A new back-analysis method of ground stress is proposed with comprehensive consideration of influence of topography, geology and nonlinear physical mechanical properties of rock on ground stress. This method based on ...A new back-analysis method of ground stress is proposed with comprehensive consideration of influence of topography, geology and nonlinear physical mechanical properties of rock on ground stress. This method based on non-uniform rational B-spline (NURBS) technology provides the means to build a refined three-dimensional finite element model with more accurate meshing under complex terrain and geological conditions. Meanwhile, this method is a back-analysis of ground stress with combination of multivariable linear regression model and neural network (ANN) model. Firstly, the regression model is used to fit approximately boundary loads. Regarding the regressed loads as mean value, some sets of boundary loads with the same interval are constructed according to the principle of orthogonal design, to calculate the corresponding ground stress at the observation positions using finite element method. The results (boundary loads and the corresponding ground stress) are added to the samples for ANN training. And on this basis, an ANN model is established to implement higher precise back-analysis of initial ground stress. A practical application case shows that the relative error between the inversed ground stress and observed value is mostly less than 10 %, which can meet the need of engineering design and construction requirements.展开更多
A definition of combined phase center for horn feeds is given.Formulas of E-planeand H-plane combined phase center for conical horns and the corresponding Optimal model arepresented,and a fast optimization method for ...A definition of combined phase center for horn feeds is given.Formulas of E-planeand H-plane combined phase center for conical horns and the corresponding Optimal model arepresented,and a fast optimization method for solving this model is described.By using thismethod,the phase center of corrugated horn is discussed and calculated,and the variation of thephase center with distance and operating frequency is given.展开更多
Existing“evaluation indicators”are selected and combined to build a model to support the optimization of shale gas horizontal wells.Towards this end,different“weighting methods”,including AHP and the so-called ent...Existing“evaluation indicators”are selected and combined to build a model to support the optimization of shale gas horizontal wells.Towards this end,different“weighting methods”,including AHP and the so-called entropy method,are combined in the frame of the game theory.Using a relevant test case for the implementation of the model,it is shown that the horizontal section of the considered well is in the middle sweet spot area with good physical properties and fracturing ability.In comparison with the FSI(flow scanner Image)gas production profile,the new model seems to display better abilities for the optimization of horizontal wells.展开更多
Soil erosion has been recognized as a critical environmental issue worldwide.While previous studies have primarily focused on watershed-scale soil erosion vulnerability from a natural factor perspective,there is a not...Soil erosion has been recognized as a critical environmental issue worldwide.While previous studies have primarily focused on watershed-scale soil erosion vulnerability from a natural factor perspective,there is a notable gap in understanding the intricate interplay between natural and socio-economic factors,especially in the context of spatial heterogeneity and nonlinear impacts of human-land interactions.To address this,our study evaluates the soil erosion vulnerability at a provincial scale,taking Hubei Province as a case study to explore the combined effects of natural and socio-economic factors.We developed an evaluation index system based on 15 indicators of soil erosion vulnerability:exposure,sensitivity,and adaptability.In addition,the combination weighting method was applied to determine index weights,and the spatial interaction was analyzed using spatial autocorrelation,geographical temporally weighted regression and geographical detector.The results showed an overall decreasing soil erosion intensity in Hubei Province during 2000 and 2020.The soil erosion vulnerability increased before 2000 and then.The areas with high soil erosion vulnerability were mainly confined in the central and southern regions of Hubei Province(Xiantao,Tianmen,Qianjiang and Ezhou)with obvious spatial aggregation that intensified over time.Natural factors(habitat quality index)had negative impacts on soil erosion vulnerability,whereas socio-economic factors(population density)showed substantial spatial variability in their influences.There was a positive correlation between soil erosion vulnerability and erosion intensity,with the correlation coefficients ranging from-0.41 and 0.93.The increase of slope was found to enhance the positive correlation between soil erosion vulnerability and intensity.展开更多
