An electrochemical and microstructural characterization of steel-mortar admixed with corrosion inhibitors

The present research brings new insights on the role of admixed corrosion inhibitors in the processes of cement hydration and rebar corrosion.The admixing of NaCl and the corrosion inhibitors in fresh mortar was found to alter the morphology and microstructure of the hardened mortar at the steel-mortar interfacial region.The admixing of the inhibitors increased the risk of carbonation of cement hydrates at the steel-mortar interfacial region,but partially displaced chloride ions. Chloride and the admixed in...     

Extreme deuterium enrichment in stratospheric hydrogen and the global atmospheric budget of H2

Molecular hydrogen (H2) is the second most abundant trace gas in the atmosphere after methane (CH4). In the troposphere, the D/H ratio of H2 is enriched by 120 per thousand relative to the world's oceans. This cannot be explained by the sources of H2 for which the D/H ratio has been measured to date (for example, fossil fuels and biomass burning). But the isotopic composition of H2 from its single largest source--the photochemical oxidation of methane--has yet to be determined. Here we show that the D/H ratio of stratospheric H2 develops enrichments greater than 440 per thousand, the most extreme D/H enrichment observed in a terrestrial material. We estimate the D/H ratio of H2 produced from CH4 in the stratosphere, where production is isolated from the influences of non-photochemical sources and sinks, showing that the chain of reactions producing H2 from CH4 concentrates D in the product H2. This enrichment, which we estimate is similar on a global average in the troposphere, contributes substantially to the D/H ratio of tropospheric H2.     

纳米技术与发展中国家

作者将“nano*”与世界银行确定的每个经济类主题词组合检索，结果发现发展中国家普遍在从事
纳米技术研发。进一步研究表明，尽管发展中国家纳米技术的研发能力随着合作和信息利用的加强而提高，
但是这些国家已经偏离了纳米技术的“社会开发”这一通常被认为是最适于发展中国家的研究宗旨。另外，
对卫生保健相关专利的分析证实，各国实力严重不平衡，存在所谓的“纳米鸿沟”现象。在发展中国家中，
中国拥有的专利权所占份额很高，因此“纳米鸿沟”不仅存在于发展中国家和发达国家之间，在发展中国
家也同样存在。发展中国家的研发水平较低，纳米技术有可能走向以往导致全球技术大分裂的技术老路。     

A novel order reduction method for nonlinear dynamical system under external periodic excitations

The concept of approximate inertial manifold (AIM) is extended to develop a kind of nonlinear order reduction technique for non-autonomous nonlinear systems in second-order form in this paper. Using the modal transformation, a large nonlinear dynamical system is split into a ‘master’ subsystem, a ‘slave’ subsystem, and a ‘negligible’ subsystem. Accordingly, a novel order reduction method (Method I) is developed to construct a low order subsystem by neglecting the ‘negligible’ subsystem and slaving the ‘slav...     

Positional identification of TNFSF4, encoding OX40 ligand, as a gene that influences atherosclerosis susceptibility

Ath1 is a quantitative trait locus on mouse chromosome 1 that renders C57BL/6 mice susceptible and C3H/He mice resistant to diet-induced atherosclerosis. The quantitative trait locus region encompasses 11 known genes, including Tnfsf4 (also called Ox40l or Cd134l), which encodes OX40 ligand. Here we report that mice with targeted mutations of Tnfsf4 had significantly (P 相似文献