Modern metropolises are increasingly affected by air quality problems. Transportation is one of the largest sources of several pollutants emissions, such as nitrogen oxides (NOx) and carbon monoxide (CO). Today in the...Modern metropolises are increasingly affected by air quality problems. Transportation is one of the largest sources of several pollutants emissions, such as nitrogen oxides (NOx) and carbon monoxide (CO). Today in the EU, vehicles' emissions are strictly limited by Euro 6 norm-Euro VI for heavy-duty vehicles-which is periodically upgraded. To match such limits, manufacturers are forced in developing new technologies to perform new sustainable vehicles design strategies, such as EVs and HEVs. Present work's aim is to provide the design of series-hybrid urban transportation bus, equipped with a novel thermal power unit, namely a small gas turbine, to exploit its cleaner combustion process in comparison with an ICE. The control logic is described, while the main drivetrain components are chosen, and suitable models from suppliers are selected as well. Then, some simulations of the resulting vehicle are performed on opportune drive cycles, using Advisor, a free software based on Matlab-Simulink environment, published by US' National Renewable Energy Laboratory (NREL). Two different final configurations are environmentally and economically analysed, with the thermal power unit being respectively fuelled by compressed natural gas (CNG) and liquefied petroleum gas (LPG). Both satisfy the Euro VI norms, showing a substantial emission reduction (-89% and -43% in CO and THC releases respectively) in comparison to pollutants' threshold values.展开更多
In this paper we will see the model of Universe according to Dynamic Universe Model of Cosmology by visualizing various processes that are happening in the Universe as per experimental evidences. For simplifying the m...In this paper we will see the model of Universe according to Dynamic Universe Model of Cosmology by visualizing various processes that are happening in the Universe as per experimental evidences. For simplifying the matter here, we will see in part 1: about the Galaxy life cycle, where the birth and death of Galaxies discussed. Probably Universe gives guidance for the movement of Galaxies. We call this Part 1: Thinking and Reproducing Universe or Mindless Universe? (Galaxy life cycle). We see every day Sun, Stars, Galaxies etc., dissipating enormous energy in the form of radiation by the way of fusion of Hydrogen to helium. So after sometime all the Hydrogen is spent and Universe will die, is it not? … Dynamic Universe Model says that the energy in the form of electromagnetic radiation passing grazingly near any gravitating mass changes in frequency and finally will convert into neutrinos (mass). Hence Dynamic Universe Model proposes another process where energy will be converted back into matter and the cycle energy to mass to energy continues, sustaining the Universe to maintain this present status for ever in this form something like a Steady state model without any expansion. This we will see in Part 2: Energy - Mass - Energy Cycle. After converting energy into mass “how various elements are formed and where they are formed?” will be next logical question. Dynamic Universe Model says that these various particles change into higher massive particles or may get bombarded into stars or planets and various elements are formed. Here we bifurcate the formation of elements into 6 processes. They are for Elementary particles and elements generated in frequency changing process, By Cosmic rays, By Small stars, By Large Stars, By Super Novae and Manmade elements By Neutron Stars. This we will discuss in Part 3: Nucleosynthesis.展开更多
In this paper,the forecasting equations of a 2nd-order space-time differential remainder are deduced from the Navier-Stokes primitive equations and Eulerian operator by Taylor-series expansion.Here we introduce a cubi...In this paper,the forecasting equations of a 2nd-order space-time differential remainder are deduced from the Navier-Stokes primitive equations and Eulerian operator by Taylor-series expansion.Here we introduce a cubic spline numerical model(Spline Model for short),which is with a quasi-Lagrangian time-split integration scheme of fitting cubic spline/bicubic surface to all physical variable fields in the atmospheric equations on spherical discrete latitude-longitude mesh.A new algorithm of"fitting cubic spline—time step integration—fitting cubic spline—……"is developed to determine their first-and2nd-order derivatives and their upstream points for time discrete integral to the governing equations in Spline Model.And the cubic spline function and its mathematical polarities are also discussed to understand the Spline Model’s mathematical foundation of numerical analysis.It is pointed out that the Spline Model has mathematical laws of"convergence"of the cubic spline functions contracting to the original functions as well as its 1st-order and 2nd-order derivatives.The"optimality"of the 2nd-order derivative of the cubic spline functions is optimal approximation to that of the original functions.In addition,a Hermite bicubic patch is equivalent to operate on a grid for a 2nd-order derivative variable field.Besides,the slopes and curvatures of a central difference are identified respectively,with a smoothing coefficient of 1/3,three-point smoothing of that of a cubic spline.Then the slopes and curvatures of a central difference are calculated from the smoothing coefficient 1/3 and three-point smoothing of that of a cubic spline,respectively.Furthermore,a global simulation case of adiabatic,non-frictional and"incompressible"model atmosphere is shown with the quasi-Lagrangian time integration by using a global Spline Model,whose initial condition comes from the NCEP reanalysis data,along with quasi-uniform latitude-longitude grids and the so-called"shallow atmosphere"Navier-Stokes primitive equations in the spherical coordinates.The Spline Model,which adopted the Navier-Stokes primitive equations and quasi-Lagrangian time-split integration scheme,provides an initial ideal case of global atmospheric circulation.In addition,considering the essentially non-linear atmospheric motions,the Spline Model could judge reasonably well simple points of any smoothed variable field according to its fitting spline curvatures that must conform to its physical interpretation.展开更多
