bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scalar structures around the mixing interface of a thermal mixing layer in multiscale-generated decaying turbulent flows visualized using DNS database
Authors: Jomura Shotaro , Suzuki Hiroki , Mochizuki Shinsuke , Sakai Yasuhiko 
Published: July 2021

Abstract
This study shows the results for the visualization of a scalar mixing layer in decaying turbulence produced by a multiscale-generated turbulence grid. For this purpose, a thermal mixing layer in the air is used as the scalar mixing layer. A fractal generating grid proposed in the previous study is used for the generation of multiscale-generated turbulence. In addition, a parameter for determining the grid shape is varied. The scalar field is then visualized using a database given by direct numerical simulations. The instantaneous scalar field, the instantaneous scalar fluctuation field, the instantaneous scalar variance field, and the scalar dissipation field are visualized, and the visualization results are discussed using the wake interaction length scale.
Inadequacy of the Shannon entropy in quantifying wave-particle duality for three-path interferometers
Authors: Lyu Xin 
Published: July 2021

Abstract
Based on the principle that any introduce of entanglement should not improve the limit of simultaneously obtainable information of the particle aspect and the wave aspect, we show that the Shannon entropy is not suitable for quantifying wave-particle duality by giving a counter example in three-path interferometers.
Orthogonality derivation of polarization state based on Poincaré sphere
Authors: Wang Zhanling , Huang Jiankai , Pang Chen 
Published: July 2021

Abstract
To make full use of the polarization information of electromagnetic waves for the polarimetric sensor array, we derive the orthogonality expression of the polarization state based on the Poincaré sphere (PS) representation. The ellipticity angle and the orientation angle of the ellipse are used to describe the polarization ellipse and the point on the surface of the Poincaré sphere. The derivation shows that two points that characterize a pair of orthogonal polarization states are distributed in the opposite positions. Compared with the conventional linear and circular polarization state, the flexible elliptical polarization state would result in the maximum separation of co-polarization and cross-polarization components, thereby enhancing the accuracy of polarization information measurement. The simulation result displays the correctness of the theoretical derivation, which could provide a basis for the further polarization state configuration.
Power-Maxwell holographic superconductors probed by entanglement entropy
Authors: Yao Weiping , Jiang Jiali , Yang Jiacheng 
Published: July 2021

Abstract
We study the behaviors of entanglement entropy (EE) in the Power-Maxwell holographic superconductors. We observe that the EE is a useful tool to study the critical point of the phase transition. The phase transition is less likely with the Power-Maxwell field. In the condensed phase, the EE gets larger as the strength of the Power-Maxwell field and the width increases. Furthermore, the width modifies the EE more significantly than the Power-Maxwell factor.
Stress field solution to anisotropic plate with mode II crack based on pan-complex function
Authors: Jia Purong , Suo Yongyong , Jia Cheng 
Published: July 2021

Abstract
The crack-tip stress problem to the anisotropic materials was mainly discussed under the shear loading model. For the sake of solving the stress boundary problem, the pan-complex function method was achieved in the first place. The elastic theory of composite materials has been clearly reviewed in order to determine the material physical parameters. Equilibrium equations and deformable compatibility condition were introduced on the basis of plane elastic mechanics. The key to the settlement of the boundary question must lie in solving the partial derivative equation and the axial transformation of the pan-complex variables. The reasonable stress functions were chosen in order to meet the needs of shear loading states. The pan-complex function and the polar coordinate replace approach are utilized with the aim of solving the stress boundary problems for the anisotropic plate. The formulas of the stress components near the crack-tip region were finally determined by the real functions. The method in this article may be much important to the fracture analysis of composite materials.
Electrochemical sensor based on graphene-modified GCE for rapid quantification of benzo(a)pyrene in dark rubber materials
Authors: Zhong Naifei , Yuan Ronghui , He Huihui , Zhong Wenhan , Wang Ying 
Published: July 2021

Abstract
Electrochemical sensor was constructed by depositing graphene on glassy carbon electrode (GCE), and the electrochemical properties of benzo(a)pyrene (BaP) were characterized. An oxidation peak was observed at 1.13 V according to the cyclic voltammogram with no reduction peak appeared. The differential pulse voltammetry revealed that sorption time and acid concentration play a prominent role in the oxidation of BaP-acetonitrile-NaClO4. A good linear relationship between oxidation peak current and concentration within the range from 0.5 to 30 ng mL−1 was developed. The limit of detection was calculated as 0.08 ng mL−1. Further, this reliable method was applied for BaP determination of the dark rubber materials on graphene-modified GCE. The advantages of its sensitivity and portability were noteworthy for the sample pretreatment and rapid quantification of BaP compared with gas chromatography-mass spectrometry method.
Parametric sensitivity analysis of Aerodynamic stability for planar membrane structures
Authors: Du Lingling , Song Weiju 
Published: July 2021

