Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and...Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and connection mechanisms of attraction networks is important for understanding the linkages between attractions and even the future destination planning.This paper uses geotagging data to compare the links between attractions in Beijing,China during four different periods:the pre-Olympic period(2004–2007),the Olympic Games and subsequent‘heat period’(2008–2013),the post-Olympic period(2014–2019),and the COVID-19(Corona Virus Disease 2019)pandemic period(2020–2021).The aim is to better understand the evolution and patterns of attraction networks at different scales in Beijing and to provide insights for tourism planning in the destination.The results show that the macro,meso-,and microscales network characteristics of attraction networks have inherent logical relationships that can explain the commonalities and differences in the development process of tourism networks.The macroscale attraction network degree Matthew effect is significant in the four different periods and exhibits a morphological monocentric structure,suggesting that new entrants are more likely to be associated with attractions that already have high value.The mesoscale links attractions according to the common purpose of tourists,and the results of the community segmentation of the attraction networks in the four different periods suggest that the functional polycentric structure describes their clustering effect,and the weak links between clusters result from attractions bound by incomplete information and distance,and the functional polycentric structure with a generally more efficient network of clusters.The pattern structure at the microscale reveals the topological transformation relationship of the regional collaboration pattern,and the attraction network structure in the four different periods has a very similar importance profile structure suggesting that the attraction network has the same construction rules and evolution mechanism,which aids in understanding the attraction network pattern at both macro and micro scales.Important approaches and practical implications for planners and managers are presented.展开更多
The focus of this study was to examine how different factors including gender of the person on Snapchat and Snapchat filter types (no filter vs. pretty filter vs. frown filter vs. dog filter vs. sponsored filter) infl...The focus of this study was to examine how different factors including gender of the person on Snapchat and Snapchat filter types (no filter vs. pretty filter vs. frown filter vs. dog filter vs. sponsored filter) influence social and physical attraction perception of a person. An experiment manipulating both factors was conducted (N = 226). Results showed female on Snapchat was rated significantly higher on both social and physical attraction than their male counterparts. The use of different types of Snapchat filters had a significant effect on social attraction, but not on physical attraction. Moreover, there was a significant interaction effect between gender of the person on Snapchat and the types of Snapchat filter used on the social attraction rating.展开更多
The phenomenon of electrical attraction and repulsion between charged particles is well known, and described mathematically by Coulomb’s Law, yet until now there has been no explanation for why this occurs. There has...The phenomenon of electrical attraction and repulsion between charged particles is well known, and described mathematically by Coulomb’s Law, yet until now there has been no explanation for why this occurs. There has been no mechanistic explanation that reveals what causes the charged particles to accelerate, either towards or away from each other. This paper gives a detailed explanation of the phenomena of electrical attraction and repulsion based on my previous work that determined the exact wave-function solutions for both the Electron and the Positron. It is revealed that the effects are caused by wave interactions between the wave functions that result in Electromagnetic reflections of parts of the particle’s wave functions, causing a change in their momenta.展开更多
The mechanics of Coulomb attraction and repulsion between charged particles are not currently understood but can be explained using a photon-pair aether. A spin-2 photon pair with no net E or B fields can freely penet...The mechanics of Coulomb attraction and repulsion between charged particles are not currently understood but can be explained using a photon-pair aether. A spin-2 photon pair with no net E or B fields can freely penetrate deep into matter. It may collide with a charged particle and be transformed through the interaction into a spin-0 photon pair. This outflow of spin-0 photon pairs forms a homogeneous (+E) or (−E) electrostatic field around the particle, depending on its charge. Charged particles in the vicinity of each other experience an asymmetry in the incoming field, from which attraction or repulsion arises. Repulsion or attraction is understood as the transfer of momentum from photons to particles, which results in the appearance of a force.展开更多
