Spatial equity in access to urban services is a significant element of sustainable urban planning.To date,a service-based index is used to measure service attractiveness,considering attractiveness as a static concept....Spatial equity in access to urban services is a significant element of sustainable urban planning.To date,a service-based index is used to measure service attractiveness,considering attractiveness as a static concept.While from the user side view,service attractiveness is a dynamic concept related to the variation of different opportunities of users to use the services and capacities.In this paper,a user-based method for measuring service attractiveness is proposed.In this approach,the attractiveness of service for a user is modeled as a function of the user's Travel Times(TT),Free Times(FTs),park size and relative positions of the user,local demanding population,and service.Then,the inequity of attractiveness of services for different users has been examined using three inequity indices including the Duration of Use(DU),Frequency of Visit(FV),and the Chance of Space Choice(CSC).The proposed method is applied to urban regional parks of Tehran municipality.Traffc Analysis Zones(TAZs)and regional parks are respectively regarded as the users and services.In addition to considering inequity of access to the first closest park,the additional cost of accessing to the other two closest parks is also considered.Results show that the proposed method leads to the exploration of the existing inequities of DU,FV,and CSC among residents in local scales,whereas in the service-based method,all users of a service are highlighted with a single value of attractiveness.Comparison of the user-based and service-based attractiveness indices show significant differences.As an example,user-based attractiveness values of about 14%and 20%of TAZs are respectively 5 and 3 square meters more than that of the service-based attractiveness index.However,the service-based method is suitable for regional-scale comparison of the inequities.Therefore,the proposed index can complement the service-based index for inequity mapping and management in varying scales.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
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
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
This paper discusses the definition and connotation of Theme Shopping Tourism(TST) destination,and reveals the attractive distance of TST destination based on the utility function derived from the supposed demand func...This paper discusses the definition and connotation of Theme Shopping Tourism(TST) destination,and reveals the attractive distance of TST destination based on the utility function derived from the supposed demand function.An attractive model is deduced.According to this attractive model,it is can be known that the attractive distance is related to the price difference of the theme commodities between TST destination and tourist origin place,the average expenditure of transport,the demand elasticity of price,the actual price of sightseeing spot,the critical price that a tourist will afford,the number of nights that a tourist stays on the TST destination and the price level of accommodation in the TST destination.The change mechanism of attractive distance of TST destinations is revealed in this paper,and implications on TST marketing are put forward.First,theme commodities should be luxuries.Second,lower price is the primary pulling factor of theme shopping tourism.Third,the route combining with sightseeing spots is beneficial to shopping tourism.At last,TST development is one way of rejuvenating the falling destinations.展开更多
Animation creates a vivid, virtual world and expands the scope of human imagination. In this study, we investigated the time-courses of brain responses related to the evaluation of the attractiveness of cartoon faces ...Animation creates a vivid, virtual world and expands the scope of human imagination. In this study, we investigated the time-courses of brain responses related to the evaluation of the attractiveness of cartoon faces using the event-related potential （ERP） technique. The results demonstrated that N170 amplitude was higher for attractive than for unattractive cartoon faces in males, while the opposite was found in females. Facial attractiveness notably modulated the late positive component （LPC）, which might reflect the task-related process of aesthetic appraisal of beauty. The mean LPC amplitude in males was significantly higher for attractive cartoon faces than for unattractive faces, while the LPC amplitude in females did not significantly differ between attractive and unattractive cartoon faces. Moreover, the paint mode （computer graphics, gouache, and stick figure） modulated the early encoding of facial structures and the late evaluative process. The early modulation effect by paint mode may be related to the spatial frequency of the pictures. The processing speed and intensity in females were both higher than those in males. In conclusion, our study, for the first time, reported ERP modulation based on the assessment of cartoon facial attractiveness, suggesting the facilitated selection of attractiveness information at the early stage, and that the attentional enhancement of attractive faces at the late stage only exists in males. This suggests that men＇s brains are hard-wired to be sensitive to facial beauty, even in cartoons.展开更多
