The integration of cloud computing into traditional industrial control systems is accelerating the evolution of Industrial Cyber-Physical System(ICPS),enhancing intelligence and autonomy.However,this transition also e...The integration of cloud computing into traditional industrial control systems is accelerating the evolution of Industrial Cyber-Physical System(ICPS),enhancing intelligence and autonomy.However,this transition also expands the attack surface,introducing critical security vulnerabilities.To address these challenges,this article proposes a hybrid intrusion detection scheme for securing ICPSs that combines system state anomaly and network traffic anomaly detection.Specifically,an improved variation-Bayesian-based noise covariance-adaptive nonlinear Kalman filtering(IVB-NCA-NLKF)method is developed to model nonlinear system dynamics,enabling optimal state estimation in multi-sensor ICPS environments.Intrusions within the physical sensing system are identified by analyzing residual discrepancies between predicted and observed system states.Simultaneously,an adaptive network traffic anomaly detection mechanism is introduced,leveraging learned traffic patterns to detect node-and network-level anomalies through pattern matching.Extensive experiments on a simulated network control system demonstrate that the proposed framework achieves higher detection accuracy(92.14%)with a reduced false alarm rate(0.81%).Moreover,it not only detects known attacks and vulnerabilities but also uncovers stealthy attacks that induce system state deviations,providing a robust and comprehensive security solution for the safety protection of ICPS.展开更多
Under the National Innovation-Driven Development Strategy,establishing a scientifically sound evaluation system for normal university students’innovation and entrepreneurship capabilities serves as a crucial foundati...Under the National Innovation-Driven Development Strategy,establishing a scientifically sound evaluation system for normal university students’innovation and entrepreneurship capabilities serves as a crucial foundation for optimizing innovation education models and enhancing teacher candidates’comprehensive competencies.Based on existing indicator frameworks,we designed a questionnaire and applied exploratory factor analysis(EFA)to screen indicators,reduce dimensionality,and analyze weighting.This process identified key metrics for evaluating pedagogical students’innovation capacities,ultimately constructing a targeted assessment system for normal university students.The study provides theoretical support for cultivating teacher trainees’innovative capabilities while contributing to the national innovation strategy implementation.展开更多
In this paper,cohyponormal weighted composition operators on the Fock space over C^(N)are characterized completely.We also consider a class of weighted composition operators on the Fock space over C^(N)which are both ...In this paper,cohyponormal weighted composition operators on the Fock space over C^(N)are characterized completely.We also consider a class of weighted composition operators on the Fock space over C^(N)which are both posinormal and coposinormal.As an application,we obtain the characterization of hyponormal,cohyponormal,posinormal and coposinormal composition operators on the Fock space over C^(N).展开更多
The cultivation of the educator spirit among normal university students provides dual guidance in theory and practice for higher education institutions to train future teachers with noble educational sentiments and pr...The cultivation of the educator spirit among normal university students provides dual guidance in theory and practice for higher education institutions to train future teachers with noble educational sentiments and professional qualities.This study elaborates on the essential connotation of the educator spirit from six perspectives:guiding philosophy,spiritual cultivation,internal requirements,essential requirements,the soul of teacher ethics,and sources of motivation.On this basis,it explains the three major dilemmas in cultivating the educator spirit among normal university students:the cognitive dilemma regarding the understanding of the value of the educator spirit and educational identity,the integration dilemma caused by the disconnection between educational curriculum design and the penetration of the educator spirit,and the alienation dilemma arising from improper connection between educational practice and the educator spirit.Therefore,it is proposed to incorporate the educator spirit into the evaluation system for normal university students,by deepening the understanding of values,optimizing curriculum design,strengthening practice orientation,and comprehensively motivating and evaluating normal university students’recognition and practice of the educator spirit,in order to promote the inheritance and innovation of the educator spirit.展开更多
