In this paper the conformal invariance by infinitesimal transformations of first-order Lagrange systems is discussed in detail. The necessary and sumeient conditions of conformal invariance by the action of infinitesi...In this paper the conformal invariance by infinitesimal transformations of first-order Lagrange systems is discussed in detail. The necessary and sumeient conditions of conformal invariance by the action of infinitesimal transformations being Lie symmetry simultaneously are given. Then we get the conserved quantities of conformal invariance by the infinitesimal transformations. Finally an example is given to illustrate the application of the results.展开更多
Applying Parikh＇s quantum tunneling model, we study the quantum tunneling radiation of Reissne- Nordstrom de Sitter black hole with a global monopole. The result shows that the tunneling rates at the event horizon an...Applying Parikh＇s quantum tunneling model, we study the quantum tunneling radiation of Reissne- Nordstrom de Sitter black hole with a global monopole. The result shows that the tunneling rates at the event horizon and the cosmic horizon are related to Bekenstein-Hawking entropy if we take the energy conservation into consideration, and the true radiate spectrum is not precisely thermal.展开更多
The paper studies the form invariance and a type of non-Noether conserved quantity called Mei conserved quantity for non-holonomic systems with variable mass and unilateral constraints. Acoording to the invariance of ...The paper studies the form invariance and a type of non-Noether conserved quantity called Mei conserved quantity for non-holonomic systems with variable mass and unilateral constraints. Acoording to the invariance of the form of differential equations of motion under infinitesimal transformations, this paper gives the definition and criterion of the form invariance for non-holonomic systems with variable mass and unilateral constraints. The condition under which a form invariance can lead to Mei conservation quantity and the form of the conservation quantity are deduced. An example is given to illustrate the application of the results.展开更多
This paper focuses on studying a conformal invariance and a Noether symmetry, a Lie symmetry for a Birkhoffian system in event space. The definitions of the conformal invariance of the system are given. By investigati...This paper focuses on studying a conformal invariance and a Noether symmetry, a Lie symmetry for a Birkhoffian system in event space. The definitions of the conformal invariance of the system are given. By investigation on the relations between the conformal invariance and the Noether symmetry, the conformal invariance and the Lie symmetry, the expressions of conformal factors of the system under these circumstances are obtained. The Noether conserved quantities and the Hojman conserved quantities directly derived from the conformal invariance are given. Two examples are given to illustrate the application of the results.展开更多
The current study explores how the ideological struggle is unfolded in the movie Forrest Gump （1994）. Through a critical examination of the text structure of the plot and the language used by four main characters, i...The current study explores how the ideological struggle is unfolded in the movie Forrest Gump （1994）. Through a critical examination of the text structure of the plot and the language used by four main characters, it demonstrates that conservatism has gained great victory over liberalism in the following way： Those with conservative values are highlighted repeatedly in a favorable way, while those who preach liberal values are frequently associated with tragic events, and ultimately, the latter all converted into conservatives in one way or another, which indicates a reconciliation between the two opposing ideologies. This study might shed light on how visual media can be geared towards political justifications, and bring audience to the level of conscious awareness of that effect展开更多
AIM:To investigate the clinicopathologic features of bile duct tumor thrombus(BDTT) occurrence after treatment of primary small hepatocellular carcinoma(sHCC) .METHODS:A total of 423 patients with primary sHCC admitte...AIM:To investigate the clinicopathologic features of bile duct tumor thrombus(BDTT) occurrence after treatment of primary small hepatocellular carcinoma(sHCC) .METHODS:A total of 423 patients with primary sHCC admitted to our hospital underwent surgical resection or local ablation.During follow-up,only six patients were hospitalized due to obstructive jaundice,which occurred 5-76 mo after initial treatment.The clinicopathologic features of these six patients were reviewed.RESULTS:Six patients underwent hepatic resection(n=5) or radio-frequency ablation(n=1) due to primary sHCC.Five cases had an R1 resection margin,and one case had an ablative margin less than 5.0 mm.No vascular infiltration,microsatellites or bile duct/canaliculus affection was noted in the initial resected specimens.During the follow-up,imaging studies revealed a macroscopic BDTT extending to the common bile duct in all six patients.Four patients had a concomitant intrahepatic recurrent tumor.Surgical re-resection of intrahepatic recurrent tumors and removal of BDTTs(n=4) ,BDTT removal through choledochotomy(n= 1) ,and conservative treatment(n=1) was performed.Microscopic portal vein invasion was noted in three of the four resected specimens.All six patients died,with a mean survival of 11 mo after BDTT removal or conservative treatment.CONCLUSION:BDTT occurrence is a rare,special recurrent pattern of primary sHCC.Patients with BDTTs extending to the common bile duct usually have an unfavorable prognosis even following aggressive surgery.Insufficient resection or ablative margins against primary sHCC may be a risk factor for BDTT development.展开更多
