171 research outputs found

    Estimating Submarine Groundwater Discharge into the Jiaozhou Bay Using ~(226)Ra

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    海底地下水排泄(SGD)是全球水循环的一个组成部分,其输送的溶解物质不仅参与海洋的生物地球化学循环,而且影响近岸海域的生态环境。为了评估胶州湾海底地下水排泄状况,通过建立胶州湾内海水中226Ra的质量平衡模型来计算海底地下水排泄通量。胶州湾海水中226Ra的源主要有河流的输入、沉积物扩散输入和地下水的输入,海水系统在稳定状态下,这几种源应该与湾内海水和湾外海水的混合损失达到平衡。除了将地下水输入作为未知项外,对其他源和汇逐个进行量化,计算得知:2011年9—10月胶州湾的海底地下水排泄通量为7.85×10~6m~3·d~(-1);2012年4—5月胶州湾的海底地下水排泄通量为4.72×106m~3·d~(-1)。在此基础上,对地下水输入胶州湾的营养盐进行了评价。Submarine groundwater discharge( SGD) is a part of global water cycle,which delivers a large amount of solutes to the biogeochemical cycle and affects the coastal ecological environment. The ~(226)Ra mass balance model was established to estimate the submarine groundwater discharge to the Jiaozhou Bay. The ~(226)Ra sources include river transport,sediment diffusion and SGD,these sources should be in balance with the mixing loss of the bay water and open seawater when the seawater system is in the stable state. Except for the SGD was unknown item,other sources and sinks were quantified one by one. Calculated results showed that the SGD fluxes during September to October in 2011 was 7. 85 × 106m~3·d~(-1),April to May in 2012 was 4. 72 × 106m~3·d~(- 1). Based on the SGD fluxes,the SGD derived nutrient fluxes were estimated.国家自然科学基金项目(41072174)~

    Optimization of β-Cyclodextrin Inclusion Technology of Volatile Oil from Pueraria Compound by Orthogonal Design

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    目的优选葛根复方挥发油的包合工艺,提高制剂的稳定性。方法采用饱和水溶液法制备包合物,以挥发油中藁本内酯、桂皮醛、甲基丁香酚包合率及包合物得率为综合评价指标,采用正交试验法考察挥发油与β-环糊精的比例、包合时间、包合温度对包合工艺的影响,优化得到葛根复方中挥发油的最优包合工艺。结果葛根复方中挥发油的最佳包合工艺条件为挥发油与β-环糊精比例为1∶8,包合温度为30℃,包合时间为1h,验证试验中,藁本内酯、桂皮醛及甲基丁香酚的包合率为别为86.58%±0.009%,73.34%±0.001%,68.89%±0.020%,包合物得率为67.98%±0.047%。结论所确定的包合工艺挥发油的包合率高、工艺稳定可行。Objective To obtain the optimized technology of volatile oil from Pueraria Compound with β-Cyclodextrin( β-CD). Methods The inclusion compound was prepared by saturated peroxide solution method. In order to optimize inclusion technology,orthogonal design was performed,with the content of multi-target ingredient,such as ligustilide,cinnamic aldehyde,methyleugenol and the yield of inclusion as comprehensive evaluation indexes. Three factor was performed,the ratio of volatile oil( m L) to β-CD( g),the inclusion temperature and the inclusion time. Results The optimum conditions for inclusion process were as follow: the ratio of volatile oil( m L) to β-CD( g) was 1: 8,the inclusion temperature was 30℃ and the inclusion time was 1h. With the optimum inclusion condition,the content of ligustilide,cinnamic aldehyde and methyleugenol and the yield of inclusion were 86. 58% ± 0. 009%,73. 34% ± 0. 001%,68. 89% ± 0. 020%,and 67. 98% ± 0. 047%,respectively.Conclusion The optimum inclusion condition was stable and reproducible with a high inclusion yield.国家自然科学基金(No.81270901);上海市教委基金(No.15cxy21

    The Estimation of Submarine Inputs of Groundwater to a Coastal Bay Using Radium Isotopes

