Sperber ＆ Wilson point out the cognitive nature of context when they explicate relevance theory. Cognitive context exerts its function dynamically. The process of communication is the participation of cognitive conte...Sperber ＆ Wilson point out the cognitive nature of context when they explicate relevance theory. Cognitive context exerts its function dynamically. The process of communication is the participation of cognitive context. Without cognitive context, the verbal communication can not be realized.展开更多
How to make college English teaching （CET） tailed to the requirement of the society is a topic of great significance. This paper is meant to give a description of CET from a new aspect——dynamic context. By giving ...How to make college English teaching （CET） tailed to the requirement of the society is a topic of great significance. This paper is meant to give a description of CET from a new aspect——dynamic context. By giving an analysis of the current situation of CET in China as well as the introduction of the theory of DC, this paper attempts to give a description of CET in dynamic contexts （DC） to improve the students＇ communicative competence to meet the need of the society.展开更多
This numerical study of the Bohai Sea wintertime circulation by means of a two dimensional barotropic model with resolution of 1/24° in longitude and latitude showed that the Bohai Sea wintertime circulation is d...This numerical study of the Bohai Sea wintertime circulation by means of a two dimensional barotropic model with resolution of 1/24° in longitude and latitude showed that the Bohai Sea wintertime circulation is dominated by local monsoon winds. The major current components include the Bohai Warm Current, the North Shandong Coastal Current, and the Liaodong Gyre. The Bohai Warm Current originates from the Yellow Sea Warm Current at the northern part of Bohai Strait, meanders westwards and finally enters the northern part of Bohai Bay. The North Shandong Coastal Current flows along the southwest shore of Bohai Bay and Laizhou Bay and exits from the Bohai Sea through the south Bohai Strait. The anticyclonic Liaodong Gyre is located in the north of Liaodong Bay. A pair of eddies and the small scale Jinzhou Gyre are found between the Bohai Warm Current and the Liaodong Gyre. The computed volume transport for both the Bohai Warm Current and North Shandong Coastal Current is about 0.03 Sv (1 Sv=1×10 6 m 3/s). The numerical experiments showed that the combined effect of local monsoon winds and bottom topography dominate the formation of the circulation pattern. The Coriolis force and the wind stress curl are of certain importance. The beta effect, the momentum advection and the open boundary condition have little influence on the circulation pattern.展开更多
Verschueren's Theory of Adaptation argues that the process of using language is the result of the language users consciously make continuous linguistic choices and adapt to the contexts, consciously or unconscious...Verschueren's Theory of Adaptation argues that the process of using language is the result of the language users consciously make continuous linguistic choices and adapt to the contexts, consciously or unconsciously, for language-internal and/or language-external reasons. The contextual adaptation well explains the characteristics of dynamic contextual development in diplomatic escort interpreting. It is helpful for interpreters to understand that the choice-making was constrained by different contexts in diplomatic interpreting. In addition, interpreters should adapt to the various factors of the context thus can make flexible and appropriate choices in delivering target language in order to promote the quality of interpretation and achieve the satisfactory communicative effect.展开更多
Requirements of software systems tend to change over time. The speed of this tendency depends on the application domain the software system under consideration belongs to. If we consider novel contexts such as pervasi...Requirements of software systems tend to change over time. The speed of this tendency depends on the application domain the software system under consideration belongs to. If we consider novel contexts such as pervasive systems and systems supporting dynamic B2B interaction, requirements change so fast that the research community is studying how to build systems that are able to self-adapt on the fly to some of these changes. When this happens, the system does not need to undergo through a new development cycle thus increasing its availability and, to a certain extent, its robustness. So far, the research in the area of self-adaptive systems has been focusing on the definition of the mechanisms for supporting self-adaptation. We argue that what is missing now is a structured and robust design process associated to these mechanisms. This design process should include a Requirement Engineering (RE) phase that somewhat differs from the traditional one. However, the identification of requirements for adaptation requires a good knowledge of the context in which the system will be executed. In this work, we consider the modeling of such context as part of the RE phase and we particularly focus on Service-Based Applications (SBAs). We argue that RE activities should be supported at run-time to handle context changes and to support adaptation for SBAs. We survey the state of the art for what concerns the elicitation, modeling, and analysis of requirements and will highlight some issues and challenges in order to support adaptation for SBAs.展开更多