We developed a detailed simulation model of the Arctic marine transport system(MTS) for oil platform Prirazlomnaya. The model has a multidisciplinary nature and involves: sub-models of various transport and technologi...We developed a detailed simulation model of the Arctic marine transport system(MTS) for oil platform Prirazlomnaya. The model has a multidisciplinary nature and involves: sub-models of various transport and technological processes; stochastic weather generator to obtain time series of 15 environmental parameters; and contextual planning algorithm to build voyage plan considering several types of ships and cargoes. We used a significant amount of real operational data to identify model parameters and to prove its statistical reliability. Our main scientific task is to investigate the interaction of various processes of a different nature, while the practical aim is to find a set of measures to increase the efficiency of MTS. The results of the study reveal many examples of the mutual interaction of various processes that need to be considered at the design stage to avoid technical mistakes.The study formed a basis for making managerial decisions at the top level of Gazprom Neft Shelf Company.展开更多
To address the challenges in studying the pore formation and evolution processes,and unclear preservation mechanisms of deep to ultra-deep carbonate rocks,a high-temperature and high-pressure visualization simulation ...To address the challenges in studying the pore formation and evolution processes,and unclear preservation mechanisms of deep to ultra-deep carbonate rocks,a high-temperature and high-pressure visualization simulation experimental device was developed for ultra-deep carbonate reservoirs.Carbonate rock samples from the Sichuan Basin and Tarim Basin were used to simulate the dissolution-precipitation process of deep to ultra-deep carbonate reservoirs in an analogous geological setting.This unit comprises four core modules:an ultra-high temperature,high pressure triaxial stress core holder module(temperature higher than 300°C,pressure higher than 150 MPa),a multi-stage continuous flow module with temperature-pressure regulation,an ultra-high temperature-pressure sapphire window cell and an in-situ high-temperature-pressure fluid property measurement module and real-time ultra-high temperature-pressure permeability detection module.The new experimental device was used for simulation experiment,the geological insights were obtained in three aspects.First,the pore-throat structure of carbonate is controlled by lithology and initial pore-throat structure,and fluid type,concentration and dissolution duration determine the degree of dissolution.The dissolution process exhibits two evolution patterns.The dissolution scale is positively correlated to the temperature and pressure,and the pore-forming peak period aligns well with the hydrocarbon generation peak period.Second,the dissolution potential of dolomite in an open flow system is greater than that of limestone,and secondary dissolved pores formed continuously are controlled by the type and concentration of acidic fluids and the initial physical properties.These pores predominantly distribute along pre-existing pore/fracture zones.Third,in a nearly closed diagenetic system,after the chemical reaction between acidic fluids and carbonate rock reaches saturation and dynamic equilibrium,the pore structure no longer changes,keeping pre-existing pores well-preserved.These findings have important guiding significance for the evaluation of pore-throat structure and development potential of deep to ultra-deep carbonate reservoirs,and the prediction of main controlling factors and distribution of high-quality carbonate reservoirs.展开更多
This paper deals with the increasing safety of working in aggressive potential locations, having SCADA system and WSN sensors, using a “probabilistic strategy” in comparison with a “deterministic” one, modeling/si...This paper deals with the increasing safety of working in aggressive potential locations, having SCADA system and WSN sensors, using a “probabilistic strategy” in comparison with a “deterministic” one, modeling/simulation and application in underground coal mining. In general, three conditions can be considered: 1) an unfriendly environment that facilitates the risk of accidents, 2) aggressive equipments that can compete to cause accidents and 3) the work security breaches that can cause accidents. These conditions define the triangle of accidents and are customized for an underground coal mining where the methane gas is released with the exploitation of the massive coal. In this case, the first two conditions create an explosive potential atmosphere. To allow people to work in a safe location it needs: first, a continuing monitoring through SCADA system of the explosive potential atmosphere and second, the use of antiexplosive equipment. This method, named “deterministic strategy”, increases the safety of working, but the explosions have not been completely eliminated. In order to increase the safety of working, the paper continues with the presentation of a new method based on hazard laws, named “probabilistic strategy”. This strategy was validated through modeling/simulation using CupCarbon software platform, and application of WSN networks implemented on Arduino equipments. At the end of the paper the interesting conclusions are emphases which are applicable to both strategies.展开更多
提出了一种基于最小二乘支持向量机的织物剪切性能预测模型,并且采用遗传算法进行最小二乘支持向量机的参数优化,将获得的样本进行归一化处理后,将其输入预测模型以得到预测结果.仿真结果表明,基于最小二乘支持向量机的预测模型比BP神...提出了一种基于最小二乘支持向量机的织物剪切性能预测模型,并且采用遗传算法进行最小二乘支持向量机的参数优化,将获得的样本进行归一化处理后,将其输入预测模型以得到预测结果.仿真结果表明,基于最小二乘支持向量机的预测模型比BP神经网络和线性回归方法具有更高的精度和范化能力.
