Energy exchange between (3+1)D colliding spatiotemporal optical solitons in dispersive media with cubic-quintic nonlinearity

We investigate the energy exchange between （3＋1）D colliding spatiotemporal solitons （STSs） in dispersive media with cubic-quintic （CQ） nonlinearity by numerical simulations. Energy exchange between two （3＋1）D head on colliding STSs caused by their phase difference is observed, just as occurring in other optical media. Moreover, energy exchange between two head-on colliding STSs with different speeds is firstly shown in the CQ and saturable media. This phenomenon, we believe, may arouse some interest in the future studies of soliton collision in optical media.

Optimal Expansion Planning Model for Integrated Energy System Considering Integrated Demand Response and Bidirectional Energy Exchange

The challenges of energy shortage and environmen-tal protection motivate people to take various measures to use energy wisely,and integrated energy systems are such a measure to tackle this challenge.In this paper,an optimal expansion planning model for an integrated energy system consisting of power grid,gas network and multiple energy hubs is proposed,where the planning objective is to minimize operational fuel cost and capital investment cost covering carbon capture equipment and energy hubs among others.To demonstrate the advantage of the proposed planning model,six case studies are investigated,and 13.47%annual cost savings can be achieved compared with the baseline planning scenario,which does not consider bidirectional energy exchange and integrated demand response program.Index Terms-Bidirectional energy exchange,energy hubs,integrated energy system,integrated demand response.

Energy Exchange Control in Multiple Microgrids with Transactive Energy Management

In recent years,the advent of microgrids with numerous renewable energy sources has created some fundamental challenges in the control,coordination,and management of energy trading between microgrids and the power grid.To respond to these challenges,some techniques such as the transactive energy(TE)technology are proposed to control energy sharing.Therefore,this paper uses TE technology for energy exchange control among the microgrids,and applies three operation cases for analyzing the energy trading control of four and ten microgrids with the aim of minimizing the energy cost of each microgrid,respectively.In this regard,Monte Carlo simulation and fast forward selection(FFS)methods are respectively exerted for scenario generation and reduction in uncertainty modeling process.The first case is assumed that all microgrids can only receive energy from the network and do not have any connection with each other.In order to maximize the energy cost saving of each microgrid,the second case is proposed to provide a positive percentage of cost saving for microgrids.All microgrids can also trade energy with each other to get the most benefit by reducing the dependency on the main grid.The third case is similar to the second case,but its target is to indicate the scalability of the models based on the proposed TE technology by considering ten commercial microgrids.Finally,the simulation results indicate that microgrids can achieve the positive amount of cost saving in the second and third cases.In addition,the total energy cost of microgrids has been reduced in comparison with the first case.

Parametric instability in the pure-quartic nonlinear Schrödinger equation

We study the nonlinear stage of modulation instability(MI)in the non-intergrable pure-quartic nonlinear Schrödinger equation where the fourth-order dispersion is modulated periodically.Using the three-mode truncation,we reveal the complex recurrence of parametric resonance(PR)breathers,where each recurrence is associated with two oscillation periods(PR period and internal oscillation period).The nonlinear stage of parametric instability admits the maximum energy exchange between the spectrum sidebands and central mode occurring outside the MI gain band.

Autumn Daily Characteristics of Land Surface Heat and Water Exchange over the Loess Plateau Mesa in China

The Loess Plateau, located in northern China, has a significant impact on the climate and ecosystem evolvement over the East Asian continent. In this paper, the preliminary autumn daily characteristics of land surface energy and water exchange over the Chinese Loess Plateau mesa region are evaluated by using data collected during the Loess Plateau land-atmosphere interaction pilot experiment （LOPEX04）, which was conducted from 25 August to 12 September 2004 near Pingliang city, Gansu Province of China. The experiment was carried out in a region with a typical landscape of the Chinese Loess Plateau, known as ＂loess mesa＂. The experiment＇s field land utilizations were cornfield and fallow farmland, with the fallow field later used for rotating winter wheat. The autumn daily characteristics of heat and water exchange evidently differed between the mesa cornfield and fallow, and the imbalance term of the surface energy was large. This is discussed in terms of sampling errors in the flux observations-footprint; energy storage terms of soil and vegetation layers; contribution from air advections; and low and high frequency loss of turbulent fluxes and instruments bias. Comparison of energy components between the mesa cornfield and the lowland cornfield did not reveal any obvious difference. Inadequacies of the field observation equipment and experimental design emerged during the study, and some new research topics have emerged from this pilot experiment for future investigation.

