This paper develops mathematically and empirically tractable regional and interregional model of economic devel-opment with increasing returns to scale (IRS) under the neoclassical assumptions. A one-sector, two-regio...This paper develops mathematically and empirically tractable regional and interregional model of economic devel-opment with increasing returns to scale (IRS) under the neoclassical assumptions. A one-sector, two-region model in which one region exhibits IRS is presented and the whole nation presents constant returns to scale. The development of the local IRS economy is shown to be constrained to a “moving equilibrium” path. The preliminary empirical results are sufficiently supportive of the argument to encourage further research along the lines of the model. In particular, the neoclassical model does not predict negative coefficients on the real rental value of capital in regressions explaining population or employment relative to that in the nation.展开更多
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
Decision-makers usually have an aspiration level,a target,or a benchmark they aim to achieve.This behavior can be rationalized within the expected utility framework,which incorporates the probability of success(achiev...Decision-makers usually have an aspiration level,a target,or a benchmark they aim to achieve.This behavior can be rationalized within the expected utility framework,which incorporates the probability of success(achieving the aspiration level)as an important aspect of decision-making.Motivated by these theories,this study defines the probability of success as the number of days a firm’s return outperformed its benchmark in the portfolio formation month.This study uses portfolio-level and firm-level analyses,revealing an economically substantial and statistically significant relationship between the probability of success and expected stock returns,even after controlling for common risk factors and various characteristics.Additional analyses support the behavioral theory of the firm,which posits that firms act to achieve short-term aspiration levels.展开更多
This paper proposes a new predictor by calculating the difference between the Japanese candlestick’s upper and lower shadows(ULD)constructed from CBOE volatility index(VIX)data.ULD is a powerful predictor for future ...This paper proposes a new predictor by calculating the difference between the Japanese candlestick’s upper and lower shadows(ULD)constructed from CBOE volatility index(VIX)data.ULD is a powerful predictor for future stock returns,and higher ULD leads to the subsequent decline of stock returns.Our results show that our new predictor generates R^2 values of up to 2.531%and 3.988%in-sample and out-of-sample,respectively;these values are much larger than the previous fundamental predictors.Moreover,the predictive information contained in ULD can help mean–variance investors achieve certainty equivalent return gains of as high as 327.1 basis points.Finally,the extension analysis and robustness tests indicate that recession is the primary cause of return predictability;our results are robust under different settings.展开更多
This study investigates the significance of e-commerce consumer opinions regarding value in China’s A-share market.By analyzing a large dataset comprising over 18 million online consumer reviews on JD.com,we demonstr...This study investigates the significance of e-commerce consumer opinions regarding value in China’s A-share market.By analyzing a large dataset comprising over 18 million online consumer reviews on JD.com,we demonstrate that sentiments expressed in e-commerce reviews can influence stock returns.This indicates that consumer opinions on the e-commerce platform contain valuable information that can impact the stock market.Our findings show that Consumer Negative Sentiment Tendency(CNST)and One-Star Tendency(OST)have a negative effect on expected stock returns,even after controlling for firm characteristics such as market risk,illiquidity,idiosyncratic volatility,and asset growth.Further analysis indicates that CNST demonstrates stronger predictive power within the home appliance industry,under high sentiment conditions,in growth companies,and among firms with lower accounting transparency.We also find that CNST negatively predicts revenue surprises,earnings surprises,and cash flow shocks.These results suggest that consumer opinions and sentiments derived from e-commerce reviews highlight firms’intrinsic worth and prospects.Future research could explore how firms,including suppliers and logistics companies,can leverage the information conveyed by consumer opinions on e-commerce platforms.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
我国每年生产大量的作物秸秆,不加处理或处理不当,会严重威胁水体或大气环境质量。秸秆还田是当前解决作物秸秆田间焚烧或无序堆放威胁环境质量的最主要方法。秸秆还田按目的可分为两种方式:以处置秸秆为目的的处置化原位还田和以消除...我国每年生产大量的作物秸秆,不加处理或处理不当,会严重威胁水体或大气环境质量。秸秆还田是当前解决作物秸秆田间焚烧或无序堆放威胁环境质量的最主要方法。秸秆还田按目的可分为两种方式:以处置秸秆为目的的处置化原位还田和以消除作物生长障碍因素为目的的消障化异地还田。无论何种秸秆还田方式均未利用秸秆生物能,虽在一定程度上可以提高土壤有机质含量,但作用有限,且无显著的时间累积效应。秸秆沼气化利用了秸秆生物能,但因产气不稳定,沼渣、沼液处理难等因素,推广应用难度大。笔者提出了一种能够在同一时间和空间,实现秸秆改土和产能等多重目标的秸秆处理方式,称作“秸秆改土产能时空一体化处理”方法(space-time Integration of Soil improvement and Energy production by using Straw,ISES),即就近集中秸秆于需要改良的土壤,使秸秆施用量达到5%土重以上,与土壤充分混匀,在淹水条件下,密封培养,收集厌氧发酵产生的沼气用作家庭燃料或作它用。ISES处理可跨肥力等级提升土壤有机质含量,产气量及气体中CH4浓度与沼气发酵相当,且不需要处理沼液和沼渣,可服务于改土、产能和固碳等多重目标。加强对ISES系统碳转化和CH4产生过程及其产气率和CH4浓度影响因素的研究,评估ISES处理过程及处理后的环境效应,对于优化处理工艺,明确可采用ISES处理的土壤类型、适宜的处理时间,降低ISES处理的环境效应,制订安全生产措施,预测经济可行性都是十分必要的。展开更多
基金Project (No. 362211) supported by the Social Science Foundation of Zhejiang Province, China
文摘This paper develops mathematically and empirically tractable regional and interregional model of economic devel-opment with increasing returns to scale (IRS) under the neoclassical assumptions. A one-sector, two-region model in which one region exhibits IRS is presented and the whole nation presents constant returns to scale. The development of the local IRS economy is shown to be constrained to a “moving equilibrium” path. The preliminary empirical results are sufficiently supportive of the argument to encourage further research along the lines of the model. In particular, the neoclassical model does not predict negative coefficients on the real rental value of capital in regressions explaining population or employment relative to that in the nation.
