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Considering the current issues such as low integration, imprecise pressure adjustment, poor network communication performance, and lack of maintainability in traditional braking control system of autonomous-rail rapid tram, the paper introduces a new generation of electro-pneumatic braking control technology. In the electronic control section, the traditional braking control and pressure regulation modules are combined into an integrated electronic control unit. In the pressure regulation integrated module section, multiple functional valves such as pressure regulating valve, emergency solenoid valve, and remote relief valve are integrated into one module. This simplification of the air circuit layout optimizes space use and centralizes control functions. This electro-pneumatic braking control system employs a pressure regulating valve that has been fully verified by rail transit, coupled with a new pressure regulating algorithm of the electronic control unit, making pressure regulation more stable, with higher accuracy and fewer actions. Additionally, the application of dual Ethernet architecture enhances data transmission quantity and efficiency by several times compared to traditional CAN communication, considerably improving network communication capabilities and maintainability levels. The braking control system has completed ground combined test and third-party vehicle test, and has been installed and applied in the latest hydrogen energy autonomous-rail rapid tram, demonstrating excellent overall performance.

The electro-dynamic braking capacity of hydrogen-powered autonomous-rail rapid tram is severely limited by the state of charge (SOC) of the energy storage battery and the operational status of the hydrogen fuel cell. When the energy storage battery is near its full charge state and the hydrogen fuel cell continues to generate power, the storage battery is unable to store the electrical energy generated from electro-dynamic braking, leading to the failure of the electro-dynamic braking function. To maximize the electro-dynamic braking capacity of hydrogen-powered autonomous-rail rapid trams, this paper proposes an electro-dynamic braking control strategy based on pedal deceleration demand. It firstly calculates the total vehicle electro-dynamic braking force based on brake pedal stroke and load status. It then combines the current energy status of the storage system and the hydrogen fuel cell system to initiate a brake torque request to the traction system. It also calculates the electro-dynamic braking force corresponding to the deceleration required by the brake pedal stroke, optimizing the output of electro-dynamic braking force under different load, intermediate gear placement, and medium-low speed conditions. The test results show that with this electro-dynamic braking control strategy, the train fully exploits its electro-dynamic braking capacity under medium-low gear placement and medium-low speed working conditions in AW0 circumstances. It meets the design requirements for regenerative braking energy recovery of hydrogen-powered autonomous-rail rapid tram under the current electro-dynamic braking system architecture.

[Objective] In the context of a large number of rural labors migrating to cities and towns, clarifying the impact of labor transfer on the green production efficiency of grains for farming households has important policy implications in promoting the steady improvement of green production efficiency and promoting sustainable development of agricultural ecology.[Methods] Based on the survey data of 770 grain-producing farming households from Hubei and Henan Provinces, this study used the data envelopment analysis-slacks-based measure (DEA-SBM) model to calculate the green production efficiency of grains, and used the Tobit model to demonstrate the impact of labor transfer and technology extension on the green production efficiency of grains.[Results] The research showed that labor transfer had an inhibitory effect on the green production efficiency of grains for farming households in both the temporal and spatial dimensions. Government green technology extension measures could promote the improvement of green production efficiency of grains and effectively alleviate the negative impact of labor transfer on green production efficiency of grains. The mitigating effect of technology extension services on the green production efficiency of farming households was limited by the age and income of farmers. For young and high-income farmers, its mitigating effect is insignificant. [Conclusion] Therefore, we should improve the rural labor security mechanism, expand the promotion channels of green production technologies, and focus on the promotion of green production technology for older and low-income farming households, to promote the improvement of green production efficiency of grains and effectively speed up the process of high-quality agricultural development.

Experimental evidences at the relativistic heavy ion collisions (RHIC) and large hadron collider (LHC) have demonstrated the formation of quark gluon plasma (QGP) in ultra-relativistic heavy-ion collisions at a small baryon chemical potential, where the phase transition from hadronic matter to QGP is suggested to be a crossover from state-of-the-art lattice quantum chromodynamics (QCD) calculations. It has been conjectured that there is a first-order phase transition and a critical point at a finite μB region in the QCD phase diagram. This study reviewed recent progress in searching for the QCD critical point from RHIC-STAR experiments.

For development demands and characteristics of informatization of coal industry, the paper analyzed and compared private network solution and rent network solution mainly from adaptability, disaster tolerance, scheduling functions, security, voice quality and other aspects, and got conclusions that private network solution had significant advantages. It analyzed advantages of TD-SCDMA network solution specifically, and indicated that private network solution can solve current communication problems of coal industry more effectively and meet the needs of coal mine safe production and communication development.

