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In this paper, we have proposed a gas turbine combined cycle with the integration of low-temperature thermal energy and methanol decomposition, and also investigated a principle of the cascade utilization of chemical exergy of fuel. Here, the combustion of methanol fuel is divided up into two steps: the methanol is decomposed into the syngas with hydrogen and carbon monoxide through recovering the low-temperature thermal energy from an intercooler of a gas turbine, and then the syngas is combusted with air, namely, the indirect combustion of methanol. As a result, the exergy destruction in the combustion of syngas is expected to be decreased by 7.5 percentage points of the input energy of cycle; at the same time, the low-temperature thermal energy is upgraded to the chemical energy of fuel, and the thermal efficiency of this gas turbine cycle is expected to be about 6 percent points higher than that of a conventionally combined cycle with intercooling at the turbine inlet temperature of 1300 °C and at a given overall pressure ratio of 15. The promising results obtained here indicated that this gas turbine combined cycle could simultaneously accomplish the decrease of exergy destruction in combustion and the upgrade of low-temperature thermal energy levels, leading to the effective utilization of clean syngas fuel and the recovery of low-temperature thermal energy in power system.

Abstract As one of the four major industrial raw materials in the world, natural rubber is closely related to the national economy and people’s livelihood. The analysis of natural rubber price and volatility can give hedging guidance to manufacturers and provide investors with uncertainty and risk information to reduce investment losses. To effectively analyses and forecast the natural rubber’s price and volatility, this paper constructed a hybrid model that integrated the bidirectional gated recurrent unit and variational mode decomposition for short-term prediction of the natural rubber futures on the Shanghai Futures Exchange. In data preprocessing period, time series is decomposed by variational mode decomposition to capture the tendency and mutability information. The bidirectional gated recurrent unit is introduced to return the one-day-ahead prediction of the closing price and 7-day volatility for the natural rubber futures. The experimental results demonstrated that: (a) variational mode decomposition is an effective method for time series analysis, which can capture the information closely related to the market fluctuations; (b) the bidirectional neural network structure can significantly improve the model performance both in terms of fitting performance and the trend prediction; (c) a correspondence was found between the predicted target, i.e., the price and volatility, and the intrinsic modes, which manifested as the impact of the long-term and short-term characteristics on the targets at different time-scales. With a change in the time scale of forecasting targets, it was found that there was some variation in matching degree between the forecasting target and the mode sub-sequences.

Abstract Although the “resource curse” hypothesis has been supported by many empirical studies focusing on the transnational and regional levels, there has always been a point of contention about the proper method of estimating and selecting natural resource indicators in literature. This paper proposes a mixed estimation method for panel data of 10 typical oil and gas resource-based cities in China from 1998 to 2015. The results show that resource industry agglomeration can mirror the distribution and dependence on the resource industry by location rather than by merely measuring the influence of the relative scale of resource extraction on economic growth. Using resource industry agglomeration as the main explanatory variable for regional economic growth verifies the resource curse hypothesis and shows the nonlinear characteristics of the negative correlation between resources and economic growth. Despite mostly similar indicator parameter estimates, marked differences exist in measured effects for material capital investments and technological innovation investments. The result of using resource industry agglomeration as the main explanatory variable is basically consistent with the economic theory and is more in line with observed reality than the alternative indicator. The research conclusions can provide evidence and data for index selection in the studies on the mediating effect of resource curse transmission and international comparison.

Abstract Fabricating flexible vanadium dioxide (VO2) films is a serious challenge towards commercial applications. In this work, we proposed a new strategy to directly deposit VO2 thermochromic films on flexible substrates by using Cr2O3 structural template layer, which can serve as growth template for low temperature (~300 °C) deposition of VO2 films. The obtained crystalline VO2 films on flexible substrates show significant phase transition properties with narrow hysteresis loops. Optical and electrical characterizations have indicated phase transition features of the flexible VO2 films, with an excellent solar modulation ability (~60% at 2500 nm) and a resistivity change over 2 orders of magnitude. Meanwhile, the flexible VO2 film exhibits narrow hysteresis loops during the phase transition process, and the hysteresis loop widths are less than 1 °C. Flexibility and stability of VO2 film in this work has been demonstrated by a designed bending test, which can maintain stable thermochromic performance after over 5000 bending cycles. This work provided a facile strategy to fabricate VO2 films on flexible substrates as flexible electronic devices.

