Growth of covalent organic frameworks (COFs) as single crystals is extremely challenging. Inaccessibility of open‐structured single‐crystal COFs prevents the exploration of structure‐oriented applications. Herein we report for the first time a non‐interpenetrated single‐crystal COF, LZU‐306, which possesses the open structure constructed exclusively via covalent assembly. With a high void volume of 80 %, LZU‐306 was applied to investigate the intrinsic dynamics of reticulated tetraphenylethylene (TPE) as the individual aggregation‐induced‐emission moiety. Solid‐state 2H NMR investigation has determined that the rotation of benzene rings in TPE, being the freest among the reported cases, is as fast as 1.0×104 Hz at 203 K to 1.5×107 Hz at 293 K. This research not only explores a new paradigm for single‐crystal growth of open frameworks, but also provides a unique matrix‐isolation platform to reticulate functional moieties into a well‐defined and isolated state.

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Nowadays, with the green economy becoming mainstream in the world, an industrial revolution as the core of green development has emerged. Based on the empirical evidence from China's 30 provinces, this study establishes an evaluation index system of China's industrial green development and applies the analytic hierarchy process to determine the indices' weights and properties to measure the level of industrial green development in China's 30 provinces. Then, an empirical study is conducted to explore the relevant factors influencing China's industrial green development by using the dynamic panel data model and a panel threshold test. The results show that China's level of industrial green development has the characteristic of typical regional differentiation with a ladder-like distribution from the east and middle to the west, and the eastern region has the highest level on industrial green output, industrial green efficiency and industrial green innovation. Technological progress and innovation can stimulate industrial green development. The impact of environmental regulation and foreign investment on industrial green development presents a nonlinear "N"-type trend, and the positive effects are mainly observed in eastern China. Capital deepening, heavy chemical industries and an unreasonable energy structure are not effective in industrial green development. There is no direct relation between the enterprise scale and industrial green development.

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Agricultural land, as an important carbon source, has produced about 20% of carbon dioxide globally. The calculation and spatial-temporal distribution of carbon emissions resulting from agricultural land utilization (ALU) has attracted a great deal of attention from scholars. Most of the existing literature widely agrees that China's carbon emissions from ALU showed significant regional discrepancies, but rarely pays attention to the evolutionary characteristics of the discrepancies. This study calculated the total carbon emissions from ALU based on six kinds of carbon emissions sources in the 31 provinces of mainland China, which showed obviously different characteristics in terms of their abundances of agricultural land resources, relative scarcities of production factors, levels of science and technology and economic prosperity. We then analyzed the evolutionary process and characteristics of regional discrepancies in carbon emissions from ALU at the national level and regional level with the method of kernel density estimation. The key results demonstrated the following: (1) The carbon emissions from ALU in the whole country and the eastern, central and western regions of China have increased sharply during the study period. From 2000 to 2015, the carbon emissions from ALU in the whole of China, the eastern region, central region, and western region were increased by 2626.11 (10 4 tons), 441.32 (10 4 tons), 1054.45 (10 4 tons), and 1130.3 (10 4 tons), respectively, with an average annual growth rate of 2.75%, 1.29%, 3%, and 4.35%, respectively; (2) The scale of carbon emissions from ALU showed significant spatial disparities at the regional and inter-provincial levels. From 2000 to 2015, the central region had the highest carbon emissions from ALU, while the eastern and western regions had the second and third highest carbon emissions; (3) The distribution curves of carbon emissions from ALU in the whole country and each region all moved in the right direction gradually during the study period, and the width of the curves increased, indicating the regional discrepancies of carbon emissions from ALU was expanding at different spatial scales. Distribution curves of carbon emissions from ALU in the eastern, central and western regions all showed a "multi-polar" differentiation phenomenon in 2000, while presented a "tri-polar", "bipolar" and "multi-polar" division in 2015, respectively.

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