Modern large wind farms are required to provide frequency regulation service like conventional synchronous generation units. The frequency support capability of modern wind farms has been widely ...investigated and implemented. Remotely located large offshore wind farms are probably connected to the onshore system grid through voltage-source converter-based-high voltage direct current (VSC-HVdc) transmission systems. Due to the decoupling of VSC-HVdc and signal transmission delay, offshore wind farms may not be able to respond to the onshore grid frequency excursion in time and, consequently, the stability and security of the power system will be put at risk, especially for those with high wind penetration. This paper proposes a coordinated control scheme to allow VSC-HVdc link to contribute to the system frequency regulation by adjusting its dc-link voltage. By means of this approach, the dc capacitors of VSC-HVdc are controlled to absorb or release energy so as to provide frequency support. To further enhance the system frequency response, the frequency support from VSC-HVdc is also finely coordinated with that from offshore wind farm according to the latency of offshore wind farm responding to onshore grid frequency excursion. The control scheme is evaluated for both underfrequency and overfrequency events, and results are presented to demonstrate its effectiveness.
Renewable poly(lactic acid) (PLA) exhibits high strength and stiffness. PLA is fully biodegradable and has received great interest. However, the inherent brittleness of PLA largely impedes its wide ...applications. In this article, the recent progress in PLA toughening using various routes including plasticization, copolymerization, and melt blending with flexible polymers, was reviewed in detail. PLA toughening, particularly modification of impact toughness through melt blending, was emphasized in this review. Reactive blending was shown to be especially effective in achieving high impact strength. The relationship between composition, morphology, and mechanical properties were summarized. Toughening mechanisms were also discussed.
A novel ferrocene‐linked organic–inorganic hybrid porous polymer has been successfully prepared by Friedel–Crafts reaction of octavinylsilsesquioxane and ferrocene. The relationship of ...structure/property was investigated by FTIR, NMR, XRD, Brunauer–Emmett–Teller (BET) etc. The obtained porous polymer exhibited a high surface area of 1015 m2 g−1 and a hierarchical pore structure. It could be applied to wastewater treatment with the absorption capacity of up to 1683 mg g−1 for Congo red (CR), 1083 mg g−1 for crystal violet (CV), 1003 mg g−1 for rhodamine B (RB), 441 mg g−1 for methylene blue (MB), 191 mg g−1 for Hg2+, and 328 mg g−1 for Pb2+. Remarkably, it could be easily regenerated and the removal efficiency remains almost constant even after six cycles.
Hybrid porous polymers: A novel ferrocene‐functionalized silsesquioxane‐based porous polymer was successfully prepared by Friedel–Crafts reaction of octavinylsilsesquioxane with ferrocene. It can be applied to wastewater treatment and easily regenerated.
β-glucan is a non-starch soluble polysaccharide widely present in yeast, mushrooms, bacteria, algae, barley, and oat. β-Glucan is regarded as a functional food ingredient due to its various health ...benefits. The high molecular weight (Mw) and high viscosity of β-glucan are responsible for its hypocholesterolemic and hypoglycemic properties. Thus, β-glucan is also used in the food industry for the production of functional food products. The inherent gel-forming property and high viscosity of β-glucan lead to the production of low-fat foods with improved textural properties. Various studies have reported the relationship between the molecular structure of β-glucan and its functionality. The structural characteristics of β-glucan, including specific glycosidic linkages, monosaccharide compositions, Mw, and chain conformation, were reported to affect its physiochemical and biological properties. Researchers have also reported some chemical, physical, and enzymatic treatments can successfully alter the molecular structure and functionalities of β-glucan. This review article attempts to review the available literature on the relationship of the molecular structure of β-glucan with its functionalities, and future perspectives in this area.
Colorectal cancer (CRC) is among the most common malignancies with limited treatments other than surgery. The tumor microenvironment (TME) profiling enables the discovery of potential therapeutic ...targets. Here, we profile 54,103 cells from tumor and adjacent tissues to characterize cellular composition and elucidate the potential origin and regulation of tumor-enriched cell types in CRC. We demonstrate that the tumor-specific FAP
fibroblasts and SPP1
macrophages were positively correlated in 14 independent CRC cohorts containing 2550 samples and validate their close localization by immuno-fluorescent staining and spatial transcriptomics. This interaction might be regulated by chemerin, TGF-β, and interleukin-1, which would stimulate the formation of immune-excluded desmoplasic structure and limit the T cell infiltration. Furthermore, we find patients with high FAP or SPP1 expression achieved less therapeutic benefit from an anti-PD-L1 therapy cohort. Our results provide a potential therapeutic strategy by disrupting FAP
fibroblasts and SPP1
macrophages interaction to improve immunotherapy.
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•A silsesquioxane-based disulfide-linked polymer was rapidly synthesized in 2 min.•The polymer shows a highly selective and efficient adsorption towards cationic dyes over anionic ...dyes.•The absorbent is recyclable.
