It is important to calculate the reachable domain(RD)of the manned lunar mission to evaluate whether a lunar landing site could be reached by the spacecraft. In this paper, the RD of free return orbits is quickly eval...It is important to calculate the reachable domain(RD)of the manned lunar mission to evaluate whether a lunar landing site could be reached by the spacecraft. In this paper, the RD of free return orbits is quickly evaluated and calculated via the classification and regression neural networks. An efficient databasegeneration method is developed for obtaining eight types of free return orbits and then the RD is defined by the orbit’s inclination and right ascension of ascending node(RAAN) at the perilune. A classify neural network and a regression network are trained respectively. The former is built for classifying the type of the RD, and the latter is built for calculating the inclination and RAAN of the RD. The simulation results show that two neural networks are well trained. The classification model has an accuracy of more than 99% and the mean square error of the regression model is less than 0.01°on the test set. Moreover, a serial strategy is proposed to combine the two surrogate models and a recognition tool is built to evaluate whether a lunar site could be reached. The proposed deep learning method shows the superiority in computation efficiency compared with the traditional double two-body model.展开更多
The study of Wallace Stevens has a long and varied history. His life, poetry and philosophy have been interpreted in the demensions of romanticism, modernism, postmodernism and ecologism, with focuses on specific aspe...The study of Wallace Stevens has a long and varied history. His life, poetry and philosophy have been interpreted in the demensions of romanticism, modernism, postmodernism and ecologism, with focuses on specific aspects such as linguistic structure, the feminine, painting, music and faith. In recent years, studies of Stevens have expanded to include the Chinese elements and the relationship between imagination and reality in his poetry. This thesis intends to examine how irony, ambiguity, tension and paradox cooperate in “The Snow Man” to refresh the reader on man-nature relationship, to understand how Wallace Stevens reflects and reconciles the existential angst of “nothingness” popular in the early 20th century by this poem, and develops a positive or even optimistic attitude.展开更多
Flannery O’Connor is one of the representative figures of American Southern writers.Being recognized as the most outstanding writer of the American South after Faulkner,she has great influence in the literary world.H...Flannery O’Connor is one of the representative figures of American Southern writers.Being recognized as the most outstanding writer of the American South after Faulkner,she has great influence in the literary world.Her works are always shrouded in a strange and grotesque atmosphere and full of death as well as religious metaphors.The protagonists are a series of American Southern freaks struggling with the crisis of spiritual belief.The protagonists of her novel A Good Man is Hard to Find are a hypocritical believer in the world of sinners and a lost man suffering in the midst of real sin,thus O’Connor uses the highest form of violence-death to bring ultimate redemption to them.In people’s conception,violence and redemption are often opposite to each other,but O’Connor uses bloody and violent plots to explore the theme of religious salvation,integrating and unifying the two contrary concepts to form her unique and profound violent redemption writing.展开更多
The architecture and working principle of coordinated search and rescue system of unmanned/manned aircraft,which is composed of manned/unmanned aircraft and manned aircraft,were first introduced,and they can cooperate...The architecture and working principle of coordinated search and rescue system of unmanned/manned aircraft,which is composed of manned/unmanned aircraft and manned aircraft,were first introduced,and they can cooperate with each other to complete a search and rescue task.Secondly,a threat assessment method based on meteorological data was proposed,and potential meteorological threats,such as storms and rainfall,can be predicted by collecting and analyzing meteorological data.Finally,an experiment was carried out to evaluate the performance of the proposed method in different scenarios.The experimental results show that the coordinated search and rescue system of unmanned/manned aircraft can be used to effectively assess meteorological threats and provide accurate search and rescue guidance.展开更多
This study explores the significance,current research landscape,and conceptualization of sports safety promotion.Safety in sports is fundamental to youth physical activities,and an excessive focus on or neglect of saf...This study explores the significance,current research landscape,and conceptualization of sports safety promotion.Safety in sports is fundamental to youth physical activities,and an excessive focus on or neglect of safety is unwarranted.Globally,numerous countries have extensively researched sports safety promotion and implemented diverse strategies.Drawing from KABP(Knowledge,Attitude,Behavior,Practice)theory and 4M(Man,Machine,Medium,Management)management,this paper presents a conceptual framework for sports safety promotion.It integrates these theories to devise a comprehensive accident prevention model within a sports safety promotion system.The framework prioritizes enhancing students’safety literacy and underscores the practical application of safety knowledge and skills in simulated sports settings following structured safety education.It aims to enhance students’competency and proficiency in averting sports-related injuries.展开更多
