Sintered silver nanoparticles(AgNPs)arewidely used in high-power electronics due to their exceptional properties.However,the material reliability is significantly affected by various microscopic defects.In this work,t...Sintered silver nanoparticles(AgNPs)arewidely used in high-power electronics due to their exceptional properties.However,the material reliability is significantly affected by various microscopic defects.In this work,the three primary micro-defect types at potential stress concentrations in sintered AgNPs are identified,categorized,and quantified.Molecular dynamics(MD)simulations are employed to observe the failure evolution of different microscopic defects.The dominant mechanisms responsible for this evolution are dislocation nucleation and dislocation motion.At the same time,this paper clarifies the quantitative relationship between the tensile strain amount and the failure mechanism transitions of the three defect types by defining key strain points.The impact of defect types on the failure process is also discussed.Furthermore,traction-separation curves extracted from microscopic defect evolutions serve as a bridge to connect the macro-scale model.The validity of the crack propagation model is confirmed through tensile tests.Finally,we thoroughly analyze how micro-defect types influence macro-crack propagation and attempt to find supporting evidence from the MD model.Our findings provide a multi-perspective reference for the reliability analysis of sintered AgNPs.展开更多
Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)is an excellent investigation to diagnose pancreatic lesions and has shown high accuracy for its use in pathologic diagnosis.Recently,macroscopic on-site evaluat...Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)is an excellent investigation to diagnose pancreatic lesions and has shown high accuracy for its use in pathologic diagnosis.Recently,macroscopic on-site evaluation(MOSE)performed by an endoscopist was introduced as an alternative to rapid on-site cytologic evaluation to increase the diagnostic yield of EUS-FNB.The MOSE of the biopsy can estimate the adequacy of the sample directly by the macroscopic evaluation of the core tissue obtained from EUS-FNB.Isolated pancreatic tuberculosis is extremely rare and difficult to diagnose because of its non-specific signs and symptoms.Therefore,this challenging diagnosis is based on endoscopy,imaging,and the bacteriological and histological examination of tissue biopsies.This uncommon presentation of tuberculosis can be revealed as pancreatic mass mimicking cancer.EUS-FNB can be very useful in providing a valuable histopathological diagnosis.A calcified lesion with a cheesy core in MOSE must be suggestive of tuberculosis,leading to the request of the GeneXpert,which can detect Mycobacterium tuberculosis deoxyribonucleic acid and resistance to rifampicin.A decent diagnostic strategy is crucial to prevent unnecessary surgical resection and to supply conservative management with antitubercular therapy.展开更多
An industrial plant trial for optimizing the process parameters in a round billet continuous casting mold with electromagnetic stirring (M-EMS) was performed, in which the influences of stirring parameters with M-EM...An industrial plant trial for optimizing the process parameters in a round billet continuous casting mold with electromagnetic stirring (M-EMS) was performed, in which the influences of stirring parameters with M-EMS on the solidification macrostructure of high carbon steel were investigated. The results show that the billet quality is not well controlled under the condition of working current and frequency with EMS, in which the subsurface crack of grade 1.0-2.0 ups to 38.09%, the central pipe of grade 1.0-1.5 reaches to 14.28%, and the central porosity of grade 1.5 is 14.29%. The parameters of current 260 A and frequency 8 Hz as the final optimum scheme has a remarkable effect for improving the macroscopic quality of billet, in which the subsurface crack, central pipe and skin blowhole are all disappeared, and the central porosity and carbon segregation are also well improved.展开更多
Nanocarbon-based materials, such as carbon nanotubes(CNTs) and graphene have been attached much attention by scientific and industrial community. As two representative nanocarbon materials, one-dimensional CNTs and tw...Nanocarbon-based materials, such as carbon nanotubes(CNTs) and graphene have been attached much attention by scientific and industrial community. As two representative nanocarbon materials, one-dimensional CNTs and twodimensional graphene both possess remarkable mechanical properties. In the past years, a large amount of work have been done by using CNTs or graphene as building blocks for constructing novel, macroscopic, mechanically strong fibrous materials. In this review, we summarize the assembly approaches of CNT-based fibers and graphene-based fibers in chronological order, respectively. The mechanical performances of these fibrous materials are compared, and the critical influences on the mechanical properties are discussed. Personal perspectives on the fabrication methods of CNT-and graphene-based fibers are further presented.展开更多
In the presence of inhibitors, the macroscopical oxidation kinetics of calcium sulfite, the main byproduct in wet limestone scrubbing, was studied for the first time by adding different inhibitors and varying pH, conc...In the presence of inhibitors, the macroscopical oxidation kinetics of calcium sulfite, the main byproduct in wet limestone scrubbing, was studied for the first time by adding different inhibitors and varying pH, concentration of calcium sulfite, oxygen partial pressure, concentration of inhibitors and temperature. The mathematical model about the general oxidation reaction was established, which was controlled by three steps involving dissolution of calcium sulfite, mass transfer of oxygen and chemical reaction in the solution. It was concluded that the general reaction was controlled by mass transfer of oxygen under uncatalyzed conditions, while it was controlled by dissolution of calcium sulfite after adding three kinds of inhibitors. Thus, the theory was provided for investigating the mechanism and oxidation kinetics of sulfite. The beneficial references were also supplied for design of oxidation technics in the wet limestone scrubbing.展开更多
