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31.
Integration of microfluidic devices with pressure-driven, self-powered fluid flow propulsion methods has provided a very effective solution for on-chip, droplet blood testing applications. However, precise understanding of the physical process governing fluid dynamics in polydimethylsiloxane (PDMS)-based microfluidic devices remains unclear. Here, we propose a pressure-driven diffusion model using Fick''s law and the ideal gas law, the results of which agree well with the experimental fluid dynamics observed in our vacuum pocket-assisted, self-powered microfluidic devices. Notably, this model enables us to precisely tune the flow rate by adjusting two geometrical parameters of the vacuum pocket. By linking the self-powered fluid flow propulsion method to the sedimentation, we also show that direct plasma separation from a drop of whole blood can be achieved using only a simple construction without the need for external power sources, connectors, or a complex operational procedure. Finally, the potential of the vacuum pocket, along with a removable vacuum battery to be integrated with non-PDMS microfluidic devices to drive and control the fluid flow, is demonstrated. 相似文献
32.
In this paper, we introduce a novel knowledge-based word-sense disambiguation (WSD) system. In particular, the main goal of our research is to find an effective way to filter out unnecessary information by using word similarity. For this, we adopt two methods in our WSD system. First, we propose a novel encoding method for word vector representation by considering the graphical semantic relationships from the lexical knowledge bases, and the word vector representation is utilized to determine the word similarity in our WSD system. Second, we present an effective method for extracting the contextual words from a text for analyzing an ambiguous word based on word similarity. The results demonstrate that the suggested methods significantly enhance the baseline WSD performance in all corpora. In particular, the performance on nouns is similar to those of the state-of-the-art knowledge-based WSD models, and the performance on verbs surpasses that of the existing knowledge-based WSD models. 相似文献
33.
Crawford April Vaughn Kelly A. Guttentag Cathy L. Varghese Cheryl Oh Yoonkyung Zucker Tricia A. 《Early Childhood Education Journal》2021,49(5):829-840
Early Childhood Education Journal - The COVID-19 pandemic impacted early childhood programs serving infants, toddlers, and preschoolers in dramatic ways. After temporarily closing, many educators... 相似文献
34.
Lohmann Marla J. Randolph Kathleen M. Oh Ji Hyun 《Early Childhood Education Journal》2021,49(5):807-814
Early Childhood Education Journal - The COVID-19 pandemic changed the way that schools provide instruction to learners and these changes may last for an extended period of time. One current trend... 相似文献
35.
In Experiment 1, rats were trained to leverpress on a variable ratio (VR) 30 schedule with a 500-msec delay between the reinforced response and food delivery. Subjects that experienced a signal during the delay responded faster than did control subjects that received the stimulus un-correlated with reinforcement. Higher response rates were obtained when the stimulus used to signal reinforcement was auditory rather than visual. Experiments 2 and 3 compared the effects of signaling reinforcement with either a localized or a diffuse light on responding maintained by VR schedules of reinforcement. Elevated response rates were observed with the diffuse stimulus, but the localized stimulus failed to produce such potentiation. Experiment 3 also examined the conditioned reinforcing power of localized and diffuse visual stimuli. These results are discussed with reference to (1) theories of selective association and sign tracking and (2) their implications for current theories of signaling reinforcement. 相似文献
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Quantum chemistry is based on the solution of the Schrödinger equation for a molecule. From starting data on the positions and nature of constituent atoms information is provided about the energy of the molecule and its electronic properties. The former can indicate what shapes drugs can adopt in binding to pharmacological receptors whilst electronic details, when compared using computer graphics, may highlight the factors responsible for biological activity. These techniques are beginning to show real successes in the design of drug molecules. 相似文献
38.
Cataglyphis is an ant of desert regions and has a behavioural pattern comparable with that of the bee, but much easier to study. It has a well-developed system of foraging and navigating and a social organisation well adapted to its environment. This review, by two independent research workers who have devoted much time to field studies, is the first to bring together most of the existing information about these fascinating insects. 相似文献
39.
Brendan O’Connell Paul De Lange Mark Freeman Phil Hancock Anne Abraham Bryan Howieson 《Assessment & Evaluation in Higher Education》2016,41(3):331-349
Reliable, consistent assessment process that produces comparable assessment grades between assessors and institutions is a core activity and an ongoing challenge with which universities have failed to come to terms. In this paper, we report results from an experiment that tests the impact of an intervention designed to reduce grader variability and develop a shared understanding of national threshold learning standards by a cohort of reviewers. The intervention involved consensus moderation of samples of accounting students’ work, with a focus on three research questions. First, what is the quantifiable difference in grader variability on the assessment of learning outcomes in ‘application skills’ and ‘judgement’? Second, does participation in the workshops lead to reduced disparity in the assessment of the students’ learning outcomes in ‘application skills’ and ‘judgement’? Third, does participation in the workshops lead to greater confidence by reviewers in their ability to assess students’ skills in application skills and judgement? Our findings suggest consensus moderation does reduce variability across graders and also builds grader confidence. 相似文献
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