Analysis of the Spectral Characteristics of Triggered Lightning

The spectra with wavelength range of 390 nm to 660 nm of triggered lightning were observed in Guangdong Area using a slitless spectrograph. The characteristics of the lightning spectra during the initial continuous current and return strokes were analyzed, and the differences between the metal section and air section of the lightning channel were compared. The results showed that the metal spectra were contained in the metal section during the initial continuous current. As for the lightning channel of the return strokes, the line spectra for both the metal section and the air section were identical;neither of the two sections contained the metal spectra, but the relative intensity of its emission spectrum was different. Owing to different radiation mechanisms, the spectral structures and luminance of the two sections were not the same. Combined with the current data, it was found that there was a good positive correlation between the total spectral strength and the transferred charge. The total intensity of the lightning channel spectrum increased with the height of the channel, indicating that the radiation sequence of the lightning channel was different. High temporal resolution observations showed that the spectral line duration could be divided into three categories, in which the lines with higher excitation energy appear first and decay rapidly, while those with lower excitation energy appear later but last longer.

Based on Fluent Numerical Calculation of Refractive Index on Rocket Engine Nozzle Plume

Numerical 2D simulation and research on internal flow field and external flow field of rocket motor nozzle using FLUENT software. Analyze the flow condition of internal flow field and external flow field, and according to add in the amount of the different gas components, obtain the clear distribution of contour of density flow field, pressure flow field and various material components and so on. Simulation results agree with the results observed from the test on the ground, and provide reference for solid rocket motor development.

Diagnostic Value of Combined Detection of Galectin-3 and N-Terminal B-Type Natriuretic Peptide in Patients with Acute Heart Failure

Background: Acute heart failure timely and effective diagnosis and treatment directly affects the prognosis of patients, so early diagnosis of acute heart failure treatment is very important. The current diagnosis of acute heart failure has yet to be further improved. To investigate the relationship between plasma levels of Galectin-3 and NT-proBNP in cardiac structure and function in patients with acute heart failure (AHF) Early detection of failure. Methods: The clinical data of 86 patients with acute heart failure in our hospital were analyzed and followed up. Twenty-six healthy subjects with normal cardiac function were used as control group. The plasma Galectin-3 and NT-proBNP levels were compared between the two groups to observe the value of plasma Galectin-3 combined with NT-proBNP in the diagnosis of acute heart failure. Results: There was no significant difference in the level of Galectin-3 and NT-proBNP between heart function group II and control group, and the levels of cardiac function III and IVG plasma Galectin-3 and NT-proBNP were significantly higher in patients with heart failure Compared with the healthy control group, the patients’ LVEF decreased and their cardiac function increased. The levels of plasma Galectin-3 and NT-proBNP increased significantly (P 0.01). Multivariate Logistic regression analysis demonstrated that plasma levels of Galectin-3 and NT-proBNP were independent of cardiac function. The area under the ROC curve for the combined detection of plasma Galectin-3 and NT-proBNP was greater than the area under the two alone tests. Conclusion: The combined detection of Galectin-3 and NT-proBNP has high sensitivity and specificity in the diagnosis of acute heart failure and can be used as a new detection mode.