Objective:The present study investigated the cytoprotective effects of a Pogonatherum paniceum extract prepared with 80%ethanol(PPE)using synchrotron radiation-based Fourier transform infrared(SR-FTIR)microspectroscop...Objective:The present study investigated the cytoprotective effects of a Pogonatherum paniceum extract prepared with 80%ethanol(PPE)using synchrotron radiation-based Fourier transform infrared(SR-FTIR)microspectroscopy and determined its phytochemical profile.Methods:The volatile and polyphenolic compounds in PPE were characterized using gas chromatography–mass spectrometry and liquid chromatography–mass spectrometry,respectively.The antioxidant capacity of PPE was evaluated using chemical and cell-based assays.The SR-FTIR microspectroscopy was performed to evaluate the cytoprotective effect of PPE by identifying changes in macromolecule composition in tert-butyl hydroperoxide(t BuOOH)-induced oxidative damage in RAW264.7 cells.Results:A total of 48 volatile compounds and 28 polyphenol components were found in PPE.PPE exhibited a high potential for antioxidant activity by scavenging the intracellular reactive oxygen species in t Bu OOH-induced oxidative damage in RAW264.7 cells.PPE treatment also significantly protected RAW264.7 cells against t BuOOH-induced toxicity and restored cell viability.The SR-FTIR analysis revealed that t BuOOH increased the lipid and ester lipid content in RAW264.7 cells.The PPE exerted a cytoprotective effect by decreasing the levels of lipid and ester lipid compounds that had been elevated by t BuOOH in RAW264.7 cells.These findings indicate that PPE has cytoprotective potential due to its ability to inhibit endogenous reactive oxygen species.Conclusion:This study extends the current knowledge on the phytochemistry of PPE and its antioxidant and cytoprotective effects.These findings support the use of SR-FTIR microspectroscopy to determine the cytoprotective effects of natural products.PPE extract may be a candidate compound for new therapeutics and nutraceuticals that target the prevention of oxidative stress-associated diseases.展开更多
The aim of this paper is to price power option with its underlying asset price following exponential normal inverse gaussian(NIG)process.We first find the risk neutral equivalent martingale measure Q by Esscher transf...The aim of this paper is to price power option with its underlying asset price following exponential normal inverse gaussian(NIG)process.We first find the risk neutral equivalent martingale measure Q by Esscher transform.Then,using the Fourier transform and its inverse,we derive the analytical pricing formulas of power options which are expressed in the form of Fourier integral.In addition,the fast Fourier transform(FFT)algorithm is applied to calculate these pricing formulas.Finally,Shangzheng 50ETF options are chosen to test our results.Estimating the parameters in NIG process by maximum likelihood method,we show that the NIG prices are much closer to market prices than the Black-Scholes-Merton(BSM)ones.展开更多
The aim of this paper is to prove another variation on the Heisenberg uncertainty principle,we generalize the quantitative uncertainty relations in n different(time-frequency)domains and we will give an algorithm for ...The aim of this paper is to prove another variation on the Heisenberg uncertainty principle,we generalize the quantitative uncertainty relations in n different(time-frequency)domains and we will give an algorithm for the signal recovery related to the canonical Fourier-Bessel transform.展开更多
The internal microstructures of rock materials, including mineral heterogeneity and intrinsic microdefects, exert a significant influence on their nonlinear mechanical and cracking behaviors. It is of great significan...The internal microstructures of rock materials, including mineral heterogeneity and intrinsic microdefects, exert a significant influence on their nonlinear mechanical and cracking behaviors. It is of great significance to accurately characterize the actual microstructures and their influence on stress and damage evolution inside the rocks. In this study, an image-based fast Fourier transform (FFT) method is developed for reconstructing the actual rock microstructures by combining it with the digital image processing (DIP) technique. A series of experimental investigations were conducted to acquire information regarding the actual microstructure and the mechanical properties. Based on these experimental evidences, the processed microstructure information, in conjunction with the proposed micromechanical model, is incorporated into the numerical calculation. The proposed image-based FFT method was firstly validated through uniaxial compression tests. Subsequently, it was employed to predict and analyze the influence of microstructure on macroscopic mechanical behaviors, local stress distribution and the internal crack evolution process in brittle rocks. The distribution of feldspar is considerably more heterogeneous and scattered than that of quartz, which results in a greater propensity for the formation of cracks in feldspar. It is observed that initial cracks and new cracks, including intragranular and boundary ones, ultimately coalesce and connect as the primary through cracks, which are predominantly distributed along the boundary of the feldspar. This phenomenon is also predicted by the proposed numerical method. The results indicate that the proposed numerical method provides an effective approach for analyzing, understanding and predicting the nonlinear mechanical and cracking behaviors of brittle rocks by taking into account the actual microstructure characteristics.展开更多