In this paper,we solve the Dirac equation under spin symmetry limit for attractive radial potential including a Coulomb-like tensor interaction.By using the parametric generalization of the Nikiforov-Uvarov method,the...In this paper,we solve the Dirac equation under spin symmetry limit for attractive radial potential including a Coulomb-like tensor interaction.By using the parametric generalization of the Nikiforov-Uvarov method,the energy eigenvalues equation and the corresponding wave functions have been obtained in closed forms.Some numerical results are given too.展开更多
Contemporary villages of the mountain region are subject to uncontrolled structural and spatial transformations,which cause deformation of centuries-old spatial systems of high cultural and natural value.The aim of th...Contemporary villages of the mountain region are subject to uncontrolled structural and spatial transformations,which cause deformation of centuries-old spatial systems of high cultural and natural value.The aim of the study is to confront the opinions of the inhabitants and experts regarding the condition of the cultural landscape of the villages in south-eastern Poland.This area belongs to the Carpathian region of Central Europe.The historical and economic conditions of the studied region,related to the functioning in the post-war period,and then its breakdown and the development of the free market economy,constitute an interesting background for the proposed research.Local communities still remembering the period of difficulties related to the period of systemic transformations,are currently experiencing a relative prosperity,many difficulties related to the period of systemic transformations,are currently experiencing a relative prosperity,which is also expressed in a completely new,previously unknown way of managing the landscape.Investments implemented in villages are associated by the inhabitants with the improvement of the standards and quality of life.They assess them rather positively.An expert assessment of these landscape transformations indicates their negative dimension and the risk of losing timeless values.The discrepancy in the assessment of experts and local residents creates difficulties in the protection of the rural landscape.Therefore,high-quality visual landscape features among rural residents is necessary from the point of view of its multi-faceted and effective protection.Local initiatives and actions in the field of industry policy should play a significant role in this respect by consolidating the images of a harmonious landscape in the public awareness.展开更多
By constructing two suitable generalized Lyapunov functions,we derived a generalized ellipsoidal estimate of the globally attractive set and positively invariant set of the unified chaotic system with the parameters ...By constructing two suitable generalized Lyapunov functions,we derived a generalized ellipsoidal estimate of the globally attractive set and positively invariant set of the unified chaotic system with the parameters α=1/29 and 1/29<α<2/29,respectively,which extends some related results of Li,et al. [Li DM,Lu JA,Wu XQ,Chen GR,Estimating the global basin of attraction and positively invariant set for the Lorenz system and a unified chaotic system,Journal of Mathematical Analysis and Applications,2006,323(2): 844-853]. The theoretical results obtained in this paper will find wide application in chaos control and synchronization.展开更多
Alzheimer’s disease(AD)is a progressive neurodegenerative condition that goes f rom mild cogni t ive impai rment in prodromal disease to severely disabling deficits in advanced stages.The risk for AD development,as w...Alzheimer’s disease(AD)is a progressive neurodegenerative condition that goes f rom mild cogni t ive impai rment in prodromal disease to severely disabling deficits in advanced stages.The risk for AD development,as well as progression and severity,clearly differ between men and women(Pike,2017).Epidemiological studies have shown that there is a significantly increased prevalence in the development of AD in women compared to men,which is usually explained by the longer lifespan of women.This increased frequency may be due to the interplay between age and sex,in which genetic factors together with hormonal and metabolic patterns play a crucial role.Moreover,cognitive impairment has been confirmed to be greater in women than in men at the same stage of AD,likely due to reduced estrogen levels in postmenopausal women(Laws et al.,2016).展开更多
Men and women at Northwest University （n=751）, Xi＇an, China were asked to judge the attractiveness of photographs of female patients who had undergone micrograft surgery to reduce their waist-to-hip ratios （WHR）....Men and women at Northwest University （n=751）, Xi＇an, China were asked to judge the attractiveness of photographs of female patients who had undergone micrograft surgery to reduce their waist-to-hip ratios （WHR）. Micrograft surgery involves harvesting adipose tissue from the waist and reshaping the buttocks to produce a low WHR and an ‘hourglass＇ female figure. This gynoid distribution of female body fat has been shown to correlate with measures of fertility and health. Significantly larger numbers of subjects, of both sexes, chose post-operative photographs, with lower WHRs, as more attractive than pre-operative photographs of the same women. Some patients had gained, and some had lost weight, post-operatively, with resultant changes in body mass index （BMI）. However, these changes in BMI were not related to judgments of attractiveness. These results show that the hourglass female figure is rated as attractive in China, and that WHR, rather than BMI, plays a crucial role in such attractiveness judgments.展开更多