Conformal invariance and a new type of conserved quantities of mechanical systems with variable mass in phase space are studied. Firstly, the definition and determining equation of conformal invariance are presented. ...Conformal invariance and a new type of conserved quantities of mechanical systems with variable mass in phase space are studied. Firstly, the definition and determining equation of conformal invariance are presented. The relationship between the conformal invariance and the Lie symmetry is given, and the necessary and sufficient condition that the conformal invarianee would be the Lie symmetry under the infinitesimal transformations is provided. Secondly, a new type of conserved quantities of the conformal invariance are obtained by using the Lie symmetry of the system. Lastly, an example is given to illustrate the application of the results.展开更多
Experiment investigations on crack propagation of silver based contact surface are carried out with various currents and contact closed forces.It is found that crack propagation of contact surface is caused by arc ene...Experiment investigations on crack propagation of silver based contact surface are carried out with various currents and contact closed forces.It is found that crack propagation of contact surface is caused by arc energy and contact closed forces.Meanwhile, the energy equilibrium equation of crack propagation of silver based contact material under arc energy and contact closed force is provided.展开更多
A mass-conservative average flow model based on the finite element method(FEM) is introduced to predict the performances of textured surfaces applied in mechanical seals or thrust bearings.In this model,the Jakobsson-...A mass-conservative average flow model based on the finite element method(FEM) is introduced to predict the performances of textured surfaces applied in mechanical seals or thrust bearings.In this model,the Jakobsson-Floberg-Olsson(JFO) boundary conditions are applied to the average flow model for ensuring the mass-conservative law.Moreover,the non-uniform triangular grid is utilized,which can deal with the problem of complex geometric shapes.By adopting the modeling techniques,the model proposed here is capable of dealing with complex textured surfaces.The algorithm is proved correct by the numerical experiment.In addition,the model is employed to gain further insight into the influences of the dimples with different shapes and orientations on smooth and rough surfaces on the load-carrying capacity.展开更多
Based on Wu＇s elimination method and ＂divide-and-conquer＂ strategy, the undetermined coefficient algorithm to construct polynomial form conservation laws for nonlinear differential-difference equations （DDEs） is ...Based on Wu＇s elimination method and ＂divide-and-conquer＂ strategy, the undetermined coefficient algorithm to construct polynomial form conservation laws for nonlinear differential-difference equations （DDEs） is improved. Furthermore, a Maple package named CLawDDEs, which can entirely automatically derive polynomial form conservation laws of nonlinear DDEs is presented. The effective- ness of CLawDDEs is demonstrated by application to different kinds of examples.展开更多
Inspired by Verlinde’s idea,some modified versions of entropic gravity have been suggested.Extending them in a unified formalism,herein we derive the generalized gravitational equations accordingly.From gravitational...Inspired by Verlinde’s idea,some modified versions of entropic gravity have been suggested.Extending them in a unified formalism,herein we derive the generalized gravitational equations accordingly.From gravitational equations,the energy-momentum conservation law and cosmological equations are investigated.The covariant conservation law of energy-momentum tensor severely constrains viable modifications of entropic gravity.A discrepancy arises when two independent methods are applied to the homogeneous isotropic universe,posing a serious challenge to modified models of entropic gravity.展开更多
Although the degree of mate competition, given extreme differences in sex ratio, explains much of the pattern of male-biased size dimorphism among diverse taxa, it fails for some species which have potential for inten...Although the degree of mate competition, given extreme differences in sex ratio, explains much of the pattern of male-biased size dimorphism among diverse taxa, it fails for some species which have potential for intense male competition for mates and yet exhibit little or no sexual size dimorphism （SSD）. This fact suggest that species with low SSD should be express the effect of evolutionary pressure in non-obvious geometrical shape promoted by sex ratio in an evolutionary time scale. To evaluate this hypothesis we used phylogenetic comparative method in a Bayesian framework to investigate the evolution of SSD and the role of sex ratio at inter-specific level in the species of Ceroglossus （Coleoptera： Carabidae）. In our results the proportion farthest from 1：1 is associated with more disparate body shape, even though the entire group has minimum variation in sex ratio, which is an intrinsic life history character of this group considering its phylogenetic conservatism or phylogenetic signal. We suggest that the sex ratio has determined the dimorphism degree during evolution of this group, since both traits have increased or decreased together during the species divergence （i.e. positive phylogenetic correlation： r2=0.85）. We suggest that morphological studies of SSD will benefit from using comparative method with Bayesian approaches to assess the effect of phylogenetic history and its uncertainty. Finally, this will be allow to researchers to quantify the uncertainty of specific evolutionary hypotheses accounting for observed sexual dimorphism patterns.展开更多
基金supported by National Natural Science Foundation of China under Grant Nos.10472040,10572021,and 10772025the Outstanding Young Talents Training Fund of Liaoning Province of China under Grant No.3040005
文摘In this paper the conformal invariance by infinitesimal transformations of first-order Lagrange systems is discussed in detail. The necessary and sumeient conditions of conformal invariance by the action of infinitesimal transformations being Lie symmetry simultaneously are given. Then we get the conserved quantities of conformal invariance by the infinitesimal transformations. Finally an example is given to illustrate the application of the results.
