Key technologies that make productivity increase are revealed through analyzing the best practices and production data in major shale basins of North America.Trends of the key technologies and optimization designs for...Key technologies that make productivity increase are revealed through analyzing the best practices and production data in major shale basins of North America.Trends of the key technologies and optimization designs for shale oil and gas development are summarized and analyzed based on drilling and completion operations and well data.These technologies mainly include:(1)Optimizing well design and hydraulic fracturing design,including reducing cluster spacing,increasing proppant and fracturing fluid volumes,optimizing horizontal well lateral length and fracture stage length.The most effective method is to reduce cluster spacing to an optimized length.The second most effective method is to optimally increase proppant volumes.(2)Placing horizontal wells in the sweet spots and drilling the wells parallel or close to the minimum horizontal stress direction.(3)Using cube development with optimized well spacing to maximize resource recovery and reduce well interferences.Plus,in-situ stress impacts on hydraulic fracture propagation and hydrocarbon production are addressed.Determination of formation breakdown pressure is studied by considering the impacts of in-situ stresses,drilling and perforation directions.Whether or not the hydraulic fracturing can generate orthogonal fracture networks is also discussed.The key technologies and optimization design parameters proposed in this paper can be applied to guide new well placement,drilling and completion designs,and hydraulic fracture operations to increase productivity.展开更多
In the traditional blast furnace(BF)ironmaking process in China,a notable deviation exists between the theoretical and actual yield of hot metal,leading to unexpected iron loss and restricting the improvement of produ...In the traditional blast furnace(BF)ironmaking process in China,a notable deviation exists between the theoretical and actual yield of hot metal,leading to unexpected iron loss and restricting the improvement of production capacity,which cannot adapt to the increasingly intensified smelting rhythm.Focusing on a BF in a Chinese steel enterprise,a deep neural network algorithm was designed to model the impact of multiple parameters on actual yield of hot metal in a single BF smelting cycle,successfully accomplishing the theoretical computation and real-time prediction of yield of hot metal for subsequent,unknown BF smelting cycle.Test results show that the proposed algorithm demonstrates an impressive prediction accuracy of 86.7% within an error range of±10 t and can swiftly complete the training and convergence process in 32.5 s.By integrating prediction results with Nomogram,a regulatory mechanism was engineered to minimize the deviation between theoretical and actual yield of hot metal.This mechanism ensures the yield enhancement of hot metal through dynamic adjustments of BF operational parameters.Industrial-scale application experiments confirmed that the intelligent operation and optimization system,developed in the laboratory,can maintain the yield deviation of hot metal within a stable range of 30 t,achieving a maximum reduction in iron loss rate of 17.65%compared to that before system operation.The findings provide robust support for the yield increase and efficiency improvement of the experimental BF.展开更多
In the context of the prevalent winter air quality issues in China marked by declining PM_(2.5)and rising O_(3),this study employed amodified WRF-Chem model to examine the aerosol radiation interaction(ARI),heterogene...In the context of the prevalent winter air quality issues in China marked by declining PM_(2.5)and rising O_(3),this study employed amodified WRF-Chem model to examine the aerosol radiation interaction(ARI),heterogeneous chemistry(AHC),and their combined impact(ALL)on the variations in O_(3)and PM_(2.5)during the 2014–2020 in eastern China.Our analysis confirmed that ARI curtailed O_(3)while elevating PM_(2.5).AHC reduced O_(3)through heterogeneous absorption of NOx and hydroxideswhile notably fostering fine-grained sulfate,resulting in a PM_(2.5)increase.Emission reductions mitigated the inhibitory impact of ARI on meteorological fields and photolysis rates.Emission reduction individually without aerosol feedback led to a 5.43 ppb O_(3)increase and a 22.89μg/m^(3)PM_(2.5)decrease.ARI and AHC amplified the emission-reduction-induced(ERI)O_(3)rise by 1.83 and 0.31 ppb,respectively.The response of ARI to emission diminution brought about a modest PM_(2.5)increase of 0.31μg/m^(3).Conversely,AHC,acting as the primary contributor,caused a noteworthy PM_(2.5)decrease of 4.60μg/m^(3).As efforts concentrate on reducing PM_(2.5),the promotion of ARI on PM_(2.5)counterbalanced the efficacy of emission reduction and the AHC-induced strengthening of PM_(2.5)decrease.The ALL magnified the ERI O_(3)increase by 38.9%and PM_(2.5)decrease by 18.7%.Sensitivity experiments with different degrees of emission reduction demonstrated a consistent linear relationship between the ALL-induced enhancement of O_(3)increase and PM_(2.5)decrease to the ERI PM_(2.5)decline.Our investigation revealed the complex connection between emissions and aerosol feedback in influencing air quality.展开更多
