Theory of Critical Phenomena with Long-Range Temporal Interaction

We develop a systematic theory for the critical phenomena with memory in all spatial dimensions, including $dd_c$, the upper critical dimension. We show that the Hamiltonian plays a unique role in dynamics and the dimensional constant $\mathfrak{d}_t$ that embodies the intimate relationship between space and time is the fundamental ingredient of the theory. However, its value varies with the space dimension continuously and vanishes exactly at $d=4$, reflecting reasonably the variation of the amount of the temporal dimension that is transferred to the spatial one with the strength of fluctuations. Such variations of the temporal dimension save all scaling laws though the fluctuation-dissipation theorem is violated. Various new universality classes emerge.Comment: 32 pages, 1 figure. Version 2: 41 pages, 1 figure. Clarify the origin of the memor

Acceptor plane expansion enhances horizontal orientation of thermally activated delayed fluorescence emitters.

Manipulating orientation of organic emitters remains a formidable challenge in organic light-emitting diodes (OLEDs). Here, expansion of the acceptor plane of thermally activated delayed fluorescence (TADF) emitters was demonstrated to selectively modulate emitting dipole orientation. Two proof-of-the-concept molecules, PXZPyPM and PXZTAZPM, were prepared by introducing a planar 2-phenylpyridine or 2,4,6-triphenyl-1,3,5-triazine substituent into a prototypical molecule (PXZPM) bearing a pyrimidine core and two phenoxazine donors. This design approach suppressed the influence of substituents on electronic structures and associated optoelectronic properties. Accordingly, PXZPyPM and PXZTAZPM preserved almost the same excited states and similar emission characteristics as PXZPM. The expanded acceptor plane of PXZPyPM and PXZTAZPM resulted in a 15 to 18% increase in horizontal ratios of emitting dipole orientation. PXZPyPM supported its green device exhibiting an external quantum efficiency of 33.9% and a power efficiency of 118.9 lumen per watt, competitive with the most efficient green TADF OLEDs reported so far

Development of cylindrical laminated methanol steam reforming microreactor with cascading metal foams as catalyst support

In this study, the cascading metal foams were used as catalyst supports for constructing a new type of cylindrical laminated methanol steam reforming microreactor for hydrogen production. The two-layer impregnation method was used to load the Cu/Zn/Al/Zr catalysts, and the ultrasonic vibration method was then employed to investigate the loading performance of metal foams with different types and thicknesses. Furthermore, the effect of the type of catalyst placement, pores per inch (PPI) and foam type on the performance of methanol steam reforming microreactor was studied by varying the gas hourly space velocity (GHSV) and reaction temperature. Compared with two other types of catalyst placement studied, the microreactor containing catalyst-loaded metal foams without clearance cascading (3 × 2) showed the highest hydrogen production performance. When the PPI of the metal foam was increased from 50 to 100, both the methanol conversion and the H2 flow rate gradually increased. Our results also showed that a microreactor with Cu foam as a catalyst support exhibits increased hydrogen production and higher stability than those of a microreactor with Ni foam

Total Factor Productivity and High-Quality Economic Development: A Theoretical and Empirical Analysis of the Yangtze River Economic Belt, China

This paper focuses on the total factor productivity (TFP) and high-quality economic development in China by examining 11 Chinese provinces and cities in the Yangtze River Economic Belt from 2007 to 2018. We use the Solow residual method to calculate the TFP growth rate of the 11 provinces and cities. Based on the panel data, we have analyzed the influencing factors of TFP theoretically and empirically from the overall region and upstream region, and midstream region and downstream region, respectively. The regression results show that: (1) The whole characteristics generally show the TFP growth trend of the upstream region, midstream region and downstream region are consistent with that of the overall region, and the growth rate of TFP slows down gradually. Meanwhile the differences in TFP growth between the upstream region, midstream region and downstream region show an increase at first and then a decrease. (2) Regarding the influencing factors, there are differences in the direction and extent of the impact of each factor such as the level of openness, R&D investment, industrial structure, government expenditure and human capital on the TFP of the overall region, upstream region, midstream region and downstream region. (3) Based on the results of the theoretical and empirical analysis, we have proposed a series of measures for the sustainable high-quality development of the Yangtze River Economic Belt

Critical Exponents and Universality for Fractal Time Processes above the Upper Critical Dimensionality

We study the critical behaviors of systems undergoing fractal time processes above the upper critical dimension. We derive a set of novel critical exponents, irrespective of the order of the fractional time derivative or the particular form of interaction in the Hamiltonian. For fractal time processes, we not only discover new universality classes with a dimensional constant but also decompose the dangerous irrelevant variables to obtain corrections for critical dynamic behavior and static critical properties. This contrasts with the traditional theory of critical phenomena, which posits that static critical exponents are unrelated to the dynamical processes. Simulations of the Landau–Ginzburg model for fractal time processes and the Ising model with temporal long-range interactions both show good agreement with our set of critical exponents, verifying its universality. The discovery of this new universality class provides a method for examining whether a system is undergoing a fractal time process near the critical point

