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排序方式: 共有263条查询结果,搜索用时 10 毫秒
71.
Ahmed A. Abd El-Latif Bassem Abd-El-Atty Irfan Mehmood Khan Muhammad Salvador E. Venegas-Andraca Jialiang Peng 《Information processing & management》2021,58(4):102549
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
72.
Hong-Li Li Jinde Cao Haijun Jiang Ahmed Alsaedi 《Journal of The Franklin Institute》2018,355(13):5771-5789
This paper considers the finite-time synchronization problem for a class of fractional-order complex dynamical networks (FOCDNs). By utilizing the properties of fractional calculus and fractional-order comparison principle, we propose a new lemma. Base on the new lemma, some analysis techniques and algebraic graph theory method, some novel criteria are given to ensure finite-time synchronization of FOCDNs, and the upper bound of the setting time for synchronization is estimated. At last, numerical simulations are given to verify the effectiveness of the obtained results. 相似文献
73.
Judith Lederman Norman Lederman Selina Bartels Juan Jimenez Mark Akubo Shereen Aly Chengcheng Bao Estelle Blanquet Ron Blonder Mariana Bologna Soares de Andrade Catherine Buntting Mustafa Cakir Heba EL-Deghaidy Ahmed ElZorkani Estelle Gaigher Shuchen Guo Arvi Hakanen Soraya Hamed Al-Lal Cigdem Han-Tosunoglu Annemarie Hattingh Anne Hume Serhat Irez Gillian Kay Ozgur Kivilcan Dogan Kerstin Kremer Pi-Chu Kuo Jari Lavonen Shu-Fen Lin Cheng Liu Enshan Liu Shiang-Yao Liu Bin Lv Rachel Mamlok-Naaman Christine McDonald Irene Neumann Yaozhen Pan Eric Picholle Ana Rivero García Carl-Johan Rundgren David Santibáñez-Gómez Kathy Saunders Renee Schwartz Frauke Voitle Jakob von Gyllenpalm Fangbing Wei Jocelyn Wishart Zhifeng Wu Huang Xiao Yalcin Yalaki Qiaoxue Zhou 《科学教学研究杂志》2019,56(4):486-515
Although understandings of scientific inquiry (as opposed to conducting inquiry) are included in science education reform documents around the world, little is known about what students have learned about inquiry during their elementary school years. This is partially due to the lack of any assessment instrument to measure understandings about scientific inquiry. However, a valid and reliable assessment has recently been developed and published, Views About Scientific Inquiry (VASI; Lederman et al. [2014], Journal of Research in Science Teaching, 51, 65–83). The purpose of this large-scale international project was to collect the first baseline data on what beginning middle school students have learned about scientific inquiry during their elementary school years. Eighteen countries/regions spanning six continents including 2,634 students participated in the study. The participating countries/regions were: Australia, Brazil, Chile, Egypt, England, Finland, France, Germany, Israel, Mainland China, New Zealand, Nigeria, South Africa, Spain, Sweden, Taiwan, Turkey, and the United States. In many countries, science is not formally taught until middle school, which is the rationale for choosing seventh grade students for this investigation. This baseline data will simultaneously provide information on what, if anything, students learn about inquiry in elementary school, as well as their beginning knowledge as they enter secondary school. It is important to note that collecting data from all of the approximately 200 countries globally was not humanly possible, and it was also not possible to collect data from every region of each country. The results overwhelmingly show that students around the world at the beginning of grade seven have very little understandings about scientific inquiry. Some countries do show reasonable understandings in certain aspects but the overall picture of understandings of scientific inquiry is not what is hoped for after completing 6 years of elementary education in any country. 相似文献
74.
Jamy Stillman Kathryn Struthers Ahmed Erika Castañeda-Flores 《The Educational forum》2013,77(4):432-452
In this article, we share findings from a 3-year project in which novice teacher educators participated in Freirean culture circles and Boalian Theatre of the Oppressed (teatro) in order to critically explore the work of justice-oriented teacher education. Anchored in one of the project’s most resonant scenarios, the article illustrates how teatro cultivated among participants courage to confront injustice, while also shedding light on the complexities teacher educators may face when attempting to facilitate teacher learning, particularly when such learning is centered on equity and justice. 相似文献
75.
The major aim of power quality (PQ) enhancing techniques is to maintain a specified voltage magnitude at a desired frequency for sensitive loads irrespective of faults on the power distribution network. The dynamic voltage restorer (DVR) is a device used to mitigate voltage sags to regulate load voltage. This paper presents a mathematical model for leading series voltage injection to mitigate sags thereby achieving the improvement of the utility power factor as well as power sharing between the DVR and utility. The power sharing will be as per requirement to compensate the sags considering the available distributed generation (DG). The approach of mitigating voltage sags using the concept of leading series voltage injection is suitable for those locations where phase shift in the voltage will not cause any problem. The MATLAB/SIMULINK SimPowerSystem toolbox has been used to obtain simulation results to verify the proposed mathematical model. 相似文献
76.
