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1.
The solubility of aluminum hydroxide in seawater of 35‰ salinity at pH = 7.4−8.2 and 25°C was determined experimentally for
three samples synthesized in different ways. The solubilities of two phases subjected to ageing and precipitated (a) from
a boiling solution of aluminum sulfate and (b) immediately from seawater at room temperature were a little different and showed
the minimum within pH = 8.05−8.10. The solubility of aluminum hydroxide precipitated from a solution of sulfate aluminum at
room temperature and not subjected to ageing was about twofold at pH∼7.9. The analysis of the pH dependence of the concentration
of dissolved aluminum allows one to suppose that an Al(OH)2+ hydroxo complex is the primary form of the aluminum occurrence in seawater at pH < 8.05, whereas the Al(OH)4− anion is prevailing at pH > 8.10. Electrically neutral Al(OH)30 hydroxocomplexes may be prevailing within the narrow range of pH = 8.05−8.10 and, in general, are of secondary importance. 相似文献
2.
Izvestiya, Atmospheric and Oceanic Physics - On July 5, 2016, NASA’s Juno station began flying around Jupiter in a meridional orbit, having detected eight cyclones near the poles in latitude... 相似文献
3.
A. A. Schreider E. L. Mazo A. A. Bulychev Al. A. Schreider D. A. Gilod M. P. Kulikova 《Oceanology》2011,51(5):866-875
The peculiarities of the crustal structure within the Falkland Basin have been discussed. Maps of the free-air and Bouguer
(2.3 g/cm3) gravity anomalies and their transforms have been made. The complex analysis of the anomalous gravity field has allowed us
to confirm the continental origin of the crust. The zoning of the crust has been performed. The crust is thinned and is enriched
in basic and ultrabasic intrusions. A map demonstrating the distribution of the faults within the studied water area has been
made. A conclusion has been reached about the leading role played by tension processes throughout the evolution of the crust
within the studied water area. 相似文献
4.
A. A. Schreider Al. A. Schreider G. L. Kashintsev J. Galinado-Zaldivar A. Maldonado A. N. Boiko E. I. Evsenko 《Oceanology》2011,51(6):1047-1060
The first map of the acoustic basement and the new map of chrons C1-C5E for the region of the East Scotia mid-ocean ridge
have been made. The analysis of the maps and the calculations have indicated that the sea-floor spreading at the ridge’s flanks
started in its southeast in the interval of chrons C5Er-6An (18.52–20.17 Ma BP). The maximal spreading rate (5.3 cm/year)
was in the interval of chrons C5Bn-C5Br (14.78–15.97 Ma BP). Then, the spreading rate was slow and increased again from 3–6
Ma BP until the present. The spreading in the last 1–2 Ma was accompanied by the propagating of the axes southwards in the
E1, E2, and E4 segments and northwards in the E8 and E9 segments. 相似文献
5.
《Oceanologica Acta》2002,25(5):267-269
This article outlines the background and planning for a South American workshop on marine biodiversity in Concepción, Chile, 28–30 October, 2002. This first CoML/POGO effort in the Southern hemisphere, pursuant to the Sao Paulo declaration began with presentations in all major coastal states and brings together key South American researchers to take advantage of new research concepts emerging from the Census projects. 相似文献
6.
Pituitary gland, or pituitary for short, is characteristic of all vertebrates. As a “master gland” controlling a multitude of important functions in the body, its evolutionary origin has been an object of investigations of evolutionary biology for two centuries. Previous morphological, ultrastructural and immunohistochemical studies suggested the homology of the Hatschek’s pit of amphioxus and vertebrate pituitary. Developmental genetics study showed that the development of Hatschek’s pit and vertebrate pituitary is both subject to regulation by the common genes such as Pit1, Lhx3 and BMP3b. Our recent studies demonstrated that the Hatschek’s pit is able to secrete growth hormone (GH)-like hormone and thyroid-stimulating hormone (TSH)-like hormone that both play functions similar to vertebrate GH and TSH. We thus think that the emergence of Hatschek’s pit represents one of important events during endocrine network evolution, which laid a foundation for the subsequent formation of a hypothalamic-pituitary system in vertebrates. 相似文献
7.
