RESUMO
To investigate the effect of nonthermal plasma (NTP) on the microstructure and oxidation characteristics of particulate matter (PM) from diesel engines at different oxidation stages, a self-designed NTP reactor was used to conduct a time-varying oxidation test on PM samples. The oxidized PM samples were analyzed via thermogravimetric analysis and Raman spectroscopy. The results indicated that the effect of NTP could allow the elemental carbon (EC) to more easily start ignition. The oxidation activity of the EC decreased when the action time of the NTP was less than 5 min. Conversely, when the NTP action time was more than 5 min, the EC oxidation activity gradually increased. When the NTP was active for more than 10 min, it rapidly reacted with the EC, and the oxidation priority of the volatile fraction was higher than that of the EC. During the oxidation process, there are many forms of carbon structures in the particles and they have a mutual transmission relationship. The variation trend of the graphitization degree was consistent with that of the thermogravimetric results, indicating that the degree of graphitization directly affected the PM oxidation activity.
Assuntos
Poluentes Atmosféricos , Material Particulado , Carbono , Oxirredução , Tamanho da Partícula , Emissões de VeículosRESUMO
Graphite/epoxy resin (G/EP) composites are extensively utilized in bipolar plates for fuel cells owing to their outstanding electrical and mechanical properties. However, the mechanical strength of these composites declines notably due to the inadequate bonding interface between graphite and epoxy resin. To address this issue, we used molecular dynamics (MD) simulations to study the influence of graphite surface functionalization on the interfacial structures of composites. The results of this study revealed that the functionalization of the graphite surface led to an increase in the interface thickness of the composite. This phenomenon can be attributed to the interdiffusion and hydrogen bond formation between functionalized graphite and epoxy molecular chains. And all four types of functional groups demonstrated a promoting effect on the adsorption process. Additionally, the adsorption and contact angle results provided further evidence that the adsorption rate of graphite to the epoxy resin significantly improved after functionalization. These findings contribute to a more comprehensive understanding of the microscopic process of forming interfaces in G/EP composites. In addition, these insights provide valuable guidance for improving the interface bonding of composite bipolar plates, which can ultimately increase their mechanical strength.
RESUMO
The key technology of the device for the viviperception of the animal mesenteric microcirculation is to simulate the celiac environment in the device. The technical requirements of the device for microcirculation viviperception are that the observation box should be able to "keep warm, preserve moisture, continually perfuse, and fix the sample"; and the lighting should be "intense", "convergence", and "cool". After actual application, it was found that the newly designed and developed the device by research personnel of Wannan Medical College for the viviperception of the animal mesenteric microcirculation can meet the technical requirements, which is able to "keep warm, preserve moisture, continually perfuse, and fix the sample", and using LED lamp as the microscope light source is "intense", "convergence", and "cool". This device is ingenious and reasonable in design, stable in technology, convenient in operation, and competent in microcirculation viviperception. It solves the technical problem to simulate the celiac environment for mesenteric microcirculation viviperception. The device provides convenience to observe and study the microcirculation, which is worth to be applicated widely.