With the continuous development of the offshore wind industry,the design concept of composite foundation has been given attention in the past decade.This paper presents an accurate method for investigating the horizon...With the continuous development of the offshore wind industry,the design concept of composite foundation has been given attention in the past decade.This paper presents an accurate method for investigating the horizontal vibration of monopile-friction wheel composite foundations in layered saturated soil.Firstly,the three-dimensional continuum mechanics theory with the range of linear elasticity is introduced to calculate the frictional resistance distributed on the upper soil surface.Then,the resistances of multilayered soils and inviscid seawater to the pile shaft under horizontal harmonic excitation are obtained using Novak's plane strain model,Biot's porous media theory and radiationwave theory.Thirdly,the expressions for the deformation,bending moment and internal force of the Euler-Bernoulli pile are derived using the boundary conditions with definitephysical meaning and transfer matrix method.By comparing with the results of 1g laboratory test and the idealized formula reported by the literature,the rationality and accuracy of the developed dynamical model can be verified.Finally,this paper conducts a series of worked examples to investigate the influencesof the elastic modulus and thickness of three-layer saturated soil and the location of interlayer soil on the horizontal dynamic vibration of composite foundation.The results show that an increase in elastic modulus of the surface soil is an effective way to improve the dynamic stability of the composite foundation in service conditions.The conclusions drawn from the numerical examples can develop some guidelines for the current foundation design of offshore wind turbines.展开更多
AIM:To evaluate the clinical outcomes of a new minimally invasive technique using horizontal mattress sutures and Hoffman pockets for four-point refixation of dislocated fourhaptic intraocular lenses(IOLs).METHODS:Thi...AIM:To evaluate the clinical outcomes of a new minimally invasive technique using horizontal mattress sutures and Hoffman pockets for four-point refixation of dislocated fourhaptic intraocular lenses(IOLs).METHODS:This retrospective consecutive case series included eyes with dislocated Akreos AO60 IOLs underwent scleral refixation using a horizontal mattress doubleneedle suture technique with intralamellar knot burial via Hoffman pockets.Clinical outcomes assessed included pre-and postoperative best-corrected visual acuity(BCVA),intraocular pressure(IOP),spherical equivalent(SE),suture duration,IOL centration,and perioperative complications.RESULTS:A total of 10 eyes from 10 patients(6 males)were included.The mean age at the time of IOL refixation was 53.10±13.07y(range:28-68y).The mean interval between initial IOL implantation and dislocation was 8.44±3.54y.The mean postoperative follow-up duration was 11.45±10.30mo.Surgical time averaged 15.3±1.77min,with no intraoperative complications.The mean axial length was 27.16±4.35 mm,with high myopia(HM)as the leading comorbidity(4/10 eyes).Postoperative BCVA significantly improved compared to preoperative values(P=0.025).Postoperative SE was significantly improved compared with preoperative(P=0.01).All IOLs remained centered throughout follow-up.CONCLUSION:This minimally invasive four-point scleral fixation technique offers a safe and effective refixation strategy for dislocated four-haptic IOLs.The horizontal mattress suture configuration combined with Hoffman pockets facilitates durable centration,avoids conjunctival dissection,and could be adopted into routine surgical practice.展开更多
Climate model prediction has been improved by enhancing model resolution as well as the implementation of sophisticated physical parameterization and refinement of data assimilation systems[section 6.1 in Wang et al.(...Climate model prediction has been improved by enhancing model resolution as well as the implementation of sophisticated physical parameterization and refinement of data assimilation systems[section 6.1 in Wang et al.(2025)].In relation to seasonal forecasting and climate projection in the East Asian summer monsoon season,proper simulation of the seasonal migration of rain bands by models is a challenging and limiting factor[section 7.1 in Wang et al.(2025)].展开更多
The Michelson Interferometer for Global High-resolution Thermospheric Imaging(MIGHTI)onboard the Ionospheric Connection Explorer(ICON)satellite offers the opportunity to investigate the altitude profile of thermospher...The Michelson Interferometer for Global High-resolution Thermospheric Imaging(MIGHTI)onboard the Ionospheric Connection Explorer(ICON)satellite offers the opportunity to investigate the altitude profile of thermospheric winds.In this study,we used the red-line measurements of MIGHTI to compare with the results estimated by Horizontal Wind Model 14(HWM14).The data selected included both the geomagnetic quiet period(December 2019 to August 2022)and the geomagnetic storm on August 26-28,2021.During the geomagnetic quiet period,the estimations of neutral winds from HWM14 showed relatively good agreement with the observations from ICON.According to the ICON observations,near the equator,zonal winds reverse from westward to eastward at around 06:00 local time(LT)at higher altitudes,and the stronger westward winds appear at later LTs at lower altitudes.At around 16:00 LT,eastward winds at 300 km reverse to westward,and vertical gradients of zonal winds similar to those at sunrise hours can be observed.In the middle latitudes,zonal winds reverse about 2-4 h earlier.Meridional winds vary more significantly than zonal winds with seasonal and latitudinal variations.According to the ICON observations,in the northern low latitudes,vertical reversals of meridional winds are found at 08:00-13:00 LT from 300 to 160 km and at around 18:00 LT from 300 to 200 km during the June solstice.Similar reversals of meridional winds are found at 04:00-07:00 LT from 300 to 160 km and at 22:00-02:00 LT from 270 to 200 km during the December solstice.In the southern low latitudes,meridional wind reversals occur at 08:00-11:00 LT from 200 to 160 km and at 21:00-02:00 LT from 300 to 200 km during the June solstice.During the December solstice,reversals of the meridional wind appear at 20:00-01:00 LT below 200 km and at 06:00-11:00 LT from 300 to 160 km.In the northern middle latitudes,the northward winds are dominant at 08:00-14:00 LT at 230 km during the June solstice.Northward winds persist until 16:00 LT at 160 and 300 km.During the December solstice,the northward winds are dominant from 06:00 to 21:00 LT.The vertical variations in neutral winds during the geomagnetic storm on August 26-28 were analyzed in detail.Both meridional and zonal winds during the active geomagnetic period observed by ICON show distinguishable vertical shear structures at different stages of the storm.On the dayside,during the main phase,the peak velocities of westward winds extend from a higher altitude to a lower altitude,whereas during the recovery phase,the peak velocities of the westward winds extend from lower altitudes to higher altitudes.The velocities of the southward winds are stronger at lower altitudes during the storm.These vertical structures of horizontal winds during the storm could not be reproduced by the HWM14 wind estimations,and the overall response to the storm of the horizontal winds in the low and middle latitudes is underestimated by HWM14.The ICON observations provide a good dataset for improving the HWM wind estimations in the middle and upper atmosphere,especially the vertical variations.展开更多
The effectiveness of horizontal well multi-stage and multi-cluster fracturing in the fractured soft coal seam roof for coalbed methane(CBM) extraction has been demonstrated.This study focuses on the geological charact...The effectiveness of horizontal well multi-stage and multi-cluster fracturing in the fractured soft coal seam roof for coalbed methane(CBM) extraction has been demonstrated.This study focuses on the geological characteristics of the No.5 and No.11 coal seams in the Hancheng Block,Ordos Basin,China.A multi-functional,variable-size rock sample mold capable of securing the wellbore was developed to simulate layered formations comprising strata of varying lithology and thicknesses.A novel segmented fracturing simulation method based on an expandable pipe plugging technique is proposed.Large-scale true triaxial experiments were conducted to investigate the effects of horizontal wellbore location,perforation strategy,roof lithology,and vertical stress difference on fracture propagation,hydraulic energy variation,and the stimulated reservoir volume in horizontal wells targeting the soft coal seam roof.The results indicate that bilateral downward perforation with a phase angle of 120° optimizes hydraulic energy conservation,reduces operational costs,enhances fracture formation,and prevents fracturing failure caused by coal powder generation and migration.This perforation mode is thus considered optimal for coal seam roof fracturing.When the roof consists of sandstone,each perforation cluster tends to initiate a single dominant fracture with a regular geometry.In contrast,hydraulic fractures formed in mudstone roofs display diverse morphology.Due to its high strength,the sandstone roof requires significantly higher pressure for crack initiation and propagation,whereas the mudstone roof,with its strong water sensitivity,exhibits lower fracturing pressures.To mitigate inter-cluster interference,cluster spacing in mudstone roofs should be greater than that in sandstone roofs.Horizontal wellbore placement critically influences fracturing effectiveness.For indirect fracturing in sandstone roofs,an optimal position is 25 mm away from the lithological interface.In contrast,the optimal location for indirect fracturing in mudstone roofs is directly at the lithological interface with the coal seam.Higher vertical stress coefficients lead to increased fractu ring pressures and promote vertical,layer-penetrating fractures.A coefficient of 0.5 is identified as optimal for achieving effective indirect fracturing.This study provides valuable insights for the design and optimization of staged fracturing in horizontal wells targeting crushed soft coal seam roofs.展开更多