Izvestiya, Atmospheric and Oceanic Physics - The model balance equation of turbulence is represented in the form of the first law of thermodynamics. The forms for entropy are derived with an... 相似文献
8.
NI Kan ZHANG Shengkun QIAN Renjie
Associate Professor School of Naval Architecture Ocean Engineering Shanghai Jiaotong University 《中国海洋工程》1998,(2)
First,Wirsching＇s model,which is widely employed in fatigue reliability anlysis of marine andoffshore structures,is analysed systematically.It is found that the very important random variable △ inWirsching＇s model can not be directly determined from fatigue experiment because of the irreversibility offatigue test,and in fact,what Wirsching studied from testing results is not △ but α of the statistical Miner＇srule.Second,by use of the statistical Miner＇s rule,a modified Wirsching＇s model is proposed.Thirdly andmore importantly,based on the two-dimensional probabilistic Miner＇s rule,a new model is established forfatigue reliability analysis of structural components subjected to specified cyclic loading of variableamplitude or stochastic time history.In the end,an example is presented,from which it will be seen thatthis new model is very convenient to use and feasible to engineering practice. 相似文献
9.
《Marine Policy》2014
The primary goal of Australia’s National Representative System of Marine Protected Areas (NRSMPA) is to establish a comprehensive, adequate and representative system of MPAs. This study identifies a glaring contradiction to this policy. The provinces of Christmas and Cocos Islands are among the most unique and threatened marine bioregions in Australia, yet receive no protection from the NRSMPA. The lack of protection appears to be due to difficulties with multiple governance arrangements and other political priorities. These issues have already caused biodiversity loss in the terrestrial environment of these bioregions. The Australian Government must include the Christmas and Cocos provinces in the NRSMPA otherwise it risks irreversible loss of marine biodiversity in these unique bioregions. 相似文献
10.
N. A. Rimskii-Korsakov V. N. Korotaev V. V. Ivanov A. A. Pronin N. A. Demidenko 《Oceanology》2013,53(5):630-638
New data on the Onega River estuary’s hydrological and morpholithodynamic regimes are presented. The river’s bottom structure and soil lithology are described on the basis of field sonar survey materials. Proceeding from the analysis of the hydrographic maps, the dynamics of the Onega River’s mouth bar is tracked over the period of 1830–2000. 相似文献
11.
《Marine Policy》2013
Multi-species fisheries are complex to manage and the ability to develop an appropriate governance structure is often seriously impeded because trading between sustainability objectives at the species level, economic objectives at the fleet level, and social objectives at the community scale, is complex. Many of these fisheries also tend to have a mix of information, with stock assessments available for some species and almost no information on other species. The fleets themselves comprise fishers from small family enterprises to large vertically integrated businesses. The Queensland trawl fishery in Australia is used as a case study for this kind of fishery. It has the added complexity that a large part of the fishery is within a World Heritage Area, the Great Barrier Reef Marine Park, which is managed by an agency of the Australian Commonwealth Government whereas the fishery itself is managed by the Queensland State Government. A stakeholder elicitation process was used to develop social, governance, economic and ecological objectives, and then weight the relative importance of these. An expert group was used to develop different governance strawmen (or management strategies) and these were assessed by a group of industry stakeholders and experts using multi-criteria decision analysis techniques against the different objectives. One strawman clearly provided the best overall set of outcomes given the multiple objectives, but was not optimal in terms of every objective, demonstrating that even the “best” strawman may be less than perfect. 相似文献
12.
The global VDM database, which was later supplemented by new determinations published in the world literature (a total of
3194 determinations), is used as the basis for addressing the VDM behavior in the Phanerozoic (0–542 Ma) and up to 580 Ma.
The results revealed a positive linear trend to higher VDM values from 3.5 × l022 Am2 to 5.7 × l022 Am2. Against this background, fluctuations of the mean VDMs occur with a periodicity of about 40 Myr. In the Phanerozoic, prominent
minima of the intensity are found in the time intervals of 510–520, 420–460, 340–370, 290–300, 240–270, 190–210, 165–140 Ma
(chrons M17–M43), 130–120 Ma (chrons M2–M10), 100–110 Ma (chron C34), 75–85 Ma (chrons C33 and the beginning of chron C34),
70–60 Ma (chrons C31–C27), and 40–15 Ma (chrons C18–C5AD). The distribution of the VDMs appears to reflect the paleomagnetic
field behavior and may be taken into account in a magnetization model for the reversely magnetized oceanic crust. 相似文献
13.
