The Solvated Metal Atom Impregnation (SMAI) technique was employed to prepare macroporous resin immobilized Pd--Cu bimetallic cluster catalysts. The X--ray diffraction (XRD) and transmission electron micrograph (TEM) ...The Solvated Metal Atom Impregnation (SMAI) technique was employed to prepare macroporous resin immobilized Pd--Cu bimetallic cluster catalysts. The X--ray diffraction (XRD) and transmission electron micrograph (TEM) showed that Pd--Cu alloy was formed and the particle sizes of Pd--Cu clusters were very small, with average diameters <3nm. X--ray photoelectron spectroscopy indicated that both Pd and Cu were in zero--valent state. The catalytic activities of the macroporous resin immobilized Pd--Cu catalysts in hydrogenation of 4--methyl--3--penten--2--one were much greater than that of the carbon supported Pd--Cu catalysts.展开更多
This paper focuses on a direct quantitative identification of crisis periods in selected emerging stock markets from four continent-based regions of Europe, Latin America, East Asia, and Middle East and North Africa ...This paper focuses on a direct quantitative identification of crisis periods in selected emerging stock markets from four continent-based regions of Europe, Latin America, East Asia, and Middle East and North Africa （MENA）, in the context of an influence of the 2007 U.S. subprime financial crisis. The 17 emerging stock markets and, for comparison, the U.S. stock market are investigated. A statistical method of dividing market states into bullish and bearish markets, based on monthly logarithmic returns of major stock market indexes, is employed. The analyzed sample period begins in January 2003 and ends in December 2013. As there is no unanimity in the literature about the crisis periods in the continent-based regions, a formal statistical identification of crises is worthwhile to conduct. Furthermore, the effect of increasing cross-market correlations in the crisis compared to the pre-crisis period in the context of contagion is examining. To address this issue, both standard contemporaneous cross-correlations and volatility-adjusted cross-correlations are applied. The results are consistent with the literature and confn＇m that tests for contagion based on cross-market correlations are problematic due to the bias introduced by changing volatility in market returns. As contagion can be confused with globalization, the globalization tests in the group of international investigated markets are employed. The results generally do not confirm a global world market integration effect, i.e. there is no reason to reject the research hypothesis of no globalization during the 2007-2009 financial crisis.展开更多
The thermal stability,glass-forming ability(GFA) and mechanical properties of Zr60Al15Ni25xTMx(TM = Cu,Fe and Co,x = 0-10) bulk metallic glasses(BMGs) were systematically investigated.Additional 5-10 at.% Cu greatly e...The thermal stability,glass-forming ability(GFA) and mechanical properties of Zr60Al15Ni25xTMx(TM = Cu,Fe and Co,x = 0-10) bulk metallic glasses(BMGs) were systematically investigated.Additional 5-10 at.% Cu greatly enhances the thermal stability and GFA of the base alloy.Zr60Al15Ni15Cu10 BMG exhibits the largest supercooled liquid region of 104 K and critical diameter of 18 mm.However,addition of 5-10 at.% Fe or Co decrease the thermal stability and GFA.In addition,the plasticity of the BMG can be improved by adding of Cu,while the strength is decreased slightly.Zr60Al15Ni20Cu5 BMG has the largest plastic strain of 5.5% with a yield stress of 1755 MPa and Young's modulus of 83 GPa.Addition of Co brings an increase of strength but a lower of plasticity,and additional Fe reduces the strength and plasticity simultaneously.展开更多
文摘The Solvated Metal Atom Impregnation (SMAI) technique was employed to prepare macroporous resin immobilized Pd--Cu bimetallic cluster catalysts. The X--ray diffraction (XRD) and transmission electron micrograph (TEM) showed that Pd--Cu alloy was formed and the particle sizes of Pd--Cu clusters were very small, with average diameters <3nm. X--ray photoelectron spectroscopy indicated that both Pd and Cu were in zero--valent state. The catalytic activities of the macroporous resin immobilized Pd--Cu catalysts in hydrogenation of 4--methyl--3--penten--2--one were much greater than that of the carbon supported Pd--Cu catalysts.
文摘This paper focuses on a direct quantitative identification of crisis periods in selected emerging stock markets from four continent-based regions of Europe, Latin America, East Asia, and Middle East and North Africa （MENA）, in the context of an influence of the 2007 U.S. subprime financial crisis. The 17 emerging stock markets and, for comparison, the U.S. stock market are investigated. A statistical method of dividing market states into bullish and bearish markets, based on monthly logarithmic returns of major stock market indexes, is employed. The analyzed sample period begins in January 2003 and ends in December 2013. As there is no unanimity in the literature about the crisis periods in the continent-based regions, a formal statistical identification of crises is worthwhile to conduct. Furthermore, the effect of increasing cross-market correlations in the crisis compared to the pre-crisis period in the context of contagion is examining. To address this issue, both standard contemporaneous cross-correlations and volatility-adjusted cross-correlations are applied. The results are consistent with the literature and confn＇m that tests for contagion based on cross-market correlations are problematic due to the bias introduced by changing volatility in market returns. As contagion can be confused with globalization, the globalization tests in the group of international investigated markets are employed. The results generally do not confirm a global world market integration effect, i.e. there is no reason to reject the research hypothesis of no globalization during the 2007-2009 financial crisis.
基金supported by the Fundamental Research Funds for the Central Universities of China(Grant Nos.DUT11RC(3)70 and DUT11RC(3)29)the National Natural Science Foundation of China (Grant No.51171034)the China Postdoctoral Science Foundation (Grant No.2012M510802)
文摘The thermal stability,glass-forming ability(GFA) and mechanical properties of Zr60Al15Ni25xTMx(TM = Cu,Fe and Co,x = 0-10) bulk metallic glasses(BMGs) were systematically investigated.Additional 5-10 at.% Cu greatly enhances the thermal stability and GFA of the base alloy.Zr60Al15Ni15Cu10 BMG exhibits the largest supercooled liquid region of 104 K and critical diameter of 18 mm.However,addition of 5-10 at.% Fe or Co decrease the thermal stability and GFA.In addition,the plasticity of the BMG can be improved by adding of Cu,while the strength is decreased slightly.Zr60Al15Ni20Cu5 BMG has the largest plastic strain of 5.5% with a yield stress of 1755 MPa and Young's modulus of 83 GPa.Addition of Co brings an increase of strength but a lower of plasticity,and additional Fe reduces the strength and plasticity simultaneously.
