从人为放射性核素--(137)Cs看福岛核事故对中国海的影响

2011年4~6月在中国海采集了海水样品,用低本底能谱测定了海水137CS活度,旨在评估福岛核事故对中国海、特别是对东海的影响.在观测期,中国海137CS活度为0.75±0.07~1.43±0.08bQM3,平均值为1.12±0.08bQM3.东海表层137CS水平分布在内陆架最高,沿岸和外陆架均较低;在垂直分布上,137CS在表层最高,并呈随深度逐渐降低.这种分布特征主要受控于137CS大气沉降输入以及随后的决定于不同水团间的混合效应.针对东海而言,137CS在水柱中的储量为93bQM2,大气输入通量为5.4~42.9MbQM2d1,平均为32.2MbQM2d1,在东海的停留时间为45~95d,平均为66d;总体而言,福岛核事故对东海137CS的影响小于切尔诺贝利事故,其输入的总量对东海的影响不显著.国家重点基础研究发展计划(2009CB421200)资

中国邻近边缘海碳通量研究现状与展望

集成分析了南海、东黄渤海等中国邻近边缘海（简称中国边缘海）海-气界面CO2通量及其所表征的CO2源汇格局,简析海-气CO2通量的主要控制因素;总结了河-海界面、边缘海与大洋的交换界面及输出真光层的碳通量,进而初步构架了简化的中国边缘海碳收支;并与世界其他陆架边缘海碳的源汇格局和通量作了比对,最后对边缘海碳循环研究进行了展望.从周年尺度上看,中国边缘海是大气CO2的源,全年向大气的释放量为（9.5±53）Tg C;河流经过河口输送至中国边缘海的总碳量为（59.6±6.4）Tg Ca-1;中国境内河口释放CO2的总量为（0.74±0.02）Tg Ca-1;西太平洋每年输入中国边缘海的总碳量为2.5Pg Ca-1,可见,西北太平洋输入中国边缘海的碳通量巨大.中国边缘海上层海洋颗粒有机碳输出通量为（240±80）Tg Ca-1.国家自然科学基金项目(批准号:91328202、91428308);;科技部重大科学研究计划项目(编号:2015CB954001);;国家海洋局海洋公益项目(编号:201505003-3);;全球变化专项项目(编号:GASI-03-01-02-02)资

Fluorescence measurement of tryptophan content in microalgae

建立了微藻中色氨酸的荧光分析方法。以NaOH为水解液水解微藻,在激发波长225nm,发射波长350 nm处测定色氨酸的荧光强度。方法线性范围0~0.07 mg/L,检测限为0.003 mg/L,回收率90%~100.1%。此法快速、简便、灵敏度高。This paper set up a procedure of fluorescence method to measure tryptophan in microalgae.NaOH containing 0.5% soluble starch was used as hydrolytic solution.The fluorescence intensity of tryptophan was determined with excitation wavelength 225 nm and emission wavelength 350 nm.The linear range of calibration graph was 0~0.07 mg/L.The detection limit was 0.003 mg/L. The recovery rate of sample was 90%~(100.1%.)国家自然科学基金资助项目(40106007

Surface properties and changes in morphology of microplastics exposed in-situ to Chinese coastal wetlands

Coastal wetlands are key areas of accumulation of microplastics. However, until now only a few studies have focused on the surface properties and morphological changes in microplastics in the real coastal wetland environment. Here, two typical biogeographic coastal soils, the Yellow River Estuary salt marsh wetland in the temperate zone and the Beibu Bay mangrove wetland in the subtropical zone, were selected for study. Polystyrene foams and polyethylene films were used and exposed within two coastal wetlands sites through in situ soil burial (underground exposure) and surface placement (above-ground exposure). The samples were sampled after 6, 12, 18 and 24 months of exposure to reveal the characteristics of the surface properties and morphological changes in microplastics in typical wetlands from the southern and northern biogeographic coastal zones. The surface morphology, microstructures and attached materials were observed using scanning electron microscopy using an energy dispersive spectrometer. Surface properties of the microplastics, i.e. the surface roughness, specific surface area, pore size distribution, functional groups and hydrophobicity, were analyzed by using atomic force microscopy, a surface area analyzer, a mercury porosimeter, Fourier transform infrared spectrometry and a contact angle meter. The surface morphology of the polystyrene foams in the Beibu Bay mangrove wetland exhibited more pits and holes than those in the Yellow River Estuary salt marsh wetland. The polystyrene foams exposed aboveground in the Beibu Bay mangrove wetland showed embrittlement and exfoliation after 18 months, while those exposed underground did not show such features. The specific surface areas of the polystyrene foams and the polyethylene films in the Yellow River Estuary salt marsh wetland were higher than those in the Beibu Bay mangrove wetland. The pore distributions on the surfaces of the two microplastic types mainly comprised macropores and mesopores. However, the porosity of the polyethylene film in the Yellow River Estuary salt marsh wetland was slightly higher than in the Beibu Bay mangrove wetland. The porosities in both regions were higher than in the original control samples. In terms of carbonyl index, rates of change in the Yellow River Estuary salt marsh wetland were higher than those in the Beibu Bay mangrove wetland. The surface hydrophobicity of the polyethylene film in the two regions declined with increasing exposure time. The changes in surface morphology of the polystyrene foams were more rapid than those in the polyethylene films, but the degree of change in specific surface area of the polyethylene films was greater than in the case of the polystyrene foams. It can be concluded that the surface properties and changes in morphology of microplastics in the coastal soil environment are related to multiple factors including the types and conditions of the wetlands, types of microplastics, exposure mode and exposure time. However, the specific mechanisms of these surface changes require further study. In summary, this study provides a scientific basis for research on the chemical processes of the micro-interfaces on the microplastic surfaces and environmental behavior and risk assessment of microplastics in the Chinese coastal zone