Research on Prediction Model of Prestress Loss of Anchor Cable in Soil-Rock Dual-Structure Slope

The establishment of the prestressed cable loss prediction model is a difficult problem faced by the popularization and use. This article aims at the problem of the loss of anchor cable prestress over time in the soil-rock dual-structure slope. We relied on the soil-rock dual-structure slope treatment project of section K5 + 220-K5 + 770 of Jiangwen Expressway and monitored the prestress loss of the anchor cable in the slope through the anchor cable meter with built-in vibrating wire sensor. Using regression analysis and segmented modelling methods, we established a comprehensive mathematical improvement model, analyzed the applicability of the improved model, and obtained the error range, 0.04%–8.9%. This work offers a new approach for predicting anchor cable prestress loss, which has certain practical value for the use of prestressed anchor cables.

Turbulence Calculations of a Dual-Structure Oxygen Lance for Converter Based on Hydrodynamics

The oxygen lance is a piece of special equipment in the converter steelmaking process for blowing oxygen into the molten steel. After more than 80 years of development, the structure and function of the oxygen lance have undergone many changes. In this paper, based on the theory of hydrodynamics, the jet behavior characteristics of a dual-structure oxygen lance for the converter are determined and optimized by CFD simulations and compared with those of the traditional-structure oxygen lance. The research results show that multiple jets deflect to the central axis of the oxygen lance during movement and the inclination angle of the nozzle holes influences the jet deflection. A decrease in the nozzle hole angle results in an increase in the mutual suction between the streams. With the increasing flow rate through the large holes in the new dual-structure oxygen lance, the dynamic radial pressure increases at the middle of the jet. The jet flow characteristics of the new dual-structure oxygen lance are better than those of the traditional oxygen lance. Its impact on the molten pool includes greater momentum, a larger impact area, and a more uniform and powerful stirring of the molten pool. A nozzle angle of 14° combined with a flow rate ratio of 65% and a nozzle angle of 17° combined with a flow rate ratio of 35% are the optimal parameters for the new dual-structure oxygen lance.

From Russia to Palestine via Poland: The Shifting Centre of Interwar Labour Zionism

Under British rule Palestine gradually emerged as the new centre of Zionism. The Zionist centre shifted from Eastern and Central Europe to Mandatory Palestine through a combined process of mass migration and the creation of transnational institutions. By exploring the building of transnational institutions in the 1920's, this article shows how the Labour Zionist leadership in Palestine turned its communities of origin in Eastern Europe into their supporters. With the rapid decline of the former Russian centre under the communist dictatorship, independent Poland emerged as a new centre of Zionism and the labour movement outside Palestine. The two new centres were connected by a dual structure, with Poland as the demographic centre and Palestine the political-cultural one. The dual-centre structure was unique to Labour Zionism, building a mass movement between Eastern Europe and Palestine in the 1930s, and leading ultimately to the transition of power from liberal Zionism to a Labour hegemony.

Research on Urban and Rural Involvement in Smart Elderly Services

This article aims to overcome the challenges faced by traditional elderly care services in China and discuss the development opportunities of smart elderly care services in urban and rural areas. Additionally, seek feasible countermeasures based on the basic ideas of smart elderly care to promote the transformation of urban and rural elderly care services to smart and intelligent. Therefore, we can bridge the gap between urban and rural areas, break the urban-rural dual structure, and encourage cities and villages to share the benefits of reform and development.