基金The project supported by National Natural Science Foundation of China under Grant No. 10347008
文摘Applying Parikh＇s quantum tunneling model, we study the quantum tunneling radiation of Reissne- Nordstrom de Sitter black hole with a global monopole. The result shows that the tunneling rates at the event horizon and the cosmic horizon are related to Bekenstein-Hawking entropy if we take the energy conservation into consideration, and the true radiate spectrum is not precisely thermal.
文摘The paper studies the form invariance and a type of non-Noether conserved quantity called Mei conserved quantity for non-holonomic systems with variable mass and unilateral constraints. Acoording to the invariance of the form of differential equations of motion under infinitesimal transformations, this paper gives the definition and criterion of the form invariance for non-holonomic systems with variable mass and unilateral constraints. The condition under which a form invariance can lead to Mei conservation quantity and the form of the conservation quantity are deduced. An example is given to illustrate the application of the results.
基金Supported by National Natural Science Foundation of China under Grant No. 10972151the Natural Science Foundation of Higher Education Institution of Jiangsu Province under Grant No. 08KJB130002
文摘This paper focuses on studying a conformal invariance and a Noether symmetry, a Lie symmetry for a Birkhoffian system in event space. The definitions of the conformal invariance of the system are given. By investigation on the relations between the conformal invariance and the Noether symmetry, the conformal invariance and the Lie symmetry, the expressions of conformal factors of the system under these circumstances are obtained. The Noether conserved quantities and the Hojman conserved quantities directly derived from the conformal invariance are given. Two examples are given to illustrate the application of the results.
文摘The current study explores how the ideological struggle is unfolded in the movie Forrest Gump （1994）. Through a critical examination of the text structure of the plot and the language used by four main characters, it demonstrates that conservatism has gained great victory over liberalism in the following way： Those with conservative values are highlighted repeatedly in a favorable way, while those who preach liberal values are frequently associated with tragic events, and ultimately, the latter all converted into conservatives in one way or another, which indicates a reconciliation between the two opposing ideologies. This study might shed light on how visual media can be geared towards political justifications, and bring audience to the level of conscious awareness of that effect
文摘AIM:To investigate the clinicopathologic features of bile duct tumor thrombus(BDTT) occurrence after treatment of primary small hepatocellular carcinoma(sHCC) .METHODS:A total of 423 patients with primary sHCC admitted to our hospital underwent surgical resection or local ablation.During follow-up,only six patients were hospitalized due to obstructive jaundice,which occurred 5-76 mo after initial treatment.The clinicopathologic features of these six patients were reviewed.RESULTS:Six patients underwent hepatic resection(n=5) or radio-frequency ablation(n=1) due to primary sHCC.Five cases had an R1 resection margin,and one case had an ablative margin less than 5.0 mm.No vascular infiltration,microsatellites or bile duct/canaliculus affection was noted in the initial resected specimens.During the follow-up,imaging studies revealed a macroscopic BDTT extending to the common bile duct in all six patients.Four patients had a concomitant intrahepatic recurrent tumor.Surgical re-resection of intrahepatic recurrent tumors and removal of BDTTs(n=4) ,BDTT removal through choledochotomy(n= 1) ,and conservative treatment(n=1) was performed.Microscopic portal vein invasion was noted in three of the four resected specimens.All six patients died,with a mean survival of 11 mo after BDTT removal or conservative treatment.CONCLUSION:BDTT occurrence is a rare,special recurrent pattern of primary sHCC.Patients with BDTTs extending to the common bile duct usually have an unfavorable prognosis even following aggressive surgery.Insufficient resection or ablative margins against primary sHCC may be a risk factor for BDTT development.
