All-inorganic lead halide perovskite nanocrystals (NCs) are potential candidates for fabricating high-performance light-emitting diodes (LEDs) owing to their precisely tunable bandgaps, high photoluminescence (PL) efficiency, and excellent color purities. However, the performance of pure red (630−640 nm) all-inorganic perovskite LEDs is still limited by the halide segregation-induced instability of the electroluminescence (EL) of mixed halide CsPbI 3-x Br x NCs. Herein, we report an effective approach to improving the EL stability of pure red all-inorganic CsPbI 3-x Br x NC-based LEDs via the passivation of potassium bromide on NCs. By adding potassium oleate to the reaction system, we obtained potassium bromide surfacepassivated (KBr-passivated) CsPbI 3-x Br x NCs with pure red PL emission and a photoluminescence quantum yield (PLQY) exceeding 90%. We determine that most potassium ions present on the surface of NCs bind with bromide ions and thus demonstrate that potassium bromide surface passivation of NCs can both improve the PL stability and inhibit the halide segregation of NCs. Using KBr-passivated CsPbI 3-x Br x NCs as an emitting layer, we fabricated stable and pure red perovskite LEDs with emission at 637 nm, showing a maximum brightness of 2671 cd m −2 , maximum external quantum efficiency of 3.55%, and good EL stability. The proposed KBrpassivated NC strategy will open a new avenue for fabricating efficient, stable, and tunable pure color perovskite NC LEDs.

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The nomadic pastoral indigenous communities of the Ladakhi people share roots with Tibetan culture in terms of food, clothing, religion, festivals, and habits, and rely widely on plant resources for survival and livelihood. This survey was conducted during 2019–2021 to document the indigenous knowledge about plant resources of the Balti, Beda, and Brokpa communities of the Ladakh region, trans-Himalayas. Open- and close-ended semi-structured interviews (N = 184) and group discussions (N = 17) were used to collect the data. Quantitative data was further analyzed using various statistical tools. A total of 105 plant species belonging to 82 genera and 39 families were used as medicine, fuel wood, fragrance, oil, food, flavor, fodder, decoration, and dye. Among these, medicinal use was most prevalent, with 70% of use reports, followed by fodder and fuel wood. Leaves (27%) were the most preferred plant part used, followed by roots and flowers. The principal component analysis revealed five clusters of ethnobotanical usage, i.e., food, medicine, fuel wood, fodder, and fragrance, oil, dye, and flavor. The maximum number of plant species used was reported by the Brokpa, while the Beda reported the minimum number of plant species uses. Delphinium brunonianum, Waldheimia tomentosa, and Juniperus indica played a significant role in the cultural and religious ritual aspects, whereas Allium przewalskianum, Waldheimia tomentosa, Juniperus indica, and Hippophae rhamnoides were commonly used as a livelihood source among Ladakhi communities. The local people collected most plants (65%) for self-consumption, while the rest (35%) were sold in markets as a source of income. The sustainable utilization and management of plant resources by local people is a strategy to boost livelihoods and food security and alleviate poverty.

Various cognitive aids (such as change of color, arrows, etc.) are provided in virtual environments to assist users in task realization. These aids increase users' performance but lead to reduced learning because there is less cognitive load on the users. In this paper we present a new concept of procedural guidance in which textual information regarding the procedure of a task is provided to users. The users convert this information into physical actions to complete the task, which enhances their learning by creating a consolidated mental model. We use Multimodal Virtual Chemistry Laboratory, where students simulate a chemistry experiment with the help of procedural guidance. Evaluations reveal that the proposed guidance enhances students' learning and consequently increases their performance in real-world situations.