基于纳米间隔电极对的DNA分子结电输运的研究进展

脱氧核糖核酸分子是一类重要的生物分子,在生物医学领域之外,该类分子还因为其所具有的独特的双螺旋结构以及长程输运能力,在分子电子学领域也引起了研究者的极大兴趣.本文综述了近年来基于纳米间隔电极对构筑分子结这一研究范式,在构筑脱氧核糖核酸分子结以及研究后者的电输运性质等方面的研究进展.依据研究者所采用的不同纳米间隔电极对构筑技术,主要围绕裂结法和切割法两大类研究方法所展开.前者主要包括扫描隧道显微镜裂结法、导电原子力显微镜法、机械可控裂结法,后者则主要包括碳纳米管切割法、石墨烯切割法、硅纳米线切割法.在梳理不同实验方法的发展脉络、比较不同实验方法的各自特点的基础上,对一些具有代表性的关于脱氧核糖核酸分子结的研究工作进行了重点介绍,探讨了脱氧核糖核酸分子结所具有的与常规小分子体系所不同的特殊电学性质,同时对该领域的未来发展进行了展望.中南大学湘雅三医院“新湘雅人才工程”(No.20150203)国家重点研发计划(No.2017YFA0204902)国家自然科学基金(No.21722305)资助~

Application of vertically integrated sampling approach to studyingnew production via 234Th -238U disequilibria

对基于梯形积分原理的集成采样法的可行性在理论上进行了阐述，并在厦门湾和南海北部的５个站位分别采集不同深度的水样和由这些水样按一定比例混合而成的集成水样进行了现场研究，结果表明两种采样方法经不可逆稳态清除模型得出的溶解态２３４Ｔｈ的清除通量、颗粒态２３４Ｔｈ的输出通量及溶解态、颗粒态２３４Ｔｈ的停留时间基本一致，证实了垂直集成采样法的可行性与可靠性．这种新的采样方案为今后充分发挥２３４Ｔｈ法的优势，在更大空间尺度上进行新生产力的研究提供了可靠的保证． 【英文摘要】 --The spatial and temporal distributions of new production vary largely in different sea areas. To understand the level ofnew production in the study sea area better, an estimate of new production must be obtained in large spatial and temporal scales.The disequilibrium of 234Th -- 238U is an effective method for studying new production. Two sampling projects, i. e., vertically integrated sampling approach(based on trapezoidal integration) and discrete layer sampling approach, are compared in the Xiamen Baya...国家自然科学基金!49676296;;“九五”国家科技攻关计划资助!97-926-04-0

Spatial and temporal distributions of some metal elements in suspended particulate matter from Station“Shangyu” in Xiamen Bay

本文测定了在厦门湾上屿附近海域定点站（“上屿”站）６个航次所采集悬浮颗粒物中Ｆｅ、Ｍｎ、Ａｌ、Ｔｉ、Ｂａ和Ｃａ ６种金属元素的含量，并结合其他相关要素，探讨了该海域悬浮颗粒物的化学组成及其生物地球化学特性。对悬浮颗粒物中Ｆｅ、Ｍｎ、Ａｌ、Ｔｉ、Ｂａ和 Ｃａ等元素的垂直分布与时间变异研究发现，它们多数与悬浮颗粒物关系密切，沉积物再悬浮作用是控制水体尤其是底层水悬浮颗粒物时空变化的主要因素。与厦门西港和九龙江口相比，上屿海域属于厦门湾海区，中受陆源输入影响较小的海域。 【英文摘要】 The contents of Fe, Mn, Al, Ti, Ba and Ca in suspended particulate matter were deter mined at Station“Shangyu” in Xiamen Bay during six cruises in 1996. The spatial and tem poral variations of these elements in suspended particulate matter were studied along with other related chemical and biological parameters. Most of them are correlated with TSM. The results suggest that TSM is mainly influenced by sediment resuspension, especially in bottom waters. As compared to Western Xiamen Harbour and Jiulongjiang .国家自然科学基金!（49676296号

Vertical distribution and temporal variation of --(234)Th in water column at Station "Shangyu"in Xiamen Bay

1996年 9~10月在厦门湾上屿附近海域定点站连续6个航次测定了水柱中溶解态（dTH）、颗粒态--(234)TH（PTH）和溶解态--238u，获得了--234TH的时空分布图象。研究海域水柱中dTH、PTH和总--234TH（TTH）的放射性比度分别在0.80~3.95山/M--3、1，93~5.65bQ/ M--3和 3.47~9. 18bQ/M--3之间，整个水柱中 dTH、PTH和TTH均与--(238)u呈不平衡，其特征是--(234)TH亏损，且亏损程度明显大于大洋水体。颗粒态--(234)TH和总悬浮颗粒物（TSM）在水体中的分布及其随时间的变化趋势相当一致，非生物过程可能对近岸海域水体中--(234)TH的分布起着非常重要的作用。The vertical distribution and temporal variation of --(234)Th activities in water column were studied at Station "Shangyu" in Xiamen Bay in six weeks.The specific activities of dissolved.particulate and total --234Th are 0.80--3.95, 1.93--5.65, and 3.47--9.18 Bq/m--3, respectively.The vertical distribution of DTh activity is higher in surface and lower in bottom waters.and profile of PTh activity on the contrary.The both profiles ate closely related to the profile of TSM.PTh activities are higher than DTh in the coastal waters studied.Vertical distribution of total.dissolved, and particulate --(234) Th relative to --(238) U showed more deficiency throughout the water column in Xiamen Bay than in open ocean.Temporal variations of particulate and dissolved --(234)Th correlated well with TSM and the distribution of --(234)Th may be largely influenced by non-biological processes.国家自然科学基金!（49676296

