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东山湾海水中Fe(II)和Fe(III)相互转化围隔实验研究 总被引：1，自引：0，他引：1
根据2008 年8 月与11 月在东山湾海域获得的调查资料对表层水中溶解态Fe(II)和Fe(III)含量、浮游植物叶绿素a、营养元素及其浓度等环境参数进行分析。结果表明, 夏、秋季海水中Fe(II)浓度及其在总溶解铁中所占比例均与浮游植物叶绿素a 呈正相关, 其相关系数分别为0.7959、0.9219。现场围隔实验表明, 海水中总溶解态Fe 含量在24 h 内有较大的变化, 最大减少量达到17.4%。DS2 站点海水中Fe(II)浓度及其在总溶解铁中所占比例随光照强度增加而增加。最高值与初始值相比较, 叶绿素a 较高的DS2 站点海水中Fe(II)浓度增加较叶绿素a 较低的DS5 号站点高0.053μg/L。Fe(II)和Fe(III)加富实验研究了溶解态的Fe(II)和Fe(III)在海水中相互转化。高浓度的Fe(II)在海水中被氧化成Fe(III),海水中浮游植物也会引发光还原作用使Fe(III)还原成Fe(II)。 相似文献
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在1985年进行长江口调查时,采到了数个双壳类标本,经鉴定认为系帮斗蛤科一新种——中华帮斗蛤Pandora(Frenamya)sinica sp. nov.。新种左壳前主齿和中主齿为一横向的隔板相连结。右壳中主齿发达,后主齿短小。模式标本保存于中国科学院海洋研究所内。 相似文献
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标准卵磷脂氢过氧化物(PC-OOH)与亚油酸甲酯氢过氧化物(ML-OOH)制备 总被引：1，自引：0，他引：1
报道了用自由基引发剂（ＡＡＰＨ）引发氧化,反相高效液相色谱法分离卵磷脂（Ｐｈｏｓ－ｐｈａｔｉｄｙｌｃｈｏｌｉｎｅ,ＰＣ）及其氢过氧化物（ＰＣ－ＯＯＨ）,获得纯品ＰＣ－ＯＯＨ,以及５０℃自动氧化后,用硅胶柱层析分离亚油酸甲酯（ＭｅｔｈｙｌＬｉｎｏｌｅａｔｅ,ＭＬ）及其氢过氧化物（ＭＬ－ＯＯＨ）,而获得标准ＭＬ－ＯＯＨ的方法。 相似文献
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The production of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) by marine microalgae was investigated to elucidate more on the role of marine phytoplankton in ocean-atmosphere interactions in the global biogeochemical sulfur cycle.Axenic laboratory cultures of four marine microalgae–Isochrysis galbana 8701,Pavlova viridis,Platymonas sp.and Chlorella were tested for DMSP production and conversion into DMS.Among these four microalgae,Isochrysis galbana 8701 and Pavlova viridis are two species of Haptophyta,while Chlorella and Platymonas sp.belong to Chlorophyta.The results demonstrate that the four algae can produce various amounts of DMS(P),and their DMS(P) production was species specific.With similar cell size,more DMS was released by Haptophyta than that by Chlorophyta.DMS and dissolved DMSP (DMSPd) concentrations in algal cultures varied significantly during their life cycles.The highest release of DMS appeared in the senescent period for all the four algae.Variations in DMSP concentrations were in strong compliance with variations in algal cell densities during the growing period.A highly significant correlation was observed between the DMS and DMSPd concentrations in algal cultures,and there was a time lag for the variation trend of the DMS concentrations as compared with that of the DMSPd.The consistency of variation patterns of DMS and DMSPd implies that the DMSPd produced by phytoplankton cells has a marked effect on the production of DMS.In the present study,the authors’ results specify the significant contribution of the marine phytoplankton to DMS(P) production and the importance of biological control of DMS concentrations in oceanic water. 相似文献
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磺胺甲基唑和恩诺沙星在日本囊对虾体内的药代动力学研究 总被引：1，自引：0，他引：1
为了研究磺胺甲基唑(Sulfamethoxazole, 简称SMZ)和恩诺沙星(Enrofloxacin, 简称ERFX)在日本囊对虾(Marsupenaeus japonicus)体内的药物代谢动力学特点, 在水温21℃±0.5℃, 盐度29.91 的条件下, 应用萃取、液相测定和反相高效液相色谱法(RP-HPLC)对药物平均回收率、主要动力学参数及在3种组织中的半衰期进行了测定, 检测数据经药物代谢动力学软件3p97 进行研究。结果表明, SMZ 和ERFX 在对虾肝脏、肌肉和血淋巴的平均回收率分别为90.09％, 88.92％, 84.84％和89.14％, 86.04％,91.77％。药物代谢动力学分析表明, SMZ 单次腹部肌肉注射日本囊对虾, 其肝脏药时数据符合二室模型, 肌肉和血淋巴药时数据符合一室模型,半衰期为19.1284, 4.5799, 9.1855 h。ERFX 单次腹部肌肉注射日本囊对虾, 其肌肉药时数据符合二室模型, 肝脏和血淋巴药时数据符合一室模型。半衰期分别为15.16, 16.83, 17.19 h。通过两种药物的代谢特征比较分析表明, SMZ 在肌肉中吸收较ERFX 快, ERFX在血淋巴和肝脏中吸收较SMZ 快。根据SMZ 和ERFX 在21℃±0.5℃的条件下的主要动力学参数及3种组织内消除半衰期, 建议SMZ 在日本囊对虾的休药期不少于10 d, ERFX 的休药期不少于12 d。 相似文献