The General Secretary pointed out that“artificial intelligence is an important driving force for the new round of scientific and technological revolution and industrial transformation,and will have a profound impact ...The General Secretary pointed out that“artificial intelligence is an important driving force for the new round of scientific and technological revolution and industrial transformation,and will have a profound impact on the global economic and social development and the progress of human civilization”[1].With the in-depth advancement of China’s education reform,the training model for pre-service teachers has also ushered in changes.Based on the innovative“4+1”on-site(teaching)practicum for pre-service teachers at a university in Jiangsu Province,this study explores the application of artificial intelligence technology in the“4+1”on-site(teaching)practicum process for pre-service teachers.By using artificial intelligence technology to assist teaching design,conduct classroom behavior analysis,and generate teaching reflections,this study aims to enhance the personalization and effectiveness of pre-service teachers’internships.This research is intended to provide certain references for empowering normal education practice with artificial intelligence technology,and has positive significance for promoting the digital transformation of teacher education.展开更多
Detecting abnormal cervical cells is crucial for early identification and timely treatment of cervical cancer.However,this task is challenging due to the morphological similarities between abnormal and normal cells an...Detecting abnormal cervical cells is crucial for early identification and timely treatment of cervical cancer.However,this task is challenging due to the morphological similarities between abnormal and normal cells and the significant variations in cell size.Pathologists often refer to surrounding cells to identify abnormalities.To emulate this slide examination behavior,this study proposes a Multi-Scale Feature Fusion Network(MSFF-Net)for detecting cervical abnormal cells.MSFF-Net employs a Cross-Scale Pooling Model(CSPM)to effectively capture diverse features and contextual information,ranging from local details to the overall structure.Additionally,a Multi-Scale Fusion Attention(MSFA)module is introduced to mitigate the impact of cell size variations by adaptively fusing local and global information at different scales.To handle the complex environment of cervical cell images,such as cell adhesion and overlapping,the Inner-CIoU loss function is utilized to more precisely measure the overlap between bounding boxes,thereby improving detection accuracy in such scenarios.Experimental results on the Comparison detector dataset demonstrate that MSFF-Net achieves a mean average precision(mAP)of 63.2%,outperforming state-of-the-art methods while maintaining a relatively small number of parameters(26.8 M).This study highlights the effectiveness of multi-scale feature fusion in enhancing the detection of cervical abnormal cells,contributing to more accurate and efficient cervical cancer screening.展开更多
In this paper,we obtain a normality criterion for families of meromorphic functions concerning‘wandering’shared functions,which generalizes and improves Montel’s criterion and the related results due to Schwick,Xu-...In this paper,we obtain a normality criterion for families of meromorphic functions concerning‘wandering’shared functions,which generalizes and improves Montel’s criterion and the related results due to Schwick,Xu-Fang,Xu-Qiu,and Grahl-Nevo.Also,a normality relationship between two families is given.展开更多
We consider the hyponormality of the block dual Toeplitz operator S_(Φ)acting on the orthogonal complement of the vector valued weighted Bergman space (A_(α)^(2)(D,C^(n)))^(⊥).We provide a necessary and sufficient ...We consider the hyponormality of the block dual Toeplitz operator S_(Φ)acting on the orthogonal complement of the vector valued weighted Bergman space (A_(α)^(2)(D,C^(n)))^(⊥).We provide a necessary and sufficient condition for the hyponormality of SΦwith matrix valued bounded harmonic symbol.In this process,we introduce a function g_(w,s)∈(A_(α)^(2)(D))^(⊥),which is similar to the reproducing kernel of the weighted Bergman space A_(α)^(2)(D).We also give some additional applications of the function gw,s∈(A_(α)^(2)(D))^(⊥).展开更多
In this paper, the influence of s-semipermutable, c~#-normal, subnormally embedded and ss-quasinormal subgroups on the p-nilpotency of finite groups is investigated and some recent results are generalized.
