期刊文献+
共找到284篇文章
< 1 2 15 >
每页显示 20 50 100
Chinese Native Speakers' Counterfactuals Revisited
1
作者 LIANG Zheng yu (Foreign Languages Departmen, Guilin University of Electronic Technology, Guilin 541004, China) 《广西师范大学学报(哲学社会科学版)》 2002年第S2期13-33,共21页
This paper examines whether or not Chinese native speakers (CNSs) have difficulties in understanding English counterfactuals, whether CNSs have counterfactual reasoning problems in their own language, what the causes ... This paper examines whether or not Chinese native speakers (CNSs) have difficulties in understanding English counterfactuals, whether CNSs have counterfactual reasoning problems in their own language, what the causes of these difficulties may be, and the problems in teaching English subjunctives. It also proposes on how to improve CNSs’ English counterfactual comprehension. 展开更多
关键词 chinese native speakers COUNTERFACTUALS COMPREHENSION
下载PDF
Language Teaching and Intercultural Communication:Teaching Korean Grammar to Non-native Speakers
2
作者 Charmhun Jo A.K.M.Badrul Alam 《Journal of Literature and Art Studies》 2019年第12期1269-1274,共6页
Grounded upon the interactive relationship between intercultural communication(IC)and foreign language education and the recent gradual salience of communicative language teaching(CLT)in foreign language grammar learn... Grounded upon the interactive relationship between intercultural communication(IC)and foreign language education and the recent gradual salience of communicative language teaching(CLT)in foreign language grammar learning sectors,the study reported in this paper deals with the issue of teaching Korean grammar to non-native speakers in terms of teaching Korean as a foreign language(TKFL).This paper attempts to examine and analyze several Korean language textbooks prepared for foreign learners of Korean,which is used overseas,especially in Hong Kong(HK).It is also attempted to evaluate the textbooks in terms of CLT and communicative competence.By doing so,we can further understand the methods of Korean grammar instruction provided to foreigners as a second language or a foreign language. 展开更多
关键词 KOREAN GRAMMAR intercultural communication GRAMMAR translation method communicative language TEACHING non-native speakers
下载PDF
Native/Non-native English Speakers’Attitudes:Addressing Learners’Goals and Needs Towards Pronunciation Issues
3
作者 Anna Maria De Bartolo 《Journal of Literature and Art Studies》 2022年第1期87-102,共16页
The study attempts to explore native and non-native English speakers’attitudes towards accents and pronunciation-related issues.The sample group surveyed is composed of non-native English speakers,specifically,Italia... The study attempts to explore native and non-native English speakers’attitudes towards accents and pronunciation-related issues.The sample group surveyed is composed of non-native English speakers,specifically,Italian students studying at the University of Calabria(Italy)and native English speakers from Alberta University(Canada)and Florida Atlantic University(USA).An online link to a questionnaire was sent via email to all participants and was used as a research instrument to collect quantitative data.The research questions will investigate learners’attitudes in relation to the following aspects:accent and identity,beliefs about native/non-native accents,impact of pronunciation on communication,and learners’expectations towards pronunciation teaching.Firstly,mean scores in relation to the aforementioned aspects will be examined.Secondly,differences between native/non-native speakers’responses will be statistically analysed.Thirdly,non-native learners’responses will be correlated with their proficiency level in English to identify the extent to which language competence may affect learners’attitudes.The study aims to gain useful insights that may hopefully raise students and teachers’awareness of what models we expect learners to imitate and attain in the English language classroom,how appropriate and relevant these may be especially in the globalized English world where non-native speakers will increasingly use English in a diversity of forms to achieve their communicative goals.The preliminary results will be presented and pedagogical considerations suggested. 展开更多
关键词 accents and pronunciation ELF intercultural communication native/non-native English speakers attitudes
下载PDF
ELF Interactions Among Chinese, Greek, and Swiss Speakers of English
4