Recent experiments revealed many new phenomena of the macroscopic domain patterns in the stress-induced phase transformation of a superelastic polycrystalline NiTi tube during tensile loading. The new phenomena includ...Recent experiments revealed many new phenomena of the macroscopic domain patterns in the stress-induced phase transformation of a superelastic polycrystalline NiTi tube during tensile loading. The new phenomena include deformation instability with the formation of a helical domain, domain topology transition from helix to cylinder, domain-front branching and loading-path dependence of domain patterns. In this paper, we model the polycrystal as an elastic continuum with nonconvex strain energy and adopt the non-local strain gradient energy to account for the energy of the diffusive domain front. We simulate the equilibrium domain patterns and their evolution in the tubes under tensile loading by a non-local Finite Element Method (FEM). It is revealed that the observed loading-path dependence and topology transition of do- main patterns are due to the thermodynamic metastability of the tube system. The computation also shows that the tube-wall thickness has a significant effect on the domain patterns: with fixed material properties and interfacial energy density, a large tube-wall thickness leads to a long and slim helical domain and a severe branching of the cylindrical-domain front.展开更多
Intrahepatic cholangiocarcinoma is macroscopically classified into three subtypes, mass-forming-type, periductal infiltrating-type, and intraductal growth-type. Each subtype should be preoperatively differentiated to ...Intrahepatic cholangiocarcinoma is macroscopically classified into three subtypes, mass-forming-type, periductal infiltrating-type, and intraductal growth-type. Each subtype should be preoperatively differentiated to perform the valid surgical resection. Recent researches have revealed the clinical, radiologic, pathobiological characteristics of each subtype. We reviewed recently published studies covering various aspects of intrahepatic cholangiocarcinoma(ICC), focusing especially on the macroscopic subtypes and stem cell features to better understand the pathophysiology of ICC and to establish the valid therapeutic strategy.展开更多
AIM To evaluate whether a high risk macroscopic appearance(Type Ⅳ and giant Type Ⅲ) is associated with a dismal prognosis after curative surgery, because its prognostic relevance remains elusive in pathological sta...AIM To evaluate whether a high risk macroscopic appearance(Type Ⅳ and giant Type Ⅲ) is associated with a dismal prognosis after curative surgery, because its prognostic relevance remains elusive in pathological stage Ⅱ/Ⅲ(p Stage Ⅱ/Ⅲ) gastric cancer.METHODS One hundred and seventy-two advanced gastric cancer(defined as pT2 or beyond) patients with p Stage Ⅱ/Ⅲ who underwent curative surgery plus adjuvant S1 chemotherapy were evaluated, and the prognostic relevance of a high-risk macroscopic appearance was examined. RESULTS Advanced gastric cancers with a high-risk macroscopic appearance were retrospectively identified by preoperative recorded images. A high-risk macroscopic appearance showed a significantly worse relapse free survival(RFS)(35.7%) and overall survival(OS)(34%) than an average risk appearance(P = 0.0003 and P < 0.0001, respectively). A high-risk macroscopic appearance was significantly associated with the 13^(th) Japanese Gastric Cancer Association(JGCA) pT(P = 0.01), but not with the 13^(th) JGCA pN. On univariate analysis for RFS and OS, prognostic factors included 13^(th) JGCA p Stage(P < 0.0001)and other clinicopathological factors including macroscopic appearance. A multivariate Cox proportional hazards model for univariate prognostic factors identified highrisk macroscopic appearance(P = 0.036, HR = 2.29 for RFS and P = 0.021, HR = 2.74 for OS) as an independent prognostic indicator. CONCLUSION A high-risk macroscopic appearance was associated with a poor prognosis, and it could be a prognostic factor independent of 13^(th) JGCA stage in p Stage Ⅱ/Ⅲ advanced gastric cancer.展开更多
The evolution of gas bearing channels in the roof,and their spatial distribution,was studied.A complete consideration of gas flow changes through the stress-strain changes in the roof near a working face is made.The t...The evolution of gas bearing channels in the roof,and their spatial distribution,was studied.A complete consideration of gas flow changes through the stress-strain changes in the roof near a working face is made.The theoretical abutment pressure distribution using displacement monitors and borehole visual recording instruments allow a theoretical analysis.Field test research determined the conditions for formation of macroscopic gas channels.These appear along the working face roof,normally distributed to it.These results show that the coal rock stratification becomes a macroscopic gas channel boundary if its deformation is less than the lower layer,or greater than the layer above it.At the same time the stability is greater than the distance from the roof for hanging dew conditions.The working face advances and the roof gas channels experience a cycle of development.Microscopic channels dominate the initial stage then macroscopic gas channels form,develop,and close.The evolution of the macroscopic channels depends on the ratio between the distances from the new compaction area in the goaf to the initial stress area in front of the working face.The amount of daily advance of the face also affects channel development.The experimental observations in one mining area showed that the main gas channels are located about 2 and 6.2 m above the lower surface of the roof and that they have an evolution period 7 to 11 days long.展开更多