The capacity to diagnose faults in rolling bearings is of significant practical importance to ensure the normal operation of the equipment.Frequency-domain features can effectively enhance the identification of fault ...The capacity to diagnose faults in rolling bearings is of significant practical importance to ensure the normal operation of the equipment.Frequency-domain features can effectively enhance the identification of fault modes.However,existing methods often suffer from insufficient frequency-domain representation in practical applications,which greatly affects diagnostic performance.Therefore,this paper proposes a rolling bearing fault diagnosismethod based on aMulti-Scale FusionNetwork(MSFN)using the Time-Division Fourier Transform(TDFT).The method constructs multi-scale channels to extract time-domain and frequency-domain features of the signal in parallel.A multi-level,multi-scale filter-based approach is designed to extract frequency-domain features in a segmented manner.A cross-attention mechanism is introduced to facilitate the fusion of the extracted time-frequency domain features.The performance of the proposed method is validated using the CWRU and Ottawa datasets.The results show that the average accuracy of MSFN under complex noisy signals is 97.75%and 94.41%.The average accuracy under variable load conditions is 98.68%.This demonstrates its significant application potential compared to existing methods.展开更多
全波形反演作为一种高分辨率地下成像技术,在实际应用中仍面临低频数据缺失、周期跳跃以及噪声干扰等一系列挑战,因此提出一种基于Fourier近似Wasserstein距离的隐式全波形反演方法。在目标函数层面,利用Wasserstein距离与Fourier系数...全波形反演作为一种高分辨率地下成像技术,在实际应用中仍面临低频数据缺失、周期跳跃以及噪声干扰等一系列挑战,因此提出一种基于Fourier近似Wasserstein距离的隐式全波形反演方法。在目标函数层面,利用Wasserstein距离与Fourier系数之间的有界关系,构建基于Fourier近似的低频增强型目标函数。通过对地震数据中低波数成分进行加权增强,提高模型背景速度的恢复质量,从而有效缓解周期跳跃问题。在模型重参数化层面,引入基于正弦激活函数的神经网络对速度模型进行隐式表征,利用其连续的高维映射特性替代传统的离散网格表示,在提高模型表征自由度的同时为反演过程引入由参数化带来的平滑约束。选取Marmousi、Marmousi2和SEG Salt 3个典型模型,分别在低频缺失、线性初始模型、含噪场景和强散射介质等条件下评估方法的有效性。结果表明,在初始模型较差、低频缺失、噪声干扰和强散射等复杂条件下,所提方法均表现出优异的鲁棒性与收敛性,能够有效克服周期跳跃并显著提升反演精度。展开更多
基金supported by the Basic Research Fund from Thailand Science Research and Innovation through Sisaket Rajabhat University(grant number:FF.13/2564)。
文摘Objective:The present study investigated the cytoprotective effects of a Pogonatherum paniceum extract prepared with 80%ethanol(PPE)using synchrotron radiation-based Fourier transform infrared(SR-FTIR)microspectroscopy and determined its phytochemical profile.Methods:The volatile and polyphenolic compounds in PPE were characterized using gas chromatography–mass spectrometry and liquid chromatography–mass spectrometry,respectively.The antioxidant capacity of PPE was evaluated using chemical and cell-based assays.The SR-FTIR microspectroscopy was performed to evaluate the cytoprotective effect of PPE by identifying changes in macromolecule composition in tert-butyl hydroperoxide(t BuOOH)-induced oxidative damage in RAW264.7 cells.Results:A total of 48 volatile compounds and 28 polyphenol components were found in PPE.PPE exhibited a high potential for antioxidant activity by scavenging the intracellular reactive oxygen species in t Bu OOH-induced oxidative damage in RAW264.7 cells.PPE treatment also significantly protected RAW264.7 cells against t BuOOH-induced toxicity and restored cell viability.The SR-FTIR analysis revealed that t BuOOH increased the lipid and ester lipid content in RAW264.7 cells.The PPE exerted a cytoprotective effect by decreasing the levels of lipid and ester lipid compounds that had been elevated by t BuOOH in RAW264.7 cells.These findings indicate that PPE has cytoprotective potential due to its ability to inhibit endogenous reactive oxygen species.Conclusion:This study extends the current knowledge on the phytochemistry of PPE and its antioxidant and cytoprotective effects.These findings support the use of SR-FTIR microspectroscopy to determine the cytoprotective effects of natural products.PPE extract may be a candidate compound for new therapeutics and nutraceuticals that target the prevention of oxidative stress-associated diseases.
基金Supported by National Natural Science Foundation of China(11571089,11501164)Natural Science Founda-tion of Hebei Province(A2019205299)+1 种基金the Foundation of Hebei Education Department(ZD2018065,ZD2019053)Hebei Normal University(L2019Z01).
