With the rapid advancements in technology and science,optimization theory and algorithms have become increasingly important.A wide range of real-world problems is classified as optimization challenges,and meta-heurist...With the rapid advancements in technology and science,optimization theory and algorithms have become increasingly important.A wide range of real-world problems is classified as optimization challenges,and meta-heuristic algorithms have shown remarkable effectiveness in solving these challenges across diverse domains,such as machine learning,process control,and engineering design,showcasing their capability to address complex optimization problems.The Stochastic Fractal Search(SFS)algorithm is one of the most popular meta-heuristic optimization methods inspired by the fractal growth patterns of natural materials.Since its introduction by Hamid Salimi in 2015,SFS has garnered significant attention from researchers and has been applied to diverse optimization problems acrossmultiple disciplines.Its popularity can be attributed to several factors,including its simplicity,practical computational efficiency,ease of implementation,rapid convergence,high effectiveness,and ability to address singleandmulti-objective optimization problems,often outperforming other established algorithms.This review paper offers a comprehensive and detailed analysis of the SFS algorithm,covering its standard version,modifications,hybridization,and multi-objective implementations.The paper also examines several SFS applications across diverse domains,including power and energy systems,image processing,machine learning,wireless sensor networks,environmental modeling,economics and finance,and numerous engineering challenges.Furthermore,the paper critically evaluates the SFS algorithm’s performance,benchmarking its effectiveness against recently published meta-heuristic algorithms.In conclusion,the review highlights key findings and suggests potential directions for future developments and modifications of the SFS algorithm.展开更多
Considering the three typical phase-change related rock mechanics phenomena during drilling and production in oil and gas reservoirs,which include phase change of solid alkane-related mixtures upon heating,sand liquef...Considering the three typical phase-change related rock mechanics phenomena during drilling and production in oil and gas reservoirs,which include phase change of solid alkane-related mixtures upon heating,sand liquefaction induced by sudden pressure release of the over-pressured sand body,and formation collapse due to gasification of pore fillings from pressure reduction,this study first systematically analyzes the progress of theoretical understanding,experimental methods,and mathematical representation,then discusses the engineering application scenarios corresponding to the three phenomena and reveals the mechanical principles and application effectiveness.Based on these research efforts,the study further discusses the significant challenges,potential developmental trends,and research approaches that require urgent exploration.The findings disclose that various phase-related rock mechanics phenomena require specific experimental and mathematical methods that can produce multi-field coupling mechanical mechanisms,which will eventually instruct the control on resource exploitation,evaluation on disaster level,and analysis of formation stability.To meet the development needs of the principle,future research efforts should focus on mining more phase-change related rock mechanics phenomena during oil and gas resources exploitation,developing novel experimental equipment,and using techniques of artificial intelligence and digital twins to implement real-time simulation and dynamic visualization of phase-change related rock mechanics.展开更多
To ameliorate the difficulties of on-site dynamic disaster control in the end-mining stage of traditional mining engineering,this paper introduces the mathematical research and engineering application of the end-minin...To ameliorate the difficulties of on-site dynamic disaster control in the end-mining stage of traditional mining engineering,this paper introduces the mathematical research and engineering application of the end-mining technology system with non-pillar in mines(ETSNM)in recent years.The petal warning criterion for the stability of the surrounding rock of the roadway at the end-mining stage was obtained by studying the inverse problem of the petal theorem.A conformal mathematical model of the end-mining stage was established using the conformal mapping method,and the limit theorem of the peak point of mine pressure(LTPPMP)in the end-mining stage was demonstrated.Based on the cross-fusion of the above basic mathematical theory and the LTPPMP,a new ETSNM model was proposed,which includes no coal pillar,no dedicated retracement roadways,and fast retracement equipment(NNF).The mathematical principles of engineering technology for height control,speed limit,and roof cutting in the end-mining stage with non-pillar were revealed.The scientific and application values of the ETSNM were confirmed through engineering applications.Based on this,a new non-pillar control technology for dynamic disasters in the end-mining stage was proposed.The above research will play an active role in promoting the engineering application of ETSNM driven by mathematical theory.展开更多
Existing creep constitutive models rarely incorporate studies on the coupling mechanism between creep damage and rock strain softening/hardening.This study analyzed the strain softening and hardening behaviors of argi...Existing creep constitutive models rarely incorporate studies on the coupling mechanism between creep damage and rock strain softening/hardening.This study analyzed the strain softening and hardening behaviors of argillaceous sandstone and sandy mudstone during load-induced failure based on the plastic increment theory.These behaviors were then coupled with an improved Burgers creep model to establish a coupled creep-damage and plastic softening/hardening model.Finally,the validity and engineering applicability of the proposed model were verified through FLAC~(3D)numerical simulations.The numerical simulation results of standard cylindrical specimens show that the established coupling model can effectively reflect the unloading creep deformation law and failure characteristics of argillaceous sandstone and sandy mudstone.Taking the diversion tunnel of a hydropower station in Northwest China as an example for engineering application,the coupled creep-damage and plastic softening/hardening model is introduced into FLAC~(3D)to carry out numerical simulation calculation of the tunnel under excavation and unsupported creep conditions.The results show that the uncoordinated deformation of the upper and lower walls of the surrounding rock of the tunnel is more prominent.When the buried depth of the tunnel increases to 80 m,the monitoring point C in the sandy mudstone area of the upper wall shows nonlinear accelerated deformation under unsupported creep conditions,and the maximum displacement in the horizontal direction reaches 44.5 mm,and the maximum displacement in the vertical direction reaches 53.5 mm.The coupled creep-damage and plastic softening/hardening model established in the research results can well describe the whole process of uncoordinated deformation and failure in the unloading creep process of soft-hard interbedded rock mass.展开更多