Predicting the productivity of multistage fractured horizontal wells plays an important role in exploiting unconventional resources.In recent years,machine learning(ML)models have emerged as a new approach for such st...Predicting the productivity of multistage fractured horizontal wells plays an important role in exploiting unconventional resources.In recent years,machine learning(ML)models have emerged as a new approach for such studies.However,the scarcity of sufficient real data for model training often leads to imprecise predictions,even though the models trained with real data better characterize geological and engineering features.To tackle this issue,we propose an ML model that can obtain reliable results even with a small amount of data samples.Our model integrates the synthetic minority oversampling technique(SMOTE)to expand the data volume,the support vector machine(SVM)for model training,and the particle swarm optimization(PSO)algorithm for optimizing hyperparameters.To enhance the model performance,we conduct feature fusion and dimensionality reduction.Additionally,we examine the influences of different sample sizes and ML models for training.The proposed model demonstrates higher prediction accuracy and generalization ability,achieving a predicted R^(2)value of up to 0.9 for the test set,compared to the traditional ML techniques with an R^(2)of 0.13.This model accurately predicts the production of fractured horizontal wells even with limited samples,supplying an efficient tool for optimizing the production of unconventional resources.Importantly,the model holds the potential applicability to address similar challenges in other fields constrained by scarce data samples.展开更多
The horizontal ecological compensation plays an important role in balancing the interests of all parties and coordinating regional development in the basin.However,the mechanism of ecological compensation based on emb...The horizontal ecological compensation plays an important role in balancing the interests of all parties and coordinating regional development in the basin.However,the mechanism of ecological compensation based on embodied carbon emissions is still poorly understood.Here,taking the Yellow River Basin as the research area,we use the multi-regional input-output(MRIO)model to measure the embodied carbon transfers between its seven urban agglomerations in 2012 and 2017 from the viewpoint of value-added trade benefits.Further,for the first time,the green trade benefits and ecological compensation amounts are analyzed.The results indicate that:(1)The transfer of trade-embodied carbon among the urban agglomerations in the basin showed obvious spatial heterogeneity and geographic proximity effects,and trade-embodied carbon outflows(inflows)had a pattern of"highest in the midstream,second in the downstream,and lowest in the upstream".(2)The industry composition of the urban agglomerations in relation to embodied carbon outflows(inflows)was similar,mainly in the service and heavy manufacturing industries.(3)The spatial pattern of green trade benefits in the basin had shifted from"high in the north and low in the surrounding area"to"high in the east-central part and low in the west".(4)The pattern of ecological compensation in the basin had shifted from the upstream surplus,the middle and downstream deficit to the midstream deficit,and the upstream and downstream surplus.Therefore,we recommend improving energy structures in high-demand urban agglomerations by adopting clean energy,focusing on decarbonization and energy efficiency in resource-rich regions.Additionally,promoting low-carbon economies,especially in the service and heavy manufacturing industries,implementing differentiated emission reduction strategies,and optimizing carbon compensation mechanisms considering regional disparities and resource endowments are crucial.It is expected that the study can enrich the scientific basis of horizontal ecological compensation and increase the fairness of regional carbon emission rights allocation.展开更多
Zika virus(ZIKV)is a mosquito-borne virus belonging to the genus Orthoflavivirus,and the family Flaviviridae.It commonly presents with febrile-like symptoms,neurological issues,and pregnancy complications in humans.Cu...Zika virus(ZIKV)is a mosquito-borne virus belonging to the genus Orthoflavivirus,and the family Flaviviridae.It commonly presents with febrile-like symptoms,neurological issues,and pregnancy complications in humans.Currently,there is no commercial vaccine or specific treatment available to prevent ZIKV infection.Therefore,controlling the epidemic's spread relies on preventing mosquitoes from transmitting the virus.Although various studies have explored the transmission of ZIKV between mosquitoes and vertebrate hosts,comprehensive research on potential mosquito-to-mosquito transmission of ZIKV remains limited.In this study,we conducted systematic laboratory investigations to assess the ability of ZIKV to spread among mosquitoes,and to evaluate the impact of ZIKV infection on mosquito development.Our findings revealed that ZIKV can be transmitted between Aedes aegypti mosquitoes both vertically and horizontally,through oviposition and contact between mosquitoes of the same or opposite sex.Additionally,we observed that ZIKV infection resulted in a reduction in the number of mosquito eggs but an increase in their size.The widespread distribution of ZIKV in infected mosquitoes and the altered levels of hormone related genes following viral infection were noted,which may contribute to viral transmission among mosquitoes and affect mosquito development.This research provides systematic experimental evidence of ZIKV transmission among mosquitoes,which is crucial for developing novel strategies to disrupt the spread of orthoflaviviruses and other mosquitoborne pathogens.展开更多
Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress magnitude.To investigate the correlation between the rock mass properties and maximum horizontal stre...Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress magnitude.To investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution method.The results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with depth.There is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and messy.Moreover,there is no obvious relationship between the rock quality designation(RQD)and depth.The maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same depth.In addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data.展开更多
The escalating global dissemination of plasmid-mediated antibiotic resistance poses a formidable threat to global health.Conjugation stands as a pivotal mechanism for horizontal gene transfer among bacterial populatio...The escalating global dissemination of plasmid-mediated antibiotic resistance poses a formidable threat to global health.Conjugation stands as a pivotal mechanism for horizontal gene transfer among bacterial populations,facilitating the spread of antibiotic resistance genes(ARGs).Microelectrolysis has garnered attention as an efficacious strategy for mitigating antibiotic concentrations in wastewater,yet its potential impact on ARG horizontal transfer remain largely unexplored.This comprehensive investigation unveils that microelectrolysis not only influences but significantly accelerates the conjugative transfer of ARG-harboring plasmids.Remarkably,this phenomenon is corroborated at the microbial community scale,underscoring its ecological relevance.Alarmingly,the study highlights the vulnerability of intestinalmicroorganisms to acquire antibiotic resistance under electrolytic stimulation,posing heightened risks to both animal and human health.Delving deeper,the study elucidates the underlyingmechanisms responsible for this enhanced conjugative transfer.It reveals that microelectrolysis augments the abundance of mating-competent cells,triggers the generation of reactive oxygen species,inflicts modest membrane damage,and upregulates the expression of genes critical for conjugation.These findings collectively contribute to a more profound comprehension of the environmental dissemination dynamics and associated public health implications of ARGs in the context of wastewater treatment employing microelectrolytic technologies.展开更多
