A class of cubic trigonometric interpolation spline curves with two parameters is presented in this paper. The spline curves can automatically interpolate the given data points and become C^2 interpolation curves with...A class of cubic trigonometric interpolation spline curves with two parameters is presented in this paper. The spline curves can automatically interpolate the given data points and become C^2 interpolation curves without solving equations system even if the interpolation conditions are fixed. Moreover, shape of the interpolation spline curves can be globally adjusted by the two parameters. By selecting proper values of the two parameters,the optimal interpolation spline curves can be obtained.展开更多
Recovering the iron(Fe)and phosphorus(P)contained in steelmaking slags not only reduces the environmental burden caused by the accumulated slag,but also is the way to develop a circular economy and achieve sustainable...Recovering the iron(Fe)and phosphorus(P)contained in steelmaking slags not only reduces the environmental burden caused by the accumulated slag,but also is the way to develop a circular economy and achieve sustainable development in the steel industry.We had pre-viously found the possibility of recovering Fe and P resources,i.e.,magnetite(Fe_(3)O_(4)) and calcium phosphate(Ca_(10)P_(6)O_(25)),contained in steel-making slags by adjusting oxygen partial pressure and adding modifier B_(2)O_(3).As a fundamental study for efficiently recovering Fe and P from steelmaking slag,in this study,the crystallization behavior of the CaO-SiO_(2)-FeO-P_(2)O_(5)-B_(2)O_(3) melt has been observed in situ,using a confocal scanning laser microscope(CLSM).The kinetics of nucleation and growth of Fe-and P-rich phases have been calculated using a classical crys-tallization kinetic theory.During cooling,a Fe_(3)O_(4) phase with faceted morphology was observed as the 1st precipitated phase in the isothermal interval of 1300-1150℃,while Ca_(10)P_(6)O_(25),with rod-shaped morphology,was found to be the 2nd phase to precipitate in the interval of 1150-1000℃.The crystallization abilities of Fe_(3)O_(4) and Ca_(10)P_(6)O_(25) phases in the CaO-SiO_(2)-FeO-P_(2)O_(5)-B_(2)O_(3) melt were quantified with the in-dex of(T_(U)−T_(I))/T_(I)(where T_(I) represents the peak temperature of the nucleation rate and TU stands for that of growth rate),and the crystalliza-tion ability of Fe_(3)O_(4) was found to be larger than that of Ca_(10)P_(6)O_(25) phase.The range of crystallization temperature for Fe_(3)O_(4) and Ca_(10)P_(6)O_(25) phases was optimized subsequently.The Fe_(3)O_(4) and Ca_(10)P_(6)O_(25) phases are the potential sources for ferrous feedstock and phosphate fertilizer,respectively.展开更多
The clustered,regularly interspaced,short palindromic repeat associated endonuclease 9(CRISPR/Cas9)system has emerged as a powerful approach for precision breeding to create plants with desirable traits.However,the CR...The clustered,regularly interspaced,short palindromic repeat associated endonuclease 9(CRISPR/Cas9)system has emerged as a powerful approach for precision breeding to create plants with desirable traits.However,the CRISPR/Cas9 system relies heavily on an efficient plant transformation system that is usually time-consuming and costly.Here,we have constructed a CRISPR-Cas9 vector with neomycin phosphotransferase II and green fluorescent protein(eGFP-NPTII),where the high expression of GFP during plant regeneration allowed us to minimize the positional effect on T-DNA expression and facilitate screening T-DNA-free mutants.Successful gene editing using CRISPR/Cas9 has been illustrated in different plant species,but an important aesthetic characteristic of leaf variegation remained unexplored.With the newly designed construct,we have targeted the variegation gene LsVAR2 in lettuce.Our results indicated that LsVAR2 is closely related to both AtFtsH2 and AtFtsH8,in which homozygous mutations lead to an albino phenotype while a variegated phenotype was induced by CRISPR/Cas9 de novo gene editing.In conclusion,the unique design of our CRISPR/Cas9 construct could efficiently edit the target gene and ease the screening of non-TDNA mutants through detecting GFP signals during plant regeneration and progeny segregation.Additionally,the success of gene-editing of LsVAR2 in lettuce demonstrates proof in this method to develop novel plant breeding materials for valuable horticultural plant species.展开更多
Using data on firms listed on Chinese A-share markets from 2009 to 2017,this paperapplies the difference-in-difference model to test the effect of trade facilitation onpreventing the formation of zombie firms.We find ...Using data on firms listed on Chinese A-share markets from 2009 to 2017,this paperapplies the difference-in-difference model to test the effect of trade facilitation onpreventing the formation of zombie firms.We find that the China Railway Express(CRE)significantly prevented the formation of such firms.Mechanism tests show:(i)the CRE has accelerated the speed of sales,which increased the overseas salesrevenue of firms;(ii)the economies of scale and the capital accumulation effectcaused by the CRE can help increase firms'solvency and development ability.Heterogeneity analysis indicates that the effect of the CRE on preventing theformation of zombie firms is mainly reflected in non-state-owned firms,firms inhighly competitive industries,and firms in the eastern region of China.We suggestthat China should continue to promote trade facilitation by expanding the CRE andstrengthening the market's dominant role in preventing the formation of zombie firms.Disadvantaged firms should seize the development opportunities brought by the CRE.展开更多