作者 Matgorzata Jedynak Ewa Jdzefowicz 《Sino-US English Teaching》 2014年第1期40-58,共19页
The paper concerns the issue of ELF (English as a lingua franca) in the European and Asian context. The authors start from a brief conceptual perspective to shed light on salient aspects related to ELF. Then, this p... The paper concerns the issue of ELF (English as a lingua franca) in the European and Asian context. The authors start from a brief conceptual perspective to shed light on salient aspects related to ELF. Then, this paper discusses the study investigating the interactions among NNS (non-native speakers) of English in the naturalistic settings, namely in Zhangjiajie (China), Masouri (Kalymnos/Greece), and Unterwasser (Switzerland). The main objective of the research based on the qualitative methodology was to analyze the ELF interactions from the linguistic point of view focusing on lexicogrammar and pragmatic features. The secondary objective was to establish whether the identified ELF features contributed to communication intelligibility. The obtained results indicated a few significant similarities with the Seidlhofer's list of the ELT characteristics. Furthermore, it was established in the study that the ELF features did not interfere with effective communication between interlocutors 展开更多
关键词 ELF (English as a lingua franca) NNS non-native speakers interactions ELF lexicogrammar andpragmatic features
下载PDF
The Intelligibility of Thai Speakers’ Pronunciation from Chinese Listeners’ Perspective
5
作者 陈容莹 《海外英语》 2020年第2期112-117,共6页
The intelligibility of Thai speakers’English pronunciation from Chinese listeners’perspectives have not been analyzed deeply in current researches.As is known to all,the interconnection between China and Thailand is... The intelligibility of Thai speakers’English pronunciation from Chinese listeners’perspectives have not been analyzed deeply in current researches.As is known to all,the interconnection between China and Thailand is greatly developed with the sup⁃port of‘One Belt and One Road initiative’.However,it is inevitable for non-native English speakers to encounter some pronuncia⁃tion problems,which would affect them to communicate with each other.As for Chinese English learners,Thai accent to some ex⁃tent would be a great challenge during the conversation with Thai speakers.In order to promote a better communication,it is neces⁃sary to analyze the origin of Thai speakers’English pronunciation problems.Therefore,this research based on the previous studies to categorize the common pronunciation problems among Thai speakers.However,there are numerous English learners in Thailand that have various language proficiency.In this respect,two Thai speakers with different IELTS scores have been selected for com⁃parison,and six postgraduate students in the Education University of Hong Kong are invited to serve as a listener.As a result,this research will base on the listeners’feedback to highlight some suggestions to enhance the intelligibility of Thai speakers’pronun⁃ciation. 展开更多
关键词 INTELLIGIBILITY Thai speakers English pronunciation chinese listeners communication
下载PDF
A Critique of Ali Shehadeh's Non-native Speakers'Production of Modified Comprehensible Output and Second Language Learning
6
作者 原田 《海外英语》 2012年第13期41-42,共2页
This study examined the NNSs' ability of modifying their interlanguage utterances in modified comprehensible output to give response to other-initiation and self-initiation,which was studied in both NS-NNS and NNS... This study examined the NNSs' ability of modifying their interlanguage utterances in modified comprehensible output to give response to other-initiation and self-initiation,which was studied in both NS-NNS and NNS-NNS interactions.It was the qualitative study by using two different tasks which were picture-dictation task and opinion-exchange task to collect the data.There were 32 participants whose age ranged of 22 to 37.The author proposed two hypotheses based on his expectation that NNS-NNS interactions would provide more opportunities for NNS participants to give comprehensible output for other-initiated clarification requests and self-initiated clarification attempts than NS-NNS interactions.The author was good at using numbers to illustrate and describe the data in his writing. 展开更多
关键词 NATIVE speaker(NS) non-native speaker(NNS) interla
下载PDF
In the Age of ‘World Englishes’,Native Speaker Teachers or Non-native Speaker Teachers?