Abstract：
A new method is proposed to predict the fabric shearing property with least square support vector machines ( LS-SVM ). The genetic algorithm is investigated to select the parameters of LS-SVM models as a means of improving the LS- SVM prediction. After normalizing the sampling data, the sampling data are inputted into the model to gain the prediction result. The simulation results show the prediction model gives better forecasting accuracy and generalization ability than BP neural network and linear regression method.展开更多
HB-MAP （HB-mutual authentication protocol） is a mutual ultra-light-weight authentication protocol we have pro- posed before. In this paper, we present an HB-MAP simulation model. This model is based on the OPNET mod...HB-MAP （HB-mutual authentication protocol） is a mutual ultra-light-weight authentication protocol we have pro- posed before. In this paper, we present an HB-MAP simulation model. This model is based on the OPNET modeler and includes three parts, namely, the network model, the node model, and the process model. The simulation results are obtained mainly in the aspects of running time, queuing delay, throughput, and channel utilization. To show the performance of HB-MAP, simulation of two other protocols HB and LCAP （load-based concurrent access protocol） is also executed, and comparative analysis is carried out on the results. At the end of the paper, we show a simple process of the attacks and identify that the HB-MAP can defend against some attacks.展开更多
The kinetic parameters of hydrocarbon generation are determined through experimental simulation and mathematical calculation using four typical samples selected from the Cretaceous Nenjiang Formation in the northwest ...The kinetic parameters of hydrocarbon generation are determined through experimental simulation and mathematical calculation using four typical samples selected from the Cretaceous Nenjiang Formation in the northwest of Songliao Basin,Chang 7 Member of Triassic Yanchang Formation in the southwest of Ordos Basin,Paleogene in the southwest of Qaidam Basin,and Lucaogou Formation of Jimusar Sag in the east of Junggar Basin.The results show that activation energy of hydrocarbon generation of organic matter is closely related to maturity and mainly ranges between 197 kJ/mol and 227 kJ/mol.On this basis,the temperature required for organic matter in shale to convert into oil was calculated.The ideal heating temperature is between 270℃and 300℃,and the conversation rate can reach 90%after 50-300 days of heating at constant temperature.When the temperature rises at a constant rate,the temperature corresponding to the major hydrocarbon generation period ranges from 225 to 350℃at the temperature rise rate of 1-150℃/month.In order to obtain higher economic benefits,it is suggested to adopt higher temperature rise rate(60-150℃/month).The more reliable kinetic parameters obtained can provide a basis for designing more reasonable scheme of in-situ heating conversion.展开更多
Fiber-reinforced polymer(FRP)composites are renowned for their high mechanical strength,durability,and lightweight properties,making them integral to civil engineering,aerospace,and automotive manufacturing.Traditiona...Fiber-reinforced polymer(FRP)composites are renowned for their high mechanical strength,durability,and lightweight properties,making them integral to civil engineering,aerospace,and automotive manufacturing.Traditionally,the simulation and optimization of FRP materials have relied on finite element(FE)methods,which,while effective,often fall short in capturing the intricate behaviors of these composites under diverse conditions.Concrete examples in this regard involve modeling interfacial cracks,delaminations,or environmental effects that involve nonlinear phenomena.These degradation mechanisms exceed the capacity of classical FE models,as they are not detailed to the required level of detail.This aspect increases the time and computational resources required,leading to a need for optimization regarding fiber reinforcement configurations or multiple scenario load analysis.Thus,FE methods are inefficient compared to AI-based approaches that generalize material behavior based on extensive datasets.The advent of artificial intelligence(AI)has introduced advanced tools capable of enhancing the analysis and design of FRP materials.This review examines the current landscape of AI applications in FRP composite simulations,highlighting existing research gaps.Through a comprehensive bibliometric analysis,the study underscores the limited number of investigations focused on leveraging AI for FRP optimization.Furthermore,it synthesizes findings related to AI-driven simulation techniques,the mechanical properties of FRP composites,and strategies for predicting and improving their durability.This review comprehensively explores the potential of AI to overcome these limitations by synthesizing over 170 scientific works published between 2015 and 2025.Key findings highlight that supervised learning methods—especially neural networks,support vector machines,and gradient boosting models—achieve prediction accuracies above 90%for mechanical properties and defect classification.However,bibliometric analysis reveals that there are limited studies that address AI-driven optimization or standardized datasets for FRP applications.This review identifies eight core classification domains and eight regression domains where AI excels,including defect detection,bond strength prediction,and fiber orientation optimization.展开更多
0 INTRODUCTION In recent years,modern railways have been actively under construction in the complex mountainous area of Southwest China.However,rockfall poses a significant threat to both construction and operation ph...0 INTRODUCTION In recent years,modern railways have been actively under construction in the complex mountainous area of Southwest China.However,rockfall poses a significant threat to both construction and operation phases of railway projects(Yan et al.,2023;Chen et al.,2022;Fanos and Pradhan,2018).展开更多
Simulating U(1) quantum gauge theories with spatial dimensions greater than one is of great physical significance. Here we propose a simple realization of U(1) gauge theory with Rydberg and Rydberg-dressed atom arrays...Simulating U(1) quantum gauge theories with spatial dimensions greater than one is of great physical significance. Here we propose a simple realization of U(1) gauge theory with Rydberg and Rydberg-dressed atom arrays. Within the experimentally accessible range, we find that the various aspects of the U(1) gauge theory can be well simulated, such as the emergence of topological sectors, incommensurability, and the Rokhsar–Kivelson point that hosts deconfined charge excitations and degenerate topological sectors. Our proposal is promising to implement experimentally and exhibits pronounced quantum dynamics.展开更多
We calculate the electrical and thermal conductivity of hydrogen for a wide range of densities and temperatures by using molecular dynamics simulations informed by density functional theory.On the basis of the corresp...We calculate the electrical and thermal conductivity of hydrogen for a wide range of densities and temperatures by using molecular dynamics simulations informed by density functional theory.On the basis of the corresponding extended ab initio data set,we construct interpolation formulas covering the range from low-density,high-temperature to high-density,low-temperature plasmas.Our conductivity model repro-duces the well-known limits of the Spitzer and Ziman theory.We compare with available experimental data andfind very good agreement.The new conductivity model can be applied,for example,in dynamo simulations for magneticfield generation in gas giant planets,brown dwarfs,and stellar envelopes.展开更多
Numerical simulation of diode-pumped Q-switched Nd:YAG laser leading to the generation of eye-safe signal in singly resonant Intracavity Optical Parametric Oscillator (IOPO) is presented. Starting from rate equations,...Numerical simulation of diode-pumped Q-switched Nd:YAG laser leading to the generation of eye-safe signal in singly resonant Intracavity Optical Parametric Oscillator (IOPO) is presented. Starting from rate equations, the time dependent laser equations have been solved numerically, whereas the space-dependent OPO equations analytically. Our results show that 1.4 J diode laser (810 nm) pulse with 200 msec width, delivers 30 mJ Nd:YAG laser (1064 nm) pulse with 5 n-second width. This Nd:YAG laser further generates 9 mJ eye safe signal (1570 nm) pulse with 2.5 n-second width.展开更多
