Current status and historical trends of organochlorine pesticides in the ecosystem of Deep Bay, South China

To characterize the current status and historical trends in organochlorine pesticides (OCPs) contamination in Deep Bay, an important water body between Hong Kong and mainland China with a Ramsar mangrove wetland (Maipo), samples from seawater, suspended particulate matter (SPM), surface sediment, sediment core and fish were collected to determine the OCPs concentrations. Sediment core dating was accomplished using the ²¹⁰Pb method. The average concentrations of DDTs, HCHs and chlordanes in water were 1.96, 0.71, 0.81 ng l⁻¹, while in SPM were 36.5, 2.5, 35.7 ng g⁻¹ dry weight, in surface sediment were 20.2, 0.50, 2.4 ng g⁻¹ dry weight, and in fish were 125.4, 0.43, 13.1 ng g⁻¹ wet weight, respectively. DDTs concentrations in various matrices of Deep Bay were intermediate compared with those in other areas. Temporal trends of the targeted OCPs levels in sediment core generally increased from 1948 to 2004, with the highest levels in top or sub-surface sediment. Both DDT composition and historical trends indicated an ongoing fresh DDT input. A positive relationship between the bioconcentration factor (BCF) of target chemicals and the corresponding octanol–water partition coefficient (K_ow), and between the biota-sediment accumulation factors (BSAF) and the K_ow were observed in the Bay. The risk assessment indicated that there were potential ecological and human health risks for the target OCPs in Deep Bay.     

Mortality risk of a future heat event across a subtropical city: implications for community planning and health policy

Natural Hazards - In this study, we applied the Weather Research and Forecasting model to project 2050 urban and rural temperature. We applied a time-stratified analysis to compare it with...     

The formation mechanisms of turbidity maximum in the Pearl River estuary, China

The formation and dynamics of turbidity maxima (TM) in the Pearl River estuary (PRE) are not well understood but the existence of TM in the estuary have great potential engineering and environmental impacts. Based on the measurements of two large-scale field surveys conducted in the wet season of 1978 (July of 1978) and the dry season of 1979 (March of 1979), the existence and seasonal variations of TM in the PRE focusing on the two major natural navigation channels have been studied. The sediment transport fluxes over two consecutive tidal cycles have been analyzed in detail. The analysis results reveal that the formation mechanisms of TM in the estuary are rather complex. In general, gravitational circulation, tidal trapping, and sediment resuspension and deposition processes are the primary TM formation mechanisms in the PRE. The clockwise back flow pattern around Lingding Island also leads to the formation of TM in the West channel of the PRE. The occurrence of TM far upstream of the salt water wedge is the result of the complex hydrodynamic and sediment transport processes generated by the runoff of the major rivers.     

An improvement in cumulus parameterization by invoking outgoing longwave radiation

Summary The Kuo-type cumulus parameterization and rainfall rate scheme is extended by including the outgoing longwave radiation (OLR), the local time rate of change of OLR, and the horizontal Laplacian of OLR to include the additional source of mesoscale moisture supply. The extended scheme remains simple and efficient. A series of 5-day forecasts of the 1979 monsoon for the tropical belt between the Arabian Sea and the western Pacific Ocean show improvement in the 3-day forecast in the daily accumulated precipitation in both the amount and location. Further RMS error analyses indicate that using OLR and the Laplacian of OLR also produces a significant improvement in a 3-day forecast. Additional tests of the extended scheme for the 1987 and 1988 monsoons produced consistent and characteristic areal rainfall rates in the tropics. The improvement in the OLR model forecasts is attributed to the improved skill of OLR forecast in the forecast model as the RMS errors for 5 consecutive days in the 6 experimental forecasts are smaller than those of the 3 control forecasts.With 12 Figures     

The Current Situation in Seismological Research in Negara Brunei Darussalam

In this paper,the regional geologic setting and seismic hazard of Brunei Darussalam are outlined.The earthquake monitoring system and to ability to recored,process and analyze seismic events in surrounding areas are described,and some results of epicenter determinations by the monitoring system are given(Appendices I and Ⅱ）。     

