A large excess of 210Po in the overlying water of the Zhubi Coral Reef flat, in the South China Sea

The temporal variability of ²¹⁰Po and ²¹⁰Pb was examined in the overlying water of the Zhubi Coral Reef flat to detect nutrient-like behavior of ²¹⁰Po. Different mechanisms influencing their geochemical behaviors were observed. Excess ²¹⁰Po relative to ²¹⁰Pb revealed an additional input of ²¹⁰Po other than in situ production from ²¹⁰Pb. The ²¹⁰Po input comes from the reef flat sediment through diffusion. The diffusion contributes 62% of the total ²¹⁰Po. This diffusion of ²¹⁰Po directly highlights its nutrient-like behavior. No input, but the slight removal, of ²¹⁰Pb was observed. Fractionation factors indicate that particulate matter prefers to adsorb ²¹⁰Po rather than ²¹⁰Pb. In combination with particulate composition, ²¹⁰Po diffusion was closely related to organic matter. These results reveal that ²¹⁰Po might be a potential tracer for quantifying nutrient recycling in the Coral Reef system.     

Hepatic histopathology in two populations of the mummichog,Fundulus heteroclitus

The pollution-tolerant mummichog, Fundulus heteroclitus, inhabits a heavily contaminated estuary, Piles Creek (PC), in Linden, NJ. PC contaminants include PAHs, PCBs and many metals, including high Hg and Pb. PC mummichog livers and kidneys were compared with those from a pristine estuary in Tuckerton (TK), NJ, by standard histopathological methods, with quantification by computerized image analysis. PC livers had > 2 x the lipid ratios of TK livers. Cell sizes and shapes were not different between populations. TK livers had a 25% incidence of basophilic areas and an age-related 30% incidence of macrophage aggregates; PC livers had none of these lesions. PC livers had a 100% incidence of necrotic foci, compared with 55% of TK livers. Inflammation was noted in 50% of TK livers but only 27% of PC livers. Curiously, the TK livers had a 45% incidence of metacercarial cysts of a digenetic trematode, while none were found in the PC livers. The TK focal necrosis and macrophage aggregates coincided with parasite infestation. There were no observed kidney lesions in either population. Positive biomarkers in this species thus included high hepatic lipid content, possibly necrosis, but no other lesions. The lack of trematode cysts in PC livers may reflect the lack of an intermediate host in this low biodiversity estuary.     

浅部开采地面塌陷对井下危害及防治

全面调查了某矿浅部开采地面塌陷坑的形成条件及存在状态，采用模糊聚类分析方法对地面塌陷坑进行了科学的分类，分析了塌陷特征及其对井下危害程度，提出了消除塌陷坑对井下危害、恢复矿区生态环境的防治目标及具体原则，研制出地面塌陷坑治理的四种方案，即①排除积水，构筑隔水层；②煤矸石充填塌陷坑复垦土地；③利用塌陷坑发展养殖；④因地制宜，综合治理。通过方案的实施，彻底消除了塌陷坑对井下的危害，地面生态环境得以恢复，取得了理想的治理效果和经济社会效益。     

河北平原浅层地下水地球化学演化模拟

反应路径模拟技术是近十几年发展起来的定量研究地下水地球化学演化的重要方法。文中讨论了反应路径模拟与质量平衡模拟的差异，提出了对复杂水流系统采取分段模拟，以及对浅层成水形成的主要作用即蒸发浓缩作用和海侵的影响采用土壤盐类综合体的溶解来表征的处理方法，论述了研究区浅层地下水的地球化学演化过程。     

潜江凹陷古盐湖水文化学面貌的再造

古盐湖水文化学面貌的再造是研究地下卤水起源和演化问题的基础。配方从潜江凹陷古盐湖水水质的形成特点,演化和古盐度的计算,再造了潜江凹陷古盐湖的水文化学面貌。在古盐度的计算过程中,采用了调参的方法解决公式的应用问题,所取得的盐度数据对了解古盐湖水质演化的概貌具有一定意义。     

测绘生产单位技术队伍的合理结构--专科与中专毕业生在测绘生产单位的作用与地位

介绍测绘生产单位的基本任务,测绘技术队伍形成的基本规律,专科与中专毕业生在测绘生产单位的作用与地位,以及建设一支又红又专测绘队伍应采用的措施。     

Relative risk assessment of cruise ships biosolids disposal alternatives

A relative risk assessment of biosolids disposal alternatives for cruise ships is presented in this paper. The area of study encompasses islands and marine waters of the Caribbean Sea. The objective was to evaluate relative human health and ecological risks of (a) dewatering/incineration, (b) landing the solids for disposal, considering that in some countries land-disposed solids might be discharged in the near-shore environment untreated, and (c) deep ocean disposal. Input to the Bayesian assessment consisted of professional judgment based on available literature and modeling information, data on constituent concentrations in cruise ship biosolids, and simulations of constituent concentrations in Caribbean waters assuming ocean disposal. Results indicate that human health and ecological risks associated with land disposal and shallow ocean disposal are higher than those of the deep ocean disposal and incineration. For incineration, predicted ecological impacts were lower relative to deep ocean disposal before considering potential impacts of carbon emissions.     

Carbon and nitrogen cycling in the Zhubi coral reef lagoon of the South China Sea as revealed by 210Po and 210Pb

The radionuclides (210)Po and (210)Pb were examined to trace the cycling of particulate organic carbon (POC) and particulate organic nitrogen (PON) in the Zhubi coral reef lagoon. The net export flux of POC to the open sea is 14 mg Cm(-2) d(-1). However, the net exchange of PON has not yet been observed. On average, the vertical export fluxes in the lagoon of POC and PON, as derived from (210)Po/(210)Pb disequilibria, are 43 mg Cm(-2) d(-1) and 13.8 mg Nm(-2) d(-1), respectively. The deficit of (210)Po relative to (210)Pb in particulate matter provides evidence for the degradation of particulate organic matter. According to the mass balance budgets, 310 mg Cm(-2) d(-1) and 121 mg Nm(-2) d(-1) were recycled into dissolved fractions. Based on a first-order kinetics model, the degradation rate constants of POC and PON are 0.28 and 0.30 m(-1), respectively. Thus, (210)Po and (210)Pb can quantify the cycling of carbon and nitrogen in this coral lagoon.