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In this study, ceramic precursor fibers were prepared by a simple solution blowing spinning (SBS) method, and compressible, heat-resistant zirconia-doped alumina (ZDA) submicrometer fiber mats with a diameter of 400–800 nm were obtained by subsequent calcination. By doping ZrO2 in alumina fibers via the solution route, it can be confirmed by the analysis of the X-ray diffraction (XRD) patterns, Raman spectra, and transmission electron microscopy (TEM) images that the nano-t-ZrO2 formed at 1000 °C could retard the phase transition of Al2O3 from γ-phase to α-phase at high temperatures and effectively inhibit the growth of α-Al2O3 grains, then the consequent deterioration of mechanical properties and thermal stability could be alleviated. As a result, the ZDA submicrometer fiber mats exhibited improved compressibility and flexibility. The ZDA submicrometer fiber mats had thermal stability from −196 °C (liquid nitrogen) to above 1000 °C, making them suitable candidates for thermal insulation in extremely low-temperature environments and high-temperature industries. [ABSTRACT FROM AUTHOR]

With increasingly stringent emissions regulations, the trend toward using low-carbon fuels in internal combustion engines is unstoppable. Achieving higher rates of methane substitution is a crucial direction for future diesel-methane engines. However, the details of the combustion process involving the auto-ignition of micro pilot diesel fuel and ignition of methane main fuel to form premixed flames are still not clear. Therefore, the study employed visualization technique using a rapid compression machine and numerical study to analyze the process of igniting methane main fuel using various injection strategies for micro pilot diesel fuel. The results indicate that before the onset of the second diesel injection, a pale blue premixed flame had already formed within the cylinder, and the ignition delay of the second diesel injection was influenced by the presence of this premixed flame. The ignition delay of the diesel droplets from the second injection decreases gradually as SOI1 advances. Compared to the single injection strategy, the split injection strategy forms smaller high-temperature regions during the combustion process, thereby displaying a discernible trend toward reducing NOx emissions. Since the energy contribution of the second diesel injection is only 2%, the turbulence and diffusion flames formed by the second diesel injection have a relatively low impact on the propagation of the methane premixed flame. The flame front for single injection strategy is closer to the thickened flames region, suggesting a thicker flame surface due to the concentrated distribution of diesel. [ABSTRACT FROM AUTHOR]

With the tightening of emission regulations for marine engines, it has become increasingly important to explore efficient and clean combustion strategies in diesel–natural gas dual–fuel marine engines. This study, for the first time, compared and analyzed the effects of single and split injection strategies on the combustion process in a marine medium-speed dual-fuel engine with a natural gas substitution rate of 93.3%. Optimal strategies were compared for single injection [Case A: start of injection (SOI)=−15° crank angle (CA) after top dead center (ATDC)] and split injection (Case B: SOI1=−60°CA ATDC, SOI2=−10°CA ATDC). The analysis of Cases A and B revealed that employing a split pilot diesel injection strategy enhances engine thermal efficiency—Case B had a 0.77% increase in efficiency compared with Case A. More importantly, the split injection strategy proved to be more effective in reducing emissions; compared with Case A, Case B had a 36.3% and 49.4% decrease in NOx and CH4 emissions, respectively. A deeper examination of the combustion process in Case B revealed that the reactivity in specific cylinder regions was enhanced, thereby increasing the flame propagation speed in those areas. Moreover, the strategy reduced the proportion of pilot diesel diffusion combustion, leading to lower high temperatures and aiding in the reduction of NOx formation. These findings provide a technological reference for improving energy conversion efficiency and facilitating cleaner combustion in future applications of low-carbon fuels in dual-fuel marine engines. [ABSTRACT FROM AUTHOR]

The superior recognition ability and excitatory–inhibitory balance of the olfactory system has important applications in the efficient recognition, analysis, and processing of data. In this study, transistor synaptic devices are prepared utilizing poly‐diketo‐pyrrolopyrrole‐selenophene polymer (PTDPPSe‐5Si) with excellent electrical properties as the active layer, and dual‐gas pulses are applied for the first time to simulate excitatory and inhibitory behaviors in the olfactory system. Basic synaptic properties are successfully simulated, such as excitatory/inhibitory postsynaptic currents (EPSC/IPSC), and long‐term potentiation/depression (LTP/LTD). The regulation of excitatory–inhibitory balance in biomimetic olfaction is successfully simulated. This working mechanism is attributed to the capture and release of carriers in the channel induced by the gas's electron‐donating and electron‐withdrawing characteristics. The neuromotor pathway is constructed using synaptic devices as the key processing unit, which enables the integration of information from neurons and the output of information from motor neurons. A convolutional neural network is constructed to achieve recognition of eight common laboratory gas types and concentrations with a recognition accuracy of over 97%. The simulated excitatory and inhibitory behaviors exhibited by this device hold significant importance for the development of artificial neural networks, intelligent frameworks, and neural robots. [ABSTRACT FROM AUTHOR]

Multifunctional composite nanostructure prepared via electrospinning has attracted wide attention. In this study, Fe2O3-carbon composite nanofiber with particle–nanorod structure was successfully prepared via electrospinning and followed calcination. Then, the electromagnetic properties of this material have been fully characterized, and the influence of different preparation conditions on these properties has been studied. In addition, compared to pure γ -Fe2O3 nanoparticles and hollow Fe2O3 nanofibers, the composite nanofibers with a thickness of 2.64 mm exhibited an additional absorption peak at a frequency of 13.92 GHz and an enhancement in absorption at a frequency of 15.45 GHz, which may be attributed to the increase in electrical loss introduced by amorphous carbon and the enhanced magnetic loss resulting from the multi-stage reflection introduced by the particle–nanorod structure. This study shows that the composite of Fe2O3 and carbon, and the introduction of the particle–nanorod structure can improve the microwave absorption efficiency of materials, and more nanocomposites can be designed like this to further improve their electromagnetic properties and absorption efficiency in the future. Fe2O3-carbon composite nanofibers with particle–nanorod structure are obtained via electrospinning. The size of nanoparticle will increase with the increase of calcination temperature and time, and further electromagnetic and microwave test indicates that the microwave absorption efficiency of materials could be improved by the introduction of the particle–nanorod structure. [ABSTRACT FROM AUTHOR]

Objective: To explore the current domestic situation of the adverse event in acupotomy so as to promote the standardization of acupotomy and improve the clinical effect and safety of acupotomy therapy., Methods: The method of retrospective journal researching was used. The case report about the adverse event in acupotomy from CNKI, WANFANG and VIP databases was retrieved and the types, the features, the causes, the numbers of the papers and the cases were analyzed., Results: Fifty-eight papers were included, with total 343 cases. It was indicated that the adverse events in acupotomy were mainly postoperative local pain, hematoma, swelling, nerve damage, tendon rupture, adhesion, injury, infection, syncope, anesthesia accident, undeserved hormone use, etc. The lower level of standardization of acupotomy in the clinical use may lead to adverse events., Conclusion: Safe acupotomy treatment for some complicated diseases and dangerous parts remains to be improved, and the standardization of the acupotomy is an important approach to improve its safety. The related work needs to be carried out.