理学 >>> 数学 信息科学与系统科学 物理学 化学 天文学 地球科学总论 大气科学 地球物理学 地理学 地质学 水文学 海洋科学 生物学 科学技术史
搜索结果: 1-15 共查到理学 Isotope ratios相关记录16条 . 查询时间(0.046 秒)
The carbon isotope ratios of organic carbon in settling particles collected in the highly-diatom-productive Bering Sea were determined. Wet decomposition was employed to oxidize relatively fresh orga...
We report the origin of significant fractionation of Pb isotope ratios in Ca-doped 0.08 mol L–1 HNO3 solutions. We applied Tl-spiked standard bracketing mass fractionation correction using solution-b...
We used d15N-nitrate (NO{ 3 ) and d18O-NO{ 3 to unravel the provenance and fate of NO{ 3 in a groundwater-fed estuary. A total of 13 monthly and two time series surveys were undertaken in the Werr...
We report high-resolution in situ Pb isotope analysis (207Pb/206Pb and 208Pb/206Pb ratios) by femtosecond laser ablation-multiple ion counter-inductively coupled plasma-mass spectrometry (fsLA-MIC-IC...
Characteristics of δ2 H and δ18O in precipitation samples collected at 16- to 17-d intervals at three stations at the northern end of Honshu Island, Japan, were investigated. Rokkasho and Ajigasawa ...
We propose an analytical protocol for the accurate in situ determination of 176Hf/177Hf isotope ratios in zircon crystals by a 193 nm ultraviolet excimer laser ablation (193ExLA) multiple-collector i...
Strontium-Neodymium isotopes and 28 elements for Kimberlites from China (Shandong and Liaoning) and from South Africa (Kimberley area) have been measured to estimate their chemical characteristics an...
To determine the accuracy and precision limits associated with carbon stable isotope ratio (δ13C) measurements of cellulose and lignin from plant samples, experiments were performed using differing e...
In view of the requirement of a well-characterized and easily available aquatic sediment reference material, a comprehensive analysis comprising of fifty major, minor and trace elements as well as Sr-...
Increasing numbers of studies have recently used stable isotopes of nitrogen (δ15N) and carbon (δ13C) to clarify the source of nutrients in lake water and sediments, the structure and energy flow of f...
Atmospheric chloromethane (CH3Cl) plays an important role in stratospheric ozone destruction, but many uncertainties still exist regarding strengths of both sources and sinks and the processes leading...
The δ17O and δ18O values of some international silicate reference materials such as NBS-28 quartz, NBS-30 biotite, UWG2 garnet, San Carlos olivine and some mineral separates of terrestrial origin were...
Hydrogen isotope ratios were measured on terrigenous alkanes (n-C25 to n-C31) extracted from recent lake surface sediments from the climatically and environmentally distinct basins Qiangyong Glacier L...
Stable isotopes are widely used to infer trophic relationships with little attention paid to temporal variability at the base of the food web. We examined changes in the carbon-stable isotope composit...
Spatial and temporal variations in stable carbon isotope ratios (i.e., δ13C) of primary producers are common but poorly understood features of isotopic characterizations of aquatic food webs. I invest...

中国研究生教育排行榜-

正在加载...

中国学术期刊排行榜-

正在加载...

世界大学科研机构排行榜-

正在加载...

中国大学排行榜-

正在加载...

人 物-

正在加载...

课 件-

正在加载...

视听资料-

正在加载...

研招资料 -

正在加载...

知识要闻-

正在加载...

国际动态-

正在加载...

会议中心-

正在加载...

学术指南-

正在加载...

学术站点-

正在加载...