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The distributions of DMS and its precursor dimethylsulfoniopropionate, in both dissolved (DMSPd) and particulate fractions (DMSPp) were determined in the seasurface microlayer and corresponding subsurface water of the Jiaozhou Bay, China and its adjacent area in May and August 2006. The concentrations of all these components showed a clear seasonal variation, with higher concentrations occurring in summer. This can be mainly attributed to the higher phytoplankton biomass observed in summer. Simultaneously, the enrichment extents of DMSPd and DMSPp in the microlayer also exhibited seasonal changes, with higher values in spring and lower ones in summer. Higher water temperature and stronger radiant intensity in summer can enhance their solubility and photochemical reaction in the microlayer water, reducing their enrichment factors (the ratio of concentration in the microlayer to that in the corresponding subsurface water). A statistically significant relationship was found between the microlayer and subsurface water concentrations of DMS, DMSP and chlorophyll a, demonstrating that the biogenic materials in the microlayer come primarily from the underlying water. Moreover, our data show that the concentrations of DMSPp and DMS were significantly correlated with the levels of chlorophyll a, indicating that phytoplankton biomass might play an important role in controlling the distributions of biogenic sulfurs in the study area. The ratios of DMS/chlorophyll a and DMSPp/chlorophyll a varied little from spring to summer, suggesting that there was no obvious change in the proportion of DMSP producers in the phytoplankton community. The mean sea-to-air flux of DMS from the study area was estimated to be 5.70 μmol/(m2·d), which highlights the effects of human impacts on DMS emission. 相似文献
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全面收集1988—2025年中国地球观测卫星(和飞船)计划,包括历史的、运行中的和列入未来计划的。详细介绍风云卫星系列(FY-n)、海洋卫星系列(HY-n)、资源卫星系列(ZY-n)、环境卫星系列(HJ-n)、中国遥感卫星系列(CRS-n)、灾害监测星座/北京小卫星(DMC/BJ-1)、神舟飞船系列(SZ-n)和天宫空间站系列(TG-n)等8个卫星(和飞船、空间站)系列。这些卫星(和飞船、空间站)系列都提供对海洋的观测,从而构成中国卫星海洋观测系统。按装载的传感器分类,进而给出中国的海色、海表温度、海面高度、海面风场和合成孔径雷达(SAR)卫星观测系统。对中国海洋观测卫星与国际海洋观测卫星装载的传感器性能作了比较和讨论,指出差距。列出目前在轨运行的中国海洋卫星观测系统38个传感器及其类似的国外卫星传感器。 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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ZHANG Xiaojun FANG Hai CHEN Cuizhen ZHAN Wenbin JIN Xiaomin WANG Xiuyun 《海洋学报(英文版)》2005,24(3):131-140
Appropriate pathogenic bacteria were isolated from diseased (or dead) flounder (Paralichthys olivaceus L) occurring in a mariculture farms of Qinhuangdao, which all diseased fishes expressed bacterial septicaemia. The phenotypic information of the 12 pure cultures was studied extensively, including morphological characteristics, colony characteristics in different media, physiological and biochemical characteristics, and the mole fraction G C ratio of the DNA for representative strain. The results show that the isolates belong to a new species of Vibrio, and are designated as Vibrio qinhuangdaora sp.nov, by the area from which the diseased flounders are collected (Qinhuangdao) based on its biological properties following Rules of International Code of Nomenclature of Bacteria. At the same time,studies on the serum homology ofisolates, and pathogenicity of isolates were conducted by experimental infection. The results show that all the isolates are of serologic similarity, and the isolates have strong pathogenicity to flounder. The studies can extensively reflect the main biological properties of this new species of Vibrio. 相似文献