In this review,the development and application of microbially induced carbonate precipitation(MICP)technology for the sealing of underground engineering fractures are discussed in detail.The importance of sealing micr...In this review,the development and application of microbially induced carbonate precipitation(MICP)technology for the sealing of underground engineering fractures are discussed in detail.The importance of sealing micro-fractures in an environmentally friendly and efficient manner is emphasized,and the potential of the MICP method in controlling pore and fracture seepage is highlighted.The fundamental mechanisms,key influencing factors,numerical models,and applications of the MICP in the fields of geological CO_(2) storage and oil resources development are comprehensively summarized in the paper.At the same time,the limitations of the existing research and the future research directions are discussed,especially in terms of improving the processing efficiency,environmental impacts,and cost considerations.Overall,the development of MICP technology provides a new environmentally friendly reinforcement method for geotechnical engineering and is expected to play a key role in the future development of underground space engineering.展开更多
A new one-parameter Chris-Jerry distribution,created by mixing exponential and gamma distributions,is discussed in this article in the presence of incomplete lifetime data.We examine a novel generalized progressively ...A new one-parameter Chris-Jerry distribution,created by mixing exponential and gamma distributions,is discussed in this article in the presence of incomplete lifetime data.We examine a novel generalized progressively hybrid censoring technique that ensures the experiment ends at a predefined period when the model of the test participants has a Chris-Jerry(CJ)distribution.When the indicated censored data is present,Bayes and likelihood estimations are used to explore the CJ parameter and reliability indices,including the hazard rate and reliability functions.We acquire the estimated asymptotic and credible confidence intervals of each unknown quantity.Additionally,via the squared-error loss,the Bayes’estimators are obtained using gamma prior.The Bayes estimators cannot be expressed theoretically since the likelihood density is created in a complex manner;nonetheless,Markov-chain Monte Carlo techniques can be used to evaluate them.The effectiveness of the investigated estimations is assessed,and some recommendations are given using Monte Carlo results.Ultimately,an analysis of two engineering applications,such as mechanical equipment and ball bearing data sets,shows the applicability of the proposed approaches that may be used in real-world settings.展开更多
In the multi-radar networking system,aiming at the problem of locating long-distance targets synergistically with difficulty and low accuracy,a dual-station joint positioning method based on the target measurement err...In the multi-radar networking system,aiming at the problem of locating long-distance targets synergistically with difficulty and low accuracy,a dual-station joint positioning method based on the target measurement error feature complementarity is proposed.For dual-station joint positioning,by constructing the target positioning error distribution model and using the complementarity of spatial measurement errors of the same long-distance target,the area with high probability of target existence can be obtained.Then,based on the target distance information,the midpoint of the intersection between the target positioning sphere and the positioning tangent plane can be solved to acquire the target's optimal positioning result.The simulation demonstrates that this method greatly improves the positioning accuracy of target in azimuth direction.Compared with the traditional the dynamic weighted fusion(DWF)algorithm and the filter-based dynamic weighted fusion(FBDWF)algorithm,it not only effectively eliminates the influence of systematic error in the azimuth direction,but also has low computational complexity.Furthermore,for the application scenarios of multi-radar collaborative positioning and multi-sensor data compression filtering in centralized information fusion,it is recommended that using radar with higher ranging accuracy and the lengths of baseline between radars are 20–100 km.展开更多
Sticky rice is not only a notoriously food, or a kind of important medicinal herb, but also serves as a kind of important engineering materials having rich re- sources. Sticky rice has excellent toughness, anti-seepag...Sticky rice is not only a notoriously food, or a kind of important medicinal herb, but also serves as a kind of important engineering materials having rich re- sources. Sticky rice has excellent toughness, anti-seepage property, bonding proper- ty, reinforcing property, high strength and superior engineering performance with su- perior engineering value, ecolOgical value and landscape value on account of its starch composition mainly composed of amylopectin of which the granules are poly- hedron. The development and application of sticky rice has important strategic signif- icance to promotion of sustainable development of ecological landscape construction, alleviation of resource shortage, reduction of environmental pollution, acceleration of constructing environmental friendly society and realization of sustainable development of China.展开更多
1. Introduction High-speed gas-particle flows are crucial in engineering applications and natural phenomena, such as volcanic eruptions,combustion, and hypersonic flight. These flows involve complex gas-particle inter...1. Introduction High-speed gas-particle flows are crucial in engineering applications and natural phenomena, such as volcanic eruptions,combustion, and hypersonic flight. These flows involve complex gas-particle interactions, posing significant challenges for simulations and experiments. This research highlight summarizes recent advancements in gas-particle dynamics under compressible conditions, covering key findings, numerical and experimental progress, and future directions. Details can be found in the work of Capecelatro and Wagner (Gas-particle dynamics in high-speed flows. Annual Review of Fluid Mechanics 2024;56:379–403).展开更多