The goal of this paper is to investigate the theory of Noether solvability for Volterra singular integral equations(VSIEs)with convolution and Cauchy kernels in a more general function class.To obtain the analytic sol...The goal of this paper is to investigate the theory of Noether solvability for Volterra singular integral equations(VSIEs)with convolution and Cauchy kernels in a more general function class.To obtain the analytic solutions,we transform such equations into boundary value problems with discontinuous coefficients by the properties of Fourier analysis.In view of the analytical Riemann-Hilbert method,the generalized Liouville theorem and Sokhotski-Plemelj formula,we get the uniqueness and existence of solutions for such problems,and study the asymptotic property of solutions at nodes.Therefore,this paper improves the theory of singular integral equations and boundary value problems.展开更多
After insufflating extended endophytes phomopsis B3 ferment diluent on seedling bed of rice, the effect of microbial inoculum on rice growth was studied. The investigation result of seedlings before transplanting seed...After insufflating extended endophytes phomopsis B3 ferment diluent on seedling bed of rice, the effect of microbial inoculum on rice growth was studied. The investigation result of seedlings before transplanting seedling showed that leaf age,the number of green leaves,the number of tiller of individual plant and the weight of per 100 fresh plants in microbial inoculum treatment group increased 0.11,0.12 ,0. 03 and 2.6 g respectively compared with those of control group. 20 days after transplanting, increased tiller number in microbial inoculum treatment group was 55 500 hm^2 more than that in control group. 30 days after transplanting, tiller number in microbial inoculum treatment group was 42 000 hm^2 more than that in control group. In harvest season, the yield ,weight of I 0130 grain and seed-setting rate increased 300 kg/hm2, 0. 7 g and 0. 23% respectively compared with these in control group. The result of preliminary study demonstrated that microbial inoculum confected by endophytes phomopsis B3 could increase the number of strong seedling and yield.展开更多
The construction controlling elements,including construction performance at low ambient temperatures,reserved time ranges,and the strength increasing rule,for locally developed epoxy asphalt mixture（LDEAM） are studi...The construction controlling elements,including construction performance at low ambient temperatures,reserved time ranges,and the strength increasing rule,for locally developed epoxy asphalt mixture（LDEAM） are studied through laboratory tests.Air void and Marshall stability are chosen as the performance measures for evaluating the construction quality.The wheel rolling test is used to simulate the actual construction situations,while the Marshall test and the Brookfield viscosity test are adopted to study the strength increasing rule.The experimental results reveal that the LDEAM can be constructed under a low ambient temperature condition of 10℃,and its longest reserved time is 70 min at a reserved temperature of 120℃.Test also shows that the strength of the LDEAM increases with time and temperature before cured.Finally,the theoretical reason for the strength increasing rule is analyzed on the basis of the organic chemistry theory.展开更多
The number and diversity of inhibitory neurons(INs)increased substantially during mammalian brain evolution.However,the generative mechanisms of the vast repertoire of human INs remain elusive.We performed spatial and...The number and diversity of inhibitory neurons(INs)increased substantially during mammalian brain evolution.However,the generative mechanisms of the vast repertoire of human INs remain elusive.We performed spatial and single-cell transcriptomics of human medial ganglionic eminence(hMGE),a pivotal source of cortical and subpallial INs,and built the trajectories of hMGE-derived cells during brain development.We identified spatiotemporally and molecularly segregated progenitor cell populations fated to produce distinct IN types.展开更多
