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Scientometrics - Computer-assisted methods and tools can help researchers automate the coding process of literature reviews and accelerate the literature review process. However, existing... 相似文献
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Electron Beam Welding is a well-established bonding method in macro applications. The properties of this method make it very promising for Microsystems, the very small possible beam diameter predestine this technology for the realisation of smallest spot or line welds of metal and also of non-metal materials with locally concentrated energy input into the component. The wearless and inertia-free beam allows highly dynamic joining processes. Where even smallest particles of dust can influence the results, the processing inside a vacuum chamber protect the components to a high degree from contamination and oxide formation during the welding cycle. In this study, the process is downscaled by modifying a scanning electron microscope (SEM), which operates according to the same principle as an electron beam welding machine. This creates the possibility to observe and weld the components with the same device. The necessary modifications are investigated, as well as the possibilities to expand the device, which makes it a promising tool for the flexible production of hybrid Microsystems. The presented investigations and results are acquired within the project SFB 440 “Assembly of Hybrid Microsystems”, financed by the “German Society for Research” (DFG). 相似文献
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Sascha Stanic Thomas Koch Klaus Schmid Simone Knaus Vasiliki-Maria Archodoulaki 《应用聚合物科学杂志》2021,138(28):50659
The influence of two peroxides (peroxydicarbonate/dilauroyl peroxide) with various concentrations (10–200 mmol/kg PP) and their effective opportunity to introduce long chain branched (LCB) were investigated. The dependence of a single and double extrusion step and the changes of the properties were studied. Experiments were carried out in a single screw extruder at 180°C for the first extrusion step (modification) and at 240°C for the second extrusion step (processing simulation). Melt flow rate and dynamic rheological properties were studied at a measuring temperature of 230°C. For the definitive determination of long chain branched polypropylene (LCB-PP) served the extensional rheology measurements. The mechanical properties were examined via tensile test and impact tensile test. Summarized, LCB (melt strength) could be observed via extensional rheology for all modified specimens and the mechanical properties were maintained or even improved for the modified samples. Particularly, samples containing dilauroyl peroxide display excellent mechanical properties in this study. 相似文献
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The article considers the history of electroshock therapy as a history of medical technology, professional cooperation and business competition. A variation of a history from below is intended; though not from the patients’ perspective (Porter, Theory Soc 14:175–198, 1985), but with a focus on electrodes, circuitry and patents. Such a ‘material history’ of electroshock therapy reveals that the technical make-up of electroshock devices and what they were used for was relative to the changing interests of physicians, industrial companies and mental health politics; it makes an intriguing case for the Social Construction of Technology theory (Bijker et al., The social construction of technological systems: new directions in the sociology and history of technology. MIT Press, Cambridge, MA, 1987). 相似文献
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Sascha Kuhn August Burr Michael Kübler Matthias Deckert Christoph Bleesen 《Microsystem Technologies》2010,16(10):1787-1801
The injection molding of micro-structures is a promising mass-production method for a broad range of materials. However, the
replication quality of these structures depends significantly on the heat flow during the filling stage. In this paper, the
filling and heat transfer of v-groove and random structures below 5 μm is investigated with the help of an AFM (atomic force
microscope) and thermo couples. A numerical model is developed to predict the filling of surface structures during the filling
and packing stage. The model implies the use of simple fully developed flow models taking the power-law material model into
account. This permits investigation into which ways several processing parameters affect the polymer flow in the surface structures.
The mold wall temperature, which has significant effects on the polymer flow, is varied by using a variothermal mold temperature
control system to validate the model proposed. 相似文献
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Chuanjun Liu Marcus C. Lopes Sascha A. Pihan Daniela Fell Mordechai Sokuler Hans-Jürgen Butt Günter K. Auernhammer Elmar BonaccursoAuthor vitae 《Sensors and actuators. B, Chemical》2011,160(1):32
We present a method to measure the absorption of water molecules from the liquid and the vapour phase into polymer nano-films and the diffusion inside these films. Film thickness can be down to 45 nm. To demonstrate the possibilities of this method we use polymer films that are deposited on the upper side of a silicon cantilever by plasma polymerization of norbornene. When a microdrop of water is deposited onto the initially straight cantilever, the drop causes the cantilever to bend while it evaporates. Evaporation of such small water drops usually takes less than a second. An upwards bending is due to capillary forces and a downwards bending is due to the diffusion of water into the polymer film – and the consequent volume expansion (swelling) of the film. The magnitude of the capillary forces and the extent of swelling continuously change during drop evaporation. When drop evaporation is over the cantilever returns to its initial straight position. We simulate the time dependent bending with a numerical model that qualitatively agrees with the experiment. From the time dependence of cantilever bending we are able to determine the diffusion coefficient of water in the thin polymer film. 相似文献