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Objective Evaluation methods for conventional equipment health grade tend to be one-sided and limited in scope. There is a need to develop an evaluation method tailored to the stringent safety demands of signaling systems. The goal is to control the full lifecycle costs, extend the system longevity, and address the general pain point of financial constraints faced by most urban metro constructions at present. Method Starting with several conventional equipment health grade evaluation methods, a comprehensive evaluation model is constructed. The equipment historical performance is evaluated by annual average repair rate data, the equipment service life is evaluated by comparing the equipment designed theoretical lifespan with actual online service time, and current equipment conditions by field survey of actual working conditions and laboratory sampling test results. By integrating these multi-dimensional data points, a comprehensive evaluation method for signaling system safety equipment is developed. Result & Conclusion The practical application of this evaluation method, supported by data statistics and analysis, produces concrete evaluation conclusions and corresponding maintenance recommendations. This validates the feasibility of the comprehensive equipment health grade evaluation method. At the same time, the application of this method enables an in-depth inspection of signaling systems based on service life prolonging requirements, facilitates the formulation of targeted preventive maintenance measures, and proposes plans for future improvements in digitalization and intelligent technology.

Under the guidance of China′s ecological civilization policy, while the utilization of industrial water has been improved, the total wastewater discharge still cannot be neglected. Therefore, zero liquid discharge (ZLD) of industrial wastewater has been highlighted as an essential path to realize the utilization of waste. However, waste salt and high-concentration brine are generated during the zero liquid discharge process. The disposal of waste salt is challenging in China, and there is little progress in its utilization, which has become one of the bottlenecks restricting the ZLD process. Compared with the conventional process employing pure salt, the ionic membrane-based Chlor-alkali system using industrial waste salt would be influenced by the presence of impurity components in the feed, which may lead to new challenges such as membrane fouling. To address the limitations, this review paper will introduce the principle and process of recycling waste salt in the ionic membrane-based Chlor-alkali industry, discuss the process mechanism and characterization methods of membrane fouling caused by anions/cations and dissolved organic matter, put forward reasonable countermeasures such as feed control, membrane cleaning and process optimization, and explore future research prospects on adjustment of the feed water quality and the development of high-performance cation exchange membranes. This review aims to promote the development and application of waste salt recycling technology in the process of zero liquid discharge of industrial wastewater.

Ensuring the safety of rural drinking water is a basic component of poverty alleviation in China. Studying the strategy for ensuring drinking water safety in areas that were lifted out of poverty is important for consolidating poverty alleviation achievements and promoting rural revitalization in China. In this article, we study the current situation and problems of rural drinking water in poverty alleviation areas, analyze the causes of the problems, and propose strategic objectives and pathways from the aspects of engineering, policy, and mechanism. To guarantee the safety supply of rural drinking water in poverty alleviation areas, we suggest that the drinking water safety policies in these areas should remain stable and constant, the sanitary standards of drinking water in rural areas should be optimized to meet those in urban areas, and a long-term policy focusing on water price should be established for rural water supply.

[Objective] Evaluation methods for conventional equipment health grade tend to be one-sided and limited in scope. There is a need to develop an evaluation method tailored to the stringent safety demands of signaling systems. The goal is to control the full lifecycle costs, extend the system longevity, and address the general pain point of financial constraints faced by most urban metro constructions at present. [Method] Starting with several conventional equipment health grade evaluation methods, a comprehensive evaluation model is constructed. The equipment historical performance is evaluated by annual average repair rate data, the equipment service life is evaluated by comparing the equipment designed theoretical lifespan with actual online service time, and current equipment conditions by field survey of actual working conditions and laboratory sampling test results. By integrating these multi-dimensional data points, a comprehensive evaluation method for signaling system safety equipment is developed. [Result & Conclusion] The practical application of this evaluation method, supported by data statistics and analysis, produces concrete evaluation conclusions and corresponding maintenance recommendations. This validates the feasibility of the comprehensive equipment health grade evaluation method. At the same time, the application of this method enables an in-depth inspection of signaling systems based on service life prolonging requirements, facilitates the formulation of targeted preventive maintenance measures, and proposes plans for future improvements in digitalization and intelligent technology. [ABSTRACT FROM AUTHOR]

Global navigation satellite system occultation sounder (GNOS) Fengyun-3C was launched successfully on September 23, 2013, which carried GPS/BDS receiver for the first time. This provides the convenience to study the enhancement results of low earth orbiter satellite (LEO) to BDS precise orbit determination (POD). First the data characteristic and code observation noise of GNOS are analyzed. Then the enhancement experiments in the case of global and regional ground observation stations layout are processed with four POD schemes: BDS single system, GPS/BDS double system, BDS single system with GNOS observations, GPS/BDS double system with GNOS observations. The precision of BDS orbits and clocks are compared via overlapping arcs. Results show that in the case of global station layout the along directional precision of GEO satellite has the biggest improvement, with the improvement percentage 60%. Then the precision of cross direction and the along direction of remaining satellites shows the second biggest improvement. The orbit precision of BDS-only POD in part of observation arcs some satellite even suffers a slight decline. The root mean square (RMS) of overlapping clock difference of visible arcs in GPS/BDS POD experiments improves by 0.1ns level. As to the experiments of regional station layout with 7 ground stations, the orbit and clock overlapping precision and orbit predicting precision are analyzed. Results show that the predicting precision of BDS GEO satellites in the along direction improves by 85%. The remaining also has a substantial improvement, with the average percentage 21.7%. RMS of overlapping clock difference of visible arcs improves by 0.5ns level.