The effect of coix seed flour(0%–25%)on the rheological and structural properties of wheat dough and noodle quality was investigated.The addition of coix seed flour was found to enhance the elasticity of dough,which ...The effect of coix seed flour(0%–25%)on the rheological and structural properties of wheat dough and noodle quality was investigated.The addition of coix seed flour was found to enhance the elasticity of dough,which may be attributed to the fact that small starch particles increase the filling capacity within the dough matrix.This increase subsequently resulted in more complete and uniform structure of dough.Moreover,setback viscosity rose to 1095 cP.The rapid water absorption of coix seed starch led to changes in the secondary structure of proteins in dough.The proportion ofβ-sheet markedly increased,whereas the proportion ofα-helix decreased with increasing level of coix seed flour substitution.Meanwhile,coix seed flour substitution significantly reduced the estimated glycemic index of noodles.Correlation analysis revealed that pasting parameters had significant effects on the evaluation of noodle quality.This study provides a foundation for researchers to substitute wheat flour with coix seed flour.展开更多
【Background】The application of beneficial-microbial seed soaking prior to sowing represents a novel technology that has not been employed in Lanzhou lily cultivation.We conducted an experiment to explore the impact ...【Background】The application of beneficial-microbial seed soaking prior to sowing represents a novel technology that has not been employed in Lanzhou lily cultivation.We conducted an experiment to explore the impact of this soaking method on the fungal and bacterial community structures using next-generation sequencing technology(NGS).【Methods】Lily bulbs were soaked in a seed treating agent containing beneficial microbes(SP treatment)for 4 hours.Subsequently,they were planted in soil in July and sampled in September to assess plant growth,rhizosphere soil physicochemical properties,and microorganism community structures.In addition,we employed the software PICRUSt and FUNGuild to predict bacterial pathways and fungal functions.【Results】Under SP treatment,there were significant alterations in fungi and bacteria community structures,accompanied by improved soil nutrient status.Notably,the relative abundance of dominant microorganism groups,such as the fungi Basidiomycota,Pseudeurotium,Cladophialophora,Microascus,and Dactylonectria,as well as the bacteria Proteobacteria,Chloroflexi,Ochrobactrium,Lysobacter,and RB41,underwent notable changes.Microorganism function prediction results indicated a reduction in pathotrophic fungi(including plant pathogens)and an increase in endophytic and saprotrophic fungi under SP treatment.Among the top 20 metabolism pathways,80%were upregulated in SP treatment compared to the CK.【Conclusions】Seed soaking with beneficial microbial strain promotes the growth of Lanzhou lily bulbs.The beneficial microorganisms play a crucial role in regulating soil microbial structures,enhancing the accumulation of endophytic fungi,reducing the abundance of pathogens,and improving soil functions.Furthermore,specific microbial groups are found to be involved in maintaining soil health.展开更多
Cotton,a crucial commercial fibre crop,depends heavily on seed-associated characteristics like germination rate,vigour,and resistance to post-harvest deterioration for both production and lint quality.Serious cellular...Cotton,a crucial commercial fibre crop,depends heavily on seed-associated characteristics like germination rate,vigour,and resistance to post-harvest deterioration for both production and lint quality.Serious cellular damage dur-ing post-harvest processes such as delinting,prolonged seedling emergence periods,decreased viability,increased susceptibility to infections,and lipid peroxidation during storage pose serious problems to seed quality.The perfor-mance of seeds and total crop productivity are adversely affected by these problems.Traditional methods of seed improvement,like physical scarification and seed priming,have demonstrated promise in raising cotton seed vigour and germination rates.Furthermore,modern approaches including plasma therapies,magnetic water treatments,and nanotechnology-based treatments have shown promise in improving seed quality and reducing environmen-tal stresses.By offering sustainable substitutes for conventional approaches,these cutting-edge procedures lessen the need for fungicides and other agrochemicals that pollute the environment.This review explores various con-ventional and emerging strategies to address the detrimental factors impacting cotton seed quality.It emphasizes the importance of integrating classical and advanced approaches to enhance germination,ensure robust crop estab-lishment,and achieve higher yields.In addition to promoting sustainable cotton production,this kind of integration helps preserve the ecosystem and create resilient farming methods.展开更多
Cemented tailings backfill(CTB)is a crucial support material for ensuring the long-term stability of underground goafs.A comprehensive understanding of its compressive mechanical behavior is essential for improving en...Cemented tailings backfill(CTB)is a crucial support material for ensuring the long-term stability of underground goafs.A comprehensive understanding of its compressive mechanical behavior is essential for improving engineering safety.Although extensive studies have been conducted on the uniaxial compressive properties of CTB,damage constitutive models that effectively capture its damage evolution process remain underdeveloped,and its failure mechanisms are not yet fully clarified.To address these gaps,this study conducted systematic uniaxial compression tests on CTB specimens prepared with varying cement-tailings ratios.The results revealed distinct compaction and softening phases in the stress−strain curves.A lower cement-tailings ratio significantly reduced the strength and deformation resistance of CTB,along with a decrease in elastic energy accumulation at peak stress and dissipation energy in the post peak stage.Based on these findings,a modified damage constitutive model was developed by introducing a correction factor,enabling accurate simulation of the entire uniaxial compression process of CTB with different cement-tailings ratios.Comparative analysis with classical constitutive models validated the proposed model’s accuracy and applicability in describing the compressive behavior of CTB.Furthermore,particle size distribution and acoustic emission tests were employed to investigate the influence of cement-tailings ratio on failure mechanisms.The results indicated that a lower cement-tailings ratio leads to coarser particle sizes,which intensify shear-related acoustic emission signals and ultimately result in more pronounced macroscopic shear failure.This study provides theoretical support and practical guidance for the optimal design of CTB mix ratios.展开更多