Developing a facile and rapid method to prepare adsorbents for an efficient and selective removal of dyes is of great importance for human health and environment. In this work, a silsesquioxane-based disulfide-linked polymer (DLP) was rapidly synthesized by a simple oxidative coupling reaction of octa(3-mercaptopropyl)silsesquioxane within 2 min at room temperature. The synthesized DLP demonstrated selective and efficient adsorption of cationic dyes over anionic dyes with the maximum capacities of 12.94 mg g−1 for methylene blue, 18.47 mg g−1 for rhodamine B and 26.69 mg g−1 for crystal violet. The high uptake and selectivity for cationic dyes was attributed to the electrostatic interactions between the anionic charges from sulfur and oxygen anions formed by the deprotonation of thiols and hydroxyls in the DLP and the cationic charges from the dyes, and the swelling behavior of the DLP. To investigate the adsorption process, the effect of various factors such as contact time, initial concentration, temperature, and pH on the adsorption activity of cationic dyes was studied. The adsorption equilibrium data showed a better fitting to the Langmuir isotherm model than the Freundlich model and the adsorption kinetics fitted well with the pseudo-second-order kinetic model, indicating that the adsorption process is mostly governed by the chemisorption behavior. Additionally, the absorbent was recyclable with the adsorption capacity being >95% after five times recycle adsorption. These results indicated that the present disulfide-linked polymer could be promisingly applied as an efficient adsorbent for the selective removal of cationic dyes from industrial wastewater.
Three new hybrid ionic liquids (ILs) based on cage silsesquioxane (SQ) were rapidly prepared in high yields from octa(mercaptopropyl)silsesquioxane and 1‐allyl‐3‐methylimidazolium salts (Br−, BF4−, ...PF6−) through the photochemical thiol–ene reaction. These SQ‐based ILs exhibited low glass transition temperatures and good thermal stability. The unique amphiphilic nature of these hybrid ILs cause them to self‐assemble into perfect vesicles with “yolk–shell” structures, in which cages formed the “yolk” due to their aggregation and outer anions formed the “shell”.
The SQ‐ILs to pay the bills: Three novel hybrid ionic liquids based on cage silsesquioxane (SQ) were rapidly prepared in high yields by the photochemical thiol–ene reaction. They could further self‐assemble into perfect vesicles with “yolk–shell” structures. These SQ‐based ILs exhibited low glass transition temperatures and good thermal stability.
Two series of new polyhedral oligomeric silsesquioxane (POSS)‐based fluorescent hybrid porous polymers, HPP‐1 and HPP‐2, have been prepared by the Heck reaction of octavinylsilsesquioxane with ...2,2′,7,7′‐tetrabromo‐9,9′‐spirobifluorene and 1,3,6,8‐tetrabromopyrene, respectively. Three sets of reaction conditions were employed to assess their effect on fluorescence. These materials exhibit tunable fluorescence from nearly no fluorescence to bright fluorescence both in the solid state and dispersed in ethanol under UV light irradiation by simply altering the reaction conditions. We speculated that the difference may be attributable to the fluorescence quenching induced by Et3N, P(o‐CH3Ph)3, and their hydrogen bromide salts employed in the reactions. This finding could give valuable suggestions for the construction of porous polymers with tunable/controllable fluorescence, especially those prepared by Heck and Sonogashira reactions in which these quenchers are used as organic bases or co‐catalysts. In addition, the porosities can also be tuned, but different trends in porosity have been found in these two series of polymers, which suggests that various factors should be carefully considered in the preparation of porous polymers with tunable/controllable porosity. Furthermore, HPP‐1 c showed moderate CO2 uptake and fluorescence that was efficiently quenched by nitroaromatic explosives, thereby indicating that these materials could be utilized as solid absorbents for the capture and storage of CO2 and as sensing agents for the detection of explosives.
Tunable fluorescence: Fluorescent porous polymers have been obtained by the Heck reaction of octavinylsilsesquioxane with brominated aromatic monomers. The polymers exhibit tunable fluorescence from nearly no fluorescence to bright fluorescence by simply altering the reaction conditions (see figure). This finding could give valuable suggestions for the construction of porous polymers with tunable/controllable fluorescence.
This study aims to investigate the electrochemical properties of lead calcium tin (Pb–Ca(0.14%)–Sn(1.04%)) anode employed in hydrometallurgy. Various methods were employed, including cyclic ...voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS), to comprehensively characterize the behavior of this alloy under diverse operating conditions. The findings of this investigation indicate that the Pb–Ca(0.14%)–Sn(1.04%) anode demonstrates remarkable corrosion resistance and a lower oxygen evolution potential in comparison to conventional lead anodes. As a result, enhanced operational efficiency can be achieved. Furthermore, the incorporation of Ca and Sn in the alloy has a substantial positive effect on its mechanical properties, thereby rendering the anode more resilient in harsh operating environments. Consequently, this contributes to reduced maintenance costs. Overall, this study underscores the promising potential of lead calcium tin anodes in promoting more sustainable and efficient hydrometallurgical processes.
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