Three-dimensional(3 D)printing has revolutionized the design and production of customized scaffolds,but the minimally invasive implantation of 3 D-printed structures into the human body remains challenging.This has pr...Three-dimensional(3 D)printing has revolutionized the design and production of customized scaffolds,but the minimally invasive implantation of 3 D-printed structures into the human body remains challenging.This has prompted the exploration of innovative materials and technical solutions.Shape-memory polymers,as advanced intelligent materials,exhibit considerable potential in minimally invasive surgical applications.Herein,we developed a novel thermosetting shape-memory polymer,poly(L-lactic acid)-trimethylene carbonate-glycolic acid(PLLA-TMC-GA),for the fabrication of bioengineered scaffolds with body temperature-activated shape-memory functionality.We comprehensively evaluated the mechanical properties,thermal stability,shape-memory capabilities,biocompatibility,biodegradability,and 3 D printing performance of PLLA-TMC-GA terpolymers with various compositions.The results indicate that PLLA-TMC-GA exhibits exceptional shape-memory performance,adjustable material properties,favorable biocompatibility,and the potential for controlled biodegradation and reabsorption.The use of PLLA-TMC-GA as a biodegradable shape-memory polymer allows the reduction of implant volume,simplifies implantation,and enables on-demand activation at body temperature.These characteristics present new opportunities for the advancement of minimally invasive surgical techniques.展开更多
The disorderly mining activities and irrational layout in underground coal mines have left a large number of adjacent abandoned roadways.During the process of a working face passing through abandoned roadways,these st...The disorderly mining activities and irrational layout in underground coal mines have left a large number of adjacent abandoned roadways.During the process of a working face passing through abandoned roadways,these structures are prone to varying degrees of damage,with frequent occurrences of roof leakage and induced rock burst accidents,significantly impacting subsequent mining operations and safe production.To address these issues,this study investigates the surrounding rock deformation patterns during fully mechanized mining face passage through abandoned roadway clusters.Specific countermeasures were systematically summarized according to different occurrence characteristics of abandoned roadways.Through mechanical analysis,the critical unstable width of coal pillars was determined to be approximately 16.1~16.8 m.A three-dimensional numerical model was established based on 17 abandoned roadways with various shapes and occurrences in the working face.Simulation results indicate severe deformation and failure in roof rock layer roadways,while floor roadways exhibit relatively minor damage.Notably,when the distance between abandoned roadways and the coal seam exceeds 8 m,almost no damage occurs.Three technical measures for passing through abandoned roadway group was proposed according to their occurrence characteristics and implemented in engineering practice.Field applications demonstrate limited coal stress variations and weak strata pressure manifestations during the crossing process,ensuring safe passage through abandoned roadway clusters.This achievement enables efficient and safe crossing of abandoned roadway group in fully mechanized mining faces,enhances coal recovery rates,and provides practical engineering references for similar geological conditions.展开更多
The rock mass rating(RMR)system is one of the most commonly used methods for classifying rock masses in underground engineering.Uncertainty of RMR values can signifi cantly aff ect the safety of underground projects.I...The rock mass rating(RMR)system is one of the most commonly used methods for classifying rock masses in underground engineering.Uncertainty of RMR values can signifi cantly aff ect the safety of underground projects.In this regard,we proposed a reliable rating approach for classifying rock masses based on the reliability theory.This theory was incorporated into the RMR system to establish the functions of rock masses of different classifications.By analyzing the probability distribution patterns of various parameters used in the RMR system and using the Monte Carlo method to calculate the reliability probability of surrounding rock belonging to each classifi cation,reliable RMR values for the rock mass to be excavated can be obtained.The results demonstrate that it is feasible to adopt the reliability theory in classifi cation tasks considering the randomness characteristics of rock and soil.As verified through a case study of the Lushan Tunnel project,the proposed approach can be used to obtain the probability of the uncertainty of the calculated RMR values of underground engineering rock masses,and the calculation results are consistent with reality.The proposed approach can serve as a reference for studies in other fi elds and also applies to other rock mass classifi cation methods.展开更多
To fundamentally alleviate the excavation chamber clogging during slurry tunnel boring machine(TBM)advancing in hard rock,large-diameter short screw conveyor was adopted to slurry TBM of Qingdao Jiaozhou Bay Second Un...To fundamentally alleviate the excavation chamber clogging during slurry tunnel boring machine(TBM)advancing in hard rock,large-diameter short screw conveyor was adopted to slurry TBM of Qingdao Jiaozhou Bay Second Undersea Tunnel.To evaluate the discharging performance of short screw conveyor in different cases,the full-scale transient slurry-rock two-phase model for a short screw conveyor actively discharging rocks was established using computational fluid dynamics-discrete element method(CFD-DEM)coupling approach.In the fluid domain of coupling model,the sliding mesh technology was utilized to describe the rotations of the atmospheric composite cutterhead and the short screw conveyor.In the particle domain of coupling model,the dynamic particle factories were established to produce rock particles with the rotation of the cutterhead.And the accuracy and reliability of the CFD-DEM simulation results were validated via the field test and model test.Furthermore,a comprehensive parameter analysis was conducted to examine the effects of TBM operating parameters,the geometric design of screw conveyor and the size of rocks on the discharging performance of short screw conveyor.Accordingly,a reasonable rotational speed of screw conveyor was suggested and applied to Jiaozhou Bay Second Undersea Tunnel project.The findings in this paper could provide valuable references for addressing the excavation chamber clogging during ultra-large-diameter slurry TBM tunneling in hard rock for similar future.展开更多
Founded in 1993,Zhejiang Rifa Textile Machinery Co.,Ltd.is a national key high-tech enterprise,a leading enterprise in China’s machinery industry,a CIMS engineering demonstration enterprise under the 863 Program,a na...Founded in 1993,Zhejiang Rifa Textile Machinery Co.,Ltd.is a national key high-tech enterprise,a leading enterprise in China’s machinery industry,a CIMS engineering demonstration enterprise under the 863 Program,a national CAD application engineering demonstration enterprise,a hightech enterprise of the National Torch Plan,and a vice president unit of the China Textile Machinery Association.It currently runs three subsidiaries,namely,Shandong Rifa Textile Machinery Co.,Ltd.,Anhui Rifa Textile Machinery Co.,Ltd.and Zhejiang Rifa Textile Machinery Tech Co.,Ltd.展开更多