Synchronized dual-wavelength mode-locked laser is investigated numerically and experimentally in the normal dispersion regime.A programmable optical processor is introduced to shape the spectral profile and adjust the...Synchronized dual-wavelength mode-locked laser is investigated numerically and experimentally in the normal dispersion regime.A programmable optical processor is introduced to shape the spectral profile and adjust the net dispersion,which is demonstrated be a convenient and reliable approach to generate dual-color solitons.The time-stretch dispersive Fourier transform and frequency-resolved optical grating techniques are utilized to measure the spectral and temporal characteristics of dual-color solitons,respectively.The numerical results are consistent with experimental results.This work may facilitate the development of filter-based mode-locked laser and the understanding of multi-wavelength soliton dynamics.展开更多
Rock avalanches frequently lead to catastrophic consequences due to their unpredictably high mobility.Numerous researchers have studied the shear behavior of granular materials under various conditions,attributing the...Rock avalanches frequently lead to catastrophic consequences due to their unpredictably high mobility.Numerous researchers have studied the shear behavior of granular materials under various conditions,attributing the high mobility to ultralow resistance.However,the underlying physical mechanism of frictional weakening remains unclear.This study utilizes the discrete element method(DEM)incorporating the fragment replacement model to simulate plane shear flows under various normal stresses(0.2 e1.2 MPa)and shear velocities(0.01e2 m/s).The findings reveal a localized shear band characterized by a J-shaped velocity profile and high granular temperature,and a concentrated distribution of weak contact forces forms at a shear velocity exceeding 0.1 m/s and normal stress above 0.6 MPa.Moreover,frictional weakening is observed with increasing normal stress from 0.2 MPa to 1.2 MPa and increasing shear velocity from 0.1 m/s to 2 m/s.The evolution of the steady-state friction coefficient can be divided into two stages:an initial stage(I)and a weakening stage(II).During stage I,the steady-state friction coefficient slightly increases until reaching a peak value.However,upon entering stage II,it gradually decreases and approaches an ultimate value.The velocity-and normal stress-dependent frictional weakening can be attributed to shear localization and embedded packing structure induced by particle breakage,respectively.Finally,an optimized m(I)model is proposed to capture the full evolution of the friction coefficient with the shear strain rate,which can improve our understanding of rock avalanche dynamics.展开更多
In this paper, let T be a bounded linear operator on a complex Hilbert H. We give and prove that every p-w-hyponormal operator has Bishop's property(β) and spectral properties; Quasi-similar p-w-hyponormal operat...In this paper, let T be a bounded linear operator on a complex Hilbert H. We give and prove that every p-w-hyponormal operator has Bishop's property(β) and spectral properties; Quasi-similar p-w-hyponormal operators have equal spectra and equal essential spectra. Finally, for p-w-hyponormal operators, we give a kind of proof of its normality by use of properties of partial isometry.展开更多
3-(4-Chlorophenyl)-7-[2-(piperazin-1-yl)ethoxy]-4H-chromen-4-one(CPEO-43)is a derivative of soybean isoflavone(SI),synthesized by introducing a chlorine atom and a piperazine group into the structure of natural SI.In ...3-(4-Chlorophenyl)-7-[2-(piperazin-1-yl)ethoxy]-4H-chromen-4-one(CPEO-43)is a derivative of soybean isoflavone(SI),synthesized by introducing a chlorine atom and a piperazine group into the structure of natural SI.In vitro experiments have demonstrated that CPEO-43 exhibits a notable inhibitory effect on both A549 cells and HCT116 cells.For the further development and utilization of CPEO-43,this study aims to establish and validate a liquid chromatography-tandem mass spectrometry(LC-MS/MS)quantitative analysis method for the pharmacokinetic study of CPEO-43.Normal rats were intragastrically administered different doses(2,6,and 20 mg/kg)of CPEO-43,and blood was taken from the ocular venous plexus at different time points.The blood concentration of CPEO-43 at different time points was determined using LC-MS/MS technology,and the pharmacokinetic parameters of the compound were calculated using the pharmacokinetic software DAS.The results indicated that the established LC-MS/MS method complies with the standards for bioanalytical method validation in the Chinese