Better soil structure promotes extension of plant roots thereby improving plant growth and yield.Differences in soil structure can be determined by changes in the three phases of soil,which in turn affect soil functio...Better soil structure promotes extension of plant roots thereby improving plant growth and yield.Differences in soil structure can be determined by changes in the three phases of soil,which in turn affect soil function and fertility levels.To compare the quality of soil structure under different conditions,we used Generalized Soil Structure Index(GSSI)as an indicator to determine the relationship between the“input”of soil three phases and the“output”of soil structure.To achieve optimum monitoring of comprehensive indicators,we used Successive Projections Algorithm(SPA)for differential processing based on 0.0–2.0 fractional orders and 3.0–10.0 integer orders and select important wavelengths to process soil spectral data.In addition,we also applied multivariate regression learning models including Gaussian Process Regression(GPR)and Artificial Neural Network(ANN),exploring potential capabilities of hyperspectral in predicting GSSI.The results showed that spectral reflection,mainly contributed by long-wave near-infrared radiation had an inverse relationship with GSSI values.The wavelengths between 404-418 nm and 2193–2400 nm were important GSSI wavelengths in fractional differential spectroscopy data,while those ranging from 543 to 999 nm were important GSSI wavelengths in integer differential spectroscopy data.Also,non-linear models were more accurate than linear models.In addition,wide neural networks were best suited for establishing fractional-order differentiation and second-order differentiation models,while fine Gaussian support vector machines were best suited for establishing first-order differentiation models.In terms of preprocessing,a differential order of 0.9 was found as the best choice.From the results,we propose that when constructing optimal prediction models,it is necessary to consider indicators,differential orders,and model adaptability.Above all,this study provided a new method for an in-depth analyses of generalized soil structure.This also fills the gap limiting the detection of soil three phases structural characteristics and their dynamic changes and provides a technical references for quantitative and rapid evaluation of soil structure,function,and quality.展开更多
The author considers the embedding problem of weighted Sobolev spaces H<sup>n</sup><sub>p</sub> in weighted L<sub>s</sub> spaces L<sub>s,r</sub>,and some sufficient cond...The author considers the embedding problem of weighted Sobolev spaces H<sup>n</sup><sub>p</sub> in weighted L<sub>s</sub> spaces L<sub>s,r</sub>,and some sufficient conditions and necessary conditions are given, when weight functions satisfy certain conditions.The author uses the results obtained to the qualitative analysis of the spectrum of 2n-order weighted differential operator,and gives some sufficient conditions and necessary conditions to ensure that the spectrum is discrete.展开更多
A new surface acoustic Wave differential quadraphase shift key（SAW DQPSK） spread spectrum （SS） signal matched filter based on the fusion of SS and differential modulation is reported. The design of multi-phase cod...A new surface acoustic Wave differential quadraphase shift key（SAW DQPSK） spread spectrum （SS） signal matched filter based on the fusion of SS and differential modulation is reported. The design of multi-phase coded SAW matched filter is proposed rather than another design of SAW DQPSK filter, which can cut in a half of the delay time of SAW DQPSK matched filter and SAW fixed delay line（FDL） used for differential demodulation. This breakthrough is made the system largely reduce a size and process much easily. This method can also be feasible in other SAW MPSK matched filter design especially when the modulation phase number is larger than 4. The design example and its experimental results are given.展开更多
In this paper, a family of non-monomial permutations over the finite field F2n with differential uniformity at most 6 is proposed, where n is a positive integer. The algebraic degree of these functions is also determi...In this paper, a family of non-monomial permutations over the finite field F2n with differential uniformity at most 6 is proposed, where n is a positive integer. The algebraic degree of these functions is also determined.展开更多
In the paper, the author addresses the Lyapunov characteristic spectrum of an ergodic autonomous ordinary differential system on a complete riemannian manifold of finite dimension such as the d-dimensional euclidean s...In the paper, the author addresses the Lyapunov characteristic spectrum of an ergodic autonomous ordinary differential system on a complete riemannian manifold of finite dimension such as the d-dimensional euclidean space ? d , not necessarily compact, by Liaowise spectral theorems that give integral expressions of Lyapunov exponents. In the context of smooth linear skew-product flows with Polish driving systems, the results are still valid. This paper seems to be an interesting contribution to the stability theory of ordinary differential systems with non-compact phase spaces.展开更多
