钛胶海水提铀动力学研究Ⅱ——吸附机理的推断   总被引：1，自引：0，他引：1  

陈松  廖文卓  黄宣宝  唐锦龙 《海洋学报》1981,3(4):571-579

海水提铀机理的研究,已逐渐受到重视,然而,至今研究还不是很深入,观点也各有差别.例如,Keen等[1]认为钛胶从海水中吸附铀是阳离子交换过程,即海水中的铀是UO₂2+离子的形式与钛胶进行交换;尾方升等[2]则倾向于阴离子吸着,即铀是以UO₂(CO₃)₃4-的形式被吸附.我们曾于1973年在海洋局系统的一次会议上提出阳离子给合交换的看法,并在后来的两次专业会议上予以补充发展.张正斌[3]认为是阳离子交换或一价阳离子失水络合.最近崔清晨[4]提出可能是UO₂(OH)₃-的络合吸附.根据几年来的工作,我们仍认为,钛胶从海水中的吸铀机理可能是一种阳离子形式的络合交换过程.  相似文献   

Change of multifractal thermal characteristics in the western Philippine sea upper layer during internal wave-soliton propagation     

Peter C. Chu  Chung-Ping Hsieh 《Journal of Oceanography》2007,63(6):927-939

The upper layer (above 140 m depth) temperature in the western Philippine Sea near Taiwan was sampled using a coastal monitoring buoy (CMB) with 15 attached thermistors during July 28–August 7, 2005. The data were collected every 10 min at 1, 3, 5, 10, 15, and 20 m using the CMB sensors, and every 15 sec at 15 different depths between 25 m and 140 m. Internal waves and solitons were identified from the time-depth plot of the temperature field. Without the internal waves and solitons, the power spectra, structure functions, and singular measures (representing the intermittency) of temperature field satisfy the power law with multi-scale characteristics at all depths. The internal waves do not change the basic characteristics of the multifractal structure. However, the internal solitons change the power exponent of the power spectra drastically, especially in the low wave number domain; they also break down the power law of the structure function and increase the intermittency parameter. The physical mechanisms causing these different effects need to be explored further.  相似文献   

Kuroshio extension variability explored through assimilation of TOPEX/POSEIDON altimeter data into a quasi-geostrophic model     

Yousuke Nishihama  Motoyoshi Ikeda 《Journal of Oceanography》2007,63(6):879-895

Mesoscale features in the eastward extension of the Kuroshio were investigated using assimilation of TOPEX/POSEIDON (T/P) data into a three-layer quasi-geostrophic model. The T/P data exhibited an elongated state of the southern recirculation gyre in 1993–95 and 1997, between whose two periods the gyre had a contracted state in 1995–96. A few stationary eddies were located in the southern gyre during the contracted state. The baroclinic instability, which was indicated by the phase shift from the uppermost-to the lowest-layer anomalies toward the downstream side, was evident near the Kuroshio Extension (KE) path. Since the instability never appeared in the artificial model without bottom topography, the topographic barrier for the eastward flow in the lowest layer was a necessary condition for the instability. The instability synchronized with the transition in the western region of the KE axis from the elongated to the contracted states. This evolution was interpreted as if the baroclinic instability played some part in the KE states and was a trigger for the transition from the elongated to the contracted states.  相似文献   

南海中部和冲绳海槽沉积物中的氨基酸物质   总被引：2，自引：0，他引：2  

郑士龙  唐运千 《海洋学研究》1993,11(2):34-42

本文通过对南海中部和冲绳海槽三个深海沉积物柱状样腐植物质水解氨基酸的研究,试图阐述南海和冲绳海槽沉积物的演化与沉积环境。  相似文献   

Observations of the countercurrent on the inshore side of the Kuroshio northeast of Taiwan   总被引：4，自引：0，他引：4  

Wen-Ssn Chuang  Hsien-Wen Li  T. Y. Tang  Chong-Kung Wu 《Journal of Oceanography》1993,49(5):581-592

Intensive current measurements in the area northeast of Taiwan indicate subsurface, southwestward flow existed between the inshore edge of the Kuroshio and the East China Sea continental slope. At 70 km away from Taiwan, this countercurrent has a mean speed about 30 cm s^–1 at mid-depth. Closer to Taiwan, the flow turns along with the topography, and subjects to sidewall and bottom friction. Both the magnitude and the vertical shear of this countercurrent are comparable with that inferred from hydrographic survey. The wind field features short-period (a few days) fluctuations associated with the cold front passages, however, this is not reflected on the current records. It appears that the countercurrent is fairly steady. Together with similar reversing flow found at places much further to the north, the overall pattern seems to be a general quasi-steady feature along most part of the shelf edge of the East China Sea.  相似文献   

Further evidence for non-reemergence of winter SST anomalies in the North Pacific eastern subtropical mode water area     

