Investigations of methane adsorption characteristics on marine-continental transitional shales and gas storage capacity models considering pore evolution

Methane adsorption is a critical assessment of the gas storage capacity(GSC)of shales with geological conditions.Although the related research of marine shales has been well-illustrated,the methane adsorption of marine-continental transitional(MCT)shales is still ambiguous.In this study,a method of combining experimental data with analytical models was used to investigate the methane adsorption characteristics and GSC of MCT shales collected from the Qinshui Basin,China.The Ono-Kondo model was used to fit the adsorption data to obtain the adsorption parameters.Subsequently,the geological model of GSC based on pore evolution was constructed using a representative shale sample with a total organic carbon(TOC)content of 1.71%,and the effects of reservoir pressure coefficient and water saturation on GSC were explored.In experimental results,compared to the composition of the MCT shale,the pore structure dominates the methane adsorption,and meanwhile,the maturity mainly governs the pore structure.Besides,maturity in the middle-eastern region of the Qinshui Basin shows a strong positive correlation with burial depth.The two parameters,micropore pore volume and non-micropore surface area,induce a good fit for the adsorption capacity data of the shale.In simulation results,the depth,pressure coefficient,and water saturation of the shale all affect the GSC.It demonstrates a promising shale gas potential of the MCT shale in a deeper block,especially with low water saturation.Specifically,the economic feasibility of shale gas could be a major consideration for the shale with a depth of<800 m and/or water saturation>60%in the Yushe-Wuxiang area.This study provides a valuable reference for the reservoir evaluation and favorable block search of MCT shale gas.

A Well Productivity Model for Multi-Layered Marine and Continental Transitional Reservoirs with Complex Fracture Networks

Using the typical characteristics of multi-layered marine and continental transitional gas reservoirs as a basis,a model is developed to predict the related well production rate.This model relies on the fractal theory of tortuous capillary bundles and can take into account multiple gas flow mechanisms at the micrometer and nanometer scales,as well as the flow characteristics in different types of thin layers(tight sandstone gas,shale gas,and coalbed gas).Moreover,a source-sink function concept and a pressure drop superposition principle are utilized to introduce a coupled flow model in the reservoir.A semi-analytical solution for the production rate is obtained using a matrix iteration method.A specific well is selected for fitting dynamic production data,and the calculation results show that the tight sandstone has the highest gas production per unit thickness compared with the other types of reservoirs.Moreover,desorption and diffusion of coalbed gas and shale gas can significantly contribute to gas production,and the daily production of these two gases decreases rapidly with decreasing reservoir pressure.Interestingly,the gas production from fractures exhibits an approximately U-shaped distribution,indicating the need to optimize the spacing between clusters during hydraulic fracturing to reduce the area of overlapping fracture control.The coal matrix water saturation significantly affects the coalbed gas production,with higher water saturation leading to lower production.

Noise-induced phase transition in the Vicsek model through eigen microstate methodology

This paper presents a comprehensive framework for analyzing phase transitions in collective models such as theVicsek model under various noise types. The Vicsek model, focusing on understanding the collective behaviors of socialanimals, is known due to its discontinuous phase transitions under vector noise. However, its behavior under scalar noiseremains less conclusive. Renowned for its efficacy in the analysis of complex systems under both equilibrium and nonequilibriumstates, the eigen microstate method is employed here for a quantitative examination of the phase transitions inthe Vicsek model under both vector and scalar noises. The study finds that the Vicsek model exhibits discontinuous phasetransitions regardless of noise type. Furthermore, the dichotomy method is utilized to identify the critical points for thesephase transitions. A significant finding is the observed increase in the critical point for discontinuous phase transitions withescalation of population density.

Comparative study on phase transition behaviors of fractional molecular field theory and random-site Ising model

Fractional molecular field theory(FMFT)is a phenomenological theory that describes phase transitions in crystals with randomly distributed components,such as the relaxor-ferroelectrics and spin glasses.In order to verify the feasibility of this theory,this paper fits it to the Monte Carlo simulations of specific heat and susceptibility versus temperature of two-dimensional(2D)random-site Ising model(2D-RSIM).The results indicate that the FMFT deviates from the 2D-RSIM significantly.The main reason for the deviation is that the 2D-RSIM is a typical system of component random distribution,where the real order parameter is spatially heterogeneous and has no symmetry of space translation,but the basic assumption of FMFT means that the parameter is spatially uniform and has symmetry of space translation.

