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71.
The use of fluorescent probes for the appraisal of microviscosity properties of cell membranes, both inside the lipid double layer and/or near the double layer surface, are today an usual tool in cell biology. In the present paper an attempt was made to establish if there are significant changes in the mechanical properties of the host cell membranes. 相似文献
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R Starmans JW Muris GH Fijten HJ Schouten P Pop JA Knottnerus 《Canadian Metallurgical Quarterly》1994,14(3):208-216
Scoring models based on history and physical examination have been developed to discriminate patients with non-organic gastrointestinal disease from those who have organic disease. The application of these models may lead to more efficient diagnosis and prevent somatization. Although the models have high diagnostic accuracy in the population in which they have been developed, their value in other populations has not been established. In this study previously developed models were tested in validation populations defined by the original selection criteria from the studies in which the models were developed and in unselected general practice and outpatient populations. The diagnostic performance of the models are expressed in terms of odds ratio and sensitivity and specificity for the classification of patients as having organic and non-organic disease. The diagnostic performance of all the models were rather low in the validation populations. Relatively few elements of the models had independent diagnostic value. In addition, the correlation between the scoring models, expressed in Cohen's kappa, was extremely low. The diagnostic values of the scoring models were not reproduced in comparable and unselected populations. Therefore, it is concluded that the diagnostic value of such a model has little external validity. 相似文献
75.
The negative environmental impacts of burning fossil fuels have forced the energy research community seriously to consider renewable sources, such as naturally available solar energy. This paper provides an overview of solar thermoelectric (TE) cooling systems. Thus, this review presents the details referring to TE cooling parameters and formulations of the performance indicators and focuses on the development of TE cooling systems in recent decade with particular attention on advances in materials and modeling and design approaches. Additionally, the TE cooling applications have been also reviewed in aspects of electronic cooling, domestic refrigeration, air conditioning, and power generation. Finally, the possibility of solar TE cooling technologies application in “nearly zero” energy buildings is briefly discussed, and some future research directions are included. This research shows that TE cooling systems have advantages over conventional cooling devices, including compact in size, light in weight, high reliability, no mechanical moving parts, no working fluid, being powered by direct current, and easily switching between cooling and heating modes. 相似文献
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Marius Beul Matthias Nieuwenhuisen Jan Quenzel Radu Alexandru Rosu Jannis Horn Dmytro Pavlichenko Sebastian Houben Sven Behnke 《野外机器人技术杂志》2019,36(1):204-229
The Mohamed Bin Zayed International Robotics Challenge (MBZIRC) 2017 has defined ambitious new benchmarks to advance the state‐of‐the‐art in autonomous operation of ground‐based and flying robots. This study covers our approaches to solve the two challenges that involved micro aerial vehicles (MAV). Challenge 1 required reliable target perception, fast trajectory planning, and stable control of an MAV to land on a moving vehicle. Challenge 3 demanded a team of MAVs to perform a search and transportation task, coined “Treasure Hunt,” which required mission planning and multirobot coordination as well as adaptive control to account for the additional object weight. We describe our base MAV setup and the challenge‐specific extensions, cover the camera‐based perception, explain control and trajectory‐planning in detail, and elaborate on mission planning and team coordination. We evaluated our systems in simulation as well as with real‐robot experiments during the competition in Abu Dhabi. With our system, we—as part of the larger team NimbRo—won the MBZIRC Grand Challenge and achieved a third place in both subchallenges involving flying robots. 相似文献
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Catalin Croitoru Anca Maria Varodi Maria Cristina Timar Ionut Claudiu Roata Elena Manuela Stanciu Alexandru Pascu 《Journal of Materials Science》2018,53(6):4132-4143
The improvement of wood-plastic composites properties by additives and compatibilizers is a critical issue to produce value-added materials. High-density polyethylene-wood composites have been obtained through compression molding at 140 °C, using two types of additives, namely methyltrioctylammonium bis (trifluoromethylsulfonyl)imide and trihexyltetradecylphosphonium bis (2,4,4-trimethylpentyl) phosphinate room temperature ionic liquids. The ionic liquids improve the interfacial adhesion between the wood and the polymer phases, contributing to an increased stability of the material to water action and to an improved impact resistance and tensile strength in comparison with the reference. Also, the FTIR spectroscopy tests have proven a higher resistance of the ionic liquid-containing composites to accelerated photooxidation. Preliminary screening tests have also proven the antifungal character of the ionic liquids used in this study against brown rot (Postia placenta). This study opens new insights in the domain of polymeric composite materials, through documenting the possibility of blending new types of chemically distinct materials, difficult to be achieved by traditional functionalization/derivatization routes. 相似文献
80.
Self-cleaning, high transmittance glazing was obtained by cold spray deposition for glazings. The thin films contain \(\hbox {TiO}_{2}\), \(\hbox {SiO}_{2}\) and Au nanoparticles in different structures which allow for tailoring the optical, hydrophilic and photocatalytic properties. The crystallinity, morphology and surface energy were correlated with the optical transmittance and reflectance; the transmittance increased from 89.45 (for the glass substrate) to 91.76% when Au nanoparticles were used in the tandem layered structures. The samples containing alternating multi-layered \(\hbox {SiO}_{2}\) and \(\hbox {TiO}_{2}\) thin films without gold nanoparticles show hydrophilic surface; for these layers, the photocatalytic efficiency reaches 40% under simulated solar radiation. A conditioning effect based on adsorption was observed to increase the photocatalytic efficiency. These highly transparent coatings are well suited for glazings and fenestration, showing the self-cleaning effect based on combined superhydrophilicity and photocatalysis. 相似文献