Research on bearing current damage description model of variable frequency motor

The bearing failure seriously affects the normal operation of the motor. In this paper, the early damage of bearing wear caused by the shaft current in the operating state of the variable frequency motor is proposed. From the perspective of the bearing capacitance storage capacitor charge, the method based on analyzing the relationship between pitting pit size and shaft current per unit area of bearing track surface is proposed, so that the model can directly judge whether the bearing is in an absolutely safe running state. In this paper, the description model between the size of the pitting pit per unit area of the bearing track surface and the mechanical and electrical parameters is derived based on the assumption that the charge required for the formation of pitting pits per unit area of the bearing track surface. It is shown that the shaft current can promote the bearing to produce pitting pit, which leads to the early damage of the bearing, and the size of the pitting pit is positively related to the shaft current. Matlab/Simulink simulation verifies the correctness of the description model

Analysis of the response regulatory network of pepper genes under hydrogen peroxide stress

Hydrogen peroxide (H2O2) is a regulatory component related to plant signal transduction. To better understand the genome-wide gene expression response to H2O2 stress in pepper plants, a regulatory network of H2O2 stress-gene expression in pepper leaves and roots was constructed in the present study. We collected the normal tissues of leaves and roots of pepper plants after 40 days of H2O2 treatment and obtained the RNA-seq data of leaves and roots exposed to H2O2 for 0.5–24 h. By comparing the gene responses of pepper leaves and roots exposed to H2O2 stress for different time periods, we found that the response in roots reached the peak at 3 h, whereas the response in leaves reached the peak at 24 h after treatment, and the response degree in the roots was higher than that in the leaves. We used all datasets for K-means analysis and network analysis identified the clusters related to stress response and related genes. In addition, CaEBS1, CaRAP2, and CabHLH029 were identified through a co-expression analysis and were found to be strongly related to several reactive oxygen species-scavenging enzyme genes; their homologous genes in Arabidopsis showed important functions in response to hypoxia or iron uptake. This study provides a theoretical basis for determining the dynamic response process of pepper plants to H2O2 stress in leaves and roots, as well as for determining the critical time and the molecular mechanism of H2O2 stress response in leaves and roots. The candidate transcription factors identified in this study can be used as a reference for further experimental verification

Impacts of Upgrading of Consumption Structure and Human Capital Level on Carbon Emissions—Empirical Evidence Based on China’s Provincial Panel Data

Carbon emission reduction (CER) is increasingly becoming a global issue. This study explored the impact mechanism of upgrading of consumption structure (UCS) and human capital level (HC) on carbon emissions, and an empirical test was carried out using the provincial panel data from 2000 to 2019 in China. The results show the following: (1) China’s UCS could significantly curb carbon emissions. (2) At present, China’s HC is positively correlated with carbon emissions. The higher the level of human capital, the less conducive to CER. Additionally, the moderating effect of HC could inhibit the CER induced by UCS. (3) Regional heterogeneity analysis showed that the UCS in the central and western regions of China was conducive to CER, while the estimated coefficient of UCS on CER in the eastern region was not significant. (4) The UCS could reduce carbon emissions by stimulating the mediating effect of industrial upgrading. Based on empirical study results, this study proposes policy suggestions that can help reduce China’s carbon emissions

Impacts of Upgrading of Consumption Structure and Human Capital Level on Carbon Emissions—Empirical Evidence Based on China’s Provincial Panel Data

Carbon emission reduction (CER) is increasingly becoming a global issue. This study explored the impact mechanism of upgrading of consumption structure (UCS) and human capital level (HC) on carbon emissions, and an empirical test was carried out using the provincial panel data from 2000 to 2019 in China. The results show the following: (1) China’s UCS could significantly curb carbon emissions. (2) At present, China’s HC is positively correlated with carbon emissions. The higher the level of human capital, the less conducive to CER. Additionally, the moderating effect of HC could inhibit the CER induced by UCS. (3) Regional heterogeneity analysis showed that the UCS in the central and western regions of China was conducive to CER, while the estimated coefficient of UCS on CER in the eastern region was not significant. (4) The UCS could reduce carbon emissions by stimulating the mediating effect of industrial upgrading. Based on empirical study results, this study proposes policy suggestions that can help reduce China’s carbon emissions

Transcriptional Profiling at High Temporal Resolution Reveals Robust Immune/Inflammatory Responses during Rat Sciatic Nerve Recovery

After peripheral nerve injury, immune/inflammatory responses are triggered, which are critical for nerve regeneration. Despite their importance, the underlying molecular changes in immune/inflammatory responses remain largely unknown. In this study, we systematically analyzed differentially expressed genes in immune/inflammatory-related pathways at high temporal resolution and experimentally validated gene expression changes with RT-PCR following sciatic nerve crush in rats. We found that immune/inflammatory reactions not only occur in the acute injury but also remained activated over two weeks after injury. Detailed bioinformatic studies suggested that multiple immune/inflammatory pathways, including agranulocyte adhesion and diapedesis, granulocyte adhesion and diapedesis, IL-6 signaling, and IL-10 signaling, were sustained activated during nerve degeneration and regeneration. Our current study expands our understanding of the molecular basis of altered immune/ inflammatory-related pathways following injury and thus might offer the possibility of targeting related molecules as therapeutic intervention for peripheral nerve regeneration