We have observed the macroscopic resonant tunneling of magnetic flux between macroscopically distinct quantum states in a superconducting flux qubit. The dependences of the macroscopic resonant tunneling on the barrie...We have observed the macroscopic resonant tunneling of magnetic flux between macroscopically distinct quantum states in a superconducting flux qubit. The dependences of the macroscopic resonant tunneling on the barrier height of the potential well, the flux bias and the initial state are investigated. Detailed measurements of the tunneling rate as a function of the flux bias reveal the feature of the quantum noise in the superconducting flux qubit.展开更多
A traffic model based on the road surface conditions during adverse weather is presented. The surface of a road is affected by snow, compacted snow, and ice, which affects the traffic behavior. In this paper, a new ma...A traffic model based on the road surface conditions during adverse weather is presented. The surface of a road is affected by snow, compacted snow, and ice, which affects the traffic behavior. In this paper, a new macroscopic traffic flow model based on the transition velocity distribution is proposed which characterizes traffic alignment under adverse weather conditions. Two examples are considered to illustrate the effect of the transition velocity behavior on traffic velocity and density. Simulation results are presented which show that this model provides a more accurate characterization of traffic flow behavior than the well known Payne-Whitham model. The proposed model can be used to reduce accidents and improve road safety during adverse weather conditions.展开更多
Hydrophobic interactions have been studied before in detail based on hydrophobic polymers,such as polystyrene(PS).Because fluorinated materials have relatively low surface energy,they often show both oleophobicity and...Hydrophobic interactions have been studied before in detail based on hydrophobic polymers,such as polystyrene(PS).Because fluorinated materials have relatively low surface energy,they often show both oleophobicity and hydrophobicity at the macroscopic level.However,it remains unknown how fluorination of hydrophobic polymer influences hydrophobicity at the microscopic level.We synthesized PS and fluorine-substituted PS(FPS)by employing the reversible addition-fragmentation chain transfer polymerization method.Contact angle measurements confirmed that FPS is more hydrophobic than PS at the macroscopic level due to the introduction of fluorine.However,single molecule force spectroscopy experiments showed that the forces required to unfold the PS and FPS nanoparticles in water are indistinguishable,indicating that the strength of the hydrophobic effect that drives the self-assembly of PS and FPS nanoparticles is the same at the microscopic level.The divergence of hydrophobic effect at the macroscopic and microscopic level may hint different underlying mechanisms:the hydrophobicity is dominated by the solvent hydration at the microscopic level and the surface-associated interaction at the macroscopic level.展开更多
The regularity of solutions to the Boltzmann equation is a fundamental problem in the kinetic theory. In this paper, the case with angular cut-off is investigated. It is shown that the macroscopic parts of solutions t...The regularity of solutions to the Boltzmann equation is a fundamental problem in the kinetic theory. In this paper, the case with angular cut-off is investigated. It is shown that the macroscopic parts of solutions to the Boltzmann equation, i.e., the density, momentum and total energy are continuous functions of (x, t) in the region R3 × (0, +∞). More precisely, these macroscopic quantities immediately become continuous in any positive time even though they are initially discontinuous and the discontinuities of solutions propagate only in the microscopic level. It should be noted that such kind of phenomenon can not hap- pen for the compressible Navier-Stokes equations in which the initial discontinuities of the density never vanish in any finite time, see [22]. This hints that the Boltzmann equation has better regularity effect in the macroscopic level than compressible Navier-Stokes equations.展开更多
Based on the Hertzian granular contact mechanics model, the paper built up a Macroscopic Young’s Elastic Modulus of particle/granular packing rock layers, and built up a ties to connecting Young’s Elastic Modulus of...Based on the Hertzian granular contact mechanics model, the paper built up a Macroscopic Young’s Elastic Modulus of particle/granular packing rock layers, and built up a ties to connecting Young’s Elastic Modulus of sand particle in Meso and the Macroscopic Young’s Modulus of granular packing rock layers. The Macroscopic Young’s Modulus of granular packing rock layers is far less than the Young’s Modulus of sand particle. The Macroscopic Young’s Modulus of granular packing rock layers is proportioned to the powers of 1/3 of the vertical contact force of sand particles. The Macroscopic Young’s Modulus is inversely proportional to particle diameter. The paper calculated the vertical contact force of five types aligning mode of the particles. When equal stress, the increased of the coordination number lead to the decrease of the contact force fn, this lead to the coordination number is an inverse proportion to Macroscopic Young’s Modulus. But the larger coordination number change only means very little Macroscopic Young’s Modulus change.展开更多