Attracting foreign capital is a key pillar of China’s reform and opening up policy,and foreign-funded enterprises are an important component of China’s economy.Currently,China is taking steps to further boost its at...Attracting foreign capital is a key pillar of China’s reform and opening up policy,and foreign-funded enterprises are an important component of China’s economy.Currently,China is taking steps to further boost its attractiveness as a foreign direct investment(FDI)destination in order to seek more foreign capital.展开更多
Through analyzing relevant documents,connotations of rural landscape attractiveness were introduced,and existing problems of present rural landscapes elaborated.It was proposed that rural tourism of China has no effec...Through analyzing relevant documents,connotations of rural landscape attractiveness were introduced,and existing problems of present rural landscapes elaborated.It was proposed that rural tourism of China has no effective strategic planning,distinctive characteristics of landscape products,or efficient marketing of rural landscape resources.Influencing factors of rural landscape attractiveness were summarized,and suggestions were given to improve the attractiveness by combining with actual conditions of China.Moreover,it was stressed that favorable rural landscape images should be created,and more efforts devoted in safeguarding native-soil cultural landscapes and exploring tourist market of rural landscape resources.The study was to provide useful references for the new countryside construction of China.展开更多
Enormous progresses to understand the jamming transition have been driven via simulating purely repulsive particles which were somehow idealized in the past two decades. While the attractive systems are both theoretic...Enormous progresses to understand the jamming transition have been driven via simulating purely repulsive particles which were somehow idealized in the past two decades. While the attractive systems are both theoretical and practical compared with repulsive systems. By studying the statistics of rigid clusters, we find that the critical packing fraction φ_(c) varies linearly with attraction μ for different system sizes when the range of attraction is short. While for systems with long-range attractions, however, the slope of φ_(c) appears significantly different, which means that there are two distinct jamming scenarios. In this paper, we focus our main attention on short-range attractions scenario and define a new quantity named "short-range attraction susceptibility" χ_(p), which describes the degree of response of the probability of finding jammed states pjto short-range attraction strength μ. Our central results are that χ_(p) diverges in the thermodynamic limit as χ_(p) ∝|φ-φ_(c)^(∞)|^(-γ_(p)), where φ_(c)^(∞) is the packing fraction at the jamming transition for the infinite system in the absence of attraction. χ_(p) obeys scaling collapse with a scaling function in both two and three dimensions, illuminating that the jamming transition can be considered as a phase transition as proposed in previous work.展开更多
[Objective] The paper aims to study the attractive effects of 12 Chinese medicinal herbs on Scophthalmus maximus juvenile.[Method] We took 200 Scophthalmus maximus with the average body length of 3 cm,average weight o...[Objective] The paper aims to study the attractive effects of 12 Chinese medicinal herbs on Scophthalmus maximus juvenile.[Method] We took 200 Scophthalmus maximus with the average body length of 3 cm,average weight of 1 g and 60 days of age as the research object,and 12 Chinese medicinal herbs as feed attractants were selected,including Cloves,Cinnamon,Star anise,Kaempferol,Mint,Coptis,Phellodendron,skullcap,Gardenia,Sophora flavescens,Mume,Myrobalan meat were selected.The amount added to the basic diet was 2‰..The times of turbot juveniles going into each inducing room and the times of turbot juveniles biting the feed ball were recorded by maze experiments.Inducing effects of the Chinese herbal medicines were analyzed.[Result] The results showed that the attractant effect of Mume,Gardenia,Scutellaria and kaempferol had the significantly inducing effect on Scophthalmus maximus juvenile.And 2‰ Gardenia,5‰ Matrine,5‰ Scutellaria and 2‰ Kaempferol have the best attractant effects.In compound experients,the attractive effect of mixture of 2‰ matrine and gardenia on Scophthalmus maximus was the best.[Conclusion] The attractive effect on Scophthalmus maximus has something to do with the kind and concentration of Chinese medicinal herbs.展开更多
Modeling research and empirical study on the attraction of tourism destinations were conducted from 6 aspects,i.e.quality and scale of tourism resources,economic environment of tourism destinations,policy environment,...Modeling research and empirical study on the attraction of tourism destinations were conducted from 6 aspects,i.e.quality and scale of tourism resources,economic environment of tourism destinations,policy environment,accessibility,income level of tourist source areas as well as distance between tourist source area and tourism destination.展开更多
Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjectur...Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjecture forward.展开更多