Transcriptional Profiling at High Temporal Resolution Reveals Robust Immune/Inflammatory Responses during Rat Sciatic Nerve Recovery

After peripheral nerve injury, immune/inflammatory responses are triggered, which are critical for nerve regeneration. Despite their importance, the underlying molecular changes in immune/inflammatory responses remain largely unknown. In this study, we systematically analyzed differentially expressed genes in immune/inflammatory-related pathways at high temporal resolution and experimentally validated gene expression changes with RT-PCR following sciatic nerve crush in rats. We found that immune/inflammatory reactions not only occur in the acute injury but also remained activated over two weeks after injury. Detailed bioinformatic studies suggested that multiple immune/inflammatory pathways, including agranulocyte adhesion and diapedesis, granulocyte adhesion and diapedesis, IL-6 signaling, and IL-10 signaling, were sustained activated during nerve degeneration and regeneration. Our current study expands our understanding of the molecular basis of altered immune/inflammatory-related pathways following injury and thus might offer the possibility of targeting related molecules as therapeutic intervention for peripheral nerve regeneration

Mass Laplacian Discriminant Analysis and Its Application in Gear Fault Diagnosis

Fault diagnosis is essentially the identification of multiple fault modes. How to extract sensitive features and improve diagnostic accuracy is the key to fault diagnosis. In this paper, a new manifold learning method (Mass Laplacian Discriminant Analysis, MLDA) is proposed. Firstly, it is assumed that each data point in the space is a point with mass, and the mass is defined as the number of data points in a certain area. Then, the idea of universal gravitation is introduced to calculate the virtual universal gravitation between data points. Based on the Laplace eigenmaps algorithm, the gravitational Laplacian matrix between the same kind of data and the heterogeneous data is obtained, and the discriminant function is constructed by the ratio of the virtual gravitation between the heterogeneous data and the virtual gravitation between the similar data; the projection function with the largest discriminant function value is the optimal feature mapping function. Finally, based on the mapping function, the eigenvalues of the training data and the test data are calculated, and the softmax algorithm is used to classify the test data. Experiments on gear fault diagnosis show that this method has higher diagnostic accuracy than other manifold learning algorithms

Nitropyrazole based tricyclic nitrogen-rich cation salts: A new class of promising insensitive energetic materials

Nitrogen-rich compound 5,5′-(4-nitro-1H-pyrazole-3,5-diyl)-bis-(4H-1,2,4-triazole-3,4-diamine) (4) and its energetic salts (5–8) were synthesized. Compounds 4–7 posesse satisfactory mechanical sensitivity (IS > 40 J, FS > 360 N). 4 and 5 have the higher decomposition temperatures (4, 318 °C and 5, 304 °C) than TNT (TNT, 295 °C). Compared with TATB (8114 m•s−1), the calculated detonation velocity of 8 (8716 m•s−1) has a certain advantage. Multi-factor analysis shows that these compounds are promising nitrogen-rich energetic materials

The skeleton of 5,7-fused bicyclic imidazole-diazepine for heat-resistant energetic materials

In light of the low yields and complex reaction routes of some well-known 5,5-fused and 5,6-fused bicyclic compounds, a series of 5,7-fused bicyclic imidazole-diazepine compounds were developed with high yields by only two efficient steps. Significantly, the seven-membered heterocyclic ring has a stable energetic skeleton with multiple modifiable sites. However, the 5,7-fused bicyclic energetic compounds were rarely reported in the area of energetic materials. Three neutral compounds 1, 2 and 4 were synthesized in this work. To improve the detonation performances of the 5,7-fused neutral compounds, corresponding perchlorate 1a and 2a were further developed. The physicochemical and energetic performances of all newly developed compounds were experimentally determined. All newly prepared energetic compounds exhibit high decomposition temperatures (Td: 243.8–336 °C) and low mechanical sensitivities (IS: >15 J, FS: >280 N). Among them, the velocities performances of 1a (Dv = 7651 m/s) and 4 (Dv = 7600 m/s) are comparable to that of typical heat-resistant energetic material HNS (Dv = 7612 m/s). Meanwhile, the high decomposition temperature and low mechanical sensitivities (Td = 336 °C; IS = 32 J; FS > 353 N) of 4 are superior to that of HNS (Td = 318 °C; IS = 5 J; FS = 250 N). Hence, the 5,7-fused bicyclic compounds with high thermostability, low sensitivities and adjustable detonation performance have a clear tendency to open up a new space for the development of heat-resistant energetic materials