This paper presents an interpolation-based method(IBM)for approximating some trigonometric functions or their integrals as well.It provides two-sided bounds for each function,which also achieves much better approximat...This paper presents an interpolation-based method(IBM)for approximating some trigonometric functions or their integrals as well.It provides two-sided bounds for each function,which also achieves much better approximation effects than those of prevailing methods.In principle,the IBM can be applied for bounding more bounded smooth functions and their integrals as well,and its applications include approximating the integral of sin(x)/x function and improving the famous square root inequalities.展开更多
In the context of digitalization,course resources exhibit multimodal characteristics,covering various forms such as text,images,and videos.Course knowledge and learning resources are becoming increasingly diverse,prov...In the context of digitalization,course resources exhibit multimodal characteristics,covering various forms such as text,images,and videos.Course knowledge and learning resources are becoming increasingly diverse,providing favorable conditions for students’in-depth and efficient learning.Against this backdrop,how to scientifically apply emerging technologies to automatically collect,process,and integrate digital learning resources such as voices,videos,and courseware texts,and better innovate the organization and presentation forms of course knowledge has become an important development direction for“artificial intelligence+education.”This article elaborates on the elements and characteristics of knowledge graphs,analyzes the construction steps of knowledge graphs,and explores the construction methods of multimodal course knowledge graphs from aspects such as dataset collection,course knowledge ontology identification,knowledge discovery,and association,providing references for the intelligent application of online open courses.展开更多
In this paper the authors first present the definition and some properties of weak solutions to 1-D first order linear hyperbolic systems. Then they show that the constructive method with modular structure originally ...In this paper the authors first present the definition and some properties of weak solutions to 1-D first order linear hyperbolic systems. Then they show that the constructive method with modular structure originally given in the framework of classical solutions is still very powerful and effective in the framework of weak solutions to prove the exact boundary(null) controllability and the exact boundary observability for first order hyperbolic systems.展开更多
Performance Management is the core course of human resource management major,but its knowledge points lack multi-dimensional correlations.There are problems such as scattered content and unclear system,and it is urgen...Performance Management is the core course of human resource management major,but its knowledge points lack multi-dimensional correlations.There are problems such as scattered content and unclear system,and it is urgent to reconstruct the content system of the course.Knowledge graph technology can integrate massive and scattered information into an organic structure through semantic correlation and reasoning.The application of knowledge graph to education and teaching can promote scientific and personalized teaching evaluation and better realize individualized teaching.This paper systematically combs the knowledge points of Performance Management course and forms a comprehensive knowledge graph.The knowledge point is associated with specific questions to form the problem map of the course,and then the knowledge point is further associated with the ability target to form the ability map of the course.Then,the knowledge point is associated with teaching materials,question bank and expansion resources to form a systematic teaching database,thereby giving the method of building the content system of Performance Management course based on the knowledge map.This research can be further extended to other core management courses to realize the deep integration of knowledge graph and teaching.展开更多
3D traveltime calculation is widely used in seismic exploration technologies such as seismic migration and tomography. The fast marching method （FMM） is useful for calculating 3D traveltime and has proven to be effi...3D traveltime calculation is widely used in seismic exploration technologies such as seismic migration and tomography. The fast marching method （FMM） is useful for calculating 3D traveltime and has proven to be efficient and stable. However, it has low calculation accuracy near the source, which thus gives it low overall accuracy. This paper proposes a joint traveltime calculation method to solve this problem. The method firstly employs the wavefront construction method （WFC）, which has a higher calculation accuracy than FMM in calculating traveltime in the small area near the source, and secondly adopts FMM to calculate traveltime for the remaining grid nodes. Due to the increase in calculation precision of grid nodes near the source, this new algorithm is shown to have good calculation precision while maintaining the high calculation efficiency of FMM, which is employed in most of the computational area. Results are verified using various numerical models.展开更多