Time-averaged thermal convection in a rotating horizontal annulus with a higher temperature at its inner boundary is studied.The centrifugal force plays a stabilizing role,while thermal convection is determined by the...Time-averaged thermal convection in a rotating horizontal annulus with a higher temperature at its inner boundary is studied.The centrifugal force plays a stabilizing role,while thermal convection is determined by the“thermovibrational mechanism”.Convective flow is excited due to oscillations of a non-isothermal rotating fluid.Thermal vibrational convectionmanifests in the form of two-dimensional vortices elongated along the axis of rotation,which develop in a threshold manner with an increase in the amplitude of fluid oscillations.The objective of the present study is to clarify the nature of another phenomenon,i.e.,three-dimensional convective vortices observed in the experiments both before the excitation of the convection described above and in the supercritical region.The experimental study of the oscillatory and the time-averaged flow fields by particle image velocimetry is accompanied by the theoretical research of inertial waves.It is found that three-dimensional fluid flows owe their origin to inertial waves.This is confirmed by a high degree of agreement between the experimental and theoretical results.Experiments with cavities of different lengths indicate that the vortices are clearly seen in cavities thatmeet the conditions of resonant excitation of inertial modes.Furthermore,the length of the cavity has no effect on heat transfer,which is explained by the comparatively low intensity of the wave-induced flows.The main contribution to heat transfer is due to vortices elongated along the axis of rotation.The novel results are of significant practical importance in various fields.展开更多
The China Spallation Neutron Source(CSNS)is the fourth pulsed accelerator-driven neutron source in the world,and it achieved its design target of 100 kW in 2020.The planned China Spallation Neutron Source Phase II(CSN...The China Spallation Neutron Source(CSNS)is the fourth pulsed accelerator-driven neutron source in the world,and it achieved its design target of 100 kW in 2020.The planned China Spallation Neutron Source Phase II(CSNS-II)commenced in 2024.The CSNS-II linac design primarily involves the addition of a radio-frequency ion source and a section of a superconducting linear accelerator composed of two types of superconducting cavities,namely double-spoke and six-cell elliptical cavities,after the drift tube linac(DTL).The development of the double-spoke superconducting cavity began in early 2021,and by January 2023,the welding,post-processing,and vertical tests of two 324 MHz double-spoke cavity prototypes were completed,with vertical test gradients of 11.6 and 15 MV/m,and Q_(0)≥3×10^(10)@E_(acc)≤10 MV/m.The R&D of the cryomodule began in January 2022.In October 2023,the clean assembly of the double-spoke cavity string and cold mass installation of the cryomodule commenced,with the installation of the cryomodule and valve box completing in two months.In January 2024,a horizontal test of the cryomodule was completed,making it the first double-spoke cavity cryomodule in China.The test results showed that the maximum gradients of the two superconducting cavities at a pulse width of 4 ms and repetition frequency of 25 Hz were 12.8 and 15.2 MV/m,respectively.This article provides a detailed introduction to the double-spoke superconducting cavity,tuner,coupler,and cryomodule,elaborates on the clean assembly of the cavity string and cold mass installation of the cryomodule,and provides a detailed analysis of the horizontal test results.展开更多
Salt deposits in China predominantly originate from lake deposits,characterized by thin salt beds interspersed with numerous interlayers,collectively termed bedded salt formations.Historically,the solution mining prac...Salt deposits in China predominantly originate from lake deposits,characterized by thin salt beds interspersed with numerous interlayers,collectively termed bedded salt formations.Historically,the solution mining practices have adopted the layered solution mining approach,inspired by coal mining techniques.However,this approach fails to account for the unique challenges of salt solution mining.Practical implementation is inefficient,costs escalate post-construction,and cavern geometry is constrained by salt beds thickness.Additionally,resource loss in abandoned beds and stability risks in adjacent mining zones remain unresolved.This study investigates mining scheme selection for low-grade salt deposits in Huai'an Salt Basin,introducing a continuous solution mining method that traverses multiple interlayers.Through comprehensive analysis of plastic deformation in caverns and surrounding rock,volume shrinkage rates,and economic costs comparing continuous and layered solution mining approaches,the results demonstrate that:(1)In the layered solution mining with horizontal interconnected wells scheme,plastic deformation zones propagate unevenly,posing interlayer connectivity risks.Concurrently,roof subsidence and floor heave destabilize the structure;(2)the continuous solution mining with horizontal interconnected wells scheme reduces plastic deformation zones to 3.4%of cavern volume,with volumetric shrinkage below 17%,markedly improving stability;(3)Economically,the continuous solution mining scheme generates caverns 2.43 times larger than the layered solution mining,slashing unit volume costs to 41.1%while enhancing resource recovery and long-term viability.The continuous method demonstrates distinct economic advantages and achieves higher resource utilization efficiency in solution mining compared to layered mining.Furthermore,its superior cavern stability presents strong potential for large-scale implementation.展开更多
Hydraulic fracturing technology has played an important role in the exploitation of unconventional oil and gas resources,however,its application to gas hydrate reservoirs has been rarely studied.Currently,there is sti...Hydraulic fracturing technology has played an important role in the exploitation of unconventional oil and gas resources,however,its application to gas hydrate reservoirs has been rarely studied.Currently,there is still limited understanding of the propagation and extension of fractures around the wellbore during the fracturing process of horizontal wells in hydrate reservoirs,as well as the stress interference patterns between fractures.This study simulates hydraulic fracturing processes in hydrate reservoirs using a fluidsolid coupling discrete element method(DEM),and analyzes the impacts of hydrate saturation and geological and engineering factors on fracture extension and stress disturbance.The results show that hydraulic fracturing is more effective when hydrate saturation exceeds 30%and that fracture pressure increases with saturation.The increase in horizontal stress differential enhances the directionality of fracture propagation and reduces stress disturbance.The distribution uniformity index(DUI)reveals that injection pressure is directly proportional to the number of main fractures and inversely proportional to fracturing time,with fracturing efficiency depending on the spacing between injection points and the distance between wells.This work may provide reference for the commercial exploitation of natural gas hydrates.展开更多
To explore and evaluate the longitudinal utilization degree of marine shale gas horizontal wells in southern Sichuan Basin(hereinafter referred to as“southern Sichuan”),focusing on the shale of Wufeng formation-Long...To explore and evaluate the longitudinal utilization degree of marine shale gas horizontal wells in southern Sichuan Basin(hereinafter referred to as“southern Sichuan”),focusing on the shale of Wufeng formation-Longyi1 sub-member in the deep Z block.By using the data from core experiments,well logging,and fracture height detection,a systematic analysis from the perspectives of reservoir distribution,longitudinal utilization height of hydraulic fractures,and longitudinal utilization degree of horizontal wells was conducted.The research results show that:(1)The overall reservoir conditions of theWufeng formation-Longyi1 sub-member in the study area are relatively favorable,although the quality of Type Ⅰ reservoir varies significantly among different well blocks;(2)The proppant tracer fracture height detection results show that fractures tend to extend upwards,the average total fracture height of fracture extend is 12.7 m,with the average upward extension height is 2.5 times the downward extension height;(3)The combination of fracture height and gas well productivity analysis suggests that targeting sub-layer 1 as the horizontal well target can achieve full production of the continuous thickness of Type Ⅰ reservoir in Z2 well block,whereas in Z1 well block,due to the significant proportion of the Wufeng formation in the continuous thickness of Type Ⅰ reservoir,in the areas where the continuous thickness of Type Ⅰ reservoir in Wufeng formation to middle sub-layer 1 is greater than 4 m,horizontal wells cannot achieve full longitudinal utilization of the continuous thickness in top-quality Type Ⅰ reservoir.The conclusion is that due to the limitations of longitudinal utilization height by artificial fracture networks and the variability in the distribution of continuous thickness of Type Ⅰ reservoir,Z1 well block can continue to conduct horizontal well target tests and differentiated fracturing designs to further enhance the longitudinal utilization degree of the top-quality Type Ⅰ reservoir.展开更多