Taken discourse production as the research objective,it holds that discourse production is dynamic in human communication.It attempts to analyze the dynamics on the basis of Relevance-adaption model from the perspecti...Taken discourse production as the research objective,it holds that discourse production is dynamic in human communication.It attempts to analyze the dynamics on the basis of Relevance-adaption model from the perspective of cognitive pragmatics and explain the role of the context dynamics that plays in the discourse production.展开更多
This paper deals with reduction of losses in electric power distribution system through a dynamic reconfiguration case study of a grid in the city of Mostar,Bosnia and Herzegovina.The proposed solution is based on a n...This paper deals with reduction of losses in electric power distribution system through a dynamic reconfiguration case study of a grid in the city of Mostar,Bosnia and Herzegovina.The proposed solution is based on a nonlinear model predictive control algorithm which determines the optimal switching operations of the distribution system.The goal of the control algorithm is to find the optimal radial network topology which minimizes cumulative active power losses and maximizes voltages across the network while simultaneously satisfying all system constraints.The optimization results are validated through multiple simulations(using real power demand data collected for a few characteristic days during winter and summer)which demonstrate the efficiency and usefulness of the developed control algorithm in reducing the grid losses by up to 14%.展开更多
Definition of termsInputs can be defined as everything which students bring tothe classroom including their prior teaching and learningenvironment,attitude,enthusiasm,motivation,phonologyfrom their first language and ...Definition of termsInputs can be defined as everything which students bring tothe classroom including their prior teaching and learningenvironment,attitude,enthusiasm,motivation,phonologyfrom their first language and varying degrees of confidence.When they arrive in college they are exposed to spoken Englishfrom a range of teachers who have a variety of spoken abilitiesand teaching techniques.展开更多
Becoming a mother is one of the most monumental experiences in a woman's lifetime. Women typically bear the primary caregiving responsibility for their infants, and they undergo numerous changes both mentally and ...Becoming a mother is one of the most monumental experiences in a woman's lifetime. Women typically bear the primary caregiving responsibility for their infants, and they undergo numerous changes both mentally and physically, including behavioral, emotional, and hormonal changes, during the postpartum period. Studies have indicated that hormonal, experiential, and temporal factors significantly regulate emotional and cognitive brain functions during the postpartum period [1]. The determination of the neural basis of a maternal brain is critically important for understanding mother-infant attachments and thus perpetuating the human species. Until recently, limited investigations of the neuroanatomical and functional status of mothers have contributed to understanding the processing of maternal behaviors.展开更多
A new meso-mechanical testing scheme based on SEM was developed to carry out the experiment of microfracturing process of rocks. The microfracturing process of the pre-crack marble sample on surrounding rock in the im...A new meso-mechanical testing scheme based on SEM was developed to carry out the experiment of microfracturing process of rocks. The microfracturing process of the pre-crack marble sample on surrounding rock in the immerged Long-big tunnel in Jinping Cascade II Hydropower Station under uniaxial compression was recorded by using the testing scheme. According to the stereology theory, the propagation and coalescent of cracks at meso-scale were quantitatively investigated with digital technology. Therefore, the basic geometric information of rock microcracks such as area, angle, length, width, perimeter, was obtained from binary images after segmentation. The failure mechanism of specimen under uniaxial compression with the quantitative information was studied from macro and microscopic point of view. The results show that the image of microfracturing process of the specimen can be observed and recorded digitally. During the damage of the specimen, the distribution of microcracks in the specimen is still subjected to exponential distribution with some microcracks concentrated in certain regions. Finally, the change law of the fractal dimension of the local element in marble sample under different external load conditions is obtained by means of the statistical calculation of the fractal dimension.展开更多
