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排序方式: 共有407条查询结果,搜索用时 15 毫秒
81.
Chiou Sheng Chew Norisma Idris Er Fu Loh Wen‐Chi Vivian Wu Yan Piaw Chua Andrew Thomas Bimba 《Journal of Computer Assisted Learning》2019,35(3):435-449
This paper focuses on the design and evaluation of a theory‐based computer‐assisted summary writing learning environment called Summary Writing‐PAL (SW‐PAL). The SW‐PAL was developed based on four aspects: summarizing strategies, learning theories, prior knowledge, and cognitive load. A quasi‐experiment that involved 58 undergraduates majoring in Computer Science was conducted to examine the effectiveness of SW‐PAL in writing summaries. Two intact classes were selected with 28 and 30 students in control and experimental groups, respectively. The conventional teaching approach was employed in the control group, whereas the SW‐PAL was introduced to the experimental group. Pretest and posttest were administrated to both groups. The findings indicated that SW‐PAL improved students' summary writing performance. A significant variance was noted between intrinsic and extraneous cognitive load among students with varying levels of English proficiency in the experimental group, signifying that the SW‐PAL is more suitable for students with lower language proficiency. 相似文献
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84.
C M Vivian 《The Science of the total environment》1986,53(1-2):5-40
A review of the available and potential tracers of the movement and distribution of sewage sludge ('sludge') in and on marine sediments is presented. A brief review of 'active' sludge tracers is followed by a more extensive review of 'passive' sludge tracers. These can be broken down into five categories: Natural organic components of sludge--organic carbon, faecal steroids, carbohydrate/TOC ratio, tomato seeds. Synthetic organic compounds--silicones, chlorinated hydrocarbons, non-ionic surfactants and their degradation products, linear alkylbenzenes. Stable isotopes of carbon, nitrogen, hydrogen and sulphur. Inorganic substances and their properties--minerals, paint pigments, trace elements, magnetic properties. Biological/Microbiological--faecal bacteria, Clostridium welchii spores, amoebae, viruses, nitrogen-fixing enterobacteriaceae. A wide variety of sludge tracers are available with the choice of suitable tracers in an individual situation governed by the available equipment and expertise, cost considerations, ease of sampling requirements and determination, and the nature of other pollutant inputs in the vicinity of the input of interest. Ideally, the sludge tracers chosen should be unique to the input of interest, but this will rarely be achievable in practice. In areas of gross sludge contamination, a marine geophysical survey technique can be used to delineate the area affected and this provides a rapid cost-effective method for large areas. 相似文献
85.
Optimized spatial correlations for broadband light trapping nanopatterns in high efficiency ultrathin film a-Si:H solar cells 总被引:1,自引:0,他引:1
Nanophotonic structures have attracted attention for light trapping in solar cells with the potential to manage and direct light absorption on the nanoscale. While both randomly textured and nanophotonic structures have been investigated, the relationship between photocurrent and the spatial correlations of random or designed surfaces has been unclear. Here we systematically design pseudorandom arrays of nanostructures based on their power spectral density, and correlate the spatial frequencies with measured and simulated photocurrent. The integrated cell design consists of a patterned plasmonic back reflector and a nanostructured semiconductor top interface, which gives broadband and isotropic photocurrent enhancement. 相似文献
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The effects of microfluidisation of milk at different pressures, prior to heat treatment, on structural and sensory properties of low-fat stirred yoghurt, were investigated. Low-fat yoghurts prepared from microfluidised milk were compared with low-fat (1.5%) and full-fat (3.5%) control yoghurts made with homogenised (20/5 MPa) milk. The microstructure of low-fat yoghurts prepared with microfluidised milk consisted of smaller and more uniform fat globules, well incorporated into more interconnected fat-protein gel networks, compared with those of control yoghurts. This modification in microstructure caused significant changes in gel particle size, sensory profile and rheological behaviour. Microfluidisation increased the gel particle size, gel strength and viscosity; marked beneficial effects were found at higher pressures (50–150 MPa). Microfluidising milk at 50–150 MPa increased the gel strength by 171–195% and viscosity by 98–103%, creating low-fat yoghurts with creaminess and desirable texture properties similar to, or better than, full-fat conventional yoghurt. 相似文献
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Torsten Henning Juergen J. Brandner Lutz Eichhorn Klaus Schubert Martin Schreiber Martin Güngerich Hermann Günther Peter J. Klar Vivian Rebbin Michael Fröba 《Microfluidics and nanofluidics》2007,3(3):299-305
We have incorporated microspheres, from 50 to 80 μm in diameter, of periodic mesoporous organosilica (inner surfaces up to
1,000 m2/g and pore sizes in the nanometre range) with two types of organic functionalities (benzene and ethane bridges, respectively)
inside microstructured channels (each 200 μm wide and 100 μm deep) and, exemplarily, monitored by Raman microscopy (Raman
spectroscopy through microscope optics) that the temperature characteristics of the adsorption–desorption equilibria of benzene
and ethanol vary significantly with the type of organic functionality of the microspheres and the pore morphology. The integration
of this class of nanostructured material into devices by means of microchannels is a promising novel approach to, among others,
substance separation in analytics, micro process engineering, and micro chemistry. 相似文献