文摘The aim of this paper is to price power option with its underlying asset price following exponential normal inverse gaussian(NIG)process.We first find the risk neutral equivalent martingale measure Q by Esscher transform.Then,using the Fourier transform and its inverse,we derive the analytical pricing formulas of power options which are expressed in the form of Fourier integral.In addition,the fast Fourier transform(FFT)algorithm is applied to calculate these pricing formulas.Finally,Shangzheng 50ETF options are chosen to test our results.Estimating the parameters in NIG process by maximum likelihood method,we show that the NIG prices are much closer to market prices than the Black-Scholes-Merton(BSM)ones.
文摘The aim of this paper is to prove another variation on the Heisenberg uncertainty principle,we generalize the quantitative uncertainty relations in n different(time-frequency)domains and we will give an algorithm for the signal recovery related to the canonical Fourier-Bessel transform.
基金supported by the National Natural Science Foundation of China(Grant No.11802332)the China Scholarship Council(Grant No.202206435003)the Fundamental Research Funds for the Central Universities(Grant No.2024ZKPYLJ03).
文摘The internal microstructures of rock materials, including mineral heterogeneity and intrinsic microdefects, exert a significant influence on their nonlinear mechanical and cracking behaviors. It is of great significance to accurately characterize the actual microstructures and their influence on stress and damage evolution inside the rocks. In this study, an image-based fast Fourier transform (FFT) method is developed for reconstructing the actual rock microstructures by combining it with the digital image processing (DIP) technique. A series of experimental investigations were conducted to acquire information regarding the actual microstructure and the mechanical properties. Based on these experimental evidences, the processed microstructure information, in conjunction with the proposed micromechanical model, is incorporated into the numerical calculation. The proposed image-based FFT method was firstly validated through uniaxial compression tests. Subsequently, it was employed to predict and analyze the influence of microstructure on macroscopic mechanical behaviors, local stress distribution and the internal crack evolution process in brittle rocks. The distribution of feldspar is considerably more heterogeneous and scattered than that of quartz, which results in a greater propensity for the formation of cracks in feldspar. It is observed that initial cracks and new cracks, including intragranular and boundary ones, ultimately coalesce and connect as the primary through cracks, which are predominantly distributed along the boundary of the feldspar. This phenomenon is also predicted by the proposed numerical method. The results indicate that the proposed numerical method provides an effective approach for analyzing, understanding and predicting the nonlinear mechanical and cracking behaviors of brittle rocks by taking into account the actual microstructure characteristics.
基金fully supported by the Frontier Exploration Projects of Longmen Laboratory(No.LMQYTSKT034)Key Research and Development and Promotion of Special(Science and Technology)Project of Henan Province,China(No.252102210158)。
文摘The capacity to diagnose faults in rolling bearings is of significant practical importance to ensure the normal operation of the equipment.Frequency-domain features can effectively enhance the identification of fault modes.However,existing methods often suffer from insufficient frequency-domain representation in practical applications,which greatly affects diagnostic performance.Therefore,this paper proposes a rolling bearing fault diagnosismethod based on aMulti-Scale FusionNetwork(MSFN)using the Time-Division Fourier Transform(TDFT).The method constructs multi-scale channels to extract time-domain and frequency-domain features of the signal in parallel.A multi-level,multi-scale filter-based approach is designed to extract frequency-domain features in a segmented manner.A cross-attention mechanism is introduced to facilitate the fusion of the extracted time-frequency domain features.The performance of the proposed method is validated using the CWRU and Ottawa datasets.The results show that the average accuracy of MSFN under complex noisy signals is 97.75%and 94.41%.The average accuracy under variable load conditions is 98.68%.This demonstrates its significant application potential compared to existing methods.
文摘全波形反演作为一种高分辨率地下成像技术,在实际应用中仍面临低频数据缺失、周期跳跃以及噪声干扰等一系列挑战,因此提出一种基于Fourier近似Wasserstein距离的隐式全波形反演方法。在目标函数层面,利用Wasserstein距离与Fourier系数之间的有界关系,构建基于Fourier近似的低频增强型目标函数。通过对地震数据中低波数成分进行加权增强,提高模型背景速度的恢复质量,从而有效缓解周期跳跃问题。在模型重参数化层面,引入基于正弦激活函数的神经网络对速度模型进行隐式表征,利用其连续的高维映射特性替代传统的离散网格表示,在提高模型表征自由度的同时为反演过程引入由参数化带来的平滑约束。选取Marmousi、Marmousi2和SEG Salt 3个典型模型,分别在低频缺失、线性初始模型、含噪场景和强散射介质等条件下评估方法的有效性。结果表明,在初始模型较差、低频缺失、噪声干扰和强散射等复杂条件下,所提方法均表现出优异的鲁棒性与收敛性,能够有效克服周期跳跃并显著提升反演精度。
