Application of Radon and Radium Isotopes in Estimating Submarine Groundwater Discharge in Coastal Areas

海底地下水排泄(Sgd)是海岸带陆海相互作用的一个重要的过程,其重要意义体现在它对海岸带水循环和地球化学循环的影响,以及它对沿岸海域生态环境的影响。国际上自从20世纪90年代中期开始系统研究海底地下水排泄以来,已经研究和开发出一整套较为完善的理论和方法,但Sgd的研究在我国才刚刚起步,相关报道极少见且缺乏不同方法的对比研究。目前,评价Sgd常用的方法有:渗流仪法、数值模拟法和地球化学示踪法。其中以氡和镭为代表的地球化学示踪法成为最具影响力的评价方法。该文详细介绍用氡和镭同位素评价Sgd的理论和方法及其适用条件。Submarine groundwater discharge(SGD) is recognized as an important land-sea interaction in the coastal zone,for it is volumetrically and chemically significant to coastal water and chemical budgets,and it may have an influence on coastal ecological environment.Since the mid 90′s,a set of relatively complete theories and methods has been developed and established due to the systematic researches on SGD internationally.However the study on SGD has just begun in China,its relevant report is rarely available and short of comparison experiments of different methods.The current methods for SGD estimation mainly include: seepage meter measurement,numerical simulation,geochemical tracing method.Among those methods,geochemical tracing method has become one of the most powerful methods,and radium and radon as the representative of geochemical tracers has been extensively used.The methods and applicable conditions of SGD estimation using radon and radium isotopes are introduced in detail.近岸海域的海底地下水排泄及其海洋生态环境效应研究(编号40672166);多种方法研究胶州湾的海底地下水排泄(编号41072174

磁场特性与作用方式对hcfc141b气体水合物生成过程的影响

通过实验研究考察了静态磁场和旋转磁场下磁场特性与作用方式对低压制冷剂HCFC-141b气体水合物生成过程特性影响，重点研究在不同磁场条件下的气体水合物结晶形态、生成温度和引导时间三个重要因素．试验结果发现，适当的旋转磁场对提高水合物生成温度、降低过冷度、减少引导时间、提高生成速度有显著的作用，使结晶形态混杂致密；而适当的静态磁场则使水合物形态规整，有利于提高传热性能

Assessment of submarine groundwater discharge into the Wuyuan bay via continuous Radon-222 measurements

