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排序方式: 共有564条查询结果,搜索用时 31 毫秒
141.
Jens Popper Marius BLugel Hagen Burchardt Steffen Horn Joachim Merx Dr.Detlev Richter Werner Varro Michael Pfeifer Pascal Staub-Lang 《仪器仪表标准化与计量》2019,(4)
SmartFactory~(KL)工作组1 "智能基础设施"专门处理模块化工业4.0生产设施的安全问题。其旨在提供一种工厂结构,通过模块化等手段确保其灵活性和可变性。本安型模块具有常规的功能安全性。但是,模块间依然存在依赖关系。在支持未知模块的模块化系统中,还需要一个新的安全体系结构。去年,该概念被整合到了工业4.0生产设施中,以实例证明该概念可在当今技术的基础上得以实施。在安全和机器通信的实施中,仅采用了一条单线共存。机器和机器模块可以在运行期间插入生产线或从生产线移除,而不会影响工厂的其它部分。必要的安全相关参数将根据此处导入的安全配置文件自动进行协商、配置和发布。要求如下文所述。 相似文献
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Anca Dumbrava Daniela Berger Cristian Matei Marius Daniel Radu Emma Gheorghe 《Ceramics International》2018,44(5):4931-4936
Zinc oxide was deposited onto calcium carbonate precipitated using a template of polysaccharides from Ulva lactuca green seaweeds (Black Sea). The resulted composite material was characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, UV–vis and FTIR spectroscopy. The therapeutic effect of prepared composite material was assessed in vivo as a topical application for the burns treatment and compared with that of ZnO. An increased antioxidant activity by combining zinc oxide with calcium carbonate capped with polysaccharides from green seaweeds extract in a composite material was demonstrated. 相似文献
146.
Corneliu Hamciuc Elena Hamciuc Marius Olariu Romeo Ciobanu 《Polymer International》2010,59(5):668-675
Aromatic polyimides are high‐performance polymers used in applications demanding service at enhanced temperature while maintaining their structural integrity and excellent combination of chemical, physical and mechanical properties. The incorporation of various metallic additives into a polyimide matrix improves its properties, leading to materials required by specific applications. Hybrid polyimide films containing barium and titanium oxides having thicknesses in the range of tens of micrometres were prepared. These films were obtained using the sol–gel technique starting from a poly(amic acid) and a soluble precursor of metal oxides. They exhibited good thermal stability having an initial decomposition temperature above 460 °C, and a glass transition temperature in the range 217–238 °C. Two subglass transitions, γ and β, were evident from dynamic mechanical analysis and dielectric spectroscopy. A study of the thermal and electrical behaviour of some hybrid polyimide films containing barium and titanium oxides is presented. On increasing the concentration of metal oxides, an increase of dielectric constant and a decrease of thermal stability of the hybrid films were observed. The presence of metal oxides shifted the glass transition temperature and the temperature of the β transition to higher values. Copyright © 2009 Society of Chemical Industry 相似文献
147.
Samuel Solarski Manuela Ferreira Eric Devaux Gaëlle Fontaine Pierre Bachelet Serge Bourbigot René Delobel Philippe Coszach Marius Murariu Amália Da Silva Ferreira Michael Alexandre Philippe Degee Philippe Dubois 《应用聚合物科学杂志》2008,109(2):841-851
An experimental study was carried out to design polylactide (PLA)-clay nanocomposites for developing fibers. PLA and 1–10 wt % of a selected organomodified bentonite (Bentone® 104-B104) were melt mixed to examine the effect of processing conditions (temperature, shear, residence time) on the morphology of performed polymer nanocomposites (PNC). Because of a good compatibility with PLA matrix, the dispersion of B104 occurred under different conditions without difficulty, and a similar morphology was obtained. The results obtained showed that at low temperature of mixing, the shear stress exerted on polymer has a key role on the extent of intercalation and delamination. Upscale experiments were further performed using optimized conditions and 4 wt % B104 was added to PLA matrix by melt blending to produce PNC for spinning. Then, the recovered PNC were melt spun to produce multifilaments yarns, and it was demonstrated that surprisingly, it is not necessary to use a plasticizer to spin a blend with 4 wt % B104. The properties of the yarns have been studied in terms of clay dispersion as well as thermal, mechanical, and shrinkage properties. B104 could be added up to 4 wt % into PLA without detrimentally sacrificing the tensile strength of melt-spun filaments, especially at high draw ratio. Interestingly, the PNC-based multifilaments were knitted and the flammability studied using cone calorimeter at 35 kW/m2. A strong decrease, up to 46%, of the heat release rate was measured. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
148.
Azhar Fakharuddin Marius Franckevičius Andrius Devižis Andrius Gelžinis Jevgenij Chmeliov Paul Heremans Vidmantas Gulbinas 《Advanced functional materials》2021,31(15):2010076
Heterogeneous organic-inorganic halide perovskites possess inherent non-uniformities in bandgap that are sometimes engineered and exploited on purpose, like in quasi-2D perovskites. In these systems, charge carrier and excitation energy migration to lower-bandgap sites are key processes governing luminescence. The question, which of them dominates in particular materials and under specific experimental conditions, still remains unanswered, especially when charge carriers comprise excitons. In this study transient absorption (TA) and transient photoluminescence (PL) techniques are combined to address the excited state dynamics in quasi-2D and other heterogeneous perovskite structures in broad temperature range, from room temperature down to 15 K. The data provide clear evidence that charge carrier transfer rather than energy migration dominates in heterogeneous quasi-2D perovskite films. 相似文献
149.
A novel method for measuring and calculating volumetric strain in circular cylindrical uniaxial tension samples made from polymeric materials is proposed. It is shown that special considerations must be taken when calculating volumetric strain when a sample is in a postnecking state. Solely based on surface data, the key feature of the proposed correction is that it allows for an inhomogeneous distribution of longitudinal strain through the diameter of the sample, where a more traditional approach would be to assume a homogeneous distribution. These two approaches are evaluated by applying them to data from a close‐to‐incompressible steel sample. Whereas the proposed method indicates only a small positive increase in volume, the assumption of a homogeneous distribution results in substantial negative volumetric strains. Applying the two methods to tension samples made from HDPE and PVC, where plastic dilatation is nonlinear, again shows an initial negative volumetric strain for HDPE with the assumption of a homogeneous longitudinal strain. The proposed method predicts close‐to‐zero early‐stage volumetric strain for the same test. The differences are more subtle for samples of PVC. Micrographs obtained with scanning electron microscope show that the dilatation of PVC is related to voiding of the material around filler particles, while the underlying mechanism for HDPE is less clear. The results indicate that earlier reports of negative volumetric strain in polymers subjected to uniaxial tension might be artefacts of the implicit assumption made when calculating the volumetric strain. 相似文献
150.
The ‘intelligent container’ represents a novel transport system with the ability to make autonomous decisions regarding the condition of its transported goods. For example, fruit in cold chain logistics networks is very sensitive to mould and tends to perish. This can cause huge losses during transport, because the state-of-the-art reefer containers are able to control the temperature but not in relation to the fruit condition. The ‘intelligent container’ is able to precisely monitor the condition of fruit, as well as track its geographical position. Thus, the transport losses can be reduced due to better climate control and enhanced distribution strategies. This paper focuses on the development of a new scheduling method for distribution by applying principles of quality-driven customer order decoupling corridors (qCODC). Such corridors allow the dynamic change of allocations of container to customer order assignments. These corridors increase the flexibility of the decision-making process. Therefore, a simulation model will be developed and used in order to evaluate the potential of the new scheduling method based on the concept of the ‘intelligent container’ and qCODC. 相似文献