A flexible sidetracking stimulation technology of horizontal wells is formed to develop the lateral deep remaining oil and gas resources of the low-permeability mature oilfields.This technology first uses the flexible...A flexible sidetracking stimulation technology of horizontal wells is formed to develop the lateral deep remaining oil and gas resources of the low-permeability mature oilfields.This technology first uses the flexible sidetracking tool to achieve low-cost sidetracking in the old wellbore,and then uses the hydraulic jet technology to induce multiple fractures to fracture.Finally,the bullhead fracturing of multi-cluster temporary plugging for the sidetracking hole is carried out by running the tubing string,to realize the efficient development of the remaining reserves among the wells.The flexible sidetracking stimulation technology involves flexible sidetracking horizontal wells drilling and sidetracking horizontal well fracturing.The flexible sidetracking horizontal well drilling includes three aspects:flexible drill pipe structure and material optimization,drilling technology,and sealed coring tool.The sidetracking horizontal well fracturing includes two aspects:fracturing scheme optimization,fracturing tools and implementation process optimization.The technology has been conducted several rounds of field tests in the Ansai Oilfield of Changqing,China.The results show that by changing well type and reducing row spacing of oil and water wells,the pressure displacement system can be well established to achieve effective pressure transmission and to achieve the purpose of increasing liquid production in low-yield and low-efficiency wells.It is verified that the flexible sidetracking stimulation technology can provide favorable support for accurately developing remaining reserves in low-permeability reservoirs.展开更多
As an important part of offshore wind turbine support and fixed units, the multibucket jacket foundation bears large loads and a complex marine environment. In this paper, the horizontal bearing characteristics of the...As an important part of offshore wind turbine support and fixed units, the multibucket jacket foundation bears large loads and a complex marine environment. In this paper, the horizontal bearing characteristics of the four-bucket jacket foundation of offshore wind power in sandy soil are studied. Through model tests and numerical simulations, the influence of bucket foundation sealing properties, load application speed, and loading direction on foundation-bearing capacity are discussed. The results show that the horizontal ultimate bearing capacity of the foundation in the nonsealing condition is decreased by 51.3% compared with the sealing condition;therefore, after the foundation penetration construction is completed, the bucket sealing must be ensured to increase the load-bearing performance of the structure. At a loading speed of 3.25 mm/s, the horizontal ultimate bearing capacity of the foundation is increased by 9.4% over the working condition of 1.85 mm/s. The bearing capacity of the foundation is maximized in the loading direction α =45° and is the smallest when α =0°. That is, the foundation can maximize its loadbearing performance under the condition of single-bucket compression/tension. During the design process, the main load of the structure should be loaded in the 45° direction. The contrast error of the experiment and numerical simulation does not exceed 10%. The research results have important guiding importance for designing and constructing the jacket foundation and can be used as a reference for the stable operation and sustainable development of offshore wind power systems.展开更多
Measurements from a hyperspectral infrared(HIR) sounder onboard a satellite in geostationary orbit not only provide atmospheric thermodynamic information,but also can be used to infer dynamic information with high tem...Measurements from a hyperspectral infrared(HIR) sounder onboard a satellite in geostationary orbit not only provide atmospheric thermodynamic information,but also can be used to infer dynamic information with high temporal resolution.Radiance measurements from the Geostationary Interferometric Infrared Sounder(GIIRS),obtained with 15-min temporal resolution during Typhoon Maria(2018) and 30-min temporal resolution during Typhoon Lekima(2019),were used to derive three-dimensional(3D) horizontal winds by tracking the motion of atmospheric moisture.This work focused on the impact of assimilation of 3D winds on typhoon analyses and forecasts using the operational NWP model of the China Meteorological Administration(CMA-MESO),and improved understanding of the potential benefits of assimilating dynamic information from geostationary sounder data with higher temporal resolution.The standard deviation of the observations minus simulations revealed that the accuracy of the derived 3D winds with 15-min resolution was higher than that of derived winds with 30-min resolution.Experiments showed that the assimilation system can effectively absorb the information of the derived 3D winds,and that dynamic information from clear-sky areas can be transferred to typhoon areas.In typhoon prediction,assimilation of the derived 3D winds had greatest influence on the typhoon track,and less influence on the maximum wind speed.Assimilation of the derived 3D winds reduced the average track error by 17.4% for Typhoon Maria(2018) and by 3.5% for Typhoon Lekima(2019) during their entire 36-h forecasts initiated at different times.Assimilation of GIIRS dynamic information can substantially improve forecasts of heavy precipitation by CMAMESO.Results indicate that the assimilation of dynamic information from high-temporal-resolution geostationary HIR sounder data adds value for improved numerical weather prediction.展开更多
With the widespread application of com-munication technology in the non-terrestrial network(NTN),the issue of the insecure communication due to the inherent openness of the NTN is increasingly being recognized.Consequ...With the widespread application of com-munication technology in the non-terrestrial network(NTN),the issue of the insecure communication due to the inherent openness of the NTN is increasingly being recognized.Consequently,safeguarding com-munication information in the NTN has emerged as a critical challenge.To address this issue,we pro-pose a beamforming and horizontal trajectory joint op-timization method for unmanned aerial vehicle(UAV)covert communications in the NTN.First,we formu-late an optimization problem that considers constraints such as the transmitting power and the distance.More-over,we employ the integrated communication and jamming(ICAJ)signal as Alice’s transmitting signal,further protecting the content of communication in-formation.Next,we construct two subproblems,and we propose an alternate optimization(AO)algorithm based on quadratic transform and penalty term method to solve the proposed two subproblems.Simulation re-sults demonstrate that the proposed method is effective and has better performance than benchmarks.展开更多
In the rapidly evolving landscape of Industry 4.0(I4.0),the convergence of information and operational technologies necessitates real-time communication and collaboration across cyber-physical systems and the Internet...In the rapidly evolving landscape of Industry 4.0(I4.0),the convergence of information and operational technologies necessitates real-time communication and collaboration across cyber-physical systems and the Internet of Things(IoT).Rapid data transmission is particularly critical within enterprises(vertically)and among stakeholders(horizontally)in this complex,heterogeneous ecosystem.While current research has focused on data application,processing,and storage within the cloud-edge-device continuum,cross-edge transmission has received less attention,resulting in challenges such as suboptimal routing and excessive delays in horizontal communications.To address the above issues,this paper introduces a Connection-As-Required Scheme(CARS)specifically designed for delay-sensitive IoT and Cyber-Physical System(CPS)applications,where low-latency communication is essential for operational efficiency.CARS leverages Lyapunov optimization and backpressure algorithms to optimize traffic scheduling and routing,minimizing communication delay between entities.Benchmarking against state-of-the-art solutions,CARS reduces Round-Trip Time(RTT)to approximately 47.0%of conventional methods and decreases delay by 24.5%in TCP-based and 26.0%in UDP-based applications.These results highlight the potential of CARS to facilitate effective,low-latency collaboration in diverse I4.0 environments.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52178329),the China Scholarship Council(Grant No.202306130155)the Postgraduate Scientific Research Innovation Project of Hunan Province,China(Grant No.CX20230442).