AIM:To comprehensively investigate the relationship between outer retinal layer thickness and age in normal eyes.METHODS:One hundred normal eyes of 100 subjects who underwent spectral-domain optical coherence tomograp...AIM:To comprehensively investigate the relationship between outer retinal layer thickness and age in normal eyes.METHODS:One hundred normal eyes of 100 subjects who underwent spectral-domain optical coherence tomography(SD-OCT)were included in this retrospective study.The distances between the external limiting membrane(ELM)line and the photoreceptor inner segment/outer segment(IS/OS)line(ELM-IS/OS),the IS/OS line and the cone outer segment tips(COST)line(IS/OS-COST),the COST line and the retinal pigment epithelium(RPE)complex(COST-RPE)and the full retinal thickness(RT)were measured at the fovea and on four quarters.The relationship between thickness and age or sex was then analysed.RESULTS:A thinner RT was observed in women in a multiple regression analysis(men:234.47±16.79μm;women:223.13±15.43μm).The RT on the nasal quarter and the ELM-IS/OS thickness at the fovea and on the four quarters were significantly and negatively correlated with age.The IS/OS-COST and COST-RPE thicknesses at the fovea and on the four quarters were not significantly correlated with age or sex,respectively.The RT at the fovea was significantly thinner than on the four quarters.The ELM-IS/OS,IS/OS-COST and COST-RPE thicknesses at the fovea were significantly thicker than on the four quarters.CONCLUSION:In normal eyes,the RT thickness on the nasal quarter and the ELM-IS/OS thickness were significantly and negatively correlated with age.The IS/OS-COST and COST-RPE thicknesses were not significantly correlated with age or sex.展开更多
The dual random models about the life insurance and social pension insurance have received considerable attention in the recent articles on actuarial theory and applications. This paper discusses a general kind of inc...The dual random models about the life insurance and social pension insurance have received considerable attention in the recent articles on actuarial theory and applications. This paper discusses a general kind of increasing annuity based on its force of interest accumulation function as a general random process. The dual random model of the present value of the benefits of the increasing annuity has been set, and their moments have been calculated under certain conditions.展开更多
The response of non-uniformity of precipitation extremes over China to doubled CO2has been analyzed using the daily precipitation simulated by a coupled general circulation model,MIROC_Hires.The major conclusions are ...The response of non-uniformity of precipitation extremes over China to doubled CO2has been analyzed using the daily precipitation simulated by a coupled general circulation model,MIROC_Hires.The major conclusions are as follows:under the CO2increasing scenario(SRES A1B),the climatological precipitation extremes are concentrated over the southern China,while they are uniformly distributed over the northern China.For interannual variability,the concentration of precipitation extremes is small over the southern China,but it is opposite over the northern China.The warming effects on the horizontal and vertical scales are different over the northern and southern part of China.Furthermore,the atmospheric stability is also different between the two parts of China.The heterogeneous warming is one of the possible reasons for the changes in non-uniformity of precipitation extremes over China.展开更多
文摘Key technologies that make productivity increase are revealed through analyzing the best practices and production data in major shale basins of North America.Trends of the key technologies and optimization designs for shale oil and gas development are summarized and analyzed based on drilling and completion operations and well data.These technologies mainly include:(1)Optimizing well design and hydraulic fracturing design,including reducing cluster spacing,increasing proppant and fracturing fluid volumes,optimizing horizontal well lateral length and fracture stage length.The most effective method is to reduce cluster spacing to an optimized length.The second most effective method is to optimally increase proppant volumes.(2)Placing horizontal wells in the sweet spots and drilling the wells parallel or close to the minimum horizontal stress direction.(3)Using cube development with optimized well spacing to maximize resource recovery and reduce well interferences.Plus,in-situ stress impacts on hydraulic fracture propagation and hydrocarbon production are addressed.Determination of formation breakdown pressure is studied by considering the impacts of in-situ stresses,drilling and perforation directions.Whether or not the hydraulic fracturing can generate orthogonal fracture networks is also discussed.The key technologies and optimization design parameters proposed in this paper can be applied to guide new well placement,drilling and completion designs,and hydraulic fracture operations to increase productivity.
基金the financial supports from the National Natural Science Foundation of China(52004096)Natural Science Foundation of Hebei Province(E2024209101)+2 种基金Hebei Province Science and Technology R&D Platform Construction Project(23560301D)Tangshan Science and Technology Bureau Project(23130202E)Graduate Student Innovation Fund of North China University of Science and Technology(CXZZBS2025150).