海底地下水排泄(Sgd)近年来成为陆-海相互作用的研究热点,地球化学示踪方法是其主要研究手段,尝试用天然示踪剂氡-222评价厦门五缘湾的Sgd。为了评价五缘湾Sgd的入海通量及其变化,对五缘湾海水中222rn和226rA活度、大气中222rn活度、风速、水温和水深进行了连续2 d的测量,对沉积物进行了培养实验用以获得其222rn扩散通量和孔隙水中222rn活度。基于海水中222rn通量的质量平衡,对实测的海水中222rn活度实施了母体支持、涨落潮影响、大气逃逸损失、沉积物扩散输入、混合损失的校正,保守估计Sgd输入的222rn通量在0~126.7 bQ/(M2·H)范围内变化,对海水中222rn的平均贡献达54%。以井水和孔隙水中222rn的加权平均值作为Sgd端元的代表,获得Sgd的输入速率为0~29.3 CM/d,平均输入速率9.3 CM/d。Sgd输入速率的动态变化基本围绕12 H的周期波动,是对本海域正规半日潮的具体响应。假设Sgd以平均速率在五缘湾海底输入,则五缘湾海底的Sgd输入量为1.86x105M3/d。以陆源地下淡水占Sgd输入量的10%考虑,五缘湾的陆源地下淡水输入量约为1.86x104 M3/d。In recent years,submarine groundwater discharge(SGD) has been recognized as an important process in land-ocean interactions in the coastal zone(LOICZ).The subject has thus become the focus of intensive research.Geochemical tracers can be effective tools for estimating SGD in LOICZ.The objective of this study is to estimate SGD in the Wuyuan Bay using Radon-222(222Rn) as naturally occurring tracer.The dynamic variation of SGD can thus be subsequently assessed.We continuously measure the seawater 222Rn and 226Ra activities,the near-sea surface air 222Rn,wind speed,sea water temperature and depth for two consecutive days.We also deploy an incubation device to measure the diffusive flux of 222Rn from sediments and the pore-water 222Rn activities.Based on the mass balance principle for the 222Rn flux,the measured seawater 222Rn are corrected for the decay product of parent 226Ra,the effects of tides,the losses to the atmosphere,the diffusive influxes from the sediments,and the mixing with offshore seawaters.The result shows a conservative estimate of 222Rn flux attributed to SGD is between 0 and 126.7 Bq/(m2 h),which can account for 54% 222Rn in seawater.Taking a SGD end-member as example,the calculated SGD input rates range from 0 to 29.3 cm/d with an average value of 9.3 cm/d.The end-member is made of the weighted average of groundwater and pore-water 222Rn activities.The fluctuation in the SGD input rate has a 12-h period,which matches well with the semi-diurnal tides in this region.The SGD input to the Wuyuan Bay could be as much as 1.86×105 m3/d if the estimation were made under the assumption that the average SGD input rate is applicable to the entire bay area.The input of terrestrially derived fresh groundwater in the Wuyuan Bay could be approximately 1.86×104 m3/d if the fresh groundwater were 10% of the total SGD input.国家自然科学基金资助项目(40672166;41072174)---

组学时代下植物—传粉者互作的研究

植物—传粉者互作对维持生态系统平衡和农业经济健康发展至关重要,它是自然界中进化与生态理论研究的理想模型.由于植物—传粉者互作机制涉及面广、尺度难以把握等因素,该领域的研究面临重重挑战.伴随着高通量技术革命性的发展,生命科学进入了解译海量多元数据的组学时代,这为植物—传粉者互作的研究提供了前所未有的机遇和平台.目前,组学在植物—传粉者互作研究中的应用主要集中在花性状遗传基础与生殖隔离、传粉者化学感受、传粉者学习记忆、植物—传粉者化学交流、植物—传粉者系统发育及多样性等方面.这些领域的研究为全面揭示植物—传粉者生命活动中相关功能基因、系统发生、进化轨迹以及生物多样性保护奠定了基础.未来,我们期望通过组学技术从更深层次上了解植物—传粉者互作关系,从而解答一些长期存在的进化生物学和生态学基本问题

高温含尘烟气深度净化和高品位余热回收一体化技术与装备

针对工业高温含尘烟气净化困难以及高品位余热难以回收的技术瓶颈,采用自制的陶瓷膜过滤管,通过耦合换热元件,首次研发出陶瓷膜高温除尘与换热一体化装置。通过结合亚松弛因子和数值模拟优化了一体化装置结构,使得装置内流场更均匀。通过液化气燃烧产生高温烟气并在烟道中可控地加入粉尘模拟高温含尘烟气,实验结果表明,该装置可对1000℃以上含尘烟气进行除尘与换热,除尘效率99.98%以上,净化后含尘浓度小于10 mg/m^3(标准工况);换热效率70%以上。研发的高温除尘与换热一体化装置在实现烟气深度净化的同时高效回收了高品位余热,为能源的高效利用提供了一种新的途径

Estimating groundwater discharge into Minjiang River estuary based on stable isotopes deuterium and oxygen-18