In this paper, a new evolving model with tunable attractiveness is presented. Based on the Barabasi-Albert （BA） model, we introduce the attractiveness of node which can change with node degree. Using the mean-field ...In this paper, a new evolving model with tunable attractiveness is presented. Based on the Barabasi-Albert （BA） model, we introduce the attractiveness of node which can change with node degree. Using the mean-field theory, we obtain the analytical expression of power-law degree distribution with the exponent γ∈ （3, ∞）. The new model is more homogeneous and has a lower clustering coefficient and bigger average path length than the BA model.展开更多
The attractive fixed-point solution of a nonlinear cascade model is stud- ied for the homogeneous isotropic turbulence containing a parameter C, introduced by Desnyansky and Novikov. With a traditional constant positi...The attractive fixed-point solution of a nonlinear cascade model is stud- ied for the homogeneous isotropic turbulence containing a parameter C, introduced by Desnyansky and Novikov. With a traditional constant positive external force added on the first shell equation, it can be found that the attractive fixed-point solution of the model depends on both the parameter C and the external force. Thus, an explicit force is introduced to remove the effects of the external force on the attractive fixed-point solu- tion. F^arthermore, two groups of attractive fixed-point solutions are derived theoretically and studied numerically. One of the groups has the same scaling behavior of the velocity in the whole inertial range and agrees well with those observed by Bell and Nelkin for the nonnegative parameters. The other is found to have different scaling behaviors of the velocity at the odd and even number shells for the negative parameters. This special characteristic may be used to study the anomalous scaling behavior of the turbulence.展开更多
Starting with the many-body SchrSdinger Hamiltonian in R2, we prove that the ground state energy of a two-dimensional interacting Bose gas with the pairwise attractive interaction approaches to the minimum of the Gros...Starting with the many-body SchrSdinger Hamiltonian in R2, we prove that the ground state energy of a two-dimensional interacting Bose gas with the pairwise attractive interaction approaches to the minimum of the Gross-Pitaevskii energy functional in the mean- field regime, as the particle number N → ∞ and however the scattering length → 0. By fixing N｜k｜, this leads to the mean-field approximation of Bose-Einstein condensates with attractive interactions in R^2.展开更多
We approximately solve the Dirac equation for attractive radial potential including a Coulomb-like tensor interaction under pseudospin and the spin symmetry limit for any arbitrary spin-orbit quantum number, by employ...We approximately solve the Dirac equation for attractive radial potential including a Coulomb-like tensor interaction under pseudospin and the spin symmetry limit for any arbitrary spin-orbit quantum number, by employing the supersymmetric （SUSY） quantum mechanics and supersymmetric shape invariance technique. We obtain the energy eigenvalue equation under the pseudospin and spin conditions. Some numerical results are compared with those obtained by the Nikiforove-Uvarov （NU） method.展开更多
Multiple stability for two-dimensional delayed recurrent neural networks with piecewise linear activation flmctions of 2r （r 〉 1） corner points is studied. Sufficient conditions are established for checking the exi...Multiple stability for two-dimensional delayed recurrent neural networks with piecewise linear activation flmctions of 2r （r 〉 1） corner points is studied. Sufficient conditions are established for checking the existence of （2r ＋ 1）2 equilibria in delayed recurrent neural networks. Under these conditions, （r ＋ 1）2 equilibria are locally exponentially stable, and （2r＋ 1）2 -（r ＋ 1）2 -r2 equilibria are unstable. Attractive basins of stable equilibria are estimated, which are larger than invariant sets derived by decomposing state space. One example is provided to illustrate the effectiveness of our results.展开更多