Modification of streamer-to-leader transition model based on radial thermal expansion in the sphere-plane gap discharge at high altitude

Historically,streamer-to-leader transition studies mainly focused on the rod-plane gap and low altitude analysis,with limited attention paid to the sphere-plane gap at high altitude analysis.In this work,sphere-plane gap discharge tests were carried out under the gap distance of 5 m at the Qinghai Ultra High Voltage(UHV)test base at an altitude of 2200 m.The experiments measured the physical parameters such as the discharge current,electric field intensity and instantaneous optical power.The duration of the dark period and the critical charge of streamer-toleader transition were obtained at high altitude.Based on radial thermal expansion of the streamer stem,we established a modified streamer-to-leader transition model of the sphere-plane gap discharge at high altitude,and calculated the stem temperature,stem radii and the duration of streamer-to-leader transition.Compared with the measured duration of sphere-plane electrode discharge at an altitude of 2200 m,the error rate of the modified model was 0.94%,while the classical model was 6.97%,demonstrating the effectiveness of the modified model.From the comparisons and analysis,several suggestions are proposed to improve the numerical model for further quantitative investigations of the leader inception.

Artificial neural network-based one-equation model for simulation of laminar-turbulent transitional flow

A mapping function between the Reynolds-averaged Navier-Stokes mean flow variables and transition intermittency factor is constructed by fully connected artificial neural network(ANN),which replaces the governing equation of the intermittency factor in transition-predictive Spalart-Allmaras(SA)-γmodel.By taking SA-γmodel as the benchmark,the present ANN model is trained at two airfoils with various angles of attack,Mach numbers and Reynolds numbers,and tested with unseen airfoils in different flow states.The a posteriori tests manifest that the mean pressure coefficient,skin friction coefficient,size of laminar separation bubble,mean streamwise velocity,Reynolds shear stress and lift/drag/moment coefficient from the present two-way coupling ANN model almost coincide with those from the benchmark SA-γmodel.Furthermore,the ANN model proves to exhibit a higher calculation efficiency and better convergence quality than traditional SA-γmodel.

Stability analysis of CO_(2)gas shielded welding short-circuit transition process based on GMAW dynamic model

Base on the arc phase and short-circuit phase and their relationship, the paper considers the changes of the extension of wire, the arc length, liquid bridge resistance and mass of liquid bridge, combines the improved “mass-spring” model with the loop model of welding power system, puts forward the critical judgment condition of droplet transition, and establishes a more accurate dynamic model for describing the short-circuit transition process. The dynamic changes of short-circuit transfer frequency, welding current and voltage, contact droplet and residual droplet equivalent radius and droplet equivalent radius at different wire feeding speeds were calculated and analyzed, and compared with the experimental results. It shows that the fluctuation of droplet displacement, velocity and wire extension length at the optimal arc starting point is the smallest. The smaller the initial liquid bridge curvature radius is, the better the stability of short-circuit transfer is.

Development of the Transitional Care Model for nursing care in China's Mainland:A literature review

Background:The Transitional Care Model(TCM)for nursing care has yet to be implemented in China despite its success in Western countries.However,rapid social changes have demanded an upgrade in the quality of nursing care;in 2010,the Chinese government has acknowledged the need to implement the TCM in China.Objective:This study has the following objectives:(1)perform a thorough review of the literature regarding the development and implementation of the TCM in China's Mainland within the past 5 years;(2)provide a comprehensive discussion of the current status,problems,and strategies related to the implementation of the TCM in China's Mainland;and(3)suggest strategies pertaining to the future of the TCM in China.Design:The current pertinent literature is systematically reviewed.Data sources:Systematic and manual searches in computerized databases for relevant studies regarding the TCM led to the inclusion of 26 papers in this review.Review methods:Abstracts that satisfied the inclusion criteria were reviewed independently by the two authors of this manuscript,and discrepancies were resolved through discussion.The same reviewers independently assessed the paper in its entirety for selected abstracts.Results:The present English literature reviewrevealed a paucity of updated information about the development and implementation of the TCM in China's Mainland.Nevertheless,the dramatic growth of the TCM in the past 5 years has had a vital impact within the society and in nursing development.This review also revealed numerous issues regarding the focus of the TCM.Overall implications for practiceandrecommendations for future researchare discussed.Conclusion:Despite the potential of this nursing model to have a successful and beneficial impact in China's Mainland,it remains an under-researched topic.Further research on education and training as well as premium policies for nurses under the TCM are needed.

