Root turnover is a key process of terrestrial ecosystem carbon cycle, which is of great significance to the study of soil carbon pool changes and global climate change. However, because there are many measurement and calculation methods of root turnover, the results obtained by different methods are quite different, and the current research on root turnover of forest ecosystem on the global regional scale is not sufficient, so the change law of root turnover of global forest ecosystem is still unclear. By collecting literature data and unifying the calculation method of turnover rate, this study integrates the spatial pattern of fine root turnover of five forest types in the world, and obtains the factors affecting fine root turnover of forest ecosystem in combination with soil physical and chemical properties and climate data. The results showed that there were significant differences in fine root turnover rate among different forest types, and it gradually decreased with the increase of latitude; the turnover rate of fine roots in forest ecosystem is positively correlated with annual average temperature and annual average precipitation; fine root turnover rate of forest ecosystem is positively correlated with soil organic carbon content, but negatively correlated with soil pH value. This study provides a scientific basis for revealing the law and mechanism of fine root turnover in forest ecosystem.

Nanoporous nickel has been prepared by electrodeposition using non-ionic surfactant based liquid crystalline template under optimized processing conditions. Physicochemical properties of nanoporous nickel are systematically characterized through XRD, SEM and AFM analyses. Comparison of electrocatalytic activity of nanoporous nickel with smooth nickel was interrogated using cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) analyses. Distinctly enhanced electrocatalytic activity with improved surface poisoning resistance related to nanoporous nickel electrode towards methanol oxidation stems from unique nanoporous morphology. This nanoporous morphology with high surface to volume ratio is highly beneficial to promote active catalytic centers to offer readily accessible Pt catalytic sites for MOR, through facilitating mass and electron transports.

The properties of the beta batteries are compared, which are made on the basis of the different β-isotopes with beta decay. Tritium and Ni-63 make it possible to make β-sources of high activity, without harmful associated emissions, with low self-absorption, emitting high-energy β-electrons that penetrate deep into the semiconductor and generate a large number of electron-hole pairs. The efficiency of beta batteries needs to be analyzed based on the real energy distribution of β-electrons. It makes possible to obtain the real value of the energy absorbed inside the β-source, correctly estimate the amount of self-absorption of the β-electrons and part of the β-electronsthere is a penetrate into the semiconductor, the number of electrons and holes that are generated in the semiconductor, and the magnitude of the idling voltage. Formulas for these quantities are calculated in this paper.

The effects of Zn2+ stress on seed germination, seedling growth and chlorophyll content were studied in order to better understand the effect of heavy metal Zn on the growth and development of green plants. The concentration gradient of Zn2+ was 20, 50,100,150,200,300,500,700mg / L, and deionized water was used as control. The results showed that under the Zn2+ stress condition, the germination index of the rhubarb seeds increased with the increase of Zn2+ concentration. Germination potential, germination rate and germination index were the highest when Zn2+concentration was 100mg / L, the conductivity was the lowest at zinc concentration of 100mg / L, the root length, stem length and chlorophyll content of Zn2+ gradually reduced. The results showed that the amount of Zn2+ could promote seed germination, but the root length, bud length and chlorophyll content of seedlings could be affected by different degrees. The zinc fertilizer should be used in the production.

The effect of foliar treatment with brassinosteroid (BR) on gender distribution in flowers of walnut (Juglans regia L. cv. Chandler) was investigated. Grafted walnut saplings (‘Chandler’) on the wild walnut (Juglans regia L.) rootstock were planted into 70-liter pots with a soil: peat: perlite medium and grown in pots between 2016–2020. BRs (24-epibrassinolide; EBR and 22(S), 23(S)-homobrassinolide; HBR) were applied at a concentration of 1 mg L^–1 for four consecutive years at the time of flower differentiation. The experimental design was completely randomized with three replicates. The results show that BR applications could alter the sexual distribution of the walnut’s flower. BRs application significantly increased the number of total flowers and female flowers per tree. The number of female flowers was also increased by the season. The highest number of female flowers (20.9) was observed in the trees in 2020 and the application of 1 mg L^–1 of HBR. It was determined that the annual growth of the plant and the increase in the number of females and total flowers were positively related. The effect of BRs indicated that the response was BR-type specific.

Two kinds of solar thermal power generation systems (trough and tower) are selected as the research objects. The life cycle assessment (LCA) method is used to make a systematic and comprehensive environmental impact assessment on the trough and tower solar thermal power generation. This paper mainly analyzes the three stages of materials, production and transportation of two kinds of solar thermal power generation, calculates the unit energy consumption and environmental impact of the three stages respectively, and compares the analysis results of the two systems. At the same time, Rankine cycle is used to compare the thermal efficiency of the two systems.