The effect of spraying bacterial and fungal solutions on Korean pine Pinus koraiensis Sieb. et Zucc. cone development and seed quality when sprayed during the flowering phase.

Korean pine is an economically essential afforestation species limited by the unreasonable collection of cones, indiscriminate use of chemical pesticides and pest damage. This study aimed to determine whether spraying bacterial or fungal solutions affected insect pests, cone development, and the seed quality of Korean pine Pinus koraiensis Sieb. et Zucc. The experiment was conducted in a forest plantation in Linkou County (Heilongjiang, China) in 2019. Four fungal strains and one bacterial strain were applied during the flowering phase of Korean pine. The results after a year and a half of study indicated that a high concentration of Bacillus thuringiensis 223176 promoted cone development, increased seed weight, and reduced the proportion of damaged cones. Under this treatment, there were 15.873% damaged cones; the seed weight reached 0.829 g, and there were 82.738% fully developed cones. Trees treated with the second most effective strain, Beauveria bassiana 122077, had 30.556% damaged cones and an average seed weight of 0.810 g. Leucanicillium antillanum 01 performed the worst in this study. The seed weight was only 0.775 g, and the damaged and fully developed cones were 52.444 and 41.773%, respectively. In summary, spraying bacterial or fungal solutions during the flowering stage of Korean pine positively impacted seed quality and effectively decreased damage by the lepidopteran species that feed on the cones and seeds in this study.

Enabling Semihydrogenation of Alkynes to Alkenes by Using a Calcium Palladium Complex Hydride.

Selective hydrogenation of alkynes to alkenes requires a catalytic site with suitable electronic properties for modulating the adsorption and conversion of alkyne, alkene as well as dihydrogen. Here, we report a complex palladium hydride, CaPdH2, featured by electron-rich [PdH2]δ- sites that are surrounded by Ca cations that interacts with C2H2 and C2H4 via σ-bonding to Pd and unusual cation-π interaction with Ca, resulting in a much weaker chemisorption than those of Pd metal catalysts. Concomitantly, the dissociation of H2 and hydrogenation of C2Hx (x = 2-4) species experience significant energy barriers over CaPdH2, which is fundamentally different from those reported Pd-based catalysts. Such a unique catalytic environment enables CaPdH2, the very first complex transition-metal hydride catalyst, to afford a high alkene selectivity for the semihydrogenation of alkynes.

Auto-classification of biomass through characterization of their pyrolysis behaviors using thermogravimetric analysis with support vector machine algorithm: case study for tobacco.

BACKGROUND: During the biomass-to-bio-oil conversion process, many studies focus on studying the association between biomass and bio-products using near-infrared spectra (NIR) and chemical analysis methods. However, the characterization of biomass pyrolysis behaviors using thermogravimetric analysis (TGA) with support vector machine (SVM) algorithm has not been reported. In this study, tobacco was chosen as the object for biomass, because the cigarette smoke (including water, tar, and gases) released by tobacco pyrolysis reactions decides the sensory quality, which is similar to biomass as a renewable resource through the pyrolysis process. RESULTS: SVM algorithm has been employed to automatically classify the planting area and growing position of tobacco leaves using thermogravimetric analysis data as the information source for the first time. Eighty-eight single-grade tobacco samples belonging to four grades and eight categories were split into the training, validation, and blind testing sets. Our model showed excellent performances in both the training and validation set as well as in the blind test, with accuracy over 91.67%. Throughout the whole dataset of 88 samples, our model not only provides precise results on the planting area of tobacco leave, but also accurately distinguishes the major grades among the upper, lower, and middle positions. The error only occurs in the classification of subgrades of the middle position. CONCLUSIONS: From the case study of tobacco, our results validated the feasibility of using TGA with SVM algorithm as an objective and fast method for auto-classification of tobacco planting area and growing position. In view of the high similarity between tobacco and other biomasses in the compositions and pyrolysis behaviors, this new protocol, which couples the TGA data with SVM algorithm, can potentially be extrapolated to the auto-classification of other biomass types.

Sodium anilinide-cyclohexylamide pair: synthesis, characterization, and hydrogen storage properties.

The lack of efficient hydrogen storage material is one of the bottlenecks for the large-scale implementation of hydrogen energy. Here, a series of new hydrogen storage materials, i.e., anilinide-cyclohexylamide pairs, are proposed via the metallation of an aniline-cyclohexylamine pair. DFT calculations show that the enthalpy change of hydrogen desorption (ΔHd) can be significantly tuned from 60.0 kJ per mol-H2 for the pristine aniline-cyclohexylamine pair to 42.2 kJ per mol-H2 for sodium anilinide-cyclohexylamide and 38.7 kJ per mol-H2 for potassium anilinide-cyclohexylamide, where an interesting correlation between the electronegativity of the metal and the ΔHd was observed. Experimentally, the sodium anilinide-cyclohexylamide pair was successfully synthesised with a theoretical hydrogen capacity of 4.9 wt%, and the hydrogenation and dehydrogenation cycle can be achieved at a relatively low temperature of 150 °C in the presence of commercial catalysts, in clear contrast to the pristine aniline-cyclohexylamine pair which undergoes dehydrogenation at elevated temperatures.

Metallo-N-Heterocycles - A new family of hydrogen storage material.

Storing hydrogen efficiently in condensed materials is a key technical challenge. Tremendous efforts have been given to inorganic hydrides containing B-H, Al-H and/or N-H bonds, while organic compounds with a great variety and rich chemistry in manipulating C-H and unsaturated bonds, however, are undervalued mainly because of their unfavourable thermodynamics and selectivity in dehydrogenation. Here, we developed a new family of hydrogen storage material spanning across the domain of inorganic and organic hydrogenous compounds, namely metallo-N-heterocycles, utilizing the electron donating nature of alkali or alkaline earth metals to tune the electron densities of N-heterocyclic molecules to be suitable for hydrogen storage in terms of thermodynamic properties. Theoretical calculations reveal that the enthalpies of dehydrogenation (ΔHd) of these metallo-N-heterocycles are dependent on the electronegativity of the metals. In line with our calculation results, sodium and lithium analogues of pyrrolides, imidazolides and carbazolides of distinct structures were synthesized and characterized for the first time, where the cation-π interaction was identified. More importantly, a reversible hydrogen absorption and desorption can be achieved over lithium carbazolide which has a hydrogen capacity as high as 6.5 wt% and a suitable enthalpy of dehydrogenation of 34.2 kJ mol-1-H2 for on-board hydrogen storage.