We study the Nadaraya-Watson estimators for the drift function of two-sided reflected stochastic differential equations.The estimates,based on either the continuously observed process or the discretely observed proces...We study the Nadaraya-Watson estimators for the drift function of two-sided reflected stochastic differential equations.The estimates,based on either the continuously observed process or the discretely observed process,are considered.Under certain conditions,we prove the strong consistency and the asymptotic normality of the two estimators.Our method is also suitable for one-sided reflected stochastic differential equations.Simulation results demonstrate that the performance of our estimator is superior to that of the estimator proposed by Cholaquidis et al.(Stat Sin,2021,31:29-51).Several real data sets of the currency exchange rate are used to illustrate our proposed methodology.展开更多
This article deals with the reflecting function of the differential systems. The results are applied to discuss the stability of these differential systems.
We consider the problem of viscosity solution of integro-partial differential equation( IPDE in short) with one obstacle via the solution of reflected backward stochastic dif ferential equations(RBSDE in short) with j...We consider the problem of viscosity solution of integro-partial differential equation( IPDE in short) with one obstacle via the solution of reflected backward stochastic dif ferential equations(RBSDE in short) with jumps. We show the existence and uniqueness of a continuous viscosity solution of equation with non local terms, if the generator is not monotonous and Levy's measure is infinite.展开更多
Differential reflectance spectroscopy(DRS)is a powerful tool to study processes during thin-film growth,especially that of transition metal dichalcogenides and organic thin films.To satisfy the requirements for in sit...Differential reflectance spectroscopy(DRS)is a powerful tool to study processes during thin-film growth,especially that of transition metal dichalcogenides and organic thin films.To satisfy the requirements for in situ and real-time monitoring of film growth,including spectral resolution and sensitivity at the level of monolayers and even sub-monolayers,the most challenging technical task in DRS is to reduce noise to an extremely low level so that the best possible signal-to-noise ratio can be achieved.In this paper,we present a simplified and cost-effective DRS apparatus,with which we show that the measurement noise is mainly composed of thermal drift noise and explore the temperature-dependence of the DRS signal.Based on the results obtained,we propose an easily realized and effective scheme aiming to reduce the noise.Experimental results demonstrate that this scheme is effective in stabilizing reliable signals for a long period of several hours.Significant noise reduction is achieved,with the typical average noise of the DRS system being decreased to 0.05%over several hours.The improved DRS system is applied to study the growth of an organic semiconductor layer for an organic field-effect transistor device.The results indicate that the apparatus proposed in this paper has potential applications in fabrication of devices on the nanoscale and even the sub-nanoscale.展开更多
To quantify the pore characteristics of various macerals in Chang 7 lacustrine shales,macerals were effectively identified according to their optical and morphological characteristics,and the nanoscale pore structure ...To quantify the pore characteristics of various macerals in Chang 7 lacustrine shales,macerals were effectively identified according to their optical and morphological characteristics,and the nanoscale pore structure of macerals was observed by scanning electron microscope.Meanwhile,the reflectances of different positions in the same pieces of vitrinite or solid bitumen with heterogeneous pores development were measured.The results showed that the average contents of sapropelinite,liptinite,vitrinite,inertinite and solid bitumen are 42.7%,8.7%,13.6%,13.8% and 21.2%,respectively,which suggests that the source of the organic matter of the Chang 7 shales is a mixed source input.The organic pores of Chang 7 shales are enriched,and the pore shapes are mostly round or elliptical.The pore size of organic pores has a wide distribution,mainly concentrate in the range of 100-400 nm,and the average plane porosity of organic pores is 10.13%.The size order of the organic pores in various macerals is:solid bitumen<bituminite<alginite<vitrinite<fusinite<liptinite.The abundance order of organic matter pores of each maceral is as follows:alginite>fusinite>bituminite>solid bitumen>vitrinite>liptinite.OM pores are mainly contributed by bituminite,solid bitumen and fusinite.The plane porosity of bituminite increases with maturity.In the process of thermal evolution,the plane porosity of fusinite is distributed in the two ranges of 20%-28% and 1%-7%.The former is mainly the primary pores of the fusinite itself,and the latter is the secondary pores formed in the thermal evolution.As for the organic pores of other macerals,no obvious thermal evolution law was found.Meanwhile,the surface imperfections of vitrinite or solid bitumen is enhanced by the enrichment of organic pores(an increase in pore size or pore number),which may result in the underestimation of their reflectances.展开更多