Study of dissolved uranium isotopes in some sea areas of China

本文测定了南沙海域、南海东北部海域、厦门湾塔角附近海域与九龙江口水体中溶解态238U含量及其同位素组成。南沙、南海东北部海域溶解态238U比度及234U／238U）A.R.呈均匀分布状态，进一步证实开阔大洋水中铀同位素分布的均匀性。厦门湾塔角附近海域238U含量较南海水来得高，且其变化与盐度的变化不相协调，表明该海域也许存在238U的附加来源。四个研究海区溶解态U／S值的大小顺序为：厦门湾塔角附近海域＞九龙江口＞南沙海域≈南海东北部海域。 【英文摘要】 The dissolved 238U concentration and 234U/238U activity ratios in the Nansha waters, the northeastern South China Sea,Xiamen Bay and Jiulongjiang Estuary have been extensivelystudied. The distribution of uranium concentrations and 234U/238U activity ratios in the Nan-sha waters and the N-E South China Sea reflects the uniform characteristic of uranium in theopen ocean. The concentration of 238U in Xiamen Bay is higher than those in the South ChinaSea,in addition,their variation does not coordinate with sali...国家自然科学基金!4937627

厦门湾水体中~(234)Th的垂直分布及其时间变异特征

１９９６年 ９～１０月在厦门湾上屿附近海域定点站连续６个航次测定了水柱中溶解态（ＤＴｈ）、颗粒态~(２３４)Ｔｈ（ＰＴｈ）和溶解态~２３８Ｕ，获得了~２３４Ｔｈ的时空分布图象。研究海域水柱中ＤＴｈ、ＰＴｈ和总~２３４Ｔｈ（ＴＴｈ）的放射性比度分别在０．８０～３．９５山／ｍ~３、１，９３～５．６５Ｂｑ／ ｍ~３和 ３．４７～９． １８Ｂｑ／ｍ~３之间，整个水柱中 ＤＴｈ、ＰＴｈ和ＴＴｈ均与~(２３８)Ｕ呈不平衡，其特征是~(２３４)Ｔｈ亏损，且亏损程度明显大于大洋水体。颗粒态~(２３４)Ｔｈ和总悬浮颗粒物（ＴＳＭ）在水体中的分布及其随时间的变化趋势相当一致，非生物过程可能对近岸海域水体中~(２３４)Ｔｈ的分布起着非常重要的作用。 【英文摘要】 The vertical distribution and temporal variation of ~(234)Th activities in water column were studied at Station "Shangyu" in Xiamen Bay in six weeks. The specific activities of dissolved. particulate and total ~234Th are 0. 80~3. 95, 1. 93~5. 65, and 3. 47~9. 18 Bq/m~3, respectively. The vertical distribution of DTh activity is higher in surface and lower in bottom waters. and profile of PTh activity on the contrary. The both profiles ate closely related to the profile of TSM. PTh activities are higher than...国家自然科学基金!（49676296

Time-series study of primary production and related parameters at Station "Shangyu" in Xiamen Bay

１９９６年９～１０月在厦门湾上屿附近海域定点站连续６个航次测定了初级生产力和其它水文、化学和生物学要素，在较短的时间尺度内研究了初级生产力及相关要素的时间变异特征。初级生产力、叶绿素 ａ、颗粒有机碳（ＰＯＣ）、总悬浮颗粒物（ＴＳＭ）和营养盐等要素随时间的变化表明了沿岸水域海洋过程发生的短暂性和沿岸水体中颗粒物质来源的复杂性。 【英文摘要】 The primary production(PP) and related hydrological,chemical and biological parame- ter were measured at Station "Shangyu" in Xiamen Bay during six cruises. The temporal and spatial variations of PP and related parameters show the transient marine process and the complexity of the source of particle material in the coastal waters.国家自然科学基金!4967629

Geochemical behavior of dissolved and particulate uranium isotopes in Jiulongjiang estuary

对九龙江河口区枯、丰水期水体中溶解态、颗粒态铀同位素地球化学行为的研究表明，溶解态铀与盐度存在良好的正相关关系，证实枯、丰水期该河口区水体中的铀均是保守行为。在低盐度区域（Ｓ＜１０），~２３８Ｕ主要以颗粒态形式存在，颗粒态~２３８Ｕ所占份额随盐度增加而降低。~（２３８）Ｕ之条件分配系数介于 １． ２ × １０~３～１． ５ ×１０~５ｄｍ~３／ｋｇ之间，它与盐度呈负相关关系，但与悬浮颗粒物浓度无相关关系存在。枯水期悬浮颗粒物上~２３４Ｕ／~２３８Ｕ_Ａ．Ｒ．与盐度的负相关关系为河口区悬浮颗粒物中~２３４Ｕ的优先沥取理论提供了有力的证据。 【英文摘要】 The geochemical behavior of dissolved and particulate uranium isotopes during spring and dry seasons in Jiulongjiang estuary have been studied. Conservation behavior during estuary mixing in both seasons is shown by linear uranium-salinity plots.~238U in low salinity region(S<10) is largely incorporated into filterable particles. The percentages of particulate to total~238U in seawaters decrease with salinity. The conditional distribution coefficiences for ~238U ranged from 1. 2 × 10~3~1.5 × 10~5dm~3/kg, wh...国家自然科学基金!49676296