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The adsorption behavior and dispersing capability of hyperbranched phosphated polycarboxylate superplasticizers (PCEs) containing phosphate monoester and phosphate diester were investigated. The hyperbranched structures were constructed using a special monomer dimethylaminoethyl methacrylate (DMAMEA) to create the branches during the polymerization. Meanwhile, the polymer architectures were tailored by varying the content of phosphate monoester and phosphate diester in the backbone via free radical solution polymerization. In contrast to comb-like PCE, hyperbranched PCEs presented a weaker dispersion capability at w/c = 0.29, but with a lower water-to-cement ratio (w/c), the hyperbranched PCEs exhibited a better dispersion capability than the comb-like PCEs. The dynamic light scattering (DLS) and transmission electron microscope (TEM) analysis showed that the adsorption layer of hyperbranched PCEs were thicker than that of comb-like PCEs. A thicker adsorption layer thickness generated thinner diffusion water layer thickness. The increase of the free water amount due to the thinner water diffusion layer is the key mechanism for improving the dispersibility and decreasing the viscosity of cement paste. [ABSTRACT FROM AUTHOR]

An attractive approach for the preparation of spirocyclic benzofuran–furocoumarins has been developed through iodine-catalyzed cascade annulation of 4-hydroxycoumarins with aurones. The reaction involves Michael addition, iodination, and intramolecular nucleophilic substitution in a one-step process, and offers an efficient method for easy access to a series of valuable spirocyclic benzofuran–furocoumarins in good yields (up to 99%) with excellent stereoselectivity. Moreover, this unprecedented protocol provides several advantages, including readily available materials, an environmentally benign catalyst, a broad substrate scope, and a simple procedure. [ABSTRACT FROM AUTHOR]

In recent years, with the rapid development of Internet technology, the integration of platform economy and e-commerce has become a popular business model. Two-sided platforms have a specific impact on sales, customer experience and transaction efficiency of both sides. In the current severe situation caused by the coronavirus pandemic, both the traditional unilateral market platform and the emerging two-sided market platform are in urgent need of a change in operation mode to reduce the marketing cost. Inspired by the cooperation between Meituan, a two-sided platform, and WeChat, a social media platform, this paper investigates the two-sided platform's scalable decisions on when to cooperate and how to optimize the pricing and investment decisions. We analyze how the two-sided platform makes decisions by considering the changes of network externalities from the cooperation with the social network platform. Compared with the scenario of non-cooperation, we derive the conditions under which platform cooperation can increase demands and increase platforms' profits, and analyze how cooperation affects the optimal pricing strategies. We find that the cooperation leads to a larger demand and a higher total profit, but might lead to higher registration prices for the platform users. Furthermore, we adopt the Nash bargaining framework and introduce platform bargaining power parameters to obtain the optimal cooperation and sharing strategy. Finally, we show how to adjust the investment strategy of the two-sided platform under platform cooperation. [ABSTRACT FROM AUTHOR]

This study introduces a new regional feed-in tariff (FIT) pricing mechanism for solar photovoltaic (PV) energy in China, informed by real option (RO) theory and incorporating the increasing significance of tradable green certificate (TGC) policy revenues. The mechanism aims to balance government and consumer burdens with investor benefits. By factoring in additional income from green certificate sales, the study calculates the internal rate of return (IRR) to fall between 8 and 16% and uses a Monte Carlo simulation to determine optimal FITs for 30 Chinese provinces. These optimal FITs are then compared with current FITs, which are categorized by three types of solar resource regions, revealing that many current FITs are set within an inappropriate range and require adjustment. Additionally, the study observes minor differences in provincial FITs within six regional power grids, suggesting that setting FIT guide prices at the regional grid level is more practical than by solar resource regions. A sensitivity analysis examines the impact of green certificate prices, carbon prices, and technological advancements on the FIT for solar PV, comparing scenarios in a realistic environment versus a more favorable one. The results indicate that in a better environment—with higher TGC and carbon prices and encouraged corporate innovation—the FIT for solar PV is closer to the cost of coal-fired electricity, thus promoting grid parity. The study advocates for adjustments to the FIT mechanism, higher TGC and carbon prices, and the encouragement of innovation to enhance the competitiveness of solar PV energy in China's energy market. [ABSTRACT FROM AUTHOR]