文摘With the continuous development of the offshore wind industry,the design concept of composite foundation has been given attention in the past decade.This paper presents an accurate method for investigating the horizontal vibration of monopile-friction wheel composite foundations in layered saturated soil.Firstly,the three-dimensional continuum mechanics theory with the range of linear elasticity is introduced to calculate the frictional resistance distributed on the upper soil surface.Then,the resistances of multilayered soils and inviscid seawater to the pile shaft under horizontal harmonic excitation are obtained using Novak's plane strain model,Biot's porous media theory and radiationwave theory.Thirdly,the expressions for the deformation,bending moment and internal force of the Euler-Bernoulli pile are derived using the boundary conditions with definitephysical meaning and transfer matrix method.By comparing with the results of 1g laboratory test and the idealized formula reported by the literature,the rationality and accuracy of the developed dynamical model can be verified.Finally,this paper conducts a series of worked examples to investigate the influencesof the elastic modulus and thickness of three-layer saturated soil and the location of interlayer soil on the horizontal dynamic vibration of composite foundation.The results show that an increase in elastic modulus of the surface soil is an effective way to improve the dynamic stability of the composite foundation in service conditions.The conclusions drawn from the numerical examples can develop some guidelines for the current foundation design of offshore wind turbines.
文摘AIM:To evaluate the clinical outcomes of a new minimally invasive technique using horizontal mattress sutures and Hoffman pockets for four-point refixation of dislocated fourhaptic intraocular lenses(IOLs).METHODS:This retrospective consecutive case series included eyes with dislocated Akreos AO60 IOLs underwent scleral refixation using a horizontal mattress doubleneedle suture technique with intralamellar knot burial via Hoffman pockets.Clinical outcomes assessed included pre-and postoperative best-corrected visual acuity(BCVA),intraocular pressure(IOP),spherical equivalent(SE),suture duration,IOL centration,and perioperative complications.RESULTS:A total of 10 eyes from 10 patients(6 males)were included.The mean age at the time of IOL refixation was 53.10±13.07y(range:28-68y).The mean interval between initial IOL implantation and dislocation was 8.44±3.54y.The mean postoperative follow-up duration was 11.45±10.30mo.Surgical time averaged 15.3±1.77min,with no intraoperative complications.The mean axial length was 27.16±4.35 mm,with high myopia(HM)as the leading comorbidity(4/10 eyes).Postoperative BCVA significantly improved compared to preoperative values(P=0.025).Postoperative SE was significantly improved compared with preoperative(P=0.01).All IOLs remained centered throughout follow-up.CONCLUSION:This minimally invasive four-point scleral fixation technique offers a safe and effective refixation strategy for dislocated four-haptic IOLs.The horizontal mattress suture configuration combined with Hoffman pockets facilitates durable centration,avoids conjunctival dissection,and could be adopted into routine surgical practice.
文摘Climate model prediction has been improved by enhancing model resolution as well as the implementation of sophisticated physical parameterization and refinement of data assimilation systems[section 6.1 in Wang et al.(2025)].In relation to seasonal forecasting and climate projection in the East Asian summer monsoon season,proper simulation of the seasonal migration of rain bands by models is a challenging and limiting factor[section 7.1 in Wang et al.(2025)].
基金supported by the National Key R&D Program of China (Grant No.2022YFF0503700)the special funds of Hubei Luojia Laboratory (Grant No.220100011)+1 种基金supported by the International Space Science Institute–Beijing(ISSI-BJ) project“The Electromagnetic Data Validation and Scientific Application Research based on CSES Satellite”and ISSI/ISSI-BJ project,“Multi-Scale Magnetosphere–Ionosphere–Thermosphere Interaction.”
文摘The Michelson Interferometer for Global High-resolution Thermospheric Imaging(MIGHTI)onboard the Ionospheric Connection Explorer(ICON)satellite offers the opportunity to investigate the altitude profile of thermospheric winds.In this study,we used the red-line measurements of MIGHTI to compare with the results estimated by Horizontal Wind Model 14(HWM14).The data selected included both the geomagnetic quiet period(December 2019 to August 2022)and the geomagnetic storm on August 26-28,2021.During the geomagnetic quiet period,the estimations of neutral winds from HWM14 showed relatively good agreement with the observations from ICON.According to the ICON observations,near the equator,zonal winds reverse from westward to eastward at around 06:00 local time(LT)at higher altitudes,and the stronger westward winds appear at later LTs at lower altitudes.At around 16:00 LT,eastward winds at 300 km reverse to westward,and vertical gradients of zonal winds similar to those at sunrise hours can be observed.In the middle latitudes,zonal winds reverse about 2-4 h earlier.Meridional winds vary more significantly than zonal winds with seasonal and latitudinal variations.According to the ICON observations,in the northern low latitudes,vertical reversals of meridional winds are found at 08:00-13:00 LT from 300 to 160 km and at around 18:00 LT from 300 to 200 km during the June solstice.Similar reversals of meridional winds are found at 04:00-07:00 LT from 300 to 160 km and at 22:00-02:00 LT from 270 to 200 km during the December solstice.In the southern low latitudes,meridional wind reversals occur at 08:00-11:00 LT from 200 to 160 km and at 21:00-02:00 LT from 300 to 200 km during the June solstice.During the December solstice,reversals of the meridional wind appear at 20:00-01:00 LT below 200 km and at 06:00-11:00 LT from 300 to 160 km.In the northern middle latitudes,the northward winds are dominant at 08:00-14:00 LT at 230 km during the June solstice.Northward winds persist until 16:00 LT at 160 and 300 km.During the December solstice,the northward winds are dominant from 06:00 to 21:00 LT.The vertical variations in neutral winds during the geomagnetic storm on August 26-28 were analyzed in detail.Both meridional and zonal winds during the active geomagnetic period observed by ICON show distinguishable vertical shear structures at different stages of the storm.On the dayside,during the main phase,the peak velocities of westward winds extend from a higher altitude to a lower altitude,whereas during the recovery phase,the peak velocities of the westward winds extend from lower altitudes to higher altitudes.The velocities of the southward winds are stronger at lower altitudes during the storm.These vertical structures of horizontal winds during the storm could not be reproduced by the HWM14 wind estimations,and the overall response to the storm of the horizontal winds in the low and middle latitudes is underestimated by HWM14.The ICON observations provide a good dataset for improving the HWM wind estimations in the middle and upper atmosphere,especially the vertical variations.
基金support from China National Natural Science Foundation (11672333)。
文摘The effectiveness of horizontal well multi-stage and multi-cluster fracturing in the fractured soft coal seam roof for coalbed methane(CBM) extraction has been demonstrated.This study focuses on the geological characteristics of the No.5 and No.11 coal seams in the Hancheng Block,Ordos Basin,China.A multi-functional,variable-size rock sample mold capable of securing the wellbore was developed to simulate layered formations comprising strata of varying lithology and thicknesses.A novel segmented fracturing simulation method based on an expandable pipe plugging technique is proposed.Large-scale true triaxial experiments were conducted to investigate the effects of horizontal wellbore location,perforation strategy,roof lithology,and vertical stress difference on fracture propagation,hydraulic energy variation,and the stimulated reservoir volume in horizontal wells targeting the soft coal seam roof.The results indicate that bilateral downward perforation with a phase angle of 120° optimizes hydraulic energy conservation,reduces operational costs,enhances fracture formation,and prevents fracturing failure caused by coal powder generation and migration.This perforation mode is thus considered optimal for coal seam roof fracturing.When the roof consists of sandstone,each perforation cluster tends to initiate a single dominant fracture with a regular geometry.In contrast,hydraulic fractures formed in mudstone roofs display diverse morphology.Due to its high strength,the sandstone roof requires significantly higher pressure for crack initiation and propagation,whereas the mudstone roof,with its strong water sensitivity,exhibits lower fracturing pressures.To mitigate inter-cluster interference,cluster spacing in mudstone roofs should be greater than that in sandstone roofs.Horizontal wellbore placement critically influences fracturing effectiveness.For indirect fracturing in sandstone roofs,an optimal position is 25 mm away from the lithological interface.In contrast,the optimal location for indirect fracturing in mudstone roofs is directly at the lithological interface with the coal seam.Higher vertical stress coefficients lead to increased fractu ring pressures and promote vertical,layer-penetrating fractures.A coefficient of 0.5 is identified as optimal for achieving effective indirect fracturing.This study provides valuable insights for the design and optimization of staged fracturing in horizontal wells targeting crushed soft coal seam roofs.