Carbon-Reduction, Green Finance, and High-Quality Economic Development: A Case of China

Development that is eco-friendly, coordinated, sustainable, and of the highest caliber is crucial to China’s modernization. Based on the Cobb–Douglas production function and environmental Kuznets curve analysis, this paper investigates the link between green finance and the reduction of carbon emissions and high-quality economic development, then puts forward the hypothesis that green finance promotes high-quality economic development, and carbon emission reduction effect is its important transmission mechanism. This paper applies the bidirectional fixed effect model to a panel dataset of 30 Chinese provinces, cities, and autonomous regions from 2008 to 2019 to conduct an empirical test. The empirical results show that: (1) Green finance has a significant role in promoting high-quality economic development, which has passed the robustness test and has regional heterogeneity. (2) The growth of green financing reduces carbon emissions, which encourages high-quality development. (3) A positive spatial spillover effect results from the promotion of green finance to high-quality economic development. Given the aforementioned findings, this paper makes policy recommendations regarding how green financing, carbon emission reduction, and high-quality economic development might work together to support green development

Fiscal Decentralization, Pollution and China’s Tourism Revenue

This paper focuses on the role of local governments in the development of tourism in China by examining 30 Chinese provinces from 2000 to 2018. The results of empirical research show that fiscal decentralization in China provides local governments with incentives for the development of high pollution industries and of large state-owned enterprises, which do not help the sustainable development of tourism. In addition, there is an “inverted U-shaped” relationship between pollution level and tourism development. Although the growth of China’s tourism industry is pollution-based currently, tourism revenue is considered to decline once a threshold is reached. The competition from local governments for foreign investment is conducive to the improvement of environmental quality and increase in tourism revenue. Based on this, we have proposed a series of sustainable tourism development measures

The Spatial Spillover Effect of Clean Energy Development on Economic Development: A Case of Theoretical and Empirical Analyses from China

Does clean energy development (CED) have a spatial spillover effect on economic growth (EG)? Using the panel data of 30 provincial administrative units from 2000 to 2019 in China, this study empirically investigates the spatial spillover effect of CED on EG. From the perspective of the supply side rather than the consumption side, using the spatial Durbin model (SDM), the study finds that CED does not have a significant impact on EG, while there is an apparent positive spillover effect of CED on EG in China, meaning that CED in one province can boost EG in the surrounding provinces. Theoretically, this paper provides a new perspective for studying the relationship between CED and EG. In practice, it provides a reference for further improving the government’s future energy policy

Measurement of Structural Loads Using a Novel MEMS Extrinsic Fabry–Perot Strain Sensor

In this paper, microelectromechanical systems (MEMS) technology was used to fabricate a novel extrinsic fiber Fabry–Perot (EFFP) strain sensor; this fiber sensor is applied to measure load with higher precision for a small structure. The sensor cavity consists of two Fabry–Perot (FP) cavity mirrors that are processed by surface micromachining and then fused and spliced together by the silicon–glass anode bonding process. The initial cavity length can be strictly controlled, and the excellent parallelism of the two faces of the cavity results in a high interference fineness. Then, the anti-reflection coating process is applied to the sensor to improve the clarity of the interference signal with the cavity, with its wavelength working within the range of the C + L band. Next, the sensor placement is determined by the finite element software Nastran. Experimental results indicate that the sensor exhibits a good linear response (99.77%) to load changes and a high repeatability. Considering the strain transfer coefficient, the sensitivity for the tested structure load is as high as 35.6 pm/N. Due to the miniaturization, repeatability, and easy-to-batch production, the proposed sensor can be used as a reliable and practical force sensor

Ultra Short-Term Power Load Forecasting Based on Similar Day Clustering and Ensemble Empirical Mode Decomposition

With the increasing demand of the power industry for load forecasting, improving the accuracy of power load forecasting has become increasingly important. In this paper, we propose an ultra short-term power load forecasting method based on similar day clustering and EEMD (Ensemble Empirical Mode Decomposition). In detail, the K-means clustering algorithm was utilized to divide the historical data into different clusters. Through EEMD, the load data of each cluster were decomposed into several sub-sequences with different time scales. The LSTNet (Long- and Short-term Time-series Network) was adopted as the load forecasting model for these sub-sequences. The forecast results for different sub-sequences were combined as the expected result. The proposed method predicts the load in the next 4 h with an interval of 15 min. The experimental results show that the proposed method obtains higher prediction accuracy than other comparable forecasting models