Fast and accurate MRI reconstruction is a key concern in modern clinical practice.Recently,numerous Deep-Learning methods have been proposed for MRI reconstruction,however,they usually fail to reconstruct sharp detail...Fast and accurate MRI reconstruction is a key concern in modern clinical practice.Recently,numerous Deep-Learning methods have been proposed for MRI reconstruction,however,they usually fail to reconstruct sharp details from the subsampled k-space data.To solve this problem,we propose a lightweight and accurate Edge Attention MRI Reconstruction Network(EAMRI)to reconstruct images with edge guidance.Specifically,we design an efficient Edge Prediction Network to directly predict accurate edges from the blurred image.Meanwhile,we propose a novel Edge Attention Module(EAM)to guide the image reconstruction utilizing the extracted edge priors,as inspired by the popular self-attention mechanism.EAM first projects the input image and edges into Q_(image),K_(edge),and V_(image),respectively.Then EAM pairs the Q_(image)with K_(edge)along the channel dimension,such that 1)it can search globally for the high-frequency image features that are activated by the edge priors;2)the overall computation burdens are largely reduced compared with the traditional spatial-wise attention.With the help of EAM,the predicted edge priors can effectively guide the model to reconstruct high-quality MR images with accurate edges.Extensive experiments show that our proposed EAMRI outperforms other methods with fewer parameters and can recover more accurate edges.展开更多
This study uses the difference-in differences method to test the impact of a high-speed rail(HSR)service on the issuance of municipal corporate bonds(MCB)based on panel data for prefecture-level cities in China from 2...This study uses the difference-in differences method to test the impact of a high-speed rail(HSR)service on the issuance of municipal corporate bonds(MCB)based on panel data for prefecture-level cities in China from 2003 to 2016.The study has three findings.First,HSR increased the scale of the issuance of MCB significantly.After conducting a series of robustness tests,the above conclusion remained robust.Second,HSR affected the issuance of MCB by increasing the city's financing demands and improving the city's financing capacity.Third,the effect of HSR on the issuance of MCB varied from city to city.Specifically,the promotion of the opening of HSR to the issuance of MCB was concentrated in remote and fast growing cities.High-speed rail can also effectively reduce the cost and shrink credit spreads of the MCB.This paper shows that it is necessary to further optimize the layout of HSR,release and exploit the financial resource reallocation effect of HSR,and provide financial support to the high-quality development of cities.展开更多
基金supported by the National Natural Science Foundation of China(11171181)the Scientific Research Fund of Hunan Provincial Education Department of China(14B099)
文摘A class of cubic trigonometric interpolation spline curves with two parameters is presented in this paper. The spline curves can automatically interpolate the given data points and become C^2 interpolation curves without solving equations system even if the interpolation conditions are fixed. Moreover, shape of the interpolation spline curves can be globally adjusted by the two parameters. By selecting proper values of the two parameters,the optimal interpolation spline curves can be obtained.
基金supported by Jiangsu University(No.19JDG011)the Project of the National Natural Science Foundation of China(Nos.51874272,52111540265)the Open Foundation of State Key Laboratory of Mineral Processing(No.BGRIMM-KJSKL-2022-23).
文摘Recovering the iron(Fe)and phosphorus(P)contained in steelmaking slags not only reduces the environmental burden caused by the accumulated slag,but also is the way to develop a circular economy and achieve sustainable development in the steel industry.We had pre-viously found the possibility of recovering Fe and P resources,i.e.,magnetite(Fe_(3)O_(4)) and calcium phosphate(Ca_(10)P_(6)O_(25)),contained in steel-making slags by adjusting oxygen partial pressure and adding modifier B_(2)O_(3).As a fundamental study for efficiently recovering Fe and P from steelmaking slag,in this study,the crystallization behavior of the CaO-SiO_(2)-FeO-P_(2)O_(5)-B_(2)O_(3) melt has been observed in situ,using a confocal scanning laser microscope(CLSM).The kinetics of nucleation and growth of Fe-and P-rich phases have been calculated using a classical crys-tallization kinetic theory.During cooling,a Fe_(3)O_(4) phase with faceted morphology was observed as the 1st precipitated phase in the isothermal interval of 1300-1150℃,while Ca_(10)P_(6)O_(25),with rod-shaped morphology,was found to be the 2nd phase to precipitate in the interval of 1150-1000℃.The crystallization abilities of Fe_(3)O_(4) and Ca_(10)P_(6)O_(25) phases in the CaO-SiO_(2)-FeO-P_(2)O_(5)-B_(2)O_(3) melt were quantified with the in-dex of(T_(U)−T_(I))/T_(I)(where T_(I) represents the peak temperature of the nucleation rate and TU stands for that of growth rate),and the crystalliza-tion ability of Fe_(3)O_(4) was found to be larger than that of Ca_(10)P_(6)O_(25) phase.The range of crystallization temperature for Fe_(3)O_(4) and Ca_(10)P_(6)O_(25) phases was optimized subsequently.The Fe_(3)O_(4) and Ca_(10)P_(6)O_(25) phases are the potential sources for ferrous feedstock and phosphate fertilizer,respectively.