基金supported by the National Natural Science Foundation of China(52274055)the Shandong Provincial Natural Science Foundation(ZR2022YQ50)the Taishan Scholar Program of Shandong Province(tsqn202408088)。
文摘Predicting the productivity of multistage fractured horizontal wells plays an important role in exploiting unconventional resources.In recent years,machine learning(ML)models have emerged as a new approach for such studies.However,the scarcity of sufficient real data for model training often leads to imprecise predictions,even though the models trained with real data better characterize geological and engineering features.To tackle this issue,we propose an ML model that can obtain reliable results even with a small amount of data samples.Our model integrates the synthetic minority oversampling technique(SMOTE)to expand the data volume,the support vector machine(SVM)for model training,and the particle swarm optimization(PSO)algorithm for optimizing hyperparameters.To enhance the model performance,we conduct feature fusion and dimensionality reduction.Additionally,we examine the influences of different sample sizes and ML models for training.The proposed model demonstrates higher prediction accuracy and generalization ability,achieving a predicted R^(2)value of up to 0.9 for the test set,compared to the traditional ML techniques with an R^(2)of 0.13.This model accurately predicts the production of fractured horizontal wells even with limited samples,supplying an efficient tool for optimizing the production of unconventional resources.Importantly,the model holds the potential applicability to address similar challenges in other fields constrained by scarce data samples.
基金supported by the National Natural Science Foundation of China(Grant number 42201302)the"Double First-Class"University Construction Project of Lanzhou University(Grant number:561120213)。
文摘The horizontal ecological compensation plays an important role in balancing the interests of all parties and coordinating regional development in the basin.However,the mechanism of ecological compensation based on embodied carbon emissions is still poorly understood.Here,taking the Yellow River Basin as the research area,we use the multi-regional input-output(MRIO)model to measure the embodied carbon transfers between its seven urban agglomerations in 2012 and 2017 from the viewpoint of value-added trade benefits.Further,for the first time,the green trade benefits and ecological compensation amounts are analyzed.The results indicate that:(1)The transfer of trade-embodied carbon among the urban agglomerations in the basin showed obvious spatial heterogeneity and geographic proximity effects,and trade-embodied carbon outflows(inflows)had a pattern of"highest in the midstream,second in the downstream,and lowest in the upstream".(2)The industry composition of the urban agglomerations in relation to embodied carbon outflows(inflows)was similar,mainly in the service and heavy manufacturing industries.(3)The spatial pattern of green trade benefits in the basin had shifted from"high in the north and low in the surrounding area"to"high in the east-central part and low in the west".(4)The pattern of ecological compensation in the basin had shifted from the upstream surplus,the middle and downstream deficit to the midstream deficit,and the upstream and downstream surplus.Therefore,we recommend improving energy structures in high-demand urban agglomerations by adopting clean energy,focusing on decarbonization and energy efficiency in resource-rich regions.Additionally,promoting low-carbon economies,especially in the service and heavy manufacturing industries,implementing differentiated emission reduction strategies,and optimizing carbon compensation mechanisms considering regional disparities and resource endowments are crucial.It is expected that the study can enrich the scientific basis of horizontal ecological compensation and increase the fairness of regional carbon emission rights allocation.
基金supported by National Key Research and Development Program of China,China(2024YFD1800102,2022YFD1800105 and 2022YFD1801500)National Natural Science Foundation of China,China(32372993 and 32030107)Fundamental Research Funds for the Central Universities,China(2662023PY005).
文摘Zika virus(ZIKV)is a mosquito-borne virus belonging to the genus Orthoflavivirus,and the family Flaviviridae.It commonly presents with febrile-like symptoms,neurological issues,and pregnancy complications in humans.Currently,there is no commercial vaccine or specific treatment available to prevent ZIKV infection.Therefore,controlling the epidemic's spread relies on preventing mosquitoes from transmitting the virus.Although various studies have explored the transmission of ZIKV between mosquitoes and vertebrate hosts,comprehensive research on potential mosquito-to-mosquito transmission of ZIKV remains limited.In this study,we conducted systematic laboratory investigations to assess the ability of ZIKV to spread among mosquitoes,and to evaluate the impact of ZIKV infection on mosquito development.Our findings revealed that ZIKV can be transmitted between Aedes aegypti mosquitoes both vertically and horizontally,through oviposition and contact between mosquitoes of the same or opposite sex.Additionally,we observed that ZIKV infection resulted in a reduction in the number of mosquito eggs but an increase in their size.The widespread distribution of ZIKV in infected mosquitoes and the altered levels of hormone related genes following viral infection were noted,which may contribute to viral transmission among mosquitoes and affect mosquito development.This research provides systematic experimental evidence of ZIKV transmission among mosquitoes,which is crucial for developing novel strategies to disrupt the spread of orthoflaviviruses and other mosquitoborne pathogens.
基金financially supported by the National Natural Science Foundation of China(No.52204084)the Open Research Fund of the State Key Laboratory of Coal Resources and safe Mining,CUMT,China(No.SKLCRSM 23KF004)+3 种基金the Interdisciplinary Research Project for Young Teachers of USTB(Fundamental Research Funds for the Central Universities),China(No.FRF-IDRY-GD22-002)the Fundamental Research Funds for the Central Universities and the Youth Teacher International Exchange and Growth Program,China(No.QNXM20220009)the National Key R&D Program of China(Nos.2022YFC2905600 and 2022 YFC3004601)the Science,Technology&Innovation Project of Xiongan New Area,China(No.2023XAGG0061)。
文摘Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress magnitude.To investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution method.The results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with depth.There is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and messy.Moreover,there is no obvious relationship between the rock quality designation(RQD)and depth.The maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same depth.In addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data.
基金supported by Jiangsu Agriculture Science and Technology Innovation Fund(No.CX(22)3001)。
文摘The escalating global dissemination of plasmid-mediated antibiotic resistance poses a formidable threat to global health.Conjugation stands as a pivotal mechanism for horizontal gene transfer among bacterial populations,facilitating the spread of antibiotic resistance genes(ARGs).Microelectrolysis has garnered attention as an efficacious strategy for mitigating antibiotic concentrations in wastewater,yet its potential impact on ARG horizontal transfer remain largely unexplored.This comprehensive investigation unveils that microelectrolysis not only influences but significantly accelerates the conjugative transfer of ARG-harboring plasmids.Remarkably,this phenomenon is corroborated at the microbial community scale,underscoring its ecological relevance.Alarmingly,the study highlights the vulnerability of intestinalmicroorganisms to acquire antibiotic resistance under electrolytic stimulation,posing heightened risks to both animal and human health.Delving deeper,the study elucidates the underlyingmechanisms responsible for this enhanced conjugative transfer.It reveals that microelectrolysis augments the abundance of mating-competent cells,triggers the generation of reactive oxygen species,inflicts modest membrane damage,and upregulates the expression of genes critical for conjugation.These findings collectively contribute to a more profound comprehension of the environmental dissemination dynamics and associated public health implications of ARGs in the context of wastewater treatment employing microelectrolytic technologies.
