Recent realization of high sodium‐ion conductivities (>10−2 S cm−1) in inorganic solid electrolytes (ISEs) at room temperature will certainly trigger a boom in all‐solid‐state sodium batteries ...(ASS‐SBs). However, their electrochemical stable windows and compatibility to high capacity/voltage electrodes are unsatisfactory. Developing ideal ISEs that deliver high Na+ ion conductivities, good electrochemical/chemical stability, and compatible electrode/ISE interface is key for the success of high‐performance ASS‐SBs. In this review, focus is mainly on the fundamentals and strategies to optimize ASS‐SB performances from the aspects of ISE and interface, and note that interfacial issues are also ISE‐related. The latest progress in ISEs, including fundamentals of the sodium‐ion conduction mechanism, key parameters dominating the Na+ ion conduction in terms of crystal structure, lattice dynamics, point defects, and grain boundaries, and prototyping strategies for cell design, are elaborated from the perspectives of material and defect chemistry. The key challenges and future opportunities are discussed, and rational solutions are provided.
This review discusses the fundamentals of sodium ionic conduction in inorganic solid electrolytes (ISEs), identifies the key parameters dominating the sodium ionic conduction, and proposes prototyping strategies for both solid electrolyte and full cell design, from the perspectives of materials and defect chemistry. The key challenges and future opportunities for all‐solid‐state sodium batteries using ISEs are also discussed in detail.
An efficient and selective Cu catalyst for CO2 electroreduction is highly desirable since current catalysts suffer from poor selectivity towards a series of products, such as alkenes, alcohols, and ...carboxylic acids. Here, we used copper(ii) paddle wheel cluster-based porphyrinic metal–organic framework (MOF) nanosheets for electrocatalytic CO2 reduction and compared them with CuO, Cu2O, Cu, a porphyrin–Cu(ii) complex and a CuO/complex composite. Among them, the cathodized Cu-MOF nanosheets exhibit significant activity for formate production with a faradaic efficiency (FE) of 68.4% at a potential of −1.55 V versus Ag/Ag+. Moreover, the C–C coupling product acetate is generated from the same catalyst together with formate at a wide voltage range of −1.40 V to −1.65 V with the total liquid product FE from 38.8% to 85.2%. High selectivity and activity are closely related to the cathodized restructuring of Cu-MOF nanosheets. With the combination of X-ray diffraction, X-ray photoelectron spectroscopy, high resolution transmission electron microscopy and Fourier transform infrared spectroscopy, we find that Cu(ii) carboxylate nodes possibly change to CuO, Cu2O and Cu4O3, which significantly catalyze CO2 to formate and acetate with synergistic enhancement from the porphyrin–Cu(ii) complex. This intriguing phenomenon provides a new opportunity for the rational design of high-performance Cu catalysts from pre-designed MOFs.
This paper proposes a methodology for conducting importance-performance analysis (IPA) through online reviews. The methodology is composed of three stages: (1) mining useful information from online ...reviews, (2) estimating each attribute's performance and importance, and (3) constructing IPA plot, where the latent dirichlet allocation (LDA), the improved one-vs-one strategy based support vector machine (IOVO-SVM) and the ensemble neural network based model (ENNM) are respectively used. A case study on two five-star hotels is given, and the results obtained by the proposed methodology through online reviews are compared with those obtained by the existing methods through questionnaires (or online ratings). The results indicate that the proposed methodology can obtain effective analysis results with lower cost and shorter time since online reviews are publicly available and easily collected. The proposed methodology can give managers or market analysts one more choice for conducting IPA or serve as a preparing process of large-scale survey.
•A novel methodology for conducting IPA through online reviews is proposed.•The performance of each attribute is estimated according to the sentiment strengths of online reviews.•The importance of each attribute is estimated using ENNM.•Four types of IPA can be easily conducted through online reviews.•A case study of IPA for two five-star hotels is given.
