We present first-principles calculations of the formation energy of different native defects and their complexes in wurtzite InN using density-functional theory and the pseudopotential plane-wave method. Our calculati...We present first-principles calculations of the formation energy of different native defects and their complexes in wurtzite InN using density-functional theory and the pseudopotential plane-wave method. Our calculations are aimed in the three cases： N/In = 1, N/In 〉 1 （N-rich）, and N/In 〈 1 （In-rich）. Our results indicate that the antisite defect has the lowest formation energy under N/In = 1. The formation energy of nitrogen interstitial （nitrogen vacancy） defect is significantly low under the N-rich （In-rich） condition. Thus the antisite defect is an important defect if N/In = 1, and the nitrogen interstitial （nitrogen vacancy） defect is a vital defect under the N-rich （In-rich） condition. The atomic site relaxation around the nitrogen interstitial and vacancy is investigated. Our calculations show that the nitrogen vacancy cannot be observed although it is one of the most important defects in InN. Our results are confirmed by experiments.展开更多
Within the framework of Conceptual Transfer Hypothesis （Jarvis, 2007; 2011）, this paper investigates Chinese-speaking L2-English learners＇ computation of the uniqueness of noun phrases （NPs）, which further leads ...Within the framework of Conceptual Transfer Hypothesis （Jarvis, 2007; 2011）, this paper investigates Chinese-speaking L2-English learners＇ computation of the uniqueness of noun phrases （NPs）, which further leads to their selection of English articles in marking the target NPs. An acceptability judgment task and a written interview task were used to collect data of L2 learners＇ interpretation of English articles. The results reveal that the L2 learners differ from native speakers in their computation of uniqueness of target NPs and in their L2-English article choices, and this difference can be attributed to their conceptual knowledge formed in the acquisition of the mother tongue and to their processing of such knowledge. Pedagogically, this study provides an explanation of L2-English article substitution errors from the perspective of conceptual transfer.展开更多
基金Supported by the National Basic Research Program of China under Grant No. 2006CB921607the National Natural Science Foundation of China under Grant Nos. 60711120203, 60890193+1 种基金the Natural Science Foundation of Beijing City under Grant No. 1092007the Science and Technology Research Foundation for Colleges and Universities of Inner Mongolia Autonomous Region under Grant No. NJ09026
文摘We present first-principles calculations of the formation energy of different native defects and their complexes in wurtzite InN using density-functional theory and the pseudopotential plane-wave method. Our calculations are aimed in the three cases： N/In = 1, N/In 〉 1 （N-rich）, and N/In 〈 1 （In-rich）. Our results indicate that the antisite defect has the lowest formation energy under N/In = 1. The formation energy of nitrogen interstitial （nitrogen vacancy） defect is significantly low under the N-rich （In-rich） condition. Thus the antisite defect is an important defect if N/In = 1, and the nitrogen interstitial （nitrogen vacancy） defect is a vital defect under the N-rich （In-rich） condition. The atomic site relaxation around the nitrogen interstitial and vacancy is investigated. Our calculations show that the nitrogen vacancy cannot be observed although it is one of the most important defects in InN. Our results are confirmed by experiments.
基金I am grateful to Prof. Chuming Wang （GDUFS, China） and Dr. Tania Ionin （UIUC, USA） for their guidance in writing this paper. Thanks to two anonymous reviewers for very helpful comments and suggestions thanks also to the support from Social Science Foundation of Guangdong Province, China （Grant No. GD11YWW04）. All remaining errors are my own.
文摘Within the framework of Conceptual Transfer Hypothesis （Jarvis, 2007; 2011）, this paper investigates Chinese-speaking L2-English learners＇ computation of the uniqueness of noun phrases （NPs）, which further leads to their selection of English articles in marking the target NPs. An acceptability judgment task and a written interview task were used to collect data of L2 learners＇ interpretation of English articles. The results reveal that the L2 learners differ from native speakers in their computation of uniqueness of target NPs and in their L2-English article choices, and this difference can be attributed to their conceptual knowledge formed in the acquisition of the mother tongue and to their processing of such knowledge. Pedagogically, this study provides an explanation of L2-English article substitution errors from the perspective of conceptual transfer.
