Light-emitting diodes (LEDs) have been regarded as the best artificial source of light for a plant factory. However, the effect of light quality on seedling production in such environments requires further study. On the basis of the practical application of light on cucumber seedlings (Ansha Company) in plant factories, the present investigation tracked and recorded the specific effects of red and blue light on the growth of the seedlings by analyzing the photo-biological mechanism involved. The growth parameters, as well as the photosynthetic characteristics of cucumber seedlings, were measured at different variations of light quality. The results showed that when the proportion of red light in the light source was higher than blue light, the height of the seedlings, leaf size, stem diameter, Dixon Quality Index (DQI), relative chlorophyll content, and the net photosynthetic rate were higher than those of the experimental group with a relatively high proportion of blue light. In the case of R7B3 (70% red light and 30% blue light), the stem diameter, DQI, and net photosynthetic rate of seedlings were 14%, 57%, and 22% higher than the minimum value, respectively. The present study analyzed the influence of red and blue light on plant growth characteristics during actual production and provides standardization for it.
This study comprehensively investigates the impact of varying red-to-blue light ratios on the growth of Spanish lettuce. The research considers various factors such as growth morphology, photosynthetic parameters, and chlorophyll fluorescence....
5 November 2020 in ECS Journal of Solid State Science and Technology
CsPbBr 3 :xBi 3+ quantum dot glass was prepared by using traditional melting-quenching and heat treatment processes. The effects of Bi doing on the sinter of the precursor of glass and the crystalline of the perovskite quantum dot were discussed detailly. By doping Bi 2 O 3 into the borosilicate glass matrix, the melting temperature was reduced to 900 °C. The tunable emission of CsPbBr 3 quantum dots from 523 to 493 nm was achieved with suitable Bi 2 O 3 doping. Due to the protection of the inorganic glass matrix, the prepared CsPbBr 3 quantum dots still exhibit excellent thermal stability after multiple thermal cycles and thermal shocks. This provides a good solution to the problem of poor thermal stability of perovskite quantum dots.
1 January 2021 in Aerosol and Air Quality Research
Levels, compositions, sources and health risk of PM2.5-bound PAHs were measured at a regional monitoring site of Huang-gang in the winter of 2018. Samples were collected every morning, afternoon, evening and late night (LN). The average concentrations of PM2.5 and PAHs were 110.4 ± 48.3 μg m-3 and 25.6± 12.0 ng m-3, respectively. The concentration of PM2.5 was in the order of evening > morning > afternoon > LN, while PAHs concentration was in the order of evening > LN > morning > afternoon. According to PM2.5 concentration and its changing trend, the haze can be divided into three stages: early (low concentration, January 13–15, EHZ), medium (high concentration, January 16–22, MHZ) and late (concentration decreased rapidly, January 23–24, LHZ). A positive correlation (P < 0.01) was observed between PM2.5 and ∑16PAHs concentration only in MHZ. Besides, PAHs concentration was positively related to NOX concentration, CO concentration and temperature but negatively correlated with RH, independent of O3 concentration. The ratios of OC/EC indicated that the secondary aerosol had a great influence on the formation of haze. Three sources of PAHs including traffic emission, coal combustion and biomass combustion were extracted and quantified, accounting for 54.4%, 13.3% and 32.3% of PAHs, respectively. Potential source contribution function (PSCF) and concentration weighted trajectory (CWT) indicated the transmission of PM2.5 from Wuhan and local pollutant emission were crucial to the formation of haze. BaPeq concentration combined with ILCR values was used to evaluate health risk and the results showed this haze had potential health risk to both adults and children.
There is an obvious colloid state in sauce-flavor liquor due to its unique brewing process and long storage time, which is an important quality feature of sauce-flavor. Aiming at the problems of time, cost, and the strong professionalism of the traditional quality identification method, we proposed a method to identify the quality of sauce-flavored liquor based on the Tyndall phenomenon. The influence of different wavelengths of light on the light scattering in liquor was explored, and it was concluded that the ultraviolet and blue light bands have a certain efficiency in the identification of liquor. Additionally, we analyzed the relationship between the particle size uniformity of liquor colloids and liquor quality according to the Tyndall phenomenon. We found that higher quality liquor has a brighter and lighter Tyndall path and a smaller light flooding angle due to the uniformity of the particles in it. This method can be used to achieve qualitative identification and is suitable for the identification of sauce-flavored liquor.