Various properties of a necklace vortex system formed around a rectangular plate standing vertically on a flat ground wall were investigated by visualizations produced by injecting fluorescent dye into a water channel...Various properties of a necklace vortex system formed around a rectangular plate standing vertically on a flat ground wall were investigated by visualizations produced by injecting fluorescent dye into a water channel flow. As a result, it was found that the necklace vortex pattern had three steady systems depending on the Reynolds number Reh, the relative height h/δ of the rectangular plate compared with the laminar boundary layer thickness and the aspect ratio w/h. As it is expected that the aspect ratio of the rectangular plate will typify the projected area configuration of various three-dimensional bodies, the aspect ratio is varied widely from 0.5 to 7.0. The transitional boundaries of Reh and h/δ in the 2-vortex, 4-vortex and 6-vortex systems for each aspect ratio decreased when w/h < 3.0, and increased when w/h ≥ 3.0 as w/h increased. The x-direction length of the main vortex position XV1/h was almost constant when w/h < 3.0, and decreased when w/h ≥ 3.0 as Reh increased. Then, the separation length r1/h increased when w/h < 3.0 and Reh < 1000, and became almost constant when w/h ≥ 3.0 and Reh ≥ 1000 as w/h and Reh increased. Moreover, the increase of r1/h is notably rapid when w/h < 3.0.展开更多
In this study, the unsteady behavior of necklace vortices formed in front of a square flat plate was experimentally investigated by flow visualization and PIV analysis by using a water channel. As a result, the neckla...In this study, the unsteady behavior of necklace vortices formed in front of a square flat plate was experimentally investigated by flow visualization and PIV analysis by using a water channel. As a result, the necklace vortices started to oscillate when the Reynolds number increased beyond approximately 2000. Then, an amalgamation behavior of the necklace vortices took place when the Reynolds number increased beyond approximately 2650. Furthermore, in the same Reynolds number range, a breakaway behavior appeared when the relative height of the square plate was beyond approximately h/δ = 4.0. The features of the necklace vortices behaviors in the oscillation, amalgamation and breakaway states were explained by observing the time-series image of path lines and by analyzing the frequency of velocity fluctuation.展开更多
THE NECKLACE is a drama script written by Maupassant,which is about Mathilde,who borrowed a diamond necklace from her friend to attend a party.Unexpectedly,the necklace was lost so she had to borrow money to buy a sim...THE NECKLACE is a drama script written by Maupassant,which is about Mathilde,who borrowed a diamond necklace from her friend to attend a party.Unexpectedly,the necklace was lost so she had to borrow money to buy a similar necklace and gave it back to her friend.She and her husband went through ten-years hard work.Finally,she was told the necklace was a fake one,which meant the ten years'suffering was in vain.Dell Hymes developed the SPEAKING Model to promote the analysis of discourse as a series of speech events and acts.The first letters of SPEAKING are used for speech contents and categories.In this paper,the SPEAKING Model is applied to the analysis of this drama script from the8main aspects.展开更多
This paper is an attempt to discuss the relationship between genre and the thematic progression. Through qualitative analysis of the short story Necklace of Maupassant, it is found that narrative texts always use the ...This paper is an attempt to discuss the relationship between genre and the thematic progression. Through qualitative analysis of the short story Necklace of Maupassant, it is found that narrative texts always use the linear theme pattern and the constant theme pattern, and sometimes the derived theme pattern and other patterns are also used to facilitate the text coherence and the plot development. Thematic progression in various fields has been studied extensively, but the analysis aims to short story is less than text coherence and other aspects. And there are some implications to teaching, writing, reading, and translation.展开更多
In this paper,a new infinite-dimensional necklace Lie algebra is studied and the left and right index arrays of a necklace word in necklace Lie algebra is first defined.Using the left and right index arrays,we divide ...In this paper,a new infinite-dimensional necklace Lie algebra is studied and the left and right index arrays of a necklace word in necklace Lie algebra is first defined.Using the left and right index arrays,we divide the necklace words into 5 classes.We discuss finite-dimensional Lie subalgebras of necklace Lie algebras intensively and prove that some subalgebras are isomorphism to simple Lie algebra sl(n).展开更多
Total embedding distributions have been known for only a few classes of graphs. In this paper the total embedding distributions of the cacti and the necklaces are obtained. Furthermore we obtain the total embedding di...Total embedding distributions have been known for only a few classes of graphs. In this paper the total embedding distributions of the cacti and the necklaces are obtained. Furthermore we obtain the total embedding distributions of all graphs with maximum genus 1 by using the method of this paper.展开更多
We study light propagation through cyclic arrays, composed by copies of a given PT-symmetric dimer, using a group theoretical approach and finite element modeling. The theoretical mode-coupling analysis suggests the u...We study light propagation through cyclic arrays, composed by copies of a given PT-symmetric dimer, using a group theoretical approach and finite element modeling. The theoretical mode-coupling analysis suggests the use of these devices as output port replicators where the dynamics is controlled by the impinging light field. This is confirmed in good agreement with finite element propagation in an experimentally feasible necklace of passive PT-symmetric dimers constructed from lossy and lossless waveguides.展开更多