This study designs four types of liquid-filled cylindrical shell structures to investigate their protection characteristics against explosive shock waves and high-speed fragments.Bare charge and charge-driven prefabri...This study designs four types of liquid-filled cylindrical shell structures to investigate their protection characteristics against explosive shock waves and high-speed fragments.Bare charge and charge-driven prefabricated fragments are employed to examine the damage under blast shock waves and combined blast and fragments loading on various liquid-filled cylindrical shell structures.The test results are compared to numerical calculations and theoretical analysis for the structure's deformation,the liquid medium's movement,and the pressure waves'propagation characteristics under different liquid-filling methods.The results showed that the filling method influences the blast protection and the struc-ture's energy absorption performance.The external filling method reduces the structural deformation,and the internal filling method increases the damage effect.The gapped internal filling method improves the structure's energy absorption efficiency.The pressure wave loading on the liquid-filled cylindrical shell structure differs depending on filling methods.Explosive shock waves and high-speed fragments show a damage enhancement effect on the liquid-filled cylindrical shell structure,depending on the thickness of the internal liquid container layer.The specific impulse on the inner surface of the cylindrical shell positively correlates to the radial deformation of the cylindrical shell structure,and the external liquid layer limits the radial structural deformation.展开更多
Longhole caving method was used to mine gently inclined thick orebody step by step in a test stope of tin mine under complex filling body. The problem that the complex filling body around the stope affects the stabili...Longhole caving method was used to mine gently inclined thick orebody step by step in a test stope of tin mine under complex filling body. The problem that the complex filling body around the stope affects the stability of roof thickness, chamber and spacer pillar in actual mining was investigated; meanwhile, the formed goaf during mining is so vulnerable that surrounding rock collapses early. Based on this point, elasticity mechanics and limit span theory were used to study separately the roof thickness and the span limit of goaf formed in mining, and then a reasonable roof thickness of 8 m and goaf span of 14 m are proposed. In addition, the stability of roof thickness, chamber and spacer pillar were investigated and analyzed by using numerical analysis method; meanwhile, the field monitoring on the displacement of caving chamber was conducted. The results show that the maximum compressive stress of surrounding rock is 20 MPa, and the maximum tensile stress is 1.2 MPa, which is less than the ultimate tensile strength of 2.4 MPa. Moreover, plastic zone has little influence on stope stability. In addition, the displacement of 11 mm is also smaller. The displacement monitoring results are consistent with the numerical results. Thus, the roof thickness and span of goaf proposed are safe.展开更多
It is the basic requirement of the synergetic exploitation of deep mineral resources and geothermal resources to arrange the heat transfer tube in filling body. The heat release performance of filling body directly im...It is the basic requirement of the synergetic exploitation of deep mineral resources and geothermal resources to arrange the heat transfer tube in filling body. The heat release performance of filling body directly impacts on the exploiting efficiency of geothermal energy. Based on heat transfer theory, a three-dimensional unsteady heat transfer model of filling body is established by using FLUENT simulation software. Taking the horizontal U-shaped buried pipe as research object, the variation of temperature field in filling body around buried pipe is analyzed during the heat release process of filling body;the initial temperature of filling body, the diameter of buried pipe, the inlet temperature and inlet velocity of heat transfer fluid influencing of coupling heat transfer, which exists between heat transfer fluid and surrounding filling body within a certain axial distance of buried tube, and influencing of temperature difference between inlet and outlet of heat transfer fluid and on heat transfer performance of filling body are also discussed. It not only lays a theoretical foundation for the synergetic exploitation of mineral resources and geothermal energy in deep mines, but also provides a reference basis for the arrangement of buried pipes in filling body as well as the selection of working conditions for heat transfer fluid.展开更多
The treatment of contaminated soil is a crucial issue in geotechnical and environmental engineering.This study proposes to incorporate appropriate polypropylene fibers and cements as an effective method to treat heavy...The treatment of contaminated soil is a crucial issue in geotechnical and environmental engineering.This study proposes to incorporate appropriate polypropylene fibers and cements as an effective method to treat heavy metal contaminated soil(HMCS).The objective of this paper is to investigate the effects of fiber content,fiber length,cement content,curing time,heavy metal types and concentration on the mechanical properties of soils.To this end,a series of direct shear test,unconfined compression strength(UCS)test,dry-wet cycle and freeze-thaw cycle test are performed.The results confirm that the appropriate reinforcement of polypropylene fibers and cement is an effective way to recycle HMCS as substitutable fillers in roadbed,which exhibits benefits in environment and economy development.展开更多
In the South Yellow Sea Basin,Mesozoic–Paleozoic marine strata are generally well developed with large thickness,and no substantial breakthroughs have been made in hydrocarbon exploration.Through research,it is belie...In the South Yellow Sea Basin,Mesozoic–Paleozoic marine strata are generally well developed with large thickness,and no substantial breakthroughs have been made in hydrocarbon exploration.Through research,it is believed that the Upper Permian–Lower Triassic can be regarded as a long-term base-level cycle.Based on drilling data,characteristics of the lithology–electric property combination cyclicity,and the special lithology,the long-term base-level cycle was divided into five medium-term base-level cycles(MC1–MC5).On this basis,the Permian–Triassic sedimentary systems and their filling model were analyzed in accordance with the change of base-level cycle and transition of sedimentary environment,as well as characteristics of the drilling sedimentary facies and seismic facies.The results show that there were six sedimentary systems(fluvial,delta,tidal flat,open platform,restricted platform,and continental shelf)developed in the Upper Permian–Lower Triassic,the sedimentary systems were distributed such that the water was deep in the northwest and shallow in the southeast,and there were two base-level cycle filling models(a relatively stable tidal flat facies and a rapidly transgressive continental shelf facies to stable platform facies)developed in the Upper Permian–Lower Triassic.These models can provide a basis for evaluation of the Mesozoic–Paleozoic hydrocarbon geology in the South Yellow Sea Basin.展开更多
