The dynamics of the moving-with-constant-velocity internal pressure acting on the inner surface of the hollow circular cylinder surrounded by an infinite elastic medium is studied within the scope of the piecewise hom...The dynamics of the moving-with-constant-velocity internal pressure acting on the inner surface of the hollow circular cylinder surrounded by an infinite elastic medium is studied within the scope of the piecewise homogeneous body model by employing the exact field equations of the linear theory of elastodynamics.It is assumed that the internal pressure is point-located with respect to the cylinder axis and is axisymmetric in the circumferential direction.Moreover,it is assumed that shear-spring type imperfect contact conditions on the interface between the cylinder and surrounding elastic medium are satisfied.The focus is on the influence of the mentioned imperfectness on the critical velocity of the moving load and this is the main contribution and difference of the present paper the related other ones.The other difference of the present work from the related other ones is the study of the response of the interface stresses to the load moving velocity,distribution of these stresses with respect to the axial coordinates and to the time.At the same time,the present work contains detail analyses of the influence of problem parameters such as the ratio of modulus of elasticity,the ratio of the cylinder thickness to the cylinder radius,and the shear-spring type parameter which characterizes the degree of the contact imperfection on the values of the critical velocity and stress distribution.Corresponding numerical results are presented and discussed.In particular,it is established that the values of the critical velocity of the moving pressure decrease with the external radius of the cylinder under constant thickness of that.展开更多
With deep research into historical gardens as well as the existing ones in both China and Japan, this article compares the gardens' origins and evolution in the two countries, and draws the conclusion that the gar...With deep research into historical gardens as well as the existing ones in both China and Japan, this article compares the gardens' origins and evolution in the two countries, and draws the conclusion that the gardens in each country emerged and developed naturally, and classical Chinese gardens originated earlier than those in Japan, but made their progress in a much slower way.展开更多
Nucleation mechanism and technological process for Ni-Fe co-deposition with a relatively high Fe^(2+)concentration surrounded were described,and the effects of Fe^(2+) concentration,solution pH,temperature,and sodium ...Nucleation mechanism and technological process for Ni-Fe co-deposition with a relatively high Fe^(2+)concentration surrounded were described,and the effects of Fe^(2+) concentration,solution pH,temperature,and sodium dodecyl sulfonate concentration were investigated.Electrochemical experiments demonstrate that iron's electrodeposition plays a leading role in the Ni-Fe co-deposition process,and the co-deposition nucleation mechanism accords with a progressive nucleation.Temperature increase does favor in increasing nickel content in the ferronickel(Ni-Fe co-deposition products),while Fe^(2+) concentration increase does not.When solution pH is higher than 3.5,nickel content in the ferronickel decreases with pH because of the hydrolysis of Fe^(2+).With the current density of 180 A/m^2,Na_2SO_4 concentration of 100 g/L and Ni^(2+) concentration of 60 g/L,a smooth ferronickel deposit containing 96.21% Ni can be obtained under the conditions of temperature of 60 °C,Fe^(2+) concentration of 0.3 g/L,solution pH of 3 and sodium dodecyl sulfonate concentration of 40 mg/L.展开更多
There are several misunderstandings about“family”in today’s world:first,“individual”and“family”are viewed as two incompatible choices of values;second,the existential experience of“affection towards their rela...There are several misunderstandings about“family”in today’s world:first,“individual”and“family”are viewed as two incompatible choices of values;second,the existential experience of“affection towards their relatives(qin qin)”is confused with the institutional expression of“family”in history;third,the asymmetric structure of“family”is wrongly taken as the root of a relationship between superiority and subordination;fourth,there is a false assumption that one’s role and responsibility within the family is incompatible with freedom as an individual in the modern world;fifth,“family”is merely viewed as a social organization,and its identity as a spiritual and cultural existence is largely neglected.In that sense,the inherent value of“family”is overlooked in the modern world.Reestablishing an idea of“family”surrounded by“individual consciousness”in the modern context can clarify the positive value of“family”,make“family”a solid guarantee for the achievements of“individuals”,and effectively relieve the negative consequences of the“individual standard”.Meanwhile,the modern world must also renew the relationship between“cultivating the moral self and regulating the family”and“running the state rightly and making the world peaceful”,and help“family”exert a more universal influence.“Family”must be reinterpreted as a basic pattern of human existence and the modern world must redefine the ontological meaning of“family”as a carrier of“relationships”,an“emotional encounter”,an“ethical principle”,a“way of understanding the world”and a“method to transcend spiritually”.展开更多