We studied the influences of immune activation by thymus-dependent(sheep red blood cells,SRBC)and independent(bacterial lipopolysaccharide,LPS)antigens on odor signals and endocrine status in dwarf hamsters.Administra...We studied the influences of immune activation by thymus-dependent(sheep red blood cells,SRBC)and independent(bacterial lipopolysaccharide,LPS)antigens on odor signals and endocrine status in dwarf hamsters.Administration of SRBS to mature males resulted in a drop of sexual scent attractiveness of soiled bedding collected during 5 days after injection.This effect was accompanied with a decline of fecal testosterone.Reduction of the male scent attractiveness after SRBC treatment had maximum manifestation in males of dwarf hamsters with low humoral immune response to this challenge.Contrary to the effects of SRBC,males injected with LPS showed an increase of scent attractiveness.Differences in the time that mature females spent sniffing olfactory stimuli(LPS vs control),correlated positively with differences in concentration of testosterone in feces collected from LPS and saline treated males.We discuss the adaptive meaning of the opposite olfactory effects,which induced by activation of the nonspecific innate immunity with LPS and by activation of specific acquired immunity with SRBC.展开更多
Based on the numerical wave function solutions of neutral atoms with attractive interaction in a harmonic trap,we propose an exactly solvable model for macroscopic quantum tunneling of a Bose condensate with attractiv...Based on the numerical wave function solutions of neutral atoms with attractive interaction in a harmonic trap,we propose an exactly solvable model for macroscopic quantum tunneling of a Bose condensate with attractive interaction.We calculate the rate of macroscopic quantum tunneling from a metastable condensate state to the collapse state and analyze the stability of the attractive Bose-Einstein condensation.展开更多
The cytosolic calcium system is inhomogenous because of the discrete and random distribution of ion channels on the ER membrane.It is well known that the spiral tip can be pinned by the heterogenous area,and the field...The cytosolic calcium system is inhomogenous because of the discrete and random distribution of ion channels on the ER membrane.It is well known that the spiral tip can be pinned by the heterogenous area,and the field can detach the spiral from the heterogeneity.We use the adventive field to counteract the attractive force exerting on the calcium spiral wave by the heterogeneity,then the strength of the adventive field is used to quantify the attractive force indirectly.Two factors determining the attractive force are studied.It is found that:(1)the attractive force sharply increases with size of the heterogeneity for small-size heterogeneity,whereas the force increases to a saturated value for large-size heterogeneity;(2)for large-size heterogeneity,the force almost remains constant unless the level of the heterogeneity vanishes,the force decreases to zero linearly and sharply,and for small-size heterogeneity,the force decreases successively with the level of the heterogeneity.Furthermore,it is found that the forces exist only when the spiral tip is very close to the heterogenous area.Our study may shed some light on the control or suppression of the calcium spiral wave.展开更多
External factors influenee the strategic selections, internal strength and management activities of an enterprise. This paper discusses the key factors of industrial attractiveness, puts forward a new method for evalu...External factors influenee the strategic selections, internal strength and management activities of an enterprise. This paper discusses the key factors of industrial attractiveness, puts forward a new method for evaluating industrial attractiveness by using improved Hamming neural net in order to provide scientifie support when an enterprise makes its developing strategies.展开更多
文摘Spatial equity in access to urban services is a significant element of sustainable urban planning.To date,a service-based index is used to measure service attractiveness,considering attractiveness as a static concept.While from the user side view,service attractiveness is a dynamic concept related to the variation of different opportunities of users to use the services and capacities.In this paper,a user-based method for measuring service attractiveness is proposed.In this approach,the attractiveness of service for a user is modeled as a function of the user's Travel Times(TT),Free Times(FTs),park size and relative positions of the user,local demanding population,and service.Then,the inequity of attractiveness of services for different users has been examined using three inequity indices including the Duration of Use(DU),Frequency of Visit(FV),and the Chance of Space Choice(CSC).The proposed method is applied to urban regional parks of Tehran municipality.Traffc Analysis Zones(TAZs)and regional parks are respectively regarded as the users and services.In addition to considering inequity of access to the first closest park,the additional cost of accessing to the other two closest parks is also considered.Results show that the proposed method leads to the exploration of the existing inequities of DU,FV,and CSC among residents in local scales,whereas in the service-based method,all users of a service are highlighted with a single value of attractiveness.Comparison of the user-based and service-based attractiveness indices show significant differences.As an example,user-based attractiveness values of about 14%and 20%of TAZs are respectively 5 and 3 square meters more than that of the service-based attractiveness index.However,the service-based method is suitable for regional-scale comparison of the inequities.Therefore,the proposed index can complement the service-based index for inequity mapping and management in varying scales.