Through survey of visitors,relevant data had been acquired.By aid of factor analysis method,computation model of comprehensive tourist attractiveness of ancient villages and towns was established,which had certain the...Through survey of visitors,relevant data had been acquired.By aid of factor analysis method,computation model of comprehensive tourist attractiveness of ancient villages and towns was established,which had certain theoretical and practical guidance value to rural tourism resources development and market development.展开更多
In order to improve the management level of heritage tourist attractions and achieve their sustainable development,a comparative study has been conducted on the management mode of heritage tourist attractions in China...In order to improve the management level of heritage tourist attractions and achieve their sustainable development,a comparative study has been conducted on the management mode of heritage tourist attractions in China and foreign countries from the perspective of management foundation,management objects and management resources.Then,suggestions have been proposed from the ideology and supervision mechanism,including improving ideology,upgrading management system,completing supervision mechanism and adopting international management mode.Particularly,the paper has pointed out that it should find the best management mode based on different social and economic backgrounds of the countries of heritage tourist attractions.展开更多
The dynamic behavior of discrete-time cellular neural networks(DTCNN), which is strict with zero threshold value, is mainly studied in asynchronous mode and in synchronous mode. In general, a k-attractor of DTCNN is n...The dynamic behavior of discrete-time cellular neural networks(DTCNN), which is strict with zero threshold value, is mainly studied in asynchronous mode and in synchronous mode. In general, a k-attractor of DTCNN is not a convergent point. But in this paper, it is proved that a k-attractor is a convergent point if the strict DTCNN satisfies some conditions. The attraction basin of the strict DTCNN is studied, one example is given to illustrate the previous conclusions to be wrong, and several results are presented. The obtained results on k-attractor and attraction basin not only correct the previous results, but also provide a theoretical foundation of performance analysis and new applications of the DTCNN.展开更多
To improve the complexity of chaotic signals,in this paper we first put forward a new three-dimensional quadratic fractional-order multi-scroll hidden chaotic system,then we use the Adomian decomposition algorithm to ...To improve the complexity of chaotic signals,in this paper we first put forward a new three-dimensional quadratic fractional-order multi-scroll hidden chaotic system,then we use the Adomian decomposition algorithm to solve the proposed fractional-order chaotic system and obtain the chaotic phase diagrams of different orders,as well as the Lyaponov exponent spectrum,bifurcation diagram,and SE complexity of the 0.99-order system.In the process of analyzing the system,we find that the system possesses the dynamic behaviors of hidden attractors and hidden bifurcations.Next,we also propose a method of using the Lyapunov exponents to describe the basins of attraction of the chaotic system in the matlab environment for the first time,and obtain the basins of attraction under different order conditions.Finally,we construct an analog circuit system of the fractional-order chaotic system by using an equivalent circuit module of the fractional-order integral operators,thus realizing the 0.9-order multi-scroll hidden chaotic attractors.展开更多
This work studies the stability and hidden dynamics of the nonlinear hydro-turbine governing system with an output limiting link,and propose a new six-dimensional system,which exhibits some hidden attractors.The param...This work studies the stability and hidden dynamics of the nonlinear hydro-turbine governing system with an output limiting link,and propose a new six-dimensional system,which exhibits some hidden attractors.The parameter switching algorithm is used to numerically study the dynamic behaviors of the system.Moreover,it is investigated that for some parameters the system with a stable equilibrium point can generate strange hidden attractors.A self-excited attractor with the change of its parameters is also recognized.In addition,numerical simulations are carried out to analyze the dynamic behaviors of the proposed system by using the Lyapunov exponent spectra,Lyapunov dimensions,bifurcation diagrams,phase space orbits,and basins of attraction.Consequently,the findings in this work show that the basins of hidden attractors are tiny for which the standard computational procedure for localization is unavailable.These simulation results are conducive to better understanding of hidden chaotic attractors in higher-dimensional dynamical systems,and are also of great significance in revealing chaotic oscillations such as uncontrolled speed adjustment in the operation of hydropower station due to small changes of initial values.展开更多