基金funded by the Ministry of Education of the Russian Federation within the framework of a state assignment,number 1023032300071-6-2.3.1.
文摘Time-averaged thermal convection in a rotating horizontal annulus with a higher temperature at its inner boundary is studied.The centrifugal force plays a stabilizing role,while thermal convection is determined by the“thermovibrational mechanism”.Convective flow is excited due to oscillations of a non-isothermal rotating fluid.Thermal vibrational convectionmanifests in the form of two-dimensional vortices elongated along the axis of rotation,which develop in a threshold manner with an increase in the amplitude of fluid oscillations.The objective of the present study is to clarify the nature of another phenomenon,i.e.,three-dimensional convective vortices observed in the experiments both before the excitation of the convection described above and in the supercritical region.The experimental study of the oscillatory and the time-averaged flow fields by particle image velocimetry is accompanied by the theoretical research of inertial waves.It is found that three-dimensional fluid flows owe their origin to inertial waves.This is confirmed by a high degree of agreement between the experimental and theoretical results.Experiments with cavities of different lengths indicate that the vortices are clearly seen in cavities thatmeet the conditions of resonant excitation of inertial modes.Furthermore,the length of the cavity has no effect on heat transfer,which is explained by the comparatively low intensity of the wave-induced flows.The main contribution to heat transfer is due to vortices elongated along the axis of rotation.The novel results are of significant practical importance in various fields.
文摘The China Spallation Neutron Source(CSNS)is the fourth pulsed accelerator-driven neutron source in the world,and it achieved its design target of 100 kW in 2020.The planned China Spallation Neutron Source Phase II(CSNS-II)commenced in 2024.The CSNS-II linac design primarily involves the addition of a radio-frequency ion source and a section of a superconducting linear accelerator composed of two types of superconducting cavities,namely double-spoke and six-cell elliptical cavities,after the drift tube linac(DTL).The development of the double-spoke superconducting cavity began in early 2021,and by January 2023,the welding,post-processing,and vertical tests of two 324 MHz double-spoke cavity prototypes were completed,with vertical test gradients of 11.6 and 15 MV/m,and Q_(0)≥3×10^(10)@E_(acc)≤10 MV/m.The R&D of the cryomodule began in January 2022.In October 2023,the clean assembly of the double-spoke cavity string and cold mass installation of the cryomodule commenced,with the installation of the cryomodule and valve box completing in two months.In January 2024,a horizontal test of the cryomodule was completed,making it the first double-spoke cavity cryomodule in China.The test results showed that the maximum gradients of the two superconducting cavities at a pulse width of 4 ms and repetition frequency of 25 Hz were 12.8 and 15.2 MV/m,respectively.This article provides a detailed introduction to the double-spoke superconducting cavity,tuner,coupler,and cryomodule,elaborates on the clean assembly of the cavity string and cold mass installation of the cryomodule,and provides a detailed analysis of the horizontal test results.
基金supported by the National Natural Science Foundation of China(Nos.42177124 and 41877277)Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences(No.SKLGME022011)+2 种基金Fundamental Research Funds for the Central Universities(No.2024KYJD1011)Frontier Technologies R&D Program of Jiangsu(No.BF2024056)the Graduate Innovation Program of China University of Mining and Technology(No.KYCX25_3085)。
文摘Salt deposits in China predominantly originate from lake deposits,characterized by thin salt beds interspersed with numerous interlayers,collectively termed bedded salt formations.Historically,the solution mining practices have adopted the layered solution mining approach,inspired by coal mining techniques.However,this approach fails to account for the unique challenges of salt solution mining.Practical implementation is inefficient,costs escalate post-construction,and cavern geometry is constrained by salt beds thickness.Additionally,resource loss in abandoned beds and stability risks in adjacent mining zones remain unresolved.This study investigates mining scheme selection for low-grade salt deposits in Huai'an Salt Basin,introducing a continuous solution mining method that traverses multiple interlayers.Through comprehensive analysis of plastic deformation in caverns and surrounding rock,volume shrinkage rates,and economic costs comparing continuous and layered solution mining approaches,the results demonstrate that:(1)In the layered solution mining with horizontal interconnected wells scheme,plastic deformation zones propagate unevenly,posing interlayer connectivity risks.Concurrently,roof subsidence and floor heave destabilize the structure;(2)the continuous solution mining with horizontal interconnected wells scheme reduces plastic deformation zones to 3.4%of cavern volume,with volumetric shrinkage below 17%,markedly improving stability;(3)Economically,the continuous solution mining scheme generates caverns 2.43 times larger than the layered solution mining,slashing unit volume costs to 41.1%while enhancing resource recovery and long-term viability.The continuous method demonstrates distinct economic advantages and achieves higher resource utilization efficiency in solution mining compared to layered mining.Furthermore,its superior cavern stability presents strong potential for large-scale implementation.
基金financially supported by the National Key Research and Development Plan(2023YFC2811001)the National Natural Science Foundation of China(42206233)the Taishan Scholars Program(tsqn202312280,tsqn202306297)。
文摘Hydraulic fracturing technology has played an important role in the exploitation of unconventional oil and gas resources,however,its application to gas hydrate reservoirs has been rarely studied.Currently,there is still limited understanding of the propagation and extension of fractures around the wellbore during the fracturing process of horizontal wells in hydrate reservoirs,as well as the stress interference patterns between fractures.This study simulates hydraulic fracturing processes in hydrate reservoirs using a fluidsolid coupling discrete element method(DEM),and analyzes the impacts of hydrate saturation and geological and engineering factors on fracture extension and stress disturbance.The results show that hydraulic fracturing is more effective when hydrate saturation exceeds 30%and that fracture pressure increases with saturation.The increase in horizontal stress differential enhances the directionality of fracture propagation and reduces stress disturbance.The distribution uniformity index(DUI)reveals that injection pressure is directly proportional to the number of main fractures and inversely proportional to fracturing time,with fracturing efficiency depending on the spacing between injection points and the distance between wells.This work may provide reference for the commercial exploitation of natural gas hydrates.
文摘To explore and evaluate the longitudinal utilization degree of marine shale gas horizontal wells in southern Sichuan Basin(hereinafter referred to as“southern Sichuan”),focusing on the shale of Wufeng formation-Longyi1 sub-member in the deep Z block.By using the data from core experiments,well logging,and fracture height detection,a systematic analysis from the perspectives of reservoir distribution,longitudinal utilization height of hydraulic fractures,and longitudinal utilization degree of horizontal wells was conducted.The research results show that:(1)The overall reservoir conditions of theWufeng formation-Longyi1 sub-member in the study area are relatively favorable,although the quality of Type Ⅰ reservoir varies significantly among different well blocks;(2)The proppant tracer fracture height detection results show that fractures tend to extend upwards,the average total fracture height of fracture extend is 12.7 m,with the average upward extension height is 2.5 times the downward extension height;(3)The combination of fracture height and gas well productivity analysis suggests that targeting sub-layer 1 as the horizontal well target can achieve full production of the continuous thickness of Type Ⅰ reservoir in Z2 well block,whereas in Z1 well block,due to the significant proportion of the Wufeng formation in the continuous thickness of Type Ⅰ reservoir,in the areas where the continuous thickness of Type Ⅰ reservoir in Wufeng formation to middle sub-layer 1 is greater than 4 m,horizontal wells cannot achieve full longitudinal utilization of the continuous thickness in top-quality Type Ⅰ reservoir.The conclusion is that due to the limitations of longitudinal utilization height by artificial fracture networks and the variability in the distribution of continuous thickness of Type Ⅰ reservoir,Z1 well block can continue to conduct horizontal well target tests and differentiated fracturing designs to further enhance the longitudinal utilization degree of the top-quality Type Ⅰ reservoir.