Ultra-deep and complex formations are characterized by narrow safety density windows and challenging well control.The combined use of multiple well-killing methods or temporary adjustments to well-killing strategies i...Ultra-deep and complex formations are characterized by narrow safety density windows and challenging well control.The combined use of multiple well-killing methods or temporary adjustments to well-killing strategies is becoming common.However,conventional well-killing models often struggle to calculate the parameters required for these special cases.In this paper,a boundary matrix for wellkilling fluid density and volume is proposed to unify the driller's method,the engineer's method,and the weight-while-circulating method.Furthermore,a dynamic unified well-killing model is developed to enable the synergistic regulation of multiple well-killing methods.The model also can be applied with or without accounting for gas dissolution.Using this model,it is able to dynamically track key parameters during well killing and shut in the well at any time to determine the standpipe and casing pressures.The results indicate that the casing pressure drops to zero before the well-killing fluid returns to the annulus wellhead,and continued injection of the fluid leads to a gradual increase in standpipe pressure,a phenomenon not previously accounted for.The discrepancy between the actual and calculated standpipe/casing pressures after shut-in can be utilized to assess whether the downhole gas kick is effectively controlled.Through real-time adjustments to the boundary matrix,updated wellkilling parameters can be derived for conventional method,multi-method combination,temporary strategy modification,and other well-killing scenarios.The model was applied to two field wells under water-and oil-based drilling fluids.No secondary downhole complications occurred during well killing,and the calculated pressure curves closely matched the measured construction pressure curves,confirming the model's reliability and applicability.This study provides valuable theoretical guidance for enhancing well control safety in ultra-deep and complex formations.展开更多
This paper proposes a structure combined by baffle and submerged breakwater （abbreviated to SCBSB in the following texts）. Such a combined structure is conducive to the water exchange in the harbor, and has strong c...This paper proposes a structure combined by baffle and submerged breakwater （abbreviated to SCBSB in the following texts）. Such a combined structure is conducive to the water exchange in the harbor, and has strong capability on wave dissipation. Our paper focuses on the discussion of two typical structures, i.e., the submerged baffle and rectangular breakwater combined with the upper baffle respectively, which are named as SCBSB 1 and SCBSB2 for short. The eigenfunction method corrected by experimental results is used to investigate the wave dissipation characteristics. It shows that the calculated results agree well with the experimental data and the minimum value of the wave transmission coefficient can be obtained when the distance between the front and rear structures is from 1/4 to 1/2 of the incident wave length.展开更多
The pit limit optimization is discussed, which is one of the most important problems in the combined min-ing method, on the basis of the economic model of ore-blocks. A new principle of the limit optimization is put f...The pit limit optimization is discussed, which is one of the most important problems in the combined min-ing method, on the basis of the economic model of ore-blocks. A new principle of the limit optimization is put for-ward through analyzing the limitations of moving cone method under such conditions. With a view to recovering asmuch mineral resource as possible and making the maximum profit from the whole deposit, the new principle is tomaximize the sum of gain from both open-pit and underground mining. The mathematical models along the horizon-tal and vertical directions and modules for software package (DM&MCAD) have been developed and tested inTonglushan Copper Mine. It has been proved to be rather effective in the mining practice.展开更多
Combinatorial drug therapies are generally more effective than monotherapies in treating viral infections.However,it is critical for dose optimization to maximize the efficacy and minimize side effects.Although variou...Combinatorial drug therapies are generally more effective than monotherapies in treating viral infections.However,it is critical for dose optimization to maximize the efficacy and minimize side effects.Although various strategies have been devised to accelerate the optimization process,their efficiencies were limited by the high noises and suboptimal reproducibility of biological assays.With conventional methods,variances among the replications are used to evaluate the errors of the readouts alone rather than actively participating in the optimization.Herein,we present the Regression Modeling Enabled by Monte Carlo Method(ReMEMC)algorithm for rapid identification of effective combinational therapies.ReMEMC transforms the sample variations into probability distributions of the regression coefficients and predictions.In silico simulations revealed that ReMEMC outperformed conventional regression methods in benchmark problems,and demonstrated its superior robustness against experimental noises.Using COVID-19 as a model disease,ReMEMC successfully identified an optimal 3-drug combination among 10 anti-SARS-CoV-2 drug compounds within two rounds of experiments.The optimal combination showed 2-log and 3-log higher load reduction than non-optimized combinations and monotherapy,respectively.Further workflow refinement allowed identification of personalized drug combinational therapies within 5 days.The strategy may serve as an efficient and universal tool for dose combination optimization.展开更多