In this paper, we provide a new approach to study the geometry of attractor. By applying category, we investigate the relationship between attractor and its attraction basin. In a complete metric space, we prove that ...In this paper, we provide a new approach to study the geometry of attractor. By applying category, we investigate the relationship between attractor and its attraction basin. In a complete metric space, we prove that the categories of attractor and its attraction basin are always equal. Then we apply this result to both autonomous and non-autonomous systems, and obtain a number of corresponding results.展开更多
Arthur Miller's masterpiece Death of a Salesman is a very clear attack on the American success myth.The most dominant theme running throughout the play is Willy Loman's philosophy of personal attractiveness an...Arthur Miller's masterpiece Death of a Salesman is a very clear attack on the American success myth.The most dominant theme running throughout the play is Willy Loman's philosophy of personal attractiveness and its doomed futility.This philosophy not only brings failure to Willy's career but also destruction to Willy's family members.展开更多
The tea geometridEctropis obliquais one of the most serious leaf-feeding insect pests in tea (Camelia sinensis) in East Asia. Although several volatile chemicals emitted from tea plants have been reported to be attr...The tea geometridEctropis obliquais one of the most serious leaf-feeding insect pests in tea (Camelia sinensis) in East Asia. Although several volatile chemicals emitted from tea plants have been reported to be attractive toE. obliqua moths, no synthetic attractants for E. obliqua moths have been developed. By measuring the behavioral responses of the moth to a series of chemicals in the lab, we found that a blend containing a ternary mixture containing (Z)-3-hexenal, (Z)-3-hexenyl hexanoate and benzyl alcohol clearly attracted toE. obliqua moths of both sex and that (Z)-3-hexenyl acetate could enhance the attractiveness of the ternary blend. Moreover, we found that the volatiles emitted from the plant-E. obliqua larva com-plex have the same attractiveness as: 1) the blend of volatiles containing the ternary mixture and 2) the blend containing (Z)-3-hexenyl acetate plus the ternary mixture to both male and female moths. In a ifeld bioassay, more male moths were observed on traps that were baited with the blend containing (Z)-3-hexenyl acetate plus the ternary mixture than on control traps. Our study raises the tantalizing possibility that synthetic blends could be deployed as attractants for pests in the ifeld.展开更多
The multicolored Asian lady beetle, Harmonia axyridis(Coleoptera: Coccinellidae), is a common generalist predator in China and is occasionally found gathering on the Chinese pagoda tree, Sophora japonica, in summer. I...The multicolored Asian lady beetle, Harmonia axyridis(Coleoptera: Coccinellidae), is a common generalist predator in China and is occasionally found gathering on the Chinese pagoda tree, Sophora japonica, in summer. In a field investigation, we found that H. axyridis adults preferred S. japonica during its flowering period even though their optimal prey(aphid) is absent at this time. In addition, male and female adults were attracted to S. japonica flowers to a similar extent in a Y-tube olfactometer assay. Using coupled gas chromatography-electroantennogram detection(GC-EAD), we identified a flower odor component(nonanal) that elicited a significant electrophysiological response in H. axyridis. Electroantennogram(EAG) dose-dependent responses revealed that the amplitude of the adult beetle's EAG response increased with increasing concentration of nonanal, peaking at 10 mg mL^(–1). In Y-tube olfactometer behavioral tests, H. axyridis adults preferred a 10 mg mL^(–1) nonanal source over a 100 mg mL^(–1) diluent. Under field conditions, the adults were significantly attracted to both concentrations(10 and 100 mg mL^(–1)), and high concentrations generally had greater attraction. All these results suggest that nonanal, a volatile compound of S. japonica flowers, greatly attracts H. axyridis adults. This study provides a basis for the development of synthetic attractants of H. axyridis, with the potential to promote biocontrol services of this generalist predator in the native area(e.g., China) and to suppress its population by mass trapping in its invasive areas.展开更多
Chemotaxis to water-soluble attractants is mainly controlled by ASE sensory neuron whose specification is regulated by che-1 in Caenorhabditis elegans. Our data suggested that exposure to high concentrations of metals...Chemotaxis to water-soluble attractants is mainly controlled by ASE sensory neuron whose specification is regulated by che-1 in Caenorhabditis elegans. Our data suggested that exposure to high concentrations of metals, such as Pb, Cu, Ag, and Cr, would result in severe defects of chemotaxis to water-soluble attractants of NaCl, cAMP, and biotin. Moreover, the morphology of ASE neuron structures as observed by relative fluorescent intensities and relative size of fluorescent puncta of cell bodies, relative lengths of sensory endings in ASE neurons, and the expression patterns of che-1 were obviously altered in metal exposed animals when they meanwhile exhibited obvious chemotaxis defects to water-soluble attractants. In addition, the dendrite morphology could be noticeably changed in animals exposed to 150 μmol/L of Pb, Cu, and Ag. Furthermore, we observed significant decreases of chemotaxis to water-soluble attractants in Pb exposed che-1 mutant at concentrations more than 2.5 μmol/L, and in Cu, Ag, and Cr exposed che-1 mutant at concentrations more than 50 μmol/L. Therefore, impairment of the ASE neuron structures and functions may largely contribute to the appearance of chemotaxis defects to water-soluble attractants in metal exposed nematodes.展开更多
