Search

The proton exchange membrane electrolysis cell (PEMEC) has attracted considerable attention for large-scale and efficient hydrogen production because of its high current density, high hydrogen purity and fast dynamic response. Flow field distributions and water and thermal management characteristics of a PEMEC are vital for electrolytic cell structure and the determination of operating condition. A three-dimensional, non-isothermal, electrochemical model of a PEMEC was established in this manuscript. The flow field distribution and water and thermal management of the PEMEC are discussed. The corresponding results showed that the pressure of the flow channel decreased diagonally from the inlet to the outlet, and the pressure and velocity distribution exhibited a downward opening shape of a parabola. At the same inlet flow rate, when the voltage was 1.6 V, the oxygen generation rate was 15.74 mol/(cm2·s), and when the voltage was 2.2 V, the oxygen generation rate was 332.05 mol/(cm2·s); due to the change in the oxygen production rate, the pressure difference at 2.2 V was 2.5 times than that at 1.6 V. When the stoichiometric number was less than two, the average temperature of the catalyst layer (CL) decreased rapidly with the increase in the water flow rate. When the voltage decreased to 2.1 V, the current density came to the highest value when the stoichiometric number was 0.7, then the current density decreased with an increase in the stoichiometric number. When stoichiometric numbers were higher than five, the surface temperature and current density remained basically stable with the increase in the water flow rate, and the water and thermal management and electrolysis characteristics performed better. The research results could optimize the water supply of electrolysis cells. According to the velocity distribution law of the flow field, the water and thermal management performance of the PEMEC could be estimated, further promoting safety and reliability. [ABSTRACT FROM AUTHOR]

Myocardial infarction (MI) remains a major threat to human health due to the limited energy supply, disordered cell metabolism, massive cardiomyocyte death, and restricted regeneration. Although currently available therapies may relieve myocardial damage, restoring the dysregulated energy metabolism to normal levels has not yet been achieved. MOTS‐c has recently been identified as a regulator of biological metabolism to combat aging; however, its role in reprogramming cardiac metabolism remains to be elucidated. Here, MOTS‐c is chemically conjugated to self‐assembling Q11 peptide to fabricate an injectable hydrogel (MQgel) aimed to improve mitochondria function and cardiomyocyte metabolism post‐MI. It is observed that MQgel effectively protects mitochondria from oxidative damage and normalized cardiomyocyte metabolism, including glucose uptake, glycolysis, and the tricarboxylic acid (TCA) cycle, thereby inhibiting cardiomyocyte death and enhancing cardiomyocyte activity. In a rat MI model, intramyocardial injection of MQgel successfully minimizes the infarct area and fibrosis, promotes angiogenesis, suppresses myocardial hypertrophy, and improves cardiomyocyte survival and metabolic enzyme activity, all of which collaboratively attenuate the maladaptive cardiac remodeling and boost cardiac function and tissue repair. The findings suggest that the self‐assembled mitochondria metabolism‐regulatory peptide hydrogel effectively treats MI, and cellular bioenergy modulation provides a new therapeutic approach for tissue repair after injury. [ABSTRACT FROM AUTHOR]

Electric vehicles (EVs) are experiencing explosive developments due to their advantages in energy conservation and environmental protection. As a pivotal component of EVs, the safety performance of lithium-ion batteries directly affects driving miles and even safety; hence, a battery thermal management system (BTMS) is especially important. To improve the thermal safety performance of power battery modules, first, a new leak-proof phase change material (PCM)-coupled liquid-cooled composite BTMS for large-scale battery modules is proposed in this research. Second, the numerical simulation analysis method was utilized to analyze the influences of the fluid flow channel shape, working fluid inlet temperature, inlet velocity, and reverse flow conditions on the BTMS. Eventually, the abovementioned performances were compared with the traditional PCM-coupled liquid-cooling strategy. The relative data indicated that the Tmax was reduced by 17.5% and the ΔTmax was decreased by 19.5% compared to the liquid-cooling approach. Further, compared with conventionally designed PCM composite liquid cooling, the ΔTmax was reduced by 34.9%. The corresponding data showed that, when using the e-type flow channel, reverse flow II, the inlet flow velocity was 0.001–0.005 m/s, and the inlet temperature was the ambient temperature of the working condition. The thermal performance of the anti-leakage system with a thermal conduction slot PCM-coupled liquid-cooling composite BTMS reached optimal thermal performance. The outcome proved the superiority of the proposed BTMS regarding temperature control and temperature equalization capabilities. It also further reduced the demand for liquid-cooling components, avoided the problem of the easy leakage of the PCM, and decreased energy consumption. [ABSTRACT FROM AUTHOR]

Myopia is a globally emerging concern accompanied by multiple medical and socio-economic burdens with no well-established causal treatment to control thus far. The study of the genomics and transcriptomics of myopia treatment is crucial to delineate disease pathways and provide valuable insights for the design of precise and effective therapeutics. A strong understanding of altered biochemical pathways and underlying pathogenesis leading to myopia may facilitate early diagnosis and treatment of myopia, ultimately leading to the development of more effective preventive and therapeutic measures. In this review, we summarize current data about the genomics and transcriptomics of myopia in human and animal models. We also discuss the potential applicability of these findings to precision medicine for myopia treatment. [ABSTRACT FROM AUTHOR]