The Underwater Communication Link(UCL)is a crucial component of Underwater Wireless Optical Communication(UWOC)systems,requiring optimised design to mitigate the high power attenuation inherent in seawater.To ensure t...The Underwater Communication Link(UCL)is a crucial component of Underwater Wireless Optical Communication(UWOC)systems,requiring optimised design to mitigate the high power attenuation inherent in seawater.To ensure the reliability of an optimal UCL design,it is essential to account for the three primary scattering regimes:forward scattering(FSC),backward scattering(BSC),and isotropic scattering(ISC)in seawater channels.This study introduces a new photon-tracking model based on a discrete equation,facilitating Monte Carlo Simulation(MCS)to evaluate how different scattering regimes influence received photon distribution.Three distinct Scattering Regime Contribution Weight(SRCW)probability sets were employed,each representing different UCL operational configurations dominated by specific scattering regimes.The proposed modeling approach enables a comprehensive assessment of the temporal characteristics of received optical pulses,channel loss,and time spread-ultimately defining the optimal UCL design parameters.The key findings of this study include:(1)Enhancing the FSC regime dominance leads to a quasi-light waveguide effect over link spans and small Fields of View(FOV)<25°,significantly improving channel performance in Harbor seawater compared to Coastal seawater.(2)A well-designed UCL with a small FOV(<25°)can minimise channel loss and time spread,ensuring high capacity and efficient performance in both Coastal and Harbor seawaters.(3)When BSC and ISC contributions exceed FSC dominance,the received optical pulse undergoes significant temporal broadening,particularly for larger FOV angles(>25°)and extended link spans.(4)The developed novel MCS-based discrete equation provides a simple yet robust model for simulating photon propagation in both homogeneous and inhomogeneous underwater channels.These insights contribute to developing more efficient and reliable UCL designs with military standards by enhancing UWOC system performance over a longer linkspan for a given limited optical power across various underwater environments.展开更多
Large quantities of blast furnace(BF) slag and CO_2 are discharged annually from iron and steel industries, along with a large amount of waste heat.The mineral carbonation of BF slag can not only reduce emissions of s...Large quantities of blast furnace(BF) slag and CO_2 are discharged annually from iron and steel industries, along with a large amount of waste heat.The mineral carbonation of BF slag can not only reduce emissions of solid waste but also realize the in-situ fixation of CO_2 with low energy consumption if integrated with the waste heat utilization.In this study, based on our previous works, Aspen Plus was employed to simulate and optimize the carbonation process and integrate the process energy.The effects of gehlenite extraction, MgSO_4 carbonation,and aluminum ammonium sulfate crystallization were studied systematically.The simulation results demonstrate that 2.57 kg of BF slag can sequester 1 kg of CO_2, requiring 5.34 MJ of energy(3.3 MJ heat and 2.04 MJ electricity), and this energy includes the capture of CO_2 from industrial flue gases.Approximately 60 kg net CO_2 emission reduction could be achieved for the disposal of one ton of BF slag.In addition, the by-product,aluminum ammonium sulfate, is a high value-added product.Preliminary economic analysis indicates that the profit for the whole process is 1127 CNY per ton of BF slag processed.展开更多
In this study,a new linear friction welding(LFW)process,embedded LFW process,was put forward,which was mainly applied to combination manufacturing of long or overlong loadcarrying titanium alloy structural components ...In this study,a new linear friction welding(LFW)process,embedded LFW process,was put forward,which was mainly applied to combination manufacturing of long or overlong loadcarrying titanium alloy structural components in aircraft.The interfacial plastic flow behavior and bonding mechanism of this process were investigated by a developed coupling EulerianLagrangian numerical model using software ABAQUS and a novel thermo-physical simulation method with designed embedded hot compression specimen.In addition,the formation mechanism and control method of welding defects caused by uneven plastic flow were discussed.The results reveal that the plastic flow along oscillating direction of this process is even and sufficient.In the direction perpendicular to oscillation,thermo-plastic metals mainly flow downward along welding interface under coupling of shear stress and interfacial pressure,resulting in the interfacial plastic zone shown as an inverted“V”shape.The upward plastic flow in this direction is relatively weak,and only a small amount of flash is extruded from top of joint.Moreover,the wedge block and welding components at top of joint are always in un-steady friction stage,leading to nonuniform temperature field distribution and un-welded defects.According to the results of numerical simulation,high oscillating frequency combined with low pressure and small amplitude is considered as appropriate parameter selection scheme to improve the upward interfacial plastic flow at top of joint and suppress the un-welded defects.The results of thermo-physical simulation illustrate that continuous dynamic recrystallization(CDRX)induces the bonding of interface,accompanying by intense dislocation movement and creation of many low-angle grain boundaries.In the interfacial bonding area,grain orientation is random with relatively low texture density(5.0 mud)owing to CDRX.展开更多
Land use/cover change(LUCC)constitutes the spatial and temporal patterns of ecological security,and the construction of ecological networks is an effective way to ensure ecological security.Exploring the spatial and t...Land use/cover change(LUCC)constitutes the spatial and temporal patterns of ecological security,and the construction of ecological networks is an effective way to ensure ecological security.Exploring the spatial and temporal change characteristics of ecological network and analyzing the integrated relationship between LUCC and ecological security are crucial for ensuring regional ecological security.Gansu is one of the provinces with fragile ecological environment in China,and rapid changes in land use patterns in recent decades have threatened ecological security.Therefore,taking Gansu Province as the study area,this study simulated its land use pattern in 2050 using patch-generating land use simulation(PLUS)model based on the LUCC trend from 2000 to 2020 and integrated the LUCC into morphological spatial pattern analysis(MSPA)to identify ecological sources and extract the ecological corridors to construct ecological network using circuit theory.The results revealed that,according to the prediction results in 2050,the areas of cultivated land,forest land,grassland,water body,construction land,and unused land would be 63,447.52,39,510.80,148,115.18,4605.21,8368.89,and 161,752.40 km^(2),respectively.The number of ecological sources in Gansu Province would increase to 80,with a total area of 99,927.18 km^(2).The number of ecological corridors would increase to 191,with an estimated total length of 6120.66 km.Both ecological sources and ecological corridors showed a sparse distribution in the northwest and dense distribution in the southeast of the province at the spatial scale.The number of ecological pinch points would reach 312 and the total area would expect to increase to 842.84 km^(2),with the most pronounced increase in the Longdong region.Compared with 2020,the number and area of ecological barriers in 2050 would decrease significantly by 63 and 370.71 km^(2),respectively.In general,based on the prediction results,the connectivity of ecological network of Gansu Province would increase in 2050.To achieve the predicted ecological network in 2050,emphasis should be placed on the protection of cultivated land and ecological land,the establishment of ecological sources in desert areas,the reinforcement of the protection for existing ecological sources,and the construction of ecological corridors to enhance the stability of ecological network.This study provides valuable theoretical support and references for the future construction of ecological networks and regional land resource management decision-making.展开更多
文摘Modern metropolises are increasingly affected by air quality problems. Transportation is one of the largest sources of several pollutants emissions, such as nitrogen oxides (NOx) and carbon monoxide (CO). Today in the EU, vehicles' emissions are strictly limited by Euro 6 norm-Euro VI for heavy-duty vehicles-which is periodically upgraded. To match such limits, manufacturers are forced in developing new technologies to perform new sustainable vehicles design strategies, such as EVs and HEVs. Present work's aim is to provide the design of series-hybrid urban transportation bus, equipped with a novel thermal power unit, namely a small gas turbine, to exploit its cleaner combustion process in comparison with an ICE. The control logic is described, while the main drivetrain components are chosen, and suitable models from suppliers are selected as well. Then, some simulations of the resulting vehicle are performed on opportune drive cycles, using Advisor, a free software based on Matlab-Simulink environment, published by US' National Renewable Energy Laboratory (NREL). Two different final configurations are environmentally and economically analysed, with the thermal power unit being respectively fuelled by compressed natural gas (CNG) and liquefied petroleum gas (LPG). Both satisfy the Euro VI norms, showing a substantial emission reduction (-89% and -43% in CO and THC releases respectively) in comparison to pollutants' threshold values.