Submarine micro-geomorphology is a geo-morphological type occurring in shallow and surface areas of seabed.The combined relationships and distribution of the micro-geomorphology indirectly reflect coupling relationshi...Submarine micro-geomorphology is a geo-morphological type occurring in shallow and surface areas of seabed.The combined relationships and distribution of the micro-geomorphology indirectly reflect coupling relationships among the sediment deposition,dynamic environment,and geomorphologic evolution.Spatial differentiation and dynamic changes in micro-geomorphology were studied based on acoustic data interpretation from a wide range(3200 km^(2))of the Huanghe(Yellow)River delta(HRD).The combination of the sub-bottom profiler and the side-scan sonar methods allowed for the identification of submarine shallow micro-geomorphologic types,as well as their scale and spatial distributions.There were seven typical micro-geomorphologic features in the shallow and surface areas of the HRD,including buried ancient channels,stratigraphic disturbances,scour troughs,sand waves,pits,erosional remnants,and sand spots.The coupling and superposition of the sediment,sediment characteristics,seabed scouring and silting,and hydrodynamic conditions of the Huanghe River had combined effects on the patterns of micro-geomorphologic types,characteristics,and ranges.From the perspective of acoustic profile interpretations,the scale,range,and spatial locations of the microgeomorphology in the HRD revealed seasonal variation characteristics,and the spatial distributions displayed significant regional differentiation characteristics.In addition,strong stratigraphic disturbances and areas with densely distributed buried ancient channels reflected the activity and instability of the submarine shallow strata.Through the interpretation of the sub-bottom profile detection data,the diversion processes of the flow paths in the lower reaches of the Huanghe River were obtained for a certain historical period in the coastal waters of the HRD.This study further clarified the relationships between the micro-geomorphologic features and spatial combinations,which is important for research on micro-geomorphologic features and their dynamic mechanisms.展开更多
基金partially supported by the National Natural Science Foundation of China(11871244)the Fundamental Research Funds for the Central Universities,JLU。
文摘We study the Nadaraya-Watson estimators for the drift function of two-sided reflected stochastic differential equations.The estimates,based on either the continuously observed process or the discretely observed process,are considered.Under certain conditions,we prove the strong consistency and the asymptotic normality of the two estimators.Our method is also suitable for one-sided reflected stochastic differential equations.Simulation results demonstrate that the performance of our estimator is superior to that of the estimator proposed by Cholaquidis et al.(Stat Sin,2021,31:29-51).Several real data sets of the currency exchange rate are used to illustrate our proposed methodology.
基金supported by the Natural Science Foundation of Jiangsu Educational Committee(02KJB110009).
文摘This article deals with the reflecting function of the differential systems. The results are applied to discuss the stability of these differential systems.
文摘We consider the problem of viscosity solution of integro-partial differential equation( IPDE in short) with one obstacle via the solution of reflected backward stochastic dif ferential equations(RBSDE in short) with jumps. We show the existence and uniqueness of a continuous viscosity solution of equation with non local terms, if the generator is not monotonous and Levy's measure is infinite.
基金This work was supported by the National Key Research and Development Program of China(Grant No.2017YFF0107003).
文摘Differential reflectance spectroscopy(DRS)is a powerful tool to study processes during thin-film growth,especially that of transition metal dichalcogenides and organic thin films.To satisfy the requirements for in situ and real-time monitoring of film growth,including spectral resolution and sensitivity at the level of monolayers and even sub-monolayers,the most challenging technical task in DRS is to reduce noise to an extremely low level so that the best possible signal-to-noise ratio can be achieved.In this paper,we present a simplified and cost-effective DRS apparatus,with which we show that the measurement noise is mainly composed of thermal drift noise and explore the temperature-dependence of the DRS signal.Based on the results obtained,we propose an easily realized and effective scheme aiming to reduce the noise.Experimental results demonstrate that this scheme is effective in stabilizing reliable signals for a long period of several hours.Significant noise reduction is achieved,with the typical average noise of the DRS system being decreased to 0.05%over several hours.The improved DRS system is applied to study the growth of an organic semiconductor layer for an organic field-effect transistor device.The results indicate that the apparatus proposed in this paper has potential applications in fabrication of devices on the nanoscale and even the sub-nanoscale.