基金supported by the National Natural Science Foundation of China (12072365)the Natural Science Foundation of Hunan Province of China (2020JJ4657)。
文摘It is important to calculate the reachable domain(RD)of the manned lunar mission to evaluate whether a lunar landing site could be reached by the spacecraft. In this paper, the RD of free return orbits is quickly evaluated and calculated via the classification and regression neural networks. An efficient databasegeneration method is developed for obtaining eight types of free return orbits and then the RD is defined by the orbit’s inclination and right ascension of ascending node(RAAN) at the perilune. A classify neural network and a regression network are trained respectively. The former is built for classifying the type of the RD, and the latter is built for calculating the inclination and RAAN of the RD. The simulation results show that two neural networks are well trained. The classification model has an accuracy of more than 99% and the mean square error of the regression model is less than 0.01°on the test set. Moreover, a serial strategy is proposed to combine the two surrogate models and a recognition tool is built to evaluate whether a lunar site could be reached. The proposed deep learning method shows the superiority in computation efficiency compared with the traditional double two-body model.
文摘The study of Wallace Stevens has a long and varied history. His life, poetry and philosophy have been interpreted in the demensions of romanticism, modernism, postmodernism and ecologism, with focuses on specific aspects such as linguistic structure, the feminine, painting, music and faith. In recent years, studies of Stevens have expanded to include the Chinese elements and the relationship between imagination and reality in his poetry. This thesis intends to examine how irony, ambiguity, tension and paradox cooperate in “The Snow Man” to refresh the reader on man-nature relationship, to understand how Wallace Stevens reflects and reconciles the existential angst of “nothingness” popular in the early 20th century by this poem, and develops a positive or even optimistic attitude.
文摘Flannery O’Connor is one of the representative figures of American Southern writers.Being recognized as the most outstanding writer of the American South after Faulkner,she has great influence in the literary world.Her works are always shrouded in a strange and grotesque atmosphere and full of death as well as religious metaphors.The protagonists are a series of American Southern freaks struggling with the crisis of spiritual belief.The protagonists of her novel A Good Man is Hard to Find are a hypocritical believer in the world of sinners and a lost man suffering in the midst of real sin,thus O’Connor uses the highest form of violence-death to bring ultimate redemption to them.In people’s conception,violence and redemption are often opposite to each other,but O’Connor uses bloody and violent plots to explore the theme of religious salvation,integrating and unifying the two contrary concepts to form her unique and profound violent redemption writing.
基金the Study on the Impact of the Construction and Development of Southwest Plateau Airport on the Ecological Environment(CZKY2023032).
文摘The architecture and working principle of coordinated search and rescue system of unmanned/manned aircraft,which is composed of manned/unmanned aircraft and manned aircraft,were first introduced,and they can cooperate with each other to complete a search and rescue task.Secondly,a threat assessment method based on meteorological data was proposed,and potential meteorological threats,such as storms and rainfall,can be predicted by collecting and analyzing meteorological data.Finally,an experiment was carried out to evaluate the performance of the proposed method in different scenarios.The experimental results show that the coordinated search and rescue system of unmanned/manned aircraft can be used to effectively assess meteorological threats and provide accurate search and rescue guidance.
文摘This study explores the significance,current research landscape,and conceptualization of sports safety promotion.Safety in sports is fundamental to youth physical activities,and an excessive focus on or neglect of safety is unwarranted.Globally,numerous countries have extensively researched sports safety promotion and implemented diverse strategies.Drawing from KABP(Knowledge,Attitude,Behavior,Practice)theory and 4M(Man,Machine,Medium,Management)management,this paper presents a conceptual framework for sports safety promotion.It integrates these theories to devise a comprehensive accident prevention model within a sports safety promotion system.The framework prioritizes enhancing students’safety literacy and underscores the practical application of safety knowledge and skills in simulated sports settings following structured safety education.It aims to enhance students’competency and proficiency in averting sports-related injuries.