Abstract
To explore the influence of design parameters on the aerodynamic stability of planar membrane structures, a mathematical model for calculating the critical wind speed of flat panel structures was established, and the closed expression of the critical wind speed was obtained through the criterion of instability. The influence of membrane size, membrane density, pretension and other parameters on the critical wind speed was studied by monofactor analysis. The results show that, with the help of the new concept of benefit loss coefficient, the sensitivity analysis of instability critical wind speed parameters can be easily carried out, and many qualitative and quantitative laws can be obtained.
An improved multi-objective gravitational search algorithm
Authors: Guo Yuhong , Luo Teng , Cao Hongqian 
Published: July 2021

Abstract
Multi-objective search algorithm is a common optimization tool to deal with complex multi-objective problems, such as Multiple Objectives Particle Swarm Optimization (MOPSO) and Non dominated Sorting Genetic Algorithm-II (NSGA-II). Gravitational Search Algorithm (GSA) is a new heuristic evolutionary algorithm, which is based on the Newtonian gravity and the laws of motion to search optimal solutions. Some of agents have bigger mass, so other smaller mass agents are affected easily to fall into local optimization. In order to improve the search ability of the algorithm, this paper proposes an Improved Multi-Objective Gravitational Search Algorithm (IMOGSA). The proposed method uses the fast non-dominated sorting strategy and crowding distance of NSGA-II, and uses Sine Cosine Algorithm (SCA). Using strategy of NSGA-II is to reduce the complexity of the algorithm, in addition, using SCA is to improve the convergence and distribution of IMOGSA by improving the weight of acceleration. Finally, the proposed method has been compared with other well-known heuristic search methods by using some benchmark functions.
Contradiction argument in the study of convexity for a special case of Hessian equation in the ball
Authors: Lin Xiaomin , Ye Yunhua 
Published: July 2021

Abstract
The convexity is intimately related to geometric properties of solutions to partial differential equations. In this paper, the contradiction argument is used to study some convexity properties for the solutions of a special type of Hessian equation in the unit ball. It reveals that some power of the solution is strictly convex in the ball.
Pricing perpetual American straddle option driven by bifractional Black-Scholes model
Authors: Xu Feng , Ye Min 
Published: July 2021

Abstract
This paper addresses the pricing of perpetual American straddle options under the bifractional Black-Scholes model. We use the comparison principle for the variational inequality to analyze the behaviour of exercise boundaries for the perpetual American straddle option with a constant dividend yield. The conclusion is derived that it has two exercise boundary points with a constant dividend yield and only one free boundary point with zero dividend yield, which is consistent with the financial context.
Risk spillovers between China and other BRICS countries during COVID-19 pandemic: A CoVaR-copula approach
Authors: Cheng Yangnan , Liu Jianxu , Sriboonchitta Songsak 
Published: July 2021

Abstract
This paper aims to assess risk spillover effect between China and other BRICS countries by CoVaR-copula method. We analyse the result of ΔCoVaR in two sub-periods–year 2019 and COVID-19 period. Data for stock prices of major stock market in each country are used. Our results show that risk spillover effect from China to other BRICS countries increased during the epidemic. Meanwhile, COVID-19 pandemic enhanced the co-movement between China and other four countries. Under the shock from other countries, stock market in China stayed strong. By contrast, stock markets in Brazil, India and South Africa are vulnerable. The results show the accuracy of CoVaR-copula approach for risk spillover effect measurement.
Application of one-factor copula with Durante generators to high-dimensional data: empirical study on stock market of China
Authors: Cheng Yangnan , Liu Jianxu , Sriboonchitta Songsak 
Published: July 2021

Abstract
This paper investigates the performance of one-Factor copula with Durante generators (FDG copula) in high-dimensional applications. We use data with 28, 102 and 227 dimensions respectively to compare the mean absolute error in three cases. The results show that estimation error deceases as dimension increases, which means the higher the dimension, the better this model performs. Empirically, we measure the dependence between industrial sectors in Chinese stock market by FDG copulas. It is found that Machinery and equipment sector has the largest dependence coefficients with other sectors. In addition, by comparing the results before and during the COVID-19 pandemic, we find that the epidemic strengthened the connection between the Computer and Media industry and other industries. FDG copulas, tractable and flexible, suits well for high-dimensional estimation. Potential of its application to other fields remains to be discovered.
Project duration-cost-quality prediction model based on Monte Carlo simulation
Authors: Chen Xingguang , Cheng Luqiang , Deng Guohua , Guan Shuqi , Hu Lewei 
Published: July 2021