Porosity model and pore evolution of transitional shales:an example from the Southern North China Basin

The evolution of shale reservoirs is mainly related to two functions:mechanical compaction controlled by ground stress and chemical compaction controlled by thermal effect.Thermal simulation experiments were conducted to simulate the chemical compaction of marine-continental transitional shale,and X-ray diffraction(XRD),CO2 adsorption,N2 adsorption and high-pressure mercury injection(MIP)were then used to characterize shale diagenesis and porosity.Moreover,simulations of mechanical compaction adhering to mathematical models were performed,and a shale compaction model was proposed considering clay content and kaolinite proportions.The advantage of this model is that the change in shale compressibility,which is caused by the transformation of clay minerals during thermal evolution,may be considered.The combination of the thermal simulation and compaction model may depict the interactions between chemical and mechanical compaction.Such interactions may then express the pore evolution of shale in actual conditions of formation.Accordingly,the obtained results demonstrated that shales having low kaolinite possess higher porosity at the same burial depth and clay mineral content,proving that other clay minerals such as illite-smectite mixed layers(I/S)and illite are conducive to the development of pores.Shales possessing a high clay mineral content have a higher porosity in shallow layers(<3500 m)and a lower porosity in deep layers(>3500 m).Both the amount and location of the increase in porosity differ at different geothermal gradients.High geothermal gradients favor the preservation of high porosity in shale at an appropriate Ro.The pore evolution of the marine-continental transitional shale is divided into five stages.Stage 2 possesses an Ro of 1.0%-1.6%and has high porosity along with a high specific surface area.Stage 3 has an Ro of 1.6%-2.0%and contains a higher porosity with a low specific surface area.Finally,Stage 4 has an Ro of 2.0%-2.9%with a low porosity and high specific surface area.

First-order quantum phase transition and entanglement in the Jaynes-Cummings model with a squeezed light

We study the quantum phase transition and entanglement in the Jaynes-Cummings model with squeezed light,utilize a special transformation method to obtain the analytical ground state of the model within the near-resonance regime,and numerically verify the validity of the analytical ground state.It is found that the ground state exhibits a first-order quantum phase transition at the critical point linearly induced by squeezed light,and the ground state entanglement reaches its maximum when the qubit-field coupling strength is large enough at the critical point.

Analyzing Land-use Change in Farming-pastoral Transitional Region Using Autologistic Model and Household Survey Approach

Land change science （LCS） strives to understand and model land-use change, which will further advance the understanding of multiple issues in the socio-ecological systems. Based on GIS/RS techniques, autologistic model, and household survey method, this study investigated major land use changes and their causes from 1978 to 2008 in Uxin Banner （county-level）, Inner Mongolia in China and then developed an understanding of the relationships between household livelihood and land-use pattern. Results showed that cultivated land increased from 1988 to 2000, and leveled offafter 2000. Built-up land increased stably for the period 1978 2008. The change of grassland and bare land differed among the three periods. From 1978 to 1988, grassland increased by 23.3%, and bare land decreased by 20.48%. From 1988 to 2000, bare land expanded by 1.7%, but grassland declined by 1.3%. From 2000 to 2008, an increase in grassland area by 1.8% was observed, but a decrease in bare land area by 9.0% was witnessed. The autologistic models performed better than logistic models as indicated by lower Akaike Information Criterion （AIC） values. Factors associated with human activities significantly correlated with the change of cultivated land, forest land, grassland, and built-up land. The produce prices and extensive cultivated land use are major issues in the farming area. This study suggests that completing land circulation systems and maintaining the stability of price are effective solutions. By contrast, reclamation and overgrazing are major concerns in the pastoral areas. Implementing environmental policies effectively, transferring population out of rural pastoral areas, and developing modem animal husbandry are effective ways to address these issues.

Emergent topological ordered phase for the Ising-XY model revealed by cluster-updating Monte Carlo method

The two-component cold atom systems with anisotropic hopping amplitudes can be phenomenologically described by a two-dimensional Ising-XY coupled model with spatial anisotropy.At low temperatures,theoretical predictions[Phys.Rev.A 72053604(2005)]and[arXiv:0706.1609]indicate the existence of a topological ordered phase characterized by Ising and XY disorder but with 2XY ordering.However,due to ergodic difficulties faced by Monte Carlo methods at low temperatures,this topological phase has not been numerically explored.We propose a linear cluster updating Monte Carlo method,which flips spins without rejection in the anisotropy limit but does not change the energy.Using this scheme and conventional Monte Carlo methods,we succeed in revealing the nature of topological phases with half-vortices and domain walls.In the constructed global phase diagram,Ising and XY-type transitions are very close to each other and differ significantly from the schematic phase diagram reported earlier.We also propose and explore a wide range of quantities,including magnetism,superfluidity,specific heat,susceptibility,and even percolation susceptibility,and obtain consistent and reliable results.Furthermore,we observed first-order transitions characterized by common intersection points in magnetizations for different system sizes,as opposed to the conventional phase transition where Binder cumulants of various sizes share common intersections.The critical exponents of different types of phase transitions are reasonably fitted.The results are useful to help cold atom experiments explore the half-vortex topological phase.