Plasma Science and Technology(PST)journal assists in advancing plasma science and technology by reporting important,novel,helpful and thought-provoking progress in this strongly multidisciplinary and interdisciplinary...Plasma Science and Technology(PST)journal assists in advancing plasma science and technology by reporting important,novel,helpful and thought-provoking progress in this strongly multidisciplinary and interdisciplinary field,in a timely manner.This field encompasses foundational plasma phenomena;low-temperature plasmas;magnetically confined plasmas;inertially confined plasmas;astrophysics and space plasmas;and interdisciplinary science of these;and the engineering and technology development and application from them.展开更多
Plasma Science and Technology(PST)journal assists in advancing plasma science and technology by reporting important,novel,helpful and thought-provoking progress in this strongly multidisciplinary and interdis ciplinar...Plasma Science and Technology(PST)journal assists in advancing plasma science and technology by reporting important,novel,helpful and thought-provoking progress in this strongly multidisciplinary and interdis ciplinary field,in a timely manner.This field encompasses foundational plasma phenomena;low-temperature plasmas;magnetically confined plasmas;inertially confined plasmas;astrophysics and space plasmas;and interdisciplinary science of these;and the engineering and technology development and application from them.PST is sponsored jointly by the Institute of Plasma Physics of the Chinese Academy of Sciences,and the Chinese Society of Theoretical and Applied Mechanics.The journal joined the Scienc e Citation Index in 2003,the Engineering Index in 2006,and became published online by IOP Publishing Ltd.in 2006.展开更多
Plasma Science and Technology(PST)journal assists in advancing plasma science and technology by reporting important,novel,helpful and thought-provoking progress in this strongly multidisciplinary and interdisciplinary...Plasma Science and Technology(PST)journal assists in advancing plasma science and technology by reporting important,novel,helpful and thought-provoking progress in this strongly multidisciplinary and interdisciplinary field,in a timely manner.This field encompasses foundational plasma phenomena;low-temperature plasmas;magnetically confined plasmas;inertially confined plasmas;astrophysics and space plasmas;and interdisciplinary science of these;and the engineering and technology development and application from them.展开更多
The traditional stability analysis method of geogrid reinforced slopes does not consider the effect of lateral swelling,so it is not applicable to reinforced expansive soil slopes.This paper reports a new stability an...The traditional stability analysis method of geogrid reinforced slopes does not consider the effect of lateral swelling,so it is not applicable to reinforced expansive soil slopes.This paper reports a new stability analysis method for geogrid reinforced expansive soil slopes.The additional pullout force of the free zone due to the lateral swelling and the anti-pullout safety factor of each geogrid layer were obtained by ensuring the overall stability of the reinforced slope.The optimum design was carried out to treat an expansive soil cut slope in Hubei Province,China,by changing the spacing and length of geogrid reinforcement.Calculation results show that the additional pullout force caused by lateral swelling has a great influence on the anti-pullout stability of geogrids,and the local stability of the reinforced slope will be overestimated if the swelling effect of soil in the free zone is not considered.展开更多
The industrial application prospect and key issues in basic theory and application are discussed by the methods of theoretical analysis and calculation to promote the development of the pure-hydrogen reduction process...The industrial application prospect and key issues in basic theory and application are discussed by the methods of theoretical analysis and calculation to promote the development of the pure-hydrogen reduction process.According to the discussion of thermodynamics and kinetics of pure-hydrogen reduction reaction,the reduction reaction of iron oxide by pure hydrogen is an endothermic reaction,and the reaction rate of hydrogen reduction is significantly faster than that of carbon reduction.To explore the feasibility of the industrial applications of pure-hydrogen reduction,we design the hydrogen reduction reactor and process with reference to the industrialized hydrogen-rich reduction process and put forward the methods of appropriately increasing the reduction temperature,pressure,and temperature of iron ore into the furnace to accelerate the reaction rate and promote the reduction of iron oxide.The key technical parameters in engineering applications,such as hydrogen consumption,circulating gas volume,and heat balance,are discussed by theoretical calculations,and the optimized parameter values are proposed.The process parameters,cost,advantages,and disadvantages of various current hydrogen production methods are compared,and the results show that hydrogen production by natural gas reforming has a good development prospect.Through the discussion of the corrosion mechanism of high-temperature and high-pressure hydrogen on heat-resistant steel materials and the corrosion mechanism of H_2S in the hydrogen gas on steel,the technical ideas of developing new metal temperature-resistant materials,metal coating materials,and controlling gas composition are put forward to provide guidance for the selection of heater and reactor materials.Finally,the key factors affecting the smooth operation of the hydrogen reduction process in engineering applications are analyzed,offering a reference for the industrial application of the purehydrogen reduction process.展开更多
With the increase in mining depth, the danger of coal and gas outbursts increases.In order to drain coal gas effectively and to eliminate the risk of coal and gas outbursts, we used a specific number of penetration bo...With the increase in mining depth, the danger of coal and gas outbursts increases.In order to drain coal gas effectively and to eliminate the risk of coal and gas outbursts, we used a specific number of penetration boreholes for draining of pressure relief gas.Based on the principle of overlying strata movement, deformation and pressure relief, a good effect of gas drainage was obtained.The practice in the Panyi coal mine has shown that, after mining the C11coal seam as the protective layer, the relative expansion deformation value of the protected layer C13 reached 2.63%, The permeability coefficient increased 2880 times, the gas drainage rate of the C13 coal seam increased to more than 60%, the amount of gas was reduced from 13.0 to 5.2 m3/t and the gas pressure declined from 4.4 to 0.4 MPa, which caused the danger the outbursts in the coal seams to be eliminated.The result was that we achieved a safe and highly efficient mining operation of the C13 coal seam.展开更多
基金supported by Prince Sattam bin Abdulaziz University for funding this research work through the project number(2024/RV/06).
