Subtropical meiobenthic nematode communities in Victoria Harbour, Hong Kong   总被引：1，自引：0，他引：1  

Liu XS  Xu WZ  Cheung SG  Shin PK 《Marine pollution bulletin》2008,56(8):1491-1497

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Analyzing biomagnification of metals in different marine food webs using nitrogen isotopes     

Cheung MS  Wang WX 《Marine pollution bulletin》2008,56(12):2082-2088

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香港东北部托罗港湾水环境评价     

蔡宏  余海虎  M. W. L. Cheung 《湖泊科学》1998,10(S1):155-166

Uncontrolled discharges of municipal sewage, agricultural wastes and industrial effluents in the past decades have upset the ecosystems, caused frequent occurrences of red tides, and resulted in a loss of inland and coastal amenity values of the land-locked embayment of Tolo Harbour and the related river systems. This paper provides a review of the established relevant legislations and sewage management facilities for environmental conservation, and the current status of water environment in the Tolo Harbour Water Control Zone.  相似文献   

Hydrodynamic response of a pneumatic floating platform     

K. F. Cheung  A. C. Phadke  D. A. Smith  S. K. Lee  L. H. Seidl 《Ocean Engineering》2000,27(12)

This paper describes a numerical approach to model the dynamic response of a pneumatic floating platform, and the laboratory experiments and parametric study to verify the numerical results. The pneumatic platform is composed of an array of open-bottom vertical cylinders trapping pressurized air that displaces the water. The cylinder diameter is assumed to be small compared to the wavelength and the water inside each cylinder oscillates as a piston. These assumptions simplify the mathematical formulation in that the bottom of the platform can be treated as a continuous surface on which the source distribution method can be applied. In the laboratory experiments, the compressibility and displacement of the trapped air are modeled by a spring and float assembly. The comparison between the numerical and experimental results indicates favorable agreement. The oscillation of the water columns and the overall dynamic characteristics of the platform are illustrated and discussed in the parametric study.  相似文献   

Reconnaissance report on buildings damaged during the Lushan earthquake,April 20, 2013     

Feng Xiong  Lingzhi Xie  Qi Ge  Yuxin Pan  Moe Cheung 《Natural Hazards》2015,76(1):635-650

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The combined effects of oxygen availability and salinity on physiological responses and scope for growth in the green-lipped mussel Perna viridis   总被引：1，自引：0，他引：1  

Wang Y  Hu M  Wong WH  Shin PK  Cheung SG 《Marine pollution bulletin》2011,63(5-12):255-261

Mussels were maintained for 4 weeks under different combinations of dissolved oxygen concentration (1.5, 3.0 and 6.0 mg O2 l(-1)) and salinity (15, 20, 25 and 30) in a 3×4 factorial design experiment. Clearance rate (CR), absorption efficiency (AE), respiration rate (RR) and scope for growth (SFG) decreased with decreasing salinity and dissolved oxygen concentration (DO), while excretion rate (ER) increased with decreasing salinity and increasing DO. The O:N ratio was <10 at salinities of 15 and 20, irrespective of DO levels. SFG was negative in most of the treatments, except for those under 6.0 mg O2 l(-1) or at a salinity of 30 when DO was lower. The results may help explain the distribution pattern of Perna viridis in Hong Kong waters and provide guidelines for mussel culture site selection.  相似文献   

Response of meiofaunal community with special reference to nematodes upon deployment of artificial reefs and cessation of bottom trawling in subtropical waters, Hong Kong     

Liu XS  Xu WZ  Cheung SG  Shin PK 《Marine pollution bulletin》2011,63(5-12):376-384

The response of meiofaunal communities, especially nematodes, upon the deployment of artificial reefs and cessation of bottom trawling at a designated Marine Protected Area (MPA) in Hong Kong was studied through comparison of meiofaunal samples collected inside and outside the MPA. Total organic carbon (TOC), total Kjeldahl nitrogen (TKN), total phosphorus (TP), water content and silt-clay fraction in sediments were also analyzed. The level of TOC and TKN, and total meiofaunal and nematode abundance were significantly lower inside than that outside the MPA. Multivariate analysis also indicated differences in community structure. Biological traits analysis revealed that the proportions of nematodes with a clavate tail shape, longer adult length, stout body shape and k-strategy life history were higher inside than that outside the MPA. Such changes in nematode community structure could be a result of the presence of the artificial reefs and closure of the MPA from bottom trawling.  相似文献   