The improved granular mixtures are widely used as the fillings of railway 8ubgrade, and in order to investigate the effect of coarse grain content on granular mixtures, a series of field tests were conducted. The expe...The improved granular mixtures are widely used as the fillings of railway 8ubgrade, and in order to investigate the effect of coarse grain content on granular mixtures, a series of field tests were conducted. The experimental results indicate that the permeability coefficient increases significantly with the increment of granite gravel content, especially in the range of 60%-70%. Thcrc exists a coarse grain content limit defined as 53%-58.5% to reform the permeable granular skeleton. Beyond this limit, the permeable granular skeleton is efficiently formed, and the macro pores between the separate gravels are partially filled, which is the explanation lbr the permeability increase. The investigations indicate the subgrade resistance modulus （ks0, Ev2, and Evd） depends on the granite gravel content, and the resistance modulus increases significantly beyond granite gravel content of 50%. The skeletons of granitc gravel clayey sand mixture change in the long-term deformation objected to the train-induced dynamic load, which involves three main repeated and circular deformation stages. Generally, the long-time deformation is explained as the gravel crushing and filling the internal porous space with crushed gravel fragments. Through these investigations, the C40-G60 or C30-G70 is recommended as an optimum soil mixture for the good permeability and high resistance modulus.展开更多
The dynamic model experiment of the rock filling embankment was carried out to investigate the vibration compaction mechanism. The rock filling materials were compacted by the plate-vibrated compactor, and the charact...The dynamic model experiment of the rock filling embankment was carried out to investigate the vibration compaction mechanism. The rock filling materials were compacted by the plate-vibrated compactor, and the characteristics of the rock filling materials, such as settlement, pressure change and response waveform, were measured by the dynamic earth pressure gauge and aceelerometer. Moreover, a new method for detecting the compactness of the rock filling embankment was proposed based on the maximum dry density and modulus of deformation. The results show that the process of vibration compaction includes compact, elastic deformation and loose stages, and the vibratory pressure transfers to the surroundings from the vibration center in non-linear rule. Furthermore, the test results obtained by the present method are basically in agreement with those obtained by the traditional method, and the maximum relative error between them is about 0.5%.展开更多
In order to discuss the buckling stability of super-long rock-socketed filling piles widely used in bridge engineering in soft soil area such as Dongting Lake, the second stability type was adopted instead of traditio...In order to discuss the buckling stability of super-long rock-socketed filling piles widely used in bridge engineering in soft soil area such as Dongting Lake, the second stability type was adopted instead of traditional first type, and a newly invented numerical analysis method, i.e. the element-free Galerkin method (EFGM), was introduced to consider the non-concordant deformation and nonlinearity of the pile-soil interface. Then, based on the nonlinear elastic-ideal plastic pile-soil interface model, a nonlinear iterative algorithm was given to analyze the pile-soil interaction, and a program for buckling analysis of piles by the EFGM (PBAP-EFGM) and arc length method was worked out as well. The application results in an engineering example show that, the shape of pile top load-settlement curve obtained by the program agrees well with the measured one, of which the difference may be caused mainly by those uncertain factors such as possible initial defects of pile shaft and the eccentric loading during the test process. However, the calculated critical load is very close with the measured ultimate load of the test pile, and the corresponding relative error is only 5.6%, far better than the calculated values by linear and nonlinear incremental buckling analysis (with a greater relative error of 37.0% and 15.4% respectively), which also verifies the rationality and feasibility of the present method.展开更多
For improving global stability of mining environment reconstructing structure,the stress field evolution law of the structure with the filling height change of low-grade backfill was studied by ADINA finite element an...For improving global stability of mining environment reconstructing structure,the stress field evolution law of the structure with the filling height change of low-grade backfill was studied by ADINA finite element analysis code.Three kinds of filling schemes were designed and calculated,in which the filling heights were 2,4,and 7 m,separately.The results show that there are some rules in the stress field with the increase of the filling height as follows:(1) the maximum value of tension stress of the roof decreases gradually,and stress conditions are improved gradually;(2) the tension stress status in the vertical pillar is transformed into the compressive stress status,and the carrying capacity is improved gradually;however,when the filling height is beyond 2.8 m,the carrying capacity of the vertical pillar grows very slowly,so,there is little significance to continue to fill the low-grade backfill;(3) the bottom pillar suffers the squeezing action from the vertical pillars at first and then the gravity action of the low-grade backfill,and the maximum value of tension stress of the bottom pillar firstly increases and then decreases.Considering the economic factor,security and other factors,the low-grade backfill has the most reasonable height(2.8 m) in the scope of all filling height.展开更多
The present problem of mining of narrow and gentle dip vein was analyzed. A new technique of rapidly following curtain filling was put forward. The results show that the new technique is feasible, has the characterist...The present problem of mining of narrow and gentle dip vein was analyzed. A new technique of rapidly following curtain filling was put forward. The results show that the new technique is feasible, has the characteristic to make the whole curtain wall filter, makes relative density of the filling tailings slurry reach saturation of 78.0% 80.0% in 25 min, and keeps the roof of mined out space stable in 60 min. The new technique of the rapidly following curtain filling has solved the difficult problem of the filling body filtering slowly and promptly controlling underground pressure, which cannot be solved in traditional ways.展开更多
