For most pulsed atomic clocks, the Dick effect is one of the main limits to reach its frequency stability limitation due to quantum projection noise. In this paper, we measure the phase noise of the local oscillator i...For most pulsed atomic clocks, the Dick effect is one of the main limits to reach its frequency stability limitation due to quantum projection noise. In this paper, we measure the phase noise of the local oscillator in the Ramsey-CPT atomic clock and calculate the Dick effect induced Allan deviation based on a three-level atomic model, which is quite different from typical atomic clocks. We further present a detailed analysis of optimizing the sensitivity function and minimizing the Dick effect by interleaving lock. By optimizing the duty circle of laser pulses, average time during detection and optical intensity of laser beam, the Dick effect induced Allan deviation can be reduced to the level of 10 14.展开更多
In the microwave 199Hg＋ trapped-ion clock, the frequency instability degradation caused by the Dick effect is un- avoidable because of the periodical interrogating field. In this paper, the general expression of the ...In the microwave 199Hg＋ trapped-ion clock, the frequency instability degradation caused by the Dick effect is un- avoidable because of the periodical interrogating field. In this paper, the general expression of the sensitivity function g（t） to the frequency fluctuation of the interrogating field with Nπ-pulse （N is odd） is derived. According to the measured phase noise of the 40.5-GHz microwave synthesizer, the Dick-effect limited Allan deviation of our 199Hg＋ trapped-ion clock is worked out. The results indicate that the limited Allan deviations are about 1.75 ×10-13/√τ and 3.03 ×10-13/√τ respectively in the linear ion trap and in the two-segment extended linear ion trap under our present experimental parameters.展开更多
Herman Melville(1819-1891) is one of the famous writers in the history of American and world literature. Moby Dick is one of the masterpieces of Melville, and it is also his most famous ocean works in his late life. M...Herman Melville(1819-1891) is one of the famous writers in the history of American and world literature. Moby Dick is one of the masterpieces of Melville, and it is also his most famous ocean works in his late life. Moby Dick describes a story on Captain Ahab took revenge on white whale. This paper will discuss Captain Ahab's paranoid personality, and reveal how Melville reflected in the works: coexistence between human and nature. A brief description will be provided for the writer's life and his works, and then I will discuss Captain Ahab's paranoid personality through his whaling capturing process. Then, I will discuss obtaining principles of Captain Ahab, Mate Starbuck, Crew Ishmael, and reveal the Captain's tragic causes and reflected thinking. Finally, I will make a conclusion only if people adopt right obtaining principles to natural resources, could we live with nature altogether.展开更多
"Moby Dick"is an in-depth spiritual exploration about beliefs,religion,fate and nature with multi-layered meanings.This novel is based on a whale-hunting adventure,which turns out to be actually a vengeance-..."Moby Dick"is an in-depth spiritual exploration about beliefs,religion,fate and nature with multi-layered meanings.This novel is based on a whale-hunting adventure,which turns out to be actually a vengeance-seeking voyage.The plot is very simple,yet the meaning behind it is far from simple.Applying symbolism,Melville depicts a hostile relationship between men and nature,which is spotlighted by the conflict between Captain Ahab and Moby Dick.This thesis deals with the relationship between men and nature as presented in the novel,the symbolic meaning that Melville intends to convey and his attitude towards the ideal relationship between men and nature.展开更多
Nathaniel Hawthorne and Herman Melville are among the most important American dark romanticists. One of the similarities of their novels The Scarlet Letter and Moby Dick is symbolism. Even though the two authors adopt...Nathaniel Hawthorne and Herman Melville are among the most important American dark romanticists. One of the similarities of their novels The Scarlet Letter and Moby Dick is symbolism. Even though the two authors adopted similar symbols, they endowed them with varied meanings to express their ideas on human nature. This paper focused on some similar symbols in The Scarlet Letter and Moby Dick and offered an analysis of the similarities and differences between them. First, it is an introduction on thebackground information of two novels. Then, it comes the contrast and comparison of two pairs of symbols:Chillingworth versusAhab and the scarlet letter A versus Queequeg’s coffin.展开更多
In the American and British literature,Moby Dick written by Herman Melville is the magnum opus.The most imortant idea of the thesis is the revenge between Captain Ahab and the White Wheal.The thesis discusses the targ...In the American and British literature,Moby Dick written by Herman Melville is the magnum opus.The most imortant idea of the thesis is the revenge between Captain Ahab and the White Wheal.The thesis discusses the target and significance of the revenge through the character analysis of Ahab.Ahab's revenge shows the readers the determination of human's fighting against the Almighty God and Herman Melville's idea of harmonious co-existence between humans and the nature.展开更多
Moby Dick is a retrospective novel about life at sea as well as a vast philosophical allegory of life in general.The novel begins with a famous statement"Call me Ishmael".The identity of Ishmael is analyzed,...Moby Dick is a retrospective novel about life at sea as well as a vast philosophical allegory of life in general.The novel begins with a famous statement"Call me Ishmael".The identity of Ishmael is analyzed,revealing that he functions not only as an indispensable narrator,but as an actor—a sailor on the Pequod,and psychologically a religious wonderer and a truth seeker.展开更多
Moby-Dick, a great masterpiece by Herman Melville, is acclaimed as an epic of the sea such as no man has equaled. This thesis focuses on Ahab and the aesthetic sublime in Moby Dick. Ahab proves himself to be a figure ...Moby-Dick, a great masterpiece by Herman Melville, is acclaimed as an epic of the sea such as no man has equaled. This thesis focuses on Ahab and the aesthetic sublime in Moby Dick. Ahab proves himself to be a figure of the aesthetic sublime in his chasing and fighting against the giant whale.展开更多
