In this paper, the problem of the synthetic prediction pattern of multiple model systems has been considered. Three synthetic prediction patterns have been presented and some of their properties have been analysed.
This paper demonstrates the channels and methods for location prognosis of concealed ore deposits (bodies) in the deep seated and surrounding districts of productive mines in accordance with their special features. Th...This paper demonstrates the channels and methods for location prognosis of concealed ore deposits (bodies) in the deep seated and surrounding districts of productive mines in accordance with their special features. The system frame map is built, from quick exploration in the field to the rapid building of a model indoors. The main research points of location prognosis are also discussed in the paper, which include: 1) integrating the location with the surrounding geological areas, microscopic with macroscopic; 2) analyzing and synthesizing all geological information of different levels, depths and aspects; 3) laying stress on mineralization series; 4) paying attention to the study of the distribution law of ore bodies; 5) introducing the theory of nonlinear dynamics of ore forming processes to ordinary static prognosis; 6) the necessity of the geophysical me thod in recovering information of concealed ore bodies; 7) the combination of all kinds of geology, geophysics, geochemistry and remote sensing methods.展开更多
Optimization of antenna array pattern used in a spaceborne Synthetic Aperture Radar (SAR) system is considered in this study. A robust evolutionary algorithm, Non-dominated Sorting Genetic Algorithms (the improved NS...Optimization of antenna array pattern used in a spaceborne Synthetic Aperture Radar (SAR) system is considered in this study. A robust evolutionary algorithm, Non-dominated Sorting Genetic Algorithms (the improved NSGA-Ⅱ), is applied on a spaceborne SAR antenna pattern design. The system consists of two objective functions with two constraints. Pareto fronts are generated as a result of multi-objective optimization. After being validated by a test problem ZDT4, the algorithms are used to synthesize spaceborne SAR antenna radiation pattern. The good results with low Ambi- guity-to-Signal Ratio (ASR) and high directivity are obtained in the paper.展开更多
With the shield tunnel going deeper and deeper, the circumferential axial force becomes the governing factor rather than the bending moment. The hand hole acts as a weak point and initial damage in the segment joint e...With the shield tunnel going deeper and deeper, the circumferential axial force becomes the governing factor rather than the bending moment. The hand hole acts as a weak point and initial damage in the segment joint especially when the circumferential axial force is extremely high. Despite the wide application of steel fiber or synthetic fiber in t|ie tunneling, limited researches focus on the structural responses of segment joint with macro structural synthetic fiber (MSSF). In this paper, a 1:2 reduced-scale experiment was conducted to study the structural perfonnance of the segment joint with different types of hand holes under ultra-high axial force. Special attention is paid to failure mode and structural performance (bearing capacity, deformation, cracking, and toughness). Moreover, segment joints with MSSF are also tested to evaluate the effects of MSSF on the failure mode and structural performance of the segment joints. The experiment results show that the hand hole becomes the weakest point of the segment joint under ultra-high axial force. A\/-type crack pattern is always observed before the final failure of the segment joints. Different types and sizes of the hand hole have different degree of influences on the structural behavior of segment joints. The segment joint with MSSF shows higher ultimate bearing capacity and toughness compared to segment joint with common concrete. Besides, the MSSF improves the initial cracking load and anti-spallling resistance of the segment joint.展开更多
Acoustic scattering as the perturbation of an incident acoustic field from an arbitrary object is a critical part of the targetrecognition process in synthetic aperture sonar(SAS)systems.The complexity of scattering m...Acoustic scattering as the perturbation of an incident acoustic field from an arbitrary object is a critical part of the targetrecognition process in synthetic aperture sonar(SAS)systems.The complexity of scattering models strongly depends on the size and structure of the scattered surface.In accurate scattering models including numerical models,the computational cost significantly increases with the object complexity.In this paper,an efficient model is proposed to calculate the acoustic scattering from underwater objects with less computational cost and time compared with numerical models,especially in 3D space.The proposed model,called texture element method(TEM),uses statistical and structural information of the target surface texture by employing non-uniform elements described with local binary pattern(LBP)descriptors by solving the Helmholtz integral equation.The proposed model is compared with two other well-known models,one numerical and other analytical,and the results show excellent agreement between them while the proposed model requires fewer elements.This demonstrates the ability of the proposed model to work with arbitrary targets in different SAS systems with better computational time and cost,enabling the proposed model to be applied in real environment.展开更多