基金Supported by the National Key Research and Development Program of China(2023YFF0615403)CNPC Science and Technology Project(2023ZZ0803).
文摘A flexible sidetracking stimulation technology of horizontal wells is formed to develop the lateral deep remaining oil and gas resources of the low-permeability mature oilfields.This technology first uses the flexible sidetracking tool to achieve low-cost sidetracking in the old wellbore,and then uses the hydraulic jet technology to induce multiple fractures to fracture.Finally,the bullhead fracturing of multi-cluster temporary plugging for the sidetracking hole is carried out by running the tubing string,to realize the efficient development of the remaining reserves among the wells.The flexible sidetracking stimulation technology involves flexible sidetracking horizontal wells drilling and sidetracking horizontal well fracturing.The flexible sidetracking horizontal well drilling includes three aspects:flexible drill pipe structure and material optimization,drilling technology,and sealed coring tool.The sidetracking horizontal well fracturing includes two aspects:fracturing scheme optimization,fracturing tools and implementation process optimization.The technology has been conducted several rounds of field tests in the Ansai Oilfield of Changqing,China.The results show that by changing well type and reducing row spacing of oil and water wells,the pressure displacement system can be well established to achieve effective pressure transmission and to achieve the purpose of increasing liquid production in low-yield and low-efficiency wells.It is verified that the flexible sidetracking stimulation technology can provide favorable support for accurately developing remaining reserves in low-permeability reservoirs.
文摘As an important part of offshore wind turbine support and fixed units, the multibucket jacket foundation bears large loads and a complex marine environment. In this paper, the horizontal bearing characteristics of the four-bucket jacket foundation of offshore wind power in sandy soil are studied. Through model tests and numerical simulations, the influence of bucket foundation sealing properties, load application speed, and loading direction on foundation-bearing capacity are discussed. The results show that the horizontal ultimate bearing capacity of the foundation in the nonsealing condition is decreased by 51.3% compared with the sealing condition;therefore, after the foundation penetration construction is completed, the bucket sealing must be ensured to increase the load-bearing performance of the structure. At a loading speed of 3.25 mm/s, the horizontal ultimate bearing capacity of the foundation is increased by 9.4% over the working condition of 1.85 mm/s. The bearing capacity of the foundation is maximized in the loading direction α =45° and is the smallest when α =0°. That is, the foundation can maximize its loadbearing performance under the condition of single-bucket compression/tension. During the design process, the main load of the structure should be loaded in the 45° direction. The contrast error of the experiment and numerical simulation does not exceed 10%. The research results have important guiding importance for designing and constructing the jacket foundation and can be used as a reference for the stable operation and sustainable development of offshore wind power systems.
基金supported by the National Natural Science Foundation of China(Grant No.U2142201)the Fengyun Application Pion eering Project(Grant No.FY-APP-ZX-2022.01)。
文摘Measurements from a hyperspectral infrared(HIR) sounder onboard a satellite in geostationary orbit not only provide atmospheric thermodynamic information,but also can be used to infer dynamic information with high temporal resolution.Radiance measurements from the Geostationary Interferometric Infrared Sounder(GIIRS),obtained with 15-min temporal resolution during Typhoon Maria(2018) and 30-min temporal resolution during Typhoon Lekima(2019),were used to derive three-dimensional(3D) horizontal winds by tracking the motion of atmospheric moisture.This work focused on the impact of assimilation of 3D winds on typhoon analyses and forecasts using the operational NWP model of the China Meteorological Administration(CMA-MESO),and improved understanding of the potential benefits of assimilating dynamic information from geostationary sounder data with higher temporal resolution.The standard deviation of the observations minus simulations revealed that the accuracy of the derived 3D winds with 15-min resolution was higher than that of derived winds with 30-min resolution.Experiments showed that the assimilation system can effectively absorb the information of the derived 3D winds,and that dynamic information from clear-sky areas can be transferred to typhoon areas.In typhoon prediction,assimilation of the derived 3D winds had greatest influence on the typhoon track,and less influence on the maximum wind speed.Assimilation of the derived 3D winds reduced the average track error by 17.4% for Typhoon Maria(2018) and by 3.5% for Typhoon Lekima(2019) during their entire 36-h forecasts initiated at different times.Assimilation of GIIRS dynamic information can substantially improve forecasts of heavy precipitation by CMAMESO.Results indicate that the assimilation of dynamic information from high-temporal-resolution geostationary HIR sounder data adds value for improved numerical weather prediction.
基金supported in part by the National Natural Science Foundation of China under Grant U2441250 and 62231027in part by Natural Science Basic Research Programof Shaanxi under Grant 2024JC-JCQN-63+2 种基金in part by InnovationCapability Support Program of Shaanxi under Grant2024RS-CXTD-01in part by New Technology Research University Cooperation Project under Grant SKX242010031in part by the FundamentalResearch Funds for the Central Universities and theInnovation Fund of Xidian University under GrantYJSJ25007.
文摘With the widespread application of com-munication technology in the non-terrestrial network(NTN),the issue of the insecure communication due to the inherent openness of the NTN is increasingly being recognized.Consequently,safeguarding com-munication information in the NTN has emerged as a critical challenge.To address this issue,we pro-pose a beamforming and horizontal trajectory joint op-timization method for unmanned aerial vehicle(UAV)covert communications in the NTN.First,we formu-late an optimization problem that considers constraints such as the transmitting power and the distance.More-over,we employ the integrated communication and jamming(ICAJ)signal as Alice’s transmitting signal,further protecting the content of communication in-formation.Next,we construct two subproblems,and we propose an alternate optimization(AO)algorithm based on quadratic transform and penalty term method to solve the proposed two subproblems.Simulation re-sults demonstrate that the proposed method is effective and has better performance than benchmarks.
基金supported by the National Natural Science Foundation of China under Grant No.62271040,and 62341102the Fundamental Research Funds for the Central Universities under Grant No.2023JBGP004.
文摘In the rapidly evolving landscape of Industry 4.0(I4.0),the convergence of information and operational technologies necessitates real-time communication and collaboration across cyber-physical systems and the Internet of Things(IoT).Rapid data transmission is particularly critical within enterprises(vertically)and among stakeholders(horizontally)in this complex,heterogeneous ecosystem.While current research has focused on data application,processing,and storage within the cloud-edge-device continuum,cross-edge transmission has received less attention,resulting in challenges such as suboptimal routing and excessive delays in horizontal communications.To address the above issues,this paper introduces a Connection-As-Required Scheme(CARS)specifically designed for delay-sensitive IoT and Cyber-Physical System(CPS)applications,where low-latency communication is essential for operational efficiency.CARS leverages Lyapunov optimization and backpressure algorithms to optimize traffic scheduling and routing,minimizing communication delay between entities.Benchmarking against state-of-the-art solutions,CARS reduces Round-Trip Time(RTT)to approximately 47.0%of conventional methods and decreases delay by 24.5%in TCP-based and 26.0%in UDP-based applications.These results highlight the potential of CARS to facilitate effective,low-latency collaboration in diverse I4.0 environments.
