Temperature‐dependent dual fluorescence and switchable circularly polarized luminescence (CPL) are two highly pursued but challenging properties for small organic molecules (SOMs). We herein disclose ...a triarylborane π‐system based on a 2,2′‐diamino‐6,6′‐diboryl‐1,1′‐binaphthyl scaffold that can serve as a versatile building block for achieving these two properties by simply choosing different amino groups. BNMe2‐BNaph with less bulky dimethylamino groups displays temperature‐dependent dual fluorescence, and can thus be used as a highly sensitive ratiometric fluorescence thermometer. On the other hand, BNPh2‐BNaph with bulky diphenylamino groups exhibits intense fluorescence in both solution and in the solid state. A change of solvent from nonpolar cyclohexane to highly polar MeCN not only shifts the CPL position to much longer wavelength but also inverts the CPL sign. In addition, the complexation of BNPh2‐BNaph with fluoride greatly enhances the CPL intensity.
The combination of two donor–π‐acceptor subunits in the 2,2′‐diamino‐6,6′‐diboryl‐1,1′‐binaphthyl scaffold generates a versatile building block for organic fluorophores exhibiting temperature‐dependent dual fluorescence and switchable circularly polarized luminescence.
Ionic liquids (ILs) have evolved as a new type of non-aqueous solvents for biocatalysis, mainly due to their unique and tunable physical properties. A number of recent review papers have described a ...variety of enzymatic reactions conducted in IL solutions; on the other hand, it is important to systematically analyze methods that have been developed for stabilizing and activating enzymes in ILs. This review discusses the biocatalysis in ILs from two unique aspects (1) factors that impact the enzyme's activity and stability, (2) methods that have been adopted or developed to activate and/or stabilize enzymes in ionic media. Factors that may influence the catalytic performance of enzymes include IL polarity, hydrogen-bond basicity/anion nucleophilicity, IL network, ion kosmotropicity, viscosity, hydrophobicity, the enzyme dissolution, and surfactant effect. To improve the enzyme's activity and stability in ILs, major methods being explored include the enzyme immobilization (on solid support, sol-gel, or CLEA), physical or covalent attachment to PEG, rinsing with n-propanol methods (PREP and EPRP), water-in-IL microemulsions, IL coating, and the design of enzyme-compatible ionic solvents. It is exciting to notice that new ILs are being synthesized to be more compatible with enzymes. To utilize the full potential of ILs, it is necessary to further improve these methods for better enzyme compatibility. This is what has been accomplished in the field of biocatalysis in conventional organic solvents. Copyright
The circularly polarized luminescence (CPL) switching is of significant interest for applications in security technologies and sensing devices. Small organic molecules (SOMs) show several advantages ...over metal complexes, supramolecular assemblies, and polymers. Therefore, the recent progress on the CPL switching in SOMs is here reviewed. The results are summarized based on the strategies used to tune factors that influence the emission properties, and thus, to realize CPL switching. The strategies that have been adopted include promoting the excimer formation of fluorescent units, changing the conformation of fluorophores, tuning the electronic structure of the π‐skeleton/substituent, and modulating the intramolecular charge‐transfer dynamics.
Switching! The circularly polarized luminescence (CPL) switching in small organic molecules (SOMs) is of great interest. However, the achievement of such a property is very challenging. In this minireview, the strategies that have been recently adopted are summarized.
A global parameter estimation method for a permanent magnet synchronous machines (PMSM) drive system is proposed, where the electrical parameters, mechanical parameters, and voltage-source-inverter ...(VSI) nonlinearity are regarded as a whole and parameter estimation is formulated as a single parameter optimization model. A dynamic learning estimator is proposed for tracking the electrical parameters, mechanical parameters, and VSI of PMSM drive by using dynamic self-learning particle swarm optimization (DSLPSO). In DSLPSO, a novel movement modification equation with dynamic exemplar learning strategy is designed to ensure its diversity and achieve a reasonable tradeoff between the exploitation and exploration during the search process. Moreover, a nonlinear multiscale based interactive learning operator is introduced for accelerating the convergence speed of the <inline-formula><tex-math notation="LaTeX"> Pbest</tex-math></inline-formula> particles; meanwhile a dynamic opposition-based learning strategy is designed to facilitate the <inline-formula><tex-math notation="LaTeX">gBest</tex-math></inline-formula> particle to explore a potentially better region. The proposed algorithm is applied to parameter estimation for a PMSM drive system. The results show that the proposed method has better performance in tracking the variation of electrical parameters, and estimating the immeasurable mechanical parameters and the VSI disturbance voltage simultaneously.