Farm buildings and agri-food transitions in Southern France:Mapping dynamics using a stakeholder-based diagnosis

This study's goal is to present a dynamic portrait of the farm-buildings environment in Occitania,in Southern France,in order to better identify the transitions underway in agri-food chains.To this end,we undertook a ter-ritorial diagnosis based on actor statements,using 28 semi-structured interviews across Occitania.This diagnosis was enriched by graphic modelling,which enabled the spatialization of the dynamics described.We show that the process of standardisation of farm buildings prevails in the majority of the territories studied.This phenomenon has intensified in recent years with the development of vast photovoltaic-roofed sheds,accentuating the farm-land conversion and soil sealing.At the same time,in areas with strong environmental,landscape and heritage contexts,a'new adventure in farm buildings'(2022 survey)is taking shape.It is primarily driven by local short food chains,which rely on self-construction,repurposing and refurbishment,the sharing of tools and equipment,and which favour the use and reuse of local resources.This study shows that farm-buildings dynamics crystallise many challenges confronting the reterritorialisation of agriculture and food production.

Discrete Element Modelling of Damage Evolution of Concrete Considering Meso-Structure of ITZ

The mechanical properties of interfacial transition zones(ITZs)have traditionally been simplified by reducing the stiffness of cement in previous simulation methods.A novel approach based on the discrete element method(DEM)has been developed for modeling concrete.This new approach efficiently simulates the meso-structure of ITZs,accurately capturing their heterogeneous properties.Validation against established uniaxial compression experiments confirms the precision of thismodel.The proposedmodel canmodel the process of damage evolution containing cracks initiation,propagation and penetration.Under increasing loads,cracks within ITZs progressively accumulate,culminating in macroscopic fractures that traverse themortarmatrix,forming the complex,serpentine path of cracks.This study reveals four distinct displacement patterns:tensile compliant,tensile opposite,mixed tensile-shear,and shear opposite patterns,each indicative of different stages in concrete’s damage evolution.The widening angle of these patterns delineates the progression of cracks,with the tensile compliant pattern signaling the initial crack appearance and the shear opposite pattern indicating the concrete model’s ultimate failure.

Study on theoretical model for electrical explosion resistivity of Al/Ni reactive multilayer foil

Al/Ni reactive multilayer foil(RMF)possesses excellent comprehensive properties as a promising substitute for traditional Cu bridge.A theoretical resistivity model of Al/Ni RMF was developed to guide the optimization of EFIs.Al/Ni RMF with different bilayer thicknesses and bridge dimensions were prepared by MEMS technology and electrical explosion tests were carried out.According to physical and chemical reactions in bridge,the electrical explosion process was divided into 5 stages:heating of condensed bridge,vaporization and diffusion of Al layers,intermetallic combination reaction,intrinsic explosion,ionization of metal gases,which are obviously shown in measured voltage curve.Effects of interface and grain boundary scattering on the resistivity of film metal were considered.Focusing on variations of substance and state,the resistivity was developed as a function of temperature at each stage.Electrical explosion curves were calculated by this model at different bilayer thicknesses,bridge dimensions and capacitor voltages,which showed an excellent agreement with experimental ones.

Development of a new irradiation-embrittlement prediction model for reactor pressure-vessel steels

Predicting the transition-temperature shift(TTS)induced by neutron irradiation in reactor pressure-vessel(RPV)steels is important for the evaluation and extension of nuclear power-plant lifetimes.Current prediction models may fail to properly describe the embrittlement trend curves of Chinese domestic RPV steels with relatively low Cu content.Based on the screened surveillance data of Chinese domestic and similar international RPV steels,we have developed a new fluencedependent model for predicting the irradiation-embrittlement trend.The fast neutron fluence(E>1 MeV)exhibited the highest correlation coefficient with the measured TTS data;thus,it is a crucial parameter in the prediction model.The chemical composition has little relevance to the TTS residual calculated by the fluence-dependent model.The results show that the newly developed model with a simple power-law functional form of the neutron fluence is suitable for predicting the irradiation-embrittlement trend of Chinese domestic RPVs,regardless of the effect of the chemical composition.