文摘With the rapid advancements in technology and science,optimization theory and algorithms have become increasingly important.A wide range of real-world problems is classified as optimization challenges,and meta-heuristic algorithms have shown remarkable effectiveness in solving these challenges across diverse domains,such as machine learning,process control,and engineering design,showcasing their capability to address complex optimization problems.The Stochastic Fractal Search(SFS)algorithm is one of the most popular meta-heuristic optimization methods inspired by the fractal growth patterns of natural materials.Since its introduction by Hamid Salimi in 2015,SFS has garnered significant attention from researchers and has been applied to diverse optimization problems acrossmultiple disciplines.Its popularity can be attributed to several factors,including its simplicity,practical computational efficiency,ease of implementation,rapid convergence,high effectiveness,and ability to address singleandmulti-objective optimization problems,often outperforming other established algorithms.This review paper offers a comprehensive and detailed analysis of the SFS algorithm,covering its standard version,modifications,hybridization,and multi-objective implementations.The paper also examines several SFS applications across diverse domains,including power and energy systems,image processing,machine learning,wireless sensor networks,environmental modeling,economics and finance,and numerous engineering challenges.Furthermore,the paper critically evaluates the SFS algorithm’s performance,benchmarking its effectiveness against recently published meta-heuristic algorithms.In conclusion,the review highlights key findings and suggests potential directions for future developments and modifications of the SFS algorithm.
基金Supported by the National Natural Science Foundation of China(NSFC)Major Project(51991362).
文摘Considering the three typical phase-change related rock mechanics phenomena during drilling and production in oil and gas reservoirs,which include phase change of solid alkane-related mixtures upon heating,sand liquefaction induced by sudden pressure release of the over-pressured sand body,and formation collapse due to gasification of pore fillings from pressure reduction,this study first systematically analyzes the progress of theoretical understanding,experimental methods,and mathematical representation,then discusses the engineering application scenarios corresponding to the three phenomena and reveals the mechanical principles and application effectiveness.Based on these research efforts,the study further discusses the significant challenges,potential developmental trends,and research approaches that require urgent exploration.The findings disclose that various phase-related rock mechanics phenomena require specific experimental and mathematical methods that can produce multi-field coupling mechanical mechanisms,which will eventually instruct the control on resource exploitation,evaluation on disaster level,and analysis of formation stability.To meet the development needs of the principle,future research efforts should focus on mining more phase-change related rock mechanics phenomena during oil and gas resources exploitation,developing novel experimental equipment,and using techniques of artificial intelligence and digital twins to implement real-time simulation and dynamic visualization of phase-change related rock mechanics.
基金supported by the National Natural Science Foundation of China(No.12071047,51774289,52074291).
文摘To ameliorate the difficulties of on-site dynamic disaster control in the end-mining stage of traditional mining engineering,this paper introduces the mathematical research and engineering application of the end-mining technology system with non-pillar in mines(ETSNM)in recent years.The petal warning criterion for the stability of the surrounding rock of the roadway at the end-mining stage was obtained by studying the inverse problem of the petal theorem.A conformal mathematical model of the end-mining stage was established using the conformal mapping method,and the limit theorem of the peak point of mine pressure(LTPPMP)in the end-mining stage was demonstrated.Based on the cross-fusion of the above basic mathematical theory and the LTPPMP,a new ETSNM model was proposed,which includes no coal pillar,no dedicated retracement roadways,and fast retracement equipment(NNF).The mathematical principles of engineering technology for height control,speed limit,and roof cutting in the end-mining stage with non-pillar were revealed.The scientific and application values of the ETSNM were confirmed through engineering applications.Based on this,a new non-pillar control technology for dynamic disasters in the end-mining stage was proposed.The above research will play an active role in promoting the engineering application of ETSNM driven by mathematical theory.
基金funded by the Natural Science Foundation of China(Grant No.U22A20600)。
文摘Existing creep constitutive models rarely incorporate studies on the coupling mechanism between creep damage and rock strain softening/hardening.This study analyzed the strain softening and hardening behaviors of argillaceous sandstone and sandy mudstone during load-induced failure based on the plastic increment theory.These behaviors were then coupled with an improved Burgers creep model to establish a coupled creep-damage and plastic softening/hardening model.Finally,the validity and engineering applicability of the proposed model were verified through FLAC~(3D)numerical simulations.The numerical simulation results of standard cylindrical specimens show that the established coupling model can effectively reflect the unloading creep deformation law and failure characteristics of argillaceous sandstone and sandy mudstone.Taking the diversion tunnel of a hydropower station in Northwest China as an example for engineering application,the coupled creep-damage and plastic softening/hardening model is introduced into FLAC~(3D)to carry out numerical simulation calculation of the tunnel under excavation and unsupported creep conditions.The results show that the uncoordinated deformation of the upper and lower walls of the surrounding rock of the tunnel is more prominent.When the buried depth of the tunnel increases to 80 m,the monitoring point C in the sandy mudstone area of the upper wall shows nonlinear accelerated deformation under unsupported creep conditions,and the maximum displacement in the horizontal direction reaches 44.5 mm,and the maximum displacement in the vertical direction reaches 53.5 mm.The coupled creep-damage and plastic softening/hardening model established in the research results can well describe the whole process of uncoordinated deformation and failure in the unloading creep process of soft-hard interbedded rock mass.