An in-line fiber Fabry-Perot interferometer （FPI） based on the hollow-core photonic crystal fiber （HCPCF） for refractive index （RI） measurement is proposed in this paper. The FPI is formed by splicing both ends ...An in-line fiber Fabry-Perot interferometer （FPI） based on the hollow-core photonic crystal fiber （HCPCF） for refractive index （RI） measurement is proposed in this paper. The FPI is formed by splicing both ends of a short section of the HCPCF to single mode fibers （SMFs） and cleaving the SMF pigtail to a proper length. The RI response of the sensor is analyzed theoretically and demonstrated experimentally. The results show that the FPI sensor has linear response to external RI and good repeatability. The sensitivity calculated from the maximum fringe contrast is -136 dB/RIU. A new spectrum differential integration （SDI） method for signal processing is also presented in this study. In this method, the RI is obtained from the integrated intensity of the absolute difference between the interference spectrum and its smoothed spectrum. The results show that the sensitivity obtained from the integrated intensity is about -1.34× 10^5 dB/RIU. Compared with the maximum fringe contrast method, the new SDI method can provide the higher sensitivity, better linearity, improved reliability, and accuracy, and it＇s also convenient for automatic and fast signal processing in real-time monitoring of RI.展开更多
Broadly,the oxygen evolution reaction(OER)has been deeply understood as a significant part of energy conversion and storage.Nevertheless,the anions in the OER catalysts have been neglected for various reasons such as ...Broadly,the oxygen evolution reaction(OER)has been deeply understood as a significant part of energy conversion and storage.Nevertheless,the anions in the OER catalysts have been neglected for various reasons such as inactive sites,dissolution,and oxidation,amongst others.Herein,we applied a model catalyst s-Ni(OH)2 to track the anionic behavior in the catalyst during the electrochemical process to fill this gap.The advanced operando synchrotron radiation Fourier transform infrared(SR-FTIR)spectroscopy,synchrotron radiation photoelectron spectroscopy(SRPES)depth detection and differential X-ray absorption fine structure(D-XAFS)spectrum jointly point out that some oxidized sulfur species(SO_(4)^(2-))will selfoptimize new Ni–S bonds during OER process.Such amazing anionic self-optimization(ASO)behavior has never been observed in the OER process.Subsequently,the optimization-derived component shows a significantly improved electrocatalytic performance(activity,stability,etc.)compared to reference catalyst Ni(OH)_(2).Theoretical calculation further suggests that the ASO process indeed derives a thermodynamically stable structure of the OER catalyst,and then gives its superb catalytic performance by optimizing the thermodynamic and kinetic processes in the OER,respectively.This work demonstrates the vital role of anions in the electrochemical process,which will open up new perspectives for understanding OER and provide some new ideas in related fields(especially catalysis and chemistry).展开更多
基金funded by the National Natural Science Foundation of China(31871571,31371572)the earmarked fund for Shanxi Province Graduate Education Innovation Project(2022Y312)+3 种基金supported by Modern Agro-industry Technology Research System(2023CYJSTX02-23)Scientific and Technological Innovation Fund of Shanxi Agricultural University(2018YJ17,2020BQ32)Key Technologies R&D Program of Shanxi Province(201903D211002,201603D3111005)National Key R&D Program of China(2019YFC1710800)。
文摘Better soil structure promotes extension of plant roots thereby improving plant growth and yield.Differences in soil structure can be determined by changes in the three phases of soil,which in turn affect soil function and fertility levels.To compare the quality of soil structure under different conditions,we used Generalized Soil Structure Index(GSSI)as an indicator to determine the relationship between the“input”of soil three phases and the“output”of soil structure.To achieve optimum monitoring of comprehensive indicators,we used Successive Projections Algorithm(SPA)for differential processing based on 0.0–2.0 fractional orders and 3.0–10.0 integer orders and select important wavelengths to process soil spectral data.In addition,we also applied multivariate regression learning models including Gaussian Process Regression(GPR)and Artificial Neural Network(ANN),exploring potential capabilities of hyperspectral in predicting GSSI.The results showed that spectral reflection,mainly contributed by long-wave near-infrared radiation had an inverse relationship with GSSI values.The wavelengths between 404-418 nm and 2193–2400 nm were important GSSI wavelengths in fractional differential spectroscopy data,while those ranging from 543 to 999 nm were important GSSI wavelengths in integer differential spectroscopy data.Also,non-linear models were more accurate than linear models.In addition,wide neural networks were best suited for establishing fractional-order differentiation and second-order differentiation models,while fine Gaussian support vector machines were best suited for establishing first-order differentiation models.In terms of preprocessing,a differential order of 0.9 was found as the best choice.From the results,we propose that when constructing optimal prediction models,it is necessary to consider indicators,differential orders,and model adaptability.Above all,this study provided a new method for an in-depth analyses of generalized soil structure.This also fills the gap limiting the detection of soil three phases structural characteristics and their dynamic changes and provides a technical references for quantitative and rapid evaluation of soil structure,function,and quality.
基金Supported by the National Natural Science Fundation of Chinathe Natural Science Foundation of Inner Mongolia.
