Manipulating particle trajectories with phase-control in surface acoustic wave microfluidics     

Orloff ND  Dennis JR  Cecchini M  Schonbrun E  Rocas E  Wang Y  Novotny D  Simmonds RW  Moreland J  Takeuchi I  Booth JC 《Biomicrofluidics》2011,5(4):44107-441079

We present a 91 MHz surface acoustic wave resonator with integrated microfluidics that includes a flow focus, an expansion region, and a binning region in order to manipulate particle trajectories. We demonstrate the ability to change the position of the acoustic nodes by varying the electronic phase of one of the transducers relative to the other in a pseudo-static manner. The measurements were performed at room temperature with 3 μm diameter latex beads dispersed in a water-based solution. We demonstrate the dependence of nodal position on pseudo-static phase and show simultaneous control of 9 bead streams with spatial control of −0.058 μm/deg ± 0.001 μm/deg. As a consequence of changing the position of bead streams perpendicular to their flow direction, we also show that the integrated acoustic-microfluidic device can be used to change the trajectory of a bead stream towards a selected bin with an angular control of 0.008 deg/deg ± 0.000(2) deg/deg.  相似文献   

CONCEPT MAPPING: AN ALTERNATIVE STRATEGY FOR EVALUATION     

Marco Moreira 《Assessment & Evaluation in Higher Education》1985,10(2):159-168

Concept maps are proposed as an alternative tool for evaluation in higher education and examples of concept maps, drawn by college students performing evaluation tasks, are presented in the areas of physics and literature.  相似文献   

Editorial     

Kieran Byrne  Marco Todeschini 《欧洲师范教育杂志》1994,17(1-2):5-7

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Editorial     

Marco Todeschini 《欧洲师范教育杂志》1991,14(3):181-186

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Real and perceived employability: a comparison among Italian graduates     

Luca Caricati  Rita Chiesa  Dina Guglielmi  Marco Giovanni Mariani 《Journal of Higher Education Policy & Management》2016,38(4):490-502

The research undertaken for this article aims to analyse the correspondence between perceived employability and the actual national employment rate among Italian students and graduates undertaking different courses in a large Italian university. Data were collected through a cross-sectional survey of 2087 students in 19 faculties, and compared with the national indicators of employment rate for each faculty. Using faculty as unit of analysis, the results indicated a significant correlation between participants’ perceived employability and national employment rate. This trend was similar for both genders. However, the results showed a difference between bachelor’s and master’s degrees: the correlation between perceived and actual employability was not significant among bachelor’s participants while it remained significant among master’s participants. The results suggest that graduates are only partially aware of their possibility to enter the labour market and this, in turn, highlights that universities have only partially met the goal to increase awareness about the chances of finding a job among students and graduates.  相似文献   

From down house Landlord to Brazilian high school students: What has happened to evolutionary knowledge on the way?     

Nelio Marco Vincenzo Bizzo 《科学教学研究杂志》1994,31(5):537-556

Evolution is considered an essential topic that brings to school a broader perspective of natural phenomena and of the nature of science. Most if not all research has shown that the result of the teaching of evolutionary theories is not positive in different parts of the world. Some have attributed the poor understanding shown by students to teaching style or to students' cognitive abilities. This article reports results of interviews and tests carried out with students after they had been taught the topic of evolution. By adopting a sociocultural perspective, before terming students' views “misconceptions,” attention was given to several different ways Charles Darwin's theories have been re-interpreted by well-known scholars and offered to the public. I have analyzed the approaches taken by Emanuel Radl (1873-1942), John C. Greene, Robert Maxwell Young, and Ernst Mayr to assess the diverse ways Darwinism has been conceived. Attention was also given to the presentation of this controversial knowledge to the public in two major popular books written by respected scientists, Huxley and Kettlewell's Darwin and His World (1975) and Richard Dawkins' more recent The Blind Watchmaker (1989). These analyses revealed remarkable differences between what was written in Downe (Kent) a hundred years ago and what was heard at Sao Paulo (Brazil) nowadays. Students show very poor understanding of evolutionary theories. Their conceptions reveal evolution has been primarily related to the human species. Its meaning is understood as similar to progress, growth, multiplication, and improvement. Biological and cultural evolution are not clearly distinguished. Competition is misunderstood as pure violence, sometimes inevitable, and adaptation is considered an individual process that occurs during the organism's life span. Educational change may not depend just on teaching style and students' cognitive abilities. Modification of factual knowledge and epistemological gaps may be the result of a process of social reconceptualization of knowledge offered to students.  相似文献   

Drawing a spark from darkness: John Walsh and electric fish     

Piccolino M  Bresadola M 《Endeavour》2002,26(1):19-26

John Walsh's research on electric fish, carried out between 1772 and 1775, proved fundamental for demonstrating that electricity might be involved in animal physiology, and, moreover, in favouring a period of great progress in both the physiology and physics of electrical phenomena. However, Walsh is hardly known to modern neuroscientists and is largely neglected by science historians also. One of the reasons for this neglect is that he never published his 'crucial experiment', that is the production of a spark from a discharge of the electric eel.  相似文献   

Guided portfolio writing as a scaffold for reflective learning in in-service contexts: a case study1     

Íris Susana Pires Pereira  Maria Cristina Cristo Parente  Cristina Vieira da Silva 《Teacher Development》2016,20(5):614-630

Language is widely recognized as an inescapable mediating tool for professional learning, and with this text we want to contribute to a better understanding of the particular role that guided writing can play in in-service professional reflective learning. We analysed one pre-school teacher’s written portfolio, the construction of which was guided to scaffold deep thinking about (and the transference of theory into) practice during participation in an in-service program about language education. Our case study shows that the writing process sustained robust learning about professional knowing, doing and learning itself: The teacher elaborated an integrative ethical understanding of the discussed theory, fully experienced newly informed practices and assessed her own learning by using theory to confront her previous knowledge and practices. Throughout the portfolio, the learning stance revealed by her voice varied accordingly. The study illustrates the potential of guided writing to scaffold reflective learning in in-service contexts.  相似文献   

Orphan Works at Theatre Library and Information Centres: Assessing Librarians' Perceptions and Management in Spain     

Silvia Cobo Serrano  Rosario Arquero Avilés  Gonzalo Marco Cuenca  Brenda Siso Calvo 《The Journal of Academic Librarianship》2019,45(1):58-65

Currently, libraries and other information services are facing new professional challenges in relation to digitization policies and orphan works after the publication of European Directive 2012/28/EU on certain permitted uses of orphan works and Spanish Royal Decree 224/2016. This paper aims to analyse how Spanish library and information centres specialising in theatre and performing arts meet users' textual and non-textual information needs, by respecting copyright issues and being involved in a dynamic and digital environment. For this purpose, an online questionnaire, which was used as a methodological tool, was sent to library directors in February 2018. At the same time, some research questions based on orphan works and digitisation approaches are discussed in the paper, specifically in reference to graphic and audiovisual materials.  相似文献   

When is less more? Investigating gap-filling in proofs without words activities     

Marco  Nadav  Palatnik  Alik  Schwarz  Baruch B. 《Educational Studies in Mathematics》2022,110(2):271-290

Educational Studies in Mathematics - Visuospatial representations of numbers and their relationships are widely used in mathematics education. These include drawn images, models constructed with...  相似文献