Discrete element model was developed to simulate the ellipsoidal particles moving in the moving bed. Multi-element model was used to describe a ellipsoidal particle, the contact detection algorithm of ellipsoidal part...Discrete element model was developed to simulate the ellipsoidal particles moving in the moving bed. Multi-element model was used to describe a ellipsoidal particle, the contact detection algorithm of ellipsoidal particle was developed, and both contact force and gravity force were considered in the models. The simulation results were validated by our experiment. Three algorithms for representing an ellipsoidal particle were compared in macro and micro aspects. The results show that there exists big difference in the microscopic parameters such as kinetic energy, rotational kinetic energy, deformation, contact force and collision number which leads to the difference of macroscopic parameters. The relative error in the discharge rate and tracer particle position is the largest between 3-tangent-element representation and experimental results. The flow pattern is similar for the 5-element and 3-intersection representations. The only difference is the discharge rate of 5-element representation is larger than the experimental value and that of the 3-intersection representation has the contrary result. Finally the 3-intersection- element reoresentation is chosen in the simulation due to less comouting time than that of the 5-element renresentation.展开更多
The column bioleaching of copper flotation tailings was comparatively investigated using layered heap construction method(LM),agglomerate heap construction method(AM),and pellets-sintering heap construction method(PM)...The column bioleaching of copper flotation tailings was comparatively investigated using layered heap construction method(LM),agglomerate heap construction method(AM),and pellets-sintering heap construction method(PM).The bacterial communities of free,attached,weakly-attached,and strongly-attached microbes in the later bioleaching stage were investigated.In AM group,the addition of lump sulphide ore resulted in the low leachate pH,high ferric iron concentration,and rapid microbial adsorption,which obtained the maximum copper extraction(60.1%)compared with LM(54.6%)and PM(43.9%)groups.The relative abundance of dominant genera and microbial communities of different microbiota underwent changes in three heap construction methods.The alpha-diversity indexes of attached,weakly-attached,and strongly-attached microbes were different,while no significant change was observed in free bacteria.The variation of whole bacterial community was significantly associated with solution pH,total iron,and ferric iron concentrations.Pearson correlation analysis and partial least square path model both indicated that attached bacteria made larger contribution to the copper extraction of tailings.展开更多
According to the requirement of heterogeneous object modeling in additive manufacturing(AM),the Non-Uniform Rational B-Spline(NURBS)method has been applied to the digital representation of heterogeneous object in this...According to the requirement of heterogeneous object modeling in additive manufacturing(AM),the Non-Uniform Rational B-Spline(NURBS)method has been applied to the digital representation of heterogeneous object in this paper.By putting forward the NURBS material data structure and establishing heterogeneous NURBS object model,the accurate mathematical unified representation of analytical and free heterogeneous objects have been realized.With the inverse modeling of heterogeneous NURBS objects,the geometry and material distribution can be better designed to meet the actual needs.Radical Basis Function(RBF)method based on global surface reconstruction and the tensor product surface interpolation method are combined to RBF-NURBS inverse construction method.The geometric and/or material information of regular mesh points is obtained by RBF interpolation of scattered data,and the heterogeneous NURBS surface or object model is obtained by tensor product interpolation.The examples have shown that the heterogeneous objects fitting to scattered data points can be generated effectively by the inverse construction methods in this paper and 3D CAD models for additive manufacturing can be provided.展开更多
A new method for constructing digital-strain-field-image from a moire pattern with the help of digital image processing technique is proposed in this paper. The digital-strain-field-image expresses the strain values d...A new method for constructing digital-strain-field-image from a moire pattern with the help of digital image processing technique is proposed in this paper. The digital-strain-field-image expresses the strain values directly by its grey levels. The digital-strain-field-image can be obtained by making a differentiation for the digital moire pattern and doing a simple division operation. This image not only gives the visual strain field distribution, but also gives the strain values of every point. This method is simple and applicable and has satisfactory accuracy.展开更多
Taking the development of the times as the background,the historical evolution of modern architecture is combed from the perspective of the initial stage of industrialization to post-industrialization and then to the ...Taking the development of the times as the background,the historical evolution of modern architecture is combed from the perspective of the initial stage of industrialization to post-industrialization and then to the information age.It can be seen that there is a close connection between development and modern architecture in the context of the times.With the advancement of science and technology,the construction of buildings has undergone varying degrees of changes due to aesthetics,materials,structure,humanities,and technology.Behind these changes are the results of the progress and development of social productivity.While changing people’s social cognition,it also changes the development process of architecture.展开更多
