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The slow reaction kinetics and structural instability of organic electrode materials limit the further performance improvement of aqueous zinc‐organic batteries. Herein, we have synthesized a Z‐folded hydroxyl polymer polytetrafluorohydroquinone (PTFHQ) with inert hydroxyl groups that could be partially oxidized to the active carbonyl groups through the in situ activation process and then undertake the storage/release of Zn2+. In the activated PTFHQ, the hydroxyl groups and S atoms enlarge the electronegativity region near the electrochemically active carbonyl groups, enhancing their electrochemical activity. Simultaneously, the residual hydroxyl groups could act as hydrophilic groups to enhance the electrolyte wettability while ensuring the stability of the polymer chain in the electrolyte. Also, the Z‐folded structure of PTFHQ plays an important role in reversible binding with Zn2+ and fast ion diffusion. All these benefits make the activated PTFHQ exhibit a high specific capacity of 215 mAh g−1 at 0.1 A g−1, over 3400 stable cycles with a capacity retention of 92 %, and an outstanding rate capability of 196 mAh g−1 at 20 A g−1. [ABSTRACT FROM AUTHOR]

The slow reaction kinetics and structural instability of organic electrode materials limit the further performance improvement of aqueous zinc‐organic batteries. Herein, we have synthesized a Z‐folded hydroxyl polymer polytetrafluorohydroquinone (PTFHQ) with inert hydroxyl groups that could be partially oxidized to the active carbonyl groups through the in situ activation process and then undertake the storage/release of Zn2+. In the activated PTFHQ, the hydroxyl groups and S atoms enlarge the electronegativity region near the electrochemically active carbonyl groups, enhancing their electrochemical activity. Simultaneously, the residual hydroxyl groups could act as hydrophilic groups to enhance the electrolyte wettability while ensuring the stability of the polymer chain in the electrolyte. Also, the Z‐folded structure of PTFHQ plays an important role in reversible binding with Zn2+ and fast ion diffusion. All these benefits make the activated PTFHQ exhibit a high specific capacity of 215 mAh g−1 at 0.1 A g−1, over 3400 stable cycles with a capacity retention of 92 %, and an outstanding rate capability of 196 mAh g−1 at 20 A g−1. [ABSTRACT FROM AUTHOR]

Potassium Rankine cycle is one of the best thermoelectric conversion schemes for high power output of space nuclear power. Thermodynamic analysis is an important theoretical basis for perfecting cycle system performance. In this work, the output power requirements of space missions are summarized to determine the research objective of 100 kW cycle system, and a thermodynamic analysis model is established. Energy analysis and exergy analysis are introduced to measure the effective use and irreversibility of energy respectively. Secondly, the thermodynamic properties of potassium under saturated and superheated conditions are presented. Finally, the effects of five operating parameters: vapor temperature, vapor pressure, exhaust temperature, condenser outlet temperature and split ratio on the thermal performance of the system are investigated. The results show that the increase of vapor temperature, vapor pressure and main loop flow, the decrease of exhaust temperature are effective measures to improve the thermal performance of the system. Meanwhile, the enhancement of boiler heat transfer performance is the key to reducing system energy loss. This work is of great significance to the improvement of thermal performance and the clarification of optimization direction of alkali metal Rankine cycle system. • Constraints on components and system in the potassium Rankine cycle are given. • Exergy model is introduced to evaluate the irreversibility of the cycle system. • The effect of operating parameters on system performance is investigated. • The enhancement of boiler heat transfer is a key to optimize system performance. • The power requirements of space missions can be matched by parameter adjustment. [ABSTRACT FROM AUTHOR]

