Graphene, an innovative nanocarbon, has been discovered as a significant technological material. Increasing utilization of graphene has moved research towards the development of sustainable green techniques to synthesize graphene and related nanomaterials. This review article is basically designed to highlight the significant sustainability aspects of graphene. Consequently, the sustainability vision is presented for graphene and graphene nanocomposites. Environmentally sustainable production of graphene and ensuing nanomaterials has been studied. The formation of graphene, graphene oxide, reduced graphene oxide, and other derivatives has been synthesized using ecological carbon and green sources, green solvents, non-toxic reagents, and green routes. Furthermore, the utilization of graphene for the conversion of industrial polymers to sustainable recycled polymers has been studied. In addition, the recycled polymers have also been used to form graphene as a sustainable method. The implication of graphene in the sustainable energy systems has been investigated. Specifically, high specific capacitance and capacitance retention were observed for graphene-based supercapacitor systems. Subsequently, graphene may act as a multi-functional, high performance, green nanomaterial with low weight, low price, and environmental friendliness for sustainable engineering and green energy storage applications. However, existing challenges regarding advanced material design, processing, recyclability, and commercial scale production need to be overcome to unveil the true sustainability aspects of graphene in the environmental and energy sectors.

Given the growing significance of the metaverse in research, it is crucial to understand its scope, relevance in the tourism industry, and the human-computer interaction it involves. The emerging field of metaverse tourism has a noticeable research gap, limiting a comprehensive understanding of the concept. This article addresses this gap by conducting a hybrid systematic review, including a variable-oriented literature review, to assess the extent and scope of metaverse tourism. A scrutiny on Scopus identified a reduced number of relevant documents. The analysis exposes theoretical and empirical gaps, along with promising opportunities in the metaverse and tourism intersection. These insights contribute to shaping a contemporary research agenda, emphasizing metaverse tourism. While this study offers an overview of current research in metaverse tourism, it is essential to recognize that this field is still in its early stages, marked by the convergence of technology and transformations in tourism. This exploration underscores the challenges and opportunities arising from the evolving narrative of metaverse tourism.

This paper provides a comprehensive review of equity trading simulators, focusing on their performance in assuring pre-trade compliance and portfolio investment management. A systematic search was conducted that covered the period of January 2000 to May 2023 and used keywords related to equity trade simulators, portfolio management, pre-trade compliance, online trading, and artificial intelligence. Studies demonstrating the use of simulators and online platforms specific to portfolio investment management, written in English, and matching the specified query were included. Abstracts, commentaries, editorials, and studies unrelated to finance and investments were excluded. The data extraction process included data related to challenges in modern portfolio trading, online stock trading strategies, the utilization of deep learning, the features of equity trade simulators, and examples of equity trade simulators. A total of 32 studies were included in the systematic review and were approved for qualitative analysis. The challenges identified for portfolio trading included the subjective nature of the inputs, variations in the return distributions, the complexity of blending different investments, considerations of liquidity, trading illiquid securities, optimal portfolio execution, clustering and classification, the handling of special trading days, the real-time pricing of derivatives, and transaction cost models (TCMs). Portfolio optimization techniques have evolved to maximize portfolio returns and minimize risk through optimal asset allocation. Equity trade simulators have become vital tools for portfolio managers, enabling them to assess investment strategies, ensure pre-trade compliance, and mitigate risks. Through simulations, portfolio managers can test investment scenarios, identify potential hazards, and improve their decision-making process.

Objective: To study the changes of growth, physiological and absorption characteristics of Pinus bungeana under ozone (O₃) stress, to elucidate the correlations among the indicators, and to determine its degree of response to O₃. Methods: The growth, physiological characteristics and O₃ uptake capacity of Pinus bungeana seedlings were measured in an open-top O₃ fumigation manual control experiment with three concentration gradients (NF: normal atmospheric O₃ concentration, NF40: normal atmospheric O₃ concentration plus 40 nmlol/mol; NF80: normal atmospheric O₃ concentration plus 80 nmol/mol), and the relationships between the characteristics of Pinus bungeana under different O₃ concentrations were investigated with correlation analysis, redundancy analysis and analysis of variance. Results: (1) Plant height growth (ΔH), diameter growth at 50 cm (ΔDBH), stomatal size (S), stomatal density (M), stomatal opening (K), stomatal conductance (G_s), net photosynthetic rate (P_n), transpiration rate (E_t), water use efficiency (WUE), maximum photochemical efficiency (F_v/F_m), chlorophyll content (CHL), whole tree water consumption (W), and O₃ uptake rate () all decreased with the increase of O₃ concentration; while intercellular CO₂ concentration () and relative conductivity (L) increased with the increase of O₃ concentration; (2) growth indicators of Pinus bungeana under O₃ stress (ΔH, ΔDBH) were the most correlated with O₃ uptake status (, W), followed by photosynthetic indicators (, WUE, ,, ) and growth indicators (ΔH, ΔDBH) and stomatal characteristics (K, M, S) under O₃ stress, some physiological indicators (L, ) were relatively weakly correlated with photosynthesis (, WUE,,, ) and stomatal (K, M, S); (3) all the indicators of Pinus bungeana were significantly different under O₃ treatments of NF and NF80 (P < 0.05), ΔH, ΔDBH, M, CHL, , , W and were most significantly different under NF and NF40 treatments, and K, S, WUE, , , , L were more significantly different under NF40 and NF80 treatments. Conclusion: The experiment proved that the growth of Pinus bungeana was slowed, photosynthetic capacity was reduced, and the absorption capacity of O₃ was further reduced by long-term exposure to high concentration of O₃. The growth of Pinus bungeana was most correlated with the changes of O₃ absorption characteristics, and the stomatal characteristics were most correlated with photosynthetic physiological characteristics, and the reduction of photosynthetic capacity etc. further led to the curtailment of its growth.