We investigate strong stability preserving(SSP)implicit-explicit(IMEX)methods for partitioned systems of differential equations with stiff and nonstiff subsystems.Conditions for order p and stage order q=p are derived...We investigate strong stability preserving(SSP)implicit-explicit(IMEX)methods for partitioned systems of differential equations with stiff and nonstiff subsystems.Conditions for order p and stage order q=p are derived,and characterization of SSP IMEX methods is provided following the recent work by Spijker.Stability properties of these methods with respect to the decoupled linear system with a complex parameter,and a coupled linear system with real parameters are also investigated.Examples of methods up to the order p=4 and stage order q—p are provided.Numerical examples on six partitioned test systems confirm that the derived methods achieve the expected order of convergence for large range of stepsizes of integration,and they are also suitable for preserving the accuracy in the stiff limit or preserving the positivity of the numerical solution for large stepsizes.展开更多
In the process of China's modern social development, the demand for electric energy in various industries and people’s daily production and life has increased significantly. However, if we rely solely on thermal ...In the process of China's modern social development, the demand for electric energy in various industries and people’s daily production and life has increased significantly. However, if we rely solely on thermal power generation, it will inevitably cause pollution of the natural environment and substantial waste of fossil resources, which also makes the clean energy of solar power generation and wind power generation widely used. In order to further improve the application level of wind turbines, it is necessary to realize the effective distribution and power transmission through box substations. Based on this, this paper makes an in-depth research and Discussion on the foundation construction method of wind turbine substation, hoping to provide necessary reference for the foundation construction technology and comprehensive level improvement of wind turbine substation in China.展开更多
With the needs of urban development and construction, the contradiction of shortage of land resources has become increasingly prominent. It has become a development trend to strive for building space in the sky and un...With the needs of urban development and construction, the contradiction of shortage of land resources has become increasingly prominent. It has become a development trend to strive for building space in the sky and underground. How to build an underpass tunnel under the condition of numerous interference conditions in urban areas has become a hot issue. Zhengzhou No.107 Auxiliary Road Expressway Project (hereinafter referred to as East Third Ring Road) adopts the form of buried tunnel, with a total length of 2756.6m, a width of about 39m, and a maximum excavation depth of 15m. It is located on the east side of Zhengzhou East Railway Station, and the tunnel crosses Zhengzhou Metro Line 1. The tunnel structure crosses the subway, with a minimum vertical clearance of 5.08m and a horizontal displacement and radial convergence of less than 6mm. Therefore, it is necessary to ensure the construction safety of Metro Line 1 without stopping.展开更多
The wide application of new technologies, new processes and new materials puts forward higher requirements for the construction quality of water conservancy projects in the new era. The construction quality of asphalt...The wide application of new technologies, new processes and new materials puts forward higher requirements for the construction quality of water conservancy projects in the new era. The construction quality of asphalt concrete core wall is easy to be affected by various factors. In order to ensure the engineering quality, full experiments should be carried out. The paving thickness, layers and other parameters of rolled asphalt concrete core wall should meet the technical requirements and provide a solid guarantee for the engineering quality.展开更多
The first permanent magnet driven rectangular pipe jacking machine independently developed in China is used for the construction of pedestrian passage in Banxuegang Science and Technology City area of Shenzhen. The re...The first permanent magnet driven rectangular pipe jacking machine independently developed in China is used for the construction of pedestrian passage in Banxuegang Science and Technology City area of Shenzhen. The rectangular pipe jacking machine occupies a small area during the initial excavation. It is suitable for shallow soil covering and short-distance excavation. It is more economical and applicable than shield machine and has high construction efficiency. During the construction process, technical measures such as attitude measurement and adjustment of pipe jacking machine, surrounding rock grouting and friction reduction can effectively ensure the smooth construction of pipe jacking machine, and provide reference for large section pipe jacking machine in shallow soil construction.展开更多