• A new method for obtaining enthalpy and entropy of alkali metal superheated steam is proposed. • The accuracy of the enthalpy and entropy prediction models based on RBFNN is above 90%. • Evaluation indicators: residuals, SSE, MSE, ME, R 2 are introduced to measure the prediction models. • The prediction model has good practicality and extensibility. The alkali metal Rankine cycle system has great advantages in space nuclear power system. The investigation of thermodynamic properties of alkali metals is fundamental to develop thermodynamic model of thermoelectric conversion system. This paper build models for predicting the thermodynamic properties of alkali metals (potassium, sodium, cesium, rubidium) by statistics and machine learning. Pearson correlation analysis is performed to explain the correlation between measurable variables (temperature, pressure, specific volume, specific heat capacity) and unmeasurable variables (enthalpy, entropy). Ridge regression and radial basis artificial neural network models are established for the enthalpy and entropy of alkali metals respectively. Five evaluation indicators: residual, SSE, MSE, ME and R 2 are selected to evaluate the accuracy of different types of prediction models. The practicability and extensibility of the prediction model are proved by case analysis. The results show that the prediction model of enthalpy and entropy based on radial basis neural network has high accuracy, and R 2 can reach above 0.9. The entropy prediction model can even be stable at 0.999 when applied to different operating conditions and alkali metals. The new method proposed in this work solves the difficulty of experimental measurement in high temperature section to some extent, and opens a new idea for studying the properties of working medium. At the same time, the validation of the extrapolation feasibility of this method is of great significance to improve the thermodynamic properties database of alkali metals in the whole temperature range. [ABSTRACT FROM AUTHOR]

The performance of electrode material is correlated with the choice of electrolyte, however, how the solvation has significant impact on electrochemical behavior is underdeveloped. Herein, N‐heteropentacenequinone (TAPQ) is investigated to reveal the solvation effect on the performance of sodium‐ion batteries in different electrolyte environment. TAPQ cycled in diglyme‐based electrolyte exhibits superior electrochemical performance, but experiences a rapid capacity fading in carbonate‐based electrolyte. The function of solvation effect is mainly embodied in two aspects: one is the stabilization of anion intermediate via the compatibility of electrode and electrolyte, the other is the interfacial electrochemical characteristics influenced by solvation sheath structure. By revealing the failure mechanism, this work presents an avenue for better understanding electrochemical behavior and enhancing performance from the angle of solvation effect. [ABSTRACT FROM AUTHOR]

The performance of electrode material is correlated with the choice of electrolyte, however, how the solvation has significant impact on electrochemical behavior is underdeveloped. Herein, N‐heteropentacenequinone (TAPQ) is investigated to reveal the solvation effect on the performance of sodium‐ion batteries in different electrolyte environment. TAPQ cycled in diglyme‐based electrolyte exhibits superior electrochemical performance, but experiences a rapid capacity fading in carbonate‐based electrolyte. The function of solvation effect is mainly embodied in two aspects: one is the stabilization of anion intermediate via the compatibility of electrode and electrolyte, the other is the interfacial electrochemical characteristics influenced by solvation sheath structure. By revealing the failure mechanism, this work presents an avenue for better understanding electrochemical behavior and enhancing performance from the angle of solvation effect. [ABSTRACT FROM AUTHOR]

Polo like kinase 1 (PLK1) is a protein kinase involved in regulating the spindle assembly and cell cycle control in mammalian oocytes. SUMOylation, one way of post‐translational modification, regulates oocyte meiosis by controlling several substrates. However, the relation between PLK1 and SUMOylation in oocytes is still unknown. In this study, we investigated that whether PLK1 was modified by SUMOylation in oocytes and its potential relationship with age‐related meiotic abnormalities. We showed that PLK1 had colocalization and protein interaction with Small Ubiquitin‐Like Modifier (SUMO)‐1 and SUMO‐2/3 in mouse oocytes, indicating that PLK1 could be modified by SUMO‐1 and SUMO‐2/3. Overexpression of PLK1 SUMOylation site mutants PLK1K178R and PLK1K191R caused the increase of the abnormal spindle rate of oocytes and the decline of the first polar body extrusion rate with the abnormal localization of PLK1, suggesting that the SUMOylation modification of PLK1 is essential for normal meiosis in oocytes. Compared with young mice, the expression of PLK1 protein increased and the expression of SUMO‐1 and SUMO‐2/3 protein decreased in the oocytes of aged mice, indicating that the SUMOylation of PLK1 might be related to the mouse aging. Therefore, our data suggested that PLK1 could be SUMOylated by SUMO‐1 and SUMO‐2/3 in mouse oocytes and SUMOylation of PLK1 regulated the meiosis progression of oocytes which was related with aging. [ABSTRACT FROM AUTHOR]