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    福建省漳州市隆教湾海水中镭同位素的研究,目的是评价海底地下水排泄量。在2007年6月的航次中,垂直于岸线的9km剖面上布置15个站位,每个站位用潜水泵采集表层海水样60L于塑料桶中。水样运回实验室后,立即用装有锰纤维的PVC管以虹吸的方式富集水样中的镭同位素,水通过PVC管的流速小于300ml/min。224Ra活度用连续射气法测定,测完224Ra后密封7d以上,然后用直接射气法测定226Ra活度。224Ra和226Ra活度都呈现自岸向海逐渐降低的规律,表明扩散控制镭同位素的分布,由224Ra获得68.83km2d-1的扩散系数,同时226Ra形成-0.963dpm100l-1km-1的活度梯度。用扩散系数和活度梯度建立的226Ra的离岸通量为6.62×1011dpmkm-2d-1,这个通量一定是得到SGD输入的镭支持,从而获得隆教湾的海底地下水排泄量是3.03×109m3km-2d-1。该排泄量包括陆源地下淡水排泄量和再循环海水排泄量,绝大部分可能是再循环海水,有待进一步研究。This paper reports the results of initial research on radium isotopes of surface ocean waters in the Longjiao Bay on the western flank of Taiwan Strait. The main objective of this research is to assess the submarine groundwater discharge (SGD). In order to assess the spatial distribution of 224Ra and 226Ra, the authors collected 15 surface ocean water samples (ca. -1 m in depth) during the low tide. The collection was performed within a period of 2 hours in the direction from onshore to 9 km offshore by using 60 L polypropylene buckets. In the laboratory, the water samples were immediately treated through gravity-fed PVC column (4.5 cm in diameter, 50 cm in length), filled with manganese oxide-impregnated acrylic fiber at a flow rate of ~300 ml/min to retain radium. After that, the activities of 224Ra absorbed on the Mn-fiber were measured through the continuous emanation method. Finally, the Mn-fiber was sealed for more than 7 days, and the activities of 226Ra absorbed on the Mn-fiber were measured through the direct emanation method. 226Ra distribution yields an activity gradient of -0.963 dpm100 l-1km-1. The short-lived 224Ra distribution in this region yields an eddy diffusion coefficient of 68.83 km2d-1. The interpretation is that the eddy diffusion is the primary controlling agent for the shore perpendicular distribution of the long-lived 226Ra. In order to estimate the seepage rate of groundwater in the study area, the authors applied the approach developed by Moore. The short-lived radium isotopes, 224Ra, were used to establish the eddy diffusion coefficient for the near-shore study area. The product of the eddy diffusion coefficient and the offshore 226Ra activity gradient established the 226Ra flux of 6.62×1011dpmkm-2d-1. It is expected that this flux must be balanced by Ra input from the submarine groundwater discharge (SGD). On the basis of the flux of SGD within the shore, 226Ra budget was calculated as 3.03×109 m3km-2d-1. This magnitude of SGD includes terrestrially-derived fresh SGD and recirculated seawater SGD, However, further researches should be required to determine the terrestrially-derived fresh SGD on the one hand, and recirculated seawater SGD on the other hand.国家自然科学基金项目(编号:40672166)资

    Determination of 1-Hydroxyethylidene-1,1-Diphosphonic Acid in Recycle-Cooling Water by Ion Chromatography