In the context of advancing towards dual carbon goals,numerous factories are actively engaging in energy efficiency upgrades and transformations.To accurately pinpoint energy efficiency bottlenecks within factories an...In the context of advancing towards dual carbon goals,numerous factories are actively engaging in energy efficiency upgrades and transformations.To accurately pinpoint energy efficiency bottlenecks within factories and prioritize renovation sequences,it is crucial to conduct comprehensive evaluations of the energy performance across various workshops.Therefore,this paper proposes an evaluation model for workshop energy efficiency based on the drive-state-response(DSR)framework combined with the fuzzy BORDA method.Firstly,an in-depth analysis of the relationships between different energy efficiency indicators was conducted.Based on the DSR model,evaluation criteria were selected from three dimensions-drive factors,state characteristics,and response measures-to establish a robust energy efficiency indicator system.Secondly,three distinct assessment techniques were selected:Grey Relational Analysis(GRA),Entropy Weight Method(EWM),and Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)forming a diversified set of evaluation methods.Subsequently,by introducing the fuzzy BORDA method,a comprehensive energy efficiency evaluation model was developed,aimed at quantitatively ranking the energy performance status of each workshop.Using a real-world factory as a case study,applying our proposed evaluationmodel yielded detailed scores and rankings for each workshop.Furthermore,post hoc testing was performed using the Spearman correlation coefficient,revealing a statistic value of 10.209,which validates the effectiveness and reliability of the proposed evaluation model.This model not only assists in identifying underperforming workshops within the factory but also provides solid data support and a decision-making basis for future energy efficiency optimization strategies.展开更多
The fatigue resistance and wear performance of aviation gears under extreme conditions(e.g.,high speed and heavy load)are closely related to tooth surface topography.Establishing an accurate correlation between surfac...The fatigue resistance and wear performance of aviation gears under extreme conditions(e.g.,high speed and heavy load)are closely related to tooth surface topography.Establishing an accurate correlation between surface topography and service performance requires numerous topography samples.Grinding-shot peening(GSP)combined processes are the key processes for manufacturing aviation gears.展开更多
基金Innovative Research Groups of the National Natural Science Foundation of China (No.51021004)National Science Foundation of China (No. 51079096)Program for New Century Excellent Talents in University (No. NCET-08-0391)
文摘A new back-analysis method of ground stress is proposed with comprehensive consideration of influence of topography, geology and nonlinear physical mechanical properties of rock on ground stress. This method based on non-uniform rational B-spline (NURBS) technology provides the means to build a refined three-dimensional finite element model with more accurate meshing under complex terrain and geological conditions. Meanwhile, this method is a back-analysis of ground stress with combination of multivariable linear regression model and neural network (ANN) model. Firstly, the regression model is used to fit approximately boundary loads. Regarding the regressed loads as mean value, some sets of boundary loads with the same interval are constructed according to the principle of orthogonal design, to calculate the corresponding ground stress at the observation positions using finite element method. The results (boundary loads and the corresponding ground stress) are added to the samples for ANN training. And on this basis, an ANN model is established to implement higher precise back-analysis of initial ground stress. A practical application case shows that the relative error between the inversed ground stress and observed value is mostly less than 10 %, which can meet the need of engineering design and construction requirements.
文摘A definition of combined phase center for horn feeds is given.Formulas of E-planeand H-plane combined phase center for conical horns and the corresponding Optimal model arepresented,and a fast optimization method for solving this model is described.By using thismethod,the phase center of corrugated horn is discussed and calculated,and the variation of thephase center with distance and operating frequency is given.
基金supported by the National Science and Technology Major Project during the 13th Five-Year Plan under grant(2016ZX05060-019)the National Science and Technology Major Project during the 13th Five-Year Plan under grant(2016ZX05060004).
文摘Existing“evaluation indicators”are selected and combined to build a model to support the optimization of shale gas horizontal wells.Towards this end,different“weighting methods”,including AHP and the so-called entropy method,are combined in the frame of the game theory.Using a relevant test case for the implementation of the model,it is shown that the horizontal section of the considered well is in the middle sweet spot area with good physical properties and fracturing ability.In comparison with the FSI(flow scanner Image)gas production profile,the new model seems to display better abilities for the optimization of horizontal wells.
基金supported by the National Natural Science Foundation of China(42377354)the Natural Science Foundation of Hubei province(2024AFB951)the Chunhui Plan Cooperation Research Project of the Chinese Ministry of Education(202200199).