Identifying effective means to improve the electrochemical performance of oxygen‐evolution catalysts represents a significant challenge in several emerging renewable energy technologies. Herein, we ...consider metal–nitrogen–carbon sheets which are commonly used for catalyzing the oxygen‐reduction reaction (ORR), as the support to load NiO nanoparticles for the oxygen‐evolution reaction (OER). FeNC sheets, as the advanced supports, synergistically promote the NiO nanocatalysts to exhibit superior performance in alkaline media, which is confirmed by experimental observations and density functional theory (DFT) calculations. Our findings show the advantages in considering the support effect for designing highly active, durable, and cost‐effective OER electrocatalysts.
Sitting on the FeNC: Metal–nitrogen–carbon sheets are used as the supports for metal oxide catalysts for the oxygen‐evolution reaction (OER). Iron–nitrogen–carbon (FeNC) sheets loaded with NiO nanoparticles give superior performance in alkaline media. The improved performance originates from a synergistic effect between the FeNC sheets and NiO.
A novel distal radical rearrangement of alkoxyphosphine is developed for the first time and applied to the regioselective radical fluoroalkylphosphorylation of unactivated olefins. By employing a ...one‐pot two‐step reaction of (bis)homoallylic alcohols, organophosphine chlorides, and fluoroalkyl iodides under CFL (compact fluorescence light) irradiation, a series of fluoroalkylphosphorylated alkyl iodides and alcohols are easily synthesized by regiospecific installing a phosphonyl onto the inner carbon of terminal olefins and further iodination/hydroxylation. Mechanism studies reveal that the migration undergoes a distinctive radical cyclization/β‐scission on the lone electron pair of phosphorus, resulting in C−P bond formation and C−O bond cleavage.
A regioselective radical fluoroalkylphosphorylation of unactivated alkenes is developed by a one‐pot reaction of (bis)homoallylic alcohols, phosphine chlorides, and fluoroalkyl iodides under compact fluorescence light (CFL) irradiation. This protocol employs a novel radical rearrangement of alkoxyphosphine to achieve the unusual installing of a phosphoryl in the inner side of the terminal olefins by the dehydroxylative trifunctionalization of (bis)homoallylic alcohols.
Saikosaponin A (SSA)—a natural compound extracted from Radix bupleuri—possesses antitumor properties in several types of carcinomas. However, the role of SSA on bladder cancer and the mechanisms ...remain unclear. In this study, we have described the effect of SSA on human bladder cancer cell lines T24 and 5637 in the context of the regulation of mitochondrial pathways of apoptosis. In vitro, the Cell Counting Kit-8 (CCK-8) assay and cell wound healing assays were used to determine the proliferative effect of SSA treatment. Flow cytometry and Western blotting were performed to evaluate the apoptosis and related mechanisms. To further confirm that apoptosis is mediated through Caspase activation, Hoechst 33258 fluorescence staining assay was done after cells were treated with SSA and caspase inhibitor-Z-VAD-FMK. In vivo, an orthotopic xenograft mice model was adopted to evaluate the effect of SSA. The tumors were analyzed by hematoxylin-eosin (H&E) staining, immunohistochemical analysis, and Western blotting. In vitro, the results with CCK-8 assay showed obvious SSA-induced suppression in cell growth in a dose- and time-dependent manner. Flow cytometry analysis, Hoechst 33258 fluorescence staining assay and the assessment of the changes in the B-cell lymphoma 2 (Bcl-2) family protein expression level revealed that SSA could significantly induce cell apoptosis, which was associated with apoptosis via the mitochondrial pathways. In vivo, the results revealed a reduction in cell proliferation. In conclusion, our data suggest that SSA inhibits the growth of bladder cancer cells by activating the mitochondrial apoptosis pathway and inducing cell apoptosis.
Deep eutectic solvents (DESs), also known as deep eutectic ionic liquids (DEILs) or low-melting mixtures (LMMs) or low transition temperature mixtures (LTTMs) in the literature, have become more and ...more attractive in recent years due to their interesting properties and benefits, such as low cost of components, easy to prepare, tunable physicochemical properties, negligible vapor pressure, non-toxicity, biorenewability and biodegradability. These eutectic mixtures have been widely used as green and sustainable media as well as catalysts in many chemical processes. This review focuses on recent advances using DESs in organic reactions including addition reactions, cyclization reactions, replacement reactions, multicomponent reactions, condensation reactions, oxidation reactions, and reducing reactions.