The paper puts forward a highly efficient and practical scan line based on the filling algorithm. The algorithm takes the lines of polygon as line segments with directions and introduces the concept of marked value wh...The paper puts forward a highly efficient and practical scan line based on the filling algorithm. The algorithm takes the lines of polygon as line segments with directions and introduces the concept of marked value when the apex of polygon faces scan line, determines whether there are intersection points between the lines of polygon and scan lines, by judging whether the marked value has changed or not. This method avoids the extra decision and treatment of odd points in traditional algorithm, and it needs little calculations but it is highly efficient.展开更多
A stratigraphic and depositional filling modal of Triassic—Jurassic North Tarim foreland basin system is erected, through synthetic analysis of geological setting, depositional provenance, sequence stratigraphy, and ...A stratigraphic and depositional filling modal of Triassic—Jurassic North Tarim foreland basin system is erected, through synthetic analysis of geological setting, depositional provenance, sequence stratigraphy, and quantitative tectonic stratigraphy. The result suggests that the major factors controlling formation and evolution of the system are oblique collision and convergence of different plates, and favorite hydrocarbon plays is predicted.The geological setting analysis emphasizes the historical succession of the foreland basin system formation and evolution. The tectonic setting analysis sketchy outlines formation of the system and tectonic setting of its successive evolution. The sedimentary geology analysis reveals the uplift and subsidence of the basin basement a seesaw style movement.展开更多
The casting nozzle location plays an important role in die casting. Improper location results in defects, such as cold shut, air cavity, shrinkage, etc. Therefore, it’s sure that the molten metal full fills the mould...The casting nozzle location plays an important role in die casting. Improper location results in defects, such as cold shut, air cavity, shrinkage, etc. Therefore, it’s sure that the molten metal full fills the mould cavity before it solidifies. And, it’s to be wished that no vortex occur during the filling process, because the vortex is a main source that induces gas entrapment. To get the high quality and performance product, the inlet and outlet locations must be set properly. This paper, an optimal design problem of nozzle and vent locations, which is constrained by nonlinear partial differential equations and boundary and initial conditions, is introduced to describe the location selection on die casting filling process. By numerical simulation, one can compare the filling time, flow pattern and temperature field at different inlet and outlet locations, then choose the most proper locations.展开更多
Mathematical model of filling disk-shaped mold cavity in steady state was studied.And the mathematical model under vibration field was developed from the model in steady state.According to the model of filling disk-sh...Mathematical model of filling disk-shaped mold cavity in steady state was studied.And the mathematical model under vibration field was developed from the model in steady state.According to the model of filling disk-shaped mold cavity in steady state,the filling time,the distribution of velocity field and the pressure field were obtained.The analysis results from rheological analytic model were compared with the numerical simulation results using Moldflow software in the powder injection molding filling process.Through the comparison,it is found that it is unreasonable to neglect the influence of temperature when calculated the pressure changing with the time at the cavity gate,while it can be neglected in other situations such as calculating the distribution of the velocity fields.This provides a theoretical reference for the establishment of correct model both in steady state and under vibration force field in the future.展开更多
The relation and unity of the tectonic process and sedimentation is being paid a good deal of attention. It is very obvious that the sedimentary process of the terrestrial basin is controlled by tectogenesis. The sedi...The relation and unity of the tectonic process and sedimentation is being paid a good deal of attention. It is very obvious that the sedimentary process of the terrestrial basin is controlled by tectogenesis. The sedimentary evolution of the basin is the reflection of the tectonic evolution . The sedimentary process of the terrestrial basin has unique characteristics.(1) The scope of the terrestrial basin is mainly controlled by the fault zones.(2) The regional tectonic cycle obviously controls the sedimentary sequence boundary of the terrestrial basin. The periodicity of tectogenesis causes the periodic change of the sedimentary sequence.(3) The sedimentary model of the terrestrial basin is obviously controlled by the tectonic framework.(4) There are many surprise sedimentary events in sedimentary formation of the terrestrial basin.(5) Owing to the influence of the tectonization, the deformation frequently occurs in the sedimentary deposit.(6) Because the sediments of the terrestrial basin have the short\|distance transport, the sediments have the low mature index.(7) There are more sedimentary centres, more matter\|sources, narrow sedimentary facies\|zone and the quick facies change in the terrestrial basin.According to the background of the tectonic dynamics, the terrestrial basin can be divided into the extension basin, the compression basin and the shear basin. The three basins differ greatly in the sedimentary characteristics. The extension basin is usually directed at rift basin. The border of the extension basin is mainly the normal fault or growth fault. The plane shape of the extension is zone\|shape. The sedimentary deposit of the extension basin has not strong deformation. The thickness of the sediment on the downthrow wall is greater than that the sediment on the upcast wall. The periodic change of the tectogenesis causes the enlarging or the contract of the extension basin.展开更多
文摘The effect of coix seed flour(0%–25%)on the rheological and structural properties of wheat dough and noodle quality was investigated.The addition of coix seed flour was found to enhance the elasticity of dough,which may be attributed to the fact that small starch particles increase the filling capacity within the dough matrix.This increase subsequently resulted in more complete and uniform structure of dough.Moreover,setback viscosity rose to 1095 cP.The rapid water absorption of coix seed starch led to changes in the secondary structure of proteins in dough.The proportion ofβ-sheet markedly increased,whereas the proportion ofα-helix decreased with increasing level of coix seed flour substitution.Meanwhile,coix seed flour substitution significantly reduced the estimated glycemic index of noodles.Correlation analysis revealed that pasting parameters had significant effects on the evaluation of noodle quality.This study provides a foundation for researchers to substitute wheat flour with coix seed flour.