Abstract The equivalent electrical resistance of a cell with plane parallel electrodes is described by a simple mathematical model. The limits of this model were determined experimentally. The relation between the overpotential at the edge and at the middle of the electrode is established. The causes of dendrite occurrence at the edge of the electrode in galvanostatic cadmium deposition are discussed.

Abstract The transition of energy structure to renewable energy is a social and systematic engineering that requires complex regional power interconnection as a support. Thus, an assessment of the economic viability of infrastructure investments for supporting such transmission expansion is crucial. This study presents a multi-regional power system optimization model to evaluate the potential economic benefits of infrastructure investments for the national inter-regional electricity network in China under various scenarios in the context of low-carbon transformation. Key factors influencing economic benefits are analyzed specifically and regulation barriers associated with inter-regional electricity trade are given particular attention. The results show that approximately 140 Giga Watt (GW) of infrastructure construction for the inter-regional electricity trade network is economically viable during the planning horizon. These new interconnections would lead to 250–440 billion RMB of economic benefits. Regional electricity trade barriers caused by imperfect market mechanisms have a negative impact on the economic benefits of transmission infrastructure investments, although they promote scale and utilization efficiency in the power sector of electricity-importing regions. Improving the national grid coordination mechanism to break the grid isolation between the State Grid Corporation of China and the China Southern Power Grid is crucial, because a large number of transmission lines connecting these two national-level power grids are economically viable.

The cyclohexanone-containing fullerene mono-adduct, abbreviated as CHOC60, was efficiently prepared through single-step Diels-Alder reaction with 2-(trimethylsilyloxy)-l,3-butadiene and fullerenes. After reduction and esterification, CHOC60 was further converted into cyclohexyl acetate functional fullerene mono-adduct, named as CHAC60, which showed excellent solubility in common organic solvents. P3HT-based bulk heterojunction organic solar cells (OSCs) were fabricated through a typical structure of ITO/PEDOT:PSS/P3HT:(CHOC60 or CHAC60)/Ca/Al. The composite ratios of P3HT and the fullerene derivatives were modified such as 1:0.5, 1:1 and 1:1.5 (w/w). The devices fabricated using CHOC60 or CHAC60 as acceptors achieved the power conversion efficiencies (PCEs) of 2.97% and 3.15%, respectively, which exhibited comparative photovoltaic performances with commercial PC61BM. Moreover, CHOC60-based devices significantly reduced the manufacturing cost by the simplified synthesis of CHOC60 with high yield and low fullerene consumption. The non-aromatic side chain radical CHOC60 and CHAC60 provide a new idea for the design of fullerene derivative acceptors.

Abstract Solar photovoltaic (PV) technology is widely regarded as a significant and sustainable renewable energy option to fight against climate change.Accordingly, it is important to explore the potential of greenhouse gases (GHGs) mitigation and temperature benefits by substituting PV-generated power for coal-fired electricity. This necessity becomes particularly clear given that China hascommitted itself to a carbon emissions peak around 2030. Based on an integrated energy-economy-environmental model and a simple climate response model, we reach the following conclusions: (1) By restraining the cumulative GHGs emissions space within 255 GtCO 2eq till 2050, PV solar promises to dominate GHGs mitigation, with the highest contribution reaching 64.67%. (2) Under the moderate emissions-control case, China will achieve its emissions peak target, with solar energy substitution relieving the nation׳s dependence on coal. (3) The highest radiative forcing and temperature benefits yieldedthrough replacing coal-generated power with solar power is around 20% and 11.05%, respectively. (4) Finally, it is not too costly to gain such benefits: at most, the accumulated economic cost would be 102.14 trillion Yuanuntil 2050, accounting for less than 3% of the accumulated GDP.