通过分析闽江河口区降水、地表水和地下水的氢氧稳定同位素特征,揭示降水的环境同位素效应和地下水的形成演化规律,定量评价河口区多种水体的混合过程及地下水输入量。夏季的降水氢氧同位素组成相对贫化,呈现出降雨量效应。在δ18O与δd关系图上,闽江北岸基岩裂隙水、平原及丘陵区浅层地下水均落在福州降水线上,而南岸平原及丘陵区浅层地下水大部分落在福州降水线右下方,其拟合线与降水线交点与5~9月农灌期降水氢氧同位素加权值接近,表明北岸地下水主要来自降水补给,而南岸地下水同时接受灌溉水和降水补给,并在入渗过程中经历了不同程度的蒸发作用。闽江河口段除接受两岸地下水补给外,局部河段还接受断裂带裂隙水补给。将线性端元混合模型、数字高程模型和地下水文分析法结合起来定量评价地下水的输入和各水体的混合过程,结果显示,在河口段淡水区,地下水混合比率上限为8.8%,其中包括0.4%的断裂带裂隙水;在河口段淡咸水混合区,淡水(河水、地下水)和海水的混合比为53∶47,其中地下水的保守混合比率为1.7%;枯水期闽江河口段地下水保守输入量为87.0 M3/S,是闽江径流量的12.8%。Through analyzing the characteristics of deuterium and oxygen-18 composition in precipitation,surface water and groundwater,this paper will reveal the isotopic effects of precipitation,the origin and evolution of groundwater,and estimate the mixing processes between various water bodies and groundwater discharge into the Minjiang River estuary.The hydrogen and oxygen isotopic compositions of precipitation are more depleted in heavy isotopes during summer,showing the so-called amount effect.The δ18O versus δD plots for two types of water samples are on the Fuzhou local meteoric water line(LMWL).The two water types are the fissure groundwater and the shallow groundwater respectively collected from a mountainous area in the north bank of the Minjing River estuary and a piedmont plain and hilly land.By contrast,the shallow groundwater samples collected from a piedmont plain and hilly land in the south bank of the Minjiang River estuary mostly fall in the lower right side of LMWL.The intersection points of the two fitted lines on LMWL are so close to the weighted average of isotopic composition of meteoric water during the local agricultural irrigation period from May to September.The result shows that the groundwater in the north bank is mainly recharged from meteoric water,while the groundwater in the south bank is simultaneously recharged from both irrigation water and meteoric water accompanied by a different degree of evaporation during the infiltration process.In addition to the groundwater from both sides of Minjiang River estuary,fracture water from the fracture zone also locally recharge into the estuary.The linear end member mixing model,the digital elevation model and the underground hydrologic analysis are combined to quantitatively study the groundwater contribution to the estuary and the mixing processes among various water sources.The modeling results show that the maximum mixing ratio of groundwater is up to 8.8% in the freshwater zone of the estuary including 0.4% of the fracture water.In the saltwater zone of the estuary,the ratio of freshwater(river water and groundwater) to seawater is 53∶47,which includes approximately 1.7% of groundwater.The conservative estimate of groundwater discharge into the Minjiang River estuary is 87.0 m3/s which accounts for 12.8% of the Minjiang River runoff during the dry season.福建省重点基金资助项目(2009I0025);国家自然科学基金资助项目(41072174)---

高温含尘烟气深度净化和高品位余热回收一体化技术与装备

针对工业高温含尘烟气净化困难以及高品位余热难以回收的技术瓶颈,采用自制的陶瓷膜过滤管,通过耦合换热元件,首次研发出陶瓷膜高温除尘与换热一体化装置。通过结合亚松弛因子和数值模拟优化了一体化装置结构,使得装置内流场更均匀。通过液化气燃烧产生高温烟气并在烟道中可控地加入粉尘模拟高温含尘烟气,实验结果表明,该装置可对1000℃以上含尘烟气进行除尘与换热,除尘效率99.98%以上,净化后含尘浓度小于10 mg/m^3(标准工况);换热效率70%以上。研发的高温除尘与换热一体化装置在实现烟气深度净化的同时高效回收了高品位余热,为能源的高效利用提供了一种新的途径