文摘【Background】The application of beneficial-microbial seed soaking prior to sowing represents a novel technology that has not been employed in Lanzhou lily cultivation.We conducted an experiment to explore the impact of this soaking method on the fungal and bacterial community structures using next-generation sequencing technology(NGS).【Methods】Lily bulbs were soaked in a seed treating agent containing beneficial microbes(SP treatment)for 4 hours.Subsequently,they were planted in soil in July and sampled in September to assess plant growth,rhizosphere soil physicochemical properties,and microorganism community structures.In addition,we employed the software PICRUSt and FUNGuild to predict bacterial pathways and fungal functions.【Results】Under SP treatment,there were significant alterations in fungi and bacteria community structures,accompanied by improved soil nutrient status.Notably,the relative abundance of dominant microorganism groups,such as the fungi Basidiomycota,Pseudeurotium,Cladophialophora,Microascus,and Dactylonectria,as well as the bacteria Proteobacteria,Chloroflexi,Ochrobactrium,Lysobacter,and RB41,underwent notable changes.Microorganism function prediction results indicated a reduction in pathotrophic fungi(including plant pathogens)and an increase in endophytic and saprotrophic fungi under SP treatment.Among the top 20 metabolism pathways,80%were upregulated in SP treatment compared to the CK.【Conclusions】Seed soaking with beneficial microbial strain promotes the growth of Lanzhou lily bulbs.The beneficial microorganisms play a crucial role in regulating soil microbial structures,enhancing the accumulation of endophytic fungi,reducing the abundance of pathogens,and improving soil functions.Furthermore,specific microbial groups are found to be involved in maintaining soil health.
基金the Indian Council of Agriculture Research-National Agriculture Higher Education Program(No.A4/003026/2023)to carry out this work during the international faculty training program at Nanyang Technological University,Singapore,under the Institution Development Plan.
文摘Cotton,a crucial commercial fibre crop,depends heavily on seed-associated characteristics like germination rate,vigour,and resistance to post-harvest deterioration for both production and lint quality.Serious cellular damage dur-ing post-harvest processes such as delinting,prolonged seedling emergence periods,decreased viability,increased susceptibility to infections,and lipid peroxidation during storage pose serious problems to seed quality.The perfor-mance of seeds and total crop productivity are adversely affected by these problems.Traditional methods of seed improvement,like physical scarification and seed priming,have demonstrated promise in raising cotton seed vigour and germination rates.Furthermore,modern approaches including plasma therapies,magnetic water treatments,and nanotechnology-based treatments have shown promise in improving seed quality and reducing environmen-tal stresses.By offering sustainable substitutes for conventional approaches,these cutting-edge procedures lessen the need for fungicides and other agrochemicals that pollute the environment.This review explores various con-ventional and emerging strategies to address the detrimental factors impacting cotton seed quality.It emphasizes the importance of integrating classical and advanced approaches to enhance germination,ensure robust crop estab-lishment,and achieve higher yields.In addition to promoting sustainable cotton production,this kind of integration helps preserve the ecosystem and create resilient farming methods.
基金Project(52374153)supported by the National Natural Science Foundation of ChinaProject(kq2502150)supported by the Natural Science Foundation of Changsha,China。
文摘Cemented tailings backfill(CTB)is a crucial support material for ensuring the long-term stability of underground goafs.A comprehensive understanding of its compressive mechanical behavior is essential for improving engineering safety.Although extensive studies have been conducted on the uniaxial compressive properties of CTB,damage constitutive models that effectively capture its damage evolution process remain underdeveloped,and its failure mechanisms are not yet fully clarified.To address these gaps,this study conducted systematic uniaxial compression tests on CTB specimens prepared with varying cement-tailings ratios.The results revealed distinct compaction and softening phases in the stress−strain curves.A lower cement-tailings ratio significantly reduced the strength and deformation resistance of CTB,along with a decrease in elastic energy accumulation at peak stress and dissipation energy in the post peak stage.Based on these findings,a modified damage constitutive model was developed by introducing a correction factor,enabling accurate simulation of the entire uniaxial compression process of CTB with different cement-tailings ratios.Comparative analysis with classical constitutive models validated the proposed model’s accuracy and applicability in describing the compressive behavior of CTB.Furthermore,particle size distribution and acoustic emission tests were employed to investigate the influence of cement-tailings ratio on failure mechanisms.The results indicated that a lower cement-tailings ratio leads to coarser particle sizes,which intensify shear-related acoustic emission signals and ultimately result in more pronounced macroscopic shear failure.This study provides theoretical support and practical guidance for the optimal design of CTB mix ratios.