This review highlights the recent advances using deep eutectic solvents (DESs), deep eutectic ionic liquids (DEILs), low-melting mixtures (LMMs) or low transition temperature mixtures (LTTMs) as green media as well as catalysts in organic reactions.
•An improved method to eliminate the persulfate effect for carbohydrate analysis.•Sodium sulfite is the best pretreatment chemical to eliminate the persulfate effect.•The improved method is accurate ...and reliable based on the results of actual samples.
Advanced oxidation processes (AOPs) based on activated persulfate have received extensive attention for sludge pretreatment. Persulfate (PS) is a persistent oxidant and the excess persulfate in the sludge affects the carbohydrate analysis using the traditional phenol-sulfuric acid method. In this study, an improved phenol-sulfuric acid method was developed for the determination of carbohydrates in the presence of persulfate, and a critical procedure was introduced before the conventional determination with the assistance of the chemical pretreatments. The best reagent was screened from four reductants (i.e. Na2S, KI, Na2SO3 and Na2S2O3) and two free-radical scavengers (i.e. phenol and benzoic), and the optimal conditions were determined based on the monosaccharides (i.e. glucose, galactose and mannose) and the polysaccharides in different EPS fractions from two activated sludges. The results showed that Na2SO3 was the best reagent for chemical pretreatment due to redox reaction, high selectivity and colorless oxidation product, and the others were not suitable as pretreatment reagents mainly since the reaction products affect the final spectral analysis. Besides, the optimal Na2SO3 concentration for eliminating the impact of PS was 150 mmol/L, and the relative deviation of measurement is less than 5% if the PS concentration was on more than 100 mmol/L, regardless of the kinds of carbohydrates. Compared with the anthrone-sulfuric acid method and the sulfuric method, the improved phenol-sulfuric acid method has a great advantage for determining the carbohydrate concentration in the presence of PS.
Transition metal catalyzed C−H phosphorylation remains an unsolved challenge. Reported methods are generally limited in scope and require stoichiometric silver salts as oxidants. Reported here is an ...electrochemically driven RhIII‐catalyzed aryl C−H phosphorylation reaction that proceeds through H2 evolution, obviating the need for stoichiometric metal oxidants. The method is compatible with a variety of aryl C−H and P−H coupling partners and particularly useful for synthesizing triarylphosphine oxides from diarylphosphine oxides, which are often difficult coupling partners for transition metal catalyzed C−H phosphorylation reactions. Experimental results suggest that the mechanism responsible for the C−P bond formation involves an oxidation‐induced reductive elimination process.
Electric cell: Reported herein is an electrochemically driven RhIII‐catalyzed aryl C−H phosphorylation reaction which proceeds through H2 evolution. The method is compatible with a variety of aryl C−H and P−H coupling partners and particularly useful for synthesizing triarylphosphine oxides from diarylphosphine oxides. Experimental results suggest that the mechanism responsible for the C−P bond formation involves an oxidation‐induced reductive elimination process. DG=directing group.
•k-interactive fuzzy measure introduced as a way to reduce complexity.•New efficient methods of fuzzy measure learning from data are presented.•Significant improvements to efficiency of learning ...fuzzy measures.
Fuzzy measures model interactions between the inputs in aggregation problems. Their complexity grows exponentially with the dimensionality of the problem, and elicitation of fuzzy measure coefficients either from domain experts or from empirical data is a significant challenge. The notions of k-additivity and k-maxitivity simplify the fuzzy measures by limiting interactions to subsets of up to k elements, but neither reduces the complexity of monotonicity constraints. In this paper we explore various approaches to further reduce the complexity of learning fuzzy measures. We introduce the concept of k-interactivity, which reduces both the number of variables and constraints, and also the complexity of each constraint. The learning problem is set as a linear programming problem, and its numerical efficiency is illustrated on numerical experiments. The proposed methods allow efficient learning of fuzzy measures in up to 30 variables, which is significantly higher than using k-additive and k-maxitive fuzzy measures.
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