文摘Soil erosion has been recognized as a critical environmental issue worldwide.While previous studies have primarily focused on watershed-scale soil erosion vulnerability from a natural factor perspective,there is a notable gap in understanding the intricate interplay between natural and socio-economic factors,especially in the context of spatial heterogeneity and nonlinear impacts of human-land interactions.To address this,our study evaluates the soil erosion vulnerability at a provincial scale,taking Hubei Province as a case study to explore the combined effects of natural and socio-economic factors.We developed an evaluation index system based on 15 indicators of soil erosion vulnerability:exposure,sensitivity,and adaptability.In addition,the combination weighting method was applied to determine index weights,and the spatial interaction was analyzed using spatial autocorrelation,geographical temporally weighted regression and geographical detector.The results showed an overall decreasing soil erosion intensity in Hubei Province during 2000 and 2020.The soil erosion vulnerability increased before 2000 and then.The areas with high soil erosion vulnerability were mainly confined in the central and southern regions of Hubei Province(Xiantao,Tianmen,Qianjiang and Ezhou)with obvious spatial aggregation that intensified over time.Natural factors(habitat quality index)had negative impacts on soil erosion vulnerability,whereas socio-economic factors(population density)showed substantial spatial variability in their influences.There was a positive correlation between soil erosion vulnerability and erosion intensity,with the correlation coefficients ranging from-0.41 and 0.93.The increase of slope was found to enhance the positive correlation between soil erosion vulnerability and intensity.
基金supported by the National Natural Science Foundation of China(52474018,52227804,U22B2072,52404012)the National Key Research and Development Program of China(2023YFC3009200)the Science Foundation of China University of Petroleum,Beijing(2462023BJRC008,2462024XKBH006)。
文摘Ultra-deep and complex formations are characterized by narrow safety density windows and challenging well control.The combined use of multiple well-killing methods or temporary adjustments to well-killing strategies is becoming common.However,conventional well-killing models often struggle to calculate the parameters required for these special cases.In this paper,a boundary matrix for wellkilling fluid density and volume is proposed to unify the driller's method,the engineer's method,and the weight-while-circulating method.Furthermore,a dynamic unified well-killing model is developed to enable the synergistic regulation of multiple well-killing methods.The model also can be applied with or without accounting for gas dissolution.Using this model,it is able to dynamically track key parameters during well killing and shut in the well at any time to determine the standpipe and casing pressures.The results indicate that the casing pressure drops to zero before the well-killing fluid returns to the annulus wellhead,and continued injection of the fluid leads to a gradual increase in standpipe pressure,a phenomenon not previously accounted for.The discrepancy between the actual and calculated standpipe/casing pressures after shut-in can be utilized to assess whether the downhole gas kick is effectively controlled.Through real-time adjustments to the boundary matrix,updated wellkilling parameters can be derived for conventional method,multi-method combination,temporary strategy modification,and other well-killing scenarios.The model was applied to two field wells under water-and oil-based drilling fluids.No secondary downhole complications occurred during well killing,and the calculated pressure curves closely matched the measured construction pressure curves,confirming the model's reliability and applicability.This study provides valuable theoretical guidance for enhancing well control safety in ultra-deep and complex formations.
基金financially supported by the National Key R&D Program of China(Grant No.2017YFC0405402)
文摘This paper proposes a structure combined by baffle and submerged breakwater （abbreviated to SCBSB in the following texts）. Such a combined structure is conducive to the water exchange in the harbor, and has strong capability on wave dissipation. Our paper focuses on the discussion of two typical structures, i.e., the submerged baffle and rectangular breakwater combined with the upper baffle respectively, which are named as SCBSB 1 and SCBSB2 for short. The eigenfunction method corrected by experimental results is used to investigate the wave dissipation characteristics. It shows that the calculated results agree well with the experimental data and the minimum value of the wave transmission coefficient can be obtained when the distance between the front and rear structures is from 1/4 to 1/2 of the incident wave length.
基金Project (59704004) supported by the National Natural Science Foundation of ChinaProject (2000) supported by Foundation for University Key Teacher by the Ministry of Education
文摘The pit limit optimization is discussed, which is one of the most important problems in the combined min-ing method, on the basis of the economic model of ore-blocks. A new principle of the limit optimization is put for-ward through analyzing the limitations of moving cone method under such conditions. With a view to recovering asmuch mineral resource as possible and making the maximum profit from the whole deposit, the new principle is tomaximize the sum of gain from both open-pit and underground mining. The mathematical models along the horizon-tal and vertical directions and modules for software package (DM&MCAD) have been developed and tested inTonglushan Copper Mine. It has been proved to be rather effective in the mining practice.