The focusing and the stable transport of an intense elliptic sheet electron beam in a uniform magnetic field are investigated thoroughly by using the macroscopic cold-fluid model and the single-particle orbit theory.T...The focusing and the stable transport of an intense elliptic sheet electron beam in a uniform magnetic field are investigated thoroughly by using the macroscopic cold-fluid model and the single-particle orbit theory.The results indicate that the envelopes and the tilted angles of the sheet electron beam obtained by the two theories are consistent.The single-particle orbit theory is more accurate due to its treatment of the space-charge fields in a rectangular drift tube.The macroscopic cold-fluid model describes the collective transport process in order to provide detailed information about the beam dynamics,such as beam shape,density,and velocity profile.The tilt of the elliptic sheet beam in a uniform magnetic field is carefully studied and demonstrated.The results presented in this paper provide two complete theories for systemically discussing the transport of the sheet beam and are useful for understanding and guiding the practical engineering design of electron optics systems in high power vacuum electronic devices.展开更多
We propose a feasible scheme to generate electromagnetically induced transparency(EIT) and quadripartite macroscopic entanglement in an optomechanical system with one fixed mirror and three movable perfectly reflect...We propose a feasible scheme to generate electromagnetically induced transparency(EIT) and quadripartite macroscopic entanglement in an optomechanical system with one fixed mirror and three movable perfectly reflecting mirrors.We explore the EIT phenomena in this optomechanical system.Results show the appearance of EIT dips in the output field.Moreover,we demonstrate how steady-state quadripartite entanglement can be generated via radiation pressure.We also quantify the bipartite entanglement in each field-mirror subsystem and in the mirror-mirror subsystem.Findings show that a high intensity of entanglement between two subsystems can be achieved.展开更多
Detailed micro-meso to macroscopic structural analyses reveal two deformation phases in the western limb of the Hazara-Kashmir Syntaxis(HKS). Bulk top to NW shearing transformed initially symmetrical NNE-SSW trendin...Detailed micro-meso to macroscopic structural analyses reveal two deformation phases in the western limb of the Hazara-Kashmir Syntaxis(HKS). Bulk top to NW shearing transformed initially symmetrical NNE-SSW trending meso to macroscopic folds from asymmetric to overturned ones without changing their trend. Sigmoidal en-echelon tension gashes developed during this deformation,that were oblique to bedding parallel worm burrows and bedding planes themselves. Strain analyses of deformed elliptical ooids using the Rf/Ф method constrain the internal strain patterns of the NNE-SSW structures. The principal stretching axis(S3) defined by deformed elliptical ooids is oriented N27°E at right angles to WNW-ESE shortening. The deformed elliptical ooids in sub-vertical bedding vertical planes contain ooids that plunge -70° SE due to NW-directed tectonic transport. Finite strain ratios are1.45(Rxy) parallel to bedding plane and 1.46(Ryz) for the vertical plane. From these 2D strain values, we derive an oblate strain ellipsoidal in 3D using the Flinn and Hsu/Nadai techniques. Strains calculated from deformed elliptical ooids average-18.10% parallel to bedding and-18.47% in the vertical plane.However, a balanced cross-section through the study area indicates a minimum of--28% shortening.Consequently, regional shortening was only partially accommodated by internal deformation.展开更多
In this paper,a derivation of the macroscopic mean field theory of the cellular automaton(CA)model of highway traffic flow starting from the microscopic dynamical point of view is presented.Starting from an equation d...In this paper,a derivation of the macroscopic mean field theory of the cellular automaton(CA)model of highway traffic flow starting from the microscopic dynamical point of view is presented.Starting from an equation describing the time evolution of the Boolean state variable at each site of the basic CA model,and using a two-site approximation for the multi-site correlation functions,a dynamical mapping between the macroscopic average speeds v(t+1)and v(t)at different time can be derived.Mean field results consistent with the simulation data are obtained by considering the attractors of the mapping and their corresponding basins.展开更多
We study how the decoherence of macroscopic objects originates intrinsically from the relativistic effect. With the degree of freedom of the center of mass(CM) characterizing the collective quantum state of a macros...We study how the decoherence of macroscopic objects originates intrinsically from the relativistic effect. With the degree of freedom of the center of mass(CM) characterizing the collective quantum state of a macroscopic object(MO),it is found that an MO consisting of N particles can decohere with a time scale of no more than p (√N)^-1. Here, the special relativity can induce the coupling of the collective motion mode and the relative motion modes in an order of 1/c^2, which intrinsically results in the above minimum decoherence.展开更多
In this paper, we adopt the coarse graining method proposed by Lee H K et al. to develop a macroscopic model from the microscopic traffic model-GOVM. The proposed model inherits the parameter p which considers the inf...In this paper, we adopt the coarse graining method proposed by Lee H K et al. to develop a macroscopic model from the microscopic traffic model-GOVM. The proposed model inherits the parameter p which considers the influence of next-nearest car introduced in the GOVM model. The simulation results show that the new model is strictly consistent with the former microscopic model. Using this macroscopic model, we can avoid considering the details of each traffic on the road, and build more complex models such as road network model easily in the future.展开更多
基金supported by the China Scholarship Council (CSC) (No.202206020149)the Academic Excellence Foundation of BUAA for PhD Students,the Funding Project of Science and Technology on Reliability and Environmental Engineering Laboratory (No.6142004210106).