Makonde woodcarving gains an audience in China through couple Li Songshan and Han Rong THE Makonde are an ethnic group living along the Tanzania-Mozambique border.They are considered some of Africa’s most talented wo...Makonde woodcarving gains an audience in China through couple Li Songshan and Han Rong THE Makonde are an ethnic group living along the Tanzania-Mozambique border.They are considered some of Africa’s most talented woodcarvers and their craftsmanship has been passed down from generation to generation.Makonde woodcarving is often referred to as the grandfather of modern African wood sculpture.Its exaggerated human and animal patterns reflect the essence of traditional African culture,full of imagination and inspired by nature.展开更多
I know it is wrong to envy your children.But when I see my son,Tonio and his younger brother Sam going down a slide together,one’s arm around the other,I know I have missed something wonderful.Not only did I never ha...I know it is wrong to envy your children.But when I see my son,Tonio and his younger brother Sam going down a slide together,one’s arm around the other,I know I have missed something wonderful.Not only did I never have a brother,but also I had no friendships like theirs.My sister was old enough to help take care of me,so she was more a mother than a playmate,and I was more a pest than a friend.A brother would have been wonderful,but it was not in the family planning.展开更多
The quasinormal modes of the Schwarzschild black hole surrounded by the quintessence in Rastall gravity are studied using the sixth-order Wentzel-Kramers-Brillouin approximative approach. The effect of the Rastall par...The quasinormal modes of the Schwarzschild black hole surrounded by the quintessence in Rastall gravity are studied using the sixth-order Wentzel-Kramers-Brillouin approximative approach. The effect of the Rastall parameter on the quasinormal modes of gravitational, electromagnetic and massless scalar perturbations is explored. Compared to the case of Einstein gravity, it is found that, when η < 0, the gravitational field, electromagnetic field as well as massless scalar field damp more rapidly and have larger real frequency of oscillation in Rastall gravity, while when η > 0, the gravitational field, electromagnetic field as well as massless scalar field damp more slowly and have smaller real frequency of oscillation in Rastall gravity. It is also found that the gravitational field, electromagnetic field as well as massless scalar field damp more and more slowly and the real frequency of oscillation for the gravitational perturbation, electromagnetic perturbation as well as massless scalar perturbation becomes smaller and smaller as the Rastall parameter η increases.Compared among the quasinormal frequencies of gravitational, electromagnetic and massless scalar perturbations, I find that, for fixed η,(l, n), ε and Nq, the oscillation damps most slowly for the gravitational perturbation, mediate for the electromagnetic perturbation and most rapidly for the massless scalar perturbation, and the real frequency of oscillation is the smallest for the gravitational perturbation, mediate for the electromagnetic perturbation and the largest for the massless scalar perturbation in Rastall gravity.展开更多
The energy content of the charged-Kerr(CK)spacetime surrounded by dark energy(DE)is investigated using approximate Lie symmetry methods for the differential equations.For this,we consider three different DE scenarios:...The energy content of the charged-Kerr(CK)spacetime surrounded by dark energy(DE)is investigated using approximate Lie symmetry methods for the differential equations.For this,we consider three different DE scenarios:cosmological constant with an equation of state parameter$ω_(q)=-2/3,quintessence DE with an equation of state parameterω_(c)=-1,and a frustrated network of cosmic strings with an equation of state parameterω_(n)=-1/3.To study the gravitational energy of the CK black hole surrounded by the DE,we explore the symmetries of the 2nd-order perturbed geodesic equations.It is noticed,for all the values ofω,the exact symmetries are recovered as 2nd-order approximate trivial symmetries.These trivial approximate symmetries give the rescaling of arc length parameter s in this spacetime which indicates that the energy in the underlying spacetime has to be rescaled by a factor that depends on the black hole parameters and the DE parameter.This rescaling factor is compared with the factor of the CK spacetime found in[Hussain et al.Gen.Relativ.Gravit.(2009)]and the effects of the DE on it are discussed.It is observed that for all the three values of the equation of state parameterω,the effect of DE results in decreased energy content of the black hole spacetime,regardless of values of the charge Q,spin a and the DE parameterα.This reduction in the energy content due to the involvement of the DE favours the idea of mass reduction of black holes by accretion of DE given by[Babichev et al.Phys.Rev.Lett.(2004)].展开更多
