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11.
This paper reports research on the effects of variations in injection velocity and permeability on the heat transfer and flow
through a highly porous medium between two horizontal parallel plates situated at constant distance with constant suction
by the upper plate. Due to this type of variation in injection velocity and in permeability the flow becomes three dimensional.
The governing equations are solved by adopting complex variable notations to obtain the expressions for the velocity and temperature
field. The skin-friction along the main flow direction and rate of heat transfer are discussed with the help of graphs. 相似文献
12.
This meta-analysis integrates 296 effect sizes reported in eye-tracking research on expertise differences in the comprehension
of visualizations. Three theories were evaluated: Ericsson and Kintsch’s (Psychol Rev 102:211–245, 1995) theory of long-term working memory, Haider and Frensch’s (J Exp Psychol Learn Mem Cognit 25:172–190, 1999) information-reduction hypothesis, and the holistic model of image perception of Kundel et al. (Radiology 242:396–402, 2007). Eye movement and performance data were cumulated from 819 experts, 187 intermediates, and 893 novices. In support of the
evaluated theories, experts, when compared with non-experts, had shorter fixation durations, more fixations on task-relevant
areas, and fewer fixations on task-redundant areas; experts also had longer saccades and shorter times to first fixate relevant
information, owing to superiority in parafoveal processing and selective attention allocation. Eye movements, reaction time,
and performance accuracy were moderated by characteristics of visualization (dynamics, realism, dimensionality, modality,
and text annotation), task (complexity, time-on-task, and task control), and domain (sports, medicine, transportation, other).
These findings are discussed in terms of their implications for theories of visual expertise in professional domains and their
significance for the design of learning environments. 相似文献
13.
Learners studying mechanical or technical processes via dynamic visualizations often fail to build an accurate mental representation
of the system’s movements. Based on embodied theories of cognition assuming that action, perception, and cognition are closely
intertwined, this paper proposes that the learning effectiveness of dynamic visualizations could be enhanced by grounding
the movements of the presentation in people’s own bodily experiences during learning. We discuss recent research on embodied
cognition and provide specific strategies for how the body can be used to ground movements during the learning process: (1)
making or observing gestures, (2) manipulating and interacting with objects, (3) using body metaphors, and (4) using eye movements
as retrieval cues. Implications for the design of dynamic visualizations as well as directions for future research are presented. 相似文献
14.
15.
Formal models for service composition have been proposed with the variation of the requirements of service developers. Some
famous models have provided checking and verification techniques and tools for the behavior of service composition. These
models generally focus much on the message flow of web services and neglecting the data contained in the exchanged messages
among services, which restrict the application range of these models and also the web service techniques. As new kind of services
with different protocols and communication methods have appeared, it is needed to model service composition from a new view
which is adapted to the new development in service area. In this paper we offer a function oriented model of service composition
which treats the composite service as a software system and specify the function of services which can be directly used to
the realization by service providers. 相似文献
16.
The author articulates key stressors in the lives of families who are homeless. These stresses often combine with barriers such as lack of job opportunities and/or insensitive professionals. Strategies for helping homeless families overcome these barriers and related issues are presented. 相似文献
17.
18.
Yangxueqingnao particles inhibit rat vascular smooth muscle cell proliferation induced by lysophosphatidic acid 总被引:1,自引:0,他引:1
Cai W Xu Y Chen JZ Huang SR Lu ZY Wang ZK 《Journal of Zhejiang University. Science. B》2005,6(9):892-896
Objective: To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) proliferation induced by lysophosphatidic acid (LPA). Methods: The amount of3H-TdR (3H-thymidine) admixed in cultured rat VSMC was measured and mitogen-activated protein kinase (MAPK) activity and lipid peroxidation end product malondialdehyde (MDA)content of the VSMC were assayed. Results: 1×10-9, 1×10-8, 1×10-7 mol/L LPA in a concentration dependent manner, induced the amount of 3H-TdR admixed, MAP kinase activity, and MDA content of the cultured rat VSMC to increase. However, 5%, 10%,and 15% Yangxueqingnao serum preincubation resulted in a decrease of 23.0%, 42.0%, and 52.0% (P<0.01) respectively in the amount of 3H-TdR admixed, a decline in VSMC MAP kinase activity of 13.9% (P<0.05), 29.6% (P<0.01), and 48.9% (P<0.01)respectively, and also, a decrease in MDA content of VSMC of 19.4%, 24.7%, and 43.2% (P<0.01) respectively, in the 1×10-7mol/L LPA-treated VSMC. Conclusions: LPA activates the proliferation and lipid peroxidation of VSMC in a concentration dependent manner. The LPA-induced VSMC proliferation is related to the activity of MAP kinases, enzymes involved in an intracellular signalling pathway. The results of the present study showed that Yangxueqingnao particles can effectively inhibit LPA-induced VSMC proliferation, MAP kinase activation, and reduce lipid peroxidative lesion. 相似文献
19.
This investigation analyzed goals from the Individual Educational Programs (IEPs) of 54 high school students with diagnosed
reading disabilities in basic skills (decoding and/or word identification). Results showed that for 73% of the students, the
IEPs written when they were in high school failed to specify any objectives regarding their acute difficulties with basic
skills. IEPs from earlier points in the students’ educations were also reviewed, as available. For 23 of the students, IEPs
were present in the students’ files for three time points: elementary school (ES), middle school (MS), and high school (HS).
Another 20 students from the sample of 54 had IEPs available for two time points (HS and either MS or ES). Comparisons with
the IEPs from younger years showed a pattern of decline from ES to MS to HS in the percentage of IEPs that commented on or
set goals pertaining to weaknesses in decoding. These findings suggest that basic skills deficits that persist into the upper
grade levels are not being sufficiently targeted for remediation, and help explain why older students frequently fail to resolve
their reading problems. 相似文献
20.
Objective: To investigate the effect of interleukin-18 (IL-18) on immune response induced by plasmid encoding hepatitis B virus middle protein antigen and to explore new strategies for prophylactic and therapeutic HBV DNA vaccines. Methods: BALB/c mice were immunized with pCMV-M alone or co-immunized with pcDNA3-18 and pCMV-M and then their sera were collected for analysing anti-HBsAg antibody by ELISA; splenocytes were isolated for detecting specific CTL response and cytokine assay in vitro. Results: The anti-HBs antibody level of mice co-immunized with pcDNA3-18 and pCMV-M was slightly higher than that of mice immunized with pCMV-M alone, but there was not significantly different (P>0.05). Compared with mice injected with pCMV-M, the specific CTL cytotoxity activity of mice immunized with pcDNA3-18 and pCMV-M was significantly enhanced (P<0.05) and the level of IFN-γ in supernatant of splenocytes cultured with HBsAg in vitro was significantly elevated (P<0.05) while the level of IL-4 had no significant difference (P>0.05). Conclusion: The plasmid encoding IL-18 together with HBV M gene DNA vaccines may enhance specific TH1 cells and CTL cellular immune response induced in mice, so that IL-18 is a promising immune adjuvant. 相似文献