文摘In the traditional blast furnace(BF)ironmaking process in China,a notable deviation exists between the theoretical and actual yield of hot metal,leading to unexpected iron loss and restricting the improvement of production capacity,which cannot adapt to the increasingly intensified smelting rhythm.Focusing on a BF in a Chinese steel enterprise,a deep neural network algorithm was designed to model the impact of multiple parameters on actual yield of hot metal in a single BF smelting cycle,successfully accomplishing the theoretical computation and real-time prediction of yield of hot metal for subsequent,unknown BF smelting cycle.Test results show that the proposed algorithm demonstrates an impressive prediction accuracy of 86.7% within an error range of±10 t and can swiftly complete the training and convergence process in 32.5 s.By integrating prediction results with Nomogram,a regulatory mechanism was engineered to minimize the deviation between theoretical and actual yield of hot metal.This mechanism ensures the yield enhancement of hot metal through dynamic adjustments of BF operational parameters.Industrial-scale application experiments confirmed that the intelligent operation and optimization system,developed in the laboratory,can maintain the yield deviation of hot metal within a stable range of 30 t,achieving a maximum reduction in iron loss rate of 17.65%compared to that before system operation.The findings provide robust support for the yield increase and efficiency improvement of the experimental BF.
基金supported by the National Natural Science Foundation of China(No.42077192)the National Key Basic Research&Development Program of China(No.2020YFA0607802).
文摘In the context of the prevalent winter air quality issues in China marked by declining PM_(2.5)and rising O_(3),this study employed amodified WRF-Chem model to examine the aerosol radiation interaction(ARI),heterogeneous chemistry(AHC),and their combined impact(ALL)on the variations in O_(3)and PM_(2.5)during the 2014–2020 in eastern China.Our analysis confirmed that ARI curtailed O_(3)while elevating PM_(2.5).AHC reduced O_(3)through heterogeneous absorption of NOx and hydroxideswhile notably fostering fine-grained sulfate,resulting in a PM_(2.5)increase.Emission reductions mitigated the inhibitory impact of ARI on meteorological fields and photolysis rates.Emission reduction individually without aerosol feedback led to a 5.43 ppb O_(3)increase and a 22.89μg/m^(3)PM_(2.5)decrease.ARI and AHC amplified the emission-reduction-induced(ERI)O_(3)rise by 1.83 and 0.31 ppb,respectively.The response of ARI to emission diminution brought about a modest PM_(2.5)increase of 0.31μg/m^(3).Conversely,AHC,acting as the primary contributor,caused a noteworthy PM_(2.5)decrease of 4.60μg/m^(3).As efforts concentrate on reducing PM_(2.5),the promotion of ARI on PM_(2.5)counterbalanced the efficacy of emission reduction and the AHC-induced strengthening of PM_(2.5)decrease.The ALL magnified the ERI O_(3)increase by 38.9%and PM_(2.5)decrease by 18.7%.Sensitivity experiments with different degrees of emission reduction demonstrated a consistent linear relationship between the ALL-induced enhancement of O_(3)increase and PM_(2.5)decrease to the ERI PM_(2.5)decline.Our investigation revealed the complex connection between emissions and aerosol feedback in influencing air quality.
基金Supported by National Natural Science Foundation of China(Grant No.11971015).
文摘The goal of this paper is to investigate the theory of Noether solvability for Volterra singular integral equations(VSIEs)with convolution and Cauchy kernels in a more general function class.To obtain the analytic solutions,we transform such equations into boundary value problems with discontinuous coefficients by the properties of Fourier analysis.In view of the analytical Riemann-Hilbert method,the generalized Liouville theorem and Sokhotski-Plemelj formula,we get the uniqueness and existence of solutions for such problems,and study the asymptotic property of solutions at nodes.Therefore,this paper improves the theory of singular integral equations and boundary value problems.
基金Supported by the National Natural Science Foundation of China(30770073,30500066)~~
文摘After insufflating extended endophytes phomopsis B3 ferment diluent on seedling bed of rice, the effect of microbial inoculum on rice growth was studied. The investigation result of seedlings before transplanting seedling showed that leaf age,the number of green leaves,the number of tiller of individual plant and the weight of per 100 fresh plants in microbial inoculum treatment group increased 0.11,0.12 ,0. 03 and 2.6 g respectively compared with those of control group. 20 days after transplanting, increased tiller number in microbial inoculum treatment group was 55 500 hm^2 more than that in control group. 30 days after transplanting, tiller number in microbial inoculum treatment group was 42 000 hm^2 more than that in control group. In harvest season, the yield ,weight of I 0130 grain and seed-setting rate increased 300 kg/hm2, 0. 7 g and 0. 23% respectively compared with these in control group. The result of preliminary study demonstrated that microbial inoculum confected by endophytes phomopsis B3 could increase the number of strong seedling and yield.
