Sodium-ion capacitors represent a novel class of energy storage device that integrates the respective advantages of sodium-ion batteries and electric double-layer capacitors. Nevertheless, the mismatch between the positive and negative electrode kinetics of sodium ion capacitors can lead to their low power density and poor cycling stability. Since the advent of single-atom catalysis, single-atom metals have garnered substantial attention in energy storage research due to their high atomic efficiency, exceptional catalytic activity, superior selectivity, and remarkable stability.Firstly, the challenges faced by electrode materials for sodium ion capacitors were elaborated, and the energy storage mechanism of sodium ion capacitors was analyzed. Secondly, the characteristics of single atom catalysts and the preparation methods of carbon supported metal single atom materials were introduced. Then, the application progress of metal monatomic materials in sodium ion capacitors was summarized. Finally, the application prospects of metal single atoms in sodium ion capacitors were discussed.

As carbon peak and carbon neutrality become a global consensus,electrochemical energy storage technologies and related industries have been developing rapidly.The demand for electrode materials is also increasing steadily.How to prepare high?performance anode materials with widely available and low?cost precursors has thus become a research hot spot both in China and abroad.Coal is the most promising precursor for anode materials because of its high carbon content,abundant reserves,and low price.In recent years,researchers have prepared various anode materials,such as amorphous carbon,graphite,carbon nanotubes, and graphene,from coal and studied their application in lithium?ion batteries in depth.This paper summarized the research progress of three typical coal?based carbon anode materials in lithium?ion batteries.Then, it reviewed their synthesis methods,optimization and modification,and electrochemical performance.Finally,the paper presented an outlook on the development and application of coal?based carbon anode materials.

As a clean and effective new energy, fuel cell is regarded as one of the most important energy technologies. Proton conduction in solids has attracted much interest because of its potential application in fuel cells. Metal⁃oxalate compounds constructed by metal ions and oxalate are a sense of inorganic⁃organic hybrid compounds, which have emerged as a new class of proton conductors because of their controllable structures and high chemical variety. We summarized the proton conduction properties of main group⁃oxalate compounds, transition metal⁃oxalate compounds and lanthanide metal⁃oxalate compounds, and their future development was prospected.

Polysiloxane, as an organic silicon polymer， can be chemically modified by block copolymerization. Because of its abundant raw materials and excellent properties of modified products, it has been extensively studied by scholars. In this paper, the research progress of polysiloxane block copolymers at home and abroad was reviewed. Some kind of polysiloxane block copolymers modified by polyurea, polyurethane, polyether, polyamide and polyimide were mainly introduced. Also, its performance and application were summarized, and the prospect of its application was forecasted.

Based on the computational fluid dynamics theory, the physical mixing modeling of highdensity polyethylene (HDPE) and polystyrene (PS) in a internal batch mixer was established. By using Fluent software, the process of the mixed polymer in the mixer with double rotor was studied. The results showed thatthe mixing efficiency and asymmetry of the flow field were improved when the twinrotor mixer rotated in higher speed. After a period of time, the single polymer volume fraction at each position reached steady in the extruder.

Three dimensional mixing characteristics of the kneading elements in a intermeshing corotating triscrew extruders were simulated. The mesh superposition technique (MST) and the CarreauBird flow model were employed in this simulation. The mixing mechanisms in the kneading elements were analyzed with the mixing evaluation parameters, such as maximal shear rate, mixing index, instantaneous and time averaged efficiencies, which were compared with those in the twin screw extruders. The results show that, in the same operating conditions, the maximal shear rate, mixing index, instantaneous and time averaged efficiencies of the triscrew extruders are bigger than those of the twin screw extruder. It shows that the triscrew extruder has better mixing efficiency than the twin screw extruder.

When the vibration of heat exchanger tube bundle is large induced by fluid, the collisions between the tube and baffle will take place at the maximum amplitude of the tube, which leads to tube fretting wear and damage. The transient finite element analysis of fluidinduced vibration response for a heat exchanger tube was employed with ANSYS software. On this basis, the phenomenon of random rubbing between the bezel and tube was studied due to the larger vibration amplitudes of the tube. The nonlinear dynamic response and vibration rules of the random collisions between the bezel and tube were calculated. The calculated results provide a theory of reference for the design of heat exchanger tube bundles.

For the BZ294 project, the completed pigging of subsea pipeline had been successfully carried out before putting into production. The selection of pig and calculation of technical parameters had been introduced and the biggest feature of pigging was to make maximum use of facilities and process of existing platforms to save labor cost and temporary devices. According to the practical experience, some issues of pigging operation need to be focused, and can be used for reference in the future similar project.

The structure and composition changes of residue and hydrotreated oils by fixed reactor under different temperatures were researched by NMR, elemental analysis and molecular weight determination, et al. The results show that the average molecular weight of the hydrotreated oils, mole fraction of aromatic carbon, total carbon numbers, total hydrogen numbers, fraction of aromatic carbon, aromatic carbon numbers, total ring numbers, and aromatic ring numbers decreased after the hydrotreating. Atom ratio of hydrogen to carbon gradually increased. Results suggested that heavy fractions are cracked to light fraction, degree of unsaturation decreased, and residue property is obviously improved after hydrotreating.

In the oil drilling process,the motions of the drill string is very complicated process,which exists longitudinal,horizontal and torsional vibrations and random impacts and rubs between the well wall and drillstring.The non-linear dynamics finite element model of the bottom hole assembly (BHA) system was established with considering random impacts and rubs between the well wall and drillstring,drill bit and the rock.The transient vertical-horizontal-torsional coupling vibrations of the BHA system were studied with finite element method (FEM).The rules of the vibration motions and mechanical properties in the BHA were found out.The calculated results provide the references to oil drill string design and optimization of the system.