Abstract
Based on the earned value management theory, the project duration and cost forecast data are obtained through Monte Carlo simulation, combined with the knowledge of mathematical statistics to in-depth analysis of the data, and then the project quality calculation is completed by establishing the quality correlation function. On the basis of existing scholars’ research, at the process level, the management focus is identified by calculating process influence and quality, and at the project level, the operation of the entire project is simulated and predicted by the calculation of the total construction period, cost, and quality.
A fuzzy behavioral portfolio decision model with trapezoidal fuzzy return and aspiration
Authors: Zhang Qiansheng , Yao Haixiang 
Published: July 2021

Abstract
This paper deals with the stock portfolio selection problem involved with trapezoidal fuzzy number returns and multiple mental accounts. A fuzzy behavioral portfolio decision model is proposed to maximize the possibilistic mean value of portfolio return and ensure the portfolio return of each mental account exceeding the given minimum fuzzy aspiration level with a given probability. Then, some programming models are designed to solve the optimal portfolio strategy. Finally, one numerical example is given to illustrate the effectiveness of the proposed fuzzy behavioral portfolio decision approach.
Application of cluster analysis in optimization problem of pricing of a mobile Internet App
Authors: Bai Sixuan , Liao Daiqin , Wang Mei , Ma Yang 
Published: July 2021

Abstract
This paper focus on the problem of task pricing and completion of the tasks of a mobile Internet APP. Based on the original data set, the original pricing model of the project’s tasks was established by using the multiple linear regression analysis. The influences of factors such as the task point’s pricing, number of other tasks, and total task price on tasks completion were analysed. Further, based on the factors which affecting task completion, a new task pricing model was developed by using cluster analysis to tailor the price of some task points and significantly improved the completion of task without increasing the total task price.
Energy intensity gap between enterprises and governments: A global perspective
Authors: Wang Heng , Liu Jianxu , Sriboonchitta Songsak 
Published: July 2021

Abstract
Information asymmetry on energy efficiency target between enterprises and governments is a major controversy about sustainability. Enterprises desire to pursue the maximum profits in the market while governments confront with incomplete information on energy intensity potential and policy implementation. To investigate the influence of information gap between them, this study uses two-tier stochastic frontier (TSF) model with scaling property on the panel data in 56 contracting countries in Kyoto Protocol from 1995 to 2014 on energy intensity from energy, economic and technological perspective. The results present that on average about 70% of the unexplained variations in energy intensity accounts for the influence of energy intensity gap on energy savings potential between enterprises and governments. And the actual energy intensity is upper biased by average 7.03% due to the information asymmetry although the net impacts differ slightly across developing and developed countries and over time. Enterprises have stronger influence on the energy intensity during sample period. We recommend developing countries’ governments to have a strong renewable energy governance framework to support urbanization for economic development is their backbone for long period.
The dynamic dependence of natural gas and renewable energy stock markets
Authors: Zhou Yefan , Liu Jianxu , Sirisrisakulchai Jirakom , Sriboonchitta Songsak 
Published: July 2021

Abstract
We measure the dynamics dependence structure between the European renewable energy stock (ERIX) market, natural gas, and other clean energy markets from 2008 to 2021 by adopting static and time-varying copula approaches. Empirical results show strong and positive dependence between ERIX and S&P global clean energy stock markets symmetric tail dependence, which indicates S&P clean energy assets provide limited hedging condition on the ERIX market and extreme upward and downward clean prices have a similar impact on the ERIX market. Furthermore, our evidence on the co-movement mechanisms between European renewable energy and clean energy markets is helpful for policymakers and investors. Governments need to adopt fiscal policy tools for clean energy firms when renewable energy prices rise (fall) together. Investors can assess and control potential risk contagion between European renewable energy stock markets and other clean energy markets via information about co-movement mechanisms.
Albedo-induced global warming impact of Conservation Reserve Program grasslands converted to annual and perennial bioenergy crops
Authors: Abraha Michael , Chen Jiquan , Hamilton Stephen K , Sciusco Pietro , Lei Cheyenne , Shirkey Gabriela , Yuan Jing , Robertson G Philip 
Published: July 2021

Abstract
Climate benefit assessments of bioenergy crops often focus on biogeochemical impacts, paying little if any attention to biogeophysical impacts. However, land conversions required for large-scale bioenergy crop production are substantial and may directly affect the climate by altering surface energy balance. In the US, such land conversions are likely to be met in part by converting Conservation Reserve Program (CRP) grassland to bioenergy crops. Here, we converted three 22 year old CRP smooth brome grass fields into no-till corn, switchgrass, or restored prairie bioenergy crops. We assessed the biogeophysical climate impact of the conversions using albedo changes relative to unconverted reference CRP grassland. The corn and perennial fields had higher annual albedo than the grassland they replaced—causing cooling of the local climate. The cooling of the corn field occurred solely during the non-growing season—especially when surfaces were snow-covered, whereas the cooling of the perennial fields was more prominent during the growing season. Compared to biogeochemical impacts with fossil fuel offsets for the same land conversions over eight years, the annual albedo-induced climate benefits add ∼35% and ∼78% to the annual biogeochemical benefits provided from the switchgrass and restored prairie fields, respectively, and offset ∼3.3% of the annual greenhouse gas (GHG) emissions from the corn field. We conclude that albedo-induced climate mitigation from conversion of CRP lands to perennial but not annual bioenergy crops can be substantial, and future climate impact assessments of bioenergy crops should include albedo changes in addition to GHG balances in order to better inform climate policies.
Growing farms and groundwater depletion in the Kansas High Plains
Authors: Ao Yufei Z , Hendricks Nathan P , Marston Landon T 
Published: July 2021