In the excavated gold-threadedjade cloth of Dou Wan, the wife of thefirst Zhongshan emperor of WesternHan Dynasty, were scattered jadeornaments of varying styles. Thebiggest one among them, a 2.5 cm longjade dancer, d...In the excavated gold-threadedjade cloth of Dou Wan, the wife of thefirst Zhongshan emperor of WesternHan Dynasty, were scattered jadeornaments of varying styles. Thebiggest one among them, a 2.5 cm longjade dancer, demands attention in itsdelicacy. Slightly yellow in color,展开更多
The super-austenitic stainless steels are extensively utilized in the seamless tubes production for oil extraction industries. Due to the importance of thermo-mechanical processing in the production of these tubes, th...The super-austenitic stainless steels are extensively utilized in the seamless tubes production for oil extraction industries. Due to the importance of thermo-mechanical processing in the production of these tubes, the dynamic recrystallization （DRX） characteristics of a Cr-Ni super austenitic stainless steel （1.4563） were investigated in the present study. This was performed using the hot compression testing method in the temperature range of 950-1150℃ and the strain rate of 10^-3-10^-1 s^-1. The initiation and evolution of DRX were examined through microstructural analysis. The results indicated that the recrystallized grain formed a necklace type structure at the prior austenite grain boundaries at higher strain rates. In addition, DRX nucleation occurs by bulging and successive strain induced boundary migration （SIBM）.展开更多
De Bruijn sequences are highly important nonlinear shift register sequences. This paper presents a new algorithm for the generation of fc-ary de Bruijn sequences by juxtaposing the periodic reductions of the cycles. I...De Bruijn sequences are highly important nonlinear shift register sequences. This paper presents a new algorithm for the generation of fc-ary de Bruijn sequences by juxtaposing the periodic reductions of the cycles. Its each step produces a string of elements instead of one element. Hence the algorithm reduces the time of operation, and accelerates the speed of generation.展开更多
Actinide metallacycles are an emerging class of functional coordination assemblies,but multi-level assembly from metallacycle units toward hierarchical supramolecular structures are still rarely investigated.In this w...Actinide metallacycles are an emerging class of functional coordination assemblies,but multi-level assembly from metallacycle units toward hierarchical supramolecular structures are still rarely investigated.In this work,we put forward a novel supramolecular inclusion-based method through introducing two macrocyclic hosts,cucurbit[7]uril(CB[7])and cucurbit[8]uril(CB[8])to facilitate hierarchical assembly of uranyl metallacycles with higher complexity,and successfully prepare two different kinds of uranyl metallacycle-based complexes with intriguing hierarchical structures,a CB[7]-based four-member molecular necklace([4]MN)and a CB[8]-involved ring-in-ring supramolecular polymer chain.The results obtained here prove the feasibility of supramolecular inclusion for regulating coordination assembly of uranyl metallacycles and related hierarchical structures.It is believed that this method can be used to achieve the construction of actinide coordination assemblies with higher structural complexity.展开更多
文摘Various properties of a necklace vortex system formed around a rectangular plate standing vertically on a flat ground wall were investigated by visualizations produced by injecting fluorescent dye into a water channel flow. As a result, it was found that the necklace vortex pattern had three steady systems depending on the Reynolds number Reh, the relative height h/δ of the rectangular plate compared with the laminar boundary layer thickness and the aspect ratio w/h. As it is expected that the aspect ratio of the rectangular plate will typify the projected area configuration of various three-dimensional bodies, the aspect ratio is varied widely from 0.5 to 7.0. The transitional boundaries of Reh and h/δ in the 2-vortex, 4-vortex and 6-vortex systems for each aspect ratio decreased when w/h < 3.0, and increased when w/h ≥ 3.0 as w/h increased. The x-direction length of the main vortex position XV1/h was almost constant when w/h < 3.0, and decreased when w/h ≥ 3.0 as Reh increased. Then, the separation length r1/h increased when w/h < 3.0 and Reh < 1000, and became almost constant when w/h ≥ 3.0 and Reh ≥ 1000 as w/h and Reh increased. Moreover, the increase of r1/h is notably rapid when w/h < 3.0.
文摘In this study, the unsteady behavior of necklace vortices formed in front of a square flat plate was experimentally investigated by flow visualization and PIV analysis by using a water channel. As a result, the necklace vortices started to oscillate when the Reynolds number increased beyond approximately 2000. Then, an amalgamation behavior of the necklace vortices took place when the Reynolds number increased beyond approximately 2650. Furthermore, in the same Reynolds number range, a breakaway behavior appeared when the relative height of the square plate was beyond approximately h/δ = 4.0. The features of the necklace vortices behaviors in the oscillation, amalgamation and breakaway states were explained by observing the time-series image of path lines and by analyzing the frequency of velocity fluctuation.
