Languaging as proposed by Swain(2006) is an important theoretical construct in second language(L2) learning. The construct was evolved from Swain’s own notion of comprehensible output with the paradigm shift from the...Languaging as proposed by Swain(2006) is an important theoretical construct in second language(L2) learning. The construct was evolved from Swain’s own notion of comprehensible output with the paradigm shift from the psycho-cognitive to the sociocognitive perspective on second language acquisition. Raised within the input-output model of L2 learning and as a supplement to comprehensible input.展开更多
The microstructures and mechanical properties of C-Mn-Cr-Nb and C-Mn-Si-Nb ultra-high strength dual-phase steels were studied by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and tens...The microstructures and mechanical properties of C-Mn-Cr-Nb and C-Mn-Si-Nb ultra-high strength dual-phase steels were studied by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and tensile test. The results show that Si can promote the transformation of austenite （γ） to ferrite （α）, enlarge the （α＋γ） region, and increase the aging stability of martensite by inhibiting carbide precipitation. Adding Cr leads to the formation of retained austenite and martensite/austenite （M/A） constituents, as well as the decomposi- tion of martensite during the overaging stage. Both of the steels show higher initial strain-hardening rates and two-stage strain-hardening characteristics. The C-Mn-Si-Nb steel shows the higher strain-hardening rate than the C-Mn-Cr-Nb steel in the first stage; however, there is no significant difference in the second stage. Although the tensile strength and elongation of the two steels both exceed 1000 MPa and 15%, respectively, the comprehensive mechanical properties of the C-Mn-Si-Nb steel are superior.展开更多
基金supported by China’s National Social Science Project Funding(No.2021BYY048)the Ministry of Education Project of the Centre for Linguistics and Applied Linguistics and the Bilingual Cognition and Development Lab,Guangdong University of Foreign Studies(No.290-X5219075).
文摘Languaging as proposed by Swain(2006) is an important theoretical construct in second language(L2) learning. The construct was evolved from Swain’s own notion of comprehensible output with the paradigm shift from the psycho-cognitive to the sociocognitive perspective on second language acquisition. Raised within the input-output model of L2 learning and as a supplement to comprehensible input.
基金financially supported by the National Natural Science Foundation of China(No.50904006)the Fundamental Research Funds for the Central Universities of China(No.FRT-TP-10-001A)
文摘The microstructures and mechanical properties of C-Mn-Cr-Nb and C-Mn-Si-Nb ultra-high strength dual-phase steels were studied by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and tensile test. The results show that Si can promote the transformation of austenite （γ） to ferrite （α）, enlarge the （α＋γ） region, and increase the aging stability of martensite by inhibiting carbide precipitation. Adding Cr leads to the formation of retained austenite and martensite/austenite （M/A） constituents, as well as the decomposi- tion of martensite during the overaging stage. Both of the steels show higher initial strain-hardening rates and two-stage strain-hardening characteristics. The C-Mn-Si-Nb steel shows the higher strain-hardening rate than the C-Mn-Cr-Nb steel in the first stage; however, there is no significant difference in the second stage. Although the tensile strength and elongation of the two steels both exceed 1000 MPa and 15%, respectively, the comprehensive mechanical properties of the C-Mn-Si-Nb steel are superior.
