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本研究提出了一种用于检测海水中锌离子（Zn2+）含量的电化学检测方法。该方法首先应用水热法合成SiO2@PDA-Sb复合材料，然后将该复合材料修饰到玻碳电极上制备SiO2@PDA-Sb-Nafion/GCE，利用差分脉冲阳极溶出伏安法（DPASV）对珠江口海水水样中Zn2+进行测定。研究结果表明，Zn2+在SiO2@PDA-Sb-Nafion/GCE上具有较强的溶出峰。在最优条件下，SiO2@PDA-Sb-Nafion/GCE对Zn2+浓度在1~1 000 nmol/L范围内可实现灵敏、准确的检测，Zn2+的检测出限为0.71 nmol/L。加标回收率实验显示Zn2+加标回收率为93.19%~100.12%，表明该方法可应用于现场海水样品Zn2+测定。本方法具有电极制作简单、稳定性和抗干扰性良好，能够提高现有测定方法的检测限和精确度，在现场海水检测痕量Zn2+具有较好的应用前景。 相似文献
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从胶州湾污染区域的沉积物样品中筛选获得1株对重金属元素反应敏感的菌株,经鉴定为灰黄青霉(Penicillium griseofulvum),对该菌株在重金属胁迫下的生物学特征及酶的活性变化进行了研究,结果表明,一定量的重金属铜、锌离子对菌株产生显著的影响,并通过形态与色素变化的方式表现出来。当培养基中 Cu2+浓度为125 mg/dm3,Zn2+浓度为800 mg/dm3时,孢子萌发会完全受到抑制,同时菌丝也发生严重变异。菌株色素随着 Cu2+浓度的增加呈现从灰绿色到浅黄色的颜色变化,随着Zn2+浓度的增加呈现从灰绿色到白色的颜色变化。在菌株生长的离子浓度范围内,一定量的 Cu2+浓度能提高 CAT,GOD 酶的活性作用,在Cu2+浓度为25 mg/dm3时活性作用最强;在25~75 mg/dm3时,随着 Cu2+浓度的增加,活性作用逐渐减弱,浓度增加至100 mg/dm3时菌丝不能生长。Cu2+对菌体金属硫蛋白的影响不规则。在 Zn2+浓度为100~400 mg/dm3的培养基中,CAT,GOD酶和金属硫蛋白的活性作用随着Zn2+浓度的增加逐渐增强,在Zn2+浓度为400 mg/dm3时酶和金属硫蛋白活性达到最强。Zn2+浓度增加至600 mg/dm3 时,菌株不能生长。 相似文献
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可口革囊星虫(Phascolosoma esculenta)重组铁蛋白富集Pb2+等重金属特性和功能研究 总被引：1，自引：1，他引：0
利用可口革囊星虫重组铁蛋白富集Pb2+、Fe3+、Cd2+、Cr3+、Cu2+、Mn2+、Sn2+和Zn2+等8 种重金属离子后, 通过透射显微镜和傅里叶红外光谱测定蛋白的超微结构变化和内部基团特性。以 天然的马脾铁蛋白为对照, 观察重组铁蛋白与天然铁蛋白的差别。结果显示, 重组铁蛋白富集Pb2+ 和其它7 种重金属离子后蛋白体积大小与重金属离子种类直接相关。重组铁蛋白相对天然铁蛋白来 说在富集不同种类重金属离子后, 除了非特异性酰胺特征峰和蛋白特征峰外, 还出现一些专门富集 某些重金属离子的特异基团, 如:-CH3、-CH2-、-CH-、-NH-、-SO3-、-COOH、-S=S-和-C-S-C 等。 通过细胞实验进一步验证了铁结合蛋白能够通过富集重金属离子Pb2+来保护小鼠成骨前体细胞 MRC3T3-E1, 使细胞的死亡率明显降低(P<0.05). 相似文献
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Photosynthetic activity and antioxidative response of seagrass Thalassia hemprichii to trace metal stress 总被引：1，自引：0，他引：1
This study concerned the accumulation of trace metals in tissues of seagrass (Thalassia hemprichii) exposed to various concentrations of Zn2++, Cd2++, Pb2++ and Cu2++ for 10 d, and the effect of excessive metals on quantum yield (ΔF=Fm'), photosynthetic pigments and antioxidative enzymes like superoxide dismutase (SOD), guaiacol peroxidase (POD) were also examined. Cadmium was the most highly accumulated metal. Meanwhile, high metals levels led to a remarkable breakdown of photosynthetic parameters. Especially, ΔF=Fm', chlorophyll and carotenoid were significantly low during prolonged Cu exposure. Besides, ΔF=Fm' was more severely depressed by Cu and Zn than Pb and Cd. However, T. hemprichii had positive response by increasing the activity of SOD and POD. The results indicate that T. hemprichii is the most sensitive to Cu, and the antioxidative protection mechanisms of T. hemprichii are more efficiently activated to avoid damage of Zn, Cd and Pb stress. Finally, due to the high Cd-accumulation and strong Cd-tolerance capacity, T. hemprichii can be used for phytoremediation in Cd-contaminated areas. 相似文献
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基于自旋-轨道-晶格Hamilton量,应用团簇自洽场方法,研究了双层钙钛矿结构材料K3Cu2F7基态的晶格、磁及轨道结构,发现近孤立的双层的对称破缺和Jahn-Teller晶格畸变使得Cu2+离子在每层内交替占据 z2-x2〉/ z2-y2〉轨道,进而导致双层的层间表现为强的反铁磁耦合,层内为弱的铁磁耦合.强反铁磁耦合导致层间 相似文献
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根据烟尘气溶胶的尺寸分布参数和消光系数,分析了烟尘气溶胶粒子数浓度与传输距离对链路衰减的影响。结合幅值阻尼信道对信道容量、信道保真度及信道误码率进行数值仿真。仿真结果表明,当传输距离为3 km,烟尘气溶胶粒子数浓度由2.1×106 m-3增加到3.2×106 m-3时,链路衰减由0.30 dB增加到0.46 dB,误码率由0.008 7增加到0.012 2。由此可见,烟尘气溶胶对星地量子通信的各项性能均有影响,且影响程度不一。仿真结果可为烟尘气溶胶影响下的量子信号传输提供参考。 相似文献