基金Under the auspices of the National Natural Science Foundation of China(No.41971202)the National Natural Science Foundation of China(No.42201181)the Fundamental research funding targets for central universities(No.2412022QD002)。
文摘Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and connection mechanisms of attraction networks is important for understanding the linkages between attractions and even the future destination planning.This paper uses geotagging data to compare the links between attractions in Beijing,China during four different periods:the pre-Olympic period(2004–2007),the Olympic Games and subsequent‘heat period’(2008–2013),the post-Olympic period(2014–2019),and the COVID-19(Corona Virus Disease 2019)pandemic period(2020–2021).The aim is to better understand the evolution and patterns of attraction networks at different scales in Beijing and to provide insights for tourism planning in the destination.The results show that the macro,meso-,and microscales network characteristics of attraction networks have inherent logical relationships that can explain the commonalities and differences in the development process of tourism networks.The macroscale attraction network degree Matthew effect is significant in the four different periods and exhibits a morphological monocentric structure,suggesting that new entrants are more likely to be associated with attractions that already have high value.The mesoscale links attractions according to the common purpose of tourists,and the results of the community segmentation of the attraction networks in the four different periods suggest that the functional polycentric structure describes their clustering effect,and the weak links between clusters result from attractions bound by incomplete information and distance,and the functional polycentric structure with a generally more efficient network of clusters.The pattern structure at the microscale reveals the topological transformation relationship of the regional collaboration pattern,and the attraction network structure in the four different periods has a very similar importance profile structure suggesting that the attraction network has the same construction rules and evolution mechanism,which aids in understanding the attraction network pattern at both macro and micro scales.Important approaches and practical implications for planners and managers are presented.
文摘The focus of this study was to examine how different factors including gender of the person on Snapchat and Snapchat filter types (no filter vs. pretty filter vs. frown filter vs. dog filter vs. sponsored filter) influence social and physical attraction perception of a person. An experiment manipulating both factors was conducted (N = 226). Results showed female on Snapchat was rated significantly higher on both social and physical attraction than their male counterparts. The use of different types of Snapchat filters had a significant effect on social attraction, but not on physical attraction. Moreover, there was a significant interaction effect between gender of the person on Snapchat and the types of Snapchat filter used on the social attraction rating.
文摘The phenomenon of electrical attraction and repulsion between charged particles is well known, and described mathematically by Coulomb’s Law, yet until now there has been no explanation for why this occurs. There has been no mechanistic explanation that reveals what causes the charged particles to accelerate, either towards or away from each other. This paper gives a detailed explanation of the phenomena of electrical attraction and repulsion based on my previous work that determined the exact wave-function solutions for both the Electron and the Positron. It is revealed that the effects are caused by wave interactions between the wave functions that result in Electromagnetic reflections of parts of the particle’s wave functions, causing a change in their momenta.
文摘The mechanics of Coulomb attraction and repulsion between charged particles are not currently understood but can be explained using a photon-pair aether. A spin-2 photon pair with no net E or B fields can freely penetrate deep into matter. It may collide with a charged particle and be transformed through the interaction into a spin-0 photon pair. This outflow of spin-0 photon pairs forms a homogeneous (+E) or (−E) electrostatic field around the particle, depending on its charge. Charged particles in the vicinity of each other experience an asymmetry in the incoming field, from which attraction or repulsion arises. Repulsion or attraction is understood as the transfer of momentum from photons to particles, which results in the appearance of a force.