An experimental apparatus composed of microscope, video camera. image-processing, and mini reactor which can be used for real-time measurement of the growth of polymer particle in gas phase polymerization was built up...An experimental apparatus composed of microscope, video camera. image-processing, and mini reactor which can be used for real-time measurement of the growth of polymer particle in gas phase polymerization was built up to carry out dynamic study of gas phase polymerization of butadiene by heterogeneous catalyst based on neodymium(Nd). The studies of the shape duplication of polymer particles and catalyst particles and the growth rate of polymer particle were made. Results show that the apparatus and procedure designed can be well utilized to make dynamic observation and data collection of the growth of polymer particle in gas phase polymerization. A phenomenon of shape duplication of polymer particles and catalyst particles was observed by the real-time measurement. The result also concludes that the activity of individual catalyst particle is different, and the effect of reaction pressure on the growth of polymer particle is significant.展开更多
Mechanical properties of high-entropy alloys(HEAs)with the face-centered cubic(fcc)structure strongly depend on their initial grain orientations.However,the orientation-dependent mechanical responses and the underlyin...Mechanical properties of high-entropy alloys(HEAs)with the face-centered cubic(fcc)structure strongly depend on their initial grain orientations.However,the orientation-dependent mechanical responses and the underlying plastic fl ow mechanisms of such alloys are not yet well understood.Here,deformation of the equiatomic FeMnCoCrNi HEA with various initial orientations under uniaxial tensile testing has been studied by using atomistic simulations,showing the results consistent with the recent experiments on fcc HEAs.The quantitative analysis of the activated deformation modes shows that the initiation of stacking faults is the main plastic deformation mechanism for the crystals initially oriented with[001],[111],and[112],and the total dislocation densities in these crystals are higher than that with the[110]and[123]orientations.Stacking faults,twinning,and hcp-martensitic transformation jointly promote the plastic deformation of the[110]orientation,and twinning in this crystal is more significant than that with other orientations.Deformation in the crystal oriented with[123]is dominated by the hcp-martensite transformation.Comparison of the mechanical behaviors in the FeMnCoCrNi alloy and the conventional materials,i.e.Cu and Fe50Ni50,has shown that dislocation slip tends to be activated more readily in the HEA.This is attributed to the larger lattice distortion in the HEA than the low-entropy materials,leading to the lower critical stress for dislocation nucleation and elastic–plastic transition in the former.In addition,the FeMnCoCrNi HEA with the larger lattice distortion leads to an enhanced capacity of storing dislocations.However,for the[001]-oriented HEA in which dislocation slip and stacking fault are the dominant deformation mechanisms,the limited deformation modes activated are insu fficient to improve the work hardening ability of the material.展开更多
FITC-conjugated nanoferrofluid (FNFF) was synthesized and characterized to study the dynamic of laser-induced transport of NPs in water. The results confirmed a definite laser-induced enhanced velocity of NPs (100 &am...FITC-conjugated nanoferrofluid (FNFF) was synthesized and characterized to study the dynamic of laser-induced transport of NPs in water. The results confirmed a definite laser-induced enhanced velocity of NPs (100 μm⋅s−1) almost twice as much the without laser (i.e. Brownian motion). The diffusion coefficients of 17 × 10−6 m2⋅s−1 and 55 × 10−6 m2⋅s−1 were found for the cases without and with laser action respectively. The act of laser when switched on after NPs had reached the steady state was very prominent. The laser-induced heat and power generated by NPs were calculated 0.2μW⋅cm−3 and 0.4 pW⋅cm−2 respectively. Our experiment condition was non-adiabatic and that the heat generated was diffused into the surrounding. We considered the Maxwell’s criteria (Kp/Kw −1⋅K−1. Based on the Brownian diffusion and DLVO theory, at earlier times where the NPs are more dispersed within the medium are displaced faster. However, at later stages they become less mobile as they are agglomerated. The mechanisms for the enhanced mobility and laser transport of NPs are thought to be due to e.m.w induced force (i.e. an oscillatory motion) and laser absorptive force (i.e., photothermophoresis). A beam divergence of about 5.24°(or 91 mrad) was determined. A non-linear behaviour of laser beam was observed as a trajectory path within the water due to thermal heating hence causing the change of refractive index of medium and redistribution of NPs concentration.展开更多
A numerical investigation is conducted to explore the evolution of a plasma discharge and its interaction with the fluid flow based on a self-consistent fluid model which couples the discharge dynamics with the fluid ...A numerical investigation is conducted to explore the evolution of a plasma discharge and its interaction with the fluid flow based on a self-consistent fluid model which couples the discharge dynamics with the fluid dynamics.The effects of the applied voltage on the distribution of velocity and temperature in initially static air are parainetrically studied.Furthermore,the spatial structure of plasma discharge and the resulting force contours in streamwise and normal directions are discussed in detail.The result shows that the plasma actuator produces a net force that should always be directed away from the exposed electrode,which results in an ionic wind pushing particles into a jet downstream of the actuator.When the energy added by the plasma is taken into account,the ambient air temperature is increased slightly around the electrode,but the velocity is almost not affected.Therefore it is unlikely that the induced flow is buoyancy driven.For the operating voltages considered in this paper,the maximum induced velocity is found to follow a power law,i.e.,it is proportional to the applied voltage to the 3.5 power.This promises an efficient application in the flow control with plasma actuators.展开更多