文摘Sintered silver nanoparticles(AgNPs)arewidely used in high-power electronics due to their exceptional properties.However,the material reliability is significantly affected by various microscopic defects.In this work,the three primary micro-defect types at potential stress concentrations in sintered AgNPs are identified,categorized,and quantified.Molecular dynamics(MD)simulations are employed to observe the failure evolution of different microscopic defects.The dominant mechanisms responsible for this evolution are dislocation nucleation and dislocation motion.At the same time,this paper clarifies the quantitative relationship between the tensile strain amount and the failure mechanism transitions of the three defect types by defining key strain points.The impact of defect types on the failure process is also discussed.Furthermore,traction-separation curves extracted from microscopic defect evolutions serve as a bridge to connect the macro-scale model.The validity of the crack propagation model is confirmed through tensile tests.Finally,we thoroughly analyze how micro-defect types influence macro-crack propagation and attempt to find supporting evidence from the MD model.Our findings provide a multi-perspective reference for the reliability analysis of sintered AgNPs.
文摘Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)is an excellent investigation to diagnose pancreatic lesions and has shown high accuracy for its use in pathologic diagnosis.Recently,macroscopic on-site evaluation(MOSE)performed by an endoscopist was introduced as an alternative to rapid on-site cytologic evaluation to increase the diagnostic yield of EUS-FNB.The MOSE of the biopsy can estimate the adequacy of the sample directly by the macroscopic evaluation of the core tissue obtained from EUS-FNB.Isolated pancreatic tuberculosis is extremely rare and difficult to diagnose because of its non-specific signs and symptoms.Therefore,this challenging diagnosis is based on endoscopy,imaging,and the bacteriological and histological examination of tissue biopsies.This uncommon presentation of tuberculosis can be revealed as pancreatic mass mimicking cancer.EUS-FNB can be very useful in providing a valuable histopathological diagnosis.A calcified lesion with a cheesy core in MOSE must be suggestive of tuberculosis,leading to the request of the GeneXpert,which can detect Mycobacterium tuberculosis deoxyribonucleic acid and resistance to rifampicin.A decent diagnostic strategy is crucial to prevent unnecessary surgical resection and to supply conservative management with antitubercular therapy.
基金supported by the Program for New Century Excellent Talents in University from the Ministry of Education of China (No.NCET-04-0285)
文摘An industrial plant trial for optimizing the process parameters in a round billet continuous casting mold with electromagnetic stirring (M-EMS) was performed, in which the influences of stirring parameters with M-EMS on the solidification macrostructure of high carbon steel were investigated. The results show that the billet quality is not well controlled under the condition of working current and frequency with EMS, in which the subsurface crack of grade 1.0-2.0 ups to 38.09%, the central pipe of grade 1.0-1.5 reaches to 14.28%, and the central porosity of grade 1.5 is 14.29%. The parameters of current 260 A and frequency 8 Hz as the final optimum scheme has a remarkable effect for improving the macroscopic quality of billet, in which the subsurface crack, central pipe and skin blowhole are all disappeared, and the central porosity and carbon segregation are also well improved.
基金supported by the National Natural Science Foundation of China (Nos. 21325417, 51533008)the MOST National Key Research and Development Plan (2016YFA0200200)+1 种基金the National Postdoctoral Program for Innovative Talents (No. BX201700209)the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University (No. LK1403)
文摘Nanocarbon-based materials, such as carbon nanotubes(CNTs) and graphene have been attached much attention by scientific and industrial community. As two representative nanocarbon materials, one-dimensional CNTs and twodimensional graphene both possess remarkable mechanical properties. In the past years, a large amount of work have been done by using CNTs or graphene as building blocks for constructing novel, macroscopic, mechanically strong fibrous materials. In this review, we summarize the assembly approaches of CNT-based fibers and graphene-based fibers in chronological order, respectively. The mechanical performances of these fibrous materials are compared, and the critical influences on the mechanical properties are discussed. Personal perspectives on the fabrication methods of CNT-and graphene-based fibers are further presented.
