A new method for solving the tiling problem of surface reconstruction is proposed. The proposed method uses a snake algorithm to segment the original images, the contours are then transformed into strings by Freeman＇...A new method for solving the tiling problem of surface reconstruction is proposed. The proposed method uses a snake algorithm to segment the original images, the contours are then transformed into strings by Freeman＇ s code. Symbolic string matching technique is applied to establish a correspondence between the two consecutive contours. The surface is composed of the pieces reconstructed from the correspondence points. Experimental results show that the proposed method exhibits a good behavior for the quality of surface reconstruction and its time complexity is proportional to mn where m and n are the numbers of vertices of the two consecutive slices, respectively.展开更多
Based on the definition of a logic structure feature to relate logically functional requirements to geometric representation independent upon detailed geometric representation, this paper presents an idea of logical s...Based on the definition of a logic structure feature to relate logically functional requirements to geometric representation independent upon detailed geometric representation, this paper presents an idea of logical structure modeling for computer aided conceptual design and makes attempt to establish a representation formalism of logic structure modeling. The definition and representation of logical structure feature are given and an assembly module definition for supporting top down conceptual design is also proposed. The proposed scheme contributes to several aspects of conceptual design research, especially to provide elementarily a formal methodology for computer aided conceptual design system development and operation.展开更多
An 8 mm-high NiCoCrAlYTa coating was epitaxially built-up on a directionally solidified (DS) Ni-based superalloy blade tip by electro-spark deposition.Epitaxial morphologies of the coating and its microstructural char...An 8 mm-high NiCoCrAlYTa coating was epitaxially built-up on a directionally solidified (DS) Ni-based superalloy blade tip by electro-spark deposition.Epitaxial morphologies of the coating and its microstructural characteristics were investigated by means of SEM,XRD and TEM etc.It is observed that the fine column-like dendrites originated from the γ'-particles or γ'-clusters of the DS substrate and are un-continuously coarsened.The β-phase particles precipitate and grow eutectically with the γ-phase.The orientation of fine column dendrites depends on electro-spark deposition processing parameters and the microstructure can be characterized with superfine γ and β phases.展开更多
Deformation characteristics and constitutive model of seafloor massive sulfide(SMS)were selected as the research object.Uniaxial/triaxial compression test were carried out on the mineral samples,and the deformation ch...Deformation characteristics and constitutive model of seafloor massive sulfide(SMS)were selected as the research object.Uniaxial/triaxial compression test were carried out on the mineral samples,and the deformation characteristics of specimens under various conditions were studied.According to characteristics of the mineral,a new three stages constitutive equation was proposed.The conclusions are as follows:The axial strain,peak strain and maximum strength of seafloor massive sulfide increase with the confining pressure.The elastic modulus of the metal sulfide samples is decreased sharply with the increase of confining pressure.According to characteristics of seafloor massive sulfide,the constitutive equation is divided into three parts,the comparison between theoretical curves and experimental data shows that both of them are in good agreement,which also proves the correctness of the constitutive equation for uniaxial compression.展开更多
Surface morphologies of the films of poly [styrene-b-（ethylene-co-butene）-b-styrene] （SEBS） have been studied by using tapping-mode atomic force microscopy （TM-AFM）. The films of block copolymer were prepared bo...Surface morphologies of the films of poly [styrene-b-（ethylene-co-butene）-b-styrene] （SEBS） have been studied by using tapping-mode atomic force microscopy （TM-AFM）. The films of block copolymer were prepared both by spin-coating on mica and by solvent-casting on different solution surfaces. For spin-coating samples, the effect of solution concentration, solvent, and annealing temperature are investigated. It is shown that changing the concentration of the solution makes no difference on the morphology of the film of the block copolymer. The microstructures are quite stable during thermal annealing; only the size of the domains changes toward the equilibrium configuration. However, solvent annealing can notably change the microstructures. When different selective solvents are used for film spin-coating, different morphologies can be obtained and explained by the different solubility parameters of the solvents. As expected, significant different morphologies in the top and the bottom surfaces of the casting films were observed. The images of the top surfaces reveal cylinder microdomains, while those of the bottom surfaces were spherical morphologies.展开更多