In the context of power generation companies, vast amounts of specialized data and expert knowledge have been accumulated. However, challenges such as data silos and fragmented knowledge hinder the effective utilizati...In the context of power generation companies, vast amounts of specialized data and expert knowledge have been accumulated. However, challenges such as data silos and fragmented knowledge hinder the effective utilization of this information. This study proposes a novel framework for intelligent Question-and-Answer (Q&A) systems based on Retrieval-Augmented Generation (RAG) to address these issues. The system efficiently acquires domain-specific knowledge by leveraging external databases, including Relational Databases (RDBs) and graph databases, without additional fine-tuning for Large Language Models (LLMs). Crucially, the framework integrates a Dynamic Knowledge Base Updating Mechanism (DKBUM) and a Weighted Context-Aware Similarity (WCAS) method to enhance retrieval accuracy and mitigate inherent limitations of LLMs, such as hallucinations and lack of specialization. Additionally, the proposed DKBUM dynamically adjusts knowledge weights within the database, ensuring that the most recent and relevant information is utilized, while WCAS refines the alignment between queries and knowledge items by enhanced context understanding. Experimental validation demonstrates that the system can generate timely, accurate, and context-sensitive responses, making it a robust solution for managing complex business logic in specialized industries.展开更多
The mass flow rate of a granular flow through an aperture under gravity is a long-standing challenge issue in physical science. We show that for steady flow field close to laminar flow, the dynamical equations togethe...The mass flow rate of a granular flow through an aperture under gravity is a long-standing challenge issue in physical science. We show that for steady flow field close to laminar flow, the dynamical equations together with the continue equation and Mohr-circle description of the stress are closed, and hence solvable. In a case of streamline guided by the two-dimensional hopper, we obtain a consistent condition and use it to determine the stress and the velocity distribution. Our result indicates that 3/2 power scaling behavior is recovered with a coefficient C(μ,α) being a function of frictional coefficient and the hopper angle. It is found that the predicted coefficient C(μ,α) is compatible with previous studies.展开更多
The 1H and 13C NMR spectra of the dinuclear complexes of molybdenum(VI) withethylenediaminetetraacetic acid ([Mo(VI)]2-EDTA) and 3,12-bis(carboxymethyl)-6.9-dioxa-3,12-diazatetra-decanedioic acid(tMo(VI)]2-EGTA) at va...The 1H and 13C NMR spectra of the dinuclear complexes of molybdenum(VI) withethylenediaminetetraacetic acid ([Mo(VI)]2-EDTA) and 3,12-bis(carboxymethyl)-6.9-dioxa-3,12-diazatetra-decanedioic acid(tMo(VI)]2-EGTA) at various temperatures were measured. The solutionstructure of the two dinuclear complexes was determined and the possible exchange process of theisomers is suggested展开更多
The U-Nb alloy,as a kind of nuclear material with good corrosion resistance and mechanical properties,plays an important role in the nuclear industry.However,the experimental measurements and theoretical calculations ...The U-Nb alloy,as a kind of nuclear material with good corrosion resistance and mechanical properties,plays an important role in the nuclear industry.However,the experimental measurements and theoretical calculations of many parameters which are essential in describing the dynamical properties of this alloy melt,including density,diffusivity,and viscosity,have not been carried out yet.The lack of data on the dynamical properties of nuclear materials seriously hinders the high-performance nuclear materials from being developed and applied.In this work,the dynamical properties of the U-Nb alloy melt are systematically studied by means of ab initio molecular dynamics simulations and their corresponding mathematical models are established,thereby being able to rapidly calculate the densities,diffusion coefficients,viscosities,and their activation energies in the whole U-Nb liquid region.This work provides a new idea for investigating the dynamical properties of binary alloy melts,thereby promoting the development of melt research.展开更多
文摘Sperber ＆ Wilson point out the cognitive nature of context when they explicate relevance theory. Cognitive context exerts its function dynamically. The process of communication is the participation of cognitive context. Without cognitive context, the verbal communication can not be realized.