基金support provided by the National Natural Science Foundation of China(No.42177141).
文摘In this review,the development and application of microbially induced carbonate precipitation(MICP)technology for the sealing of underground engineering fractures are discussed in detail.The importance of sealing micro-fractures in an environmentally friendly and efficient manner is emphasized,and the potential of the MICP method in controlling pore and fracture seepage is highlighted.The fundamental mechanisms,key influencing factors,numerical models,and applications of the MICP in the fields of geological CO_(2) storage and oil resources development are comprehensively summarized in the paper.At the same time,the limitations of the existing research and the future research directions are discussed,especially in terms of improving the processing efficiency,environmental impacts,and cost considerations.Overall,the development of MICP technology provides a new environmentally friendly reinforcement method for geotechnical engineering and is expected to play a key role in the future development of underground space engineering.
基金This research was funded by Princess Nourah bint Abdulrahman University Researchers Supporting Project Number(PNURSP2024R50)Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia.
文摘A new one-parameter Chris-Jerry distribution,created by mixing exponential and gamma distributions,is discussed in this article in the presence of incomplete lifetime data.We examine a novel generalized progressively hybrid censoring technique that ensures the experiment ends at a predefined period when the model of the test participants has a Chris-Jerry(CJ)distribution.When the indicated censored data is present,Bayes and likelihood estimations are used to explore the CJ parameter and reliability indices,including the hazard rate and reliability functions.We acquire the estimated asymptotic and credible confidence intervals of each unknown quantity.Additionally,via the squared-error loss,the Bayes’estimators are obtained using gamma prior.The Bayes estimators cannot be expressed theoretically since the likelihood density is created in a complex manner;nonetheless,Markov-chain Monte Carlo techniques can be used to evaluate them.The effectiveness of the investigated estimations is assessed,and some recommendations are given using Monte Carlo results.Ultimately,an analysis of two engineering applications,such as mechanical equipment and ball bearing data sets,shows the applicability of the proposed approaches that may be used in real-world settings.
文摘In the multi-radar networking system,aiming at the problem of locating long-distance targets synergistically with difficulty and low accuracy,a dual-station joint positioning method based on the target measurement error feature complementarity is proposed.For dual-station joint positioning,by constructing the target positioning error distribution model and using the complementarity of spatial measurement errors of the same long-distance target,the area with high probability of target existence can be obtained.Then,based on the target distance information,the midpoint of the intersection between the target positioning sphere and the positioning tangent plane can be solved to acquire the target's optimal positioning result.The simulation demonstrates that this method greatly improves the positioning accuracy of target in azimuth direction.Compared with the traditional the dynamic weighted fusion(DWF)algorithm and the filter-based dynamic weighted fusion(FBDWF)algorithm,it not only effectively eliminates the influence of systematic error in the azimuth direction,but also has low computational complexity.Furthermore,for the application scenarios of multi-radar collaborative positioning and multi-sensor data compression filtering in centralized information fusion,it is recommended that using radar with higher ranging accuracy and the lengths of baseline between radars are 20–100 km.
基金Supported by Science and Technology Planning Project of Hunan Province(2011NK3046)Hunan Leading Academic Discipline Project of Botany during the Twelfth Five-year~~
文摘Sticky rice is not only a notoriously food, or a kind of important medicinal herb, but also serves as a kind of important engineering materials having rich re- sources. Sticky rice has excellent toughness, anti-seepage property, bonding proper- ty, reinforcing property, high strength and superior engineering performance with su- perior engineering value, ecolOgical value and landscape value on account of its starch composition mainly composed of amylopectin of which the granules are poly- hedron. The development and application of sticky rice has important strategic signif- icance to promotion of sustainable development of ecological landscape construction, alleviation of resource shortage, reduction of environmental pollution, acceleration of constructing environmental friendly society and realization of sustainable development of China.
文摘1. Introduction High-speed gas-particle flows are crucial in engineering applications and natural phenomena, such as volcanic eruptions,combustion, and hypersonic flight. These flows involve complex gas-particle interactions, posing significant challenges for simulations and experiments. This research highlight summarizes recent advancements in gas-particle dynamics under compressible conditions, covering key findings, numerical and experimental progress, and future directions. Details can be found in the work of Capecelatro and Wagner (Gas-particle dynamics in high-speed flows. Annual Review of Fluid Mechanics 2024;56:379–403).
基金supported by the National Natural Science Foundation of China(Nos.82402822,82360427,82372425,82072443,and 32200559)the Priority Union Foundation of Yunnan Provincial Science and Technology Department and Kunming Medical University(No.202301AY070001-164)+1 种基金the Natural Science Foundation of Sichuan Province(No.23NSFSC5880)the Central Government of Sichuan Province Guiding the Special Project of Local Science and Technology Development(No.2024ZYD0155).
