Fault Diagnosis of a Hydraulic Pump Based on the CEEMD-STFT Time-Frequency Entropy Method and Multiclass SVM Classifier

The fault diagnosis of hydraulic pumps is currently important and significant to ensure the normal operation of the entire hydraulic system. Considering the nonlinear characteristics of hydraulic-pump vibration signals and the mode mixing problem of the original Empirical Mode Decomposition (EMD) method, first, we use the Complete Ensemble EMD (CEEMD) method to decompose the signals. Second, the time-frequency analysis methods, which include the Short-Time Fourier Transform (STFT) and time-frequency entropy calculation, are applied to realize the robust feature extraction. Third, the multiclass Support Vector Machine (SVM) classifier is introduced to automatically classify the fault mode in this paper. An actual hydraulic-pump experiment demonstrates the procedure with a complete feature extraction and accurate mode classification

Rolling bearing fault diagnosis using improved LCD-TEO and softmax classifier

A novel rolling bearing fault diagnosis method based on improved local characteristic-scale decomposition (LCD), Teager energy operator (TEO) and softmax classifier is proposed in this paper. First, vibration signals are decomposed into several intrinsic scale components (ISCs) by using improved LCD; second, TEO and fast Fourier transform (FFT) are respectively used to extract instantaneous amplitude (IA) and frequency spectra of ISC1s, and then FFT is again employed to obtain spectra of IA; third, energy ratio of the resonant frequency band against the total, frequency entropy (FE) in the spectra of ISC1s and several amplitude ratios in the frequency spectra of demodulated ISC1s are extracted as fault feature vectors, and principal components analysis (PCA) is applied for dimensionality reduction; finally, these feature vectors are taken as inputs to train and test softmax classifier. As a new non-stationary signal analysis tool, LCD can decompose adaptively a signal into series of ISCs in different scales and give good results in situations where other methods failed. However, there are two main issues in this method, end effect and mode mixing, possibly leading to unexpected results. In this paper, a slope-based method and noise assisted analysis are applied to restrain the problems respectively. Experimental results show the proposed method performs effectively for bearing fault diagnosis

The Role of Paragus quadri-fasciatus Meigen on Aphid Control and the Observations of its Biological Characteristics

Four-strip small syrphid fly, Paragus quadri-fasciatus Meigen is the important natural enemy of aphids in our region. A fly can eat about 800 aphids during its whole life. There are more than 10 kinds of aphids can be food of this fly, such as soybean aphid, Chinese sorghum aphid and radish aphid etc. The fly has 3~4 generations each year in Tonghua county, Jilin province. The adult of the first generation appears after the last ten-day period of April each year. It takes 30~35 days to complete one generation. The fly can oviposit 84~124 eggs in its whole life. Major natural enemies of the fly are ichneumon wasps, spiders, lacewings and etc.Originating text in Chinese.Citation: Gao, Junfeng, Jiang, Lianfeng, Zhang, Guangxin, Li, Chunshan, Zhao, Guangquan. (1996). The Role of Paragus quadri-fasciatus Meigen on Aphid Control and the Observations of its Biological Characteristics. Journal of Jilin Agricultural Sciences, 5(2), 60-61

Dynamic Navigation Method with Multisubstations Based on Doppler Shift

The mobile terminals must be compensated for the Doppler effect in their moving communication. This special characteristic of mobile communication can be developed in some new applications. This paper proposes methods to realize mobile navigation calculation via Doppler shifts. It gives the theory of relationship between the motion parameters, like directions and speed, and frequency shifts caused by multibase stations. The simulation illustrates how to compute the movement parameters of numerical calculation and what should be care for the problem near angle 90 degree. It also gives an application with Google map and dynamical locating position and direction on a mobile phone by public wireless network. Given the simulation analysis and navigation test, the results show that this method has a good effect

Genome-Wide Profiling of Circular RNAs in the Rapidly Growing Shoots of Moso Bamboo (Phyllostachys edulis).