7
作者 吴娟 《海外英语》 2016年第9期226-228,共3页
This paper attempts to argue that in the age of‘World Englishes', it is not necessary to differentiate native speaker teachers from non-native speaker teachers. It is concluded that non-native speaker teachers ca... This paper attempts to argue that in the age of‘World Englishes', it is not necessary to differentiate native speaker teachers from non-native speaker teachers. It is concluded that non-native speaker teachers can be as effective as their native colleagues and they have equal chance to achieve professional success, even though native speaker teachers have great advantages over non-native teachers in some aspects. It is time for employers, as well as ELT professionals to shut their eyes to the glaring differences between native speaker teachers and non-native speaker teachers and optimize such unique resources. 展开更多
关键词 world Englishes NATIVE speaker TEACHER non-native speaker TEACHER ENGLISH TEACHER
下载PDF
Academic Writing and the Challenges It Poses to Chinese Students in Anglophone Universities
8
作者 Yanmei Hu 《Sino-US English Teaching》 2005年第12期42-47,共6页
Academic literacy is the fundamental quality that scholars should possess in order to get socialized in their disciplinary communities, of which academic writing is one of the most important aspects. This article atte... Academic literacy is the fundamental quality that scholars should possess in order to get socialized in their disciplinary communities, of which academic writing is one of the most important aspects. This article attempts to summarize some common features of academic writing and the skills and background knowledge that are essential for successful writing. The next part focuses on the possible challenges that academic writing may pose on Chinese overseas students as they try to meet the requirements of the Western discourse communities. In the last part, it provides some recommendations to those who intend to study abroad and concludes that for both native and non-native speakers the learning of academic writing is a lifelong process of endless confliction and negotiation. 展开更多
关键词 Academic writing L1 L2 native speakers (NSs) non-native speakers (NNSs)
下载PDF
Theoretical Research of Chinese International Teaching in the Last Ten Years (2009-2018)
9
作者 于潇怡 《海外英语》 2021年第8期277-278,280,共3页
This review involved 234 theoretical research papers chosen from 13783 theses of Teaching Chinese to Speakers of Other Languages in China's Mainland during the period 2009-2018.Theoretical research mainly includes... This review involved 234 theoretical research papers chosen from 13783 theses of Teaching Chinese to Speakers of Other Languages in China's Mainland during the period 2009-2018.Theoretical research mainly includes two parts,theoretical analysis and theoretical application.The theoretical analysis and summary did not touch the core of the basic theory,and the macro height and depth were insufficient.Theoretical application rarely applied theories of this subject,mostly borrowed theories of other subjects to conduct experiments.There are more questions.The problems lead to doubt about the reliability of the thesis conclusion.For this reason,this review concludes with recommendations for Chinese researchers. 展开更多
关键词 Master of Teaching chinese to speakers of Other Languages master degree thesis theoretical research
下载PDF
A SURVEY:CHINESE COLLEGE STUDENTS’PERCEPTIONS OF NON-NATIVE ENGLISH TEACHERS 被引量:2
10
作者 陈晓茹 《Chinese Journal of Applied Linguistics》 2008年第3期75-82,128,共9页
