首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   192篇
  免费   2篇
  国内免费   1篇
教育   129篇
科学研究   22篇
各国文化   5篇
体育   3篇
文化理论   3篇
信息传播   33篇
  2023年   3篇
  2022年   8篇
  2021年   11篇
  2020年   7篇
  2019年   12篇
  2018年   8篇
  2017年   12篇
  2016年   12篇
  2015年   8篇
  2014年   11篇
  2013年   26篇
  2012年   10篇
  2011年   14篇
  2010年   4篇
  2009年   10篇
  2008年   5篇
  2007年   4篇
  2006年   4篇
  2005年   6篇
  2004年   6篇
  2003年   2篇
  2002年   3篇
  2001年   1篇
  1998年   1篇
  1996年   1篇
  1994年   1篇
  1993年   1篇
  1991年   1篇
  1989年   1篇
  1981年   1篇
  1978年   1篇
排序方式: 共有195条查询结果,搜索用时 9 毫秒
91.
Blockchain plays a vital task in cybersecurity. With the exerted efforts for realising large-scale quantum computers, most current cryptographic mechanisms may be hacked. Accordingly, we need a quantum tool utilised for designing blockchain frameworks to have the ability to be executed in the level of digital computers and resist the probable attacks from both digital and quantum computers. Quantum walks may be utilised as a quantum-inspired model for designing new cryptographic algorithms. In this paper, we present a new authentication and encryption protocol based on quantum-inspired quantum walks (QIQW). The proposed protocol is utilized to build a blockchain framework for secure data transmission among IoT devices. Instead of using classical cryptographic hash functions, quantum hash functions based on QIQW are employed for linking blocks of the chain. The main advantages of the presented framework are helping IoT nodes to effectively share their data with other nodes and full control of their records. Security analysis demonstrates that our proposed protocol can defend against message attack and impersonation attacks, thus ensuring secure transmission of data among IoT devices.  相似文献   
92.
Cells and cell-free solutions of the culture filtrate of the bacterial symbiont, Xenorhabdus nematophila taken from the entomopathogenic nematode Steinernema carpocapsae in aqueous broth suspensions were lethal to larvae of the diamondback moth Plutella xylostella. Their application on leaves of Chinese cabbage indicated that the cells can penetrate into the insects in the absence of the nematode vector. Cell-free solutions containing metabolites were also proved as effective as bacterial cells suspension. The application of aqueous suspensions of cells of X. nematophila or solutions containing its toxic metabolites to the leaves represents a possible new strategy for controlling insect pests on foliage.  相似文献   
93.
The study examined the relationship of extraversion (E), neuroticism (N), psychoticism (P), academic self‐concept and locus of control to academic attainment of lower secondary school pupils in a cross‐cultural context. Measures of E, N, P, academic self‐concept, locus of control and academic attainment were taken from 120 pupils (60 boys, 60 girls) of Standard 7 in a middle school in Bophuthatswana (Southern African region). The analysis of results revealed that E, N and P are significantly negatively related to academic attainment, while academic self‐concept and internality are significantly positively associated with measures of academic attainment. No significant sex differences were found. It was also observed that mean E and N scores of the subjects of this study were significantly lower than those given in Eysenck and Eysenck's (1975) normative data for English children of the same age.  相似文献   
94.
Asia Pacific Education Review - In the provision of massive open online courses (MOOCs), cloud computing services enable students to synchronize their study materials anywhere, anytime, and using...  相似文献   
95.
One form of educational inequality is the disparity that exists between urban and rural settings. Equal distribution of quality education is a challenge for developing countries due to the unavailability of resources. Various approaches to equal distribution are distance learning, telecast learning and e-learning; however, these approaches cannot achieve the desired objectives due to their limitations. This research aimed to investigate the interesting question of whether mobile technology can bring urban and rural settings closer together. A mobile application for learning Urdu grammar was designed to measure the learning gains of fourth-grade students at two different schools from urban and rural settings. A quantitative technique, the quasi-experimental pre-test and post-test method, was used to measure the effectiveness of the mobile application. The comparison of the students’ performances at the urban and rural schools illustrated the role of mobile technology in mitigating the educational gap. The present study provides evidence that children from different social backgrounds may benefit equally from mobile technology.  相似文献   
96.