Pharmacopoeia(CHP)and can be applied to the pharmacokinetic study of CPEO-43.The pharmacokinetic software DAS non-compartmental model was successfully used to calculate the C_(max),T_(max),t_(1/2),AUC_(0-∞),MRTs,CL,and Vd pharmacokinetic parameters of the compound at different doses.The results were as follows:62.0±10.5,222.0±28.7,and 1384.5±376.4 ng/mL;8.5±1.2,6.0±0.0,and 11.0±6.2 h;15.6,15.0,and 18.5 h;1517.8±317.0,5328.7±864.4,and 45556.3±22735.6 ng·h/mL;17.8±1.2,17.7±0.8,and 20.0±3.2 h;1370.3±305.9,1153.5±205.6,and 505.3±179.8 mL/kg/h;30843.0±7458.0,24344.0±5237.0,and 13950.3±5996.9 mL/kg.These characteristics are of great significance for understanding the in vivo process of the drug,formulating dosing regimens,and evaluating the safety and efficacy of the drug.展开更多
In this article, we give an operator transform T （＊） from class A operator to the class of hyponormal operators. It is different from the operator transform T defined by M. Ch and T. Yamazaki. Then, we show that σ...In this article, we give an operator transform T （＊） from class A operator to the class of hyponormal operators. It is different from the operator transform T defined by M. Ch and T. Yamazaki. Then, we show that σ（T ） = σ（ T （＊）） and σa（T ）／{0} = σa（ T （＊））／{0}, in case T belongs to class A. Next, we obtain some relations between T and T （9）.展开更多
The approximate point spectrum properties of p-ω-hyponormal operators are given and proved. In faet, it is a generalization of approximate point speetrum properties of ω- hyponormal operators. The relation of spectr...The approximate point spectrum properties of p-ω-hyponormal operators are given and proved. In faet, it is a generalization of approximate point speetrum properties of ω- hyponormal operators. The relation of spectra and numerical range of p-ω-hyponormal operators is obtained, On the other hand, for p-ω-hyponormal operators T,it is showed that if Y is normal,then T is also normal.展开更多
This paper uses the methods of questionnaire and interview to investigate the basic status quo and components of teachers identity of undergraduates majoring in normal university. The results show that: (1) The genera...This paper uses the methods of questionnaire and interview to investigate the basic status quo and components of teachers identity of undergraduates majoring in normal university. The results show that: (1) The general level of teachers professional identity of normal school students is above average, but there are differences in dimensional development. (2) Normal students of different genders have no differences in teachers professional identity and various dimensions. There are significant differences in the total score of teachers professional identity, pre-service preparation and professional will among the normal students of different grades. (3) Normal students teacher identity may be influenced by factors such as motivation, personal factors and family background.展开更多
In steel squeeze casting process, the working condition of a punch was very rigorous. The abnormal failure models of an H13 punch, such as plastic rubbed damnification, could not be avoided easily. Based on the analys...In steel squeeze casting process, the working condition of a punch was very rigorous. The abnormal failure models of an H13 punch, such as plastic rubbed damnification, could not be avoided easily. Based on the analysis of the flow stress and the friction-shearing stress of an H13 punch in steel squeeze casting process, the following results were obtained： if the flow stress of an H13 punch was smaller than its friction-shearing stress, these abnormal failures could not be avoided; and if there were some protection measures that enable the flow stress to have a greater value than its friction-shearing one, the abnormal failures would not occur. In the production of 45^# steel valves and catenary system components, the flow stress of a lateral H13 punch without any protection measure was about 29 MPa and its friction-shearing stress was about 51 MPa, then, the abnormal failures occurred; however, when the protection measures of the punch enabled its working temperature to have a value below 682 ℃ its flow stress was greater than its friction-shearing stress, and the abnormal failures were avoided.展开更多
By using the definition of Hausdorff distance, we prove some normality criteria for families of meromorphic algebroid functions. Some examples are given to complement the theory in this article.
基金supported by the National Natural Science Foundation of China(NSFC)under grant No.62371187the Hunan Provincial Natural Science Foundation of China under Grant Nos.2024JJ8309 and 2023JJ50495.
