Prussian blue analogue material is regarded as an ideal cathode candidate for Li-ion batteries due to its open 3D frame structure and various transition metals with different valence states. However, poor electronic conductivity and structural collapse severely limit its application in the electrochemical field. In this work, Na1.13Fe[Fe(CN)]6·3.22H2O electrode materials with stepwise hollow inverted pyramid morphology are prepared by simple hydrothermal method. The inverted pyramid Na1.13Fe[Fe(CN)]6·3.22H2O maintains the stability of the crystal structure and slows down the volume expansion during the Li + insertion-extraction process. Benefiting from the unique structure and composition, the discharge specific capacities of the optimal Na1.13Fe[Fe(CN)]6·3.22H2O electrode (FeHCF-2) are 153.7, 126.28, 119.4 and 113.4, 107.61, 102.52 and 92.46 mAh·g−1 at 0.1, 0.3, 0.5, 1, 2, 5 and 10 C, respectively. The first discharge capacity of FeHCF-2 electrode at 1 C is 111.88 mAh·g−1, and the discharge capacity of FeHCF-2 electrode is 115.04 mAh·g−1 after 1000 cycles, indicating that FeHCF-2 electrode has ultrastable cycle stability. Therefore, designing the hollow inverted pyramid morphology can be regarded as an available way to enhance the electrochemical activity of Na1.13Fe[Fe(CN)]6·3.22H2O for advanced lithium-ion batteries, and effective design strategies can be used for the modification of other cathode materials for Li-ion batteries. 

Rational construction of Prussian blue analogue with inverted pyramid morphology as ultrastable cathode material for lithium-ion battery

The phenomenon of a bubble bursting to generate droplets exists in industrial and environmental systems and has a subtle impact on our daily lives. A bubble generated by gas injection or heating rises to the free surface and undergoes floating, drainage, and eventually bursting processes to produce film and jet droplets. The interrelated processes make it difficult to understand the characteristics of a bubble burst. Thus, a summary of the individual stages of a single bubble from generation to burst is necessary. First, we describe the calculation method and simple expressions for the shape of a bubble floating on a free surface. Next, we discuss the bubble drainage model and its influencing factors as this directly determines the time evolution of the film thickness. As an essential factor that affects the film thickness, the bubble drainage time is defined as the bubble lifetime. We compare the bubble lifetime distributions in the published literature and explore the associated influencing factors. Then, we investigate the bubble bursting dynamics and focus on the bubble film opening process once a hole appears on its surface. As a legacy of bubble burst, we explore the production process, size, and number of film and jet droplets. Finally, we discuss the enrichment phenomenon and the enrichment factors of film and jet droplets when releasing particles entrained by droplets. This review considers a series of processes for bubble burst to generate droplets and concentrates on the mechanism and experimental correlations with a summary and future prospects.

Bubble floatation, burst, drainage, and droplet release characteristics on a free surface: A review

Integration of pool scrubbing research to enhance Source-Term calculations (IPRESCA) project – Overview and first results

Ni-based selenide has flourished as one of the most competitive anode materials for sodium-ion batteries due to its low cost, wide source, and high theoretical specific capacity. As one of the members, NiSe microparticles with the sizes of 2.0–10.6 μm are synthesized with disused nickel foam fragments by a facile and rapid one-step selenization method, possessing a prominent rate capability of 304.3 mAh g–1 at 15 A g–1 and a remarkable lifespan with 291.7 mAh g–1 after 1600 cycles at 2 A g–1. A Na3V2(PO4)2F3@reduced graphene oxide//NiSe full cell also exhibits excellent sodium storage behavior and potential utility, achieving the largest power density of 1919.0 W Kg–1, the highest energy density of 146.0 Wh kg–1, and a capacity of 119.7 mAh g–1 after 600 cycles at 1 A g–1 accompanied by impressive Coulombic efficiency (>95%, except for the first two cycles). The reversible phase transition, proper use of the ether electrolyte, low electrochemical impedance, and favorable structural stability all synergistically contribute to the satisfactory electrochemical property of NiSe. This work effectively improves the preparation efficiency of NiSe, tendering a new synthetic route for the anode materials. 

