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51.
Abdul Waheed Mughal Jo Aldridge 《Educational Studies A Journal of the American Educational Studies Association》2017,53(4):359-376
This study investigates head teachers' perspectives of the school dropout problem at public secondary schools in rural Punjab, Pakistan. The study is based on qualitative methods and included interviews to collect primary data. Sixteen districts of the Punjab where secondary school dropout rate is above 20% were purposively selected for the study. The findings indicate that—other than some socioeconomic and individual factors—different exam patterns at primary, elementary, and secondary levels; easy promotion policy in early classes; English medium syllabus; substandard educational background of students; high failure rate in class 9; and top-down pressures on teachers to perform nonacademic duties are major causes of children dropping out from school. The findings of the study suggest that only through implementation of a socio-culturally compatible syllabus—a corresponding examination system for all levels—allowing students to repeat class 9 in case they fail, setting teachers free from nonteaching duties and providing extra financial support to economically underprivileged students can significantly prevent school dropout at secondary level. The study further argues that easy promotion policy in early classes may retain more children at school but it causes high rates of dropout from secondary classes. 相似文献
52.
Student attrition and academic and social integration: Application of Tinto’s model at the University of Papua New Guinea 总被引:1,自引:0,他引:1
Md. Abdul Mannan 《Higher Education》2007,53(2):147-165
This study explores the compensatory relationship between academic and social integration, and also assesses the differences
of group specific academic and social integration in a small university in the Pacific as perceived by the students. In order
to reduce attrition through developing a relevant retention policy, a comprehensive group specific assessment of academic
and social integration was necessary. Using the Tinto model and research instruments, an institutional academic and social
integration assessment instrument was developed for measuring perceived integration climate for specific subject and year
of studies groups. An important outcome of this study was the existence of a compensatory relationship between academic and
social integration. Differences were found between perceived ratings of student groups for both academic and social integration. 相似文献
53.
Abdul Latif Khan Syed Abdullah Gilani Muhammad Waqas Khadija Al-Hosni Salima Al-Khiziri Yoon-Ha Kim Liaqat Ali Sang-Mo Kang Sajjad Asaf Raheem Shahzad Javid Hussain In-Jung Lee Ahmed Al-Harrasi 《Journal of Zhejiang University. Science. B》2017,18(2):125-137
Medicinal plants have been used by marginal communities to treat various ailments. However, the potential of endophytes within these bio-prospective medicinal plants remains unknown. The present study elucidates the endophytic diversity of medicinal plants (Caralluma acutangula, Rhazya stricta, and Moringa peregrina) and the endophyte role in seed growth and oxidative stress. Various organs of medicinal plants yielded ten endophytes, which were identified as Phoma sp. (6 isolates), Alternaria sp. (2), Bipolaris sp. (1), and Cladosporium sp. (1) based on 18S rDNA sequencing and phylogenetic analysis. The culture filtrates (CFs; 25%, 50%, and 100% concentrations) from these endophytes were tested against the growth of normal and dwarf mutant rice lines. Endophytic CF exhibited dose-dependent growth stimulation and suppression effects. CF (100%) of Phoma sp. significantly increased rice seed germination and growth compared to controls and other endophytes. This growth-promoting effect was due to the presence of indole acetic acid in endophytic CF. The gas chromatography/mass spectrometry (GC/MS) analysis showed the highest indole acetic acid content ((54.31±0.21) μmol/L) in Bipolaris sp. In addition, the isolate of Bipolaris sp. exhibited significantly higher radical scavenging and anti-lipid peroxidation activity than the other isolates. Bipolaris sp. and Phoma sp. also exhibited significantly higher flavonoid and phenolic contents. The medicinal plants exhibited the presence of bio-prospective endophytic strains, which could be used for the improvement of crop growth and the mitigation of oxidative stresses. 相似文献
54.