Structural transfer zones in a half-graben rift basin play a significant role in controlling sandy sediments and providing a target for hydrocarbon exploration. Previous studies have classified the transfer zone in la...Structural transfer zones in a half-graben rift basin play a significant role in controlling sandy sediments and providing a target for hydrocarbon exploration. Previous studies have classified the transfer zone in lacustrine environments into two different patterns: synthetic approaching transfer zones and synthetic overlapping transfer zones. However, the evolution of the depositional pattern and the controlling factors of the above transfer zones are still unclear. In the Fushan Sag, the northern South China Sea, an overlapping transfer zone developed in the early Eocene Epoch, while a synthetic approaching transfer zone developed in the late Eocene, due to tectonic uplift. This evolutionary process provided an opportunity to study the stacking pattern of strata architectural variability and facies distribution in the structural transfer zone of the Eocene lacustrine basin. In this study, following the indications of the oriented sedimentary structures in core samples and heavy mineral assemblages of 18 wells, the evolution of the paleo-hydrodynamic distribution during the early and late Eocene has been reconstructed. The sequence-stratigraphy was then divided and the sand body parameters calculated, according to the seismic data and well log interpretations. During the early Eocene, the lake level was at a low stand, the faults broken displacement in the East block being over 50 m. The prograding delta and turbidites are oriented perpendicular to the structural transfer zone. According to the quantitative analysis of the flow rate and the depositional parameters, we speculate that gravity transportation of the sediment and the sediment-supply are the dominating factors during this period. Up to the late Eocene, the rising lake level and the decreased fault displacement leads the flow to divert to a NE-direction, resulting in it being parallel to the axis of the transfer zone. Thus, we speculate that the accommodation space is predominant in this period. In comparison with the above two periods, a braided rive展开更多
文摘In this paper, the problem of the synthetic prediction pattern of multiple model systems has been considered. Three synthetic prediction patterns have been presented and some of their properties have been analysed.
文摘This paper demonstrates the channels and methods for location prognosis of concealed ore deposits (bodies) in the deep seated and surrounding districts of productive mines in accordance with their special features. The system frame map is built, from quick exploration in the field to the rapid building of a model indoors. The main research points of location prognosis are also discussed in the paper, which include: 1) integrating the location with the surrounding geological areas, microscopic with macroscopic; 2) analyzing and synthesizing all geological information of different levels, depths and aspects; 3) laying stress on mineralization series; 4) paying attention to the study of the distribution law of ore bodies; 5) introducing the theory of nonlinear dynamics of ore forming processes to ordinary static prognosis; 6) the necessity of the geophysical me thod in recovering information of concealed ore bodies; 7) the combination of all kinds of geology, geophysics, geochemistry and remote sensing methods.
文摘Optimization of antenna array pattern used in a spaceborne Synthetic Aperture Radar (SAR) system is considered in this study. A robust evolutionary algorithm, Non-dominated Sorting Genetic Algorithms (the improved NSGA-Ⅱ), is applied on a spaceborne SAR antenna pattern design. The system consists of two objective functions with two constraints. Pareto fronts are generated as a result of multi-objective optimization. After being validated by a test problem ZDT4, the algorithms are used to synthesize spaceborne SAR antenna radiation pattern. The good results with low Ambi- guity-to-Signal Ratio (ASR) and high directivity are obtained in the paper.