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    建立了循环冷却水中羟基-1,1-亚乙基二磷酸(HEDP)的离子色谱检测方法。色谱柱为IonPac AS14A阴离子交换柱,流动相为80mmol/L NaOH水溶液,流速1.0mL/min,抑制型电导检测器检测。方法的线性范围为0.25-25mg/L,平均回收率为102%,检出限为0.1mg/L;对0.25mg/L和0.5mg/L的HEDP标准溶液分别进行13次平行测定,相对标准偏差(RSD)分别为4.7%和3.5%。该方法具有简单、快速、灵敏、抗干扰等优点,用于循环冷却水中HEDP的检测,结果令人满意。1-Hydroxyethylidene-1,1-diphosphonic acid(HEDP) is usually used as a scale and corrosion inhibitor in recycle-cooling water for steel industry.The quick and accurate analysis of HEDP concentration in water is of importance to control the inhibitor adding program.However,the common method for HEDP analysis,which determines the total phosphate in water samples,may suffer the serious problem of incorrectly including degraded HEDP as the active HEDP reagent.In this study,the method of the determination of HEDP in recycle-cooling water by ion chromatography was investigated.The chromatographic parameters,including elution and detection,were optimized.The separation was achieved on an IonPac AS14A column with NaOH solution of 80 mmol/L as the eluent at a flow rate of 1.0 mL/min,and the detection was performed by a suppressed conductivity detection mode with the injection volume of 25 μL.The method showed good linearity within the range of 0.25 and 25 mg/L with an average recovery of 102%.The detection limit of the method reached as low as 0.1 mg/L.The relative standard deviations for 0.25 and 0.5 mg/L HEDP standard solutions were 4.7% and 3.5%(n=13),respectively.The method has been applied for the determination of HEDP in recycle-cooling water samples with the advantages of being simple,fast,sensitive,and interference free.上海市科委科研计划项目课题(04-b-02

    Advance in Pyrolysis and Gasification of Combustible Solid Waste and Engineering Simulation Study

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    简要介绍了目前国内城市生活垃圾的产生现状及其主要的处理方法。概述了典型可燃固体废弃物的热解气化实验进展和基于AspenPlus平台模拟的研究现状以及热解气化技术的应用情况。分析总结了热解温度和加热速率对热解产物分布及其产量的影响,以及空气燃料比和气化温度对气化过程的影响。基于AspenPlus平台的热解气化模型能够很好地模拟实际热解气化过程,具有较好的可靠性和实用性。指出可燃固废热解气化实验今后的研究重点及AspenPlus平台模拟研究的着重考虑因素

    Temporal and spatial variation of nutrients in the rivers around Jiaozhou Bay and its fluxes into the sea

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    本文选取胶州湾周边5条主要入海河流作为研究对象,于2011秋季和2012年春季,测定了河流中无机营养盐的浓度水平,调查了各河流营养盐的主要来源,分析了营养盐的时空变化及成因,并计算了营养盐的入海通量.结果表明,各流域nO-3-n、SIO2-3-SI、nH+4-n、nO-2-n浓度主要表现为秋季较高,PO3-4-P浓度春季较高.白沙河、洋河流域营养盐主要来源为面源污染;墨水河、李村河流域营养盐主要来源于工业废水和生活污水;大沽河流域营养盐主要来源于农田径流和生活污水.除nH+4-n入海通量为墨水河最高外,其余各项营养盐入海通量均为大沽河最高.dIn、PO3-4-P、SIO2-3-SI入海通量分别为373.74x103MOl·d-1、7.08x103MOl·d-1、73.16x103MOl·d-1,n∶P∶SI数量比约为53∶1∶10.River runoff is the most important discharge pathway from mainland to sea,which is one of the reasons that the eutrophication and red tide occur frequently in parts of Jiaozhou Bay.The nutrient investigations about five relatively big rivers around Jiaozhou Bay were conducted in autumn of 2011 and spring of 2012,respectively.We measured the nutrient concentrations in river water, investigated the main resources of nutrients,analyzed the temporal and spatial variations of nutrients and its causes, and calculated the nutrient fluxes to Jiaozhou Bay.Results show that the concentrations of NO-3-N, SiO2-3-Si, NH+ 4-N and NO-2-N are higher in autumn while the concentration of PO3-4-P is higher in spring.Non-point source pollution is the main source of nutrients in Baisha River and Yang River.Industrial wastewater,urban sewage and household wastes are the main sources of nutrient in Moshui River,and the nutrients originate mainly from farmland runoff and sewage in Dagu river.Except for NH+ 4-N flux which is much higher in Moshui River,all other nutrient fluxes to the sea are comparatively higher in Dagu River.The calculated fluxes for DIN,PO3-4-P and SiO2-3-Si are 373.74 × 103mol·d- 1,7.08 ×103mol·d- 1and 73.16 × 103mol·d- 1, respectively,and the ratio of N,P and Si within the fluxes is 53 ∶ 1 ∶ 10.国家自然科学基金项目资助(41072174)资