本文是一份调查报告。通过对在校大学生的问卷调查和个别访谈,了解他们对中外英语教师的看法。调查的内容包括中外教师的语言能力、课堂教学能力及教师的人格魅力。结果表明,中外英语教师各有优势。外籍英语教师的语言能力,尤其在口语... 本文是一份调查报告。通过对在校大学生的问卷调查和个别访谈,了解他们对中外英语教师的看法。调查的内容包括中外教师的语言能力、课堂教学能力及教师的人格魅力。结果表明,中外英语教师各有优势。外籍英语教师的语言能力,尤其在口语交际能力和目的语文化方面有较高的认同度。但是,中国英语教师也有他们不可替代的地位。他们更加了解学生的学习策略和风格,能够较准确地预测学生的学习难点,因而能更好地帮助他们解决问题。值得指出的是,高年级的学生更加关注教师的专业水平和人格魅力。 展开更多
关键词 native speaker teacher (NST) non-native speaker teacher (NNST) perception English learning
原文传递
Unsuccessful letter–sound integration in English reading by native Chinese speakers: evidence from an event related potentials study 被引量:2
11
作者 Zhen Yang Cuicui Wang +2 位作者 Liping Feng Shifeng Li Sha Tao 《Science Bulletin》 SCIE EI CAS CSCD 2016年第24期1855-1864,共10页
Integrating letters and sounds are essential for successful reading in alphabetic languages. It remains unclear if native speakers of non-alphabetic languages integrate letters and sounds in reading an alphabetic lan-... Integrating letters and sounds are essential for successful reading in alphabetic languages. It remains unclear if native speakers of non-alphabetic languages integrate letters and sounds in reading an alphabetic lan- guage in the same way as native alphabetic readers do. Chinese is a morpho-syllabic system (each character cor- responds to one syllable) and contrasts sharply with alphabetic languages such as English. Several fMRI studies have shown that native Chinese speakers apply their native language system to read English words. By using the cross- modal mismatch negativity (MMN) paradigm, we directly investigated letter-sound integration for reading in English among native Chinese speakers. To investigate the effect of native language background on letter-sound integration in second language reading, a group of native Korean English learners served as a comparison group. We compared MMN responses between an auditory only condition (only vowels presented) and two audiovisual conditions (AV0, vowel presented synchronously with the corresponding letter; AV200, the letter presented 200 ms before the corresponding vowel) for both native Chinese and native Korean speakers. Native Chinese speakers demonstrated significantly attenuated MMN amplitudes in audiovisual conditions compared with the auditory only condition, regardless of their phonological decoding speed. In con- trast, native Korean speakers showed amplified amplitude MMN in AV200 compared with that in the auditory only condition. The results suggest that native language may shape the brain responses of second language learners to reading a second language in the early stages. Native non- alphabetic language speakers may be unable to use visual information to facilitate their phonological processing in the early stage while naT:lye alphabetic language speakers are capable of integrating letter sounds automatically. 展开更多
关键词 Letter-sound integration Secondlanguage reading Native chinese speakers NativeKorean speakers English reading
原文传递
"Nativeness" and Intelligibility:Impacts of Intercultural Experience Through English as a Lingua Franca on Chinese Speakers' Language Attitudes 被引量:5
12
作者 王颖 Jennifer JENKINS 《Chinese Journal of Applied Linguistics》 2016年第1期38-58,132,133,共23页
This paper investigates the impacts of intercultural experience through English as a lingua franca (ELF) on language attitudes, with the focus on Chinese speakers' narratives of ELF experience in relation to their ... This paper investigates the impacts of intercultural experience through English as a lingua franca (ELF) on language attitudes, with the focus on Chinese speakers' narratives of ELF experience in relation to their views of Englishes. The data retrieved through 769 questionnaires and 35 interviews with Chinese users of English revealed the impacts in four aspects. First, the lack of ELF experience helps to maintain the assumption