基金the National Natural Science Foundation of China(Grant Nos.52371342,52271338,52101378 and 51979277)。
文摘This study designs four types of liquid-filled cylindrical shell structures to investigate their protection characteristics against explosive shock waves and high-speed fragments.Bare charge and charge-driven prefabricated fragments are employed to examine the damage under blast shock waves and combined blast and fragments loading on various liquid-filled cylindrical shell structures.The test results are compared to numerical calculations and theoretical analysis for the structure's deformation,the liquid medium's movement,and the pressure waves'propagation characteristics under different liquid-filling methods.The results showed that the filling method influences the blast protection and the struc-ture's energy absorption performance.The external filling method reduces the structural deformation,and the internal filling method increases the damage effect.The gapped internal filling method improves the structure's energy absorption efficiency.The pressure wave loading on the liquid-filled cylindrical shell structure differs depending on filling methods.Explosive shock waves and high-speed fragments show a damage enhancement effect on the liquid-filled cylindrical shell structure,depending on the thickness of the internal liquid container layer.The specific impulse on the inner surface of the cylindrical shell positively correlates to the radial deformation of the cylindrical shell structure,and the external liquid layer limits the radial structural deformation.
基金Project(2012BAK09B02-05)supported by the National Science and Technology Pillar Program during the 12th Five-Year Plan PeriodProject(11KF02)supported by the Research Fund of the State Key Laboratory of Coal Resources and Mine Safety
文摘Longhole caving method was used to mine gently inclined thick orebody step by step in a test stope of tin mine under complex filling body. The problem that the complex filling body around the stope affects the stability of roof thickness, chamber and spacer pillar in actual mining was investigated; meanwhile, the formed goaf during mining is so vulnerable that surrounding rock collapses early. Based on this point, elasticity mechanics and limit span theory were used to study separately the roof thickness and the span limit of goaf formed in mining, and then a reasonable roof thickness of 8 m and goaf span of 14 m are proposed. In addition, the stability of roof thickness, chamber and spacer pillar were investigated and analyzed by using numerical analysis method; meanwhile, the field monitoring on the displacement of caving chamber was conducted. The results show that the maximum compressive stress of surrounding rock is 20 MPa, and the maximum tensile stress is 1.2 MPa, which is less than the ultimate tensile strength of 2.4 MPa. Moreover, plastic zone has little influence on stope stability. In addition, the displacement of 11 mm is also smaller. The displacement monitoring results are consistent with the numerical results. Thus, the roof thickness and span of goaf proposed are safe.
基金Projects(51974225,51874229,51674188,51904224,51904225,51504182) supported by the National Natural Science Foundation of ChinaProjects(2018JM5161,2018JQ5183,2015JQ5187) supported by the Natural Science Basic Research Plan of Shaanxi,China
文摘It is the basic requirement of the synergetic exploitation of deep mineral resources and geothermal resources to arrange the heat transfer tube in filling body. The heat release performance of filling body directly impacts on the exploiting efficiency of geothermal energy. Based on heat transfer theory, a three-dimensional unsteady heat transfer model of filling body is established by using FLUENT simulation software. Taking the horizontal U-shaped buried pipe as research object, the variation of temperature field in filling body around buried pipe is analyzed during the heat release process of filling body;the initial temperature of filling body, the diameter of buried pipe, the inlet temperature and inlet velocity of heat transfer fluid influencing of coupling heat transfer, which exists between heat transfer fluid and surrounding filling body within a certain axial distance of buried tube, and influencing of temperature difference between inlet and outlet of heat transfer fluid and on heat transfer performance of filling body are also discussed. It not only lays a theoretical foundation for the synergetic exploitation of mineral resources and geothermal energy in deep mines, but also provides a reference basis for the arrangement of buried pipes in filling body as well as the selection of working conditions for heat transfer fluid.
基金Projects(51778386,51708377,51608059)supported by the National Natural Science Foundation of ChinaProject(BK20170339)supported by Natural Science Foundation of Jiangsu Province,China+2 种基金Project(17KJB560008)supported by Natural Science Fund for Colleges and Universities in Jiangsu Province,ChinaProjects(KFJ170106,KFJ180105)supported by Open Fund of National Engineering Laboratory of Highway Maintenance Technology(Changsha University of Science&Technology),ChinaProjects(2016ZD18,2017ZD002)supported by Jiangsu Provincial Department of Housing,Urban-Rural Development,China。
文摘The treatment of contaminated soil is a crucial issue in geotechnical and environmental engineering.This study proposes to incorporate appropriate polypropylene fibers and cements as an effective method to treat heavy metal contaminated soil(HMCS).The objective of this paper is to investigate the effects of fiber content,fiber length,cement content,curing time,heavy metal types and concentration on the mechanical properties of soils.To this end,a series of direct shear test,unconfined compression strength(UCS)test,dry-wet cycle and freeze-thaw cycle test are performed.The results confirm that the appropriate reinforcement of polypropylene fibers and cement is an effective way to recycle HMCS as substitutable fillers in roadbed,which exhibits benefits in environment and economy development.