Modeling and Analysis of Transitional Tube with Constant Sectional Area along Derivative Central Route

Firstly, sample square-circular transition tube along straight central route was modeled on CATIA software. The parameters are as follows： let the tube length is L, and the constant cross section area is S, and S = πR^2 = a2, in which R stands for the circle radius on one end, and a the square side length on the other end; set up the coordinate system with OX axis on the central route in which the origin O is on centroid of the square end and assume the cross section size at x as the square shaped with all four comers filleted in radius r which is proportional to x, that is, the linear slope of r is R/L, thus, both values r and square side length ax can be attained on the constant cross section area assumption. Secondly, some sample polygonal-circular transition tubes along straight, circular and helical central route were implemented similarly. Thirdly, numerical analysis of stress and displacement of these tubes were carried out on MSC/PATRAN software which are important to the distribution of turbulent flow and the layout of these transitional tube structures.

Short-term inbound rail transit passenger flow prediction based on BILSTM model and influence factor analysis

Accurate and real-time passenger flow prediction of rail transit is an important part of intelligent transportation systems(ITS).According to previous studies,it is found that the prediction effect of a single model is not good for datasets with large changes in passenger flow characteristics and the deep learning model with added influencing factors has better prediction accuracy.In order to provide persuasive passenger flow forecast data for ITS,a deep learning model considering the influencing factors is proposed in this paper.In view of the lack of objective analysis on the selection of influencing factors by predecessors,this paper uses analytic hierarchy processes(AHP)and one-way ANOVA analysis to scientifically select the factor of time characteristics,which classifies and gives weight to the hourly passenger flow through Duncan test.Then,combining the time weight,BILSTM based model considering the hourly travel characteristics factors is proposed.The model performance is verified through the inbound passenger flow of Ningbo rail transit.The proposed model is compared with many current mainstream deep learning algorithms,the effectiveness of the BILSTM model considering influencing factors is validated.Through comparison and analysis with various evaluation indicators and other deep learning models,the results show that the R2 score of the BILSTM model considering influencing factors reaches 0.968,and the MAE value of the BILSTM model without adding influencing factors decreases by 45.61%.

Calculating the number of radial cracks around a wellbore fractured by liquid CO2 phase transition blasting technology

Integrating liquid CO_(2)phase transition blasting(LCPTB)technology with hydraulic fracturing(HF)methods can help reduce wellbore damage,create multiple radial fractures,and establish a complex fracture network.This approach significantly increases the recovery efficiency of low-permeability oil and gas fields.Accurately calculating the number of fractures caused by LCPTB is necessary to predict production enhancement effects and optimize subsequent HF designs.However,few studies are reported on large-scale physical model experiments in terms of a method for calculating the fracture number.This study analyzed the initiation and propagation of cracks under LCPTB,derived a calculation formula for crack propagation radius under stress waves,and then proposed a new,fast,and accurate method for calculating the fracture number using the principle of mass conservation.Through ten rock-breaking tests using LCPTB,the study confirmed the effectiveness of the proposed calculation approach and elucidated the variation rule of explosion pressure,rock-breaking scenario,and the impact of varying parameters on fracture number.The results show that the new calculation method is suitable for fracturing technologies with high pressure rates.Recommendations include enlarging the diameter of the fracturing tube and increasing the liquid CO2 mass in the tube to enhance fracture effectiveness.Moreover,the method can be applied to other fracturing technologies,such as explosive fracturing(EF)within HF formations,indicating its broader applicability and potential impact on optimizing unconventional resource extraction technologies.

Does China's digital economy contribute to low-carbon transition?

The digital economy,as a new emerging economic form,has become an important power for realizing Chinese-style modernization and promoting green development in China.This paper measures the digital economy and low-carbon transition index based on the data of 30 provinces in China from 2013 to 2020 and analyzes the mechanism and path of the digital economy affecting low-carbon transition using the fixed effect panel data model and the threshold effect model.It is found that,(1)The digital economy and low-carbon transition in China are various in different regions,with characteristics of being unbalanced and insufficient.(2)The digital economy significantly promotes low-carbon transition,with the greatest influence in the Central region,followed by the Eastern region and the Western region.Under different dimensions,the development of informatization and digital transactions promote low-carbon transition,but the development of the internet plays an inhibiting role.(3)The higher the degree of urbanization and environmental regulation,the greater the influence of the digital economy on low-carbon transition.