that conformity to native English is necessary for interactants to understand each other. Second, ELF experience triggers the question about the exclusive connection between nativeness and intelligibility. Third, it raises challenges to the exclusive relevance of native English for successful intercultural communication. Fourth, it helps to develop an awareness of intercultural communication strategies as important for communicative effectiveness in the context of the diversity of English. Attitudes revealed in the four aspects all point to a concern with the issue what is intelligible English. This paper thus discusses intelligibility in relation to (non-) nativeness and the role of intercultural experience in making sense of the issue of intelligibility, which leads to the exploration of pedagogical implications of this study. 展开更多
关键词 nativeness INTELLIGIBILITY English as a lingua franca chinese speakers intercultural experience language attitudes
原文传递
Native-speakerism in China:An Investigation of Foreign Language Education Policy and Learners’Attitudes
13
作者 FENG Jing ZHANG Ying-xian 《Journal of Literature and Art Studies》 2022年第12期1275-1303,共29页
With the development of globalization,the use of English is no longer restricted to native speaker(NS)but also widely spread to non-native speaker(NNS).The importance of English learning is also acknowledged by Expand... With the development of globalization,the use of English is no longer restricted to native speaker(NS)but also widely spread to non-native speaker(NNS).The importance of English learning is also acknowledged by Expanding and Outer Circle,and English as a foreign language(EFL)education plays a significant role in China’s education.Admitting the fact that non-native English teachers(NNESTs)take up a large proportion of English teachers,English language teaching(ELT)is still greatly influenced by native-speakerism.This research aims to investigate language ideologies reflected in Chinese foreign language education policy(FLEP)at higher education level,and Chinese English learners’attitudes towards native-speakerism and English teachers.A mixed method of policy analysis and survey is adopted in this research.After conducting analysing two FLEPs in higher education level,it is found that linguistic instrumentalism is the prominent language ideology,although native-speakerism and standard English ideology is implicitly demonstrated.Questionnaire is used to investigate 58 Chinese English learners’attitudes,revealing that most participants do not demonstrate bias towards either NESTs or NNESTs.Instead,the strengths and weaknesses of both NEST and NNEST are identified,though participants adhere to native-speakerism in terms of English variety.Overall,English learner’s attitudes are consistent with language ideologies in FLEPs.This research may provide implications for future studies on addressing native-speakerism in Chinese FLEPs,as well as relationship of students’attitudes and language policies. 展开更多
关键词 native-speakerism Native English speaker Teacher(NEST) non-native English speaker Teacher(NNEST) Foreign Language Education Policy(FLEP) language ideology attitude
下载PDF
新文科背景下地方应用型高校汉语国际教育专业实践教学研究--以黄山学院为例
14
作者 时雯雯 沈昌明 《黄山学院学报》 2024年第2期138-140,共3页
黄山学院汉语国际教育专业坚持地方性、应用型、国际化方针,实践教学地位日益突出,但新文科背景下,其实践教学仍存在教学队伍建设缺乏合理规划、实践教学形式不够丰富、实践教学质量考核机制不健全等问题,基于此提出相关对策:将立德树... 黄山学院汉语国际教育专业坚持地方性、应用型、国际化方针,实践教学地位日益突出,但新文科背景下,其实践教学仍存在教学队伍建设缺乏合理规划、实践教学形式不够丰富、实践教学质量考核机制不健全等问题,基于此提出相关对策:将立德树人落到实处,着力打造特色“金课”,构建交叉融合课程体系,培养高素质师资队伍,完善实习实训体系,鼓励学生参赛、考证,以加强实践教学质量管控。 展开更多
关键词 新文科 汉语国际教育 实践教学
下载PDF
元话语视角下的汉语二语者学术写作能力研究
15
作者 王帅 康可意 《国际中文教育(中英文)》 2024年第3期87-97,共11页
