现代汉语寄生语缺的最简分析

以移位的拷贝理论解释现代汉语寄生语缺的生成机制。在最简方案中,移位是拷贝、合并、形成语链和缩小语链的互动产出的结果,这统一解释了有些语迹为什么必须在语音成分中删除以满足线性化的句法要求、语迹为什么要循环移位和邻接原则、表层结构、反成分统制和A’移位等寄生语缺的主要性质。     

氩同位素体系定年标准物质研制

本项目的总体目标任务为研制新生代氩同位素体系定年分析标准物质1套（年龄〈50Ma）。工作起止年限为2008～2010年。     

Benthic foraminiferal δ~(13)C minimum events in the southeastern Okhotsk Sea over the last 180 ka

A total of six d13C minimum events,i.e.,VI,V,IV,III,II,and I,were observed via a stable carbon and oxygen isotope analysis of infaunal benthic foraminifera Uvigerina spp.in gravity core OS03-1 in the southeastern Okhotsk Sea over the last 180 ka.These events occurred at112–109,102–90,85–76,57–54,44–40,and 17–10 ka BP.The largest negative excursions reached 2.5%in event V and were greater than 1%in the other events.We proposed that all d13C minimum events were caused by the increase in sea surface water productivity,the weakened formation of Okhotsk Sea intermediate water,and the enhancement of the oxygen minimum zone.The negative excursions were unaffected by methane hydrate destabilization and subsequent methane release based on the results obtained by using archaeal lipid markers.     

氧气起源纷争再起

科学界一直相信，氧气在30亿年前便已出现在地球上，但是2000年时，美国马里兰大学的地质化学家James Farquhar发明了一种与硫同位素有关的技术，将氧气出现的年代定格在距今24亿年前。在一个化学反应中，相同元素的不同同位素的比例会发生变化。通常情况下，这些变化依赖于同位素的质量。然而Farquhar发现，在距今24亿年前，3种硫同位素之间的同位素变化却不依赖于同位素的质量。     

地下水流动和补给更新模式的水文地球化学示踪

地下水是地球上水的重要组成部分和构成全球水循环过程的重要环节,它分布广泛、水量和水位动态相对稳定、水质较好、便于开发利用和不易受污染,是农业灌溉、工矿企业和城市用水的重要水源。地下水中的化学组分(包括水化学离子和同位素等)蕴含了地质历史发展演化的一些证据,将其作为地下水流动和补给     

同位素内标法对水产品中硝基呋喃代谢物液相色谱-串联质谱法测定

建立了水产品中硝基呋喃类代谢物残留量的同位素内标定量液相色谱-串联质谱法测定。样品经稀盐酸水解,邻硝基苯甲醛衍生,乙酸乙酯提取净化后,用液相色谱-串联质谱法通过正离子扫描多反应监测模式检测,稳定同位素内标定量。本方法的线性范围为1.25～10μg/kg,4种硝基呋喃代谢物的线性相关系数均在0.993 2以上,4种化合物...     

Potential influence of water level changes on energy flows in a lake food web

Large seasonal water-level fluctuations may influence isotopic signatures of primary producers and the types and amounts of these potential food sources accessible to aquatic fauna of Poyang Lake,the largest freshwater lake in China.In this study,the isotopic signatures of primary producers and consumers were determined,stable carbon and nitrogen isotope analysis and mixing models were combined to investigate the influence of water levels on the diet and isotopic composition of Poyang Lake fish and inverteb...     

Molybdenum isotopic composition as a tracer for low-medium temperature hydrothermal ore-forming systems: A case study on the Dajiangping pyrite deposit,western Guangdong Province,China

Little is known about the range or controls on the molybdenum isotopic composition of low-medium temperature hydrothermal ore-forming systems. We present molybdenum isotope data from 12 hydrothermal syndepositional silicalite and carbonaceous slate samples from the Dajiangping pyrite deposit in western Guangdong Province, South China. The δ ^97/95 Mo values from Orebody III range from −0.02‰ to 0.29‰, with an average of 0.18‰. In contrast, the composition values from Orebody IV display a larger variation from −0.70‰ to 0.62‰. However, the five samples from the main ore bed all show strong negative values. This indicates that the significant variation in molybdenum isotopic composition supports different hydrothermal ore-forming metallogenesis and a metallogenic environment between the two orebodies. Orebody III is likely to have been deposited from submarine exhalative hydrothermal fluids under a relatively strong reducing environment and Orebody IV may have also been influenced by hydrothermal superimposition in a more oxidized disequilibrium condition. In addition, the δ ^97/95 Mo values of Orebody IV are clearly negative, together with the values increasing stratigraphically upward in the ore beds, suggesting that the metallogenic environment of Orebody IV is different from the open oceanic systems. There might be dynamic fractionation in this restricted environment. Therefore, the molybdenum isotope can be used as an effective tracer for the ore-forming fluid and metallogenic environment.     

“杜西结论”的推广

研究和推广"杜西结论",设α∈φn={(a1,a2,…,an)|ai∈N,i=1,2,…,n},定义杜西变换:D(α)=(|a1-a2|,|a2-a3|,…,|an-a1|),利用离散动力系统的分析方法,研究更一般的问题,得出结论:n(n=2k,(k=1,2,…))个自然数形成一个环形,再进行相邻两数大数减小数,则在有限步内n个数必都变为零,即对任意α∈φn,当n=2k,(k=1,2,…)时,存在m∈N,有Dm(α)=θ,并得出几个相关的结论.     

柴达木盆地西部新生代盐湖相烃源岩中高支链类异戊二烯烃(C25HBI)的检出及其地质地球化学意义

发育于盐湖相环境的柴达木盆地西部第三系渐新统下干柴沟组是该盆地西部地区的主力烃源岩层. 在该组上段沉积有机质中检出了硅藻的特征性生物标志化合物——含25 个碳原子的高支链类异戊二烯烃(C₂₅HBI), 该化合物的检出对于揭示区域沉积有机质发育的生物地球化学背景具有重要意义. 研究结果表明, 柴达木盆地西部地区下干柴沟组上段烃源岩中的C₂₅HBI 碳同位素值介于-18‰到-20‰之间, 为典型硅藻生源特征. 由于沉积环境中硅藻生长在大量消耗水体溶解CO₂ 的同时, 必须利用无机碳酸盐碳才能维持其快速繁殖, 硅藻勃发代表了水体环境富营养、高生产率特征, 因此富重碳同位素C₂₅HBI 在沉积有机质中的检出有可能成为该地区优质烃源层发育的标志之一. 同时, 由于硅藻发育环境水体溶解CO₂处于胁迫状态, 将导致沉积有机质总体以富集¹³C 为特征, 可能是造成该地区第三系沉积有机质碳同位素偏重的原因之一. 作为该套烃源岩沉积有机质的生源之一, 硅藻生源高碳数正构烷烃(>n-C₂₅)具有无碳优势分布的特点, 使得该地区高碳数正构烷烃的生源和成因复杂化,在烃源岩有机质评价时应引起重视.