The concept of labor division and multi-module cooperation of microbial consortia offers it promising potentials in various areas,such as the utilization of complex substrates,synthesis of natural compounds with long ...The concept of labor division and multi-module cooperation of microbial consortia offers it promising potentials in various areas,such as the utilization of complex substrates,synthesis of natural compounds with long metabolic pathways and remediation of environmental pollutants within a hostile environment.Consequently,synthetic microbial consortia represent a new frontier for synthetic biology because they can solve more complex problems than monocultures.However,current research on microbial consortia often involves the simple mixing of multiphase systems,where strains are co-cultured sequentially or individually cultured and then mixed-cultured.The instability and low efficiency of microbial consortia systems hindered their practical application.To construct a stable and efficient microbial consortium,it is essential to consider the different growth and metabolic characteristics of strains,the competition for various nutrients as well as the complex carbon,energy and signaling dynamics within the system.In this review,we provide a progressive strategy for constructing a stable and efficient microbial consortium system across three stages:compromised stage(work together),microenvironment-oriented stage(work better),and metabolite delivery-enhanced stage(work best).The detailed methods and points for attention of each stage are summarized,with a highlight on the technical bottleneck and application limitations.Through the integration of interdisciplinary strategies,such as materials science and mathematical models,the goal of building a stable and efficient microbial consortium is constantly advanced.展开更多
It has been a focus of debate for a large time on construction methods for large-span loess tunnel.Reasonable construction method has much effect on stability of tunnel and construction schedule.Deformation and failur...It has been a focus of debate for a large time on construction methods for large-span loess tunnel.Reasonable construction method has much effect on stability of tunnel and construction schedule.Deformation and failure of surrounding rock are quite complex.Associating with the large-span loess tunnel of Zhengzhou- Xi'an high-speed passenger rail line in China,large scale model test with geometric proportion 1:20 is applied to study on dynamic mechanical behavior of various construction methods.They include full-face excavation with support and no support,and benching method with support.It is found that pre-deformation and stress accumulation take place ahead of working face.The effects of three construction methods are further studied,particularly in terms of tunnel displacement and stress changes.It is revealed that benching method transfers load to an unexcavated area,limits horizontal deformation,reduces stress concentration effectively,lengthens the distance between location of peak for stress concentration and working face,and consequently increases stability.The model test results not only supply theoretical foundation for determination of reasonable construction method,but also can act as reference for similar tunnel and underground engineering construction.展开更多
According to site-specific environments such as high water pressures, high in-situ stresses and strong rockbursts, the design scheme of the long and deep diversion tunnels at Jinping II hydropower station was optimize...According to site-specific environments such as high water pressures, high in-situ stresses and strong rockbursts, the design scheme of the long and deep diversion tunnels at Jinping II hydropower station was optimized to ensure construction safety. New drainage tunnels were considered. Furthermore, lining structures and grouting pressures were modified during the excavation of tunnels. The construction scheme was updated dynamically based on the complex geological conditions. For instances, the diversion tunnels were first excavated by drilling and blasting method at the first stage of construction, and then by the combination method of tunnel boring machine （TBM） and drilling and blasting, and finally by drilling and blasting method. Through optimized scheme and updated construction scheme, the excavation of diversion tunnel #1 was successfully completed in June, 2011. This paper summarizes the key issues in rock mechanics associated with the construction of the long and deep diversion tunnels at Jinping II hydropower station. The experiences of design and construction obtained from this project could provide reference to similar projects.展开更多
This paper is concerned with the generalized nonlinear second-order equation.By the direct construction method,all of the first-order multipliers of the equation are obtained,and the corresponding complete conservatio...This paper is concerned with the generalized nonlinear second-order equation.By the direct construction method,all of the first-order multipliers of the equation are obtained,and the corresponding complete conservation laws(CLs) of such equations are provided.Furthermore,the integrability of the equation is considered in terms of the conservation laws.In addition,the relationship of multipliers and symmetries of the equations is investigated.展开更多
基金Supported by the National Natural Science Foundation of China(61672009,61502130).