基金This project was funded by the National Natural Science Foundation of China(41972161)the 2021 American Association of Petroleum Geologists Foundation Grants-in-Aid Program and Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(2020CX050103).
文摘To quantify the pore characteristics of various macerals in Chang 7 lacustrine shales,macerals were effectively identified according to their optical and morphological characteristics,and the nanoscale pore structure of macerals was observed by scanning electron microscope.Meanwhile,the reflectances of different positions in the same pieces of vitrinite or solid bitumen with heterogeneous pores development were measured.The results showed that the average contents of sapropelinite,liptinite,vitrinite,inertinite and solid bitumen are 42.7%,8.7%,13.6%,13.8% and 21.2%,respectively,which suggests that the source of the organic matter of the Chang 7 shales is a mixed source input.The organic pores of Chang 7 shales are enriched,and the pore shapes are mostly round or elliptical.The pore size of organic pores has a wide distribution,mainly concentrate in the range of 100-400 nm,and the average plane porosity of organic pores is 10.13%.The size order of the organic pores in various macerals is:solid bitumen<bituminite<alginite<vitrinite<fusinite<liptinite.The abundance order of organic matter pores of each maceral is as follows:alginite>fusinite>bituminite>solid bitumen>vitrinite>liptinite.OM pores are mainly contributed by bituminite,solid bitumen and fusinite.The plane porosity of bituminite increases with maturity.In the process of thermal evolution,the plane porosity of fusinite is distributed in the two ranges of 20%-28% and 1%-7%.The former is mainly the primary pores of the fusinite itself,and the latter is the secondary pores formed in the thermal evolution.As for the organic pores of other macerals,no obvious thermal evolution law was found.Meanwhile,the surface imperfections of vitrinite or solid bitumen is enhanced by the enrichment of organic pores(an increase in pore size or pore number),which may result in the underestimation of their reflectances.
基金Supported by the General Program of Natural Science Foundation of Shandong Province(No.ZR2020MD063)the Youth Program of Natural Science Foundation of Shandong Province(No.ZR2013DQ025)the National Natural Science Foundation of China and Shandong Province Joint Funds(No.U1706214)。
文摘Submarine micro-geomorphology is a geo-morphological type occurring in shallow and surface areas of seabed.The combined relationships and distribution of the micro-geomorphology indirectly reflect coupling relationships among the sediment deposition,dynamic environment,and geomorphologic evolution.Spatial differentiation and dynamic changes in micro-geomorphology were studied based on acoustic data interpretation from a wide range(3200 km^(2))of the Huanghe(Yellow)River delta(HRD).The combination of the sub-bottom profiler and the side-scan sonar methods allowed for the identification of submarine shallow micro-geomorphologic types,as well as their scale and spatial distributions.There were seven typical micro-geomorphologic features in the shallow and surface areas of the HRD,including buried ancient channels,stratigraphic disturbances,scour troughs,sand waves,pits,erosional remnants,and sand spots.The coupling and superposition of the sediment,sediment characteristics,seabed scouring and silting,and hydrodynamic conditions of the Huanghe River had combined effects on the patterns of micro-geomorphologic types,characteristics,and ranges.From the perspective of acoustic profile interpretations,the scale,range,and spatial locations of the microgeomorphology in the HRD revealed seasonal variation characteristics,and the spatial distributions displayed significant regional differentiation characteristics.In addition,strong stratigraphic disturbances and areas with densely distributed buried ancient channels reflected the activity and instability of the submarine shallow strata.Through the interpretation of the sub-bottom profile detection data,the diversion processes of the flow paths in the lower reaches of the Huanghe River were obtained for a certain historical period in the coastal waters of the HRD.This study further clarified the relationships between the micro-geomorphologic features and spatial combinations,which is important for research on micro-geomorphologic features and their dynamic mechanisms.