基金The National Basic Research Program(973) of China(No. JK00020)
文摘In the presence of inhibitors, the macroscopical oxidation kinetics of calcium sulfite, the main byproduct in wet limestone scrubbing, was studied for the first time by adding different inhibitors and varying pH, concentration of calcium sulfite, oxygen partial pressure, concentration of inhibitors and temperature. The mathematical model about the general oxidation reaction was established, which was controlled by three steps involving dissolution of calcium sulfite, mass transfer of oxygen and chemical reaction in the solution. It was concluded that the general reaction was controlled by mass transfer of oxygen under uncatalyzed conditions, while it was controlled by dissolution of calcium sulfite after adding three kinds of inhibitors. Thus, the theory was provided for investigating the mechanism and oxidation kinetics of sulfite. The beneficial references were also supplied for design of oxidation technics in the wet limestone scrubbing.
文摘Recent experiments revealed many new phenomena of the macroscopic domain patterns in the stress-induced phase transformation of a superelastic polycrystalline NiTi tube during tensile loading. The new phenomena include deformation instability with the formation of a helical domain, domain topology transition from helix to cylinder, domain-front branching and loading-path dependence of domain patterns. In this paper, we model the polycrystal as an elastic continuum with nonconvex strain energy and adopt the non-local strain gradient energy to account for the energy of the diffusive domain front. We simulate the equilibrium domain patterns and their evolution in the tubes under tensile loading by a non-local Finite Element Method (FEM). It is revealed that the observed loading-path dependence and topology transition of do- main patterns are due to the thermodynamic metastability of the tube system. The computation also shows that the tube-wall thickness has a significant effect on the domain patterns: with fixed material properties and interfacial energy density, a large tube-wall thickness leads to a long and slim helical domain and a severe branching of the cylindrical-domain front.
文摘Intrahepatic cholangiocarcinoma is macroscopically classified into three subtypes, mass-forming-type, periductal infiltrating-type, and intraductal growth-type. Each subtype should be preoperatively differentiated to perform the valid surgical resection. Recent researches have revealed the clinical, radiologic, pathobiological characteristics of each subtype. We reviewed recently published studies covering various aspects of intrahepatic cholangiocarcinoma(ICC), focusing especially on the macroscopic subtypes and stem cell features to better understand the pathophysiology of ICC and to establish the valid therapeutic strategy.
文摘AIM To evaluate whether a high risk macroscopic appearance(Type Ⅳ and giant Type Ⅲ) is associated with a dismal prognosis after curative surgery, because its prognostic relevance remains elusive in pathological stage Ⅱ/Ⅲ(p Stage Ⅱ/Ⅲ) gastric cancer.METHODS One hundred and seventy-two advanced gastric cancer(defined as pT2 or beyond) patients with p Stage Ⅱ/Ⅲ who underwent curative surgery plus adjuvant S1 chemotherapy were evaluated, and the prognostic relevance of a high-risk macroscopic appearance was examined. RESULTS Advanced gastric cancers with a high-risk macroscopic appearance were retrospectively identified by preoperative recorded images. A high-risk macroscopic appearance showed a significantly worse relapse free survival(RFS)(35.7%) and overall survival(OS)(34%) than an average risk appearance(P = 0.0003 and P < 0.0001, respectively). A high-risk macroscopic appearance was significantly associated with the 13^(th) Japanese Gastric Cancer Association(JGCA) pT(P = 0.01), but not with the 13^(th) JGCA pN. On univariate analysis for RFS and OS, prognostic factors included 13^(th) JGCA p Stage(P < 0.0001)and other clinicopathological factors including macroscopic appearance. A multivariate Cox proportional hazards model for univariate prognostic factors identified highrisk macroscopic appearance(P = 0.036, HR = 2.29 for RFS and P = 0.021, HR = 2.74 for OS) as an independent prognostic indicator. CONCLUSION A high-risk macroscopic appearance was associated with a poor prognosis, and it could be a prognostic factor independent of 13^(th) JGCA stage in p Stage Ⅱ/Ⅲ advanced gastric cancer.
