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The effect of different service parameters on the current-carrying tribological properties of CF-Al₂O₃/Cu composites was investigated, and the damage behavior of the composites under different service parameters was probed. The purpose of this study is to provide a theoretical basis for the application of CF-Al₂O₃/Cu composites.

The composites were fabricated by internal oxidation combined with powder metallurgy. The current-carrying tribological properties of CF-Al₂O₃/Cu composites were investigated on an electrical damage test system at different loads and currents.

As the load increases, the wear mechanism of the composite changes from abrasive wear to delamination wear. As the current increases, the oxidation wear and arc erosion of the composites gradually intensified. Under the service parameters of 0–25 A and 30–40 N, the composite has relatively stable current-carrying tribological properties.

This paper could provide a theoretical basis for the practical application of CF-Al₂O₃/Cu composites.

Copper matrix composites are widely used in high-voltage switches, electrified railways and other electric friction fields. The purpose of this study is to improve its wear resistance and investigate the effect of hybrid carbon nanotubes (CNTs) and titanium diboride (TiB₂) particles reinforced copper matrix composites on electrical wear performance.

CNTs and TiB₂ particles were introduced into copper matrix simultaneously by powder metallurgy combined with electroless copper plating. Electrical wear performance of the composites was studied on self-made pin on disk electrical wear tester.

The results show that the friction coefficient and wear rate of (1CNTs–4TiB₂)/Cu composite are respectively reduced by 40% and 25.3%, compared with single TiB₂/Cu composites. The micron-sized TiB₂ particles can hinder the plastic deformation of composites, and bear part of the load to weaken the wear rate of composites. CNTs with the self-lubricating property can form lubricating layer to reduce the friction coefficient of composites.

This work can provide a design method for further improving the wear properties of TiB₂/Cu composites.

Digital finance has the transformative power to realise financial inclusion. However, evidence on the relationship between digital finance and poverty reduction remains limited. This study examines the mitigating effects of digital financial inclusion (DFI) on vulnerability to poverty in rural China, explores potential mechanisms at the micro-level, and investigates the external conditions for DFI to validate these effects.

Rural household data from the China Labour Force Dynamics Survey and the regional DFI index compiled by Peking University are used. The probit and mediation effect models are employed to assess the impacts of the DFI on vulnerability to poverty and explore its mechanisms, with an appropriate instrumental variable to mitigate potential endogeneity.

DFI can mitigate vulnerability to poverty in Chinese rural households. Specifically, both sub-indices – coverage breadth and depth of use – have a significant effect. Further analyses based on the mediation model show that improving agricultural productivity, stimulating entrepreneurial activities and promoting non-agricultural employment are the core mechanisms for alleviating poverty vulnerability. Heterogeneity analysis shows that DFI is pro-poor and benefits those who lack economic opportunities. Moreover, adequate endowment in rural households, such as production and human capital, is an external condition for digital finance to mitigate vulnerability to poverty.

This study is among the first to examine the vulnerability-mitigation effects from the perspective of digital finance development, relying on data from a large-scale, nationwide household survey and the regional DFI index. It also checks for the mechanisms and heterogeneity of the effects, which prove the effects can help balance efficiency and equity.

This study aims to solve the premature failure of the rubber stator due to wear, reduce the frictional resistance moment of the screw pump to solve the problem of a model of Daqing oilfield screw pump oil recovery system shutdown after the difficult start.

For the first time, the rotor surface of a screw pump was treated with dot-matrix texture to study the effect of dot matrix texture on the tribological performance of the stator-rotor friction subsets of screw pump. Reciprocating friction tests with different texture morphologies (S-shape, double tongue) and angular parameters (0°, 45° and 90°) were conducted at 10% of the texture area and pump silicone grease.

When point texture was added to the surface of the rotor sample, the friction coefficient and wear quantity of the sample were lower than those of the surface without texture treatment, and the double tongue 0° combination showed the best tribological properties. At this time, the average coefficient of friction and wear is reduced by 22.8% and 62%, 28.6% and 64.8%.

The introduction of texture can effectively improve the tribological performance of progressive screw pumps, and this paper provides important theoretical and experimental support for the design of progressive screw pumps in practical applications.