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 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Under the auspices of National Natural Science Foundation of China (No 40571059)
文摘This paper discusses the definition and connotation of Theme Shopping Tourism(TST) destination,and reveals the attractive distance of TST destination based on the utility function derived from the supposed demand function.An attractive model is deduced.According to this attractive model,it is can be known that the attractive distance is related to the price difference of the theme commodities between TST destination and tourist origin place,the average expenditure of transport,the demand elasticity of price,the actual price of sightseeing spot,the critical price that a tourist will afford,the number of nights that a tourist stays on the TST destination and the price level of accommodation in the TST destination.The change mechanism of attractive distance of TST destinations is revealed in this paper,and implications on TST marketing are put forward.First,theme commodities should be luxuries.Second,lower price is the primary pulling factor of theme shopping tourism.Third,the route combining with sightseeing spots is beneficial to shopping tourism.At last,TST development is one way of rejuvenating the falling destinations.
基金supported by the New Talent Program of Zhejiang Province, China (2013R404046)
文摘Animation creates a vivid, virtual world and expands the scope of human imagination. In this study, we investigated the time-courses of brain responses related to the evaluation of the attractiveness of cartoon faces using the event-related potential （ERP） technique. The results demonstrated that N170 amplitude was higher for attractive than for unattractive cartoon faces in males, while the opposite was found in females. Facial attractiveness notably modulated the late positive component （LPC）, which might reflect the task-related process of aesthetic appraisal of beauty. The mean LPC amplitude in males was significantly higher for attractive cartoon faces than for unattractive faces, while the LPC amplitude in females did not significantly differ between attractive and unattractive cartoon faces. Moreover, the paint mode （computer graphics, gouache, and stick figure） modulated the early encoding of facial structures and the late evaluative process. The early modulation effect by paint mode may be related to the spatial frequency of the pictures. The processing speed and intensity in females were both higher than those in males. In conclusion, our study, for the first time, reported ERP modulation based on the assessment of cartoon facial attractiveness, suggesting the facilitated selection of attractiveness information at the early stage, and that the attentional enhancement of attractive faces at the late stage only exists in males. This suggests that men＇s brains are hard-wired to be sensitive to facial beauty, even in cartoons.
文摘In this paper,we solve the Dirac equation under spin symmetry limit for attractive radial potential including a Coulomb-like tensor interaction.By using the parametric generalization of the Nikiforov-Uvarov method,the energy eigenvalues equation and the corresponding wave functions have been obtained in closed forms.Some numerical results are given too.
文摘Contemporary villages of the mountain region are subject to uncontrolled structural and spatial transformations,which cause deformation of centuries-old spatial systems of high cultural and natural value.The aim of the study is to confront the opinions of the inhabitants and experts regarding the condition of the cultural landscape of the villages in south-eastern Poland.This area belongs to the Carpathian region of Central Europe.The historical and economic conditions of the studied region,related to the functioning in the post-war period,and then its breakdown and the development of the free market economy,constitute an interesting background for the proposed research.Local communities still remembering the period of difficulties related to the period of systemic transformations,are currently experiencing a relative prosperity,many difficulties related to the period of systemic transformations,are currently experiencing a relative prosperity,which is also expressed in a completely new,previously unknown way of managing the landscape.Investments implemented in villages are associated by the inhabitants with the improvement of the standards and quality of life.They assess them rather positively.An expert assessment of these landscape transformations indicates their negative dimension and the risk of losing timeless values.The discrepancy in the assessment of experts and local residents creates difficulties in the protection of the rural landscape.Therefore,high-quality visual landscape features among rural residents is necessary from the point of view of its multi-faceted and effective protection.Local initiatives and actions in the field of industry policy should play a significant role in this respect by consolidating the images of a harmonious landscape in the public awareness.