基金provided by the State Key BasicResearch Program of China(No.2011CB201204)the National Natural Science Foundation of China(Nos.51204187 and 51234005)
文摘The evolution of gas bearing channels in the roof,and their spatial distribution,was studied.A complete consideration of gas flow changes through the stress-strain changes in the roof near a working face is made.The theoretical abutment pressure distribution using displacement monitors and borehole visual recording instruments allow a theoretical analysis.Field test research determined the conditions for formation of macroscopic gas channels.These appear along the working face roof,normally distributed to it.These results show that the coal rock stratification becomes a macroscopic gas channel boundary if its deformation is less than the lower layer,or greater than the layer above it.At the same time the stability is greater than the distance from the roof for hanging dew conditions.The working face advances and the roof gas channels experience a cycle of development.Microscopic channels dominate the initial stage then macroscopic gas channels form,develop,and close.The evolution of the macroscopic channels depends on the ratio between the distances from the new compaction area in the goaf to the initial stress area in front of the working face.The amount of daily advance of the face also affects channel development.The experimental observations in one mining area showed that the main gas channels are located about 2 and 6.2 m above the lower surface of the roof and that they have an evolution period 7 to 11 days long.
基金Project supported by the New Century Excellent Talents in University,Chinathe National Natural Science Foundation of China(Grant Nos. 11074114 and 10874074)the National Basic Research Program of China (Grant No. 2011CBA00200)
文摘We have observed the macroscopic resonant tunneling of magnetic flux between macroscopically distinct quantum states in a superconducting flux qubit. The dependences of the macroscopic resonant tunneling on the barrier height of the potential well, the flux bias and the initial state are investigated. Detailed measurements of the tunneling rate as a function of the flux bias reveal the feature of the quantum noise in the superconducting flux qubit.
基金Project supported by Higher Education Commission,Pakistan/National Center of Big Data and Cloud Computing
文摘A traffic model based on the road surface conditions during adverse weather is presented. The surface of a road is affected by snow, compacted snow, and ice, which affects the traffic behavior. In this paper, a new macroscopic traffic flow model based on the transition velocity distribution is proposed which characterizes traffic alignment under adverse weather conditions. Two examples are considered to illustrate the effect of the transition velocity behavior on traffic velocity and density. Simulation results are presented which show that this model provides a more accurate characterization of traffic flow behavior than the well known Payne-Whitham model. The proposed model can be used to reduce accidents and improve road safety during adverse weather conditions.
基金supported by the National Key R&D Program of China(Grant No.2020YFA0908100)。
文摘Hydrophobic interactions have been studied before in detail based on hydrophobic polymers,such as polystyrene(PS).Because fluorinated materials have relatively low surface energy,they often show both oleophobicity and hydrophobicity at the macroscopic level.However,it remains unknown how fluorination of hydrophobic polymer influences hydrophobicity at the microscopic level.We synthesized PS and fluorine-substituted PS(FPS)by employing the reversible addition-fragmentation chain transfer polymerization method.Contact angle measurements confirmed that FPS is more hydrophobic than PS at the macroscopic level due to the introduction of fluorine.However,single molecule force spectroscopy experiments showed that the forces required to unfold the PS and FPS nanoparticles in water are indistinguishable,indicating that the strength of the hydrophobic effect that drives the self-assembly of PS and FPS nanoparticles is the same at the microscopic level.The divergence of hydrophobic effect at the macroscopic and microscopic level may hint different underlying mechanisms:the hydrophobicity is dominated by the solvent hydration at the microscopic level and the surface-associated interaction at the macroscopic level.
基金partially supported by by National Center for Mathematics and Interdisciplinary Sciences,AMSS,CAS and NSFC(11371349 and 11688101)partially supported by NSFC(11688101,11771429)
文摘The regularity of solutions to the Boltzmann equation is a fundamental problem in the kinetic theory. In this paper, the case with angular cut-off is investigated. It is shown that the macroscopic parts of solutions to the Boltzmann equation, i.e., the density, momentum and total energy are continuous functions of (x, t) in the region R3 × (0, +∞). More precisely, these macroscopic quantities immediately become continuous in any positive time even though they are initially discontinuous and the discontinuities of solutions propagate only in the microscopic level. It should be noted that such kind of phenomenon can not hap- pen for the compressible Navier-Stokes equations in which the initial discontinuities of the density never vanish in any finite time, see [22]. This hints that the Boltzmann equation has better regularity effect in the macroscopic level than compressible Navier-Stokes equations.