Syzygium campanulatum Korth is a plant, which is a rich source of secondary metabolites (especially flavanones, chalcone, and triterpenoids). In our present study, three conventional solvent extraction (CSE) techniques and supercritical fluid extraction (SFE) techniques were performed to achieve a maximum recovery of two flavanones, chalcone, and two triterpenoids from S. campanulatum leaves. Furthermore, a Box-Behnken design was constructed for the SFE technique using pressure, temperature, and particle size as independent variables, and yields of crude extract, individual and total secondary metabolites as the dependent variables. In the CSE procedure, twenty extracts were produced using ten different solvents and three techniques (maceration, soxhletion, and reflux). An enriched extract of five secondary metabolites was collected using n-hexane:methanol (1:1) soxhletion. Using food-grade ethanol as a modifier, the SFE methods produced a higher recovery (25.5%?84.9%) of selected secondary metabolites as compared to the CSE techniques (0.92%?66.00%).  相似文献   
97.
ABSTRACT

The present study was conducted to assess distance learning students’ perceptions about location and physical set up of libraries, collections, resources, and services rendered at thirty-four regional campuses as well as main campus libraries network of Allama Iqbal Open University (AIOU) all over Pakistan. During the spring semester of 2007, a questionnaire was mailed to 250 randomly selected students enrolled in eleven postgraduate programs throughout the country. The response rate was 61.2%, which was made up of 43.1% females and 56.9% males. A majority of the respondents were dissatisfied with the virtual reference services, online database facilities, interlibrary loan, library membership, and borrowing of library material from the AIOU libraries. They were satisfied with the location and physical setup of the libraries, the collections, and the resources of the libraries. The study revealed that most of the respondents used the libraries during workshops as well as for research purposes. The statistical analysis (t = 0.550, Sig. = 0.970) showed that there was no significant difference between the opinion of females and males. The data were analyzed using Statistical Package for Social Sciences (SPSS) for Windows version 10.0.  相似文献   
98.
This research aims to provide an analytic and critical review of research on information seeking anxiety (ISA) with a view to inform the information professionals, especially those engaged in information literacy instructions about the existing situation. This study established the background of the proposed phenomenon, provided integrated analysis of the available research, and discussed the theoretical and practical implications of ISA on information services, especially information literacy instruction. Although the results from previous studies were not comparable, directly due to varied geographical contexts and research methods, it was nevertheless possible to draw some common conclusions regarding the users’ anxiety related to information seeking tasks. This review overwhelmingly indicated the manifestation and prevalence of ISA among students in the digital environment. Some personal and academics variables of students appear to be correlated with ISA. The results of reviewed studies indicated the necessity for a need-based information literacy curriculum for alleviation of anxiety related to students’ information-seeking tasks.  相似文献   
99.
ABSTRACT

This study explores the current status and features of Pakistan's academic library Web sites. A checklist describing features and content was prepared based on a review of the literature related to academic libraries’ Web sites. Then, all 85 library Web sites of Pakistani universities and degree-awarding institutions recognized by the Higher Education Commission (HEC) of Pakistan were surveyed and analyzed using the checklist. Interviews with library professionals were conducted to learn more about the problems and issues with building and maintaining library Web sites. Results indicate that Pakistani academic library Web sites have effective features such as contrasting color schemes, easily readable text, minimal use of horizontal scrolling, and English-language text. Staff information, OPACs, and navigation features are also widely found on the Web sites. Features found less frequently include the use of Web 2.0 technologies, Web site aid tools, information about library buildings, and general library information. By offering information about the status of Pakistani academic library Web sites, the study can serve as a foundation for discussion between libraries and other parts of the university, as well as a benchmark for evaluating the progress of academic library Web sites in Pakistan  相似文献   
100.
Described here is a study of how students actively read electronic journal papers to prepare for classroom discussions. Eighteen students enrolled in a graduate course participated in this study; half of them read the documents privately, while the other half shared their readings. These readers were digitally monitored as they read, annotated, and shared the electronic (e-) documents over a course of several weeks during a semester. This monitoring yielded a comprehensive data bank of 60 e-documents (with 1923 markings), and 56 computer logs. Using semi-structured interviews, the reading, marking, and navigational activities of the participating readers were analyzed in detail. Under scrutiny were a range of activities that the subjects carried out. Analyses of the data revealed the types of markings that the users employ, and the ways in which those marking were placed. A derivation of the user-perceived functions of the marking structures was then carried out. The findings then lead to several implications for informing the design of reading and marking applications in digital libraries.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号