文摘This paper presents an interpolation-based method(IBM)for approximating some trigonometric functions or their integrals as well.It provides two-sided bounds for each function,which also achieves much better approximation effects than those of prevailing methods.In principle,the IBM can be applied for bounding more bounded smooth functions and their integrals as well,and its applications include approximating the integral of sin(x)/x function and improving the famous square root inequalities.
基金University-level Scientific Research Project in Natural Sciences“Research on the Retrieval Method of Multimodal First-Class Course Teaching Content Based on Knowledge Graph Collaboration”(GKY-2024KYYBK-31)。
文摘In the context of digitalization,course resources exhibit multimodal characteristics,covering various forms such as text,images,and videos.Course knowledge and learning resources are becoming increasingly diverse,providing favorable conditions for students’in-depth and efficient learning.Against this backdrop,how to scientifically apply emerging technologies to automatically collect,process,and integrate digital learning resources such as voices,videos,and courseware texts,and better innovate the organization and presentation forms of course knowledge has become an important development direction for“artificial intelligence+education.”This article elaborates on the elements and characteristics of knowledge graphs,analyzes the construction steps of knowledge graphs,and explores the construction methods of multimodal course knowledge graphs from aspects such as dataset collection,course knowledge ontology identification,knowledge discovery,and association,providing references for the intelligent application of online open courses.
基金supported by the National Natural Science Foundation of China(Nos.11831011,11901082)the Natural Science Foundation of Jiangsu Province(No.BK20190323)the Fundamental Research Funds for the Central Universities of China。
文摘In this paper the authors first present the definition and some properties of weak solutions to 1-D first order linear hyperbolic systems. Then they show that the constructive method with modular structure originally given in the framework of classical solutions is still very powerful and effective in the framework of weak solutions to prove the exact boundary(null) controllability and the exact boundary observability for first order hyperbolic systems.
基金Education and Teaching Reform Research Project of Chongqing Institute of Engineering(JY2023206)。
文摘Performance Management is the core course of human resource management major,but its knowledge points lack multi-dimensional correlations.There are problems such as scattered content and unclear system,and it is urgent to reconstruct the content system of the course.Knowledge graph technology can integrate massive and scattered information into an organic structure through semantic correlation and reasoning.The application of knowledge graph to education and teaching can promote scientific and personalized teaching evaluation and better realize individualized teaching.This paper systematically combs the knowledge points of Performance Management course and forms a comprehensive knowledge graph.The knowledge point is associated with specific questions to form the problem map of the course,and then the knowledge point is further associated with the ability target to form the ability map of the course.Then,the knowledge point is associated with teaching materials,question bank and expansion resources to form a systematic teaching database,thereby giving the method of building the content system of Performance Management course based on the knowledge map.This research can be further extended to other core management courses to realize the deep integration of knowledge graph and teaching.
基金supported by NSFC(Nos.41274120,41404085,and 41504084)
文摘3D traveltime calculation is widely used in seismic exploration technologies such as seismic migration and tomography. The fast marching method （FMM） is useful for calculating 3D traveltime and has proven to be efficient and stable. However, it has low calculation accuracy near the source, which thus gives it low overall accuracy. This paper proposes a joint traveltime calculation method to solve this problem. The method firstly employs the wavefront construction method （WFC）, which has a higher calculation accuracy than FMM in calculating traveltime in the small area near the source, and secondly adopts FMM to calculate traveltime for the remaining grid nodes. Due to the increase in calculation precision of grid nodes near the source, this new algorithm is shown to have good calculation precision while maintaining the high calculation efficiency of FMM, which is employed in most of the computational area. Results are verified using various numerical models.