文摘Attracting foreign capital is a key pillar of China’s reform and opening up policy,and foreign-funded enterprises are an important component of China’s economy.Currently,China is taking steps to further boost its attractiveness as a foreign direct investment(FDI)destination in order to seek more foreign capital.
文摘Through analyzing relevant documents,connotations of rural landscape attractiveness were introduced,and existing problems of present rural landscapes elaborated.It was proposed that rural tourism of China has no effective strategic planning,distinctive characteristics of landscape products,or efficient marketing of rural landscape resources.Influencing factors of rural landscape attractiveness were summarized,and suggestions were given to improve the attractiveness by combining with actual conditions of China.Moreover,it was stressed that favorable rural landscape images should be created,and more efforts devoted in safeguarding native-soil cultural landscapes and exploring tourist market of rural landscape resources.The study was to provide useful references for the new countryside construction of China.
基金supported by the National Natural Science Foundation of China (Grant No. 11702289)Key Core Technology and Generic Technology Research and Development Project of Shanxi Province,China (Grant No. 2020XXX013)the National Key Research and Development Project of China。
文摘Enormous progresses to understand the jamming transition have been driven via simulating purely repulsive particles which were somehow idealized in the past two decades. While the attractive systems are both theoretical and practical compared with repulsive systems. By studying the statistics of rigid clusters, we find that the critical packing fraction φ_(c) varies linearly with attraction μ for different system sizes when the range of attraction is short. While for systems with long-range attractions, however, the slope of φ_(c) appears significantly different, which means that there are two distinct jamming scenarios. In this paper, we focus our main attention on short-range attractions scenario and define a new quantity named "short-range attraction susceptibility" χ_(p), which describes the degree of response of the probability of finding jammed states pjto short-range attraction strength μ. Our central results are that χ_(p) diverges in the thermodynamic limit as χ_(p) ∝|φ-φ_(c)^(∞)|^(-γ_(p)), where φ_(c)^(∞) is the packing fraction at the jamming transition for the infinite system in the absence of attraction. χ_(p) obeys scaling collapse with a scaling function in both two and three dimensions, illuminating that the jamming transition can be considered as a phase transition as proposed in previous work.
文摘[Objective] The paper aims to study the attractive effects of 12 Chinese medicinal herbs on Scophthalmus maximus juvenile.[Method] We took 200 Scophthalmus maximus with the average body length of 3 cm,average weight of 1 g and 60 days of age as the research object,and 12 Chinese medicinal herbs as feed attractants were selected,including Cloves,Cinnamon,Star anise,Kaempferol,Mint,Coptis,Phellodendron,skullcap,Gardenia,Sophora flavescens,Mume,Myrobalan meat were selected.The amount added to the basic diet was 2‰..The times of turbot juveniles going into each inducing room and the times of turbot juveniles biting the feed ball were recorded by maze experiments.Inducing effects of the Chinese herbal medicines were analyzed.[Result] The results showed that the attractant effect of Mume,Gardenia,Scutellaria and kaempferol had the significantly inducing effect on Scophthalmus maximus juvenile.And 2‰ Gardenia,5‰ Matrine,5‰ Scutellaria and 2‰ Kaempferol have the best attractant effects.In compound experients,the attractive effect of mixture of 2‰ matrine and gardenia on Scophthalmus maximus was the best.[Conclusion] The attractive effect on Scophthalmus maximus has something to do with the kind and concentration of Chinese medicinal herbs.
文摘Modeling research and empirical study on the attraction of tourism destinations were conducted from 6 aspects,i.e.quality and scale of tourism resources,economic environment of tourism destinations,policy environment,accessibility,income level of tourist source areas as well as distance between tourist source area and tourism destination.
文摘Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjecture forward.
基金Supported by Research Project of Guilin College of Aerospace Technology (X09S024)~~
文摘Through survey of visitors,relevant data had been acquired.By aid of factor analysis method,computation model of comprehensive tourist attractiveness of ancient villages and towns was established,which had certain theoretical and practical guidance value to rural tourism resources development and market development.
