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The objective of this research was to develop a solution for the deterioration effect on the high-temperature rutting performance and water stability of SMC. This research proposed a method for designing an SMC normal temperature modified asphalt mixture based on the existing findings, experimental research and the performance balance. First, the power function curve model of the aggregate gradation was put forward. The 0.075 mm, 4.75 mm and nominal maximum particle size were the key points of the aggregate gradation, and their passing rate was about 6%, 30%, and 95% respectively. Then, on the basis of the quadratic curve model, a method for determination of the optimum asphalt aggregate ratio of SMC normal temperature modified asphalt mixture was put forward, considering the skeleton-density structure. Last, rutting tests, small beam bending tests, freeze-thaw split tests, permeability coefficient tests, texture depth tests and pavement roughness tests were conducted, and the test results all met the performance requirements of the specifications for the construction of highway asphalt pavement in China perfectly, especially the high-temperature and water stability properties, which indicated that the design method for SMC normal temperature modified asphalt mixtures based on performance balance presented in this paper was reasonable and practical. [ABSTRACT FROM AUTHOR]

Geothermal fields emit remarkable amounts of mercury (Hg) to the environment. To address the source, fate and geochemical cycling of Hg in geothermal fields, we investigated Hg concentrations and isotopic compositions of hot spring water and fumarole gases from Rehai and Dagejia in SW‐China. Elevated Hg concentrations in fumarole gases (10.0–167 ng m−3) and hot spring water (3.44–84.5 ng L−1) were observed, suggesting that both geothermal fields are of environmental concern. The variation in Δ199Hg (−0.06 to 0.23‰) and Δ200Hg (−0.09 to 0.19‰) in hot spring water supports Hg likely originating from endogenous volcanic degassing and/or rainwater. Negative and nearly zero Δ199Hg in fumarole gases (−0.32 to 0.03‰) supports volcanic degassing and background atmosphere origin. The ranges of δ202Hg in fumarole gases (−0.74 to 0.59‰) and hot spring water (−1.29 to 0.52‰) could reflect limited fluids boiling in geothermal fields. This study, thus, fills an important knowledge gap regarding Hg global cycling. Plain Language Summary: A large amount of mercury (Hg) is emitted into the atmosphere through geothermal activities. A knowledge gap exists regarding the source, fate and geochemical cycling of Hg in geothermal fields. Here, we studied Hg concentrations and isotopic compositions in hot spring water and fumarole gases from two large geothermal fields in SW‐China. Our results support that the two fields received Hg from endogenous volcanic degassing and rainwater. Deep magma chambers acted as heat sources, triggering fluid circulation in geothermal areas and entraining Hg from rainwater into geothermal systems. Key Points: Rehai and Dagejia geothermal fields are likely of local environmental concern regarding Hg emissionMercury isotopic ratios evidence that geothermal fields could receive Hg from endogenous volcanic degassing and rainwaterGeothermal fluid boiling is not common in geothermal fields in SW‐China [ABSTRACT FROM AUTHOR]

Consumption is evidenced to play an increasing significant role accompanied by economic transition in China. Carbon emissions caused by consumption are becoming an important growth point of carbon emissions. The size of China's middle-income groups is growing and is expected to reach 60 % of the population in 2035. However, the amount of indirect carbon emissions from household consumption (ICEHCs) of middle-income groups and the effects of their drivers have not been quantitatively assessed. In response, this paper adopts input-output tables to calculate urban-rural middle-income groups' ICEHCs from 2012 to 2018, and uses structural decomposition analysis to determine the effects of drivers and sectors. Results are as follows: Urban-rural middle-income groups' ICEHCs in the Yangtze River Economic Belt (YREB) are increasing and its differences are significant, and present a spatial pattern of high in the eastern region while low in the western region. S22 (Production and Supply of Electric Power, Steam and Hot Water) becomes the main sector of carbon emissions, which accounts for about 70.00 % of the total middle-income groups' ICEHCs in 2018. Consumption pattern is the predominant driver for promoting urban-rural middle-income groups' ICEHCs, whereas production structure is the predominant restraining driver. • Middle-income groups' ICEHCs are calculated and S22 is the main sector. • The drivers and main sectoral sources of household energy consumption are explored. • Consumption pattern is the predominant driver for promoting ICEHCs. [ABSTRACT FROM AUTHOR]

