第二语言课堂教学环境中的可提供性

在美国心理学家James Gibson提出可提供性(Affordance)之后,可提供性理论被不断发展,并应用于多个领域,如社会学、认知心理学、生态学、设计学,甚至第二语言教学。可提供性从人与环境互动关系的角度启发二语教师尽可能地创造和优化教学环境中的学习机会,同时在教学中不断培养和提高学生对第二语言学习环境中可提供性的感知能力及其主观能动性,努力实现学生参与互动学习。学生对语言要素和知识的感知能力提高,就越容易获得环境中的可提供性,学习机会越大化就越可能促进其知识的内化并达到学习效果。本文首先对可提供性理论的发展进行了梳理和回顾,进而区分可提供性理论所定义的第二语言学习"环境"与传统的学习环境,并阐述在该环境下的可提供性的特点和表现。最后,探讨可提供性理论在第二语言课堂教学环境下的可行性及其应用,旨在为第二语言教学特别是汉语作为第二语言教学开启一个新的视角,重新审视固有的教学观念和现有教学中存在的一些相关问题。

可提供性理论视阈下基于社交网络的汉语学习研究

随着学科之间的不断交流与融合,使得新的理论得以产生和发展。生态学的兴起推动了生态心理学、生态语言学和生态教育学等学科的发展,而基于生态学和生态心理学则产生了可提供性理论。这一理论并不是一种完全成熟的理论,只是一种概念性的理解。然而,这一概念的出现对第二语言教学产生了重要影响,其与多种人工智能设备的结合在第二语言教学中扮演着重要角色。此外,随着社交网络的蓬勃发展,为学习者的汉语学习提供了新的契机。基于可提供性理论的视角,探索了社交网络在对外汉语教学中的作用,研究发现:基于社交网络的对外汉语教学无法提升学习者整体的汉语能力,但对于提升学习者的汉语词汇、阅读和写作能力具有显著作用。

联合国“4A框架”下新疆少数民族青少年教育状况解读——以南疆四所中学调研结果为样本

新疆南疆少数民族青少年教育对实现个人发展、改善民生、维护民族团结、边疆稳定和社会长治久安具有极其重要的意义。基于此,课题组在对南疆第一手调研数据进行统计分析的基础上,结合联合国经济社会和文化权利委员会提出的教育"4A框架"予以对照性考察,进而分析展示南疆少数民族青少年的教育状况;并以"4A框架"为参照提出提升南疆少数民族青少年教育水平的路径。

基于生态语言学视角的汉语习得理论思考

生态语言学作为生态学与语言学相结合而成的新兴学科,其宗旨在于利用生态学的理论来阐释人类语言,认为人类语言同样具有生态系统的特征,诸如开放性,动态性,整体性,平衡性,交互性等。此外,生态语言学认为第二语言习得具有两大特点:突现性与可提供性。因此本文基于生态语言学所强调的观点以及第二语言习得应该具备的特征,审视汉语习得领域的相关理论假说的合理性,并提出相关的建议,以期为对外汉语教学的良性发展提供一些指导。

Affordance Derivation Facilitates the Semantic Access in Comprehending Chinese Puns

The study employed ERP technique to explore whether the affordance derivation can facilitate semantic access in comprehending Chinese puns. ERPs were measured while participants read the pun sentences containing dual meanings and made a judgement about the following probes and statements. The results showed that highly related probes in pun sentences elicited a smaller N400 and a larger LPC than moderately related probes in pun sentences. As for the comparison of sentence types, both highly and moderately related probes in pun sentences produce a smaller N400 and a larger LPC than those in control sentences. These results indicate that in the early stage of pun comprehension, semantic access to the literal meaning is easier through affordance derivation because of meaning dominance and frequency. In the late stage of integration, however,the intended meaning of puns can be facilitated and accessed through its privilege of affordance derivation activated by pun words in a pun context because of the priming context and its underlying intention. The study has discovered empirically that it is the affordance derivation,which connects the context and the dual meanings indicated by the pun words, that contributes to the different time courses and dynamic underlying neurocognitive mechanisms in comprehending puns in Chinese.