文摘In this paper we will see the model of Universe according to Dynamic Universe Model of Cosmology by visualizing various processes that are happening in the Universe as per experimental evidences. For simplifying the matter here, we will see in part 1: about the Galaxy life cycle, where the birth and death of Galaxies discussed. Probably Universe gives guidance for the movement of Galaxies. We call this Part 1: Thinking and Reproducing Universe or Mindless Universe? (Galaxy life cycle). We see every day Sun, Stars, Galaxies etc., dissipating enormous energy in the form of radiation by the way of fusion of Hydrogen to helium. So after sometime all the Hydrogen is spent and Universe will die, is it not? … Dynamic Universe Model says that the energy in the form of electromagnetic radiation passing grazingly near any gravitating mass changes in frequency and finally will convert into neutrinos (mass). Hence Dynamic Universe Model proposes another process where energy will be converted back into matter and the cycle energy to mass to energy continues, sustaining the Universe to maintain this present status for ever in this form something like a Steady state model without any expansion. This we will see in Part 2: Energy - Mass - Energy Cycle. After converting energy into mass “how various elements are formed and where they are formed?” will be next logical question. Dynamic Universe Model says that these various particles change into higher massive particles or may get bombarded into stars or planets and various elements are formed. Here we bifurcate the formation of elements into 6 processes. They are for Elementary particles and elements generated in frequency changing process, By Cosmic rays, By Small stars, By Large Stars, By Super Novae and Manmade elements By Neutron Stars. This we will discuss in Part 3: Nucleosynthesis.
文摘In this paper,the forecasting equations of a 2nd-order space-time differential remainder are deduced from the Navier-Stokes primitive equations and Eulerian operator by Taylor-series expansion.Here we introduce a cubic spline numerical model(Spline Model for short),which is with a quasi-Lagrangian time-split integration scheme of fitting cubic spline/bicubic surface to all physical variable fields in the atmospheric equations on spherical discrete latitude-longitude mesh.A new algorithm of"fitting cubic spline—time step integration—fitting cubic spline—……"is developed to determine their first-and2nd-order derivatives and their upstream points for time discrete integral to the governing equations in Spline Model.And the cubic spline function and its mathematical polarities are also discussed to understand the Spline Model’s mathematical foundation of numerical analysis.It is pointed out that the Spline Model has mathematical laws of"convergence"of the cubic spline functions contracting to the original functions as well as its 1st-order and 2nd-order derivatives.The"optimality"of the 2nd-order derivative of the cubic spline functions is optimal approximation to that of the original functions.In addition,a Hermite bicubic patch is equivalent to operate on a grid for a 2nd-order derivative variable field.Besides,the slopes and curvatures of a central difference are identified respectively,with a smoothing coefficient of 1/3,three-point smoothing of that of a cubic spline.Then the slopes and curvatures of a central difference are calculated from the smoothing coefficient 1/3 and three-point smoothing of that of a cubic spline,respectively.Furthermore,a global simulation case of adiabatic,non-frictional and"incompressible"model atmosphere is shown with the quasi-Lagrangian time integration by using a global Spline Model,whose initial condition comes from the NCEP reanalysis data,along with quasi-uniform latitude-longitude grids and the so-called"shallow atmosphere"Navier-Stokes primitive equations in the spherical coordinates.The Spline Model,which adopted the Navier-Stokes primitive equations and quasi-Lagrangian time-split integration scheme,provides an initial ideal case of global atmospheric circulation.In addition,considering the essentially non-linear atmospheric motions,the Spline Model could judge reasonably well simple points of any smoothed variable field according to its fitting spline curvatures that must conform to its physical interpretation.
文摘We developed a detailed simulation model of the Arctic marine transport system(MTS) for oil platform Prirazlomnaya. The model has a multidisciplinary nature and involves: sub-models of various transport and technological processes; stochastic weather generator to obtain time series of 15 environmental parameters; and contextual planning algorithm to build voyage plan considering several types of ships and cargoes. We used a significant amount of real operational data to identify model parameters and to prove its statistical reliability. Our main scientific task is to investigate the interaction of various processes of a different nature, while the practical aim is to find a set of measures to increase the efficiency of MTS. The results of the study reveal many examples of the mutual interaction of various processes that need to be considered at the design stage to avoid technical mistakes.The study formed a basis for making managerial decisions at the top level of Gazprom Neft Shelf Company.