Stable isotopes as a useful tool for revealing the environmental fate and trophic effect of open-sea-cage fish farm wastes on marine benthic organisms with different feeding guilds     

Wai TC  Leung KM  Wu RS  Shin PK  Cheung SG  Li XY  Lee JH 《Marine pollution bulletin》2011,63(5-12):77-85

Environmental fate of fish farm wastes (FFW) released from an open-sea-cage farm at Kat O, Hong Kong was examined by measuring carbon and nitrogen stable isotope (SI) ratios in selected benthic organisms collected along a 2000 m transect from the farm. Our results showed that FFW significantly influenced the energy utilization profile of consumers near the fish farm. Although nitrogen enrichment effect on δ15N was anticipated in biota near the farm, the predicted patterns did not consistently occur in all feeding guilds. Two species of suspension-feeders, which relied on naturally δ15N-depleted sources, were δ15N-enriched near the fish farm. In contrast, both species of benthic grazer and deposit-feeder, which relied on naturally δ15N-enriched algal sources, were δ15N-depleted under the influence of FFW. The SI signatures of biota can, therefore, serve as feasible biomarkers for FFW discharges only when the trophic structure of the receiving environment is fully elucidated.  相似文献   

Numerical research on drag reduction by ventilated partial cavity based on two-fluid model     

M. Xiang  S.C.P. Cheung  J.Y. Tu  W.H. Zhang 《Ocean Engineering》2011,38(17-18):2023-2032

This paper presents a numerical study on the drag reduction mechanism created by a ventilated partial cavity and its associated effects by the downstream dispersed microbubbles. A semi-empirical approach is introduced to model the discrete interface of the ventilated cavity and its complex gas leakage rate induced by the local turbulent shear stress. Based on the Eulerian–Eulerian two-fluid modeling framework, a population balance approach based on MUltiple-SIze-Group (MUSIG) model is incorporated to simulate the dynamical effects of bubbly flow along the test body. Particular attention is also directed to grasp a better understanding of the size evolution of microbubble and its associated effects on drag reduction. Model predictions are validated against three experimental measurements carried out in a high-speed water tunnel by Schauer (2003) and Wosnik et al. (2005). Close examination of the flow structures, gas void fraction distributions and its resultant density ratio provides valuable insights on the complex physical phenomenon, helping to consolidate idea to maximize the drag reduction for ventilated cavitating vehicles.  相似文献   

Effects of Dietary Vitamin C on the Immune Function of Shrimps, Penaeus chinensis     

Wang Weiqing  LI Aijie  Cheung Siugin 《中国海洋大学学报(英文版)》2002,1(1)

Prepared in this experiment were six groups of diets, i.e. VC0, VC1, VC2, VC3, VC4 and VC5 with the contents of vitamin C (VCmg(100g)-1 diet) of 0, 100, 200, 400, 800, and 1200 respectively. It was found that vitamin C increased the concentrations of immunoglobulin-like (IgG-like, IgA-like and IgM-like) substances in the serum of Penaeus chinensis after a feeding period of 3 weeks. The differences among groups were significant (P＜ 0.01), but there was no difference in the contents of complement3-1ike and complement4-1ike substances in the serum (P ＞0.05). Phenoloxidase (PO) activity in the serum of VC3 group shrimps was higher than that of VC0 and other groups, but no significant difference was observed between VC0 group and other groups. Furthermore, bactericidal activity of the serum to Vibrio parahaemolyticus in shrimps fed with the VC1 diet was higher than that in the other groups (P＜ 0.01), while no difference was demonstrated among all groups for the bactericidal activity to Vibrio alginolyticus (P ＞0.05). It is, therefore, suggested that vitamin C (100-400 mg(100 g) -1 diets) could be used as an immunostimulant of P. chinensis.  相似文献