文摘How to make college English teaching （CET） tailed to the requirement of the society is a topic of great significance. This paper is meant to give a description of CET from a new aspect——dynamic context. By giving an analysis of the current situation of CET in China as well as the introduction of the theory of DC, this paper attempts to give a description of CET in dynamic contexts （DC） to improve the students＇ communicative competence to meet the need of the society.
文摘This numerical study of the Bohai Sea wintertime circulation by means of a two dimensional barotropic model with resolution of 1/24° in longitude and latitude showed that the Bohai Sea wintertime circulation is dominated by local monsoon winds. The major current components include the Bohai Warm Current, the North Shandong Coastal Current, and the Liaodong Gyre. The Bohai Warm Current originates from the Yellow Sea Warm Current at the northern part of Bohai Strait, meanders westwards and finally enters the northern part of Bohai Bay. The North Shandong Coastal Current flows along the southwest shore of Bohai Bay and Laizhou Bay and exits from the Bohai Sea through the south Bohai Strait. The anticyclonic Liaodong Gyre is located in the north of Liaodong Bay. A pair of eddies and the small scale Jinzhou Gyre are found between the Bohai Warm Current and the Liaodong Gyre. The computed volume transport for both the Bohai Warm Current and North Shandong Coastal Current is about 0.03 Sv (1 Sv=1×10 6 m 3/s). The numerical experiments showed that the combined effect of local monsoon winds and bottom topography dominate the formation of the circulation pattern. The Coriolis force and the wind stress curl are of certain importance. The beta effect, the momentum advection and the open boundary condition have little influence on the circulation pattern.
文摘Verschueren's Theory of Adaptation argues that the process of using language is the result of the language users consciously make continuous linguistic choices and adapt to the contexts, consciously or unconsciously, for language-internal and/or language-external reasons. The contextual adaptation well explains the characteristics of dynamic contextual development in diplomatic escort interpreting. It is helpful for interpreters to understand that the choice-making was constrained by different contexts in diplomatic interpreting. In addition, interpreters should adapt to the various factors of the context thus can make flexible and appropriate choices in delivering target language in order to promote the quality of interpretation and achieve the satisfactory communicative effect.
文摘Requirements of software systems tend to change over time. The speed of this tendency depends on the application domain the software system under consideration belongs to. If we consider novel contexts such as pervasive systems and systems supporting dynamic B2B interaction, requirements change so fast that the research community is studying how to build systems that are able to self-adapt on the fly to some of these changes. When this happens, the system does not need to undergo through a new development cycle thus increasing its availability and, to a certain extent, its robustness. So far, the research in the area of self-adaptive systems has been focusing on the definition of the mechanisms for supporting self-adaptation. We argue that what is missing now is a structured and robust design process associated to these mechanisms. This design process should include a Requirement Engineering (RE) phase that somewhat differs from the traditional one. However, the identification of requirements for adaptation requires a good knowledge of the context in which the system will be executed. In this work, we consider the modeling of such context as part of the RE phase and we particularly focus on Service-Based Applications (SBAs). We argue that RE activities should be supported at run-time to handle context changes and to support adaptation for SBAs. We survey the state of the art for what concerns the elicitation, modeling, and analysis of requirements and will highlight some issues and challenges in order to support adaptation for SBAs.