Study of seismic activity in the Kuqa area enables us to infer some possible active faults in basement from the epicentral distribution on different profiles. The relations between active faults in the basement and su...Study of seismic activity in the Kuqa area enables us to infer some possible active faults in basement from the epicentral distribution on different profiles. The relations between active faults in the basement and surface structures are analyzed and the difference between sedimentary cover and basement in their deformation characteristics and the genesis are discussed. The following conclusions have been drawn: (1) the epicentral distribution indicates that, the east Qiulitag and south and north Qiulitag deep faults in the basement correspond to the east and west Qiulitag anticlines, respectively. Moreover, deep faults also exist beneath the Yiqiklik and Yaken anticlines. It indicates that the formation of surface structures is controlled by deep structures; (2) A NE-trending strike-slip fault develops along the line from the western termination of Yiqiklik structure to Dongqiu Well 5 and a NW-trending active fault on the western side of Baicheng. The two active faults across the tectonic strike are the main causes for tectonic segmentation of the Kuqa depression and possibly the cause for the middle segment (Kuqa-Baicheng) of the depression to be more shortened than both its eastern and western terminations; (3) The difference between the sedimentary cover and basement in their deformation characteristics depends mainly on the different properties of media between them. The lithospheric strength of the basement in the basin is fairly high, which determines the basement deformation to be mainly of brittle fracture——seismic activity. While the strength of sedimentary cover is low, where there exist weak thin layers, such as coal and gyps. Under the effect of strong tectonic compression, the sedimentary rocks may undergo strong viscous or plastic flow deformation; meanwhile, an aseismic detachment may take place along the weak layers.展开更多
The research and achievements made on seismic subsidence of loess,obtained over the past30 years,were reviewed.Seismic Subsidence of Loess(SSL)has been verified by microstructure characteristics,dynamic triaxial exper...The research and achievements made on seismic subsidence of loess,obtained over the past30 years,were reviewed.Seismic Subsidence of Loess(SSL)has been verified by microstructure characteristics,dynamic triaxial experiments,and in-situ explosion tests,and has become an important subject in the field of seismic loess engineering research.While,the research is still in the stage of theoretical study of saturated soil,and there are no representative cases of seismic subsidence of loess in historical earthquakes.It is difficult to express structure characteristics using microstructure morphology.While,soil mechanics are available methods for this.Seismic subsidence judgment is absolute in some certain value ranges for several parameters.Therefore,probabilistic judgment should be developed.The seismic subsidence ratio is estimated mostly by empirical formulas or semiempirical and semi-theoretical formulas,which are based on laboratory data.These formulas are not established on the basis of physical process and mechanics of seismic subsidence,and this leads to more variables,complicated computation,and poor practicability.To solve these problems,we need to distinguish the main factors and corresponding variables,to establish a mechanics model for seismic subsidence estimation,and to characterize its physio-mechanical process.The key of anti-seismic subsidence treatment is to reduce the seismic subsidence property of soils,and to lower the interaction between the soil body and underground structures.展开更多
文摘A new method for solving the tiling problem of surface reconstruction is proposed. The proposed method uses a snake algorithm to segment the original images, the contours are then transformed into strings by Freeman＇ s code. Symbolic string matching technique is applied to establish a correspondence between the two consecutive contours. The surface is composed of the pieces reconstructed from the correspondence points. Experimental results show that the proposed method exhibits a good behavior for the quality of surface reconstruction and its time complexity is proportional to mn where m and n are the numbers of vertices of the two consecutive slices, respectively.
文摘Based on the definition of a logic structure feature to relate logically functional requirements to geometric representation independent upon detailed geometric representation, this paper presents an idea of logical structure modeling for computer aided conceptual design and makes attempt to establish a representation formalism of logic structure modeling. The definition and representation of logical structure feature are given and an assembly module definition for supporting top down conceptual design is also proposed. The proposed scheme contributes to several aspects of conceptual design research, especially to provide elementarily a formal methodology for computer aided conceptual design system development and operation.
基金Projects(50671116,50901081) supported by the National Natural Science Foundation of China
文摘An 8 mm-high NiCoCrAlYTa coating was epitaxially built-up on a directionally solidified (DS) Ni-based superalloy blade tip by electro-spark deposition.Epitaxial morphologies of the coating and its microstructural characteristics were investigated by means of SEM,XRD and TEM etc.It is observed that the fine column-like dendrites originated from the γ'-particles or γ'-clusters of the DS substrate and are un-continuously coarsened.The β-phase particles precipitate and grow eutectically with the γ-phase.The orientation of fine column dendrites depends on electro-spark deposition processing parameters and the microstructure can be characterized with superfine γ and β phases.