    Characteristics of Radium Desorption from Sediments in the Salt Water Environment

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    海底沉积物向上覆水体扩散的镭是海洋水体中镭同位素的重要来源之一。为了研究沉积物中镭同位素的解吸和扩散特点,进行了不同盐度和不同粒度条件下224rA和226rA解吸的模拟实验,并通过多个时间段的沉积物培养实验获取224rA和226rA的扩散通量。实验结果表明:随着水体盐度增大,沉积物中224rA、226rA的解吸量随之增加,在盐度为25时,解吸量基本达到最大值;在同一咸水环境条件下,4个粒级(2000~1000μM、1000~500μM、500~250μM、250~125μM)的沉积物的224rA、226rA解吸量比较接近,粒级>2000μM的224rA、226rA解吸量略高于上述4个粒级,而粒级<125μM的224rA、226rA解吸量远大于上述5个粒级;胶州湾沉积物中224rA和226rA的平均扩散通量分别为0.85 bQ·M–2·d–1和0.022 bQ·M–2·d–1。Radium diffusion from sediments to overlying water is one of the important sources of radium isotopes in ocean water.A series of laboratory desorption/diffusion experiments were conducted to help elucidate the characteristics of sediments on 224 Ra and 226 Ra desorption and diffusion,which included 1) 224 Ra and 226 Ra desorption from sediments in water of different salinities,2) 224 Ra and 226 Ra desorption from sediments of different grain sizes in water of the same salinity,3) 224 Ra and 226 Ra diffusive fluxes by observing Ra enrichment with time in the overlying water of incubated sediments.The experimental results show that there is an increase in the amount of 224 Ra and 226 Ra with the increase of salinity from 5 to 30,and Ra desorption is strongest at the salinity of 25.Under the same salt water condition,224 Ra and 226 Ra desorption activities of the four grain sizes(2000~1000 μm,1000~500 μm,500~250 μm and 250~125 μm) of sediments are very close to each other.When the grain sizes of sediments are larger than 2000μm,the 224 Ra and 226 Ra desorption activities are slightly higher than those of the sediments of the above-mentioned four grain sizes.When the grain sizes of sediments are less than 125 μm,the 224 Ra and 226 Ra desorption activities are much larger than those of the above-mentioned five grain sizes.The average diffusive fluxes of 224 Ra and 226 Ra of sediments from Jiaozhou Bay are 0.85 Bq·m-2·d-1 and 0.022 Bq·m-2·d-1,respectively.国家自然科学基金项目(编号:41072174)资

    The Evaluation of Submarine Groundwater Discharge in Jiaozhou Bay Based on ~(222)Rn Mass Balance