基金Supported by the Joint Fund for Enterprise Innovation and Development of the National Natural Science Foundation of China(U23B20154)General Program of the National Natural Science Foundation of China(42372169)。
文摘To address the challenges in studying the pore formation and evolution processes,and unclear preservation mechanisms of deep to ultra-deep carbonate rocks,a high-temperature and high-pressure visualization simulation experimental device was developed for ultra-deep carbonate reservoirs.Carbonate rock samples from the Sichuan Basin and Tarim Basin were used to simulate the dissolution-precipitation process of deep to ultra-deep carbonate reservoirs in an analogous geological setting.This unit comprises four core modules:an ultra-high temperature,high pressure triaxial stress core holder module(temperature higher than 300°C,pressure higher than 150 MPa),a multi-stage continuous flow module with temperature-pressure regulation,an ultra-high temperature-pressure sapphire window cell and an in-situ high-temperature-pressure fluid property measurement module and real-time ultra-high temperature-pressure permeability detection module.The new experimental device was used for simulation experiment,the geological insights were obtained in three aspects.First,the pore-throat structure of carbonate is controlled by lithology and initial pore-throat structure,and fluid type,concentration and dissolution duration determine the degree of dissolution.The dissolution process exhibits two evolution patterns.The dissolution scale is positively correlated to the temperature and pressure,and the pore-forming peak period aligns well with the hydrocarbon generation peak period.Second,the dissolution potential of dolomite in an open flow system is greater than that of limestone,and secondary dissolved pores formed continuously are controlled by the type and concentration of acidic fluids and the initial physical properties.These pores predominantly distribute along pre-existing pore/fracture zones.Third,in a nearly closed diagenetic system,after the chemical reaction between acidic fluids and carbonate rock reaches saturation and dynamic equilibrium,the pore structure no longer changes,keeping pre-existing pores well-preserved.These findings have important guiding significance for the evaluation of pore-throat structure and development potential of deep to ultra-deep carbonate reservoirs,and the prediction of main controlling factors and distribution of high-quality carbonate reservoirs.
文摘This paper deals with the increasing safety of working in aggressive potential locations, having SCADA system and WSN sensors, using a “probabilistic strategy” in comparison with a “deterministic” one, modeling/simulation and application in underground coal mining. In general, three conditions can be considered: 1) an unfriendly environment that facilitates the risk of accidents, 2) aggressive equipments that can compete to cause accidents and 3) the work security breaches that can cause accidents. These conditions define the triangle of accidents and are customized for an underground coal mining where the methane gas is released with the exploitation of the massive coal. In this case, the first two conditions create an explosive potential atmosphere. To allow people to work in a safe location it needs: first, a continuing monitoring through SCADA system of the explosive potential atmosphere and second, the use of antiexplosive equipment. This method, named “deterministic strategy”, increases the safety of working, but the explosions have not been completely eliminated. In order to increase the safety of working, the paper continues with the presentation of a new method based on hazard laws, named “probabilistic strategy”. This strategy was validated through modeling/simulation using CupCarbon software platform, and application of WSN networks implemented on Arduino equipments. At the end of the paper the interesting conclusions are emphases which are applicable to both strategies.
文摘提出了一种基于最小二乘支持向量机的织物剪切性能预测模型,并且采用遗传算法进行最小二乘支持向量机的参数优化,将获得的样本进行归一化处理后,将其输入预测模型以得到预测结果.仿真结果表明,基于最小二乘支持向量机的预测模型比BP神经网络和线性回归方法具有更高的精度和范化能力.
Abstract：
A new method is proposed to predict the fabric shearing property with least square support vector machines ( LS-SVM ). The genetic algorithm is investigated to select the parameters of LS-SVM models as a means of improving the LS- SVM prediction. After normalizing the sampling data, the sampling data are inputted into the model to gain the prediction result. The simulation results show the prediction model gives better forecasting accuracy and generalization ability than BP neural network and linear regression method.
基金Supported by the National Nature Science Foundation of China(60902061)the National Key Technology R&D Program (2008BAH28B06-05,2012BAH17F01)+1 种基金the National Culture S&T Promotion Program (WHB1002)the National High Iechnology Research and Development Drogram of China(863 Program) (2012AA011702)
文摘HB-MAP （HB-mutual authentication protocol） is a mutual ultra-light-weight authentication protocol we have pro- posed before. In this paper, we present an HB-MAP simulation model. This model is based on the OPNET modeler and includes three parts, namely, the network model, the node model, and the process model. The simulation results are obtained mainly in the aspects of running time, queuing delay, throughput, and channel utilization. To show the performance of HB-MAP, simulation of two other protocols HB and LCAP （load-based concurrent access protocol） is also executed, and comparative analysis is carried out on the results. At the end of the paper, we show a simple process of the attacks and identify that the HB-MAP can defend against some attacks.
基金Supported by the PetroChina Science and Technology Major Project(2016E-0101).
文摘The kinetic parameters of hydrocarbon generation are determined through experimental simulation and mathematical calculation using four typical samples selected from the Cretaceous Nenjiang Formation in the northwest of Songliao Basin,Chang 7 Member of Triassic Yanchang Formation in the southwest of Ordos Basin,Paleogene in the southwest of Qaidam Basin,and Lucaogou Formation of Jimusar Sag in the east of Junggar Basin.The results show that activation energy of hydrocarbon generation of organic matter is closely related to maturity and mainly ranges between 197 kJ/mol and 227 kJ/mol.On this basis,the temperature required for organic matter in shale to convert into oil was calculated.The ideal heating temperature is between 270℃and 300℃,and the conversation rate can reach 90%after 50-300 days of heating at constant temperature.When the temperature rises at a constant rate,the temperature corresponding to the major hydrocarbon generation period ranges from 225 to 350℃at the temperature rise rate of 1-150℃/month.In order to obtain higher economic benefits,it is suggested to adopt higher temperature rise rate(60-150℃/month).The more reliable kinetic parameters obtained can provide a basis for designing more reasonable scheme of in-situ heating conversion.
