U.S.-France Planning Visit: Nanostructured Iron Oxides: Nature's Signatures of Environmental Change

OISE-0834047美法规划访问：纳米结构氧化铁：自然？S环境变化签名该提案将资助一组美国研究人员对法国进行为期六天的访问，与法国同事共同研究天然氧化铁纳米颗粒，这种纳米颗粒可以作为气候和人类引发的环境变化的敏感记录器。美国团队包括Lee Penn博士、初级研究助理Subir Banerjee博士和明尼苏达大学双子城分校的两名研究生，以及加州大学的两名同事。法国队由巴黎大学教授Philippe Sainctavit领导。美国的参与者是纳米颗粒化学、合成、磁性和结晶学方面的专家。法国的参与者是X射线、磁性、圆二色和中子散射方面的专家。这些后一种技术可以为氧化铁纳米颗粒最外层的独特磁自旋取向提供强有力的测试。美国团队正在开发一个中心假说，该假说涉及氧化铁纳米颗粒的核壳磁性和化学结构的概念，并阐明该结构及其对纳米铁颗粒的化学行为(例如，纳米颗粒表面的氧化还原化学)的影响，对于开发准确描述环境变化带来的磁性和化学变化至关重要。因此，合作应该导致第一个完整的磁性和化学描述，从而能够根据过去降雨和温度的重大变化对土壤和沉积物中当前的磁性观测进行严格解释。需要这样的定量解释作为测试美国和其他地方正在开发的区域气候变化数值模型的基准。

OISE-0834047 U.S.-France Planning Visit: Nanostructured Iron Oxides: Nature?s Signature of Environmental ChangeThis proposal will fund a six day visit to France for a team of U.S. researchers to develop a joint research proposal with French colleagues dealing with natural iron oxide nanoparticles that act as sensitive recorders of climate- and human-induced environmental changes. The U.S. team includes Dr. Lee Penn, Dr. Subir Banerjee, a junior research associate and two graduate students for the University of Minnesota-Twin Cities, as well as two colleagues from the University of California. The French team is led by Professor Philippe Sainctavit of the University of Paris. The U.S. participants are experts in nanoparticle chemistry, synthesis, magnetism, and crystallography. The French participants are experts in X-ray magnetic circular dichroism and neutron scattering. These latter techniques can provide powerful tests for unique magnetic spin orientations in the outermost 'shells' of the iron oxide nanoparticles. The U.S. team is developing a central hypothesis dealing with the idea of a core-shell magnetic and chemical structure of the iron oxide nanoparticles, and elucidating that structure and its impact on the chemical behavior (e.g., redox chemistry at nanoparticle surfaces) of iron nanoparticles is critical to the development of precise descriptions of magnetic and chemical changes brought about by environmental changes. Thus, the collaboration should lead to the first complete magnetic and chemical description enabling rigorous interpretations of current magnetic observations in soils and sediments in terms of past major changes in rainfall and temperature. Such quantitative interpretations are needed to act as benchmarks for testing numerical regional climate change models now being developed in the United States and elsewhere.