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过氧化氢(H2O2)等活性氧(ROS)物质因具有绿色高效的特点,在废水处理、杀菌消毒等领域受到研究者广泛关注。利用电催化生成H2O2是一种实时提供活性氧物质的有用方法。然而,目前报道的大多数高性能催化材料都是粉体形式,不便于在实际场景中的应用。因此,制备可直接应用的电极材料显得尤为重要。本研究利用喷涂-热解的制备方法,制备了高活性氧催化活性的氧化炭黑(O−CB)/多孔碳毡电极,通过聚四氟乙烯(PTFE)的修饰优化电极表面的氧气传质,成功制备氧掺杂碳气体扩散电极。研究结果表明,O−CB/PTFE-5 wt%电极具有最高的催化性能,其合成H2O2的速率达27.19 mg·L-1(mg catalyst)-1·cm-1·h-1。海洋典型污损微生物假单胞菌(Pseudomonas sp.)的抗菌实验表明,该电极电催化作用60 min产生的活性氧对Pseudomonas sp.的杀菌率可达到97.69%,作用120 min的杀菌率可达到99.99%。 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
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The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance. 相似文献
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Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding. 相似文献
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Rahul Sharma 《Marine Georesources & Geotechnology》2000,18(3):237-250
Observations on seafloor features from subbottom profiling and seabed photography data show that the undisturbed and natural conditions before the benthic disturbance undergo a substantial change after operation of the disturber. The effects can be seen in the form of deep trenches and grooves, formed by the action of the sleds and the pumping of the sediment along its path, as well as sediment piles on either side of the track. Biological traces such as fecal coils, casts, tubes, burrows, and trails get obliterated in the areas of disturbance and resedimentation. The smooth, uniform nature of the seafloor observed in predisturbance phase shows microtopographic changes in and around the disturbed area as a result of sediment excavation and resettlement. Vertical mixing as well as lateral transport of sediment alter the geological, biological, physical, and chemical conditions on the seafloor, which need to be monitored over time to assess the process and the time taken for restoration of environmental conditions. 相似文献
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Vance P. Vicente 《Marine Ecology》1989,10(2):179-191
Abstract. Long-term changes in the distributional patterns of commercial sponges ( Spongia spp. and Hippospongia spp.) within the West Indian Region indicates that: 1) commercial sponges had a widespread distribution throughout the whole West Indian Region and were ubiquitous in very shallow water until about the first half of the present century; 2) they were fished commercially not only in the traditional northern Caribbean sites (Florida, Gulf of Mexico, Bahamas) but also in the Greater ( e. g. , Hispaniola, Jamaica) and Lesser Antilles; and 3) they became extinct throughout most of the Lesser Antilles ( e. g. , Puerto Rico, Vieques, St. Thomas) sometime during the first half of this century. Mortalities of spongiids within the Antilles were found to differ from other marine mortalities in that: 1) species disappeared from a large region; 2) species vanished from different habitats and depths; and 3) natural populations never recovered. Species richness patterns suggest that commercial sponge genera ( Spongia and Hippospongia ) evolved under slightly cooler elimatic conditions than those found at present, and that these extinctions occurred as a direct or indirect effect of positive thermal anomalies in sea surface and atmospheric temperatures between 1900–1950. The concept that species diversity is stable on a regional scale is questioned. 相似文献