How to improve the adoption of green control techniques by farmers under the trend of continuous labor outflow is of vital importance to ensure food safety and promote sustainable agricultural development in China. Previous studies focused on the impact of changes in the economic value perception caused by labor migration on the adoption of green control techniques by farmers. However, the potential contribution of health safety and ecological safety perceptions to the adoption of techniques has not been fully discussed. This article established a theoretical framework including 'labor migration-value perception-green control technology adoption'. Based on the field survey data of 712 rural households in Hubei and Jiangxi provinces, this study used the Ordered Probit model and linear regression model to investigate the impact of labor migration on farmers' adoption of green control techniques and its mechanism. The results showed that: First, labor migration had a positive impact on the farmers' adoption of green control techniques. The above conclusion was still valid after considering the possible endogeneity and measurement errors caused by missing variables. Second, the analysis of the mechanism found that the greater the proportion of migrant workers, the stronger the farmers' perception of the economic value of adopting green control techniques, and the stronger the perception of health safety and ecological safety brought to themselves and their families, thus promoting farmers to adopt green control techniques. The three intermediary effects accounted for 20.3%, 34.1%, and 24.0% of the total effect. Third, farmers' health, years of education, planting scale, technical training and technical subsidies also had a significant impact on farmers' adoption of green control techniques. Therefore, strengthening farmers' vocational training and agricultural technology training to improve their ability to participate, and relying on the government, enterprises, and new media to cultivate farmers' comprehensive technical awareness can be effective methods to promote and popularize green control techniques. [ABSTRACT FROM AUTHOR]

The effects of water-binder ratio, mortar-sand ratio, mineral admixtures and nano-materials on the properties of high-strength sleeve grouting material were studied. The results show that as the water-binder ratio decreases and the mortar-sand ratio increases, the initial and 30 -minute fluidity of the high -strength sleeve grouting material decrease, and the compressive strength of each age increases: the effect of graphene oxide to the fluidity of sleeve grouting material is the smallest, and the compressive strength is the most obvious. The optimized mix ratio of the high-strength sleeve grouting material is: the cementing material is composed of 85% cement +2% gypsum+3% fly ash +5% fine sinking beads +5% silica fume, the water-binder ratio is 0.08, and the mortar ratio is 1.86, the dosage of polycarboxylate water-reducing agent, HPMC, boric acid is 0.55%, 0.12%, 0.10% of the mass of the cementing material, and the graphene oxide dosage is 0.3%. At this time, the 56-day compressive strength of the prepared high-strength sleeve grouting material reached 141.62 MPa. [ABSTRACT FROM AUTHOR]

Polycarboxylate superplasticizer (KZJ -HP) with high workability was synthesized by radical polymerization of isobutyl alcohol polyoxyethylene ether (HPEG) with acrylic acid and polypropylene glycol diacrylate (PPD400DA) in the presence of initiator at 40-45 centigrade-then K12 and H7 are added and mixed evenly. The study showed that PPD400DA added in the reaction improved the properties of concrete significantly, and may be involved in the formation of double chain polymer. In addition-with K12 and H7 added, water retention,and cohesiveness of concrete are improved significantly. It has excellent workability-high water-reducing rate and simple use, can be applied to high-performance self -compacting concrete by simple compounding with retarder, and has been applied in practical engineering successfully. [ABSTRACT FROM AUTHOR]

Four welded H-beams with trapezoidal corrugated webs were tested according to the relating provisions of GB 50017--2003' Code for design of steel structures' to study their fatigue performance. The test investigated in particular how the results can be "affected by the crane girder installation deviation as regulated in GB 50278--2010 'Code for construction and acceptance of cranes installation engineering'. By adopting the ANSYS finite element method, it is attempted to prove the validity of the failure mode. Results of the test and finite element analysis show that, the fatigue life of welded H-beam with trapezoidal corrugated webs is higher than that of H-beam with conventional fiat web with regard to the H-beams with corrugated webs of a corrugation profile recommended in CECS 291:2011 'Technical specification for steel structures with corrugated webs for approval'. In fatigue design, it can be rendered as valid as steel members of class 3 and the stress concentration caused by the folding of the web corrugation and installation deviation as well as other constructing factors can be ignored. [ABSTRACT FROM AUTHOR]

The effect factor of extraction of tea polysaccharide was investigated with orthogonal test. The effects of extraction conditions on yield, purity of tea polysaccharide and cost of extraction were discussed. The results show that the optimum conditions for extracting tea polysaccharide from green tea are as follows: extraction time is 30 minutes with water at 95 degrees C, extraction times with chloroform is 3, extraction times with CH3COOC2H5 is 1 and concentration of alcohol is 60%.