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Many macrocyclic compounds are attractive drug‐like molecules or intermediates due to their special properties. However, the bulk synthesis of such compounds are hindered by the necessity of using diluted solutions, in order to prevent intermolecular reactions that yields oligomer impurities, thereby resulting in a low production efficiency. Such challenge can be adequately addressed by using continuous reactors, allowing improved efficiency with smaller space footprints. In this work, we proposed a novel continuous process for the synthesis of a macrocyclic sulfite of tetraethylene glycol (PEG4‐MCSi), which is a precursor to a very useful building block, PEG4‐macrocyclic sulfate (PEG4‐MCS). The basic reaction parameters, including stoichiometry and temperature, were first confirmed with small batch reactions, and the effectiveness of coiled reactors and continuous stirred tank reactors (CSTRs) were compared. Cascaded CSTRs were proven to be suitable, and the reaction parameters were subject to further optimization to give a robust continuous process. The process was then tested with 4 parallel runs for up to 64 h. Finally, the merits and demerits of batch and continuous reactions were also compared, demonstrating the suitability of latter in the bulk production of macrocyclic PEG‐MCSi compounds. [ABSTRACT FROM AUTHOR]

Subalpine peat wetlands are extremely sensitive to global environmental changes and anthropogenic disturbances. Unlike most other biological groups, plant species can possess dormant life‐history stages such as the soil seed bank (SSB), which may help plant communities to resist or at least postpone the detrimental impact of disturbance. This study investigates the potential for SSB to achieve this along a soil moisture gradient. Species richness and density of SSB were significantly lower by 31.9% and 47.2% in wetland, and 35.1% and 68.1% in swamp meadow in comparison with steppe meadow, respectively. Soil moisture content did not directly affect the density and species richness of SSB, whilst had indirect effects on density and species richness via affecting vegetation and soil pH. SSB composition was less responsive to soil moisture changes than plant community composition. Furthermore, compositional trends in the annual plant SSB were weaker than in the aboveground vegetation along the soil moisture gradient. The similarity between SSB and vegetation significantly declined with increasing soil moisture content. High SSB diversity and compositional similarity between the vegetation and SSB may provide a potentially important functional buffer against the impact of ongoing moisture changes on plant communities in wetlands. Dormant life‐history stages can therefore be important sources of diversity in changing environments. Furthermore, although SSB has low regeneration potential for the aboveground vegetation communities in subalpine peat wetlands, the SSB would still not be a neglected factor for the restoration of propagule diversity after disturbance in wetlands if hydrology is restored. [ABSTRACT FROM AUTHOR]

The detailed chemical reaction mechanism of high temperature pyrolysis is constructed through the comparison of various current reaction mechanisms and sub‐models. This mechanism can better predict the formation of polycyclic aromatic hydrocarbons. Through path analysis, the interrelationship of the growth mechanisms of polycyclic aromatic hydrocarbons is expounded. And the important contribution pathways of five‐membered/six‐membered rings at high temperatures are investigated. Through component flux analysis and sensitivity analysis, the results show that the main formation path of the external five‐membered ring is the acetylene addition of naphthalene. Its stability decreases with increasing temperature and is the main introduction route of molecular curvature during low temperature pyrolysis. However, the embedded five‐membered ring obtained by benzene cycloaddition is less affected by temperature and is the most important chemical reaction process introduced by high temperature molecular curvature. The hydrogen abstraction acetylene addition mechanism still plays a dominant role at different temperatures and is a classical pathway for the formation of six‐membered rings. By cooperating with multiple reaction mechanisms, the formation mechanism of polycyclic aromatic hydrocarbons at different temperatures can be well predicted. [ABSTRACT FROM AUTHOR]

This article discusses a novel continuous process for synthesizing a macrocyclic sulfite of tetra(ethylene glycol), which is a precursor to a useful building block called PEG4-macrocyclic sulfate. The process involves using a set of cascaded continuously stirred tank reactors to contain the reaction mixtures. The core features of this process are outlined in the article, and more information can be found in the research article by L. Pan and co-workers. [Extracted from the article]

The problem of poor compatibility between organic functional molecules and waterborne polyurethane systems has received widespread attention. Herein, in order to reduce the effect of spirooxazine introduction on the compatibility of polyurethane in aqueous systems, two novel spirooxazine compounds SO2 and SO4 with hydrophilic groups were synthesized and successfully introduced into waterborne polyurethanes by chemical bonding and physical blending. The results show that compared with pure waterborne polyurethane, the particle size of the waterborne polyurethane emulsion bonded with SO2 or SO4 (0.5 wt%) is significantly reduced, and the SO4 effect is more obvious. Therefore, SO20.5‐WPU (grafted with 0.5 wt% SO2) and SO40.5‐WPU (grafted with 0.5 wt% SO4) have more uniform film formation and higher light transmittance. Additionally, the physical blending of SO2 and SO4 has less impact on the mechanical properties and water resistance of the films compared to chemical grafting. Tensile strength was able to maintain 72.3% and 88.5%, and water resistance remained 77.5% and 68.5%, respectively. The films prepared by the two methods have good photochromic performance and fatigue resistance, but the spirooxazine in the chemically bonded film has better thermal stability. Therefore, we provide a new idea for the preparation of functional aqueous polyurethane. [ABSTRACT FROM AUTHOR]

Using an inexpensive and eco‐friendly wood substrate, herein, a one‐step calcination method is developed to deposit Co‐Ni binary nanoparticles into aligned wood channels and an effective carbonized wood (CW) electrode (termed as Co/Ni‐CW) is fabricated. Well distributed Co‐Ni nanoparticles are achieved by the coordination bonds between the hydroxyl groups on wood matrix and soaked metal cations. Subsequently, high‐temperature calcination promotes the nucleation of Co‐Ni nanoparticles and the formation of CW. With the uniform distribution of Co‐Ni nanoparticles and porous wood structure, not only is a high active surface area, but also the electron and mass diffusion pathways are enhanced. Thus, the as‐prepared Co/Ni‐CW affords the current density of 10 mA cm–2 at low overpotentials of 330 and 157 mV for oxygen and hydrogen evolution, respectively. Remarkably, when the wood‐based bifunctional electrocatalyst is used as both the anode and cathode, a low cell voltage of 1.64 V is required to reach the current density of 10 mA cm–2. Compared with most substrates used in bifunctional electrocatalysts, the abundance, low cost, eco‐friendliness, and easy operation of wood‐based catalysts allow for an active and scalable electrode for water splitting and many other energy storage devices. [ABSTRACT FROM AUTHOR]