An interesting phenomenon of cooling-rate induced brittleness in Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass （BMG） was reported. It was found that the as-cast BMG specimens exhibited a brittle-ductile transition w...An interesting phenomenon of cooling-rate induced brittleness in Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass （BMG） was reported. It was found that the as-cast BMG specimens exhibited a brittle-ductile transition when the larger specimens were machined into smaller specimens through removing the cast-softening surface layer by layer. After compression tests, the as-machined small specimens, owing to the absence of the cast-softening surface, displayed highly dense and intersecting shear bands, and extensive plastic deformation. This is in contrast to the catastrophic failure and low deformability in the as-cast large specimens. More free volume was detected in the smaller as-fractured specimens, by differential scanning calorimetry, which may be attributed to the occurrence of strain softening and increased plasticity. Compared with the relatively smooth fracture surface in the smaller specimens, the larger specimens showed more diverse features on the fracture surface due to their graded structures.展开更多
The Fe78Si9B13 glassy ribbons were compressed at room temperature with different pressures. The thermal and corrosion behaviors were investigated using various experimental techniques. The X-ray diffraction （XRD） an...The Fe78Si9B13 glassy ribbons were compressed at room temperature with different pressures. The thermal and corrosion behaviors were investigated using various experimental techniques. The X-ray diffraction （XRD） and dilatometer （DIL） results show that the Fe78Si9B13 ribbons are in full amorphous state after pressing and the amount of free volume increases monotonically with increasing pressure. The corrosion resistance of the glassy alloys in various solutions decreases after compression at 10 MPa, but increases after compression at 20 MPa. The non-monotonic change of corrosion resistance is consistent with the result of electrical resistivity, which can be explained by the combining action of free volume that is introduced by the compression and the segregation of Si atoms in the samples.展开更多
In the present work the electronic density of states of liquid,viz.,Zintli alloys,have been studied only at the composition of their maximum resistivity to have an elementary idea about the behaviors of the alloys wit...In the present work the electronic density of states of liquid,viz.,Zintli alloys,have been studied only at the composition of their maximum resistivity to have an elementary idea about the behaviors of the alloys with respect to nearly free electron behavior.The study reveals that the anomalous electronic behavior of liquid Li-Pb,Na-Pb,Li-Sn,and Na-Sn can be attributed to the preferential ordering of unlike atoms.展开更多
Press has been found to have an impact on the outcome of electoral political campaigns. Press can distort the electorate＇s perception of an objective reality to fulfill the political orientation of its editorial line...Press has been found to have an impact on the outcome of electoral political campaigns. Press can distort the electorate＇s perception of an objective reality to fulfill the political orientation of its editorial line. This can be achieved in propaganda and in the rhetoric of excess. Within the framework of Critical Discourse Analysis （CDA）, this paper has conducted a thematic content analysis to study the rhetoric of excess in the construction of political identity and relations in 100 articles pertaining to two different ideologically oriented Tunisian newspapers, namely Le Maghreb and El Dhamir. The study covered the period from December 26, 2011 to December 26, 2012. Results have shown a low level of impartiality violating Gricean maxims of quality and quantity. This tendency could culminate in violence and undermine the public＇s confidence in the media. Proactive measures of media management are recommended.展开更多
基金Project(2012M511401)supported by China Postdoctoral Science FoundationProject(12JJ5018)supported by Hunan Provincial Natural Science Foundation of China+1 种基金Project(2012RS4006)supported by Hunan Provincial Science and Technology Plan of ChinaProject(CSUZC2012028)supported by the Open-End Fund for the Valuable and Precision Instruments of Central South University,China
文摘An interesting phenomenon of cooling-rate induced brittleness in Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass （BMG） was reported. It was found that the as-cast BMG specimens exhibited a brittle-ductile transition when the larger specimens were machined into smaller specimens through removing the cast-softening surface layer by layer. After compression tests, the as-machined small specimens, owing to the absence of the cast-softening surface, displayed highly dense and intersecting shear bands, and extensive plastic deformation. This is in contrast to the catastrophic failure and low deformability in the as-cast large specimens. More free volume was detected in the smaller as-fractured specimens, by differential scanning calorimetry, which may be attributed to the occurrence of strain softening and increased plasticity. Compared with the relatively smooth fracture surface in the smaller specimens, the larger specimens showed more diverse features on the fracture surface due to their graded structures.
基金Projects (50871061, 51171091) supported by the National Natural Science Foundation of ChinaProjects (2008BS04020, BS2010CL027) supported by the Shandong Excellent Youth Award Foundation, ChinaProject (JQ201012) supported by the Excellent Youth Project of Shandong Natural Science Foundation, China
文摘The Fe78Si9B13 glassy ribbons were compressed at room temperature with different pressures. The thermal and corrosion behaviors were investigated using various experimental techniques. The X-ray diffraction （XRD） and dilatometer （DIL） results show that the Fe78Si9B13 ribbons are in full amorphous state after pressing and the amount of free volume increases monotonically with increasing pressure. The corrosion resistance of the glassy alloys in various solutions decreases after compression at 10 MPa, but increases after compression at 20 MPa. The non-monotonic change of corrosion resistance is consistent with the result of electrical resistivity, which can be explained by the combining action of free volume that is introduced by the compression and the segregation of Si atoms in the samples.
文摘In the present work the electronic density of states of liquid,viz.,Zintli alloys,have been studied only at the composition of their maximum resistivity to have an elementary idea about the behaviors of the alloys with respect to nearly free electron behavior.The study reveals that the anomalous electronic behavior of liquid Li-Pb,Na-Pb,Li-Sn,and Na-Sn can be attributed to the preferential ordering of unlike atoms.
文摘Press has been found to have an impact on the outcome of electoral political campaigns. Press can distort the electorate＇s perception of an objective reality to fulfill the political orientation of its editorial line. This can be achieved in propaganda and in the rhetoric of excess. Within the framework of Critical Discourse Analysis （CDA）, this paper has conducted a thematic content analysis to study the rhetoric of excess in the construction of political identity and relations in 100 articles pertaining to two different ideologically oriented Tunisian newspapers, namely Le Maghreb and El Dhamir. The study covered the period from December 26, 2011 to December 26, 2012. Results have shown a low level of impartiality violating Gricean maxims of quality and quantity. This tendency could culminate in violence and undermine the public＇s confidence in the media. Proactive measures of media management are recommended.