文摘In order to improve the management level of heritage tourist attractions and achieve their sustainable development,a comparative study has been conducted on the management mode of heritage tourist attractions in China and foreign countries from the perspective of management foundation,management objects and management resources.Then,suggestions have been proposed from the ideology and supervision mechanism,including improving ideology,upgrading management system,completing supervision mechanism and adopting international management mode.Particularly,the paper has pointed out that it should find the best management mode based on different social and economic backgrounds of the countries of heritage tourist attractions.
文摘The dynamic behavior of discrete-time cellular neural networks(DTCNN), which is strict with zero threshold value, is mainly studied in asynchronous mode and in synchronous mode. In general, a k-attractor of DTCNN is not a convergent point. But in this paper, it is proved that a k-attractor is a convergent point if the strict DTCNN satisfies some conditions. The attraction basin of the strict DTCNN is studied, one example is given to illustrate the previous conclusions to be wrong, and several results are presented. The obtained results on k-attractor and attraction basin not only correct the previous results, but also provide a theoretical foundation of performance analysis and new applications of the DTCNN.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61561022 and 61672226)。
文摘To improve the complexity of chaotic signals,in this paper we first put forward a new three-dimensional quadratic fractional-order multi-scroll hidden chaotic system,then we use the Adomian decomposition algorithm to solve the proposed fractional-order chaotic system and obtain the chaotic phase diagrams of different orders,as well as the Lyaponov exponent spectrum,bifurcation diagram,and SE complexity of the 0.99-order system.In the process of analyzing the system,we find that the system possesses the dynamic behaviors of hidden attractors and hidden bifurcations.Next,we also propose a method of using the Lyapunov exponents to describe the basins of attraction of the chaotic system in the matlab environment for the first time,and obtain the basins of attraction under different order conditions.Finally,we construct an analog circuit system of the fractional-order chaotic system by using an equivalent circuit module of the fractional-order integral operators,thus realizing the 0.9-order multi-scroll hidden chaotic attractors.
基金the Fundamental Research Funds for the Northwest A&F University(Grant No./Z1090220172)the Scientific Research Foundation of the Natural Science Foundation of Shaanxi Province,China(Grant No.2019JLP-24)+1 种基金the Shaanxi Province Innovation Talent Promotion PlanScience and Technology Innovation Team,China(Grant No.2020TD-025)the Water Conservancy Science and Technology Program of Shaanxi Province,China(Grant No.2018slkj-9)。
文摘This work studies the stability and hidden dynamics of the nonlinear hydro-turbine governing system with an output limiting link,and propose a new six-dimensional system,which exhibits some hidden attractors.The parameter switching algorithm is used to numerically study the dynamic behaviors of the system.Moreover,it is investigated that for some parameters the system with a stable equilibrium point can generate strange hidden attractors.A self-excited attractor with the change of its parameters is also recognized.In addition,numerical simulations are carried out to analyze the dynamic behaviors of the proposed system by using the Lyapunov exponent spectra,Lyapunov dimensions,bifurcation diagrams,phase space orbits,and basins of attraction.Consequently,the findings in this work show that the basins of hidden attractors are tiny for which the standard computational procedure for localization is unavailable.These simulation results are conducive to better understanding of hidden chaotic attractors in higher-dimensional dynamical systems,and are also of great significance in revealing chaotic oscillations such as uncontrolled speed adjustment in the operation of hydropower station due to small changes of initial values.
文摘In this paper, we provide a new approach to study the geometry of attractor. By applying category, we investigate the relationship between attractor and its attraction basin. In a complete metric space, we prove that the categories of attractor and its attraction basin are always equal. Then we apply this result to both autonomous and non-autonomous systems, and obtain a number of corresponding results.
文摘Arthur Miller's masterpiece Death of a Salesman is a very clear attack on the American success myth.The most dominant theme running throughout the play is Willy Loman's philosophy of personal attractiveness and its doomed futility.This philosophy not only brings failure to Willy's career but also destruction to Willy's family members.