Experimental Investigation of the Decay from A Ship’s Propeller 总被引：1，自引：0，他引：1
In the present study,an experimental investigation of the decay of the maximum velocity and its turbulent characteristics behind a ship propeller,in "bollard pull" condition(zero speed of advance),is reported.Velocity measurements were performed in laboratory by use of a Laser Doppler Anemometry(LDA) measurement system.Earlier researchers described that the maximum axial velocity is constant at the initial stage of a ship’s propeller jet(Fuehrer and Rmisch,1977;Blaauw and van de Kaa,1978;Berger et al.,1981;Verhey,1983) as reported in a pure water jet(Albertson et al.,1950;Lee et al.,2002;Dai,2005),but a number of researchers disagreed with the constant velocity assumption.The present study found that the maximum axial velocity decays in the zone of flow establishment and the zone of established flow with different rates.The investigation provides an insight into the decays of both the maximum velocity and the maximum turbulent fluctuation in axial,tangential and radial components and the decay of the maximum turbulent kinetic energy.Empirical equations are proposed to allow coastal engineers to estimate the jet characteristics from a ship’s propeller. 相似文献
14.
《Marine Policy》1999,23(2):177-190
This paper has two aims. First, New Zealand’s quota management system is analysed using a simple analytical economic model. Second, the paper describes how the system has evolved in response to pressures since implementation. The quota management system has provided a remarkably robust platform for addressing fisheries management problems during its first ten years of operation. It also provided the government with an instrument for settling Maori fishing claims. In 1996, the unsubsidised New Zealand fishing industry exported most of its harvest to highly competitive international markets. The paper concludes with a discussion of contemporary challenges. 相似文献
15.
Sea area is an important area of oil and gas exploration in China. It has been found that China’s sea area mainly consists of coal type oil and gas, and the exploration of coal-bearing series source rocks has become an important part of oil and gas exploration there. Through years of comprehensive geological research in China’s sea area, it has been revealed that it has undergone multiple occurrences of tectonic opening and closing movements in varying degrees in the Paleogene, forming 26 Cenozoic sedimentary basins of various types, such as active continental margin, passive continental margin, transitional continental margin and drift rift basins. In the present study, it is observed for the first time that coal type source rocks are mainly developed in 14 continental margin basins in China’s sea area, revealing that a very large C-shaped coal-bearing basin group developed there in the Cenozoic. Next, based on the coupling analysis of paleoclimate, paleobotany, paleogeography and paleostructure, it is observed that there are five coal-forming periods in China’s sea area, namely the Paleocene, Eocene, early Oligocene, late Oligocene and Miocene-Pliocene, and the coal-forming age is gradually new from north to south. It is also found that the coal seams in the sea area are mainly developed in three coal-forming environments in Cenozoic, namely delta, fan delta and tidal flat-lagoon. The coal seams developed in different environments are characterized by thin thickness, many layers and poor stability. However, the coal-bearing series source rocks in China’s sea area have a wide distribution range, very high thickness and large amount, thus forming a material basis for the formation of rich coal type oil and gas. 相似文献
16.
GONG Haidong* ZHANG Zhengbin LIU Chunying LIU Liansheng.Institute of Marine Chemistry College of Chemistry Chemical Engineering Ocean University of China Qingdao China 《海洋学报(英文版)》2006,(1)
1 Introduction It is well established that trace metals can exist in the environment for a long time, which will affect the ecosystem greatly (Baeyens et al., 1998; Kremling, 1983; Rozen et al., 2000). The transport, bioavailabili- ty, fate and toxicity o… 相似文献
17.
Trenching depth calculation of traveling jet is a very important field in both pipeline burying and dredging engineering. The trenching ability of a noncontact control flow jet trencher was predicted by experimental method according to the geometry similarity. In the test, the jet pressure, the shear strength of clay, and the translational speed of nozzle were the same with the design parameters, while the nozzle was a reduced scale model. The trenching depth was found about seven to nine times of the nozzle’s diameter. The width of the trench was about four times of the nozzle’s diameter. Based on the test results the noncontact jet trencher was produced and succeeded in practical usage. 相似文献
18.