77.
Ahmed Ibrahim Mark W. Aulls Bruce M. Shore 《International Journal of Science Education》2016,38(16):2450-2476
Sociocognitive theory [Bandura, A. (1986). Social foundations of thought and action: A social cognitive theory. Englewood Cliffs, NJ: Prentice Hall; Bandura, A. (1989). Human agency in social cognitive theory. American Psychologist, 44, 1175–1184. doi:10.1037/0003-066x.44.9.1175; Bandura, A. (1991). Social cognitive theory of self-regulation. Organizational Behavior and Human Decision Processes, 50, 248–287. doi:10.1016/0749-5978(91)90022-L] accords high importance to the mechanisms of human agency and how they are exercised through self-efficacy. In this paper, we developed and validated the McGill Self-Efficacy For Inquiry Engagement (McSELFIE) instrument with undergraduate students in natural science disciplines. We defined inquiry engagement as carrying out the practices of science (POS) that are supported by students’ personality characteristics (SPCs) and that result in achieving inquiry-learning outcomes (ILOs). Based on these theoretical perspectives, the McSELFIE is a 60-item, learner-focused survey that addresses three components that are theoretically important for engaging in scientific inquiry: (a) SPCs, (b) ILOs, and (c) POS. Evidence for construct and content validity were obtained by using experts’ judgments and confirmatory factor analysis with a sample of 110 undergraduate students enrolled in science disciplines. Internal consistency of the factors and instrument was also examined. The McSELFIE instrument is a reliable and valid instrument for measuring science undergraduate students’ self-efficacy for inquiry engagement. Matched pairs analyses were conducted among the instruments’ factors. Students reported the highest self-efficacy for openness, applying knowledge, and carrying out investigations. Students reported the lowest self-efficacy for extraversion, understanding metacognitive knowledge, and planning investigations. Theoretical and practical implications are discussed. 相似文献
78.
Brain type natriuretic peptide (BNP)—A marker of new millennium in diagnosis of congestive heart failure 总被引:1,自引:0,他引:1
Arun Raizada Suman Bhandari Muzaiyan Ahmed Khan Harsh Vardhan Singh Sherin Thomas Vikram Sarabhai Neelima Singh Naresh Trehan 《Indian journal of clinical biochemistry : IJCB》2007,22(1):4-9
The burden of disease in patients with congestive heart failure is high. The future of BNP looks promising as it may be a
better diagnostic tool for the diagnosis of CHF in developing countries in new millennium. Natriuretic peptide hormones, a
family of vasoactive peptides with many favourable physiological properties, have emerged as important contenders for development
of diagnostic tools and therapeutic agents in cardiovascular disease. Measurement of B-type natriuretic peptide has become
as an easy-to-perform bedside test. The clinical and diagnostic significance of the measurement of plasma Nt-proBNP in the
diseases of the cardiovascular system with particular emphasis on the assessment of patients with heart failure and their
effects on predicting survival rate. The plasma levels of Nt-proBrain Natriuretic peptide responds more vigorously after myocardial
infarction than those of other natriuretic peptides. This article is an attempt to give a short overview on the utility of
BNP-blood levels for the diagnosis and treatment of heart failure 相似文献
79.
Ahmed Maher Khafaga Shehata Mohammed Fathy Mahmoud Elgllab 《The Journal of Academic Librarianship》2019,45(4):386-393
The purpose of this paper is to report the findings of a study of library anxiety among a group of Arab students in Saudi Arabia and Egypt. The paper also investigated the factors that affect the students' level of anxiety while using academic libraries. The study tried to compare the difference in the level of anxiety in the two countries using a scale (LLPB) developed by the researchers which fit the culture in the Arab region. The study adopted a mixed methods approach. Semi-structured interviews were conducted with several students in Saudi Arabia and Egypt to determine the main factors that lead to having a level of anxiety in the libraries. In the second stage, a questionnaire was sent to students to measure what factors have a greater impact on the level of anxiety. The data showed that Egyptian students are more anxious about using the libraries than the Saudi students. The results also indicated that there is a need to train students on how to use the libraries and also change students' perception regarding the library to reduce the level of anxiety. This study was conducted in Egypt and Saudi Arabia the level of library anxiety and the factors that may affect the students may vary in other countries. 相似文献
80.