基金Supported by the Major State Basic Research Development Program of China （2011CB201505）, the National Natural Science Foundation of China （50976025） and the Key Proj ect.of Science and Technology of Henan Province （12B610012）.
文摘Discrete element model was developed to simulate the ellipsoidal particles moving in the moving bed. Multi-element model was used to describe a ellipsoidal particle, the contact detection algorithm of ellipsoidal particle was developed, and both contact force and gravity force were considered in the models. The simulation results were validated by our experiment. Three algorithms for representing an ellipsoidal particle were compared in macro and micro aspects. The results show that there exists big difference in the microscopic parameters such as kinetic energy, rotational kinetic energy, deformation, contact force and collision number which leads to the difference of macroscopic parameters. The relative error in the discharge rate and tracer particle position is the largest between 3-tangent-element representation and experimental results. The flow pattern is similar for the 5-element and 3-intersection representations. The only difference is the discharge rate of 5-element representation is larger than the experimental value and that of the 3-intersection representation has the contrary result. Finally the 3-intersection- element reoresentation is chosen in the simulation due to less comouting time than that of the 5-element renresentation.
基金financial supports from the National Key R&D Program of China(No.2018YFC1801804)the Shandong Provincial Natural Science Foundation,China(Nos.ZR2020QD120 and ZR2018LD001)Project of Introducing and Cultivating Young Talent in the Universities of Shandong Province,China(No.QC2019YY144)。
文摘The column bioleaching of copper flotation tailings was comparatively investigated using layered heap construction method(LM),agglomerate heap construction method(AM),and pellets-sintering heap construction method(PM).The bacterial communities of free,attached,weakly-attached,and strongly-attached microbes in the later bioleaching stage were investigated.In AM group,the addition of lump sulphide ore resulted in the low leachate pH,high ferric iron concentration,and rapid microbial adsorption,which obtained the maximum copper extraction(60.1%)compared with LM(54.6%)and PM(43.9%)groups.The relative abundance of dominant genera and microbial communities of different microbiota underwent changes in three heap construction methods.The alpha-diversity indexes of attached,weakly-attached,and strongly-attached microbes were different,while no significant change was observed in free bacteria.The variation of whole bacterial community was significantly associated with solution pH,total iron,and ferric iron concentrations.Pearson correlation analysis and partial least square path model both indicated that attached bacteria made larger contribution to the copper extraction of tailings.
文摘According to the requirement of heterogeneous object modeling in additive manufacturing(AM),the Non-Uniform Rational B-Spline(NURBS)method has been applied to the digital representation of heterogeneous object in this paper.By putting forward the NURBS material data structure and establishing heterogeneous NURBS object model,the accurate mathematical unified representation of analytical and free heterogeneous objects have been realized.With the inverse modeling of heterogeneous NURBS objects,the geometry and material distribution can be better designed to meet the actual needs.Radical Basis Function(RBF)method based on global surface reconstruction and the tensor product surface interpolation method are combined to RBF-NURBS inverse construction method.The geometric and/or material information of regular mesh points is obtained by RBF interpolation of scattered data,and the heterogeneous NURBS surface or object model is obtained by tensor product interpolation.The examples have shown that the heterogeneous objects fitting to scattered data points can be generated effectively by the inverse construction methods in this paper and 3D CAD models for additive manufacturing can be provided.