文摘The author considers the embedding problem of weighted Sobolev spaces H<sup>n</sup><sub>p</sub> in weighted L<sub>s</sub> spaces L<sub>s,r</sub>,and some sufficient conditions and necessary conditions are given, when weight functions satisfy certain conditions.The author uses the results obtained to the qualitative analysis of the spectrum of 2n-order weighted differential operator,and gives some sufficient conditions and necessary conditions to ensure that the spectrum is discrete.
基金National High Technology Research and Development Programof China(2002AA325040)
文摘A new surface acoustic Wave differential quadraphase shift key（SAW DQPSK） spread spectrum （SS） signal matched filter based on the fusion of SS and differential modulation is reported. The design of multi-phase coded SAW matched filter is proposed rather than another design of SAW DQPSK filter, which can cut in a half of the delay time of SAW DQPSK matched filter and SAW fixed delay line（FDL） used for differential demodulation. This breakthrough is made the system largely reduce a size and process much easily. This method can also be feasible in other SAW MPSK matched filter design especially when the modulation phase number is larger than 4. The design example and its experimental results are given.
基金supported by the National Science Foundation of China under Grant Nos.11401172 and 61672212
文摘In this paper, a family of non-monomial permutations over the finite field F2n with differential uniformity at most 6 is proposed, where n is a positive integer. The algebraic degree of these functions is also determined.
基金supported by the National Natural Science Foundation of China (Grant No. 10671088)the Major State Basic Research Development Program of China (Grant No. 2006CB805903)
文摘In the paper, the author addresses the Lyapunov characteristic spectrum of an ergodic autonomous ordinary differential system on a complete riemannian manifold of finite dimension such as the d-dimensional euclidean space ? d , not necessarily compact, by Liaowise spectral theorems that give integral expressions of Lyapunov exponents. In the context of smooth linear skew-product flows with Polish driving systems, the results are still valid. This paper seems to be an interesting contribution to the stability theory of ordinary differential systems with non-compact phase spaces.
基金This research is supported by the National Natural Science Foundations of China （Grant Nos. 61174018 and 61505097） and Fundamental research funds of Shandong University, China （Grant No.2014YQ009）.
文摘An in-line fiber Fabry-Perot interferometer （FPI） based on the hollow-core photonic crystal fiber （HCPCF） for refractive index （RI） measurement is proposed in this paper. The FPI is formed by splicing both ends of a short section of the HCPCF to single mode fibers （SMFs） and cleaving the SMF pigtail to a proper length. The RI response of the sensor is analyzed theoretically and demonstrated experimentally. The results show that the FPI sensor has linear response to external RI and good repeatability. The sensitivity calculated from the maximum fringe contrast is -136 dB/RIU. A new spectrum differential integration （SDI） method for signal processing is also presented in this study. In this method, the RI is obtained from the integrated intensity of the absolute difference between the interference spectrum and its smoothed spectrum. The results show that the sensitivity obtained from the integrated intensity is about -1.34× 10^5 dB/RIU. Compared with the maximum fringe contrast method, the new SDI method can provide the higher sensitivity, better linearity, improved reliability, and accuracy, and it＇s also convenient for automatic and fast signal processing in real-time monitoring of RI.
基金supported in part by the National Key R&D Program of China(2017YFA0303500)the National Natural Science Foundation of China(U1932201,21727801,and 51902303)+4 种基金the National Natural Science Foundation of China-Ministry of Foreign Affairs and International Cooperation of Italy(51861135202)CAS International Partnership Program(211134KYSB20190063)Key Research Program of Frontier Sciences(QYZDB-SSW-SLH018)the University of Science and Technology of China start-up fundCAS Interdisciplinary Innovation Team。
文摘Broadly,the oxygen evolution reaction(OER)has been deeply understood as a significant part of energy conversion and storage.Nevertheless,the anions in the OER catalysts have been neglected for various reasons such as inactive sites,dissolution,and oxidation,amongst others.Herein,we applied a model catalyst s-Ni(OH)2 to track the anionic behavior in the catalyst during the electrochemical process to fill this gap.The advanced operando synchrotron radiation Fourier transform infrared(SR-FTIR)spectroscopy,synchrotron radiation photoelectron spectroscopy(SRPES)depth detection and differential X-ray absorption fine structure(D-XAFS)spectrum jointly point out that some oxidized sulfur species(SO_(4)^(2-))will selfoptimize new Ni–S bonds during OER process.Such amazing anionic self-optimization(ASO)behavior has never been observed in the OER process.Subsequently,the optimization-derived component shows a significantly improved electrocatalytic performance(activity,stability,etc.)compared to reference catalyst Ni(OH)_(2).Theoretical calculation further suggests that the ASO process indeed derives a thermodynamically stable structure of the OER catalyst,and then gives its superb catalytic performance by optimizing the thermodynamic and kinetic processes in the OER,respectively.This work demonstrates the vital role of anions in the electrochemical process,which will open up new perspectives for understanding OER and provide some new ideas in related fields(especially catalysis and chemistry).