文摘The integration of cloud computing into traditional industrial control systems is accelerating the evolution of Industrial Cyber-Physical System(ICPS),enhancing intelligence and autonomy.However,this transition also expands the attack surface,introducing critical security vulnerabilities.To address these challenges,this article proposes a hybrid intrusion detection scheme for securing ICPSs that combines system state anomaly and network traffic anomaly detection.Specifically,an improved variation-Bayesian-based noise covariance-adaptive nonlinear Kalman filtering(IVB-NCA-NLKF)method is developed to model nonlinear system dynamics,enabling optimal state estimation in multi-sensor ICPS environments.Intrusions within the physical sensing system are identified by analyzing residual discrepancies between predicted and observed system states.Simultaneously,an adaptive network traffic anomaly detection mechanism is introduced,leveraging learned traffic patterns to detect node-and network-level anomalies through pattern matching.Extensive experiments on a simulated network control system demonstrate that the proposed framework achieves higher detection accuracy(92.14%)with a reduced false alarm rate(0.81%).Moreover,it not only detects known attacks and vulnerabilities but also uncovers stealthy attacks that induce system state deviations,providing a robust and comprehensive security solution for the safety protection of ICPS.
基金Mid-term Results of the 2024 Langfang Normal University Special Teaching Reform Project on Innovation and Entrepreneurship Education Reform,“Research on the Evaluation System of Innovation and Entrepreneurship Ability for Normal University Students Based on Big Data Application-A Case Study of Langfang Normal University”(Project No.:CXJG2024-06)。
文摘Under the National Innovation-Driven Development Strategy,establishing a scientifically sound evaluation system for normal university students’innovation and entrepreneurship capabilities serves as a crucial foundation for optimizing innovation education models and enhancing teacher candidates’comprehensive competencies.Based on existing indicator frameworks,we designed a questionnaire and applied exploratory factor analysis(EFA)to screen indicators,reduce dimensionality,and analyze weighting.This process identified key metrics for evaluating pedagogical students’innovation capacities,ultimately constructing a targeted assessment system for normal university students.The study provides theoretical support for cultivating teacher trainees’innovative capabilities while contributing to the national innovation strategy implementation.
基金Supported by the National Natural Science Foundation of China(Grant No.12271134)Shanxi Scholarship Council of China(Grant No.2020-089)Program of Graduate Bilingual Curriculum Construction in Shanxi Normal University(Grant No.YJSSY201903).
文摘In this paper,cohyponormal weighted composition operators on the Fock space over C^(N)are characterized completely.We also consider a class of weighted composition operators on the Fock space over C^(N)which are both posinormal and coposinormal.As an application,we obtain the characterization of hyponormal,cohyponormal,posinormal and coposinormal composition operators on the Fock space over C^(N).
基金Study on 2024 Teacher Education Curriculum Reform in Henan Province(2024-JSJYYB-010)。
文摘The cultivation of the educator spirit among normal university students provides dual guidance in theory and practice for higher education institutions to train future teachers with noble educational sentiments and professional qualities.This study elaborates on the essential connotation of the educator spirit from six perspectives:guiding philosophy,spiritual cultivation,internal requirements,essential requirements,the soul of teacher ethics,and sources of motivation.On this basis,it explains the three major dilemmas in cultivating the educator spirit among normal university students:the cognitive dilemma regarding the understanding of the value of the educator spirit and educational identity,the integration dilemma caused by the disconnection between educational curriculum design and the penetration of the educator spirit,and the alienation dilemma arising from improper connection between educational practice and the educator spirit.Therefore,it is proposed to incorporate the educator spirit into the evaluation system for normal university students,by deepening the understanding of values,optimizing curriculum design,strengthening practice orientation,and comprehensively motivating and evaluating normal university students’recognition and practice of the educator spirit,in order to promote the inheritance and innovation of the educator spirit.
