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 Pouni area is made up of basalts belonging to the Boromo belt, lamprophyres and granitoids. These geological formations are similar to geological formations of the same type in other regions of the Palaeoproterozo...The Pouni area is made up of basalts belonging to the Boromo belt, lamprophyres and granitoids. These geological formations are similar to geological formations of the same type in other regions of the Palaeoproterozoic domain of the Man/Leo shield. This study, which focused on the petrographic and geochemical characteristics of these geological formations, led to the following main conclusions: The lamprophyres are basic plutonic rocks that cut through other geological formations. The basalt belongs to the northern part of the Borormo belt and is thought to be a relic of overthickened oceanic plateaus. There are two groups of granitoid rocks. The granodiorite has a geochemical signature close to that of Archean TTGs and is metaluminous in character. It has a low potassium content. The minor element and rare earth element spectra indicate that it could be derived from partial melting of basic magmatic rocks. Biotite granites are peraluminous and highly potassic. Minor element contents and rare earth spectra indicate that they could be derived from partial melting of felsic materials. Geotectonic diagrams show that the granitoids identified in the Pouni zone were emplaced in an active tectonic context, similar to that of present-day subduction zones.展开更多
South of Godé, in the central-western region of Burkina Faso, granitoids of Paleoproterozoic age are similar to those of the Man/Leo shield. This study focused on the petrographic and geochemical characteristics ...South of Godé, in the central-western region of Burkina Faso, granitoids of Paleoproterozoic age are similar to those of the Man/Leo shield. This study focused on the petrographic and geochemical characteristics of these granitoids, with the following results: 1) The tonalite that outcrops in the south-west of the study area belongs to the TTG group or first generation granitoids. They are most often ribboned at outcrop and have a geochemical signature close to that of Archean TTGs. Tonalite has a metaluminous character and the REE spectrum indicates that it may be derived from partial melting of basic magmatic rocks. 2) Biotite granites have no outcrop structure. They are weakly metaluminous to peraluminous and potassic to highly potassic. Their rare earth spectra indicate that they may be derived from the partial melting of TTG granitoids. 3) Geotectonic diagrams show that the granitoids studied to the south of Godé were emplaced in an active tectonic context similar to that of present-day subduction zones.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
In this paper,on the basis of analyzing farmers' dominant position in society and explanation of farmers' rationality,we make use of Maslow's hierarchy theory of needs to divide farmers' needs into thr...In this paper,on the basis of analyzing farmers' dominant position in society and explanation of farmers' rationality,we make use of Maslow's hierarchy theory of needs to divide farmers' needs into three levels in accordance with the different stages: survival needs,interpersonal harmony and social responsibility,which are the needs hierarchies for farmers to satisfy themselves. We combine Maslow's hierarchy theory of needs and farmers' rationality and confirm that farmers do have rationality and it is in a dynamic condition.展开更多
At 18:37 on June 16,the Shenzhou 9 manned spaceship, with its crew of three, was launched into orbit on top of an upgraded LM-2F rocket from the Jiuquan Satellite Launch Center, commencing the manned rendezvous and do...At 18:37 on June 16,the Shenzhou 9 manned spaceship, with its crew of three, was launched into orbit on top of an upgraded LM-2F rocket from the Jiuquan Satellite Launch Center, commencing the manned rendezvous and docking mission with Tiangong 1. They spent over a week living and working on the Tiangong 1 space展开更多
There is no-one in the field of weather broadcasting in Tibet who does notknow about Gyila: Top 10 Youth of China, China’s Outstanding Scientist, winner of the 5th China Youth Scientific Progress, and winner of first...There is no-one in the field of weather broadcasting in Tibet who does notknow about Gyila: Top 10 Youth of China, China’s Outstanding Scientist, winner of the 5th China Youth Scientific Progress, and winner of first May 4th Medal for Tibetan Youths.What people tell of him are legendary stories. Actually, he is an ordinary man who has cut a brilliant figure in work.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 Pouni area is made up of basalts belonging to the Boromo belt, lamprophyres and granitoids. These geological formations are similar to geological formations of the same type in other regions of the Palaeoproterozoic domain of the Man/Leo shield. This study, which focused on the petrographic and geochemical characteristics of these geological formations, led to the following main conclusions: The lamprophyres are basic plutonic rocks that cut through other geological formations. The basalt belongs to the northern part of the Borormo belt and is thought to be a relic of overthickened oceanic plateaus. There are two groups of granitoid rocks. The granodiorite has a geochemical signature close to that of Archean TTGs and is metaluminous in character. It has a low potassium content. The minor element and rare earth element spectra indicate that it could be derived from partial melting of basic magmatic rocks. Biotite granites are peraluminous and highly potassic. Minor element contents and rare earth spectra indicate that they could be derived from partial melting of felsic materials. Geotectonic diagrams show that the granitoids identified in the Pouni zone were emplaced in an active tectonic context, similar to that of present-day subduction zones.
文摘South of Godé, in the central-western region of Burkina Faso, granitoids of Paleoproterozoic age are similar to those of the Man/Leo shield. This study focused on the petrographic and geochemical characteristics of these granitoids, with the following results: 1) The tonalite that outcrops in the south-west of the study area belongs to the TTG group or first generation granitoids. They are most often ribboned at outcrop and have a geochemical signature close to that of Archean TTGs. Tonalite has a metaluminous character and the REE spectrum indicates that it may be derived from partial melting of basic magmatic rocks. 2) Biotite granites have no outcrop structure. They are weakly metaluminous to peraluminous and potassic to highly potassic. Their rare earth spectra indicate that they may be derived from the partial melting of TTG granitoids. 3) Geotectonic diagrams show that the granitoids studied to the south of Godé were emplaced in an active tectonic context similar to that of present-day subduction zones.
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.
文摘In this paper,on the basis of analyzing farmers' dominant position in society and explanation of farmers' rationality,we make use of Maslow's hierarchy theory of needs to divide farmers' needs into three levels in accordance with the different stages: survival needs,interpersonal harmony and social responsibility,which are the needs hierarchies for farmers to satisfy themselves. We combine Maslow's hierarchy theory of needs and farmers' rationality and confirm that farmers do have rationality and it is in a dynamic condition.
文摘At 18:37 on June 16,the Shenzhou 9 manned spaceship, with its crew of three, was launched into orbit on top of an upgraded LM-2F rocket from the Jiuquan Satellite Launch Center, commencing the manned rendezvous and docking mission with Tiangong 1. They spent over a week living and working on the Tiangong 1 space
文摘There is no-one in the field of weather broadcasting in Tibet who does notknow about Gyila: Top 10 Youth of China, China’s Outstanding Scientist, winner of the 5th China Youth Scientific Progress, and winner of first May 4th Medal for Tibetan Youths.What people tell of him are legendary stories. Actually, he is an ordinary man who has cut a brilliant figure in work.