本文对比分析了汉语母语者与母语为韩语的汉语二语者在汉语学术语篇中元话语使用的情况,进而揭示了两个群体在学术写作能力上的差异。调查结果显示:①汉语母语者和二语者在元话语类型的选择上呈现相对一致的趋势,但二语者在元话语使用... 本文对比分析了汉语母语者与母语为韩语的汉语二语者在汉语学术语篇中元话语使用的情况,进而揭示了两个群体在学术写作能力上的差异。调查结果显示:①汉语母语者和二语者在元话语类型的选择上呈现相对一致的趋势,但二语者在元话语使用的整体密度和形式多样性方面均低于母语者,且在部分元话语类型中差异显著;②相较于汉语母语者,二语者学术语篇中元话语的运用存在充分性不足、适切性不足及多样性不足等问题,这些问题在一定程度上影响了二语者学术语篇的质量。针对上述结果,本文提出了提升二语者元话语使用及学术写作能力的相关建议。 展开更多
关键词 元话语 学术语篇 学术写作能力 汉语二语者
下载PDF
The Role and Value of Sociolinguistics in English Language Teaching
16
作者 Fenhua Guo 《Journal of Contemporary Educational Research》 2024年第8期193-201,共9页
This paper aims to explore how the study of sociolinguistics can benefit teachers,particularly in the context of teaching English as a Foreign Language(EFL)in China.The article will first examine how sociolinguistic k... This paper aims to explore how the study of sociolinguistics can benefit teachers,particularly in the context of teaching English as a Foreign Language(EFL)in China.The article will first examine how sociolinguistic knowledge can reshape teachers’perceptions of“English,”focusing on aspects such as English varieties,World Englishes,and Chinese English.Following that,the article discusses the necessity of rethinking current practices in English language teaching,including the nativeness paradigm and the concept of communicative competence based on a reconceptualized view of“English.”Additionally,the discussion will focus on how teachers,informed by sociolinguistic awareness of non-native teachers’identities and teacher agency,can address and resolve existing challenges in EFL teaching.Finally,the article will conclude by summarizing the key issues discussed and highlighting the significance of studying sociolinguistics for language practitioners in China. 展开更多
关键词 World Englishes chinese English English language teaching Nativeness non-native English-speaking teachers
下载PDF
汉硕留学生二语习得课教学设计与实施——基于“翻转课堂”教学理念
17
作者 高珊 《现代语文》 2024年第1期90-95,共6页
以汉语国际教育专业硕士留学生的培养为出发点,基于“翻转课堂”教学理念,设计并实施第二语言习得课程教学。教学设计包括课前、课中和课后三个部分,其中,在课前阶段,教师准备材料分享、学生自主学习;在课中阶段,教师指导学生完成报告... 以汉语国际教育专业硕士留学生的培养为出发点,基于“翻转课堂”教学理念,设计并实施第二语言习得课程教学。教学设计包括课前、课中和课后三个部分,其中,在课前阶段,教师准备材料分享、学生自主学习;在课中阶段,教师指导学生完成报告、讨论、辩论等;在课后阶段,布置讨论和评价任务。三个阶段的有机结合,可以实现“以学生为中心”的二语习得课程教学。经过两个学期的实施,通过问卷调查发现,学生对“翻转课堂”教学模式基本持肯定态度;同时,也对教学模式的应用细节提出了建议。 展开更多
关键词 “翻转课堂” 二语习得课程 汉语国际教育硕士
下载PDF
国际中文教育背景下的对外书法教学发展路径研究
18
作者 杨文琪 池程远 《福建技术师范学院学报》 2024年第1期128-136,共9页
对外书法教学发展路径的探讨,也是对外书法教学的整体回顾、深入理解、再度诠释与理论重塑。对外书法教学的逻辑进路是“由浅入深”的,即从文化教学迈向汉字教学,再进一步至书法专业教学。国际中文教育新形势下的教学实践,应试图再度激... 对外书法教学发展路径的探讨,也是对外书法教学的整体回顾、深入理解、再度诠释与理论重塑。对外书法教学的逻辑进路是“由浅入深”的,即从文化教学迈向汉字教学,再进一步至书法专业教学。国际中文教育新形势下的教学实践,应试图再度激发汉字书法的“文化活力”,在文化教学、汉字教学、书法专业教学三者联结构成的畛域内,重点聚焦“文化”的感染力与影响力,重新扮演中外交流的“文化使者”,从而实现进一步发展。当国际中文教育所依托的叙事语境发生了变化,教学思维也必须随之而改变,并要适应新情境,在技术与心理上做好充分应对。 展开更多
关键词 国际中文教育 对外书法教学 发展路径
下载PDF
深度学习理念下以能力培养为取向的教学设计与实施——以汉语国际教育硕士研究生课程为例
19
作者 贺莉娜 《国际中文教育(中英文)》 2024年第2期79-89,共11页
本文以深度学习理论为指导,对“汉语作为第二语言教学”研究生课程进行完整设计,并从实践层面检验教学效果,通过问卷调查、师生座谈、教师访谈、教师自传性教学经历记录等方式获得师生层面的双向反馈,以期为汉语国际教育硕士培养的相关... 本文以深度学习理论为指导,对“汉语作为第二语言教学”研究生课程进行完整设计,并从实践层面检验教学效果,通过问卷调查、师生座谈、教师访谈、教师自传性教学经历记录等方式获得师生层面的双向反馈,以期为汉语国际教育硕士培养的相关教学提供借鉴。研究结果显示,深度学习理论指导下的“汉语作为第二语言教学”研究生课程教学效果良好,能够帮助学生体会到实在的获得感,且能够促进学生理论知识学习向实践应用能力的转化。 展开更多
关键词 深度学习 研究生教学 课程设计 汉语国际教育 能力培养
下载PDF
语音识别中的一种说话人聚类算法 被引量:4
20
作者 肖述才 欧智坚 王作英 《中文信息学报》 CSCD 北大核心 2005年第4期84-88,共5页
本文介绍了稳健语音识别中的一种说话人聚类算法,包括它在语音识别中的作用和具体的用法,聚类中常用的特征、距离测度,聚类的具体实现步骤等。我们从两个方面对该算法的性能进行了测试,一是直接计算句子聚类的正确率,二是对说话人自适... 本文介绍了稳健语音识别中的一种说话人聚类算法,包括它在语音识别中的作用和具体的用法,聚类中常用的特征、距离测度,聚类的具体实现步骤等。我们从两个方面对该算法的性能进行了测试,一是直接计算句子聚类的正确率,二是对说话人自适应效果的改进的作用,即比较使用此算法后系统性能的改进进行评价。实验表明:在使用GLR距离作为距离测度的时候,该算法对句子的聚类正确率达85·69%;在识别实验中,该聚类算法的使用,使得用于说话人自适应的数据更加充分,提高了自适应的效果,系统的误识率已经接近利用已知说话人信息进行自适应时的误识率。 展开更多
关键词 计算机应用 中文信息处理 说话人聚类 说话人自适应 语音识别
下载PDF
上一页 1 2 15 下一页 到第
使用帮助 返回顶部