A cobalt‐catalyzed cascade reaction of N‐aryl thiocarbamoyl fluorides and water has been developed, providing access to 3‐alkyl‐2(3H)‐benzothiazolones in 48–83% yields. This protocol for 3‐alkyl‐2(3H)‐benzothiazolones precludes bad‐smell and toxic reagents. Mechanistic studies suggest that the transformation proceeds through hydrolysis followed by dehydrogenative coupling to form C−S bond involving a radical process. [ABSTRACT FROM AUTHOR]

To solve the problem that the curing mechanism evolution of phenolic resin catalyzed by Ba(OH)2 remained unclear, the p-p methylene index, o-p methylene index, o-o methylene index, hydroxymethyl index, and ether index were introduced to quantitatively investigate the chemical structure of resin in the curing temperature range of 90–230°C. The chemical structures were investigated by variable temperature FT-IR. The gas products released with the increase of curing temperature were characterized by Thermogravimetry-Mass Spectrometry. The curing mechanism from 90°C to 230°C was concluded finally. The results show that the main reaction is the formation of the p-p methylene group in the range of 90–120°C. It is difficult to form the o-p methylene bridge at this stage. In the range of 120–160°C, the main reaction is the formation of the p-p methylene group. From 160°C to 190°C, the main reactions are the breaking of the ether bond, the formation of the carbonyl group and the propyl bridge. Above 190°C, the main reactions are polycondensation reaction among phenolic hydroxyl groups, and the formation reaction of carbonyl groups. The ether bond breaks completely above 230°C. This work provides a new method to investigate the curing mechanism. It is a benefit for the rational design of the curing process of phenolic resin-based composites. [ABSTRACT FROM AUTHOR]

For the first time, cotton fiber-shaped Cu2O nanoparticles were prepared onto the surface of a commercial copper (Cu) foil via a very simple immersion method at room temperature in which the soaking solution only contained CuSO4, Na2S2O3, and a very little amount of 1-butyl-3-methylimidazolium trifluoroacetate. In this work, the current collectors prepared using 1 mM, 2 mM, and 3 mM Na2S2O3 were, respectively, nominated as current collectors a, b, and c. Interestingly, a cotton fiber-shaped spatial network structure assembled by a large number of 10-nm-sized nanoparticles was presented on the surface of current collector b. The initial discharge capacity (DC) at 0.1 A g−1 of electrode b, namely, the graphite electrode assembled using current collector b, was as high as 467 mAh g−1, almost 1.65 times larger than that of the conventional graphite electrode. Particularly, at 0.5 A g−1 after 10 cycles, the DC value of electrode b (105 mAh g−1) was still about 1.8 times higher than that of the conventional graphite electrode (59 mAh g−1). An immersion method for preparing Cu2O-modified Cu foil at room temperature is developed in this work, which is very meaningful to the development of the Cu foil-based commercial graphite electrode, since no additional energy consumptions and no variations of the electrode preparation process are required. [ABSTRACT FROM AUTHOR]

An iron‐catalyzed intramolecular dehydrogenative C−S bond formation from 1‐aryl‐1‐alkyl‐3‐aroyl thioureas via FeCl3 as catalyst, Na2CO3 as base, and Na2S2O8 as oxidant has been developed. A variety of 3‐alkyl‐2‐(N‐aroyl)imino‐benzo[d]thiazolines are obtained in moderate to excellent yields with excellent chemoselectivity in an atom‐economic fashion. In addition, 1‐aryl‐1‐alkyl‐3‐aroyl thioureas have been synthesized from N‐aryl‐N‐alkyl thiocarbamoyl fluorides (sufur form S8) with aromatic amides under NaOH in moderate to good yields. [ABSTRACT FROM AUTHOR]

By now, as the promising high‐energy cathode materials of lithium‐ion batteries (LIBs), the high‐nickel LiNi0.8Co0.1Mn0.1O2 (NCM811) still have technical problems such as poor electrode‐electrolyte interface stability and sensitivity to H2O and HF in the electrolyte to be solved. In this work, isocyanoethyl methacrylate (IMA) containing −N=C=O group is developed as a bifunctional electrolyte additive through the film‐forming, H2O removal, and HF reduction to modify the electrode‐electrolyte interfaces and improve the performance of NCM811/graphite LIBs. After 450 cycles under the normal voltage range of 2.75 to 4.20 V, the capacity retention of the battery with 0.5 wt.% IMA additive increases from 50.7 % to 78.0 % compared to the battery without the additive. And under the high voltage range of 2.75 to 4.40 V, the capacity retention of the battery with IMA increases from 62.8 % to 81.9 % after 150 cycles. It is demonstrated that the IMA additive as the H2O and HF scavenger of electrolyte also facilitate the electrochemical oxidation‐reduction reactions on two electrodes to form high‐quality interfacial films, which stabilizes the anode and cathode interfaces and subsequently improves the cycling performance of the batteries. These results show that the electrolyte with IMA additive has promising prospects in the application of high‐nickel NCM‐based LIBs and provide the idea to evaluate the organic molecules containing −N=C=O group as the functional electrolyte additives as well. [ABSTRACT FROM AUTHOR]