Energy and first law of thermodynamics for Born-Infeld-anti-de-Sitter black hole

We calculate the local energy and the energy density of the Reisner-Norstrom-anti-de-Sitter black hole, study the first law of thermodynamics and show the Smarr formula for the Born-Infeld-anti-de-Sitter black hole. Applying the first law of thermodynamics to the black hole region, we analyse the three energy exchange processes between the black hole region and the outer and the inner regions.

Molecular Exchanging Energy of Anionic/Cationic Surfactants System on the Surface of Solution

In order to study synergism of the mixed surfactants system with molecular exchanging energy (E), the Lennard-Jones formula has been firstly introduced to evaluate the E of the mixed system, CH3(CH2)nOSO 3 /CH3(CH2)nN+(CH3)3 directly from their molecular structure. The comparison of the calculated and the observed results showed that this method is practical.

The Pionic Effect on the Binding Energy of Relativistic Particle-Hole Excitation in Nuclear Matter

The renormalization of pion-exchange nucleon self-energy in nuclear matter is doneby dispersion relation.The exchange and correlation energies(in the ring approximation)ofpion,σ and ω mesons are derived and used to calculate the binding energy of nuctear matter atzero temperature.We find that the pionic contribution to the binding energy fails to lift the highdensity end of the binding energy curve,that is,the binding energy can not saturate without adensity dependent correction to the σNN and ωNN coupling constants.But the binding energycan saturate in the relativistic Hartree approximation plus the exchange and correlation energiesof л meson.

Dataset of Comparative Observations for Land Surface Processes over the Semi-Arid Alpine Grassland against Alpine Lakes in the Source Region of the Yellow River

Thousands of lakes on the Tibetan Plateau(TP) play a critical role in the regional water cycle, weather, and climate. In recent years, the areas of TP lakes underwent drastic changes and have become a research hotspot. However, the characteristics of the lake-atmosphere interaction over the high-altitude lakes are still unclear, which inhibits model development and the accurate simulation of lake climate effects. The source region of the Yellow River(SRYR) has the largest outflow lake and freshwater lake on the TP and is one of the most densely distributed lakes on the TP. Since 2011,three observation sites have been set up in the Ngoring Lake basin in the SRYR to monitor the lake-atmosphere interaction and the differences among water-heat exchanges over the land and lake surfaces. This study presents an eight-year(2012–19), half-hourly, observation-based dataset related to lake–atmosphere interactions composed of three sites. The three sites represent the lake surface, the lakeside, and the land. The observations contain the basic meteorological elements,surface radiation, eddy covariance system, soil temperature, and moisture(for land). Information related to the sites and instruments, the continuity and completeness of data, and the differences among the observational results at different sites are described in this study. These data have been used in the previous study to reveal a few energy and water exchange characteristics of TP lakes and to validate and improve the lake and land surface model. The dataset is available at National Cryosphere Desert Data Center and Science Data Bank.

Motion and acceleration of electrons in high-intensity laser standing waves

The motion and the energy of electrons driven by the ponderomotive force in linearly polarized high-intensity laser standing wave fields are considered. The results show that there exists a threshold laser intensity, above which the motion of electrons incident parallel to the electric field of the laser standing waves undergoes a transition from regulation to chaos. We propose that the huge energy exchange between the electrons and the strong laser standing waves is triggered by inelastic scattering, which is related to the chaos patterns. It is shown that an electron＇s energy gain of tens of MeV can be realized for a laser intensity of 10^20 W/cm^2.

Operation Strategy of EV Battery Charging and Swapping Station

An operation strategy of the electric vehicle （EV） battery charging and swapping station is proposed in the paper. The strategy is established based on comprehensively consideration of the EV charging behaviors and the possible mutual actions between battery charging and swapping. Three energy management strategies can be used in the station： charging period shifting, energy exchange between EVs, and energy supporting from surplus swapping batteries. Then an optimization model which minimizes the total energy management costs of the station is built. The Monte Carlo simulation is applied to analyze the characteristics of the EV battery charging load, and a heuristic algorithm is used to solve the strategy providing the relevant information of EVs and the battery charging and swapping station. The operation strategy can efficiently reduce battery charging during the high electricity price periods and make more reasonable use of the resources. Simulations prove the feasibility and rationality of the strategy.

Exciton dynamics in luminescent carbon nanodots： Electron-hole exchange interaction

The electron-hole exchange interaction significantly influences the optical properties of excitons and radiative decay. However, exciton dynamics in luminescent carbon dots （Cdots） is still not clear. In this study, we have developed a simple and efficient one-step strategy to synthesize luminescent Cdots using the pyrolysis of oleylamine. The sp^2 clusters of a few aromatic rings are responsible for the observed blue photoluminescence. The size of these clusters can be tuned by controlling the reaction time, and the energy gap between the π-π＊ states of the sp^2 domains decreases as the sp^2 cluster size increases. More importantly, the strong electron-hole exchange interaction results in the splitting of the exciton states of the sp^2 clusters into the singlet-bright and triplet-dark states with an energy difference ΔE, which decreases with increasing sp^2 cluster size owing to the reduction of the confinement energy and the suppression of the electron-hole exchange interaction.