基金General Project of Philosophy and Social Sciences in Jiangsu Universities“Exploration and Research on the‘4+1’Educational Practice of Normal Students under Digital Transformation”(2024SJYB1714)Key Project of Educational and Teaching Reform Research in Nanjing Normal University Taizhou College“Research on the Diversified‘4+1’Educational Practice of Normal Students Based on the SFIC Model under Digital Transformation”(2023JG12001)。
文摘The General Secretary pointed out that“artificial intelligence is an important driving force for the new round of scientific and technological revolution and industrial transformation,and will have a profound impact on the global economic and social development and the progress of human civilization”[1].With the in-depth advancement of China’s education reform,the training model for pre-service teachers has also ushered in changes.Based on the innovative“4+1”on-site(teaching)practicum for pre-service teachers at a university in Jiangsu Province,this study explores the application of artificial intelligence technology in the“4+1”on-site(teaching)practicum process for pre-service teachers.By using artificial intelligence technology to assist teaching design,conduct classroom behavior analysis,and generate teaching reflections,this study aims to enhance the personalization and effectiveness of pre-service teachers’internships.This research is intended to provide certain references for empowering normal education practice with artificial intelligence technology,and has positive significance for promoting the digital transformation of teacher education.
基金funded by the China Chongqing Municipal Science and Technology Bureau,grant numbers 2024TIAD-CYKJCXX0121,2024NSCQ-LZX0135Chongqing Municipal Commission of Housing and Urban-Rural Development,grant number CKZ2024-87+3 种基金the Chongqing University of Technology graduate education high-quality development project,grant number gzlsz202401the Chongqing University of Technology-Chongqing LINGLUE Technology Co.,Ltd.,Electronic Information(Artificial Intelligence)graduate joint training basethe Postgraduate Education and Teaching Reform Research Project in Chongqing,grant number yjg213116the Chongqing University of Technology-CISDI Chongqing Information Technology Co.,Ltd.,Computer Technology graduate joint training base.
文摘Detecting abnormal cervical cells is crucial for early identification and timely treatment of cervical cancer.However,this task is challenging due to the morphological similarities between abnormal and normal cells and the significant variations in cell size.Pathologists often refer to surrounding cells to identify abnormalities.To emulate this slide examination behavior,this study proposes a Multi-Scale Feature Fusion Network(MSFF-Net)for detecting cervical abnormal cells.MSFF-Net employs a Cross-Scale Pooling Model(CSPM)to effectively capture diverse features and contextual information,ranging from local details to the overall structure.Additionally,a Multi-Scale Fusion Attention(MSFA)module is introduced to mitigate the impact of cell size variations by adaptively fusing local and global information at different scales.To handle the complex environment of cervical cell images,such as cell adhesion and overlapping,the Inner-CIoU loss function is utilized to more precisely measure the overlap between bounding boxes,thereby improving detection accuracy in such scenarios.Experimental results on the Comparison detector dataset demonstrate that MSFF-Net achieves a mean average precision(mAP)of 63.2%,outperforming state-of-the-art methods while maintaining a relatively small number of parameters(26.8 M).This study highlights the effectiveness of multi-scale feature fusion in enhancing the detection of cervical abnormal cells,contributing to more accurate and efficient cervical cancer screening.
基金Supported by the National Natural Science Foundation of China(Grant No.11471163)。
文摘In this paper,we obtain a normality criterion for families of meromorphic functions concerning‘wandering’shared functions,which generalizes and improves Montel’s criterion and the related results due to Schwick,Xu-Fang,Xu-Qiu,and Grahl-Nevo.Also,a normality relationship between two families is given.
基金Supported by the Scientific Research Fund of Liaoning Provincial Education Department of China (Grant No.LJKMZ20221405)the National Natural Science Foundation of China (Grant No.12031002)。
文摘We consider the hyponormality of the block dual Toeplitz operator S_(Φ)acting on the orthogonal complement of the vector valued weighted Bergman space (A_(α)^(2)(D,C^(n)))^(⊥).We provide a necessary and sufficient condition for the hyponormality of SΦwith matrix valued bounded harmonic symbol.In this process,we introduce a function g_(w,s)∈(A_(α)^(2)(D))^(⊥),which is similar to the reproducing kernel of the weighted Bergman space A_(α)^(2)(D).We also give some additional applications of the function gw,s∈(A_(α)^(2)(D))^(⊥).
