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This study aimed to examine the mediating effect of life satisfaction in the relationship between hope and internalizing/externalizing behaviors among a sample of 1170 Chinese adolescents (mean age = 14.80 ± 1.76 years, 46.24% boys). Through the use of structural equation modeling (SEM), the study revealed a negative association between hope and internalizing/externalizing behaviors. Furthermore, the findings indicated that life satisfaction partially mediated the relationship between hope and internalizing/externalizing behaviors. The findings highlight the significance of hope and life satisfaction as protective factors in reducing internalizing/externalizing behaviors among adolescents. These results also contribute to the existing research on the role of hope and emphasize the importance of fostering hope and enhancing life satisfaction in prevention and intervention programs targeting adolescent internalizing/externalizing behaviors. [ABSTRACT FROM AUTHOR]

Low-vacuum mass spectrometry (MS) is desirable because it reduces the size, weight, cost, and power of the instruments. A method was developed that uses Langevin collision theory to simulate the trajectory of ions in a low-vacuum environment. A low-vacuum simulation platform of cylindrical ion trap MS was then built in COMSOL Multiphysics based on this method. In comparison with the traditional damping force model, this approach described the motion of ions more accurately. The sensitivity and resolution of the instrument were simulated under different operating modes. The adoption of a small mass background gas, a higher frequency for the radio frequency voltage, a smaller ion trap size and a higher temperature allowed mass analysis to be conducted under low vacuum. In addition, the results were applied to experiment measurements, and excellent mass spectra of organic compounds were obtained up to a maximum pressure of 2 Pa, showing the effectiveness of the results obtained from the simulation. [ABSTRACT FROM AUTHOR]

Low-vacuum mass spectrometry is desirable because it reduces the size, weight, cost, and power of the instrument by reducing the workload of the pumping system. To investigate low-vacuum mass spectrometry methods, a cylindrical ion trap (CIT) instrument was built. The platform used an electron impact source as the ionization source, a custom CIT as the mass analyzer, and an electron multiplier as the ion detector. The dimensions of the CIT were r0 = 10 mm and z0 = 8.98 mm. Aiming at low-vacuum conditions, its working parameters were optimized. By increasing the frequency of the radio frequency (RF) voltage, optimizing the electron impact source, using a higher voltage on the electron multiplier, and improving the current preamplifier, the mass spectrometry of methyl salicylate was successively performed at helium buffer gas pressures up to 2 Pa, which was dozens of times higher than the upper pressure limit of ion trap mass spectrometers. More importantly, this pressure can be obtained using a single pump, avoiding the use of a bulky turbo pump. In addition, we measured and analyzed the mass deviation of methyl salicylate with the changes in the background gas pressure and RF voltage frequency. The results experimentally verified the theory that the stability regions expand with increasing pressure for the first time. The methods we explored could be used to develop next generation hand-portable instruments and bring new applications to mass spectrometry. [ABSTRACT FROM AUTHOR]