文摘Based on the Hertzian granular contact mechanics model, the paper built up a Macroscopic Young’s Elastic Modulus of particle/granular packing rock layers, and built up a ties to connecting Young’s Elastic Modulus of sand particle in Meso and the Macroscopic Young’s Modulus of granular packing rock layers. The Macroscopic Young’s Modulus of granular packing rock layers is far less than the Young’s Modulus of sand particle. The Macroscopic Young’s Modulus of granular packing rock layers is proportioned to the powers of 1/3 of the vertical contact force of sand particles. The Macroscopic Young’s Modulus is inversely proportional to particle diameter. The paper calculated the vertical contact force of five types aligning mode of the particles. When equal stress, the increased of the coordination number lead to the decrease of the contact force fn, this lead to the coordination number is an inverse proportion to Macroscopic Young’s Modulus. But the larger coordination number change only means very little Macroscopic Young’s Modulus change.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60501019,10775139 and 60971073)
文摘The focusing and the stable transport of an intense elliptic sheet electron beam in a uniform magnetic field are investigated thoroughly by using the macroscopic cold-fluid model and the single-particle orbit theory.The results indicate that the envelopes and the tilted angles of the sheet electron beam obtained by the two theories are consistent.The single-particle orbit theory is more accurate due to its treatment of the space-charge fields in a rectangular drift tube.The macroscopic cold-fluid model describes the collective transport process in order to provide detailed information about the beam dynamics,such as beam shape,density,and velocity profile.The tilt of the elliptic sheet beam in a uniform magnetic field is carefully studied and demonstrated.The results presented in this paper provide two complete theories for systemically discussing the transport of the sheet beam and are useful for understanding and guiding the practical engineering design of electron optics systems in high power vacuum electronic devices.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11164018 and 11074028)the Postdoctoral Science Foundation of China(Grant No. 2011M500808)the Key Project of the Chinese Ministry of Education (Grant No. 212028)
文摘We propose a feasible scheme to generate electromagnetically induced transparency(EIT) and quadripartite macroscopic entanglement in an optomechanical system with one fixed mirror and three movable perfectly reflecting mirrors.We explore the EIT phenomena in this optomechanical system.Results show the appearance of EIT dips in the output field.Moreover,we demonstrate how steady-state quadripartite entanglement can be generated via radiation pressure.We also quantify the bipartite entanglement in each field-mirror subsystem and in the mirror-mirror subsystem.Findings show that a high intensity of entanglement between two subsystems can be achieved.
基金Financial support by the Department of Geology, University of Peshawar
文摘Detailed micro-meso to macroscopic structural analyses reveal two deformation phases in the western limb of the Hazara-Kashmir Syntaxis(HKS). Bulk top to NW shearing transformed initially symmetrical NNE-SSW trending meso to macroscopic folds from asymmetric to overturned ones without changing their trend. Sigmoidal en-echelon tension gashes developed during this deformation,that were oblique to bedding parallel worm burrows and bedding planes themselves. Strain analyses of deformed elliptical ooids using the Rf/Ф method constrain the internal strain patterns of the NNE-SSW structures. The principal stretching axis(S3) defined by deformed elliptical ooids is oriented N27°E at right angles to WNW-ESE shortening. The deformed elliptical ooids in sub-vertical bedding vertical planes contain ooids that plunge -70° SE due to NW-directed tectonic transport. Finite strain ratios are1.45(Rxy) parallel to bedding plane and 1.46(Ryz) for the vertical plane. From these 2D strain values, we derive an oblate strain ellipsoidal in 3D using the Flinn and Hsu/Nadai techniques. Strains calculated from deformed elliptical ooids average-18.10% parallel to bedding and-18.47% in the vertical plane.However, a balanced cross-section through the study area indicates a minimum of--28% shortening.Consequently, regional shortening was only partially accommodated by internal deformation.
基金Supported by the Chinese National Basic Research Project"Nonlinear Science"the National Natural Science Foundation of China under Grant No.49474216the Science Foundation of Shanghai on Traffic Problem Research.
文摘In this paper,a derivation of the macroscopic mean field theory of the cellular automaton(CA)model of highway traffic flow starting from the microscopic dynamical point of view is presented.Starting from an equation describing the time evolution of the Boolean state variable at each site of the basic CA model,and using a two-site approximation for the multi-site correlation functions,a dynamical mapping between the macroscopic average speeds v(t+1)and v(t)at different time can be derived.Mean field results consistent with the simulation data are obtained by considering the attractors of the mapping and their corresponding basins.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11421063 and 11534002)the National Key Basic Research Program of China(Grant No.2014CB921403)+1 种基金the National Key Research and Development Program of China(Grant No.2016YFA0301201)and the NSAF(Grant No.U1530401)
文摘We study how the decoherence of macroscopic objects originates intrinsically from the relativistic effect. With the degree of freedom of the center of mass(CM) characterizing the collective quantum state of a macroscopic object(MO),it is found that an MO consisting of N particles can decohere with a time scale of no more than p (√N)^-1. Here, the special relativity can induce the coupling of the collective motion mode and the relative motion modes in an order of 1/c^2, which intrinsically results in the above minimum decoherence.
基金Project supported by National Creative Research Groups Science Foundation of China(Grant No.60721062)National Basic Research Program of China(Grant No.2007CB714000)
文摘In this paper, we adopt the coarse graining method proposed by Lee H K et al. to develop a macroscopic model from the microscopic traffic model-GOVM. The proposed model inherits the parameter p which considers the influence of next-nearest car introduced in the GOVM model. The simulation results show that the new model is strictly consistent with the former microscopic model. Using this macroscopic model, we can avoid considering the details of each traffic on the road, and build more complex models such as road network model easily in the future.