基金Supported by SRFPYED(2017ZDX041)and SRFPYED(2016ZDX151)
文摘In this paper, the influence of s-semipermutable, c~#-normal, subnormally embedded and ss-quasinormal subgroups on the p-nilpotency of finite groups is investigated and some recent results are generalized.
基金Project supported by the Innovation Program for Quantum Science and Technology(Grant No.2023ZD0301000)the National Natural Science Foundation of China(Grant Nos.12434018,62475073,1243000542,11621404,11561121003,11727812,61775059,12074122,62405090,62035005,and 11704123)+1 种基金the Natural Science Foundation of Shanghai(Grant No.23ZR1419000)China Postdoctoral Science Foundation(Grant Nos.2023M741188 and 2024T170275)。
文摘Synchronized dual-wavelength mode-locked laser is investigated numerically and experimentally in the normal dispersion regime.A programmable optical processor is introduced to shape the spectral profile and adjust the net dispersion,which is demonstrated be a convenient and reliable approach to generate dual-color solitons.The time-stretch dispersive Fourier transform and frequency-resolved optical grating techniques are utilized to measure the spectral and temporal characteristics of dual-color solitons,respectively.The numerical results are consistent with experimental results.This work may facilitate the development of filter-based mode-locked laser and the understanding of multi-wavelength soliton dynamics.
基金supported by the National Key Research and Development Program of China(Grant Nos.2023YFC3008300 and 2023YFC3008302)the National Natural Science Foundation of China(Grant No.U22A20603).
文摘Rock avalanches frequently lead to catastrophic consequences due to their unpredictably high mobility.Numerous researchers have studied the shear behavior of granular materials under various conditions,attributing the high mobility to ultralow resistance.However,the underlying physical mechanism of frictional weakening remains unclear.This study utilizes the discrete element method(DEM)incorporating the fragment replacement model to simulate plane shear flows under various normal stresses(0.2 e1.2 MPa)and shear velocities(0.01e2 m/s).The findings reveal a localized shear band characterized by a J-shaped velocity profile and high granular temperature,and a concentrated distribution of weak contact forces forms at a shear velocity exceeding 0.1 m/s and normal stress above 0.6 MPa.Moreover,frictional weakening is observed with increasing normal stress from 0.2 MPa to 1.2 MPa and increasing shear velocity from 0.1 m/s to 2 m/s.The evolution of the steady-state friction coefficient can be divided into two stages:an initial stage(I)and a weakening stage(II).During stage I,the steady-state friction coefficient slightly increases until reaching a peak value.However,upon entering stage II,it gradually decreases and approaches an ultimate value.The velocity-and normal stress-dependent frictional weakening can be attributed to shear localization and embedded packing structure induced by particle breakage,respectively.Finally,an optimized m(I)model is proposed to capture the full evolution of the friction coefficient with the shear strain rate,which can improve our understanding of rock avalanche dynamics.
基金Natural Science and Education Foundation of Henan Province(2007110016)
文摘In this paper, let T be a bounded linear operator on a complex Hilbert H. We give and prove that every p-w-hyponormal operator has Bishop's property(β) and spectral properties; Quasi-similar p-w-hyponormal operators have equal spectra and equal essential spectra. Finally, for p-w-hyponormal operators, we give a kind of proof of its normality by use of properties of partial isometry.
基金Scientific Research Projects of Hebei North University(Grant No.XJ2024022).