文摘With the shield tunnel going deeper and deeper, the circumferential axial force becomes the governing factor rather than the bending moment. The hand hole acts as a weak point and initial damage in the segment joint especially when the circumferential axial force is extremely high. Despite the wide application of steel fiber or synthetic fiber in t|ie tunneling, limited researches focus on the structural responses of segment joint with macro structural synthetic fiber (MSSF). In this paper, a 1:2 reduced-scale experiment was conducted to study the structural perfonnance of the segment joint with different types of hand holes under ultra-high axial force. Special attention is paid to failure mode and structural performance (bearing capacity, deformation, cracking, and toughness). Moreover, segment joints with MSSF are also tested to evaluate the effects of MSSF on the failure mode and structural performance of the segment joints. The experiment results show that the hand hole becomes the weakest point of the segment joint under ultra-high axial force. A\/-type crack pattern is always observed before the final failure of the segment joints. Different types and sizes of the hand hole have different degree of influences on the structural behavior of segment joints. The segment joint with MSSF shows higher ultimate bearing capacity and toughness compared to segment joint with common concrete. Besides, the MSSF improves the initial cracking load and anti-spallling resistance of the segment joint.
文摘Acoustic scattering as the perturbation of an incident acoustic field from an arbitrary object is a critical part of the targetrecognition process in synthetic aperture sonar(SAS)systems.The complexity of scattering models strongly depends on the size and structure of the scattered surface.In accurate scattering models including numerical models,the computational cost significantly increases with the object complexity.In this paper,an efficient model is proposed to calculate the acoustic scattering from underwater objects with less computational cost and time compared with numerical models,especially in 3D space.The proposed model,called texture element method(TEM),uses statistical and structural information of the target surface texture by employing non-uniform elements described with local binary pattern(LBP)descriptors by solving the Helmholtz integral equation.The proposed model is compared with two other well-known models,one numerical and other analytical,and the results show excellent agreement between them while the proposed model requires fewer elements.This demonstrates the ability of the proposed model to work with arbitrary targets in different SAS systems with better computational time and cost,enabling the proposed model to be applied in real environment.
基金sponsored by the National Natural Science Foundation of China(No.41572080)the Major State Science and Technology Research Program(No.2016ZX05024002-002)China Scholarship Council(CSC)(No.201906400071)。
文摘Structural transfer zones in a half-graben rift basin play a significant role in controlling sandy sediments and providing a target for hydrocarbon exploration. Previous studies have classified the transfer zone in lacustrine environments into two different patterns: synthetic approaching transfer zones and synthetic overlapping transfer zones. However, the evolution of the depositional pattern and the controlling factors of the above transfer zones are still unclear. In the Fushan Sag, the northern South China Sea, an overlapping transfer zone developed in the early Eocene Epoch, while a synthetic approaching transfer zone developed in the late Eocene, due to tectonic uplift. This evolutionary process provided an opportunity to study the stacking pattern of strata architectural variability and facies distribution in the structural transfer zone of the Eocene lacustrine basin. In this study, following the indications of the oriented sedimentary structures in core samples and heavy mineral assemblages of 18 wells, the evolution of the paleo-hydrodynamic distribution during the early and late Eocene has been reconstructed. The sequence-stratigraphy was then divided and the sand body parameters calculated, according to the seismic data and well log interpretations. During the early Eocene, the lake level was at a low stand, the faults broken displacement in the East block being over 50 m. The prograding delta and turbidites are oriented perpendicular to the structural transfer zone. According to the quantitative analysis of the flow rate and the depositional parameters, we speculate that gravity transportation of the sediment and the sediment-supply are the dominating factors during this period. Up to the late Eocene, the rising lake level and the decreased fault displacement leads the flow to divert to a NE-direction, resulting in it being parallel to the axis of the transfer zone. Thus, we speculate that the accommodation space is predominant in this period. In comparison with the above two periods, a braided rive
基金Supported by the Project of National Science Fund for Distinguished Young Scholars of China under Grant No.60225008(国家杰出青年基金)the National Natural Science Foundation of China under Grant No.60332010(国家自然科学基金)+1 种基金the Project for Young Scientists’ Fund of National Natural Science Foundation of China under Grant No.60303022(国家自然科学基金青年科学基金)the Natural Science Foundation of Beijing of China under Grant No.4052026 (北京市自然科学基金)
