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The red imported fire ant, Solenopsis invicta Buren, poses a significant threat to biodiversity, agriculture, and public health in its introduced ranges. While chemicals such as toxic baits and dust are the main methods for S. invicta control, toxic baits are slow, requiring approximately one or two weeks, but dust can eliminate the colony of fire ants rapidly in just three to five days. To explore more active ingredients for fire ant control using dusts, the toxicity of bifenthrin and dimefluthrin, the horizontal transfer of bifenthrin and dimefluthrin dust and their efficacy in the field were tested. The results showed that the LD50 (lethal dose) values of bifenthrin and dimefluthrin were 3.40 and 1.57 ng/ant, respectively. The KT50 (median knockdown time) and KT95 (95% knockdown time) values of a 20 μg mL–1 bifenthrin dose were 7.179 and 16.611 min, respectively. The KT50 and KT95 of a 5 μg mL–1 dimefluthrin dose were 1.538 and 2.825 min, respectively. The horizontal transfers of bifenthrin and dimefluthrin among workers were effective. The mortality of recipients (secondary mortality) and secondary recipients (tertiary mortality) were both over 80% at 48 h after 0.25, 0.50 and 1.00% bifenthrin dust treatments. The secondary mortality of recipients was over 99% at 48 h after 0.25, 0.50 and 1.00% dimefluthrin dust treatments, but the tertiary mortality was below 20%. The field trial results showed that both bifenthrin and dimefluthrin exhibited excellent fire ant control effects, and the comprehensive control effects of 1.00% bifenthrin and dimefluthrin dusts at 14 d post-treatment were 95.87 and 85.70%, respectively.

2H‐arizines are important three‐membered heterocycles in organic chemistry. Recently, many advances in the synthesis and functionalization of 2H‐arizines have been reported. Neber rearrangement, isomerization of isoxazole, oxidation of enamine, C−H bond activation, decomposition of vinyl azide, functionalization of alkyne, and multi‐step synthesis have been developed for the efficient assembly of 2H‐azirines. As versatile and highly strained three‐membered unsaturated heterocycles, 2H‐azirines can be used as distinctive building blocks towards significant functional groups, and have attracted extensive attention for the fabrication of numerous heterocycles. Recent studies have focused on [3+n] ring‐expansion reactions, nucleophilic addition of C=N double bond or continuous nucleophilic addition followed by cyclization, ring‐opening of 2H‐azirines to acyclic compounds, and substitution of sp3‐C−H of 2H‐azirines. One of the most critical challenges is seeking for a selective opening of the specific three bonds of the strained azirine circle, some of what can be achieved on the basis of metal catalyst, photocatalysis, or combination of metal catalyst and photocatalysis. In this review, recent advances involving the synthesis and reactivity of 2H‐arizines accompanied with challenges and breakthroughs are summarized. The review mainly covers the period from 2019 to 2023. [ABSTRACT FROM AUTHOR]

Celery (Apium graveolens L.) is a kind of green leaf vegetable with a large consumption demand in the food industry. It is a commonly used material in quick-frozen food stuffing such as dumplings and steamed stuffed. Fresh celery leaf blades and petioles are rich in photosynthetic pigments including chlorophyll and carotenoid, their contents are closely related to the quality of celery and its products. In order to explore the effects of freezing and thawing temperature and thawing time on the degradation of photosynthetic pigments in celery leaf blades and petioles, the changes in photosynthetic pigments during thawing storage were measured under different freezing and thawing temperatures. The results showed that lower freezing and thawing temperatures were beneficial to the preservation of photosynthetic pigments in celery leaf blades and petioles, and the loss of photosynthetic pigments enhanced with the increase in thawing temperature and thawing time. Under the cold storage condition of −80 °C, the loss rate of pigment substances can be reduced by nearly 20% compared with that of −18 °C, and −80 °C and 4 °C could be the best temperature combination of freezing and thawing. The content and degradation rate of photosynthetic pigments in celery leaf blades were higher than that in petioles during thawing, with a total chlorophyll loss rate reaching 35% during 6 to 12 h after thawing. The increase in temperature difference between freezing and thawing could aggravate the damage to the cell structure and the degradation of the pigment, as chlorophyll is more sensitive to temperature changes, and the degradation rate is significantly higher than that of carotenoids. From the perspective of delaying the degradation of photosynthetic pigments, the results of this study will provide potential references for the reasonable configuration of freezing and thawing temperatures in the process of storage and transportation of celery products. [ABSTRACT FROM AUTHOR]

The electrical properties and band offset of ZnS/ n-Si(111) heterojunctions with and without annealing were analyzed. The result showed that the rectifying characteristics of ZnS/ n-Si(111) heterojunctions became better and the leakage current increased after annealing. This phenomenon is mostly due to the volatilization of S atoms of ZnS films and leads to defect levels appearing at the interface of the ZnS/ n-Si(111) hetrojunctions. The valence band offset (Δ E ) of the ZnS/ n-Si(111) heterojunctions can be calculated to be −0.7 ± 0.15 eV by means of photoelectron spectroscopy, indicating that the band offsets of ZnS/ n-Si(111) heterojunctions show a type-II band alignment. [ABSTRACT FROM AUTHOR]