文摘A new method for constructing digital-strain-field-image from a moire pattern with the help of digital image processing technique is proposed in this paper. The digital-strain-field-image expresses the strain values directly by its grey levels. The digital-strain-field-image can be obtained by making a differentiation for the digital moire pattern and doing a simple division operation. This image not only gives the visual strain field distribution, but also gives the strain values of every point. This method is simple and applicable and has satisfactory accuracy.
基金Sponsored by Hebei Postgraduate Demonstration Curriculum Construction Project(KCJSX2020081)。
文摘Taking the development of the times as the background,the historical evolution of modern architecture is combed from the perspective of the initial stage of industrialization to post-industrialization and then to the information age.It can be seen that there is a close connection between development and modern architecture in the context of the times.With the advancement of science and technology,the construction of buildings has undergone varying degrees of changes due to aesthetics,materials,structure,humanities,and technology.Behind these changes are the results of the progress and development of social productivity.While changing people’s social cognition,it also changes the development process of architecture.
文摘We investigate strong stability preserving(SSP)implicit-explicit(IMEX)methods for partitioned systems of differential equations with stiff and nonstiff subsystems.Conditions for order p and stage order q=p are derived,and characterization of SSP IMEX methods is provided following the recent work by Spijker.Stability properties of these methods with respect to the decoupled linear system with a complex parameter,and a coupled linear system with real parameters are also investigated.Examples of methods up to the order p=4 and stage order q—p are provided.Numerical examples on six partitioned test systems confirm that the derived methods achieve the expected order of convergence for large range of stepsizes of integration,and they are also suitable for preserving the accuracy in the stiff limit or preserving the positivity of the numerical solution for large stepsizes.
文摘In the process of China's modern social development, the demand for electric energy in various industries and people’s daily production and life has increased significantly. However, if we rely solely on thermal power generation, it will inevitably cause pollution of the natural environment and substantial waste of fossil resources, which also makes the clean energy of solar power generation and wind power generation widely used. In order to further improve the application level of wind turbines, it is necessary to realize the effective distribution and power transmission through box substations. Based on this, this paper makes an in-depth research and Discussion on the foundation construction method of wind turbine substation, hoping to provide necessary reference for the foundation construction technology and comprehensive level improvement of wind turbine substation in China.
文摘With the needs of urban development and construction, the contradiction of shortage of land resources has become increasingly prominent. It has become a development trend to strive for building space in the sky and underground. How to build an underpass tunnel under the condition of numerous interference conditions in urban areas has become a hot issue. Zhengzhou No.107 Auxiliary Road Expressway Project (hereinafter referred to as East Third Ring Road) adopts the form of buried tunnel, with a total length of 2756.6m, a width of about 39m, and a maximum excavation depth of 15m. It is located on the east side of Zhengzhou East Railway Station, and the tunnel crosses Zhengzhou Metro Line 1. The tunnel structure crosses the subway, with a minimum vertical clearance of 5.08m and a horizontal displacement and radial convergence of less than 6mm. Therefore, it is necessary to ensure the construction safety of Metro Line 1 without stopping.
文摘The wide application of new technologies, new processes and new materials puts forward higher requirements for the construction quality of water conservancy projects in the new era. The construction quality of asphalt concrete core wall is easy to be affected by various factors. In order to ensure the engineering quality, full experiments should be carried out. The paving thickness, layers and other parameters of rolled asphalt concrete core wall should meet the technical requirements and provide a solid guarantee for the engineering quality.
文摘The first permanent magnet driven rectangular pipe jacking machine independently developed in China is used for the construction of pedestrian passage in Banxuegang Science and Technology City area of Shenzhen. The rectangular pipe jacking machine occupies a small area during the initial excavation. It is suitable for shallow soil covering and short-distance excavation. It is more economical and applicable than shield machine and has high construction efficiency. During the construction process, technical measures such as attitude measurement and adjustment of pipe jacking machine, surrounding rock grouting and friction reduction can effectively ensure the smooth construction of pipe jacking machine, and provide reference for large section pipe jacking machine in shallow soil construction.