文摘The dynamics of the moving-with-constant-velocity internal pressure acting on the inner surface of the hollow circular cylinder surrounded by an infinite elastic medium is studied within the scope of the piecewise homogeneous body model by employing the exact field equations of the linear theory of elastodynamics.It is assumed that the internal pressure is point-located with respect to the cylinder axis and is axisymmetric in the circumferential direction.Moreover,it is assumed that shear-spring type imperfect contact conditions on the interface between the cylinder and surrounding elastic medium are satisfied.The focus is on the influence of the mentioned imperfectness on the critical velocity of the moving load and this is the main contribution and difference of the present paper the related other ones.The other difference of the present work from the related other ones is the study of the response of the interface stresses to the load moving velocity,distribution of these stresses with respect to the axial coordinates and to the time.At the same time,the present work contains detail analyses of the influence of problem parameters such as the ratio of modulus of elasticity,the ratio of the cylinder thickness to the cylinder radius,and the shear-spring type parameter which characterizes the degree of the contact imperfection on the values of the critical velocity and stress distribution.Corresponding numerical results are presented and discussed.In particular,it is established that the values of the critical velocity of the moving pressure decrease with the external radius of the cylinder under constant thickness of that.
文摘With deep research into historical gardens as well as the existing ones in both China and Japan, this article compares the gardens' origins and evolution in the two countries, and draws the conclusion that the gardens in each country emerged and developed naturally, and classical Chinese gardens originated earlier than those in Japan, but made their progress in a much slower way.
基金Project(51574135)supported by the National Natural Science Foundation of ChinaProject(KKPT201563022)supported by Collaborative Innovation Center of Kunming University of Science and Technology,China
文摘Nucleation mechanism and technological process for Ni-Fe co-deposition with a relatively high Fe^(2+)concentration surrounded were described,and the effects of Fe^(2+) concentration,solution pH,temperature,and sodium dodecyl sulfonate concentration were investigated.Electrochemical experiments demonstrate that iron's electrodeposition plays a leading role in the Ni-Fe co-deposition process,and the co-deposition nucleation mechanism accords with a progressive nucleation.Temperature increase does favor in increasing nickel content in the ferronickel(Ni-Fe co-deposition products),while Fe^(2+) concentration increase does not.When solution pH is higher than 3.5,nickel content in the ferronickel decreases with pH because of the hydrolysis of Fe^(2+).With the current density of 180 A/m^2,Na_2SO_4 concentration of 100 g/L and Ni^(2+) concentration of 60 g/L,a smooth ferronickel deposit containing 96.21% Ni can be obtained under the conditions of temperature of 60 °C,Fe^(2+) concentration of 0.3 g/L,solution pH of 3 and sodium dodecyl sulfonate concentration of 40 mg/L.
文摘There are several misunderstandings about“family”in today’s world:first,“individual”and“family”are viewed as two incompatible choices of values;second,the existential experience of“affection towards their relatives(qin qin)”is confused with the institutional expression of“family”in history;third,the asymmetric structure of“family”is wrongly taken as the root of a relationship between superiority and subordination;fourth,there is a false assumption that one’s role and responsibility within the family is incompatible with freedom as an individual in the modern world;fifth,“family”is merely viewed as a social organization,and its identity as a spiritual and cultural existence is largely neglected.In that sense,the inherent value of“family”is overlooked in the modern world.Reestablishing an idea of“family”surrounded by“individual consciousness”in the modern context can clarify the positive value of“family”,make“family”a solid guarantee for the achievements of“individuals”,and effectively relieve the negative consequences of the“individual standard”.Meanwhile,the modern world must also renew the relationship between“cultivating the moral self and regulating the family”and“running the state rightly and making the world peaceful”,and help“family”exert a more universal influence.“Family”must be reinterpreted as a basic pattern of human existence and the modern world must redefine the ontological meaning of“family”as a carrier of“relationships”,an“emotional encounter”,an“ethical principle”,a“way of understanding the world”and a“method to transcend spiritually”.