Benzimidazolium Functionalized Polysulfone-based Anion Exchange Membranes with Improved Alkaline Stability

The stability of anion exchange membranes（AEMs） is an important feature of alkaline exchange membrane fuel cells（AEMFCs）, which has been extensively studied. However it remains a real challenge due to the harsh working condition. Herein, we developed a novel type of polysulfone-based AEMs with three modified 1,2-dimethylbenzimidazoliums containing different substitutes at C4-and C7-position. The results showed that the introduction of the substitutes could obviously improve the dimensional and alkaline stabilities of the corresponding membranes. The swelling ratios of resultant AEMs were all lower than 10% after water immersion. The membrane with 4,7-dimethoxy-1,2-dimethylbenzimidazolium group exhibited the highest alkaline stability. Only 9.2% loss of hydroxide conductivity was observed after treating the membrane in 1 mol·L^（-1） KOH solution at 80 °C for 336 h. Furthermore, the density functional theory（DFT） study on the three functional group models showed that the substitutes at C4-and C7-position affected the lowest unoccupied molecular orbital（LUMO） energies of the different 1,2-dimethylbenzimidazolium groups.

Experimental and Numerical Research on Strengthening the Performance of Wave Rotor Equipment with Curved Passages

The wave rotor technology is an energy exchanging approach that achieves efficient energy transfer between gases without using mechanical components.The wave rotor technology has been successfully utilized in gas turbine cycle systems,gas expansion refrigeration and a variety of other industrial domains,yielding numerous researches and application outcomes.The structure of wave rotor passages inside which the energy exchange between gases is realized has an important impact on the equipment performance.In this study,based on gas wave ejection technology,the first application trials of an expansion wave rotor with curved passages were conducted.Additionally,the performance enhancing effect and mechanism of curved passages on the energy exchanging process were studied precisely by the combination of experimental and three-dimensional numerical simulation methods.The experimental results demonstrate that the curved passage rotor(CIR rotor)employed in this research has a maximum isentropic efficiency of 61.6%,and the CIR rotor achieves higher efficiency than the straight passage rotor(STR rotor)on all working conditions in this study.Compared with the STR rotor,the maximum efficiency improving ratio of CIR rotor can exceed 14.2%at each experimental expansion ratio,and the maximum relative increments of ejection rate are more than 5%.In addition,the CIR rotor can also effectively increase the proportion of static pressure in total pressure of the medium-pressure gas,and reduce the device power consumption.The three-dimensional numerical investigations revealed the principle of gas ejection in the wave rotors and explained why the CIR rotor performed better.According to the numerical findings,the curved passages of the CIR rotor may effectively minimize various energy losses created in the processes of high-pressure gas incidence,exhausting flow in nozzle,and high-speed gas flow in the passages.

Applied machine learning in greenhouse simulation;new application and analysis

Prediction the inside environment variables in greenhouses is very important because they play a vital role in greenhouse cultivation and energy lost especially in cold and hot regions.The greenhouse environment is an uncertain nonlinear system which classical modeling methods have some problems to solve it.So the main goal of this study is to select the best method between Artificial Neural Network(ANN)and Support Vector Machine(SVM)to estimate three different variables include inside air,soil and plant temperatures(Ta,Ts,Tp)and also energy exchange in a polyethylene greenhouse in Shahreza city,Isfahan province,Iran.The environmental factors which influencing all the inside temperatures such as outside air temperature,wind speed and outside solar radiation were collected as data samples.In this research,13 different training algorithms were used for ANN models(MLPRBF).Based on K-fold cross validation and Randomized Complete Block(RCB)methodology,the best model was selected.The results showed that the type of training algorithm and kernel function are very important factors in ANN(RBF and MLP)and SVM models performance,respectively.Comparing RBF,MLP and SVM models showed that the performance of RBF to predict Ta,Tp and Ts variables is better according to small values of RMSE and MAPE and large value of R2 indices.The range of RMSE and MAPE factors for RBF model to predict Ta,Tp and Ts were between 0.07 and 0.12
C and 0.28-0.50%,respectively.Generalizability and stability of the RBF model with 5-fold cross validation analysis showed that this method can use with small size of data groups.The performance of best model(RBF)to estimate the energy lost and exchange in the greenhouse with heat transfer models showed that this method can estimate the real data in greenhouse and then predict the energy lost and exchange with high accuracy.