The efficient utilization of solar energy significantly contributes to energy efficiency in buildings. Solar photovoltaic thermal (PVT) heat pumps, a hybrid of photovoltaic and solar-assisted heat pumps, have demonstrated a significant development trend due to their multi-generational capacity for heating, power, and cooling with reliable operational performance. This research work presents and investigates a single-stage compression PVT heat pump system, along with the operation principle of the system's heating and power co-generation throughout the winter and transitional season. The construction of the testing facility, data reduction, error analysis, and performance evaluation indices of the system are all explained theoretically. A continuous experiment research project focusing on system heating and power performance was carried out in Dalian during the transition season (November in this study) and winter season (December in this study) as part of our investigation into the potential uses for space heating, residential hot water, and power supply in northern China. The findings of the experimental research demonstrate that the proposed system can generate electricity and heat at high efficiency during the winter and transitional seasons, with long-term stable performance. The system's average heating COPt is 5 during the transitional season and 4.4 during the winter season. Meanwhile, the average photovoltaic power efficiency under both weather conditions is 11.9% and 10.2%, with a peak value of 15.7% and 12.0%, respectively. Additionally, the system compression ratio's variation range is 2 to 3.88, which is lower than the standard heat pump system. As a result, the entire system heating operating process remains constant. [ABSTRACT FROM AUTHOR]

The Ormosia hosiei is a secondary protected wild plant in China, and its seed has a hardness rate of 86%. To explore the characteristics of the hard seed and the difference in seed vigor between hard seeds and the non-hard seeds of O. hosiei, the water absorption characteristics, germination characteristics, seed coat structure, seed coat permeability, enzyme activity, and main biochemical substances of the O. hosiei seeds were determined. The results showed that the hard and dense seed coat is the main obstacle to absorbing water of O. hosiei seeds; the main reason is that the seed coat is composed of cuticle, palisade cells, and thick-walled cells with impermeability. Hot water treatment can soften the seed coat and remove wax and grease from the seed coat, and concentrated sulfuric acid treatment can corrode the local seed coat and break the barrier of cuticle and palisade tissue. The effectiveness of concentrated sulfuric acid to break the dormancy of O. hosiei hard seeds is better than that of hot water treatment, but the damage to the seed coat is larger and irreversible. The germination, germination index, root activity, TTCH content, and SOD activity of the hard seeds were higher than those of the non-hard seeds, but the SSC, conductivity value, and MDA content were lower than those of the non-hard seeds. [ABSTRACT FROM AUTHOR]

The water immersion residual coal tend to happen spontaneous combustion accidents after mining the coal seam. For exploring the oxidative re-ignition properties of high-temperature oxidized water-impregnated long-flame coal, the thermal evolution law toward each pre-oxidized coal soaked in water under varying heating rates (Rh) (5, 10, 15°C/min) has been analyzed by thermogravimetric differential scanning calorimetry (TG-DSC). The findings are as follows: the DTG at the critical temperature (T1) and maximum weight loss temperature (T5) increases, the activation energy (E) decreases, and the heat output increases (maximum 6391J/g) with the rising Rh. The violent oxidated reaction process of coal samples has been delayed as the Rh was 10°C/min. The water-immersed coal sample (I200) contains more free water on the surface, and the maximum (0.45 mW/mg) and total (178.8 J/g) heat absorption of are higher. Oxidation at 200°C and soaking in water (O200I200) reduced the ignition point temperature (minimum 399°C) and E (minimum 18.5 kJ/mol), and increased the total heat release (maximum 323 J/g) making it easier to oxidize and re-ignite. Under the same Rh, the oxidation and combustion traits of each pre-oxidized water-immersed coal (PWIC) remained unchanged. Reducing the Rh can effectively prevent spontaneous combustion of high-temperature oxidized water-soaked coal in shallow-buried and short-distance coal seams in northwest of China. [ABSTRACT FROM AUTHOR]

