排序方式： 共有87条查询结果，搜索用时 15 毫秒
41.
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
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This study explored the relationship between school achievement levels and teachers’ expectations, locus of control and efficacy
in four elementary schools in Delta, Mississippi in keeping with the self-fulfilling prophecy theory. Data from surveys of
102 teachers, five focus groups, observations, and secondary information on teachers’ grading pattern were used. Analyses
using t-tests and multiple linear regressions revealed that teachers in high achieving schools tended to exhibit an internal locus
of control and base their expectancies on students’ abilities rather than personal characteristics. School achievement level
was found to be the only significant predictor indicating that high achieving schools had a culture of higher expectations
that affected teachers’ perceptions, motivations, and grading pattern. These findings are substantiated by qualitative assessments. 相似文献
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With a focus on the Hindi language superhero comics produced by Raj Comics since the 1980s, this article investigates instances of “modernities in the backyard” and their implications for studying postcolonial popular culture. The graphic narratives in the comic books are neither simply Westernized or transgressive, nor necessarily framed by a mythicized or Orientalised discursive framework. Instead, they register a distinctive heritage combining vernacular and mythic prototypes with hypermodern visions with which to imagine new powers for Indian men and women, even though women may continue to be shaped by the masculinist, desirous gaze and modulated by patriarchal expectations to do with female docility and marriageability. The enquiry provides unique material to chart out the lineaments of postcolonial culture, gender, and power in order to provincialize the scope of cultural studies. 相似文献
45.
Tony Harland Raja Maznah Raja Hussain Aishah Abu Bakar 《Teaching in Higher Education》2013,18(1):38-48
This paper explores the adoption of the scholarship of teaching and learning (SoTL) by 10 Malaysian university academics. SoTL was part of a pioneering sector-wide initiative for improving teaching and learning. The qualitative study showed that there had been no true learning phase for SoTL because academics had high expectations of rapid success in their new research area, including journal publication. Most of their peers did not understand or value SoTL and so SoTL researchers established minority self-sustaining groups across disciplines and universities. SoTL brought new ways of thinking about teaching that were transformational for the teacher but not necessarily welcomed by the students. Students resisted radical change, and teachers were drawn back to educational practices they no longer valued. SoTL was experienced in a hierarchical educational culture where questioning of self and others was difficult and this hindered teacher development. We conclude with recommendations about realistic expectations and the importance of social learning for those considering SoTL for academic development. 相似文献
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This study illustrates design optimization for multiple wind towers located at different villages in Alaska. The towers are supported by two different types of foundations: large mat or deep piles foundations. Initially, a reinforced concrete (RC) mat foundation was proposed. Where soil conditions required it, a pile foundation solution was devised utilizing a 30 in thick RC mat containing an embedded steel grillage of W18 beams and supported by 20-24 in grouted or un-grouted piles. For faster installation and lower construction cost, all-steel foundations were proposed for these remote Alaska sites. The new all-steel design was found to reduce the natural frequencies of the structural system due to softening the foundation. Thus, the tower-foundation system could potentially become near-resonant with the operational frequencies of the wind turbine. Consequently, the likelihood of structural damage or even the collapse is increased.A detailed 3D finite-element model of the tower-foundation-pile system with RC foundation was created using SAP2000. Soil springs were included in the model based on soil properties obtained from the geotechnical investigation. The natural frequency from the model was verified against the tower manufacturer analytical and experimental values. When piles were used, numerous iterations were carried out to eliminate the need for the RC and optimize the design. An optimized design was achieved with enough separation between the natural and operational frequencies. The design successfully avoids damage to the structural system, while eliminating the need for any RC in most cases. 相似文献
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In this paper, we demonstrate biphasic microfluidic droplets with broadly tunable internal structures, from simple near-equilibrium drop-in-drop morphologies to complex yet uniform non-equilibrium steady-state structures. The droplets contain an aqueous mixture of poly(ethylene glycol) (PEG) and dextran and are dispensed into an immiscible oil in a microfluidic T-junction device. Above a certain well-defined threshold droplet speed, the inner dextran-rich phase is "stirred" within the outer PEG-rich phase. The stirred polymer mixture is observed to exhibit a near continuum of speed and composition-dependent phase morphologies. There is increasing interest in the use of such aqueous two-phase systems in microfluidic devices for biomolecular applications in a variety of contexts. Our work presents a method to go beyond equilibrium phase morphologies in generating microfluidic "multiple" emulsions and at the same time raises the possibility of biochemical experimentation in benign yet complex biomimetic milieus. 相似文献
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Khan SA 《Biomicrofluidics》2012,6(2):21901-219012
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A full order fractional-order observer is designed for a class of Lipschitz continuous-time nonlinear fractional-order systems with unknown input. Sufficient conditions of existence for the designed observer and stability of state estimation error system are developed by reconstructing state and using general quadratic Lyapunov function. By applying fractional-order extension of Lyapunov direct method, the stability of the fractional-order state estimation error system is analyzed. Due to the conditions involving a nonlinear matrix inequality, a new sufficient condition with linear matrix inequality (LMI) is reformulated, which makes the full order fractional-order observer implemented easily by using Matlab LMI toolbox. Examples are taken to show the effectiveness of the proposed approach by numerical simulations. 相似文献