Zhi Chao Ong Hong Cheet Lim Shin Yee Khoo Zubaidah Ismail Keen Kuan Kong Abdul Ghaffar Abdul Rahman 《浙江大学学报(A卷英文版)》2017,18(2):92-105
The impact-synchronous modal analysis (ISMA), which uses impact-synchronous time averaging (ISTA), allows modal testing to be performed during operation. ISTA is effective in filtering out the non-synchronous cyclic load component, its harmonics, and noises. However, it was found that at operating speeds that coincide with the natural modes, ISMA would require a high number of impacts to determine the dynamic characteristics of the system. This finding has subsequently reduced the effectiveness and practicality of ISMA. Preservation of signatures during ISTA depends on the consistency of their phase angles on every time block but not necessarily on their frequencies. Thus, the effect of phase angles with respect to impact is seen to be a very important parameter when performing ISMA on structures with dominant periodic responses due to cyclic load and ambient excitation. The responses from unaccounted forces that contain even the same frequency as that contained in the response due to impact are diminished with the least number of impacts when the phase of the periodic responses is not consistent with the impact signature for every impact applied. The assessment showed that a small number of averages are sufficient to eliminate the non-synchronous components with 98.48% improvement on simulation and 95.22% improvement on experimental modal testing when the phase angles with respect to impact are not consistent for every impact applied. 相似文献
55.
56.
Kim-seng Chia Herlina Abdul Rahim Ruzairi Abdul Rahim 《Journal of Zhejiang University. Science. B》2012,13(2):145-151
Visible and near infrared spectroscopy is a non-destructive, green, and rapid technology that can be utilized to estimate
the components of interest without conditioning it, as compared with classical analytical methods. The objective of this paper
is to compare the performance of artificial neural network (ANN) (a nonlinear model) and principal component regression (PCR)
(a linear model) based on visible and shortwave near infrared (VIS-SWNIR) (400–1000 nm) spectra in the non-destructive soluble
solids content measurement of an apple. First, we used multiplicative scattering correction to pre-process the spectral data.
Second, PCR was applied to estimate the optimal number of input variables. Third, the input variables with an optimal amount
were used as the inputs of both multiple linear regression and ANN models. The initial weights and the number of hidden neurons
were adjusted to optimize the performance of ANN. Findings suggest that the predictive performance of ANN with two hidden
neurons outperforms that of PCR. 相似文献
57.
Chiong Ing Tiong Yahya Azli Mohammed Rafiq Abdul Kadir Samion Syahrullail 《浙江大学学报(A卷英文版)》2012,13(8):633-640
The effects of the mechanical factors with applied loads on the tribological performance of refined, bleached and deodorised (RBD) palm stearin (PS) were studied using a four-ball tribotester. All the RBD PS results were simultaneously compared with the additive-free paraffinic mineral oil (PMO). The experiments were carried out using different loads with a constant speed in order to gain a better understanding of the mechanical processes that occurred during the experiment. For each experiment, the temperature was increased to 75 °C and was run for 1 h. In a mechanical system, lubricant plays an important role in reducing wear and friction. PS exists as a semi-solid at room temperature after the fractionation process from oil palm. Due to the increasing rate of pollution to the environment, vegetable oil was chosen as the test lubricant with regard to its biodegradability. Other advantages of vegetable oil are that it is more easily harvestable and non-toxic compared to petroleum-based oil, which made it a suitable candidate. From the experiment, RBD PS is found to have a better friction constraint reduction compared with additive-free PMO. 相似文献
58.
Rao AQ Hussain SS Shahzad MS Bokhari SY Raza MH Rakha A Majeed A Shahid AA Saleem Z Husnain T Riazuddin S 《Journal of Zhejiang University. Science. B》2006,7(4):291-298
Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction media were tested with varying concentrations of hormones in which sucrose was used as nutritional source. Different explants (hypocotyls, cotyledon, root) were used to check the regeneration of both local cotton plants and wild relatives using T & G medium, BAP medium, CIM medium, EMMS medium, and cell suspension medium. Different stages of embryogenicity such as early torpedo stage, late torpedo stage, heart stage, globular stage and cotyledonary stage were observed in wild relatives of cotton. The results of this study pave the way for establishing future transformation methods. 相似文献
59.
60.
There is widespread belief that exposure to television has harmful effects on children's cognitive development. Most studies that point to a negative correlation between hours of television watching and cognitive outcomes, fail to establish causality. Using the National Longitudinal Survey of Youth (NLSY) we study young children between 5 and 10 years of age during late 1990s and early 2000s. We find strong evidence of negative correlations between hours of television watched and cognitive test scores. However, once parent's characteristics and unobserved child characteristics are taken into account these correlations go away. We find that hours of television viewed per se do not have any measurable impact on children's test scores. Our results are robust to different model specifications and instrumental variable estimates. We conclude that despite the conventional wisdom and the ongoing populist movement, proactive policies to reduce children's television exposure are not likely to improve children's cognitive development and academic performance. 相似文献