For a graph G and two positive integers j and k an m-L j k -edge-labeling of G is an assignment from the set 0 1 … m-to the edges such that adjacent edges receive labels that differ by at least j and edges at distanc...For a graph G and two positive integers j and k an m-L j k -edge-labeling of G is an assignment from the set 0 1 … m-to the edges such that adjacent edges receive labels that differ by at least j and edges at distance two receive labels that differ by at least k.Theλ′j k-number of G denoted byλ′j k G is the minimum integer m overall m-L j k -edge-labeling of G.The necklace is a specific type of Halin graph.The L 1 2 -edge-labeling of necklaces is studied and the lower and upper bounds on λ′1 2-number for necklaces are given.Also both the lower and upper bounds are attainable.展开更多
In this paper, we review recent progress in the understanding of a novel dislocation mechanism, named correlated necklace dislocations(CNDs), activated in highly oriented nanotwinned(NT) metals under monotonic and cyc...In this paper, we review recent progress in the understanding of a novel dislocation mechanism, named correlated necklace dislocations(CNDs), activated in highly oriented nanotwinned(NT) metals under monotonic and cyclic loading applied parallel to the twin boundaries(TBs). This mechanism was initially revealed to be responsible for the continuous strengthening behavior of NT metals when the TB spacing(λ) is reduced to around 1 nm. It was later found that the presence of a crack-like defect could trigger the operation of CNDs at much larger TB spacings. Most recently, atomistic modeling and experiments demonstrated a history-independent and stable cyclic response of highly oriented NT metals governed by CNDs formed in the NT structure under cyclic loading. CNDs move along the twin planes without directional lattice slip resistance, thus contributing to a symmetric cyclic response of the NT structure regardless of pre-strains imposed on the sample before cyclic loading. We conclude with potential research directions in the investigation of this unique deformation mechanism in highly oriented NT metals.展开更多
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
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 dement modeling. The theoretical mode-coupling analysis suggests the us...We study light propagation through cyclic arrays, composed by copies of a given PT-symmetric dimer, using a group theoretical approach and finite dement 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 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
Zero-energy modes localized at the ends of one-dimensional(1D)wires hold great potential as qubits for fault-tolerant quantum computing.However,all the candidates known to date exhibit a wave function that decays expo...Zero-energy modes localized at the ends of one-dimensional(1D)wires hold great potential as qubits for fault-tolerant quantum computing.However,all the candidates known to date exhibit a wave function that decays exponentially into the bulk and hybridizes with other nearby zero-modes,thus hampering their use for braiding operations.Here,we show that a quasi-1D diamond-necklace chain exhibits an unforeseen type of robust boundary state,namely compact localized zero-energy modes that do not decay into the bulk.We find that this state emerges due to the presence of a latent symmetry in the system.We experimentally realize the diamond-necklace chain in an electronic quantum simulator setup.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
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
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
As the midday sun beats down on Shenzhen,Guangdong Province,a fascinating scene unfolds outside the glass-and-steel office towers that house China’s tech elite.Delivery riders pulling up on their electric scooters fi...As the midday sun beats down on Shenzhen,Guangdong Province,a fascinating scene unfolds outside the glass-and-steel office towers that house China’s tech elite.Delivery riders pulling up on their electric scooters find themselves surrounded not by the usual office workers,but by groups of eager children mostly aged 10 to 14,each sporting a QR code necklace like a badge of honor.展开更多
基金The National Natural Science Foundation of China(No.10971025,10901035)
文摘For a graph G and two positive integers j and k an m-L j k -edge-labeling of G is an assignment from the set 0 1 … m-to the edges such that adjacent edges receive labels that differ by at least j and edges at distance two receive labels that differ by at least k.Theλ′j k-number of G denoted byλ′j k G is the minimum integer m overall m-L j k -edge-labeling of G.The necklace is a specific type of Halin graph.The L 1 2 -edge-labeling of necklaces is studied and the lower and upper bounds on λ′1 2-number for necklaces are given.Also both the lower and upper bounds are attainable.
基金Project supported by the National Natural Science Foundation of China(No.11902289)the Hundred Talents Program of Zhejiang University,China。
文摘In this paper, we review recent progress in the understanding of a novel dislocation mechanism, named correlated necklace dislocations(CNDs), activated in highly oriented nanotwinned(NT) metals under monotonic and cyclic loading applied parallel to the twin boundaries(TBs). This mechanism was initially revealed to be responsible for the continuous strengthening behavior of NT metals when the TB spacing(λ) is reduced to around 1 nm. It was later found that the presence of a crack-like defect could trigger the operation of CNDs at much larger TB spacings. Most recently, atomistic modeling and experiments demonstrated a history-independent and stable cyclic response of highly oriented NT metals governed by CNDs formed in the NT structure under cyclic loading. CNDs move along the twin planes without directional lattice slip resistance, thus contributing to a symmetric cyclic response of the NT structure regardless of pre-strains imposed on the sample before cyclic loading. We conclude with potential research directions in the investigation of this unique deformation mechanism in highly oriented NT metals.
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.
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 dement 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 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financial support from the European Research Council(Horizon 2020“FRACTAL”,865570)the Dutch Research Council(grant 16PR3245)+2 种基金the research program“Materials for the Quantum Age”(QuMat)for financial supportThis program(registration number 024.005.006)is part of the Gravitation program financed by the Dutch Ministry of Education,Culture and Science(OCW)funding provided by Shanghai Jiao Tong University.
文摘Zero-energy modes localized at the ends of one-dimensional(1D)wires hold great potential as qubits for fault-tolerant quantum computing.However,all the candidates known to date exhibit a wave function that decays exponentially into the bulk and hybridizes with other nearby zero-modes,thus hampering their use for braiding operations.Here,we show that a quasi-1D diamond-necklace chain exhibits an unforeseen type of robust boundary state,namely compact localized zero-energy modes that do not decay into the bulk.We find that this state emerges due to the presence of a latent symmetry in the system.We experimentally realize the diamond-necklace chain in an electronic quantum simulator setup.
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）.
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.
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.
文摘As the midday sun beats down on Shenzhen,Guangdong Province,a fascinating scene unfolds outside the glass-and-steel office towers that house China’s tech elite.Delivery riders pulling up on their electric scooters find themselves surrounded not by the usual office workers,but by groups of eager children mostly aged 10 to 14,each sporting a QR code necklace like a badge of honor.