基金sponsored by the Special Fund for Agro-scientific Research in the Public Interest, China (201403030)the National Basic Research Program of China (2012CB114104)+1 种基金the National Natural Science Foundation of China (31272053)the Division of Science and Technology of Zhejiang Province, China (2015C32081)
文摘The tea geometridEctropis obliquais one of the most serious leaf-feeding insect pests in tea (Camelia sinensis) in East Asia. Although several volatile chemicals emitted from tea plants have been reported to be attractive toE. obliqua moths, no synthetic attractants for E. obliqua moths have been developed. By measuring the behavioral responses of the moth to a series of chemicals in the lab, we found that a blend containing a ternary mixture containing (Z)-3-hexenal, (Z)-3-hexenyl hexanoate and benzyl alcohol clearly attracted toE. obliqua moths of both sex and that (Z)-3-hexenyl acetate could enhance the attractiveness of the ternary blend. Moreover, we found that the volatiles emitted from the plant-E. obliqua larva com-plex have the same attractiveness as: 1) the blend of volatiles containing the ternary mixture and 2) the blend containing (Z)-3-hexenyl acetate plus the ternary mixture to both male and female moths. In a ifeld bioassay, more male moths were observed on traps that were baited with the blend containing (Z)-3-hexenyl acetate plus the ternary mixture than on control traps. Our study raises the tantalizing possibility that synthetic blends could be deployed as attractants for pests in the ifeld.
基金financially supported by the National Key Research and Development Program of China(2017YFD0201900)the National Natural Science Foundation of China(31621064)the earmarked fund for China Agriculture Research System(CARS-15-19)
文摘The multicolored Asian lady beetle, Harmonia axyridis(Coleoptera: Coccinellidae), is a common generalist predator in China and is occasionally found gathering on the Chinese pagoda tree, Sophora japonica, in summer. In a field investigation, we found that H. axyridis adults preferred S. japonica during its flowering period even though their optimal prey(aphid) is absent at this time. In addition, male and female adults were attracted to S. japonica flowers to a similar extent in a Y-tube olfactometer assay. Using coupled gas chromatography-electroantennogram detection(GC-EAD), we identified a flower odor component(nonanal) that elicited a significant electrophysiological response in H. axyridis. Electroantennogram(EAG) dose-dependent responses revealed that the amplitude of the adult beetle's EAG response increased with increasing concentration of nonanal, peaking at 10 mg mL^(–1). In Y-tube olfactometer behavioral tests, H. axyridis adults preferred a 10 mg mL^(–1) nonanal source over a 100 mg mL^(–1) diluent. Under field conditions, the adults were significantly attracted to both concentrations(10 and 100 mg mL^(–1)), and high concentrations generally had greater attraction. All these results suggest that nonanal, a volatile compound of S. japonica flowers, greatly attracts H. axyridis adults. This study provides a basis for the development of synthetic attractants of H. axyridis, with the potential to promote biocontrol services of this generalist predator in the native area(e.g., China) and to suppress its population by mass trapping in its invasive areas.
基金supported by the National Natural Science Foundation of China (No. 30771113, 30870810)the Program for New Century Excellent Talents in Universityprovided by the Caenorhabdits Genetics Center (funded by the NIH National Center for Research Resource, USA).
文摘Chemotaxis to water-soluble attractants is mainly controlled by ASE sensory neuron whose specification is regulated by che-1 in Caenorhabditis elegans. Our data suggested that exposure to high concentrations of metals, such as Pb, Cu, Ag, and Cr, would result in severe defects of chemotaxis to water-soluble attractants of NaCl, cAMP, and biotin. Moreover, the morphology of ASE neuron structures as observed by relative fluorescent intensities and relative size of fluorescent puncta of cell bodies, relative lengths of sensory endings in ASE neurons, and the expression patterns of che-1 were obviously altered in metal exposed animals when they meanwhile exhibited obvious chemotaxis defects to water-soluble attractants. In addition, the dendrite morphology could be noticeably changed in animals exposed to 150 μmol/L of Pb, Cu, and Ag. Furthermore, we observed significant decreases of chemotaxis to water-soluble attractants in Pb exposed che-1 mutant at concentrations more than 2.5 μmol/L, and in Cu, Ag, and Cr exposed che-1 mutant at concentrations more than 50 μmol/L. Therefore, impairment of the ASE neuron structures and functions may largely contribute to the appearance of chemotaxis defects to water-soluble attractants in metal exposed nematodes.