《Marine Policy》1998,22(3):229-234
The 1972 United Nations Conference on the Human Environment (Stockholm, UN Conference, 1972) outlined a ‘masterplan’ linking environmental assessment, environmental management and supporting measures as basic and inseparable elements of environmental actions plans. It also indicated the advantages of a regional approach in contributing to the solution of global problems. The Regional Seas Programme of UNEP (United Nations Environment Programme) was subsequently initiated in 1974 (UN General Assembly, 1972). Development of UNEP’s Regional Seas Programme demonstrated that the basic concepts formulated at Stockholm can effectively foster regional cooperation among interested States, and may benefit from the support of the United Nations system as a whole.The present Regional Seas Programme includes fourteen regions, comprising over 140 coastal States. It was conceived as an action-oriented programme encompassing a comprehensive, trans-sectoral approach to marine and coastal areas and to environmental problems, considering not only the consequences, but also the causes of environmental degradation. Each Regional Seas Programme is based on the needs of the region concerned. The Regional Seas Programmes promote the parallel development of regional legal agreements, and of action-oriented programme activities, as embodied in the action plans. The overall strategy to be followed, as defined by UNEP’s Governing Council (UNEP, 1974) is:
- 1. Promotion of international and regional conventions, guidelines and actions for the control of marine pollution and the protection and management of aquatic resources.
- 2. Assessment of the state of marine pollution, pollution sources and trends, and of the impact of pollution on human health, marine ecosystems and amenities.
- 3. Coordination of efforts with regard to environmental aspects of the protection, development and management of marine and coastal resources.
- 4. Support for education and training efforts to facilitate the full participation of developing countries in the protection, development and management of marine and coastal resources.
19.
《Marine Policy》2013
This study proposes a hybrid operational model to manage marine activities. This approach combines cost-benefit analysis (CBA), the analytic hierarchy process (AHP), and the Dempster–Shafer theory (DST), and retains the advantages of CBA as well as facilitating the incorporation of incomplete information into the evaluation process. A particular advantage of this hybrid approach is that it can synthesize evaluation results into an easily understood unit: namely, utility. Conflicts between marine resource users (user–user conflicts) and between users and marine environment (user-environment conflicts) can easily be evaluated using this hybrid operational model. A sea use management system is proposed, which incorporates a permitting process and elements of marine spatial planning (MSP). In the proposed system, marine activities are grouped into three clusters based on their potential environmental impacts and exclusive use, then assigned to competent authorities, a panel of experts or government agencies for review and permit approval. This study suggests that the central and local governments share responsibility for approving permits for marine activities. More importantly, it suggests that the integration of marine activities needs to be handled by the central government. A numerical example is used to illustrate the application of the hybrid operational model. 相似文献
20.
《African Journal of Marine Science》2013,35(3):291-304
Studies to understand local-scale patterns in the recruitment of juvenile coral-reef fishes within the western Indian Ocean (WIO) region are few, yet such knowledge is important in fisheries management. Underwater visual census surveys were conducted at five shallow fringing-lagoon reef sites along the Kenyan coast, between June 2012 and March 2016, to quantify patterns in the abundance of new recruits and juveniles. Recruitment was observed year-round, with a consistent pronounced seasonal peak in recruit densities and species richness during December to April of each year, which was strongly correlated with high sea temperatures. Annual variations in recruitment were also observed, with a higher recruitment peak in 2013 as compared with in other years. A total of 112 species belonging to 19 families were identified, dominated by species belonging to the Pomacentridae, Labridae and Apogonidae, which altogether represented 91% of the total number of recruits recorded. The species with the largest number of recruits (Chromis viridis, Thalassoma hebraicum and Gomphosus caeruleus) showed evidence of year-round recruitment, although the timing of recruitment peaks was not consistent. Multivariate analysis of the species composition separated mainland from offshore fringing-reef sites, and also revealed strong habitat associations, pointing towards increasing recruit abundance with increasing live hard-coral cover and rugosity. Live hard-coral cover, which constituted an average of 21%, was associated with 63% of the total number of recruits recorded. This study contributes new insight into local-scale patterns of juvenile reef-fish recruitment in Kenya and the WIO region, and demonstrates the important nursery function of shallow fringing-lagoon reefs. 相似文献