Captain Ahab is a controversy and complicated figure in Moby Dick. The studies of Ahab in the past has become increasingly involved various aspects. Ahab is a figure with many faces, among which the most significant a...Captain Ahab is a controversy and complicated figure in Moby Dick. The studies of Ahab in the past has become increasingly involved various aspects. Ahab is a figure with many faces, among which the most significant and decisive ones are his individualist, arrogance and humanity. He persists in taking revenging on the white whale is quite compatible with such character. Besides, his fate is also leads to his attachment behavior. In this essay,I will mainly analyze the fate and characters of Ahab in order to help readers understand Moby Dick better.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0302101)the Initiative Program of State Key Laboratory of Precision Measurement Technology and Instruments
文摘For most pulsed atomic clocks, the Dick effect is one of the main limits to reach its frequency stability limitation due to quantum projection noise. In this paper, we measure the phase noise of the local oscillator in the Ramsey-CPT atomic clock and calculate the Dick effect induced Allan deviation based on a three-level atomic model, which is quite different from typical atomic clocks. We further present a detailed analysis of optimizing the sensitivity function and minimizing the Dick effect by interleaving lock. By optimizing the duty circle of laser pulses, average time during detection and optical intensity of laser beam, the Dick effect induced Allan deviation can be reduced to the level of 10 14.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11074248 and 11474320)
文摘In the microwave 199Hg＋ trapped-ion clock, the frequency instability degradation caused by the Dick effect is un- avoidable because of the periodical interrogating field. In this paper, the general expression of the sensitivity function g（t） to the frequency fluctuation of the interrogating field with Nπ-pulse （N is odd） is derived. According to the measured phase noise of the 40.5-GHz microwave synthesizer, the Dick-effect limited Allan deviation of our 199Hg＋ trapped-ion clock is worked out. The results indicate that the limited Allan deviations are about 1.75 ×10-13/√τ and 3.03 ×10-13/√τ respectively in the linear ion trap and in the two-segment extended linear ion trap under our present experimental parameters.
文摘Herman Melville(1819-1891) is one of the famous writers in the history of American and world literature. Moby Dick is one of the masterpieces of Melville, and it is also his most famous ocean works in his late life. Moby Dick describes a story on Captain Ahab took revenge on white whale. This paper will discuss Captain Ahab's paranoid personality, and reveal how Melville reflected in the works: coexistence between human and nature. A brief description will be provided for the writer's life and his works, and then I will discuss Captain Ahab's paranoid personality through his whaling capturing process. Then, I will discuss obtaining principles of Captain Ahab, Mate Starbuck, Crew Ishmael, and reveal the Captain's tragic causes and reflected thinking. Finally, I will make a conclusion only if people adopt right obtaining principles to natural resources, could we live with nature altogether.
文摘"Moby Dick"is an in-depth spiritual exploration about beliefs,religion,fate and nature with multi-layered meanings.This novel is based on a whale-hunting adventure,which turns out to be actually a vengeance-seeking voyage.The plot is very simple,yet the meaning behind it is far from simple.Applying symbolism,Melville depicts a hostile relationship between men and nature,which is spotlighted by the conflict between Captain Ahab and Moby Dick.This thesis deals with the relationship between men and nature as presented in the novel,the symbolic meaning that Melville intends to convey and his attitude towards the ideal relationship between men and nature.
文摘Nathaniel Hawthorne and Herman Melville are among the most important American dark romanticists. One of the similarities of their novels The Scarlet Letter and Moby Dick is symbolism. Even though the two authors adopted similar symbols, they endowed them with varied meanings to express their ideas on human nature. This paper focused on some similar symbols in The Scarlet Letter and Moby Dick and offered an analysis of the similarities and differences between them. First, it is an introduction on thebackground information of two novels. Then, it comes the contrast and comparison of two pairs of symbols:Chillingworth versusAhab and the scarlet letter A versus Queequeg’s coffin.
文摘In the American and British literature,Moby Dick written by Herman Melville is the magnum opus.The most imortant idea of the thesis is the revenge between Captain Ahab and the White Wheal.The thesis discusses the target and significance of the revenge through the character analysis of Ahab.Ahab's revenge shows the readers the determination of human's fighting against the Almighty God and Herman Melville's idea of harmonious co-existence between humans and the nature.
文摘Moby Dick is a retrospective novel about life at sea as well as a vast philosophical allegory of life in general.The novel begins with a famous statement"Call me Ishmael".The identity of Ishmael is analyzed,revealing that he functions not only as an indispensable narrator,but as an actor—a sailor on the Pequod,and psychologically a religious wonderer and a truth seeker.
文摘Moby-Dick, a great masterpiece by Herman Melville, is acclaimed as an epic of the sea such as no man has equaled. This thesis focuses on Ahab and the aesthetic sublime in Moby Dick. Ahab proves himself to be a figure of the aesthetic sublime in his chasing and fighting against the giant whale.
文摘Captain Ahab is a controversy and complicated figure in Moby Dick. The studies of Ahab in the past has become increasingly involved various aspects. Ahab is a figure with many faces, among which the most significant and decisive ones are his individualist, arrogance and humanity. He persists in taking revenging on the white whale is quite compatible with such character. Besides, his fate is also leads to his attachment behavior. In this essay,I will mainly analyze the fate and characters of Ahab in order to help readers understand Moby Dick better.