基金Projects(41506080,41702162)supported by the National Natural Science Foundation of ChinaProjects(DD20160152,DD20160147,GZH200800503)supported by China Geological Survey+1 种基金Projects(XQ-2005-01,2009GYXQ10)supported by China Ministry of Land and ResourcesProject(201602004)supported by the Postdoctoral Innovation Foundation of Shandong Province,China
文摘In the South Yellow Sea Basin,Mesozoic–Paleozoic marine strata are generally well developed with large thickness,and no substantial breakthroughs have been made in hydrocarbon exploration.Through research,it is believed that the Upper Permian–Lower Triassic can be regarded as a long-term base-level cycle.Based on drilling data,characteristics of the lithology–electric property combination cyclicity,and the special lithology,the long-term base-level cycle was divided into five medium-term base-level cycles(MC1–MC5).On this basis,the Permian–Triassic sedimentary systems and their filling model were analyzed in accordance with the change of base-level cycle and transition of sedimentary environment,as well as characteristics of the drilling sedimentary facies and seismic facies.The results show that there were six sedimentary systems(fluvial,delta,tidal flat,open platform,restricted platform,and continental shelf)developed in the Upper Permian–Lower Triassic,the sedimentary systems were distributed such that the water was deep in the northwest and shallow in the southeast,and there were two base-level cycle filling models(a relatively stable tidal flat facies and a rapidly transgressive continental shelf facies to stable platform facies)developed in the Upper Permian–Lower Triassic.These models can provide a basis for evaluation of the Mesozoic–Paleozoic hydrocarbon geology in the South Yellow Sea Basin.
基金Project(51378514)supported by the National Natural Science Foundation of China
文摘The improved granular mixtures are widely used as the fillings of railway 8ubgrade, and in order to investigate the effect of coarse grain content on granular mixtures, a series of field tests were conducted. The experimental results indicate that the permeability coefficient increases significantly with the increment of granite gravel content, especially in the range of 60%-70%. Thcrc exists a coarse grain content limit defined as 53%-58.5% to reform the permeable granular skeleton. Beyond this limit, the permeable granular skeleton is efficiently formed, and the macro pores between the separate gravels are partially filled, which is the explanation lbr the permeability increase. The investigations indicate the subgrade resistance modulus （ks0, Ev2, and Evd） depends on the granite gravel content, and the resistance modulus increases significantly beyond granite gravel content of 50%. The skeletons of granitc gravel clayey sand mixture change in the long-term deformation objected to the train-induced dynamic load, which involves three main repeated and circular deformation stages. Generally, the long-time deformation is explained as the gravel crushing and filling the internal porous space with crushed gravel fragments. Through these investigations, the C40-G60 or C30-G70 is recommended as an optimum soil mixture for the good permeability and high resistance modulus.
基金Project (50708033) supported by the National Natural Science Foundation of ChinaProject (20070532067) supported by Doctoral Foundation of Ministry of Education of China
文摘The dynamic model experiment of the rock filling embankment was carried out to investigate the vibration compaction mechanism. The rock filling materials were compacted by the plate-vibrated compactor, and the characteristics of the rock filling materials, such as settlement, pressure change and response waveform, were measured by the dynamic earth pressure gauge and aceelerometer. Moreover, a new method for detecting the compactness of the rock filling embankment was proposed based on the maximum dry density and modulus of deformation. The results show that the process of vibration compaction includes compact, elastic deformation and loose stages, and the vibratory pressure transfers to the surroundings from the vibration center in non-linear rule. Furthermore, the test results obtained by the present method are basically in agreement with those obtained by the traditional method, and the maximum relative error between them is about 0.5%.
基金Project(50378036) supported by the National Natural Science Foundation of China
文摘In order to discuss the buckling stability of super-long rock-socketed filling piles widely used in bridge engineering in soft soil area such as Dongting Lake, the second stability type was adopted instead of traditional first type, and a newly invented numerical analysis method, i.e. the element-free Galerkin method (EFGM), was introduced to consider the non-concordant deformation and nonlinearity of the pile-soil interface. Then, based on the nonlinear elastic-ideal plastic pile-soil interface model, a nonlinear iterative algorithm was given to analyze the pile-soil interaction, and a program for buckling analysis of piles by the EFGM (PBAP-EFGM) and arc length method was worked out as well. The application results in an engineering example show that, the shape of pile top load-settlement curve obtained by the program agrees well with the measured one, of which the difference may be caused mainly by those uncertain factors such as possible initial defects of pile shaft and the eccentric loading during the test process. However, the calculated critical load is very close with the measured ultimate load of the test pile, and the corresponding relative error is only 5.6%, far better than the calculated values by linear and nonlinear incremental buckling analysis (with a greater relative error of 37.0% and 15.4% respectively), which also verifies the rationality and feasibility of the present method.