文摘By constructing two suitable generalized Lyapunov functions,we derived a generalized ellipsoidal estimate of the globally attractive set and positively invariant set of the unified chaotic system with the parameters α=1/29 and 1/29<α<2/29,respectively,which extends some related results of Li,et al. [Li DM,Lu JA,Wu XQ,Chen GR,Estimating the global basin of attraction and positively invariant set for the Lorenz system and a unified chaotic system,Journal of Mathematical Analysis and Applications,2006,323(2): 844-853]. The theoretical results obtained in this paper will find wide application in chaos control and synchronization.
文摘Alzheimer’s disease(AD)is a progressive neurodegenerative condition that goes f rom mild cogni t ive impai rment in prodromal disease to severely disabling deficits in advanced stages.The risk for AD development,as well as progression and severity,clearly differ between men and women(Pike,2017).Epidemiological studies have shown that there is a significantly increased prevalence in the development of AD in women compared to men,which is usually explained by the longer lifespan of women.This increased frequency may be due to the interplay between age and sex,in which genetic factors together with hormonal and metabolic patterns play a crucial role.Moreover,cognitive impairment has been confirmed to be greater in women than in men at the same stage of AD,likely due to reduced estrogen levels in postmenopausal women(Laws et al.,2016).
文摘Men and women at Northwest University （n=751）, Xi＇an, China were asked to judge the attractiveness of photographs of female patients who had undergone micrograft surgery to reduce their waist-to-hip ratios （WHR）. Micrograft surgery involves harvesting adipose tissue from the waist and reshaping the buttocks to produce a low WHR and an ‘hourglass＇ female figure. This gynoid distribution of female body fat has been shown to correlate with measures of fertility and health. Significantly larger numbers of subjects, of both sexes, chose post-operative photographs, with lower WHRs, as more attractive than pre-operative photographs of the same women. Some patients had gained, and some had lost weight, post-operatively, with resultant changes in body mass index （BMI）. However, these changes in BMI were not related to judgments of attractiveness. These results show that the hourglass female figure is rated as attractive in China, and that WHR, rather than BMI, plays a crucial role in such attractiveness judgments.
基金supported by the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (Grant No. 2008BAA13B01)
文摘In this paper, a new evolving model with tunable attractiveness is presented. Based on the Barabasi-Albert （BA） model, we introduce the attractiveness of node which can change with node degree. Using the mean-field theory, we obtain the analytical expression of power-law degree distribution with the exponent γ∈ （3, ∞）. The new model is more homogeneous and has a lower clustering coefficient and bigger average path length than the BA model.
基金Project supported by the National Natural Science Foundation of China (No. 10902007)he National Basic Research Program of China (973 Program) (No. 2009CB724001)
文摘The attractive fixed-point solution of a nonlinear cascade model is stud- ied for the homogeneous isotropic turbulence containing a parameter C, introduced by Desnyansky and Novikov. With a traditional constant positive external force added on the first shell equation, it can be found that the attractive fixed-point solution of the model depends on both the parameter C and the external force. Thus, an explicit force is introduced to remove the effects of the external force on the attractive fixed-point solu- tion. F^arthermore, two groups of attractive fixed-point solutions are derived theoretically and studied numerically. One of the groups has the same scaling behavior of the velocity in the whole inertial range and agrees well with those observed by Bell and Nelkin for the nonnegative parameters. The other is found to have different scaling behaviors of the velocity at the odd and even number shells for the negative parameters. This special characteristic may be used to study the anomalous scaling behavior of the turbulence.
基金supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry of China,National Center for Mathematics and Interdisciplinary Sciences in China
文摘Starting with the many-body SchrSdinger Hamiltonian in R2, we prove that the ground state energy of a two-dimensional interacting Bose gas with the pairwise attractive interaction approaches to the minimum of the Gross-Pitaevskii energy functional in the mean- field regime, as the particle number N → ∞ and however the scattering length → 0. By fixing N｜k｜, this leads to the mean-field approximation of Bose-Einstein condensates with attractive interactions in R^2.
