、沉船、火灾、爆炸等）大多与人为错误和组织错误（ＨＯＥ有关,据统计,大约６０％～９０％的事故意 由ＨＯＥ引起,因此海洋工程中进行人因可靠性分析研究很有必要,在全面回顾近年来各国在这一领域的研究现状,分析和总结人因可靠性评估（ＨＲＡ）研究方法的基础上,重点介绍了失效模式及影响分析（ＦＭＥＡ）,事 相似文献
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本文审查了中国南海感棒水母科、触丝水母科、玛拉水母科和帽冠水母科有关种类。记述了二个新种：隆脊真唇水母，新种Eucheilota carinata sp.nov.和南海盐生水母，新种Halopsis nanhaiensis sp.nov.和二个新记录属种：十字胃水母Staurostoma sp.及阿弗罗八拟杯水母Octophialucium aphrodite（Bigelow，1928）。编制了触丝水母科和玛拉水母科所有已知属和分种的检索表。此外，还简介了中国南海感棒水母科、触丝水母科、玛拉水母科和帽冠水母科已知种类名录及分布。模式标本保存于国家海洋局第三海洋研究所。 相似文献
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中国沿海革囊星虫属(星虫动物门)的研究 总被引：4，自引：0，他引：4
李凤鲁 《中国海洋大学学报(自然科学版)》1989,(3)
本文报导我国沿海革囊星虫属共计14种,内有3种P.onomichianum;P.formosense和P.iaponicum分布在台湾省。陈义(1963年)曾记述过海南岛的9种,其中有3种是同物异名。分布在我国的西沙群岛、海南岛和大陆各省沿海的共11种。现将这些种的区系分布、分类和生态特点记述如下: 相似文献
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《中国海洋大学学报(自然科学版)》2000,30(Z1):247-251
1999年5～6月对大西洋浪蛤进行人工繁殖试 验。结果表明,大西洋浪蛤一年能达到性成熟,一个繁殖季节产卵一次,卵为球形,卵径为 50～60μm;在23℃左右水温下,受精卵经16～20h发育成D形幼虫,幼虫浮游期为16～20d; 壳长260～290μm时为附着变态阶段。幼虫培育盐度要求在16以上。 相似文献
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1 IntroductionMudskipper ( Boleophthalmus pectinirostris ) inhabits muddy burrow in the intertidal mudflats of the temperature zone, feeding mainly on benthic diatoms and adapting to a wide range of salinity[1~3]. Although it is small in size, the mudskipper is delicious, nutritious and has a high market value. Fish farmers in Southeastern Mainland China are eager to culture this species. However, at present the natural resource of the fish has been decreasing or disappearing in some area… 相似文献
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中国的海气相互作用研究(1998-2002) 总被引：2，自引：0，他引：2
概述了近4a年来(1998年7月-2002年7月)中国在大尺度海气相互作用研究方面的进展。包括7个方面的内容：现场观测和海洋考察；热带太平洋海气相互作用研究；与季风有关的海气相互作用研究；北太平洋海气相互作用研究；印度洋海气相互作用研究和全球大洋海气相互作用研究。对上述第二和第三个内容给予了更多的关注，这是因为在准备和组织这篇短文时，大量参考文献集中在热带太平洋区域，诸如：ENSO过程及其动力学和对气候影响。参考文献也涉及到不同时间尺度和空间尺度的现象，例如：季节内变化，季节变化，年际变化，十年际变化等。它们反映了近4a来，从后TOGA时代至CLIVAR的当代重大研究课题。 相似文献
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临清坳陷（东部）的基本构造特征 总被引：2，自引：0，他引：2
临清坳陷（东部）是一勘探程度较低的含油气压，区内断裂发育，构造复杂，本文应用“掀斜变动”原理对我内的构造进行分析，并总结了下第三系盖层层序的基本构造特征。 相似文献
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Gui-Peng Yang Maurice Levasseur Sonia Michaud Michael Scarratt 《Marine Chemistry》2005,96(3-4):315-329
Sixteen surface microlayer samples and corresponding subsurface water samples were collected in the western North Atlantic during April–May 2003 to study the distribution and cycling of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) and the factors influencing them. In the surface microlayer, high concentrations of DMS appeared mostly in the samples containing high levels of chlorophyll a, and a significant correlation was found between DMS and chlorophyll a concentrations. In addition, microlayer DMS concentrations were correlated with microlayer DMSPd (dissolved) concentrations. DMSPd was found to be enriched in the microlayer with an average enrichment factor (EF) of 5.19. However, no microlayer enrichment of DMS was found for most samples collected. Interestingly, the DMS production rates in the microlayer were much higher than those in the subsurface water. Enhanced DMS production in the microlayer was likely due to the higher concentrations of DMSPd in the microlayer. A consistent pattern was observed in this study in which the concentrations of DMS, DMSPd, DMSPp (particulate) and chlorophyll a in the microlayer were closely related to their corresponding subsurface water concentrations, suggesting that these constituents in the microlayer were directly dependent on the transport from the bulk liquid below. Enhanced DMS production in the microlayer further reinforces the conclusion that the surface microlayer has greater biological activity relative to the underlying water. 相似文献
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