Facile Development of Disused Nickel Foams into Low-Cost and High-Performance Electrode Materials for Sodium-Ion Batteries

In this study, a technical index system for nuclear accident emergency response measures was established and comprehensively evaluated by studying the impact of time, ventilation speed, and leakage speed on the radiation consequences after a loss of coolant accident (LOCA) in a marine reactor. The weight of each index was calculated by the analytic hierarchy process (AHP), and the weight of the radiation protection measure in the second-level index emergency measure was 0.625, accounting for the maximum proportion. The weights of improving radionuclide detection technology in chambers, improving detection capability, and improving the diagnosis efficiency of radiation damage in the three-level indicator emergency measures were 0.4442, 0.4384, and 0.4521, respectively, accounting for the maximum proportions. The fuzzy comprehensive evaluation method was used to quantify and comprehensively evaluate the index system of emergency measures. The quantitative evaluation result was 82.8 points, indicating that the evaluation result was adequate. Therefore, the nuclear emergency response measure based on the radiation consequences of a marine reactor LOCA is reasonable and feasible. It provides valuable measures and practical guidance for the emergency response of a marine reactor LOCA, and dramatically reduces the harm of radiation to staff and the environment.

/pdf/evaluation-of-emergency-response-measures-for-the-loca-of-a-2mv8vp66.pdf

Evaluation of Emergency Response Measures for the LOCA of A Marine Reactor

Given the merits of rich reserves, high ion conductivity and non-combustion property, aqueous sodium ion batteries (SIBs) were once considered as high-quality substitutes for organic lithium ion batteries . However, due to the large radius of carrier sodium ion and unstable structure of electrode materials, the practical implementation of aqueous SIBs is seriously impeded. In this work, a reliable aqueous SIB is constructed by employing Na 2 Co[Fe(CN) 6 ] as cathode, which is synthesized by co-precipitation assisted electrochemical synthesis. As a Prussian blue analogue (PBA), Na 2 Co[Fe(CN) 6 ] inherits open framework structure, ion insertion stability and electrochemical tunability. Benefitting from common ion effect, Na 2 Co[Fe(CN) 6 ] can maintain stable host structure in the SIBs with CoSO 4 as an additive of electrolyte, and exhibits an exceptional cycling stability without capacity decay over 2000 cycles and outstanding rate performance. By further exploring the changes in crystal structure, elemental valence states and ion storage kinetics, it fully explains the structural and electrochemical stability of Na 2 Co[Fe(CN) 6 ] as the cathode for aqueous SIBs and the mechanism of Na + insertion/extraction during cycling process. This work provides a pathway to settle the problems of large carrier ion and structural instability in aqueous SIBs, and greatly broadens the path of its research and development. • Na 2 Co[Fe(CN) 6 ] is synthesized by electrochemical assisted co-precipitation. • Common ion effect enhances the electrochemical property of sodium ion battery. • The capacity retention is as high as 100% over 2000 cycles at 1000 mA g −1 . • The Na + storage mechanism is related to the bimetallic redox reaction. 

Common ion effect enhanced cobalt hexacyanoferrate for aqueous Na-ion battery

Safety analysis of marine nuclear reactor in severe accident with dynamic fault trees based on cut sequence method

Experimental study on the release of droplets via bubble bursting under different liquid phase conditions

Suspension waterjet peening is an emerging technology for surface modification. Coverage is a key factor affecting the integrity of a modified material surface, however such an experimental method that can be utilized for precise control has not yet been established. To determine the numerical value of coverage after surface peening treatment, In this paper, a coverage analytical method was proposed and then verified by the results through experiments. Furthermore, to explore the impact of high coverage on surface integrity, a large-scale coverage peening modification was performed on 18CrNiMo7-6 carburized steel specimens using a specialized suspension waterjet equipment. The results indicate that coverage has a significant impact on roughness and compressive residual stress field, with the highest improvement on surface and their maximum values reaching 51.6% and 24.7%, respectively. It is shown that the fatigue performance of the specimens can be significantly enhanced.

https://iopscience.iop.org/article/10.1088/2053-1591/acdfa9/pdf

Junlong Wang

Papers

Common ion effect enhanced cobalt hexacyanoferrate for aqueous Na-ion battery

Safety analysis of marine nuclear reactor in severe accident with dynamic fault trees based on cut sequence method

Experimental study on the release of droplets via bubble bursting under different liquid phase conditions

Analytical model for predicting coverage in suspension waterjet shot peening and its influence on fatigue