The photovoltaic (PV) industry is an important developmental direction of the global new energy industry, and it is also a strategic emerging industry of China with an international competitive advantage. China’s PV industry has developed rapidly in recent years, and the new installed capacity of PV power generation has been ranked first in the world for 5 years. This achievement is inseparable from the support of national policy, especially the Feed-in Tariff (FIT) policy of solar PV power generation, which is a primary policy of the PV industry. This paper is a study of preference elicitation, whose goal was to identify the driving factors behind historical PV policy in China, according to the opinion of a panel of experts. On this basis, this paper proposes an integrated ANP-Entropy model to evaluate the FIT policy of China in three dimensions: environmental, energy, and economic (3E). Research results show that the environmental goal is still the most significant to the development of the PV industry in China, followed by the energy and economic goals, which account for 0.405, 0.358, and 0.237, respectively. Compared with the conventional studies on energy policy evaluations, this paper integrates subjective (Analytic Network Process) and objective (Entropy Weight Method) evaluations, which makes the evaluation results more reasonable and reliable. Additionally, the 3E evaluation index system and the ANP-Entropy model proposed in this paper are also applicable to the evaluation of other renewable energy policies. [ABSTRACT FROM AUTHOR]

Driven by the transformation of the energy structure, China's photovoltaic (PV) power generation industry has made remarkable achievements in recent years. However, there are more than 30 regions (cities/provinces) in China, and the economic, policy, technological, and the environmental conditions of each region are significantly different, which leads to a huge discrepancy in PV power generation efficiency. To address the imbalance in the development of PV industry, first, this paper employed the integrated fuzzy analytic hierarchy process–data envelopment analysis (FAHP–DEA) model to evaluate the PV power generation efficiency of 30 regions in China. Second, Tobit regression model was used to examine the effects of 9 potential influencing factors. Third, a concrete analysis was conducted, and discussion based on the efficiency rankings and regression results was made. Additionally, the FAHP–DEA model proposed in this study can also be applied to the efficiency evaluation issues of other types of renewable energy. [ABSTRACT FROM AUTHOR]

To investigate the damage fractal and energy dissipation of dolomite marble under blasting load, Dahongshan Copper Mine was selected as the test object and one-dimensional SHPB impact tests with different strain rates were carried out. The dynamic compressive strength, damage morphology, fractal fragmentation, and energy dissipation of the rock were analyzed. The results showed that the absorbed energy per unit volume and the crushing energy per unit mass of dolomite marble are closely related to the dynamic compressive strength. The fractal dimension D of dolomite marble increases with increasing strain rate, and the smaller the average block size of the rock, the degree of crushing deepens. In addition, as the incident energy increases, the crushing energy of the rock also increases, and the energy dissipation intensifies. Finally, after comparative analysis, the reasonable strain rate range is 68.14–77.61 s−1, and the reasonable specific energy absorption value range is 0.65–0.98 J/cm3. The fractal pattern of rock deformation and damage can be reasonably explained from the perspective of energy dissipation. [ABSTRACT FROM AUTHOR]

