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101.
Chip morphology predictions in metal cutting have always been challenging because of the complexity of the various multiphysical phenomena that occur across the tool-chip interface. An accurate prediction of chip morphology is a key factor in the assessment of a particular machining operation with regard to both tool performance and workpiece quality. Although finite element (FE) models are being developed over the last two decades, their capabilities in modeling correct material flow around the tool tip with shear localization are very limited. FE models with an arbitrary Lagrangian Eulerian (ALE) approach are able to simulate correct material flow around the tool tip. However, these models are unable to predict any shear localization based on material flow criteria. On the other hand, FE models with a Lagrangian formulation can simulate shear localization in the chip segments; they need to make use of a mesh-based chip separation criterion that significantly affects material flow around the tool tip. In this study a mesh-free method viz. smoothed particles hydrodynamics (SPH) is implemented to simulate shear localization in the chip while machining hardened steel. Unlike other SPH models developed by some researchers, this model is based on a renormalized formulation that can consider frictional stresses along the tool-chip interface giving a realistic chip shape and material flow. SPH models with different cutting parameters are compared with the traditional FE models and it has been found that the SPH models are good for predicting shear localized chips and do not need any geometric or mesh-based chip separation criteria.  相似文献   
102.
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   
103.
Environmental pollution affects the quality of pedosphere, hydrosphere, atmosphere, lithosphere and biosphere. Great efforts have been made in the last two decades to reduce pollution sources and remedy the polluted soil and water resources. Phytoremediation, being more cost-effective and fewer side effects than physical and chemical approaches, has gained increasing popularity in both academic and practical circles. More than 400 plant species have been identified to have potential for soil and water remediation. Among them, Thlaspi, Brassica, Sedum alfredii H., and Arabidopsis species have been mostly studied. It is also expected that recent advances in biotechnology will play a promising role in the development of new hyperaccumulators by transferring metal hyperaccumulating genes from low biomass wild species to the higher biomass producing cultivated species in the times to come. This paper attempted to provide a brief review on recent progresses in research and practical applications of phytoremediation for soil and water resources. Project supported by the Higher Education Commission, Government of Pakistan for the faculty training under the R & D Project “Strengthening Department of Soil Science and Soil and Water Conservation” at the University of Florida, USA, a grant from the St. Lucie River Water Initiative (SFWMD contract No. OT060162), USA, in part, and the Program for Changjiang Scholars and Innovative Research Team in University (No.IRT0536), China  相似文献   
104.
105.
The references cited in scientific articles are as important as any other part of the paper, because of their usefulness to the scientific community and to abstracting and indexing services and citation databases. I studied inaccuracies in references and in‐text citations in sample of 97 of the 519 peer‐reviewed journals accredited by the Iranian National Commission for Journal Accreditation Policy (Ministry of Research, Science and Technology). The target journals published 2,980 articles with 74,577 cited references and 108,151 in‐text citations. The results showed 36.6% as the average percentage error rate (range 5.6% to 61.3%). The mean number of errors in cited reference and in‐text citations was 2.7 per article, and the mean number of errors per journal was 690. For the entire sample of articles, 4,369 in‐text citations did not match any source in the list of references (4%), and 8,683 cited references did not match any in‐text citation (11.6%). The stakeholders in scholarly communication, especially authors, pay insufficient attention to the accuracy of bibliographic references. Peer‐reviewed journals should encourage the use of standardized journal policies and quality‐control measures regarding peer review, data quality and accuracy.  相似文献   
106.
This paper first reviews the literature on school-university partnerships to evaluate and describe challenges and paradigms of Japanese approaches to school-university partnerships in theory and practice. Secondly, it clarifies the role of three-year school-university partnership between the Nagoya University and the Tokai City Board of Education in the central Japan for creating an effective environment in schools for teachers to learn from each other and for developing more learning-centered education that focuses on the real needs of students. From this study it can be claimed that more effective relationships between Japanese school teachers and university researchers can be established through developing collaborative a school-based research framework especially through the process of jugyou kenkyuu (lesson study).  相似文献   
107.