Poplar is a common tree species that is extensively cultivated in China, and its density is relatively low. The low density of poplar results in low mechanical properties, which restrict its application range. However, the density of wood can be increased by compressing the porous structure in the transverse direction. Before compression, the wood needs to be softened from a rigid state to a thermoplastic flow state. After compression, the compressive deformation needs to be fixed. The hot water pretreatment and heat post-treatment is by far the most convenient and environment-friendly way for the manufacture of the densified wood. This study presents the mechanical properties of densified poplar by hot water pretreatment with different compression ratio and thermal modification time, and explores the engineering application potential of densified poplar as wooden dowel to connect timber members instead of steel dowel. [ABSTRACT FROM AUTHOR]

Under the influence of climate alteration and human activities, the hydrological regime of rivers is changing dramatically, which has become a hot spot for water environment research. In this study, we quantitatively assessed the degree of hydrological variability of the Jialing River and the contribution of climate alteration and human activities to hydrological alterations using the ecohydrological indicator range of alteration (IHA-RVA) method and Budyko hypothesis formulations. The results showed that (1) The average annual runoff and the precipitation of Jialing River showed a decreasing trend, the potential evapotranspiration showed an increasing trend. (2) Compared with before the hydrological situation changed, the degree of alteration in the annual extreme streamflow is 31%, which is a low degree of alteration; the degree of alteration in monthly streamflow, annual extreme flow magnitude, extreme flow ephemeris, and streamflow alteration frequency are 51%, 43%, 54%, and 64% respectively, which are all moderate degrees of alteration; the overall hydrological alteration is 50%, which belongs to moderate alteration. (3) The contribution of precipitation, potential evapotranspiration, and human activities to the runoff alteration is 61%, − 16%, and 55%, respectively. This study provides corresponding references for ecological restoration and sustainable development of the Yangtze River Basin in China. [ABSTRACT FROM AUTHOR]

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Hydrogeochemical changes in association with earthquakes are considered as a potential means of identifying earthquake precursors. The Xianshuihe fault zone (XSHF) is considered one of the most active seismic fault zones in China; 43 hot springs were sampled and analysed in the laboratory for major elements, silica, stable isotopes (δD and δ18O) and strontium isotopes were investigated from 2008 to 2021. The meteoric water acted as the primary water source of the hot spring in the XSHF, and recharged elevations ranged from 1.9 to 4.8 km. The geothermometers method was used to estimate the region of thermal storage temperature and its temperature between 8 and 142 °C. And the circulation depth ranged from 0.1 to 6.9 km. Most of the hot spring water was immature water with a weak degree of water-rock reaction. However, the degree of water-rock reaction and the depth of hot spring water circulation were high in part of the Kangding and Daufu segments, which also had the highest reservoir temperature and the most frequent strong earthquakes. Temporal variations of hydrogeochemical showed that Na+, Cl− and SO42− decreased obviously following the 12 May 2008 Wenchuan Ms8.0 and existed abnormal value fluctuations from the 20 April 2013 Lushan Ms7.0 to 22 November 2014 Kangding Ms6.3 occurred and after 20 July 2017 returned to the normal levels. And the ion concentrations in hot springs increased by 5% to 35% three months before 22 November 2014 Kangding Ms6.3 with the obvious precursor anomaly. Hydrogeochemical anomalies could be useful for predicting an earthquake in the study area. [ABSTRACT FROM AUTHOR]