Municipal solid waste incineration (MSWI) fly ash can cause serious early volume expansion when stabilized and solidified by cementitious materials. Many pretreatment processes have been reported, such as alkali solution, milling and chelating etc. However, these processes may lead to second pollution or higher costs. This study proposed an original pretreatment process of MSWI fly ash, and investigated its effect on the immobilization efficiency by alkali-activated slag (AAS) cement. The possible reasons for volume instability were assumed and analyzed by gas chromatography, scanning electron microscopy, X-ray diffraction, hydrostatic testing and leaching tests. It was found that the 0.377 wt% of metallic aluminum is the main expansive source of volume expansion in early stage (within 24 h). Due to the amphoteric characteristic of Al, it is possible to eliminate it using either acid or alkaline. Considering the fact that alkali-activated system and the fly ash were both alkaline, this study chose water immersion to pre-treat the fly ash, aiming to avoid the possible neutralization process of acid treatment and the entrained extra alkali component of alkali treatment, which may greatly affect many characteristics of alkali-activated slag. After pretreatment, the solidified specimens showed lower water demand (with a water to cement ratio of merely 0.27) and higher compressive strength due to the refined and smoothed particles. The volume expansive rate was greatly reduced, giving the better volumetric stability and encapsulation rate. Up to 90% MSWI fly ash-added solidified bodies feature a volume expansive rate of less than 0.09%. The alkali-activated slag pastes can effectively immobilize up to 70% treated fly ash with the leaching rate of solidified particles lower than the limits recommended by Chinese standard, Identification for extraction toxicity (CSEPA GB 5085.1, 2007). Therefore, the pretreatment process is easy to operate and is a promising way to increase the immobilization efficiency of alkali-activated slag cement. • Taking advantage of MSWI fly ash's own alkalinity to reduce volume expansion. • The pretreatment process won't produce waste water which brings second pollution. • Solidified bodies gained early and long-term volume stability after pretreatment. • The effective immobilization amount increased up to 70% after pretreatment. • AAS shows better potential than PC in immobilizing MSWI fly ash. [ABSTRACT FROM AUTHOR]

Technical innovation promotes manufacturing industry to achieve energy conservation and emission reduction. As an area that accounts for more than 50% of China's economy, east region of China has taken the lead in developing and focusing on promoting industrial upgrading based on the innovation-driven development strategy. The potential solution of transforming China's manufacturing industry is to enhance the capability of independent innovation by increasing the investment in research and development. Research on the sustainable development capacity of east region manufacturing industry has been giving important guidance for upgrading the manufacturing industry all over China. However, few studies explore the research and development effect on the energy-saving potential of manufacturing at the regional level, and study the individual dynamic behavior to reflect industry heterogeneity. In this paper, the dynamic panel data research method is employed to explore the influence of the research and development on energy conservation while introducing macroeconomic variables. Additionally, block bootstrap-based scenario analysis is employed to predict the energy conservation of manufacturing in east region in 2020 and 2025 based on historical annual data from 1990 to 2016. Compared with the business-as-usual scenario, the advanced scenario could reduce the energy demand of 427.53Mtce and 1066.28 million tons of coal equivalent in 2020 and 2025, respectively. The results indicate that there is much room for improvement in terms of the energy efficiency for China's east region. • We investigate the effect of R&D on energy conservation potential in eastern China. • The modeling framework is designed based on dynamic panel data model. • A block bootstrap based scenario analysis is employed to this study. • We provide long-term perspective for energy conservation potential prediction. [ABSTRACT FROM AUTHOR]

Drying shrinkage of alkali-activated slag concrete (AASC) is significantly greater than that of concrete made with ordinary Portland cement (OPC). It limits the large-scale application of AASC in field engineering. This study investigates the effect of early age-curing methods, including water curing, curing in elevated-temperature water, and CO2 curing, on drying shrinkage of AASC. Scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric (TG-DTG), and mercury intrusion porosimetry (MIP) were carried out to analyze the composition and microstructure of hydration products, to provide deeper understanding of drying shrinkage of AASC. The results show that water curing decreased drying shrinkage of both C30 and C50 AASC moderately compared to air curing, while it was more effective for C30 AASC. Curing in water of elevated temperature and CO2 curing were very beneficial to mitigate drying shrinkage of AASC. Heat curing decreased drying shrinkage of AASC up to 80%. SEM and TG-DTG results show that denser microstructure formed because of the accelerated hydration, resulting in lower porosity and lower proportion of pores smaller than 25 nm that contributed to the reduction of drying shrinkage. In addition, under high-temperature curing, most autogenous shrinkage of AASC occurred in the first few days because hydration was accelerated. After measurement of drying shrinkage was started, recorded autogenous shrinkage of AASC cured in elevated-temperature water should be much less than that of AASC cured at normal temperature. It is another important reason for the reduction of drying shrinkage. Carbonation occurring in the CO2 curing period led to the decalcification of C-(A)-S-H gel; it coarsened the pore-size distribution and decreased the total porosity. Therefore, drying shrinkage of C30 and C50 AASC was declined by 49% and 53% respectively. [ABSTRACT FROM AUTHOR]