文摘We approximately solve the Dirac equation for attractive radial potential including a Coulomb-like tensor interaction under pseudospin and the spin symmetry limit for any arbitrary spin-orbit quantum number, by employing the supersymmetric （SUSY） quantum mechanics and supersymmetric shape invariance technique. We obtain the energy eigenvalue equation under the pseudospin and spin conditions. Some numerical results are compared with those obtained by the Nikiforove-Uvarov （NU） method.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 50977008, 61034005, and 61074073)the National Basic Research Program of China (Grant No. 2009CB320601)+1 种基金the Program for New Century Excellent Talents in Universities of China (Grant No. NCET-10-0306)the Fundamental Research Funds for the Central Universities of China(Grant Nos. N110604005 and N110504001)
文摘Multiple stability for two-dimensional delayed recurrent neural networks with piecewise linear activation flmctions of 2r （r 〉 1） corner points is studied. Sufficient conditions are established for checking the existence of （2r ＋ 1）2 equilibria in delayed recurrent neural networks. Under these conditions, （r ＋ 1）2 equilibria are locally exponentially stable, and （2r＋ 1）2 -（r ＋ 1）2 -r2 equilibria are unstable. Attractive basins of stable equilibria are estimated, which are larger than invariant sets derived by decomposing state space. One example is provided to illustrate the effectiveness of our results.
文摘We studied the influences of immune activation by thymus-dependent(sheep red blood cells,SRBC)and independent(bacterial lipopolysaccharide,LPS)antigens on odor signals and endocrine status in dwarf hamsters.Administration of SRBS to mature males resulted in a drop of sexual scent attractiveness of soiled bedding collected during 5 days after injection.This effect was accompanied with a decline of fecal testosterone.Reduction of the male scent attractiveness after SRBC treatment had maximum manifestation in males of dwarf hamsters with low humoral immune response to this challenge.Contrary to the effects of SRBC,males injected with LPS showed an increase of scent attractiveness.Differences in the time that mature females spent sniffing olfactory stimuli(LPS vs control),correlated positively with differences in concentration of testosterone in feces collected from LPS and saline treated males.We discuss the adaptive meaning of the opposite olfactory effects,which induced by activation of the nonspecific innate immunity with LPS and by activation of specific acquired immunity with SRBC.
基金Supported by the National Natural Science Foundation of China under Grant No.69778011.
文摘Based on the numerical wave function solutions of neutral atoms with attractive interaction in a harmonic trap,we propose an exactly solvable model for macroscopic quantum tunneling of a Bose condensate with attractive interaction.We calculate the rate of macroscopic quantum tunneling from a metastable condensate state to the collapse state and analyze the stability of the attractive Bose-Einstein condensation.
基金Supported by the Fundamental Research Funds for the Central Universities of China under Grant No 2010QNA36the National Natural Science Foundation of China under Grant Nos 11105219(JT)and 11265008(JM).
文摘The cytosolic calcium system is inhomogenous because of the discrete and random distribution of ion channels on the ER membrane.It is well known that the spiral tip can be pinned by the heterogenous area,and the field can detach the spiral from the heterogeneity.We use the adventive field to counteract the attractive force exerting on the calcium spiral wave by the heterogeneity,then the strength of the adventive field is used to quantify the attractive force indirectly.Two factors determining the attractive force are studied.It is found that:(1)the attractive force sharply increases with size of the heterogeneity for small-size heterogeneity,whereas the force increases to a saturated value for large-size heterogeneity;(2)for large-size heterogeneity,the force almost remains constant unless the level of the heterogeneity vanishes,the force decreases to zero linearly and sharply,and for small-size heterogeneity,the force decreases successively with the level of the heterogeneity.Furthermore,it is found that the forces exist only when the spiral tip is very close to the heterogenous area.Our study may shed some light on the control or suppression of the calcium spiral wave.
基金The research work of this paper is hunded by National Natural Science Foundation of China.No.7957004
文摘External factors influenee the strategic selections, internal strength and management activities of an enterprise. This paper discusses the key factors of industrial attractiveness, puts forward a new method for evaluating industrial attractiveness by using improved Hamming neural net in order to provide scientifie support when an enterprise makes its developing strategies.