基金supported by the Health and Medical Research Fund(20190572)the Food and Health Bureau,The Government of the Hong Kong Special Administrative Region,General Research Fund(17122322 and 17126919)+9 种基金the Research Grants Council of the Hong Kong Special Administrative Region Government,NSFC Projects(T2122002,22077079,81871448)Ministry of Science and Technology of China Project(2022YFC2601700,2022YFF0710202)Shanghai Municipal Science and Technology Project(22Z510202478)Shanghai Jiao Tong University Projects(YG2021ZD19)Shanghai Municipal Health Commission Project(2019CXJQ03)Sanming Project of Medicine in Shenzhen,China(SZSM201911014)the High Level-Hospital Program,Health Commission of Guangdong Province,Chinathe research project of Hainan Academician Innovation Platform(YSPTZX202004)the University of Hong Kong Outstanding Young Researcher Awardand the University of Hong Kong Research Output Prize(Li Ka Shing Faculty of Medicine).
文摘Combinatorial drug therapies are generally more effective than monotherapies in treating viral infections.However,it is critical for dose optimization to maximize the efficacy and minimize side effects.Although various strategies have been devised to accelerate the optimization process,their efficiencies were limited by the high noises and suboptimal reproducibility of biological assays.With conventional methods,variances among the replications are used to evaluate the errors of the readouts alone rather than actively participating in the optimization.Herein,we present the Regression Modeling Enabled by Monte Carlo Method(ReMEMC)algorithm for rapid identification of effective combinational therapies.ReMEMC transforms the sample variations into probability distributions of the regression coefficients and predictions.In silico simulations revealed that ReMEMC outperformed conventional regression methods in benchmark problems,and demonstrated its superior robustness against experimental noises.Using COVID-19 as a model disease,ReMEMC successfully identified an optimal 3-drug combination among 10 anti-SARS-CoV-2 drug compounds within two rounds of experiments.The optimal combination showed 2-log and 3-log higher load reduction than non-optimized combinations and monotherapy,respectively.Further workflow refinement allowed identification of personalized drug combinational therapies within 5 days.The strategy may serve as an efficient and universal tool for dose combination optimization.
基金funded by the National Social Science Fund of China(Grant No.23BGL234).
文摘In the context of advancing towards dual carbon goals,numerous factories are actively engaging in energy efficiency upgrades and transformations.To accurately pinpoint energy efficiency bottlenecks within factories and prioritize renovation sequences,it is crucial to conduct comprehensive evaluations of the energy performance across various workshops.Therefore,this paper proposes an evaluation model for workshop energy efficiency based on the drive-state-response(DSR)framework combined with the fuzzy BORDA method.Firstly,an in-depth analysis of the relationships between different energy efficiency indicators was conducted.Based on the DSR model,evaluation criteria were selected from three dimensions-drive factors,state characteristics,and response measures-to establish a robust energy efficiency indicator system.Secondly,three distinct assessment techniques were selected:Grey Relational Analysis(GRA),Entropy Weight Method(EWM),and Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)forming a diversified set of evaluation methods.Subsequently,by introducing the fuzzy BORDA method,a comprehensive energy efficiency evaluation model was developed,aimed at quantitatively ranking the energy performance status of each workshop.Using a real-world factory as a case study,applying our proposed evaluationmodel yielded detailed scores and rankings for each workshop.Furthermore,post hoc testing was performed using the Spearman correlation coefficient,revealing a statistic value of 10.209,which validates the effectiveness and reliability of the proposed evaluation model.This model not only assists in identifying underperforming workshops within the factory but also provides solid data support and a decision-making basis for future energy efficiency optimization strategies.
基金supported by the National Natural Science Foundation of China(Grant No.U22B2086)。
文摘The fatigue resistance and wear performance of aviation gears under extreme conditions(e.g.,high speed and heavy load)are closely related to tooth surface topography.Establishing an accurate correlation between surface topography and service performance requires numerous topography samples.Grinding-shot peening(GSP)combined processes are the key processes for manufacturing aviation gears.