文摘Fiber-reinforced polymer(FRP)composites are renowned for their high mechanical strength,durability,and lightweight properties,making them integral to civil engineering,aerospace,and automotive manufacturing.Traditionally,the simulation and optimization of FRP materials have relied on finite element(FE)methods,which,while effective,often fall short in capturing the intricate behaviors of these composites under diverse conditions.Concrete examples in this regard involve modeling interfacial cracks,delaminations,or environmental effects that involve nonlinear phenomena.These degradation mechanisms exceed the capacity of classical FE models,as they are not detailed to the required level of detail.This aspect increases the time and computational resources required,leading to a need for optimization regarding fiber reinforcement configurations or multiple scenario load analysis.Thus,FE methods are inefficient compared to AI-based approaches that generalize material behavior based on extensive datasets.The advent of artificial intelligence(AI)has introduced advanced tools capable of enhancing the analysis and design of FRP materials.This review examines the current landscape of AI applications in FRP composite simulations,highlighting existing research gaps.Through a comprehensive bibliometric analysis,the study underscores the limited number of investigations focused on leveraging AI for FRP optimization.Furthermore,it synthesizes findings related to AI-driven simulation techniques,the mechanical properties of FRP composites,and strategies for predicting and improving their durability.This review comprehensively explores the potential of AI to overcome these limitations by synthesizing over 170 scientific works published between 2015 and 2025.Key findings highlight that supervised learning methods—especially neural networks,support vector machines,and gradient boosting models—achieve prediction accuracies above 90%for mechanical properties and defect classification.However,bibliometric analysis reveals that there are limited studies that address AI-driven optimization or standardized datasets for FRP applications.This review identifies eight core classification domains and eight regression domains where AI excels,including defect detection,bond strength prediction,and fiber orientation optimization.
基金supported by the Open Research Fund of Key Laboratory of Geological Hazards on Three Gorges Reservoir Area(China Three Gorges University),Ministry of Education(No.2022KDZ03)the Science and Technology Projects of Yunnan Provincial Science and Technology Department(No.202401AT070328)+1 种基金the Young talents project of“Xingdian Talent Support Program”in Yunnan Province(No.YNWR-QNBJ-2020-019)the Fund Project of China Academy of Railway Sciences Co.,Ltd.(No.2021YJ178)。
文摘0 INTRODUCTION In recent years,modern railways have been actively under construction in the complex mountainous area of Southwest China.However,rockfall poses a significant threat to both construction and operation phases of railway projects(Yan et al.,2023;Chen et al.,2022;Fanos and Pradhan,2018).
基金supported by the National Key Research and Development Program of China (Grant Nos. 2022YFA1404204 and 2022YFA1403700)the National Natural Science Foundation of China (Grant Nos. 12274086, 11534001 and 11925402)+5 种基金funding from the National Science Foundation of China (Grant Nos. 12274046, 11874094, 12147102, and 12347101)Chongqing Natural Science Foundation (Grant No. CSTB2022NSCQ-JQX0018)the Fundamental Research Funds for the Central Universities (Grant No. 2021CDJZYJH-003)Xiaomi Foundation/Xiaomi Young Talents Programthe supports of the start-up funding of Westlake Universitysupport from the Natural Sciences and Engineering Research Council of Canada (NSERC) through Discovery Grants。
文摘Simulating U(1) quantum gauge theories with spatial dimensions greater than one is of great physical significance. Here we propose a simple realization of U(1) gauge theory with Rydberg and Rydberg-dressed atom arrays. Within the experimentally accessible range, we find that the various aspects of the U(1) gauge theory can be well simulated, such as the emergence of topological sectors, incommensurability, and the Rokhsar–Kivelson point that hosts deconfined charge excitations and degenerate topological sectors. Our proposal is promising to implement experimentally and exhibits pronounced quantum dynamics.
基金supported by the Priority Program SPP 1992 of the German Science Foundation(DFG)The Diversity of Exoplanets under project number 362460292.
文摘We calculate the electrical and thermal conductivity of hydrogen for a wide range of densities and temperatures by using molecular dynamics simulations informed by density functional theory.On the basis of the corresponding extended ab initio data set,we construct interpolation formulas covering the range from low-density,high-temperature to high-density,low-temperature plasmas.Our conductivity model repro-duces the well-known limits of the Spitzer and Ziman theory.We compare with available experimental data andfind very good agreement.The new conductivity model can be applied,for example,in dynamo simulations for magneticfield generation in gas giant planets,brown dwarfs,and stellar envelopes.
文摘Numerical simulation of diode-pumped Q-switched Nd:YAG laser leading to the generation of eye-safe signal in singly resonant Intracavity Optical Parametric Oscillator (IOPO) is presented. Starting from rate equations, the time dependent laser equations have been solved numerically, whereas the space-dependent OPO equations analytically. Our results show that 1.4 J diode laser (810 nm) pulse with 200 msec width, delivers 30 mJ Nd:YAG laser (1064 nm) pulse with 5 n-second width. This Nd:YAG laser further generates 9 mJ eye safe signal (1570 nm) pulse with 2.5 n-second width.
基金The Deanship of Scientific Research(DSR)at King Abdulaziz University(KAU),Jeddah,Saudi Arabia,has funded this project under Grant No.(KEP-PhD:72-130-1443).