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    海底地下水排泄(Sgd)作为全球水循环的一个组成部分,近年来成为陆海相互作用的研究热点。地球化学示踪法是研究海底地下水排泄的主要手段。本文以环境同位素222rn作为示踪剂,通过构建222rn质量平衡模型来评价胶州湾的海底地下水排泄,并进一步估算地下水输入的营养盐。222rn质量平衡模型的源项考虑了河流的输入、沉积物的扩散、母体226rA的支持,汇项考虑了222rn的自身衰变、222rn散逸到大气的损失以及与湾外海水的混合损失,源汇项的差值则作为地下水输入的222rn通量。结果表明,2011年9—10月胶州湾海底地下水排泄通量为24.2 l?M–2?d–1,2012年4—5月胶州湾海底地下水排泄通量为7.8 l?M–2?d–1。丰水季节地下水输入胶州湾的营养盐低于河流输入的,但是枯水季节地下水输入的营养盐接近河流输入的,特别是输入的活性磷酸盐和硅酸盐很接近。Submarine groundwater discharge(SGD), an important part of global water cycle, has recently been a research focus in the field of land-ocean interaction along the coastal zone.Geochemical tracing is a major tool to study submarine groundwater discharge.Taking natural occurring isotope 222 Rn as a tracer, the authors built 222 Rn mass balance model to estimate groundwater discharge to Jiaozhou Bay, and also evaluated the nutrient fluxes transported via groundwater.River input, dispersion of sediments, and support from parent 226 Ra are considered to be the sources of 222 Rn mass balance model, whereas radioactive decay, escape from sea-water interface to air and loss in mixing with the low activity water from open ocean are considered to be the sink of the model.Thus, the imbalance of budget from the model is attributed to submarine groundwater discharge.Calculations show that submarine groundwater discharge flux to Jiaozhou Bay was 24.2 L·m–2·d–1 from September to October in 2011, and 7.8 L·m–2·d–1 from April to May in 2014, respectively.The results of the study also indicate that the nutrient fluxes derived from groundwater during the wet season are lower than those transported by the local rivers, whereas the nutrient fluxes derived from groundwater during the dry season are close to those transported by the local rivers and, what is more, soluble reactive phosphate and silicate fluxes from both groundwater and river are very close to each other.国家自然科学基金项目(编号:41072174)资

    基于选择集成学习的表面增强拉曼光谱检波算法(英文)

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    文章提出了一种表面增强拉曼光谱的检波算法.该算法基于选择性学习和3种经典检波算法,构建了一个组合波峰检测器.结果表明,与传统算法相比,针对波峰提取,作者的算法有更好的正确率和检出...National Natural Science Foundation of China(Grant Nos.61472333,61772441,61472335);; Project of marine economic innovation and development in Xiamen(No.16PFW034SF02);; Natural Science Foundation of the Higher Education Institutions of Fujian Province(No...

    MnO/Nitrogen-doped graphene composite cathode for high performance lithium oxygen batteries

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    本文采用水热法制备了MnO/氮掺杂石墨烯复合材料. 作为非水锂空气电池的正极催化剂, 该复合材料表现出了优异的电化学性能以及循环稳定性.; 在充放电电流密度为0.05 mA cm~(-2)时, 其能量效率高达84.6%, 远高于目前文献所报道的非贵金属催化剂的能量效率,; 也超过了基于贵金属的催化剂. 其氧还原反应(ORR)和氧析出反应(OER)的过电势分别仅为0.11和0.41 V.; 扫描电子显微镜(SEM)和透射电子显微镜(TEM)结果表明, 所制备的MnO纳米颗粒能够均匀地分散在氮掺杂石墨烯的表面.; 密度泛函理论(DFT)计算揭示, MnO(100)面是主要的催化活性面, 其理论ORR和OER的过电势分别仅为0.21与0.24 V,; 充放电电势差为0.45 V, 与实验结果0.52 V相当.MnO/nitrogen-doped graphene (MnO/NG) composite cathode was fabricated by; a facile one-pot method as cathode catalyst for non-aqueous lithium; oxygen batteries. It exhibited superior electrochemical performance with; higher round-trip efficiency and better cyclic stability. It showed a; high round-trip efficiency of 84.6% at the current density of 0.05 mA; cm~(-2) with the discharge and charge overpotentials of 0.11 and 0.41 V,; respectively. Through scanning electron microscopy, transmission; electron microscopy and X-ray photoelectron spectroscopy, it was; confirmed that MnO nanoparticles were homogeneously dispersed on NG; surface. The density functional theory calculations demonstrated that; the superior electrochemical performance of MnO/NG might be attribute to; the exposure of stoichiometric MnO (100) surface, with the ORR and OER; overpotential only to be 0.21 and 0.24 V, respectively. The; discharging-charging voltage gap is 0.45 V, in good agreement with the; experimental value of 0.52 V.国家重点基础研究发展计划; 国家自然科学基金; 国家基础科学人才培养基
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