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排序方式: 共有1351条查询结果,搜索用时 31 毫秒
1.
Duparc Estelle Möller Frederik Jussen Ilka Stachon Maleen Algac Sükran Otto Boris 《Electronic Markets》2022,32(2):727-745
Electronic Markets - The open-source paradigm offers a plethora of opportunities for innovative business models (BMs) as the underlying codebase of the technology is accessible and extendable by... 相似文献
2.
Kai Sun Wei Xiao Sheng Ye Nikolaos Kalfagiannis Kian Shen Kiang C. H. de Groot Otto L. Muskens 《Advanced materials (Deerfield Beach, Fla.)》2020,32(25):2001534
New methods for achieving high-quality conducting oxide metasurfaces are of great importance for a range of emerging applications from infrared thermal control coatings to epsilon-near-zero nonlinear optics. This work demonstrates the viability of plasma patterning as a technique to selectively and locally modulate the carrier density in planar Al-doped ZnO (AZO) metasurfaces without any associated topographical surface profile. This technique stands in strong contrast to conventional physical patterning which results in nonplanar textured surfaces. The approach can open up a new route to form novel photonic devices with planar metasurfaces, for example, antireflective coatings and multi-layer devices. To demonstrate the performance of the carrier-modulated AZO metasurfaces, two types of devices are realized using the demonstrated plasma patterning. A metasurface optical solar reflector is shown to produce infrared emissivity equivalent to a conventional etched design. Second, a multiband metasurface is achieved by integrating a Au visible-range metasurface on top of the planar AZO infrared metasurface. Independent control of spectral bands without significant cross-talk between infrared and visible functionalities is achieved. Local carrier tuning of conducting oxide films offers a conceptually new approach for oxide-based photonics and nanoelectronics and opens up new routes for integrated planar metasurfaces in optical technology. 相似文献
3.
Margot Otto Beulah Pretorius Quenton Kritzinger Hettie Schönfeldt 《Journal of Food Safety》2020,40(6):e12846
Freshly harvested Bambara groundnut (BGN) is occasionally consumed raw and can potentially become infected with mycotoxingenic field fungi. In this study, BGN samples were obtained from 12 farms in three districts of Mpumalanga in South Africa. Eight pooled samples were screened for multi-mycotoxin contamination using Ultra Performance Liquid-Chromatography tandem mass spectrometry (UPLC-MS/MS). To identify mycoflora, 12 samples were screened using conventional and molecular methods. Selected potential mycotoxin producing isolates were screened for mycotoxins using UPLC-MS/MS. No mycotoxins were detected on the freshly harvested BGN samples, but they were infected with various mycotoxin producing fungal species namely Aspergillus flavus (50%), Penicillium citrinum (25%), Penicillium oxalicum (17%), Penicillium citreoviridin (0.8%), and Fusarium verticillioides (0.8%). Following screening of selected fungal cultures, aflatoxin B1 (0.4, 0.45 and 0.4 ppm) and fumonisin B1 (0.7 ppm) were detected from A. flavus and F. verticillioides, respectively. Identification of mycotoxigenic fungi on freshly harvested BGN presents a potential health risk. 相似文献
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Characklis GW Dilts MJ Simmons OD Likirdopulos CA Krometis LA Sobsey MD 《Water research》2005,39(9):1773-1782
The degree to which microbes in the water column associate with settleable particles has important implications for microbial transport in receiving waters, as well as for microbial removal via sedimentation (i.e. detention basins). The partitioning behavior of several bacterial, protozoan and viral indicator organisms is explored in three urban streams under both storm and dry weather conditions. The fraction of organisms associated with settleable particles in stormwater is estimated through use of a centrifugation technique which is calibrated using suspensions of standard particles (e.g., glass, latex). The fraction of organisms associated with settleable particles varies by type of microbe, and the partitioning behavior of each organism generally changes between dry weather and storm conditions. Bacterial indicator organisms (fecal coliforms, Escherichia coli, enterococci) exhibited relatively consistent behavior, with an average of 20-35% of organisms associated with these particles in background samples and 30-55% in storm samples. Clostridium perfringens spores exhibited the highest average level of particle association, with storm values varying from 50% to 70%. Results related to total coliphage partitioning were more variable, with 20-60% associated with particles during storms. These estimates should be valuable in surface water quality modeling efforts, many of which currently assume that all microbes exist as free (unattached) organisms. 相似文献
7.
In many countries a large part of the building stock will have to be maintained, renovated, rehabilitated or even removed in the next few decades. Although profitability will be one of the major requirements to be met when these works are carried out, there will be more and more emphasis on the environmental requirements to be respected. To make the modernization of the building stock more efficient, dismantling with the aim of producing high quality recycling materials at reasonable costs is a promising approach. This paper presents an integrated approach to deconstruction site management that focuses on both economic and environmental goals. As a first step, material flow management aims at the closed-loop recycling of various construction materials. In a second step, resource constrained project planning models are used to evaluate strategies for optimized deconstruction site management. The approach offers high flexibility and can be adapted readily to different conditions. Results show that time and cost for deconstruction can be reduced by more than 50%, together with recycling quotas of more than 90%. Even when resources are strictly limited or when strong budget and time restrictions have to be respected, tremendous improvements in deconstruction site management can be achieved. 相似文献
8.
Effect of Constant‐Rate Reduction on the Performance of a Ternary Cu/ZnO/Al2O3 Catalyst in Methanol Synthesis 下载免费PDF全文
A multi‐functional flow set‐up was developed for the rate‐ and temperature‐controlled reduction of copper catalysts, their application in high‐pressure methanol synthesis and the determination of the copper surface area by N2O frontal chromatography. The influence of constant‐rate reduction on the catalytic properties of a ternary Cu/ZnO/Al2O3 catalyst was investigated. The temperature during the constant‐rate reduction was found to decrease, indicating autocatalytic kinetics, but no significant catalytic effect of the milder reduction conditions was observed compared with a slow linear heating ramp. 相似文献
9.
Chongxin Yuan N.Bert Roozen Otto Bergsma Adriaan Beukers 《Engineering Analysis with Boundary Elements》2013,37(2):250-259
The aircraft fuselage is idealized as a composite cylinder, its vibroacoustic properties are studied both experimentally and numerically, and a minimization of the inner pressure of a composite cylinder is conducted with the genetic algorithm (GA). In the optimization, the Acoustic Transfer Vector (ATV), which comes from the boundary element method, builds the relationship between the structural surface velocity and the sound pressure at the specific filed points. Results show that the noise reduction obtained by the experimental and numerical methods have a good agreement; the optimization method which combines GA and ATV show high efficiency and robustness; increase of the bending stiffness of the cylinder can improve the noise reduction at low frequencies; both the reduction of weight and the increase of noise insulation can be achieved by the optimization of the layup at different regions of the cylinder individually. 相似文献
10.
Günther Huber Otto Machhammer Maren Lepple Claudia Weidlich Cord-Henrich Dustmann Akane Hartenbach 《化学,工程师,技术》2021,93(4):664-672
A photovoltaic system could supply a single-family house with electrical power, warm water, and room heat if the energy would be distributed over the year to suit the load profile. However, storage systems for this are not state of the art yet. A concrete example is used to estimate which parameters such a power storage system should have. A suitable electrochemical reaction system based on inorganic salt mixtures is proposed. The German Federal Ministry of Education and Research is currently funding the development of a world storage facility based on the same reaction system. 相似文献