基金Project(2012AA091291)supported by the National High-tech Research and Development Program of ChinaProject(51074179)supported by the National Natural Science Foundation of ChinaProjects(JCYJ20130401160614378,JCYJ20140506150310437)supported by Shenzhen Science and Technology Innovation Basic Research Foundation,China
文摘Deformation characteristics and constitutive model of seafloor massive sulfide(SMS)were selected as the research object.Uniaxial/triaxial compression test were carried out on the mineral samples,and the deformation characteristics of specimens under various conditions were studied.According to characteristics of the mineral,a new three stages constitutive equation was proposed.The conclusions are as follows:The axial strain,peak strain and maximum strength of seafloor massive sulfide increase with the confining pressure.The elastic modulus of the metal sulfide samples is decreased sharply with the increase of confining pressure.According to characteristics of seafloor massive sulfide,the constitutive equation is divided into three parts,the comparison between theoretical curves and experimental data shows that both of them are in good agreement,which also proves the correctness of the constitutive equation for uniaxial compression.
基金Supported by the National Natural Science Foundation of China (No. 20476025, No. 20236010, No. 20490200) and ShanghaiMunicipal Education Commission of China
文摘Surface morphologies of the films of poly [styrene-b-（ethylene-co-butene）-b-styrene] （SEBS） have been studied by using tapping-mode atomic force microscopy （TM-AFM）. The films of block copolymer were prepared both by spin-coating on mica and by solvent-casting on different solution surfaces. For spin-coating samples, the effect of solution concentration, solvent, and annealing temperature are investigated. It is shown that changing the concentration of the solution makes no difference on the morphology of the film of the block copolymer. The microstructures are quite stable during thermal annealing; only the size of the domains changes toward the equilibrium configuration. However, solvent annealing can notably change the microstructures. When different selective solvents are used for film spin-coating, different morphologies can be obtained and explained by the different solubility parameters of the solvents. As expected, significant different morphologies in the top and the bottom surfaces of the casting films were observed. The images of the top surfaces reveal cylinder microdomains, while those of the bottom surfaces were spherical morphologies.
文摘Study of seismic activity in the Kuqa area enables us to infer some possible active faults in basement from the epicentral distribution on different profiles. The relations between active faults in the basement and surface structures are analyzed and the difference between sedimentary cover and basement in their deformation characteristics and the genesis are discussed. The following conclusions have been drawn: (1) the epicentral distribution indicates that, the east Qiulitag and south and north Qiulitag deep faults in the basement correspond to the east and west Qiulitag anticlines, respectively. Moreover, deep faults also exist beneath the Yiqiklik and Yaken anticlines. It indicates that the formation of surface structures is controlled by deep structures; (2) A NE-trending strike-slip fault develops along the line from the western termination of Yiqiklik structure to Dongqiu Well 5 and a NW-trending active fault on the western side of Baicheng. The two active faults across the tectonic strike are the main causes for tectonic segmentation of the Kuqa depression and possibly the cause for the middle segment (Kuqa-Baicheng) of the depression to be more shortened than both its eastern and western terminations; (3) The difference between the sedimentary cover and basement in their deformation characteristics depends mainly on the different properties of media between them. The lithospheric strength of the basement in the basin is fairly high, which determines the basement deformation to be mainly of brittle fracture——seismic activity. While the strength of sedimentary cover is low, where there exist weak thin layers, such as coal and gyps. Under the effect of strong tectonic compression, the sedimentary rocks may undergo strong viscous or plastic flow deformation; meanwhile, an aseismic detachment may take place along the weak layers.
基金sponsored by the Basic Research Foundation of Institute of Earthquake Science,China Earthquake Administration(No.2011IESLZ03)
文摘The research and achievements made on seismic subsidence of loess,obtained over the past30 years,were reviewed.Seismic Subsidence of Loess(SSL)has been verified by microstructure characteristics,dynamic triaxial experiments,and in-situ explosion tests,and has become an important subject in the field of seismic loess engineering research.While,the research is still in the stage of theoretical study of saturated soil,and there are no representative cases of seismic subsidence of loess in historical earthquakes.It is difficult to express structure characteristics using microstructure morphology.While,soil mechanics are available methods for this.Seismic subsidence judgment is absolute in some certain value ranges for several parameters.Therefore,probabilistic judgment should be developed.The seismic subsidence ratio is estimated mostly by empirical formulas or semiempirical and semi-theoretical formulas,which are based on laboratory data.These formulas are not established on the basis of physical process and mechanics of seismic subsidence,and this leads to more variables,complicated computation,and poor practicability.To solve these problems,we need to distinguish the main factors and corresponding variables,to establish a mechanics model for seismic subsidence estimation,and to characterize its physio-mechanical process.The key of anti-seismic subsidence treatment is to reduce the seismic subsidence property of soils,and to lower the interaction between the soil body and underground structures.
