Review of Aircraft Vibration Environment Prediction Methods

AbstractAircraft vibration response environment prediction, which is adopted in aircraft initial vehicle development, has not been got enough attention and wide application yet. This paper briefly reviews theoretical and engineering significance of aircraft vibration response environment prediction firstly. Then the paper summarizes the main aircraft vibration response environment prediction methods and indicates their advantages, disadvantages and applicability scopes, including extrapolation of similar structure, theory analysis and analytical solution of differential dynamical equation, statistical parameter modeling, simulation calculation modeling and machine learning. Finally, the paper points out that uncertainty and non-linear structures, nonstationary signal analysis and complex vibration environment response prediction are major problems for aircraft vibration response prediction and directions for future research work

Linear Thermodynamics of Rodlike DNA Filtration

Linear thermodynamics transportation theory is employed to study filtration of rodlike DNA molecules. Using the repeated nanoarray consisting of alternate deep and shallow regions, it is demonstrated that the complex partitioning of rodlike DNA molecules of different lengths can be described by traditional transport theory with the configurational entropy properly quantified. Unlike most studies at mesoscopic level, this theory focuses on the macroscopic group behavior of DNA transportation. It is therefore easier to conduct validation analysis through comparison with experimental results. It is also promising in design and optimization of DNA filtration devices through computer simulation.Singapore-MIT Alliance (SMA

Autophagy Is a Defense Mechanism Inhibiting Invasion and Inflammation During High-Virulent Haemophilus parasuis Infection in PK-15 Cells

Bacterial infections activate autophagy and autophagy restricts pathogens such as Haemophilus parasuis through specific mechanisms. Autophagy is associated with the pathogenesis of H. parasuis. However, the mechanisms have not been clarified. Here, we monitored autophagy processes using confocal microscopy, western blot, and transmission electron microscopy (TEM) and found that H. parasuis SH0165 (high-virulent strain) but not HN0001 (non-virulent strain) infection enhanced autophagy flux. The AMPK/mTOR autophagy pathway was required for autophagy initiation and ATG5, Beclin-1, ATG7, and ATG16L1 emerged as important components in the generation of the autophagosome during H. parasuis infection. Moreover, autophagy induced by H. parasuis SH0165 turned to fight against invaded bacteria and inhibit inflammation. Then we further demonstrated that autophagy blocked the production of the cytokines IL-8, CCL4, and CCL5 induced by SH0165 infection through the inhibition of NF-κB, p38, and JNK MAPK signaling pathway. Therefore, our findings suggest that autophagy may act as a cellular defense mechanism in response to H. parasuis and provide a new way that autophagy protects the host against H. parasuis infection

Processing of Pheromone Information in Related Species of Heliothine Moths

In heliothine moths, the male-specific olfactory system is activated by a few odor molecules, each of which is associated with an easily identifiable glomerulus in the primary olfactory center of the brain. This arrangement is linked to two well-defined behavioral responses, one ensuring attraction and mating behavior by carrying information about pheromones released by conspecific females and the other inhibition of attraction via signal information emitted from heterospecifics. The chance of comparing the characteristic properties of pheromone receptor proteins, male-specific sensory neurons and macroglomerular complex (MGC)-units in closely-related species is especially intriguing. Here, we review studies on the male-specific olfactory system of heliothine moths with particular emphasis on five closely related species, i.e., Heliothis virescens, Heliothis subflexa, Helicoverpa zea, Helicoverpa assulta and Helicoverpa armigera

Review of Statistical Induction Analysis Methods on Aircraft Vibration Test Data

AbstractThe development of reliability and environment vibration test conditions depends on the processing of vibration test data. Because of randomness of vibration sources and different purposes of reliability testing and environmental testing, testing data should be dealt with different methods. This paper summarizes various statistical induction analysis methods for aircraft vibration test data, and indicates their advantages, disadvantages and applicability scope. Statistical analysis method on small sample, time-varying structures, non-stationary data processing and vibration environment prediction are the further research directions

Processing of pheromone information in related species of Heliothine moths

In heliothine moths, the male-specific olfactory system is activated by a few odor molecules, each of which is associated with an easily identifiable glomerulus in the primary olfactory center of the brain. This arrangement is linked to two well-defined behavioral responses, one ensuring attraction and mating behavior by carrying information about pheromones released by conspecific females and the other inhibition of attraction via signal information emitted from heterospecifics. The chance of comparing the characteristic properties of pheromone receptor proteins, male-specific sensory neurons and macroglomerular complex (MGC)-units in closely-related species is especially intriguing. Here, we review studies on the male-specific olfactory system of heliothine moths with particular emphasis on five closely related species, i.e., Heliothis virescens, Heliothis subflexa, Helicoverpa zea, Helicoverpa assulta and Helicoverpa armigera

Review of Vibration Signals Trend Forecasting Methods

AbstractVibration signals are important information for system failures. Forecasting the trend of vibration signals is an important content of condition monitoring, life estimation and fault diagnosis. The advantages, disadvantages and applicable scope of current trends and main methods on vibration signals forecasting, including time series analysis, grey prediction, ANN (artificial neural networks), SVM (support vector machine) are reviewed in this paper. Difficulties and problems existing in vibration signals forecasting and further research directions, including nonlinear and non-stationary signal processing, combining forecasting method, information fusion technology are then put forward. Finally, this paper proposes that the above methods and prospects should be developed into software system for engineering application