文摘3-(4-Chlorophenyl)-7-[2-(piperazin-1-yl)ethoxy]-4H-chromen-4-one(CPEO-43)is a derivative of soybean isoflavone(SI),synthesized by introducing a chlorine atom and a piperazine group into the structure of natural SI.In vitro experiments have demonstrated that CPEO-43 exhibits a notable inhibitory effect on both A549 cells and HCT116 cells.For the further development and utilization of CPEO-43,this study aims to establish and validate a liquid chromatography-tandem mass spectrometry(LC-MS/MS)quantitative analysis method for the pharmacokinetic study of CPEO-43.Normal rats were intragastrically administered different doses(2,6,and 20 mg/kg)of CPEO-43,and blood was taken from the ocular venous plexus at different time points.The blood concentration of CPEO-43 at different time points was determined using LC-MS/MS technology,and the pharmacokinetic parameters of the compound were calculated using the pharmacokinetic software DAS.The results indicated that the established LC-MS/MS method complies with the standards for bioanalytical method validation in the Chinese Pharmacopoeia(CHP)and can be applied to the pharmacokinetic study of CPEO-43.The pharmacokinetic software DAS non-compartmental model was successfully used to calculate the C_(max),T_(max),t_(1/2),AUC_(0-∞),MRTs,CL,and Vd pharmacokinetic parameters of the compound at different doses.The results were as follows:62.0±10.5,222.0±28.7,and 1384.5±376.4 ng/mL;8.5±1.2,6.0±0.0,and 11.0±6.2 h;15.6,15.0,and 18.5 h;1517.8±317.0,5328.7±864.4,and 45556.3±22735.6 ng·h/mL;17.8±1.2,17.7±0.8,and 20.0±3.2 h;1370.3±305.9,1153.5±205.6,and 505.3±179.8 mL/kg/h;30843.0±7458.0,24344.0±5237.0,and 13950.3±5996.9 mL/kg.These characteristics are of great significance for understanding the in vivo process of the drug,formulating dosing regimens,and evaluating the safety and efficacy of the drug.
基金supported by Science Foundation of Ministry of Education of China (208081)Technology and pioneering project in Henan Provice (102300410012)Education Foundation of Henan Province (2007110016, 2008B110006)
文摘In this article, we give an operator transform T （＊） from class A operator to the class of hyponormal operators. It is different from the operator transform T defined by M. Ch and T. Yamazaki. Then, we show that σ（T ） = σ（ T （＊）） and σa（T ）／{0} = σa（ T （＊））／{0}, in case T belongs to class A. Next, we obtain some relations between T and T （9）.
文摘The approximate point spectrum properties of p-ω-hyponormal operators are given and proved. In faet, it is a generalization of approximate point speetrum properties of ω- hyponormal operators. The relation of spectra and numerical range of p-ω-hyponormal operators is obtained, On the other hand, for p-ω-hyponormal operators T,it is showed that if Y is normal,then T is also normal.
文摘This paper uses the methods of questionnaire and interview to investigate the basic status quo and components of teachers identity of undergraduates majoring in normal university. The results show that: (1) The general level of teachers professional identity of normal school students is above average, but there are differences in dimensional development. (2) Normal students of different genders have no differences in teachers professional identity and various dimensions. There are significant differences in the total score of teachers professional identity, pre-service preparation and professional will among the normal students of different grades. (3) Normal students teacher identity may be influenced by factors such as motivation, personal factors and family background.
文摘In steel squeeze casting process, the working condition of a punch was very rigorous. The abnormal failure models of an H13 punch, such as plastic rubbed damnification, could not be avoided easily. Based on the analysis of the flow stress and the friction-shearing stress of an H13 punch in steel squeeze casting process, the following results were obtained： if the flow stress of an H13 punch was smaller than its friction-shearing stress, these abnormal failures could not be avoided; and if there were some protection measures that enable the flow stress to have a greater value than its friction-shearing one, the abnormal failures would not occur. In the production of 45^# steel valves and catenary system components, the flow stress of a lateral H13 punch without any protection measure was about 29 MPa and its friction-shearing stress was about 51 MPa, then, the abnormal failures occurred; however, when the protection measures of the punch enabled its working temperature to have a value below 682 ℃ its flow stress was greater than its friction-shearing stress, and the abnormal failures were avoided.
基金Sponsored by the NSFC (10871076)the RFDP (20050574002)
文摘By using the definition of Hausdorff distance, we prove some normality criteria for families of meromorphic algebroid functions. Some examples are given to complement the theory in this article.