基金Supported by the Graduate Students' Innovative Foundation of China University of Petrolem (East China) under Grant No.S2009-19
文摘Conformal invariance and a new type of conserved quantities of mechanical systems with variable mass in phase space are studied. Firstly, the definition and determining equation of conformal invariance are presented. The relationship between the conformal invariance and the Lie symmetry is given, and the necessary and sufficient condition that the conformal invarianee would be the Lie symmetry under the infinitesimal transformations is provided. Secondly, a new type of conserved quantities of the conformal invariance are obtained by using the Lie symmetry of the system. Lastly, an example is given to illustrate the application of the results.
文摘Experiment investigations on crack propagation of silver based contact surface are carried out with various currents and contact closed forces.It is found that crack propagation of contact surface is caused by arc energy and contact closed forces.Meanwhile, the energy equilibrium equation of crack propagation of silver based contact material under arc energy and contact closed force is provided.
基金supported by the National Basic Research Program of China(Grant No.2009CB724304)the National Key Technology R&D Program(Grant No.2011BAF09B05)+1 种基金the National Natural Science Foundation of China(Grant No.50975157)the Key Research Program of the State Key Laboratory of Tribology of Tsinghua University(Grant No.SKLT08A06)
文摘A mass-conservative average flow model based on the finite element method(FEM) is introduced to predict the performances of textured surfaces applied in mechanical seals or thrust bearings.In this model,the Jakobsson-Floberg-Olsson(JFO) boundary conditions are applied to the average flow model for ensuring the mass-conservative law.Moreover,the non-uniform triangular grid is utilized,which can deal with the problem of complex geometric shapes.By adopting the modeling techniques,the model proposed here is capable of dealing with complex textured surfaces.The algorithm is proved correct by the numerical experiment.In addition,the model is employed to gain further insight into the influences of the dimples with different shapes and orientations on smooth and rough surfaces on the load-carrying capacity.
基金supported by the National Natural Science Foundation of China under Grant Nos.10771072 and 11071274
文摘Based on Wu＇s elimination method and ＂divide-and-conquer＂ strategy, the undetermined coefficient algorithm to construct polynomial form conservation laws for nonlinear differential-difference equations （DDEs） is improved. Furthermore, a Maple package named CLawDDEs, which can entirely automatically derive polynomial form conservation laws of nonlinear DDEs is presented. The effective- ness of CLawDDEs is demonstrated by application to different kinds of examples.
基金supported by the National Natural Science Foundation of China(Grant No.11105053)the Open Research Foundation of Shanghai Key Laboratory of Particle Physics and Cosmology(Grant No.11DZ2230700)
文摘Inspired by Verlinde’s idea,some modified versions of entropic gravity have been suggested.Extending them in a unified formalism,herein we derive the generalized gravitational equations accordingly.From gravitational equations,the energy-momentum conservation law and cosmological equations are investigated.The covariant conservation law of energy-momentum tensor severely constrains viable modifications of entropic gravity.A discrepancy arises when two independent methods are applied to the homogeneous isotropic universe,posing a serious challenge to modified models of entropic gravity.
文摘Although the degree of mate competition, given extreme differences in sex ratio, explains much of the pattern of male-biased size dimorphism among diverse taxa, it fails for some species which have potential for intense male competition for mates and yet exhibit little or no sexual size dimorphism （SSD）. This fact suggest that species with low SSD should be express the effect of evolutionary pressure in non-obvious geometrical shape promoted by sex ratio in an evolutionary time scale. To evaluate this hypothesis we used phylogenetic comparative method in a Bayesian framework to investigate the evolution of SSD and the role of sex ratio at inter-specific level in the species of Ceroglossus （Coleoptera： Carabidae）. In our results the proportion farthest from 1：1 is associated with more disparate body shape, even though the entire group has minimum variation in sex ratio, which is an intrinsic life history character of this group considering its phylogenetic conservatism or phylogenetic signal. We suggest that the sex ratio has determined the dimorphism degree during evolution of this group, since both traits have increased or decreased together during the species divergence （i.e. positive phylogenetic correlation： r2=0.85）. We suggest that morphological studies of SSD will benefit from using comparative method with Bayesian approaches to assess the effect of phylogenetic history and its uncertainty. Finally, this will be allow to researchers to quantify the uncertainty of specific evolutionary hypotheses accounting for observed sexual dimorphism patterns.