Circular RNAs, including circular exonic RNAs (circRNA), circular intronic RNAs (ciRNA) and exon-intron circRNAs (EIciRNAs), are a new type of noncoding RNAs. Growing shoots of moso bamboo (Phyllostachys edulis) represent an excellent model of fast growth and their circular RNAs have not been studied yet. To understand the potential regulation of circular RNAs, we systematically characterized circular RNAs from eight different developmental stages of rapidly growing shoots. Here, we identified 895 circular RNAs including a subset of mutually inclusive circRNA. These circular RNAs were generated from 759 corresponding parental coding genes involved in cellulose, hemicellulose and lignin biosynthetic process. Gene co-expression analysis revealed that hub genes, such as DEFECTIVE IN RNA-DIRECTED DNA METHYLATION 1 (DRD1), MAINTENANCE OF METHYLATION (MOM), dicer-like 3 (DCL3) and ARGONAUTE 1 (AGO1), were significantly enriched giving rise to circular RNAs. The expression level of these circular RNAs presented correlation with its linear counterpart according to transcriptome sequencing. Further protoplast transformation experiments indicated that overexpressing circ-bHLH93 generating from transcription factor decreased its linear transcript. Finally, the expression profiles suggested that circular RNAs may have interplay with miRNAs to regulate their cognate linear mRNAs, which was further supported by overexpressing miRNA156 decreasing the transcript of circ-TRF-1 and linear transcripts of TRF-1. Taken together, the overall profile of circular RNAs provided new insight into an unexplored category of long noncoding RNA regulation in moso bamboo

Reactions at Noble Metal Contacts with Methylammonium Lead Triiodide Perovskites: Role of Underpotential Deposition and Electrochemistry

Chemical reactivity of halide perovskites coupled with a low energy of formation makes it a challenge to characterize material properties and achieve long-term device stability. In this study, we elucidate electrochemical reactions occurring at the methylammonium lead triiodide (MAPbI3)/Au interface. X-ray photoemission spectroscopy is used to identify a type of reduction/oxidation reaction termed underpotential deposition (UPD) involving lead, iodine, and hydrogen occurring at interfaces with noble metals. Changes in surface compositions and oxidation states suggest that UPD derived adsorbates at MAPbI3/Au interfaces lower the energy barrier for release of volatile HI and/or I2catalyzing degradation at exposed contacts. Additionally, comparison to PbI2/Au interfaces demonstrates that the presence of methylammonium/methylamine accelerates the formation of a Pb0 adlayer on the Au. Reactions involving UPD Pb0 can transform the typically anodic (hole collecting) Au to a cathode in a photovoltaic measurement. Cyclic voltammetry reveals electrochemical reaction peaks in indium tin oxide (ITO)/MAPbI3/Au devices occurring within voltage ranges commonly used for perovskite characterization. The electrochemical stability window of this device architecture is measured to be between−0.5 V and 0.9 V. Voltage induced interfacial reactions contribute to reversible electrochemical peaks, hysteresis, switchable perovskite diode polarity, and permanent degradation at larger voltages. These types of surface reactions alter the interface/interphase composition beyond ion accumulation, provide a source for the diffusion of defects, and contribute to electrode material dependent current-voltage hysteresis. Moreover, the results imply fundamental limitations to achieving high device stability with noble metals and/or methylammonium containing perovskites

NRAV, a Long Noncoding RNA, Modulates Antiviral Responses through Suppression of Interferon-Stimulated Gene Transcription

SummaryLong noncoding RNAs (lncRNAs) modulate various biological processes, but their role in host antiviral responses is largely unknown. Here we identify a lncRNA as a key regulator of antiviral innate immunity. Following from the observation that a lncRNA that we call negative regulator of antiviral response (NRAV) was dramatically downregulated during infection with several viruses, we ectopically expressed NRAV in human cells or transgenic mice and found that it significantly promotes influenza A virus (IAV) replication and virulence. Conversely, silencing NRAV suppressed IAV replication and virus production, suggesting that reduction of NRAV is part of the host antiviral innate immune response to virus infection. NRAV negatively regulates the initial transcription of multiple critical interferon-stimulated genes (ISGs), including IFITM3 and MxA, by affecting histone modification of these genes. Our results provide evidence for a lncRNA in modulating the antiviral interferon response