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1.
厦门外来植物入侵风险评价指标体系的建立——以互花米草入侵风险评价为例 总被引：4，自引：0，他引：4
本文结合前人在生物入侵风险评价方面的研究成果，针对厦门市外来植物入侵现状，建立了厦门地区外来植物入侵风险评价指标体系及评价方法．该指标体系由6个一级指标，17个二级指标构成．通过文献资料分析、实地调研等手段，以厦门海域主要的入侵植物互花米草为例，评价其风险分值为85，入侵风险等级为“不可接受”．此外，本文还选取其他19种外来植物进行了风险评价与风险等级划分，结果表明。互花米草在20种外来植物中风险分值列第三，评价结果与其危害现状相符． 相似文献
2.
第四纪气候事件的孢粉记录 总被引：6，自引：0，他引：6
通过总结我国不同区域现有孢粉资料，发现第四纪孢粉植物群的演化序列中明显地存在与演化趋势和周期不符的孢粉植物群事件。归纳起来有三种类型：延续时间约万年的孢粉植物群突变事件；延续时间数千年的孢粉植物群贫乏事件和延续时间几百年的孢粉植物群颤动事件。突变事件有４起：Ｂｅｔｕｌａ－Ａｒｔｅｍｉｓｉａ事件（２．５ＭａＢ．Ｐ．）；Ａｒｔｅｍｉｓｉａ－Ｇｒａｍｉｎｅａｅ事件（１．４ＭａＢ．Ｐ．）；Ｅｐｈｅｄｒａ－ 相似文献
3.
红外线和植物生长物质对紫球藻生长及代谢的影响 总被引：4，自引：0，他引：4
特定红外辐射能促进紫球藻Ｐｏｒｐｈｙｒｉｄｉｕｍ ｐｕｒｐａｒｅｕｍ生长;植物生长物质,即吲哚丁酸（ＩＢＡ）、三十烷醇（ＴＡ）及其复配形式对紫球藻的光合作用、呼吸作用、生长繁殖等生理过程皆有促进作用;正交实验结果表明,植物生长物质最佳组合为ＴＡ１．０ｕｇ．ｍｌ＾－１,ＩＢＡ０．１ｕｇ．ｍｌ＾－１（１０：１）。 相似文献
4.
在那里．终年没有阳光、氧气非常稀薄、水压巨大、没有任伺海洋植物．生存条件相当恶劣．生物对此作出各种适应．最终的结果是．这里的海洋生物几乎全部是捕食高手，而它们从形状到习性，奇特性远远超出了所有科学家的想像。 相似文献
5.
中国4Ma来孢粉植物群气候的多重旋回模型 总被引：4，自引：0，他引：4
本文应用频谱分析方法，研究了近４Ｍａ来的孢粉植物群气候波动，确定存在准１２０，３０（或４０），１０（或６）万年的周期。依据孢粉植物群的时空分布建立了多重气候旋回模型，该模型将４Ｍａ来气候划分为３个１．２Ｍａ的气候幕，１２个０．３（或０．４）Ｍａ的气候期，４８个０．１（或０．０６）Ｍａ的气候段。并且讨论了模型与自然环境演变及季风气候兴衰的关系。指出在冬、夏季风交替活动过程中，夏季风兴盛于２．０－１．８Ｍａ及０．８－０．２Ｍａ两个时期；冬季风活跃于２．５－２．３Ｍａ及１．２－０．８Ｍａ两个时期。 相似文献
6.
利用稳定碳同位索比值作为古气候的指示剂．取决于C3和C4植物型对生态环境的不同要求，它们的^13C／^12C之比差异较大．C3和C4植物按照各自固碳的光合作用途径，二者分别具有-26‰--28‰和-11‰--13‰的δ^13C值．这也说明它们对生态环境的不同选择． 相似文献
7.
硼对海带雌配子体生长的影响 总被引：1，自引：0，他引：1
硼对高等植物生长的影响，已有不少的研究．有人认为它是植物生长所必需的元素，有人不同意这个意见。硼对海藻的效应，研究的不多．McBride等的观察指出，硼对小球藻的生长没有什么影响。Lewin的实验表明，硼对硅藻的生长是必需的．Nasr等的观察指出， 相似文献
8.
此项目采用实验（现场、室内）方法研究海岸（河口）高潮滩盐沼泥沙过程 ,即波浪、潮流、海岸盐生植物、细颗粒悬沙和淤泥质底床的相互作用。（１）高潮滩盐沼盐生植物的野外调查 :海岸盐生植物的属种、高度、大小、密度 ;（２）高潮滩盐沼边界层水流结构的现场实验观测 :ａ．潮流水位、流速、紊动的野外现场观测 ;ｂ．波浪衰减的观测 ;（３）高潮滩盐沼细颗粒悬沙浓度的现场观测 ;（４）高潮滩盐沼地区长期、短期细颗粒泥沙堆积和侵蚀速率的现场观测 ;（５）海岸盐生植物作用下波浪、潮流边界层的室内实验研究 ;（６）海岸盐生植物作用下细… 相似文献
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海蓬子种子营养成分分析及制备共轭亚油酸的研究 总被引：7，自引：0，他引：7
分析了盐生植物——海蓬子种子的营养成分，并利用其种子油制备共轭亚油酸。研究结果表明：海蓬子种子蛋白质含量为42．59％，高于大豆和其它蛋白质植物；氨基酸组分较齐全，优于鸡蛋蛋白。种子油不饱和脂肪酸含量高，为89．77％，其中亚油酸为73．63％，组成类似红花油，有很高的营养保健功能。用种子油制备共轭亚油酸，亚油酸转化为共轭亚油酸的转化率达到86．07％，共轭亚油酸含量将近70％，海蓬子种子油可制成优质食用油，也可作为制备共轭亚油酸的原料。 相似文献
11.
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
12.
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
13.
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
16.
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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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
19.
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
20.
The behaviour of an axially pre-loaded cylindrical member of an offshore structure, hit by a supply ship, has been investigated. The effects of axial pre-loading on the dynamic properties of members, the extent of damage and propagation of dynamic instability in the tubular members have also been investigated. Numerical models have been validated using available experimental data from the literature although these are mostly static with no pre-loading. Axial pre-loading was found to change the dynamic characteristics of some cylindrical members quite dramatically while it had no significant effect on others. The study examined whether there was any change in the behaviour between local and global modes when the loading was dynamic rather than static. The effect of damping on the dynamic instability of axially pre-loaded tubes under lateral dynamic loads was also studied. It was observed that for some geometries the quasi-static response can be used to define the boundary between bounded and unbounded dynamic responses. The main contribution of this study, compared with previous investigations reported in the literature, is that both pre-loading and dynamic effects have been included. 相似文献