Based on the near-surface atmospheric turbulence observation in the National Observation and Research Station of Desert Meteorology, Taklimakan Desert of Xinjiang in July 2016, the characteristics of turbulent transport in the unstable atmospheric surface layer in the hinterland of Taklimakan Desert are investigated. With the methods of eddy covariance, quadrant analysis, and spectra analysis, the dissimilarity between the turbulent transport of heat and momentum under different atmospheric instability is analyzed, and its potential physical mechanism is further explored. The results indicate that, under near-neutral conditions, the turbulent transport of heat and momentum is similar. However, as the atmospheric instability increases, the transport dissimilarity between heat and momentum becomes increasingly significant. Heat is transported more efficiently than momentum, while the turbulent transport of momentum shows a great randomness under the strongly thermal condition. This dissimilarity is closely related to the topology of turbulent coherent structures. Under unstable conditions, the coherent structure is dominated by thermal plume. It can induce synchronous changes in potential temperature and vertical velocity, but is difficult to lead corresponding changes in horizontal velocity. The difference in the physical mechanism of turbulent motion is the main reason for the significant dissimilarity between the turbulent transport of heat and momentum with increasing atmospheric instability.

Based on Byrnes’ definition and theory of critical thinking, through the research of approximately 1000 college and adult subjects, the authors have determined the structure of critical thinking of Chinese people and compiled the corresponding scale. In order to verify Byrnes’s theory of critical thinking structure, the authors first interviewed 40 subjects and generated a question bank for measuring critical thinking. Then, a preliminary scale was compiled. Second, an exploratory factor analysis was conducted on the data of 284 college students and the three dimensions of Chinese critical thinking — analytic ability, open-minded to criticism, and effort to use critical thinking, were obtained. Third, the authors conducted a confirmatory factor analysis on the data of 168 subjects, which confirmed the fit of the three-dimensional model. Finally, the data of 586 subjects were analyzed to further prove the reliability and validity of the scale. The result shows that the scale to measure the critical thinking of Chinese people conform to the theoretical constructs of Byrnes and colleagues. This scale has important theoretical and practical significance for future research in related fields.

Based on the observational data of a self-developed fast-response air pressure sensor at the Atmospheric Boundary Layer and Atmospheric Environment Comprehensive Experimental Station in the Horqin area, Inner Mongolia in the summer of 2019, the characteristic parameters of the pressure fluctuations were calculated, and the spectral characteristics of the pressure fluctuations and the characteristics of the pressure standard deviation were studied. The results show that the self-developed fast-response air pressure sensor can reflect the rapid fluctuations of pressure, and the frequency response is close to 1 Hz. The variance spectra of the pressure fluctuations satisfy the n^-2 scaling law in the frequency range from 0.0006 to 0.5 Hz, and the peak frequency is lower than that of the wind speed and temperature. The normalized variance spectra of pressure fluctuations under different atmospheric stabilities merge into a single line in the high-frequency range and distribute around the stability parameter in the low-frequency range. The contribution of pressure fluctuations to turbulent energy is mainly at larger scales, while that of the wind speed and temperature is mainly at smaller scales. The standard deviation and fluctuation intensity of the pressure have obvious diurnal variation characteristics, which is strong during the daytime and weak during the nighttime.

The authors use the high-frequency sampling function of the fine particle mass concentration measurement instrument E-Sampler and the eddy covariance method to calculate PM_2.5 concentration fluctuation and turbulent flux of the multiple pollution events of the Dezhou city atmospheric environment experimental station in Shandong Province from December 27, 2018 to January 7, 2019, and the turbulence characteristics of PM_2.5 concentration are discussed. The results show that the mean value of the turbulent flux of PM_2.5 concentration during the observation period is 0.026 μg/(m²·s). The transmission direction of the turbulent flux of PM_2.5 concentration in different pollution processes is different, indicating that the sink or source property is not static. With the increase of turbulence statistical characteristic quantities (such as turbulent kinetic energy, standard deviation of horizontal wind speed, standard deviation of vertical wind speed, horizontal wind speed, momentum flux and sensible heat flux), the vertical flux of PM_2.5 decreases exponentially, namely, it decreases sharply, and then changes little with the increase of each variable. With the increase of the concentration of PM_2.5, the absolute value of the turbulent flux of PM2.5 shows an increasing trend. The turbulent vertical flux of PM_2.5 concentration is related to the PM_2.5 concentration and the intensity of turbulence. The normalized standard deviation of PM_2.5 concentration and the stability parameter ζ = z/L follow the -1/3 power relationship under unstable conditions, that is σ_c/C_* = 6.7(-ζ)^-1/3. Under stable conditions, the experimental results are relatively discrete. In addition, the variance spectrum curve of PM_2.5 concentration satisfies the -2/3 power exponential rate in the high frequency range, and the covariance spectrum curve of the PM_2.5 concentration and the vertical wind speed satisfies the ?4/3 power exponential rate in the high frequency band. The result shows that 1 Hz high-frequency sampling function of E-Sampler can obtain continuous and effective turbulent flux of PM_2.5 concentration.

A comprehensive experiment on semi-arid underlying surface was carried out at the comprehensive experimental station of atmospheric science and atmospheric environment in Horqin, Inner Mongolia during July 3th to 16th in 2016. Using high-precision GPS sounding data of the atmospheric boundary layer (ABL), the structure of the ABL in the semi-arid North China under different weather conditions (sunny, cloudy and rainy) was analyzed. The atmospheric boundary layer height (ABLH) was determined by different methods and criteria. In addition, the characteristics of low-level jets (LLJs), surface turbulent flux and surface energy budget were discussed. The results indicate that the average height of the ABL is 1790 m during the day while it is 250 m at night when sunny. In the cloudy day, the average ABLH is 980 m in daytime and 430 m at night. The turbulent kinetic energy in the surface layer shows a strong correlation with ABLH at night. LLJs mostly occur at midnight, with an average altitude of approximately 390 m, and there is a positive correlation between the intensity and the altitude of LLJs.