基金Project(200911MS01) supported by the Scientific Research Fund of Guangxi Provincial Education Department, China Project (XBZ100126) supported by the Scientific Research Foundation of Guangxi University, China Project(2009B005) supported by the Teaching Reform Foundation in the New Century Higher Education of Guangxi Province,China
文摘For improving global stability of mining environment reconstructing structure,the stress field evolution law of the structure with the filling height change of low-grade backfill was studied by ADINA finite element analysis code.Three kinds of filling schemes were designed and calculated,in which the filling heights were 2,4,and 7 m,separately.The results show that there are some rules in the stress field with the increase of the filling height as follows:(1) the maximum value of tension stress of the roof decreases gradually,and stress conditions are improved gradually;(2) the tension stress status in the vertical pillar is transformed into the compressive stress status,and the carrying capacity is improved gradually;however,when the filling height is beyond 2.8 m,the carrying capacity of the vertical pillar grows very slowly,so,there is little significance to continue to fill the low-grade backfill;(3) the bottom pillar suffers the squeezing action from the vertical pillars at first and then the gravity action of the low-grade backfill,and the maximum value of tension stress of the bottom pillar firstly increases and then decreases.Considering the economic factor,security and other factors,the low-grade backfill has the most reasonable height(2.8 m) in the scope of all filling height.
文摘The present problem of mining of narrow and gentle dip vein was analyzed. A new technique of rapidly following curtain filling was put forward. The results show that the new technique is feasible, has the characteristic to make the whole curtain wall filter, makes relative density of the filling tailings slurry reach saturation of 78.0% 80.0% in 25 min, and keeps the roof of mined out space stable in 60 min. The new technique of the rapidly following curtain filling has solved the difficult problem of the filling body filtering slowly and promptly controlling underground pressure, which cannot be solved in traditional ways.
文摘The paper puts forward a highly efficient and practical scan line based on the filling algorithm. The algorithm takes the lines of polygon as line segments with directions and introduces the concept of marked value when the apex of polygon faces scan line, determines whether there are intersection points between the lines of polygon and scan lines, by judging whether the marked value has changed or not. This method avoids the extra decision and treatment of odd points in traditional algorithm, and it needs little calculations but it is highly efficient.
文摘A stratigraphic and depositional filling modal of Triassic—Jurassic North Tarim foreland basin system is erected, through synthetic analysis of geological setting, depositional provenance, sequence stratigraphy, and quantitative tectonic stratigraphy. The result suggests that the major factors controlling formation and evolution of the system are oblique collision and convergence of different plates, and favorite hydrocarbon plays is predicted.The geological setting analysis emphasizes the historical succession of the foreland basin system formation and evolution. The tectonic setting analysis sketchy outlines formation of the system and tectonic setting of its successive evolution. The sedimentary geology analysis reveals the uplift and subsidence of the basin basement a seesaw style movement.
文摘The casting nozzle location plays an important role in die casting. Improper location results in defects, such as cold shut, air cavity, shrinkage, etc. Therefore, it’s sure that the molten metal full fills the mould cavity before it solidifies. And, it’s to be wished that no vortex occur during the filling process, because the vortex is a main source that induces gas entrapment. To get the high quality and performance product, the inlet and outlet locations must be set properly. This paper, an optimal design problem of nozzle and vent locations, which is constrained by nonlinear partial differential equations and boundary and initial conditions, is introduced to describe the location selection on die casting filling process. By numerical simulation, one can compare the filling time, flow pattern and temperature field at different inlet and outlet locations, then choose the most proper locations.
基金Project(10672197) supported by the National Natural Science Foundation of ChinaProject(07JJ1001) supported by the Natural Science Foundation of Hunan Province for Distinguished Young Scholars,China
文摘Mathematical model of filling disk-shaped mold cavity in steady state was studied.And the mathematical model under vibration field was developed from the model in steady state.According to the model of filling disk-shaped mold cavity in steady state,the filling time,the distribution of velocity field and the pressure field were obtained.The analysis results from rheological analytic model were compared with the numerical simulation results using Moldflow software in the powder injection molding filling process.Through the comparison,it is found that it is unreasonable to neglect the influence of temperature when calculated the pressure changing with the time at the cavity gate,while it can be neglected in other situations such as calculating the distribution of the velocity fields.This provides a theoretical reference for the establishment of correct model both in steady state and under vibration force field in the future.
文摘The relation and unity of the tectonic process and sedimentation is being paid a good deal of attention. It is very obvious that the sedimentary process of the terrestrial basin is controlled by tectogenesis. The sedimentary evolution of the basin is the reflection of the tectonic evolution . The sedimentary process of the terrestrial basin has unique characteristics.(1) The scope of the terrestrial basin is mainly controlled by the fault zones.(2) The regional tectonic cycle obviously controls the sedimentary sequence boundary of the terrestrial basin. The periodicity of tectogenesis causes the periodic change of the sedimentary sequence.(3) The sedimentary model of the terrestrial basin is obviously controlled by the tectonic framework.(4) There are many surprise sedimentary events in sedimentary formation of the terrestrial basin.(5) Owing to the influence of the tectonization, the deformation frequently occurs in the sedimentary deposit.(6) Because the sediments of the terrestrial basin have the short\|distance transport, the sediments have the low mature index.(7) There are more sedimentary centres, more matter\|sources, narrow sedimentary facies\|zone and the quick facies change in the terrestrial basin.According to the background of the tectonic dynamics, the terrestrial basin can be divided into the extension basin, the compression basin and the shear basin. The three basins differ greatly in the sedimentary characteristics. The extension basin is usually directed at rift basin. The border of the extension basin is mainly the normal fault or growth fault. The plane shape of the extension is zone\|shape. The sedimentary deposit of the extension basin has not strong deformation. The thickness of the sediment on the downthrow wall is greater than that the sediment on the upcast wall. The periodic change of the tectogenesis causes the enlarging or the contract of the extension basin.