文摘Three-dimensional(3 D)printing has revolutionized the design and production of customized scaffolds,but the minimally invasive implantation of 3 D-printed structures into the human body remains challenging.This has prompted the exploration of innovative materials and technical solutions.Shape-memory polymers,as advanced intelligent materials,exhibit considerable potential in minimally invasive surgical applications.Herein,we developed a novel thermosetting shape-memory polymer,poly(L-lactic acid)-trimethylene carbonate-glycolic acid(PLLA-TMC-GA),for the fabrication of bioengineered scaffolds with body temperature-activated shape-memory functionality.We comprehensively evaluated the mechanical properties,thermal stability,shape-memory capabilities,biocompatibility,biodegradability,and 3 D printing performance of PLLA-TMC-GA terpolymers with various compositions.The results indicate that PLLA-TMC-GA exhibits exceptional shape-memory performance,adjustable material properties,favorable biocompatibility,and the potential for controlled biodegradation and reabsorption.The use of PLLA-TMC-GA as a biodegradable shape-memory polymer allows the reduction of implant volume,simplifies implantation,and enables on-demand activation at body temperature.These characteristics present new opportunities for the advancement of minimally invasive surgical techniques.
基金supported by the National Key R&D Program of China(2023YFC3904300)the Taichuangyuan Thick Coal Seam Water Conservation Mining"Scientists+Engineers"Team(2024QCY-KXJ-055)the 111 Project(B21016).
文摘The disorderly mining activities and irrational layout in underground coal mines have left a large number of adjacent abandoned roadways.During the process of a working face passing through abandoned roadways,these structures are prone to varying degrees of damage,with frequent occurrences of roof leakage and induced rock burst accidents,significantly impacting subsequent mining operations and safe production.To address these issues,this study investigates the surrounding rock deformation patterns during fully mechanized mining face passage through abandoned roadway clusters.Specific countermeasures were systematically summarized according to different occurrence characteristics of abandoned roadways.Through mechanical analysis,the critical unstable width of coal pillars was determined to be approximately 16.1~16.8 m.A three-dimensional numerical model was established based on 17 abandoned roadways with various shapes and occurrences in the working face.Simulation results indicate severe deformation and failure in roof rock layer roadways,while floor roadways exhibit relatively minor damage.Notably,when the distance between abandoned roadways and the coal seam exceeds 8 m,almost no damage occurs.Three technical measures for passing through abandoned roadway group was proposed according to their occurrence characteristics and implemented in engineering practice.Field applications demonstrate limited coal stress variations and weak strata pressure manifestations during the crossing process,ensuring safe passage through abandoned roadway clusters.This achievement enables efficient and safe crossing of abandoned roadway group in fully mechanized mining faces,enhances coal recovery rates,and provides practical engineering references for similar geological conditions.
基金supported by the National Natural Science Foundation of China [Grant No.52079077]China Postdoctoral Science Foundation (Grant No. 2022M711962)。
文摘The rock mass rating(RMR)system is one of the most commonly used methods for classifying rock masses in underground engineering.Uncertainty of RMR values can signifi cantly aff ect the safety of underground projects.In this regard,we proposed a reliable rating approach for classifying rock masses based on the reliability theory.This theory was incorporated into the RMR system to establish the functions of rock masses of different classifications.By analyzing the probability distribution patterns of various parameters used in the RMR system and using the Monte Carlo method to calculate the reliability probability of surrounding rock belonging to each classifi cation,reliable RMR values for the rock mass to be excavated can be obtained.The results demonstrate that it is feasible to adopt the reliability theory in classifi cation tasks considering the randomness characteristics of rock and soil.As verified through a case study of the Lushan Tunnel project,the proposed approach can be used to obtain the probability of the uncertainty of the calculated RMR values of underground engineering rock masses,and the calculation results are consistent with reality.The proposed approach can serve as a reference for studies in other fi elds and also applies to other rock mass classifi cation methods.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2023YJS053)the National Natural Science Foundation of China(Grant No.52278386).
文摘To fundamentally alleviate the excavation chamber clogging during slurry tunnel boring machine(TBM)advancing in hard rock,large-diameter short screw conveyor was adopted to slurry TBM of Qingdao Jiaozhou Bay Second Undersea Tunnel.To evaluate the discharging performance of short screw conveyor in different cases,the full-scale transient slurry-rock two-phase model for a short screw conveyor actively discharging rocks was established using computational fluid dynamics-discrete element method(CFD-DEM)coupling approach.In the fluid domain of coupling model,the sliding mesh technology was utilized to describe the rotations of the atmospheric composite cutterhead and the short screw conveyor.In the particle domain of coupling model,the dynamic particle factories were established to produce rock particles with the rotation of the cutterhead.And the accuracy and reliability of the CFD-DEM simulation results were validated via the field test and model test.Furthermore,a comprehensive parameter analysis was conducted to examine the effects of TBM operating parameters,the geometric design of screw conveyor and the size of rocks on the discharging performance of short screw conveyor.Accordingly,a reasonable rotational speed of screw conveyor was suggested and applied to Jiaozhou Bay Second Undersea Tunnel project.The findings in this paper could provide valuable references for addressing the excavation chamber clogging during ultra-large-diameter slurry TBM tunneling in hard rock for similar future.
文摘Founded in 1993,Zhejiang Rifa Textile Machinery Co.,Ltd.is a national key high-tech enterprise,a leading enterprise in China’s machinery industry,a CIMS engineering demonstration enterprise under the 863 Program,a national CAD application engineering demonstration enterprise,a hightech enterprise of the National Torch Plan,and a vice president unit of the China Textile Machinery Association.It currently runs three subsidiaries,namely,Shandong Rifa Textile Machinery Co.,Ltd.,Anhui Rifa Textile Machinery Co.,Ltd.and Zhejiang Rifa Textile Machinery Tech Co.,Ltd.