文摘THE NECKLACE is a drama script written by Maupassant,which is about Mathilde,who borrowed a diamond necklace from her friend to attend a party.Unexpectedly,the necklace was lost so she had to borrow money to buy a similar necklace and gave it back to her friend.She and her husband went through ten-years hard work.Finally,she was told the necklace was a fake one,which meant the ten years'suffering was in vain.Dell Hymes developed the SPEAKING Model to promote the analysis of discourse as a series of speech events and acts.The first letters of SPEAKING are used for speech contents and categories.In this paper,the SPEAKING Model is applied to the analysis of this drama script from the8main aspects.
文摘This paper is an attempt to discuss the relationship between genre and the thematic progression. Through qualitative analysis of the short story Necklace of Maupassant, it is found that narrative texts always use the linear theme pattern and the constant theme pattern, and sometimes the derived theme pattern and other patterns are also used to facilitate the text coherence and the plot development. Thematic progression in various fields has been studied extensively, but the analysis aims to short story is less than text coherence and other aspects. And there are some implications to teaching, writing, reading, and translation.
文摘In this paper,a new infinite-dimensional necklace Lie algebra is studied and the left and right index arrays of a necklace word in necklace Lie algebra is first defined.Using the left and right index arrays,we divide the necklace words into 5 classes.We discuss finite-dimensional Lie subalgebras of necklace Lie algebras intensively and prove that some subalgebras are isomorphism to simple Lie algebra sl(n).
基金Supported by by NNSFC under Grant No. 60373030 and found of Beijing JiaoTong Univeristy under Grant No.2004SM054
文摘Total embedding distributions have been known for only a few classes of graphs. In this paper the total embedding distributions of the cacti and the necklaces are obtained. Furthermore we obtain the total embedding distributions of all graphs with maximum genus 1 by using the method of this paper.
基金Consejo Nacional de Ciencia y Tecnología(CONACYT)(Catedra Grupal#551,FORDECYT#290259)Red de Tecnologías Cuánticas
文摘We study light propagation through cyclic arrays, composed by copies of a given PT-symmetric dimer, using a group theoretical approach and finite element modeling. The theoretical mode-coupling analysis suggests the use of these devices as output port replicators where the dynamics is controlled by the impinging light field. This is confirmed in good agreement with finite element propagation in an experimentally feasible necklace of passive PT-symmetric dimers constructed from lossy and lossless waveguides.
文摘In the excavated gold-threadedjade cloth of Dou Wan, the wife of thefirst Zhongshan emperor of WesternHan Dynasty, were scattered jadeornaments of varying styles. Thebiggest one among them, a 2.5 cm longjade dancer, demands attention in itsdelicacy. Slightly yellow in color,
文摘The super-austenitic stainless steels are extensively utilized in the seamless tubes production for oil extraction industries. Due to the importance of thermo-mechanical processing in the production of these tubes, the dynamic recrystallization （DRX） characteristics of a Cr-Ni super austenitic stainless steel （1.4563） were investigated in the present study. This was performed using the hot compression testing method in the temperature range of 950-1150℃ and the strain rate of 10^-3-10^-1 s^-1. The initiation and evolution of DRX were examined through microstructural analysis. The results indicated that the recrystallized grain formed a necklace type structure at the prior austenite grain boundaries at higher strain rates. In addition, DRX nucleation occurs by bulging and successive strain induced boundary migration （SIBM）.
文摘De Bruijn sequences are highly important nonlinear shift register sequences. This paper presents a new algorithm for the generation of fc-ary de Bruijn sequences by juxtaposing the periodic reductions of the cycles. Its each step produces a string of elements instead of one element. Hence the algorithm reduces the time of operation, and accelerates the speed of generation.
基金support from the National Science Fund for Distinguished Young Scholars(No.21925603)the National Natural Science Foundation of China(Nos.22122609,22076186 and 22176191)。
文摘Actinide metallacycles are an emerging class of functional coordination assemblies,but multi-level assembly from metallacycle units toward hierarchical supramolecular structures are still rarely investigated.In this work,we put forward a novel supramolecular inclusion-based method through introducing two macrocyclic hosts,cucurbit[7]uril(CB[7])and cucurbit[8]uril(CB[8])to facilitate hierarchical assembly of uranyl metallacycles with higher complexity,and successfully prepare two different kinds of uranyl metallacycle-based complexes with intriguing hierarchical structures,a CB[7]-based four-member molecular necklace([4]MN)and a CB[8]-involved ring-in-ring supramolecular polymer chain.The results obtained here prove the feasibility of supramolecular inclusion for regulating coordination assembly of uranyl metallacycles and related hierarchical structures.It is believed that this method can be used to achieve the construction of actinide coordination assemblies with higher structural complexity.