文摘The Underwater Communication Link(UCL)is a crucial component of Underwater Wireless Optical Communication(UWOC)systems,requiring optimised design to mitigate the high power attenuation inherent in seawater.To ensure the reliability of an optimal UCL design,it is essential to account for the three primary scattering regimes:forward scattering(FSC),backward scattering(BSC),and isotropic scattering(ISC)in seawater channels.This study introduces a new photon-tracking model based on a discrete equation,facilitating Monte Carlo Simulation(MCS)to evaluate how different scattering regimes influence received photon distribution.Three distinct Scattering Regime Contribution Weight(SRCW)probability sets were employed,each representing different UCL operational configurations dominated by specific scattering regimes.The proposed modeling approach enables a comprehensive assessment of the temporal characteristics of received optical pulses,channel loss,and time spread-ultimately defining the optimal UCL design parameters.The key findings of this study include:(1)Enhancing the FSC regime dominance leads to a quasi-light waveguide effect over link spans and small Fields of View(FOV)<25°,significantly improving channel performance in Harbor seawater compared to Coastal seawater.(2)A well-designed UCL with a small FOV(<25°)can minimise channel loss and time spread,ensuring high capacity and efficient performance in both Coastal and Harbor seawaters.(3)When BSC and ISC contributions exceed FSC dominance,the received optical pulse undergoes significant temporal broadening,particularly for larger FOV angles(>25°)and extended link spans.(4)The developed novel MCS-based discrete equation provides a simple yet robust model for simulating photon propagation in both homogeneous and inhomogeneous underwater channels.These insights contribute to developing more efficient and reliable UCL designs with military standards by enhancing UWOC system performance over a longer linkspan for a given limited optical power across various underwater environments.
基金Supported by the National Key Projects for Fundamental Research and Development of China(2016YFB0600904)
文摘Large quantities of blast furnace(BF) slag and CO_2 are discharged annually from iron and steel industries, along with a large amount of waste heat.The mineral carbonation of BF slag can not only reduce emissions of solid waste but also realize the in-situ fixation of CO_2 with low energy consumption if integrated with the waste heat utilization.In this study, based on our previous works, Aspen Plus was employed to simulate and optimize the carbonation process and integrate the process energy.The effects of gehlenite extraction, MgSO_4 carbonation,and aluminum ammonium sulfate crystallization were studied systematically.The simulation results demonstrate that 2.57 kg of BF slag can sequester 1 kg of CO_2, requiring 5.34 MJ of energy(3.3 MJ heat and 2.04 MJ electricity), and this energy includes the capture of CO_2 from industrial flue gases.Approximately 60 kg net CO_2 emission reduction could be achieved for the disposal of one ton of BF slag.In addition, the by-product,aluminum ammonium sulfate, is a high value-added product.Preliminary economic analysis indicates that the profit for the whole process is 1127 CNY per ton of BF slag processed.
基金co-supported by the National Natural Science Foundation of China(Nos.52105411,52105400and 52305420)the China Postdoctoral Science Foundation(No.2023M742830)Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX2023008).
文摘In this study,a new linear friction welding(LFW)process,embedded LFW process,was put forward,which was mainly applied to combination manufacturing of long or overlong loadcarrying titanium alloy structural components in aircraft.The interfacial plastic flow behavior and bonding mechanism of this process were investigated by a developed coupling EulerianLagrangian numerical model using software ABAQUS and a novel thermo-physical simulation method with designed embedded hot compression specimen.In addition,the formation mechanism and control method of welding defects caused by uneven plastic flow were discussed.The results reveal that the plastic flow along oscillating direction of this process is even and sufficient.In the direction perpendicular to oscillation,thermo-plastic metals mainly flow downward along welding interface under coupling of shear stress and interfacial pressure,resulting in the interfacial plastic zone shown as an inverted“V”shape.The upward plastic flow in this direction is relatively weak,and only a small amount of flash is extruded from top of joint.Moreover,the wedge block and welding components at top of joint are always in un-steady friction stage,leading to nonuniform temperature field distribution and un-welded defects.According to the results of numerical simulation,high oscillating frequency combined with low pressure and small amplitude is considered as appropriate parameter selection scheme to improve the upward interfacial plastic flow at top of joint and suppress the un-welded defects.The results of thermo-physical simulation illustrate that continuous dynamic recrystallization(CDRX)induces the bonding of interface,accompanying by intense dislocation movement and creation of many low-angle grain boundaries.In the interfacial bonding area,grain orientation is random with relatively low texture density(5.0 mud)owing to CDRX.
基金supported by the Science Fund for the Gansu Provincial Natural Science Foundation Project(22JR5RA339).
文摘Land use/cover change(LUCC)constitutes the spatial and temporal patterns of ecological security,and the construction of ecological networks is an effective way to ensure ecological security.Exploring the spatial and temporal change characteristics of ecological network and analyzing the integrated relationship between LUCC and ecological security are crucial for ensuring regional ecological security.Gansu is one of the provinces with fragile ecological environment in China,and rapid changes in land use patterns in recent decades have threatened ecological security.Therefore,taking Gansu Province as the study area,this study simulated its land use pattern in 2050 using patch-generating land use simulation(PLUS)model based on the LUCC trend from 2000 to 2020 and integrated the LUCC into morphological spatial pattern analysis(MSPA)to identify ecological sources and extract the ecological corridors to construct ecological network using circuit theory.The results revealed that,according to the prediction results in 2050,the areas of cultivated land,forest land,grassland,water body,construction land,and unused land would be 63,447.52,39,510.80,148,115.18,4605.21,8368.89,and 161,752.40 km^(2),respectively.The number of ecological sources in Gansu Province would increase to 80,with a total area of 99,927.18 km^(2).The number of ecological corridors would increase to 191,with an estimated total length of 6120.66 km.Both ecological sources and ecological corridors showed a sparse distribution in the northwest and dense distribution in the southeast of the province at the spatial scale.The number of ecological pinch points would reach 312 and the total area would expect to increase to 842.84 km^(2),with the most pronounced increase in the Longdong region.Compared with 2020,the number and area of ecological barriers in 2050 would decrease significantly by 63 and 370.71 km^(2),respectively.In general,based on the prediction results,the connectivity of ecological network of Gansu Province would increase in 2050.To achieve the predicted ecological network in 2050,emphasis should be placed on the protection of cultivated land and ecological land,the establishment of ecological sources in desert areas,the reinforcement of the protection for existing ecological sources,and the construction of ecological corridors to enhance the stability of ecological network.This study provides valuable theoretical support and references for the future construction of ecological networks and regional land resource management decision-making.