基金supported by the National Key Research and Development Program of China(2022YFC2104800)the Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture(XTD2205)the State Key Laboratory of Materials-Oriented Chemical Engineering(KL-MCE-23A10).
文摘The concept of labor division and multi-module cooperation of microbial consortia offers it promising potentials in various areas,such as the utilization of complex substrates,synthesis of natural compounds with long metabolic pathways and remediation of environmental pollutants within a hostile environment.Consequently,synthetic microbial consortia represent a new frontier for synthetic biology because they can solve more complex problems than monocultures.However,current research on microbial consortia often involves the simple mixing of multiphase systems,where strains are co-cultured sequentially or individually cultured and then mixed-cultured.The instability and low efficiency of microbial consortia systems hindered their practical application.To construct a stable and efficient microbial consortium,it is essential to consider the different growth and metabolic characteristics of strains,the competition for various nutrients as well as the complex carbon,energy and signaling dynamics within the system.In this review,we provide a progressive strategy for constructing a stable and efficient microbial consortium system across three stages:compromised stage(work together),microenvironment-oriented stage(work better),and metabolite delivery-enhanced stage(work best).The detailed methods and points for attention of each stage are summarized,with a highlight on the technical bottleneck and application limitations.Through the integration of interdisciplinary strategies,such as materials science and mathematical models,the goal of building a stable and efficient microbial consortium is constantly advanced.
基金the National Natural Science Foundation of China(Nos. 50978172 and 51078318)the New Century Excellent Talents in University(No. 10-0667)
文摘It has been a focus of debate for a large time on construction methods for large-span loess tunnel.Reasonable construction method has much effect on stability of tunnel and construction schedule.Deformation and failure of surrounding rock are quite complex.Associating with the large-span loess tunnel of Zhengzhou- Xi'an high-speed passenger rail line in China,large scale model test with geometric proportion 1:20 is applied to study on dynamic mechanical behavior of various construction methods.They include full-face excavation with support and no support,and benching method with support.It is found that pre-deformation and stress accumulation take place ahead of working face.The effects of three construction methods are further studied,particularly in terms of tunnel displacement and stress changes.It is revealed that benching method transfers load to an unexcavated area,limits horizontal deformation,reduces stress concentration effectively,lengthens the distance between location of peak for stress concentration and working face,and consequently increases stability.The model test results not only supply theoretical foundation for determination of reasonable construction method,but also can act as reference for similar tunnel and underground engineering construction.
文摘According to site-specific environments such as high water pressures, high in-situ stresses and strong rockbursts, the design scheme of the long and deep diversion tunnels at Jinping II hydropower station was optimized to ensure construction safety. New drainage tunnels were considered. Furthermore, lining structures and grouting pressures were modified during the excavation of tunnels. The construction scheme was updated dynamically based on the complex geological conditions. For instances, the diversion tunnels were first excavated by drilling and blasting method at the first stage of construction, and then by the combination method of tunnel boring machine （TBM） and drilling and blasting, and finally by drilling and blasting method. Through optimized scheme and updated construction scheme, the excavation of diversion tunnel #1 was successfully completed in June, 2011. This paper summarizes the key issues in rock mechanics associated with the construction of the long and deep diversion tunnels at Jinping II hydropower station. The experiences of design and construction obtained from this project could provide reference to similar projects.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11171041 and 10971018the Natural Science Foundation of Shandong Province under Grant No.ZR2010AM029+1 种基金the Promotive Research Fund for Young and Middle-Aged Scientists of Shandong Province under Grant No.BS2010SF001 the Doctoral Foundation of Binzhou University under Grant No.2009Y01
文摘This paper is concerned with the generalized nonlinear second-order equation.By the direct construction method,all of the first-order multipliers of the equation are obtained,and the corresponding complete conservation laws(CLs) of such equations are provided.Furthermore,the integrability of the equation is considered in terms of the conservation laws.In addition,the relationship of multipliers and symmetries of the equations is investigated.