Abstract
The average farm size has more than doubled within the United States over the last three decades, transforming the agricultural industry and rural farming communities. It is unclear, however, how this ubiquitous trend has affected and is affected by the environment, particularly groundwater resources critical for food production. Here, we leverage a unique multi-decadal dataset of well-level groundwater withdrawals for crop irrigation over the Kansas High Plains Aquifer to determine the interactions between groundwater depletion and growing farms. Holding key technological, management, and environmental variables fixed, we show that doubling a farm’s irrigated cropland decreases groundwater extractions by 2%–5% depending on the initial farm size. However, a corresponding shift by larger farms to different irrigation technologies offsets this reduction in groundwater use, leading to a slight increase in overall groundwater use. We find groundwater depletion increases the likelihood farmland is sold to a larger farm, amplifying the cycle of groundwater depletion and the consolidation of farmland.
Trends and legacy of freshwater salinization: untangling over 50 years of stream chloride monitoring
Authors: Mazumder Bhaswati , Wellen Christopher , Kaltenecker Georgina , Sorichetti Ryan J , Oswald Claire J 
Published: July 2021

Abstract
Excessive use of road salts to maintain safe winter travel conditions leads to increasing chloride (Cl) concentrations in streams, damaging the structure and function of freshwater ecosystems. Long-term increasing stream Cl trends are generally attributed to increases in urban land cover, however recent research shows that even relatively rural streams can retain Cl and exceed water quality guidelines in summer after road salting has stopped. Untangling the relative influences of long-term changes in streamflow and urban growth on Cl trends is critical for making informed decisions about road salt management. The portion of Cl trends not explained by changes in streamflow or urban growth could be due to changes in road salt application rates and/or legacy Cl in groundwater that is slowly making its way to streams. This study assessed seasonal, long-term stream Cl trends across the Province of Ontario, Canada, where urbanization accelerated and road salt management plans started to develop since early 2000s. We compared stream Cl trends over salting and non-salting seasons with urban growth estimates from two independent time periods, 1965–1995 and 2002–2018. For a subset of sites with sufficient flow data in the periods analyzed, we parsed the seasonal trends into flow and management trend components. We found that most of the variance in the management trend component in the winter salting season could be explained by urbanization, while about half of it could be explained in the summer non-salting season. We further analyzed Cl estimates in low-flow conditions to explore the extent of subsurface contributions to Cl trends, and concluded with a summary of challenges and recommendations for future studies on road salt legacy in streams.
The nature of intraspecific and interspecific genome size variation in taxonomically complex eyebrights
Authors: Becher Hannes , Powell Robyn F , Brown Max R , Metherell Chris , Pellicer Jaume , Leitch Ilia J , Twyford Alex D 
Published: July 2021

AbstractBackground and aimsGenome size varies considerably across the diversity of plant life. Although genome size is, by definition, affected by genetic presence/absence variants, which are ubiquitous in population sequencing studies, genome size is often treated as an intrinsic property of a species. Here, we studied intra- and interspecific genome size variation in taxonomically complex British eyebrights (Euphrasia, Orobanchaceae). Our aim is to document genome size diversity and investigate underlying evolutionary processes shaping variation between individuals, populations and species.MethodsWe generated genome size data for 192 individuals of diploid and tetraploid Euphrasia and analysed genome size variation in relation to ploidy, taxonomy, population affiliation and geography. We further compared the genomic repeat content of 30 samples.Key resultsWe found considerable intraspecific genome size variation, and observed isolation-by-distance for genome size in outcrossing diploids. Tetraploid Euphrasia showed contrasting patterns, with genome size increasing with latitude in outcrossing Euphrasia arctica, but with little genome size variation in the highly selfing Euphrasia micrantha. Interspecific differences in genome size and the genomic proportions of repeat sequences were small.ConclusionsWe show the utility of treating genome size as the outcome of polygenic variation. Like other types of genetic variation, such as single nucleotide polymorphisms, genome size variation may be affected by ongoing hybridization and the extent of population subdivision. In addition to selection on associated traits, genome size is predicted to be affected indirectly by selection due to pleiotropy of the underlying presence/absence variants.