基金This project has been sponsored by the USDA-NIFA GRANT12683186。
文摘The clustered,regularly interspaced,short palindromic repeat associated endonuclease 9(CRISPR/Cas9)system has emerged as a powerful approach for precision breeding to create plants with desirable traits.However,the CRISPR/Cas9 system relies heavily on an efficient plant transformation system that is usually time-consuming and costly.Here,we have constructed a CRISPR-Cas9 vector with neomycin phosphotransferase II and green fluorescent protein(eGFP-NPTII),where the high expression of GFP during plant regeneration allowed us to minimize the positional effect on T-DNA expression and facilitate screening T-DNA-free mutants.Successful gene editing using CRISPR/Cas9 has been illustrated in different plant species,but an important aesthetic characteristic of leaf variegation remained unexplored.With the newly designed construct,we have targeted the variegation gene LsVAR2 in lettuce.Our results indicated that LsVAR2 is closely related to both AtFtsH2 and AtFtsH8,in which homozygous mutations lead to an albino phenotype while a variegated phenotype was induced by CRISPR/Cas9 de novo gene editing.In conclusion,the unique design of our CRISPR/Cas9 construct could efficiently edit the target gene and ease the screening of non-TDNA mutants through detecting GFP signals during plant regeneration and progeny segregation.Additionally,the success of gene-editing of LsVAR2 in lettuce demonstrates proof in this method to develop novel plant breeding materials for valuable horticultural plant species.
基金the support from the National Natural Science Foundation of China(No.71902050).
文摘Using data on firms listed on Chinese A-share markets from 2009 to 2017,this paperapplies the difference-in-difference model to test the effect of trade facilitation onpreventing the formation of zombie firms.We find that the China Railway Express(CRE)significantly prevented the formation of such firms.Mechanism tests show:(i)the CRE has accelerated the speed of sales,which increased the overseas salesrevenue of firms;(ii)the economies of scale and the capital accumulation effectcaused by the CRE can help increase firms'solvency and development ability.Heterogeneity analysis indicates that the effect of the CRE on preventing theformation of zombie firms is mainly reflected in non-state-owned firms,firms inhighly competitive industries,and firms in the eastern region of China.We suggestthat China should continue to promote trade facilitation by expanding the CRE andstrengthening the market's dominant role in preventing the formation of zombie firms.Disadvantaged firms should seize the development opportunities brought by the CRE.
基金This work is supported in part by the National Key R&D Program of China under Grant 2021YFE0203700 and 2021YFA1003004in part by the Natural Science Foundation of Shanghai under Grand 23ZR1422200+1 种基金in part by the Shanghai Sailing Program under Grant 23YF1412800in part by the NSFC/RGC N CUHK 415/19,Grant ITF MHP/038/20,Grant CRF 8730063,Grant RGC 14300219,14302920,14301121,and CUHK Direct Grant for Research.
文摘Fast and accurate MRI reconstruction is a key concern in modern clinical practice.Recently,numerous Deep-Learning methods have been proposed for MRI reconstruction,however,they usually fail to reconstruct sharp details from the subsampled k-space data.To solve this problem,we propose a lightweight and accurate Edge Attention MRI Reconstruction Network(EAMRI)to reconstruct images with edge guidance.Specifically,we design an efficient Edge Prediction Network to directly predict accurate edges from the blurred image.Meanwhile,we propose a novel Edge Attention Module(EAM)to guide the image reconstruction utilizing the extracted edge priors,as inspired by the popular self-attention mechanism.EAM first projects the input image and edges into Q_(image),K_(edge),and V_(image),respectively.Then EAM pairs the Q_(image)with K_(edge)along the channel dimension,such that 1)it can search globally for the high-frequency image features that are activated by the edge priors;2)the overall computation burdens are largely reduced compared with the traditional spatial-wise attention.With the help of EAM,the predicted edge priors can effectively guide the model to reconstruct high-quality MR images with accurate edges.Extensive experiments show that our proposed EAMRI outperforms other methods with fewer parameters and can recover more accurate edges.
基金the National Social Science Foundation of China(Nos.15AJY017 and 16BJY183).
文摘This study uses the difference-in differences method to test the impact of a high-speed rail(HSR)service on the issuance of municipal corporate bonds(MCB)based on panel data for prefecture-level cities in China from 2003 to 2016.The study has three findings.First,HSR increased the scale of the issuance of MCB significantly.After conducting a series of robustness tests,the above conclusion remained robust.Second,HSR affected the issuance of MCB by increasing the city's financing demands and improving the city's financing capacity.Third,the effect of HSR on the issuance of MCB varied from city to city.Specifically,the promotion of the opening of HSR to the issuance of MCB was concentrated in remote and fast growing cities.High-speed rail can also effectively reduce the cost and shrink credit spreads of the MCB.This paper shows that it is necessary to further optimize the layout of HSR,release and exploit the financial resource reallocation effect of HSR,and provide financial support to the high-quality development of cities.