Certificateless Public Key Encryption with Keyword Search

Public Key Encryption with Keyword Search （PEKS）, an indispensable part of searchable encryption, is stock-in- trade for both protecting data and providing operability of encrypted data. So far most of PEKS schemes have been established on Identity-Based Cryptography （IBC） with key escrow problem inherently. Such problem severely restricts the promotion of IBC-based Public Key Infrastructure including PEKS component. Hence, Certificateless Public Key Cryptography （CLPKC） is efficient to remove such problem. CLPKC is introduced into PEKS, and a general model of Certificateless PEKS （CLPEKS） is formalized. In addition, a practical CLPEKS scheme is constructed with security and efficiency analyses. The proposal is secure channel free, and semantically secure against adaptive chosen keyword attack and keyword guessing attack. To illustrate the superiority, massive experiments are conducted on Enron Email dataset which is famous in information retrieval field. Compared with existed constructions, CLPEKS improves the efficiency in theory and removes the key escrow problem.

The Cloud Storage Ciphertext Retrieval Scheme Based on ORAM

Due to its characteristics distribution and virtualization, cloud storage also brings new security problems. User＇s data is stored in the cloud, which separated the ownership from management. How to ensure the security of cloud data, how to increase data availability and how to improve user privacy perception are the key issues of cloud storage research, especially when the cloud service provider is not completely trusted. In this paper, a cloud storage ciphertext retrieval scheme based on AES and homomorphic encryption is presented. This ciphertext retrieval scheme will not only conceal the user retrieval information, but also prevent the cloud from obtaining user access pattern such as read-write mode, and access frequency, thereby ensuring the safety of the ciphertext retrieval and user privacy. The results of simulation analysis show that the performance of this ciphertext retrieval scheme requires less overhead than other schemes on the same security level.

Intelligent Server Management Framework over Extensible Messaging and Presence Protocol

With the increasing importance of cloud services worldwide, the cloud infrastructure and platform management has become critical for cloud service providers. In this paper, a novel architecture of intelligent server management framework is proposed. In this framework, the communication layer is based on the Extensible Messaging and Presence Protocol (XMPP), which was developed for instant messaging and has been proven to be highly mature and suitable for mobile and large scalable deployment due to its extensibility and efficiency. The proposed architecture can simplify server management and increase flexibility and scalability when managing hundreds of thousands of servers in the cloud era.

A Device for Simulating Soil Nutrient Extraction and Plant Uptake

In situ evaluating the availability of soil nutrients has been a challenge. In this study, a new type of Device for Simulating Soil Nutrient Extraction and Plant Uptake （DSSNEPU） and its operating procedures were introduced. The device consists of a sampling tube, a fluid supply system, a low pressure system, a tube sheath and an elution cylinder. The sampling tube was firstly soaked in the solution of 0.5 mol L-1 NaHCO3 and then buried into soils. The fluid supply system was connected to the sampling tube and the deionized water was supplied. During the period, low pressure system started a vacuum for 3 min every 10 rain interval. After extraction, the sampling tube was removed and the nutrients on the sampling tube were eluted with 0.5 tool L-1 HCl. The elution solution was used for nutrient measurement. The amounts of P and K extracted by DSSNEPU reached the maximal values after 4 h. No significant increases of P and K were observed for longer extraction duration. The optimal temperature for extracting P and K was 30 ℃ in this experiment. Extracted P and K were increased by 83.3% and 84.6% with the employment of low pressure system in comparison to those without employing low pressure system. Correlation analysis indicated that 1~ and K extracted by DSSNEPU were highly correlated with those by conventional chemical extraction and by plant uptake. The above results suggest that this device is applicable to assess the availability of nutrients in soils.