The breakup of marine boundary-layer clouds over an inhomogeneous sea surface temperature field

This numerical study examines the breakup of marine atmospheric boundary-layer (MABL) clouds through various physical processes over an inhomogeneous sea surface temperature (SST) field. Three regimes are identified under which the cloud layer will break up. (A) advection of drier air into the MABL for the California case. (B) daytime absorption of solar radiation, occurring most easily over the cold water. (C) mesoscale fluctuations in the flow, producing holes in the cloud layer.The budget study of these three situations concludes that large-scale subsidence, solar radiation, local mesoscale advection, and inhomogeneous surface fluxes cannot be neglected in modeling cloud breakup. This study also confirms the belief that the mixing process alone induced by evaporative entrainment is generally insufficient to predict the breakup of the cloud layer.Sections of this paper are based on an extended abstract by the author and Dr. Steven Stage for the Ninth Symposium on Turbulence and Diffusion held at Riso, Denmark, 1990.     

甲壳胺人工皮—CHIMEHERB治疗不同类型创面初步结果

本文报告了1989年1月至12月使用甲壳胺人工皮治疗94例不同类型创面,其中手部创伤66例,烧伤5例,其它创面17例。结果断层皮肤损伤愈合良好,小面积全层皮肤损伤愈合后有少量疤痕形成,在手外伤中,以指端损伤效果较好,采用此疗法,方法简单,易于推广。     

上海浦东发展路径研究

浦东开发在我国30年经济改革中具有里程碑式的意义。在分析浦东不同发展阶段主要开发内容与特征的基础上,归纳出了浦东区域发展路径的5个特点:实施外源型产业战略与设立较高产业进入门槛、拓展融资渠道与建立创投基金、重视功能分区与发挥产业集聚效益、注重政策引导与政策适时更新、建立高效政府与扶持中介服务机构。从提升浦东可持续发展能力的角度,指出了应该着力解决浦东外资依赖严重、自主创新能力不强等问题,以提升浦东产业的核心竞争力。     

Field observations on correlation of fatty acid profiles between suspended particulate matter and green-lipped mussels in subtropical waters of Hong Kong

By analysis of the fatty acid profiles in mussel tissues and suspended particulate matter (SPM) in water, the present study showed a significant relationship of the trophic linkage between mussels and the SPM. At seven locations from inner to outer areas along the eutrophic Tolo Harbour and Tolo Channel, Hong Kong, the composition (as percentage of total fatty acids) of both monoenoic and polyunsaturated fatty acids in the tissues of green-lipped mussels Perna viridis and SPM in water had significant correlation (p<0.01). In particular, the composition of docosahexaenoic acid (DHA, 22:6n3) (as percentage of total fatty acids) in mussel tissues was statistically correlated with that in SPM (p<0.01), implying that mussels incorporate DHA, the biomarker of dinoflagellates. Principal component analysis further demonstrated that the fatty acid profiles of SPM were different among locations in the harbour, mid and outer channel of the study area, so were the mussel tissue fatty acid profiles. Cluster analysis of phytoplankton data also revealed the dominance of diatoms in the inner harbour and channel areas, whereas dinoflagellates were abundant in the outer channel waters. The possible implications of using benthic suspension feeders such as green-lipped mussels P. viridis for controlling phytoplankton abundance in coastal waters are discussed.     

The Regionalization of Chinese Business Networks: A Study of Singaporean Firms in Hainan,China

This paper examines the central role of social and political institutions behind motivations and strategies of ethnic Chinese Singaporean investment in Hainan, China. Drawing upon 22 case studies of Singaporean firms in Hainan, we show that Singaporean investment in Hainan is embedded in Chinese business networks and their associated institutions. At the personal level, direct investments are largely motivated by the cultural attachments of Singaporean Hainanese to Hainan. Their small‐ and medium‐sized joint ventures largely reflect the characteristics of ethnically‐based Chinese business networks that stress connections, or guanxi. Similarly, the influence of social organizations (e.g., clan associations) and government institutions (e.g., public and quasi‐public agencies) on Singaporean investment strategies in Hainan reveals the significance of ongoing social relations institutionalized at the broader societal level.