Shusaku Sugimoto  Kimio Hanawa 《Journal of Oceanography》2007,63(4):625-635

Following our previous study (Sugimoto and Hanawa, 2005b), we further investigate the reason why reemergence of winter sea surface temperature anomalies does not occur in the North Pacific eastern subtropical mode water (NPESTMW) area, despite its occurrence in the North Pacific subtropical mode water and North Pacific central mode water areas. We use vertical temperature and salinity profiles of the World Ocean Circulation Experiment Hydrographic Program and Argo floats with high vertical and temporal resolution, together with heat flux data through the sea surface. We point out first that one of the causes for non-occurrence of reemergence is that the thickness of NPESTMW is very thin. In addition to this basic cause, two major reasons are found: a vigorous mixing in the lower portion of NPESTMW and less heat input from the atmosphere in the warming season. Since, in the lower portion of NPESTMW and deeper, the stratification is favorable for salt-finger type convection to occur compared with the other mode water areas, vigorous mixing takes place. This is confirmed by both a large Turner Angle there and the existence of staircase structures in vertical temperature and salinity profiles. From the viewpoint of heat input, the NPESTMW area gradually gains heat in the warming season compared with other mode water areas. As a result, NPESTMW cannot be capped so quickly by the shallow summer mixed layer, and water properties of NPESTMW are to be gradually modified, even in the upper portion.  相似文献   

Geomorphological evidence for upslope canyon-forming processes on the northern KwaZulu-Natal shelf,SW Indian Ocean,South Africa     

Andrew N. Green  John A. Goff  Ron Uken 《Geo-Marine Letters》2007,27(6):399-409

A geomorphological and statistical analysis of slope canyons from the northern KwaZulu-Natal continental margin is documented and compared with submarine canyons from the Atlantic margin of the USA. The northern KwaZulu-Natal margin is characterized by increasing upslope relief, concave slope-gradient profiles and features related to upslope growth of the canyon forms. Discounting slope-gradient profile, this morphology is strikingly similar to canyon systems of the New Jersey slope. Several phases of canyon incision indicate that downslope erosion is also an important factor in the evolution of the northern KwaZulu-Natal canyon systems. Despite the strong similarities between the northern KwaZulu-Natal and New Jersey slope-canyon systems, key differences are evident: (1) the concavity of the northern KwaZulu-Natal slope, contrasting with the ∼linear New Jersey slope; (2) the relative isolation of the northern KwaZulu-Natal canyons, rather than the dense clustering of the New Jersey canyons; and (3) the absence of strongly shelf-breaching canyons along the northern KwaZulu-Natal margin. In comparison with the New Jersey margin, we surmise a more youthful stage of canyon evolution, a result of either the canyons themselves being younger or the formative processes being less active. Less complicated patterns of erosion resulting from reduced sediment availability have developed in northern KwaZulu-Natal. The reduction in slope concavity on the New Jersey margin may be the result of grading of the upper slope by intensive headward erosion, a process more subdued—or less evident—on the KwaZulu-Natal margin.  相似文献   

Effects of scattering and resonance on energy dissipation of an internal tide in a narrow shelf     

Yuji Kawamura  Yujiro Kitade 《Journal of Oceanography》2007,63(1):15-25

The effects of scattering and resonance on the energy dissipation of an internal tide were investigated using a two-dimensional model which is a reassembled version of the theoretical generation model devised by Rattray et al. (1969) for internal tide. The basic character of the scattering process at the step bottom was first investigated with a wide shelf model. When the internal wave incited from a deep region (Region II) into the shallow shelf region (Region I), a passing wave into the shallow region, a reflected wave into the deep region, and a beam-like wave, i.e. a scattered wave (SW), emanated at the step bottom. The SW, which consists of the superposition of numerous internal modes, propagated upward/downward into both regions. The general properties of the SW were well expressed around the shelf edge, even in the present model with viscosity effect. The amplitude of the SW decreased dramatically when the depth of the velocity maximum of the incident internal wave in Region II corresponded with the depth of the shelf edge. In the narrow shelf model, where the decay distance of the internal wave in Region I is longer than the shelf width, the incident internal wave reflected at the coast to form a standing wave. When the internal wave in Region I is enhanced by the resonance, the energy of the SW in Region II is also intensified. Furthermore, the energy of the modes in Region II predominated when the velocity maximum is identical to that of the dominant mode in Region I. These results suggest that the spatial scale of shelf region is a very important factor governing the energy dissipation of the internal tide through reflection and scattering in a narrow shelf.  相似文献   

龙口平均海平面变化原因的研究     

毕立海  唐丽美 《海洋预报》1996,13(4):52-55

本文通过对实测海平面高度的对比，发现龙口平均海平面从１９９１年起有明显的升高趋势。作者猜测此乃龙口在码头扩建后有系统下沉所致。  相似文献   

茶皂素对几种鱼类和对虾的毒性研究   总被引：7，自引：0，他引：7  

梁亚全  夏春华  朱全芬  孙修涛  唐丽萍 《海洋科学》1992,16(3):20-25

本研究以茶皂素类作为“清池剂”,试图解决对虾养殖的基础和应用技术问题。试验结果表明:对虾对茶皂素和油茶皂素有较高的耐受力;茶皂素与油茶皂素均具鱼毒活性,油茶皂素则较强。鱼种不同,中毒反应也略有差异;两种茶皂素的鱼毒速度快,在致死浓度时16h内出现中毒死亡,毒性降解也快,浓度为5×10~(-6)时40h后不再引起鱼类中毒。  相似文献