Despite the significant role of oral presentation in the academic context, many university students evade opportunities for participation due to low self-efficacy. The present study has been conducted to compare oral presentation self-efficacy of English as a Foreign Language (EFL) learners with undergraduates and postgraduates of Non-EFL majors, and to investigate the relationship of this construct with their teaching and prior academic oral presentation experiences as two modes of Bandura’s [(1995). Exercise of personal and collective efficacy in changing societies. In A. Bandura (Ed.), Self-efficacy in changing societies (pp. 1–45). New York: Cambridge University Press] mastery experience. Extracting the oral presentation sub-skills from the literature, an oral presentation self-efficacy questionnaire with 38 five-Likert scale items was constructed. A two-way between-group ANOVA was run on the responses of a total 48 postgraduates (25 EFL and 23 Non-EFL) and 63 undergraduates (28 EFL and 35 Non-EFL) selected randomly from two of the universities in Iran. The results indicated no difference between EFL and Non-EFL students, whether at undergraduate or postgraduate level, in terms of their oral presentation self-efficacy. Spearman’s correlation coefficient, however, showed a strong positive correlation between the two modes of mastery experience and oral presentation self-efficacy (r?=?.44, n?=?111, P?r?=?.42, n?=?111, P?相似文献   
108.
This study analyzes the current state of gold Open Access (OA) in India based on papers published in the Web of Science indexed journals. It specifically focuses on research output published in OA journals and examines the difference between gold OA and general research output for papers authored by Indian researchers. In order to analyze the Indian contribution of gold OA literature and compares with other countries, Web of Science?-Core Collection was used. There is an increasing trend of contributing research papers in OA journals by Indian researchers. Among the top 20 publishing countries India ranks 10th place in terms of the general research output, but secures 8th place in terms of gold OA papers. However, India's position in terms of share of gold OA publications is relatively higher than other leading countries of the world. Researchers in India mostly prefer to contribute their gold OA papers in Indian journals rather foreign journals and the proportion of gold OA research output in Clinical, Preclinical, Health, Life Sciences and Physicals Sciences is much higher than other disciplines such as Arts &; Humanities and Social Sciences. Since most of the research output in India is published in local journals, the study suggests further analyses of publications which are not published in Web of Science indexed journals.  相似文献   
109.
Cadaver dissection stands as a crucial component in medical curricula around the world, although computer‐based multimedia programs have been introduced in order to replace the need for cadaver donations. Due to a decrease in the number of unclaimed bodies and rather few donations, there is an insufficient number of cadavers for anatomical studies in Iran. This study was carried out to evaluate medical students' awareness and willingness regarding body donation in Kashan University of Medical Sciences, Iran. In this study, a questionnaire was designed to focus on the cultural acceptability and personal willingness to donate one's body after death. Students from the university's anatomy classes (n = 331) participated in this study. Seventy‐seven percent of the students expressed their agreement toward the idea of utilizing body donation services, though only 25.4% of participants were willing to donate their own bodies. None of the demographic factors were associated with cultural acceptability or personal willingness towards body donation. These findings indicated that besides “payment”, other factors were associated with students' willingness to become donors. All factors of awareness except “previous awareness of organization” were associated with cultural acceptability. In this study, students suggested that encouraging people to register for body donation using mass media (25.6%) and teaching students to respect cadavers in the dissection environment (24.8%) were the best solutions for addressing the lack of cadavers. These findings indicated that a lack of awareness about body donation might be the main factor responsible for unwillingness towards body donation; therefore, improving the public's awareness and addressing the willingness of students regarding body donation may help overcome the current lack of donated cadavers. Anat Sci Educ 10: 120–126. © 2016 American Association of Anatomists.  相似文献   
110.
In recent years, domestic demand for MBAs has fallen in most major Western markets but has increased or remained stable in emerging economies such as China and the United Arab Emirates (UAE), which are the two countries globally that host the largest numbers of international branch campuses. Thus, this research aimed to discover why students in China and the UAE still want an MBA. A survey questionnaire was completed by a total of 354 MBA students, at two universities in China and two universities in the UAE. Some of the results were surprising and unexpected. For example, recognition, prestige and networking – all key features in Chinese and Emirati societies – were found not to be key motivators for wanting an MBA. Instead, the desire to acquire knowledge and skills was the strongest motivator among respondents, accounting for 32.4 per cent of variance. This was followed by reasons associated with intrinsic benefits. The findings have implications for institutional strategy, curriculum design, program delivery and the marketing of programs.  相似文献   
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