The apparent formation rates and growth rates, i.e., (3.3±3.1) cm-3·s-1 and (5.3±3.3) nm·h-1, decreased, although the decreases were not significant (P>0.05). The correlation analyses implied that AVOCs favored NPF. However, BVOCs had no correlation with NPF. For the cases in which new particles could grow to CCN sizes (>50 nm), the particle growth characteristics showed significant seasonal differences, i.e., in summer, new particles could grow to CCN sizes via photochemical reactions, whereas in winter, second-stage growth driven by the formation of nitrate aerosols was needed to grow new particles to CCN sizes.In order to study the pollution characteristics and causes of winter haze pollution in Beijing, a typical PM2.5 pollution process in Beijing in December 2019 was used as the analysis object using aerosol vertical detection data, boundary layer meteorological field and near-ground turbulence data, and the difference in haze. The characteristics of the pollution stage and the evolution of the physical and chemical characteristics of the boundary layer were comprehensively analyzed. The results showed that ① the pollution process in Beijing during the observation period lasted 5 d and experienced two generations and eliminations. The maximum hourly PM2.5 concentration was 220 μg·m-3 and the time exceeding the severe pollution standard was 64 h, thereby accounting for 53% of the total time. ② The aerosol optical properties and meteorological field observation data showed that the pollution originated from the regional transmission of aerosols and water vapor on the surface of the southwest urban agglomeration in event, and the response time is the same as the continuous turbulence intensity after the turbulence peak. In addition, the sensible heat fluxes on sunny days and haze days were both transported from the ground to the atmosphere, and showed clear daily single-peak changes. The sensible heat flux on haze days (20 W·m-2) was smaller than that on sunny days (60 W·m-2). The latent heat flux was approximately 0 W·m-2 in the whole process. ④ There was a feedback effect between the meteorological conditions of the pollution layer and the boundary layer. On the one hand, unfavorable diffusion of the meteorological conditions was conducive to the accumulation of pollution. On the other hand, the aerosol layer and water vapor cooling effect that accumulated near the ground were worse than the night cooling radiation on the inversion layer The contribution was greater, thereby further inhibiting the development of turbulent motion and ultimately resulting in increased pollution.The characteristics of meteorological conditions and pollutant concentrations were analyzed based on two pollution episodes before and after city heating in Beijing during February to March of 2019. this website The backward trajectory and WRF-CAMx models were used to analyze the evolution of pollutants before and after city heating, and the influences of meteorological conditions, regional transport, and secondary transformation on the episodes were discussed. There was little difference in the average ρ(PM2.5) between February 21-24 (episode 1) and March 18-20 (episode 2), with concentrations of 100.1 μg·m-3 and 97.2 μg·m-3, respectively. However, compared with that of episode 2, in episode 1 the average peak value was higher with two peak stages, the diurnal variation was clearer, and the process developed much more rapidly. Moreover, episode 1 was regional pollution, while episode 2 was more related to local pollution in Beijing. The SO2 concentrations in both episodes were not higher than 16 μg·m-3, thereby indicatinl transport. The simulation ability for the rapid growth of pollutants needs to be promoted, and the response of pollutant types to emission reduction and the feedback related to the atmospheric oxidant and aerosol properties may be important for the simulation effect, which all require further study.To explore the concentrations, characteristics, and sources of organic aerosols in winter in Beijing, atmospheric fine particulate matter (PM2.5) samples were collected from November 10, 2016 to December 10, 2016. One hundred and twenty-nine particulate organic matters (POM) were quantified by gas chromatography-mass spectrometry, accounting for approximately 9.3%±1.2% of the total concentration of organic matter. The most abundant class was sugar, among which levoglucosan alone accounted for 18% of the quantified organic matter mass. The next most abundant classes were alkanoic acids, normal alkanes, dicarboxylic acids, and polycyclic aromatic hydrocarbons. The influence of winter heating and biomass burning emissions on organic aerosols in winter in Beijing was analyzed by the characteristics of the molecular markers in the POM. Compared with those during the non-heating period, the concentrations and proportions of hopane species, which are tracers for fossil fuels, increased in the organic matters during ns could not be ignored. Therefore, the control of motor vehicle and cooking emissions is of great importance to reduce the problem of PM2.5 pollution in winter in Beijing.Leadership is central to effective nursing practice and is considered to be particularly important during crises such as the coronavirus disease 2019 (COVID-19) pandemic. This article examines several leadership styles that are commonly used in healthcare - namely the transactional, transformational and laissez-faire leadership styles - and considers their advantages and disadvantages in the context of the COVID-19 pandemic. It also explains the potential benefits of compassionate leadership in supporting the nursing workforce during this highly challenging and stressful period. Mid-infrared (MIR) light refers to wavelengths ranging from 3 to 30  μm and is the most attractive spectral region for ablation of soft and hard tissues. This is because building blocks of biological tissue, such as water, proteins, and lipids, exhibit molecular vibrational modes in the MIR wavelengths that result in strong MIR light absorption. To date, researchers investigating MIR lasers for surgical applications have used bulky light sources, such as free electron lasers, nonlinear light generators, and carbon dioxide lasers. We demonstrate the use of a tiny (a few microns wide, a few millimeters long) MIR interband cascade laser (ICL) for surgical thermal ablation applications. Our goal is to demonstrate the use of an ICL for surgical thermal ablation and demonstrate its efficacy in ablating normal fibroblasts and primary undifferentiated pleomorphic sarcoma tumor cells (C1619). We conducted Fourier transform infrared spectroscopy analysis of healthy and cancerous tissue samples, which indicated that the absorption of tumor tissue is higher than healthy tissue around 3.