基金The National Natural Science Foundation of China (No.50578038)the National Key Technology R& D Program of China during the 11th Five-Year Plan Period (No. 2009BAG15B03)
文摘The construction controlling elements,including construction performance at low ambient temperatures,reserved time ranges,and the strength increasing rule,for locally developed epoxy asphalt mixture（LDEAM） are studied through laboratory tests.Air void and Marshall stability are chosen as the performance measures for evaluating the construction quality.The wheel rolling test is used to simulate the actual construction situations,while the Marshall test and the Brookfield viscosity test are adopted to study the strength increasing rule.The experimental results reveal that the LDEAM can be constructed under a low ambient temperature condition of 10℃,and its longest reserved time is 70 min at a reserved temperature of 120℃.Test also shows that the strength of the LDEAM increases with time and temperature before cured.Finally,the theoretical reason for the strength increasing rule is analyzed on the basis of the organic chemistry theory.
文摘The number and diversity of inhibitory neurons(INs)increased substantially during mammalian brain evolution.However,the generative mechanisms of the vast repertoire of human INs remain elusive.We performed spatial and single-cell transcriptomics of human medial ganglionic eminence(hMGE),a pivotal source of cortical and subpallial INs,and built the trajectories of hMGE-derived cells during brain development.We identified spatiotemporally and molecularly segregated progenitor cell populations fated to produce distinct IN types.
文摘AIM:To comprehensively investigate the relationship between outer retinal layer thickness and age in normal eyes.METHODS:One hundred normal eyes of 100 subjects who underwent spectral-domain optical coherence tomography(SD-OCT)were included in this retrospective study.The distances between the external limiting membrane(ELM)line and the photoreceptor inner segment/outer segment(IS/OS)line(ELM-IS/OS),the IS/OS line and the cone outer segment tips(COST)line(IS/OS-COST),the COST line and the retinal pigment epithelium(RPE)complex(COST-RPE)and the full retinal thickness(RT)were measured at the fovea and on four quarters.The relationship between thickness and age or sex was then analysed.RESULTS:A thinner RT was observed in women in a multiple regression analysis(men:234.47±16.79μm;women:223.13±15.43μm).The RT on the nasal quarter and the ELM-IS/OS thickness at the fovea and on the four quarters were significantly and negatively correlated with age.The IS/OS-COST and COST-RPE thicknesses at the fovea and on the four quarters were not significantly correlated with age or sex,respectively.The RT at the fovea was significantly thinner than on the four quarters.The ELM-IS/OS,IS/OS-COST and COST-RPE thicknesses at the fovea were significantly thicker than on the four quarters.CONCLUSION:In normal eyes,the RT thickness on the nasal quarter and the ELM-IS/OS thickness were significantly and negatively correlated with age.The IS/OS-COST and COST-RPE thicknesses were not significantly correlated with age or sex.
文摘The dual random models about the life insurance and social pension insurance have received considerable attention in the recent articles on actuarial theory and applications. This paper discusses a general kind of increasing annuity based on its force of interest accumulation function as a general random process. The dual random model of the present value of the benefits of the increasing annuity has been set, and their moments have been calculated under certain conditions.
基金National Basic Research Program of China(973 Program,2012CB955901)National Natural Science Foundation of China(51190090)+3 种基金National Natural Science Foundation of China(41105044,41205038)Open Project Program of State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment(SKLLQG1308)Key Laboratory of Meteorological Disaster of Ministry of Education,Nanjing University of Information Science and Technology(KLME1201)Fundamental Research Funds for the Central Universitites(2012B00114)
文摘The response of non-uniformity of precipitation extremes over China to doubled CO2has been analyzed using the daily precipitation simulated by a coupled general circulation model,MIROC_Hires.The major conclusions are as follows:under the CO2increasing scenario(SRES A1B),the climatological precipitation extremes are concentrated over the southern China,while they are uniformly distributed over the northern China.For interannual variability,the concentration of precipitation extremes is small over the southern China,but it is opposite over the northern China.The warming effects on the horizontal and vertical scales are different over the northern and southern part of China.Furthermore,the atmospheric stability is also different between the two parts of China.The heterogeneous warming is one of the possible reasons for the changes in non-uniformity of precipitation extremes over China.