Abstract
Glucose electrolysis offers a prospect of value-added glucaric acid synthesis and energy-saving hydrogen production from the biomass-based platform molecules. Here we report that ...nanostructured NiFe oxide (NiFeO
x
) and nitride (NiFeN
x
) catalysts, synthesized from NiFe layered double hydroxide nanosheet arrays on three-dimensional Ni foams, demonstrate a high activity and selectivity towards anodic glucose oxidation. The electrolytic cell assembled with these two catalysts can deliver 100 mA cm
−2
at 1.39 V. A faradaic efficiency of 87% and glucaric acid yield of 83% are obtained from the glucose electrolysis, which takes place via a guluronic acid pathway evidenced by in-situ infrared spectroscopy. A rigorous process model combined with a techno-economic analysis shows that the electrochemical reduction of glucose produces glucaric acid at a 54% lower cost than the current chemical approach. This work suggests that glucose electrolysis is an energy-saving and cost-effective approach for H
2
production and biomass valorization.
A dynamic particle swarm optimization with learning strategy (DPSO-LS) is proposed for key parameter estimation for permanent magnet synchronous machines (PMSMs), where the voltage-source inverter ...(VSI) nonlinearities are taken into account in the parameter estimation model and can be estimated simultaneously with other machine parameters. In the DPSO-LS algorithm, a novel movement modification equation with variable exploration vector is designed to effectively update particles, enabling swarms to cover large areas of search space with large probability and thus the global search ability is enhanced. Moreover, a Gaussian-distribution-based dynamic opposition-based learning strategy is developed to help the pBest jump out local optima. The proposed DPSO-LS can significantly enhance the estimator model accuracy and dynamic performance. Finally, the proposed algorithm is applied to multiple parameter estimation including the VSI nonlinearities of a PMSM. The performance of DPSO-LS is compared with several existing PSO algorithms, and the comparison results show that the proposed parameters estimation method has better performance in tracking the variation of machine parameters effectively and estimating the VSI nonlinearities under different operation conditions.
A
bstract
In this paper, we consider the imbedding of the popular and well-motivated trimaximal mixing and
μ
–
τ
reflection symmetry (which can help us shape the forms of the neutrino mass matrix) in ...the minimal seesaw model (which contains much fewer parameters than the general seesaw model) with two TeV-scale right-handed neutrinos (for realizing a low-scale seesaw) of nearly degenerate masses (for realizing a resonant leptogenesis). However, either for the trimaximal mixing scenario (which is realized through the Form Dominance approach here) or for the
μ
–
τ
reflection symmetry scenario, leptogenesis cannot proceed. To address this issue, we consider the possibility that the special forms of the neutrino mass matrix for the trimaximal mixing and
μ
–
τ
reflection symmetry are slightly broken by the renormalization group evolution effect, thus allowing leptogenesis to proceed. It is found that in the normal case of the neutrino mass ordering, the baryon asymmetry thus generated can reproduce the observed value. For completeness, we have also extended our analysis to the scenario that two right-handed neutrinos are not nearly degenerate any more. Unfortunately, in this scenario the final baryon asymmetry is smaller than the observed value by several orders of magnitude.
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•Combined effects of MPs and BHA on zebrafish embryos/larvae were evaluated.•MPs promoted the accumulation of BHA in zebrafish larvae.•MPs enhanced the toxicity of BHA in larvae ...development.•Coexposure disturbed arachidonic acid, glycerophospholipid, and lipids metabolism.
Coexposure of MPs and other contaminants adsorbed from the environment has raised many attentions, but the understanding of the combined effects of MPs and plastic additives are limited. Butylated hydroxyanisole (BHA), a widely used synthetic phenolic antioxidant in plastics, has gained high concerns due to their unintended environmental release and potential threat to aquatic organisms. This study was conducted to reveal the influences of MPs on the bioaccumulation and developmental toxicity of BHA in zebrafish larvae. As a result, MPs promoted the accumulation of BHA in zebrafish larvae and enhanced the toxicity of BHA in larvae development manifested by reduced hatching rates, increased malformation rates and decreased calcified vertebrae. Although the concentration of MPs was not sufficient to cause obvious developmental toxicity, the impacts of MPs on thyroid hormones status might contribute to the aggravated join toxicity. The metabolomic mechanism was revealed to be that the coexposure of BHA and MPs affected the development of zebrafish larvae via disturbing the metabolism of arachidonic acid, glycerophospholipid, and lipids. Our results emphasized that MPs, even at the nontoxic concentrations, in combination with additives caused health risk that should not be ignored.
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