What is the difference between L1 acquisition and L2 acquisition？ How does knowing this help us as teachers of English to speakers of other languages？ Could we use this knowledge of the difference in class？ The art...What is the difference between L1 acquisition and L2 acquisition？ How does knowing this help us as teachers of English to speakers of other languages？ Could we use this knowledge of the difference in class？ The article tries to explore the difference and answer these questions.展开更多
This paper focuses on variables affecting L1 transfer in L2 acquisition, which, according to the author, are categorized into three groups： learner-related variables, language-based variables and socio-linguistic var...This paper focuses on variables affecting L1 transfer in L2 acquisition, which, according to the author, are categorized into three groups： learner-related variables, language-based variables and socio-linguistic variables, and each of them is clarified in more details.展开更多
This paper deals with the influence of L1 （first Language） mental lexicon on L2 （second Language） mental lexicon with Chinese subjects. It proves two possibilities： the response types in L1 and L2 of a single ind...This paper deals with the influence of L1 （first Language） mental lexicon on L2 （second Language） mental lexicon with Chinese subjects. It proves two possibilities： the response types in L1 and L2 of a single individual may be similar, and the dominant language （mostly L1） and the L2 may interfere with each other＇s vocabulary depth and breadth. The result is of great significance for Chinese learners of English.展开更多
Weak L1 signal acquisition in a high dynamic environment primarily faces a challenge： the integration peak is neg- atively influenced by the possible bit sign reversal every 20 ms and the frequency error. The block a...Weak L1 signal acquisition in a high dynamic environment primarily faces a challenge： the integration peak is neg- atively influenced by the possible bit sign reversal every 20 ms and the frequency error. The block accumulating semi-coherent integration of correlations （BASIC） is a state-of-the-art method, but calculating the inter-block conjugate products restricts BASIC in a low signal-to-noise ratio （SNR） acquisition. We propose a block zero-padding method based on a discrete chirp-Fourier transform （DCFT） for parameter estimations in weak signal and high dynamic environments. Compared with the conventional receiver architecture that uses closed-loop acquisition and tracking, it is more suitable for open-loop acquisition. The proposed method combines DCFT and block zero-padding. In this way, the post-correlation signal is coherently post-integrated with the bit sequence stripped off, and the high dynamic parameters are precisely estimated using the threshold set based on a false alarm probability. In addition, the detection performance of the proposed method is analyzed. Simulation results show that compared with the BASIC method, the proposed method can precisely detect the high dynamic parameters in lower SNR when the length of the received signal is fixed.展开更多
文摘What is the difference between L1 acquisition and L2 acquisition？ How does knowing this help us as teachers of English to speakers of other languages？ Could we use this knowledge of the difference in class？ The article tries to explore the difference and answer these questions.
文摘This paper focuses on variables affecting L1 transfer in L2 acquisition, which, according to the author, are categorized into three groups： learner-related variables, language-based variables and socio-linguistic variables, and each of them is clarified in more details.
文摘This paper deals with the influence of L1 （first Language） mental lexicon on L2 （second Language） mental lexicon with Chinese subjects. It proves two possibilities： the response types in L1 and L2 of a single individual may be similar, and the dominant language （mostly L1） and the L2 may interfere with each other＇s vocabulary depth and breadth. The result is of great significance for Chinese learners of English.
基金supported by the National Natural Science Foundation of China(Nos.61172138 and 61401340)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2013JQ8040)+4 种基金the Research Fund for the Doctoral Program of Higher Education of China(No.20130203120004)the Open Research Fund of the Academy of Satellite Application(No.2014_CXJJ-DH_12)the Xi’an Science and Technology Plan(No.CXY1350(4))the Fundamental Research Funds for the Central Universities(Nos.201413B,201412B,and JB141303)the Open Fund of Key Laboratory of Precision Navigation and Timing Technology,National Time Service Center,CAS(Nos.2014PNTT01,2014PNTT07,and 2014PNTT08)
文摘Weak L1 signal acquisition in a high dynamic environment primarily faces a challenge： the integration peak is neg- atively influenced by the possible bit sign reversal every 20 ms and the frequency error. The block accumulating semi-coherent integration of correlations （BASIC） is a state-of-the-art method, but calculating the inter-block conjugate products restricts BASIC in a low signal-to-noise ratio （SNR） acquisition. We propose a block zero-padding method based on a discrete chirp-Fourier transform （DCFT） for parameter estimations in weak signal and high dynamic environments. Compared with the conventional receiver architecture that uses closed-loop acquisition and tracking, it is more suitable for open-loop acquisition. The proposed method combines DCFT and block zero-padding. In this way, the post-correlation signal is coherently post-integrated with the bit sequence stripped off, and the high dynamic parameters are precisely estimated using the threshold set based on a false alarm probability. In addition, the detection performance of the proposed method is analyzed. Simulation results show that compared with the BASIC method, the proposed method can precisely detect the high dynamic parameters in lower SNR when the length of the received signal is fixed.