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A sample of coastal marine fulvic acids (mfua) was studied and its binding site structures that form stable complexes with metal ions were identified. A previously developed self-modeling methodology, based on the coupling of synchronous fluorescence (SyF) spectroscopy with evolving factor analysis (EFA), was used for the analysis of the interactions between mfua and two metal ions that act as probes for binding sites, namely Be(II) and Al(III). Two types of binding site structures were detected, probably of the salicylic acid and catechol types. The values of the conditional stability constants between mfua and the two metal ions were: for Be(II), at pH = 6, log K = 5.32(8); for Al(III), at pH = 4, log K = 5.1(2). The concentration of the corresponding binding sites was found to be less than one half of those found for soil fulvic acid samples. 相似文献
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固定化鲅鱼乙酰胆碱酯酶的制备及部分性质测定 总被引：3，自引：0，他引：3
酶的固定化是酶传感器制备过程中重要的1个环节.研究采用直接共价法固定鲅鱼乙酰胆碱酯酶（AChE）.制备方法为：0.1g CNBr活化的Sepharose 4B凝胶用1mmol/L的HCl充分溶胀后,与活力为10U的AChE溶液混合,于4℃下150r/min振荡8h.所制备的固定化酶活力回收率较高（96%）,对pH值和温度变化的适应能力均优于非固定化酶;在3个月保存期内,前者的活力损失13%,而后者的活力则下降89%.这说明固定过程能够大大提高AChE的抗逆性和保持酶活力的稳定,有利于酶传感器的制备. 相似文献
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二甲基亚砜(DMSO)是海水中的主要溶解态甲基硫化物,DMSO在二甲基硫(DMS)的生物地球化学循环中起着重要的作用。它能通过DMS的光化学氧化和细菌氧化生成,可作为DMS的1个汇,也可以通过生物直接合成或其它途径产生。DMSO同时又可以被酶、细菌、植物等还原为DMS,因此,DMSO又可充当DMS的1个源。DMSO除了能被还原为DMS外,还可能会被细菌氧化为SO42-,在氯过氧化物酶作用下被H2O2氧化为DMSO2等。海洋中DMSO的测定通常采用还原剂NaBH4将其还原为DMS后,再利用气相色谱进行测定。海水中DMSO的分布不均匀,高浓度区是那些温度较高,光照充足、浮游植物较多、生物活性较高的表层水或近岸水。 相似文献
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甲壳素钠/羧甲基纤维素钠共混复合纳滤膜的制备及性能研究 总被引：2，自引：0，他引：2
以甲壳素钠和羧甲基纤维素钠共混液为铸膜液,在聚丙烯腈超滤底膜上流延成膜,以丙三醇三缩水甘油醚(PTGE)的乙醇溶液为交联剂交联制得一种新型的复合纳滤膜。该膜的最佳制备条件为:甲壳素钠溶液与羧甲基纤维素钠溶液质量混合比为2∶1,交联剂丙三醇三缩水甘油醚浓度为0.6%,在50℃交联20 h。膜负电荷来源于底膜部分水解。膜的静电位为-0.12 mV,电压渗系数为-13.07 mV/MPa;截留分子量为610 g.mol-1,膜孔半径约0.7 nm。该膜对电解质溶液的截留性能主要决定于荷负电膜对不同电解质离子之间的静电作用力大小。 相似文献
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以大连海洋大学农业部北方海水增养殖重点实验室培育的已明确年龄(1龄、2龄、3龄)的仿刺参(Apostichopus japonicus)为实验材料,采用原位压片法对仿刺参棘、体壁、触手、管足、纵肌、呼吸树、肠7种组织标本进行骨片形态学观察和SPSS统计分析,获得了不同年龄、组织仿刺参中各类型骨片的相对比例。结果表明,原位压片法得到的骨片较Na Cl O法结构损坏较小,且能观察到骨片在组织中的分布。仿刺参各组织中存在桌形体、扣形体、杆状体、花纹状体、复合盘状骨片和长孔状体6种主要骨片类型。体壁中主要骨片类型为扣形体和桌形体;棘和触手中主要骨片类型为扣形体、桌形体和杆状体;管足中主要骨片类型为特有的复合盘状骨片、扣形体和桌形体;呼吸树和肠中主要骨片类型为花纹状体;纵肌不含任何类型骨片。不同组织间相同类型骨片的形态结构一致,无组织间特异性。通过对不同年龄仿刺参各组织的骨片比较分析发现,不同年龄仿刺参相同组织中骨片比例存在差异,例如,1龄、2龄、3龄仿刺参触手中桌形体骨片的相对比例分别为11.55%±2.69%、20.76%±2.34%、3.75%±0.72%,2龄仿刺参触手中桌形体骨片的相对比例显著高于1龄、3龄仿刺参触手中桌形体骨片比例(P0.05);1龄、2龄、3龄仿刺参棘中扣形体相对比例分别为92.55%±1.98%、65.45%±1.79%、88.36%±3.08%,2龄仿刺参棘中扣形体相对比例显著低于1龄和3龄仿刺参棘中扣形体骨片比例(P0.05)。本研究为仿刺参的基础生物学研究提供资料,为仿刺参的年龄鉴别提供参考。 相似文献
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1Introduction Afossorialmodeoflifehasbeenadoptedbynu merousfishes(Gibson,1982).Burrowingmodeof lifeclearlyoffersanumberofadvantages,butburro wingfishmustalsobeadaptedtocopewiththespe cialproblemsthatthislifestylepresents.Fishthat constructburrowsininterti… 相似文献