Background:Investigating the ecological factors and processes shaping nest survival is of great importance for assessing the breeding success of bird populations and understanding their spatio-temporal dynamics.Here,t...Background:Investigating the ecological factors and processes shaping nest survival is of great importance for assessing the breeding success of bird populations and understanding their spatio-temporal dynamics.Here,this question is addressed for the Laughing Dove(Spilopelia senegalensis),an expanding Afro-tropical bird in the Tunisian oasis habitat.Methods:This study took place in Kettana oasis,in south-eastern Tunisia.Natural Laughing Dove nests were searched for and monitored by means of regular visits,from the discovery date until the end of the breeding attempt(i.e.fledging or failure).Data were then used to investigate the relevance of laying date,nest age(days after clutch initiation),nest height and vegetation structure in the close nest tree environment as predictors of daily nest survival rate,using logistic-exposure models that accounted for heterogeneity in monitoring period among the studied nests.Models including different combinations of covariates were ranked according to their AICc scores,and the modelaveraging technique was used for the assessment of the effects of covariates on daily nest survival rate.Results:Vegetation structure in the close nest tree environment and nest age provided important predictors of daily nest survival rate,whereas neither nest height nor laying date showed significant effects.Daily nest survival rate was negatively associated with the presence of date palm trees in the close nest tree environment,but it was positively related to nest age.Daily nest survival rate was higher during the post-hatching stage than during the pre-hatching stage.Conclusions:Nests placed on fruit trees close to clumps of palm trees suffered higher predation risks compared to those placed on fruit trees situated far from palm trees.This is probably because palm tree clumps provided refuges for nest predators,notably the Black Rat(Rattus rattus)which has been reported to be the main nest predator in the oasis habitat.The predatory activity of this rodent seemed more directed against eggs than nestlings,which may explain the observed increase in daily survival rate with nest age.展开更多
American society went through some especially speedy and drastic changes, after the World War II. Its transformation into a significant superpower as well as the horrors of the recent conflict is reflected in specific...American society went through some especially speedy and drastic changes, after the World War II. Its transformation into a significant superpower as well as the horrors of the recent conflict is reflected in specific American novels and in the writing of certain elite novelists. They focus on human loss and a consequent search for identity and problematic belonging in a world of prejudice and hostility. This search for identity and aspiration to conformity with the new change is among of the main features of Salinger＇s the Catcher in the Rye, Ellison＇s Invisible Man and Vonnegut＇s Slaughterhouse Five. The paper focuses on certain similarities in theme and form which link these three novels and examines the extent of presentation of the style of narration set in motion by all three writers.展开更多
When the birds laugh with the voice of joy,The willows drift[飘荡]with the sound of laugh;When the air laugh with our merry wits,The meadows[草地]laugh with lively green.Where our table with nuts and blueberries is sp...When the birds laugh with the voice of joy,The willows drift[飘荡]with the sound of laugh;When the air laugh with our merry wits,The meadows[草地]laugh with lively green.Where our table with nuts and blueberries is spread,Come live,and be merry,and join with me.展开更多
Xie Tian is now directing Night OwI Column,another film dealing with the common people,this time young sanitation workers in the 1980s.Even though China's film indus-try is in a mild slump at the mo-ment,we wish h...Xie Tian is now directing Night OwI Column,another film dealing with the common people,this time young sanitation workers in the 1980s.Even though China's film indus-try is in a mild slump at the mo-ment,we wish him the greatest of success.展开更多
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
文摘Background:Investigating the ecological factors and processes shaping nest survival is of great importance for assessing the breeding success of bird populations and understanding their spatio-temporal dynamics.Here,this question is addressed for the Laughing Dove(Spilopelia senegalensis),an expanding Afro-tropical bird in the Tunisian oasis habitat.Methods:This study took place in Kettana oasis,in south-eastern Tunisia.Natural Laughing Dove nests were searched for and monitored by means of regular visits,from the discovery date until the end of the breeding attempt(i.e.fledging or failure).Data were then used to investigate the relevance of laying date,nest age(days after clutch initiation),nest height and vegetation structure in the close nest tree environment as predictors of daily nest survival rate,using logistic-exposure models that accounted for heterogeneity in monitoring period among the studied nests.Models including different combinations of covariates were ranked according to their AICc scores,and the modelaveraging technique was used for the assessment of the effects of covariates on daily nest survival rate.Results:Vegetation structure in the close nest tree environment and nest age provided important predictors of daily nest survival rate,whereas neither nest height nor laying date showed significant effects.Daily nest survival rate was negatively associated with the presence of date palm trees in the close nest tree environment,but it was positively related to nest age.Daily nest survival rate was higher during the post-hatching stage than during the pre-hatching stage.Conclusions:Nests placed on fruit trees close to clumps of palm trees suffered higher predation risks compared to those placed on fruit trees situated far from palm trees.This is probably because palm tree clumps provided refuges for nest predators,notably the Black Rat(Rattus rattus)which has been reported to be the main nest predator in the oasis habitat.The predatory activity of this rodent seemed more directed against eggs than nestlings,which may explain the observed increase in daily survival rate with nest age.
文摘American society went through some especially speedy and drastic changes, after the World War II. Its transformation into a significant superpower as well as the horrors of the recent conflict is reflected in specific American novels and in the writing of certain elite novelists. They focus on human loss and a consequent search for identity and problematic belonging in a world of prejudice and hostility. This search for identity and aspiration to conformity with the new change is among of the main features of Salinger＇s the Catcher in the Rye, Ellison＇s Invisible Man and Vonnegut＇s Slaughterhouse Five. The paper focuses on certain similarities in theme and form which link these three novels and examines the extent of presentation of the style of narration set in motion by all three writers.
文摘When the birds laugh with the voice of joy,The willows drift[飘荡]with the sound of laugh;When the air laugh with our merry wits,The meadows[草地]laugh with lively green.Where our table with nuts and blueberries is spread,Come live,and be merry,and join with me.
文摘Xie Tian is now directing Night OwI Column,another film dealing with the common people,this time young sanitation workers in the 1980s.Even though China's film indus-try is in a mild slump at the mo-ment,we wish him the greatest of success.
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.
