Toroidal nanostructures are symmetrical ring-shaped structures with a central internal pore. Interestingly, in nature, many transmembrane proteins such as β-barrels and α-helical bundles have toroidal shapes. Because of this similarity, toroidal nanostructures can provide a template for the development of transmembrane channels. However, because of the lack of guiding principles for the construction of toroids, researchers have not widely studied the self-assembly of toroidal nanostructures as compared with the work on other supramolecular architectures. In this Account, we describe our recent efforts to construct toroidal nanostructures through the self-assembly of rationally designed building blocks. In one strategy for building these structures, we induce interfacial curvatures within the building blocks. When we laterally graft a bulky hydrophilic segment onto a p-oligophenyl rod or β-sheet peptides, the backbones of the self-assembled structures can bend in response to the steric effect of these large side groups, driving the p-oligophenyl rod or β-sheet peptides to form nanosized toriods. In another strategy, we can build toroids from bent-shaped building blocks by stacking the macrocycles. Aromatic segments with an internal angle of 120° can associate with each other in aqueous solution to form a hexameric macrocycle. Then these macrocycles can stack on top of each other via hydrophobic and π-π interactions and form highly uniform toroidal nanostructures. We provide many examples that illustrate these guiding principles for constructing toroidal nanostructures in aqueous solution. Efforts to create toroidal nanostructures through the self-assembly of elaborately designed molecular modules provide a fundamental approach toward the development of artificial transmembrane channels. Among the various toroids that we developed, a few nanostructures can insert into lipid membranes and allow limited transport in vesicles.
The “Quantitative Assessment of Radiation Belt Modeling” focus group was in place at Geospace Environment Modeling from 2014 to 2018. The overarching goals of this focus group were to bring together the current state‐of‐the‐art models for the acceleration, transport, and loss processes in Earth's radiation belts; develop event‐specific and global inputs of wave, plasma, and magnetic field to drive these models; and combine all these components to achieve a quantitative assessment of radiation belt modeling by validating against contemporary radiation belt measurements. This article briefly reviews the current understanding of radiation belt dynamics and related modeling efforts, summarizes the activities and accomplishments of the focus group, and discusses future directions.
The aim of the construction of Northeast Tiger-Leopard National Park is to protect the integrity of endangered wild animals and natural resources. There is a close relationship between land use and ecosystem service value. Improving the quality of ecological environment is the demand of ecological civilization construction. Therefore, this paper aims to evaluate and analyze the ecosystem service value of Tiger and Leopard Park, which is particularly based on big data land use change. Firstly, using ArcGIS software as the support, we have discussed the impact of the dynamic trend of land use change, transfer matrix, and sensitivity coefficient on ecosystem services in different periods of Tiger and Leopard Park. Secondly, we constructed an evaluation model based on the ecological service value method, which is primarily based on geographical conditions and surface coverage. We have completed the value evaluation and change analysis of ecosystem service in Tiger and Leopard Park by analyzing the generation process of ecosystem service data and information characteristics, as well as the ecosystem classification standard of Tiger and Leopard Park and equivalent factor of ecosystem service value per unit area. Simulation experiments show that the method proposed in this paper can reflect the service value of the ecosystem of the Tiger and Leopard Park, lay the foundation for the construction of ecotourism, and promote the green and sustainable development of the regional ecosystem of the Tiger and Leopard Park.
The garden landscape of urban residential areas has significant environmental benefits, allowing people to get closer to nature and integrate with nature to relax and have some social benefits at the same time. This article is aimed at studying the effect of urban greening remote sensing on residential landscape construction. This paper uses the greening remote sensing image processing algorithm combined with the analysis method of SURF color remote sensing image and conducts the experiment based on the urban greening remote sensing on the residential area landscape architecture research. This article combines sustainable development strategies with innovative design methods to deeply study the role of urban greening remote sensing on the construction of residential landscape architecture. At the same time, the experiment in this article also proposes that the garden landscape of urban residential areas can provide entertainment for people, soothe residents’ mood, and achieve the best use of residential buildings. However, there are still some constraints in the development process of residential industry: insufficient government support, relatively backward technology of residential industrialization, lack of support and input from enterprises, and prejudice of people’s traditional concept towards it. The experimental results of this paper show that the remote sensing image features of buildings in residential areas and public areas are obvious. In the recognition of 46 training features and 34 detection features, the number of correct remote sensing recognition features is 32, and the green building image remote sensing recognition is good. The accuracy is 94%, which can meet the identification requirements of greening in the building. Combined with the specific conditions of urban greening and garden construction in my country, it can meet people’s entertainment needs and, to a certain extent, can also improve people’s life and cultural taste.
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