文摘Makonde woodcarving gains an audience in China through couple Li Songshan and Han Rong THE Makonde are an ethnic group living along the Tanzania-Mozambique border.They are considered some of Africa’s most talented woodcarvers and their craftsmanship has been passed down from generation to generation.Makonde woodcarving is often referred to as the grandfather of modern African wood sculpture.Its exaggerated human and animal patterns reflect the essence of traditional African culture,full of imagination and inspired by nature.
文摘I know it is wrong to envy your children.But when I see my son,Tonio and his younger brother Sam going down a slide together,one’s arm around the other,I know I have missed something wonderful.Not only did I never have a brother,but also I had no friendships like theirs.My sister was old enough to help take care of me,so she was more a mother than a playmate,and I was more a pest than a friend.A brother would have been wonderful,but it was not in the family planning.
基金Supported by the National Nature Science Foundation of Education Department of Shannxi Province under Grant No.15JK1077the Doctorial Scientific Research Starting Fund of Shannxi University of Science and Technology under Grant No.BJ12-02
文摘The quasinormal modes of the Schwarzschild black hole surrounded by the quintessence in Rastall gravity are studied using the sixth-order Wentzel-Kramers-Brillouin approximative approach. The effect of the Rastall parameter on the quasinormal modes of gravitational, electromagnetic and massless scalar perturbations is explored. Compared to the case of Einstein gravity, it is found that, when η < 0, the gravitational field, electromagnetic field as well as massless scalar field damp more rapidly and have larger real frequency of oscillation in Rastall gravity, while when η > 0, the gravitational field, electromagnetic field as well as massless scalar field damp more slowly and have smaller real frequency of oscillation in Rastall gravity. It is also found that the gravitational field, electromagnetic field as well as massless scalar field damp more and more slowly and the real frequency of oscillation for the gravitational perturbation, electromagnetic perturbation as well as massless scalar perturbation becomes smaller and smaller as the Rastall parameter η increases.Compared among the quasinormal frequencies of gravitational, electromagnetic and massless scalar perturbations, I find that, for fixed η,(l, n), ε and Nq, the oscillation damps most slowly for the gravitational perturbation, mediate for the electromagnetic perturbation and most rapidly for the massless scalar perturbation, and the real frequency of oscillation is the smallest for the gravitational perturbation, mediate for the electromagnetic perturbation and the largest for the massless scalar perturbation in Rastall gravity.
文摘The energy content of the charged-Kerr(CK)spacetime surrounded by dark energy(DE)is investigated using approximate Lie symmetry methods for the differential equations.For this,we consider three different DE scenarios:cosmological constant with an equation of state parameter$ω_(q)=-2/3,quintessence DE with an equation of state parameterω_(c)=-1,and a frustrated network of cosmic strings with an equation of state parameterω_(n)=-1/3.To study the gravitational energy of the CK black hole surrounded by the DE,we explore the symmetries of the 2nd-order perturbed geodesic equations.It is noticed,for all the values ofω,the exact symmetries are recovered as 2nd-order approximate trivial symmetries.These trivial approximate symmetries give the rescaling of arc length parameter s in this spacetime which indicates that the energy in the underlying spacetime has to be rescaled by a factor that depends on the black hole parameters and the DE parameter.This rescaling factor is compared with the factor of the CK spacetime found in[Hussain et al.Gen.Relativ.Gravit.(2009)]and the effects of the DE on it are discussed.It is observed that for all the three values of the equation of state parameterω,the effect of DE results in decreased energy content of the black hole spacetime,regardless of values of the charge Q,spin a and the DE parameterα.This reduction in the energy content due to the involvement of the DE favours the idea of mass reduction of black holes by accretion of DE given by[Babichev et al.Phys.Rev.Lett.(2004)].