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.
文摘Decision-makers usually have an aspiration level,a target,or a benchmark they aim to achieve.This behavior can be rationalized within the expected utility framework,which incorporates the probability of success(achieving the aspiration level)as an important aspect of decision-making.Motivated by these theories,this study defines the probability of success as the number of days a firm’s return outperformed its benchmark in the portfolio formation month.This study uses portfolio-level and firm-level analyses,revealing an economically substantial and statistically significant relationship between the probability of success and expected stock returns,even after controlling for common risk factors and various characteristics.Additional analyses support the behavioral theory of the firm,which posits that firms act to achieve short-term aspiration levels.
基金supported by the National Natural Science Foundation of China granted:72131011Ministry of Education Humanities and Social Sciences Project granted:22YJA790011.
文摘This paper proposes a new predictor by calculating the difference between the Japanese candlestick’s upper and lower shadows(ULD)constructed from CBOE volatility index(VIX)data.ULD is a powerful predictor for future stock returns,and higher ULD leads to the subsequent decline of stock returns.Our results show that our new predictor generates R^2 values of up to 2.531%and 3.988%in-sample and out-of-sample,respectively;these values are much larger than the previous fundamental predictors.Moreover,the predictive information contained in ULD can help mean–variance investors achieve certainty equivalent return gains of as high as 327.1 basis points.Finally,the extension analysis and robustness tests indicate that recession is the primary cause of return predictability;our results are robust under different settings.
基金supported by the National Natural Science Foundation of China under projects No.62302319R&D Program of Beijing Municipal Education Commission(Grant No.KM202210038002).
文摘This study investigates the significance of e-commerce consumer opinions regarding value in China’s A-share market.By analyzing a large dataset comprising over 18 million online consumer reviews on JD.com,we demonstrate that sentiments expressed in e-commerce reviews can influence stock returns.This indicates that consumer opinions on the e-commerce platform contain valuable information that can impact the stock market.Our findings show that Consumer Negative Sentiment Tendency(CNST)and One-Star Tendency(OST)have a negative effect on expected stock returns,even after controlling for firm characteristics such as market risk,illiquidity,idiosyncratic volatility,and asset growth.Further analysis indicates that CNST demonstrates stronger predictive power within the home appliance industry,under high sentiment conditions,in growth companies,and among firms with lower accounting transparency.We also find that CNST negatively predicts revenue surprises,earnings surprises,and cash flow shocks.These results suggest that consumer opinions and sentiments derived from e-commerce reviews highlight firms’intrinsic worth and prospects.Future research could explore how firms,including suppliers and logistics companies,can leverage the information conveyed by consumer opinions on e-commerce platforms.
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.
文摘我国每年生产大量的作物秸秆,不加处理或处理不当,会严重威胁水体或大气环境质量。秸秆还田是当前解决作物秸秆田间焚烧或无序堆放威胁环境质量的最主要方法。秸秆还田按目的可分为两种方式:以处置秸秆为目的的处置化原位还田和以消除作物生长障碍因素为目的的消障化异地还田。无论何种秸秆还田方式均未利用秸秆生物能,虽在一定程度上可以提高土壤有机质含量,但作用有限,且无显著的时间累积效应。秸秆沼气化利用了秸秆生物能,但因产气不稳定,沼渣、沼液处理难等因素,推广应用难度大。笔者提出了一种能够在同一时间和空间,实现秸秆改土和产能等多重目标的秸秆处理方式,称作“秸秆改土产能时空一体化处理”方法(space-time Integration of Soil improvement and Energy production by using Straw,ISES),即就近集中秸秆于需要改良的土壤,使秸秆施用量达到5%土重以上,与土壤充分混匀,在淹水条件下,密封培养,收集厌氧发酵产生的沼气用作家庭燃料或作它用。ISES处理可跨肥力等级提升土壤有机质含量,产气量及气体中CH4浓度与沼气发酵相当,且不需要处理沼液和沼渣,可服务于改土、产能和固碳等多重目标。加强对ISES系统碳转化和CH4产生过程及其产气率和CH4浓度影响因素的研究,评估ISES处理过程及处理后的环境效应,对于优化处理工艺,明确可采用ISES处理的土壤类型、适宜的处理时间,降低ISES处理的环境效应,制订安全生产措施,预测经济可行性都是十分必要的。