文摘Plasma Science and Technology(PST)journal assists in advancing plasma science and technology by reporting important,novel,helpful and thought-provoking progress in this strongly multidisciplinary and interdisciplinary field,in a timely manner.This field encompasses foundational plasma phenomena;low-temperature plasmas;magnetically confined plasmas;inertially confined plasmas;astrophysics and space plasmas;and interdisciplinary science of these;and the engineering and technology development and application from them.
文摘Plasma Science and Technology(PST)journal assists in advancing plasma science and technology by reporting important,novel,helpful and thought-provoking progress in this strongly multidisciplinary and interdis ciplinary field,in a timely manner.This field encompasses foundational plasma phenomena;low-temperature plasmas;magnetically confined plasmas;inertially confined plasmas;astrophysics and space plasmas;and interdisciplinary science of these;and the engineering and technology development and application from them.PST is sponsored jointly by the Institute of Plasma Physics of the Chinese Academy of Sciences,and the Chinese Society of Theoretical and Applied Mechanics.The journal joined the Scienc e Citation Index in 2003,the Engineering Index in 2006,and became published online by IOP Publishing Ltd.in 2006.
文摘Plasma Science and Technology(PST)journal assists in advancing plasma science and technology by reporting important,novel,helpful and thought-provoking progress in this strongly multidisciplinary and interdisciplinary field,in a timely manner.This field encompasses foundational plasma phenomena;low-temperature plasmas;magnetically confined plasmas;inertially confined plasmas;astrophysics and space plasmas;and interdisciplinary science of these;and the engineering and technology development and application from them.
基金Project(51978085)supported by the National Natural Science Foundation of ChinaProject(201808430102)supported by the China Scholarship Council+1 种基金Project(JTG-201507)supported by the Highway Industry Standard Compilation Project of Ministry of Transportation,ChinaProject(kfj180102)supported by the Open Fund of Changsha University of Science&Technology,China。
文摘The traditional stability analysis method of geogrid reinforced slopes does not consider the effect of lateral swelling,so it is not applicable to reinforced expansive soil slopes.This paper reports a new stability analysis method for geogrid reinforced expansive soil slopes.The additional pullout force of the free zone due to the lateral swelling and the anti-pullout safety factor of each geogrid layer were obtained by ensuring the overall stability of the reinforced slope.The optimum design was carried out to treat an expansive soil cut slope in Hubei Province,China,by changing the spacing and length of geogrid reinforcement.Calculation results show that the additional pullout force caused by lateral swelling has a great influence on the anti-pullout stability of geogrids,and the local stability of the reinforced slope will be overestimated if the swelling effect of soil in the free zone is not considered.
基金financially supported by the National Natural Science Foundation of China(No.52104297)the National Key R&D Plan(No.2019YFC1905202)。
文摘The industrial application prospect and key issues in basic theory and application are discussed by the methods of theoretical analysis and calculation to promote the development of the pure-hydrogen reduction process.According to the discussion of thermodynamics and kinetics of pure-hydrogen reduction reaction,the reduction reaction of iron oxide by pure hydrogen is an endothermic reaction,and the reaction rate of hydrogen reduction is significantly faster than that of carbon reduction.To explore the feasibility of the industrial applications of pure-hydrogen reduction,we design the hydrogen reduction reactor and process with reference to the industrialized hydrogen-rich reduction process and put forward the methods of appropriately increasing the reduction temperature,pressure,and temperature of iron ore into the furnace to accelerate the reaction rate and promote the reduction of iron oxide.The key technical parameters in engineering applications,such as hydrogen consumption,circulating gas volume,and heat balance,are discussed by theoretical calculations,and the optimized parameter values are proposed.The process parameters,cost,advantages,and disadvantages of various current hydrogen production methods are compared,and the results show that hydrogen production by natural gas reforming has a good development prospect.Through the discussion of the corrosion mechanism of high-temperature and high-pressure hydrogen on heat-resistant steel materials and the corrosion mechanism of H_2S in the hydrogen gas on steel,the technical ideas of developing new metal temperature-resistant materials,metal coating materials,and controlling gas composition are put forward to provide guidance for the selection of heater and reactor materials.Finally,the key factors affecting the smooth operation of the hydrogen reduction process in engineering applications are analyzed,offering a reference for the industrial application of the purehydrogen reduction process.
基金Projects 2005CB221503 supported by the National Basic Research Program of China70533050 and 50674089 by the National Natural Science Foundationof China
文摘With the increase in mining depth, the danger of coal and gas outbursts increases.In order to drain coal gas effectively and to eliminate the risk of coal and gas outbursts, we used a specific number of penetration boreholes for draining of pressure relief gas.Based on the principle of overlying strata movement, deformation and pressure relief, a good effect of gas drainage was obtained.The practice in the Panyi coal mine has shown that, after mining the C11coal seam as the protective layer, the relative expansion deformation value of the protected layer C13 reached 2.63%, The permeability coefficient increased 2880 times, the gas drainage rate of the C13 coal seam increased to more than 60%, the amount of gas was reduced from 13.0 to 5.2 m3/t and the gas pressure declined from 4.4 to 0.4 MPa, which caused the danger the outbursts in the coal seams to be eliminated.The result was that we achieved a safe and highly efficient mining operation of the C13 coal seam.