文摘Taken discourse production as the research objective,it holds that discourse production is dynamic in human communication.It attempts to analyze the dynamics on the basis of Relevance-adaption model from the perspective of cognitive pragmatics and explain the role of the context dynamics that plays in the discourse production.
基金supported in part by the European Regional Development Fund under Grant KK.01.1.1.01.0009(DATACROSS).
文摘This paper deals with reduction of losses in electric power distribution system through a dynamic reconfiguration case study of a grid in the city of Mostar,Bosnia and Herzegovina.The proposed solution is based on a nonlinear model predictive control algorithm which determines the optimal switching operations of the distribution system.The goal of the control algorithm is to find the optimal radial network topology which minimizes cumulative active power losses and maximizes voltages across the network while simultaneously satisfying all system constraints.The optimization results are validated through multiple simulations(using real power demand data collected for a few characteristic days during winter and summer)which demonstrate the efficiency and usefulness of the developed control algorithm in reducing the grid losses by up to 14%.
文摘Definition of termsInputs can be defined as everything which students bring tothe classroom including their prior teaching and learningenvironment,attitude,enthusiasm,motivation,phonologyfrom their first language and varying degrees of confidence.When they arrive in college they are exposed to spoken Englishfrom a range of teachers who have a variety of spoken abilitiesand teaching techniques.
基金supported by the National Natural Science Foundation of China (81571658 and U1632274)the Social Science Foundation of China (15ZDB016)
文摘Becoming a mother is one of the most monumental experiences in a woman's lifetime. Women typically bear the primary caregiving responsibility for their infants, and they undergo numerous changes both mentally and physically, including behavioral, emotional, and hormonal changes, during the postpartum period. Studies have indicated that hormonal, experiential, and temporal factors significantly regulate emotional and cognitive brain functions during the postpartum period [1]. The determination of the neural basis of a maternal brain is critically important for understanding mother-infant attachments and thus perpetuating the human species. Until recently, limited investigations of the neuroanatomical and functional status of mothers have contributed to understanding the processing of maternal behaviors.
基金Projects(50674040, 50539090) supported by the National Natural Science Foundation of ChinaProject(CX07B_128z) supported by the Cultivate Creative Postgraduate Foundation of Jiangsu Province, China
文摘A new meso-mechanical testing scheme based on SEM was developed to carry out the experiment of microfracturing process of rocks. The microfracturing process of the pre-crack marble sample on surrounding rock in the immerged Long-big tunnel in Jinping Cascade II Hydropower Station under uniaxial compression was recorded by using the testing scheme. According to the stereology theory, the propagation and coalescent of cracks at meso-scale were quantitatively investigated with digital technology. Therefore, the basic geometric information of rock microcracks such as area, angle, length, width, perimeter, was obtained from binary images after segmentation. The failure mechanism of specimen under uniaxial compression with the quantitative information was studied from macro and microscopic point of view. The results show that the image of microfracturing process of the specimen can be observed and recorded digitally. During the damage of the specimen, the distribution of microcracks in the specimen is still subjected to exponential distribution with some microcracks concentrated in certain regions. Finally, the change law of the fractal dimension of the local element in marble sample under different external load conditions is obtained by means of the statistical calculation of the fractal dimension.
基金the National Natural Science Foundation of China (No. 29876035).
文摘An experimental apparatus composed of microscope, video camera. image-processing, and mini reactor which can be used for real-time measurement of the growth of polymer particle in gas phase polymerization was built up to carry out dynamic study of gas phase polymerization of butadiene by heterogeneous catalyst based on neodymium(Nd). The studies of the shape duplication of polymer particles and catalyst particles and the growth rate of polymer particle were made. Results show that the apparatus and procedure designed can be well utilized to make dynamic observation and data collection of the growth of polymer particle in gas phase polymerization. A phenomenon of shape duplication of polymer particles and catalyst particles was observed by the real-time measurement. The result also concludes that the activity of individual catalyst particle is different, and the effect of reaction pressure on the growth of polymer particle is significant.
基金financially supported by the National Natural Science Foundation of China(No.51922026)the Fundamental Research Funds for the Central Universities(Nos.N2002005 and N2007011)+1 种基金the Liaoning Natural Science Foundation(No.20180510010)the 111 Project(No.B20029)。
文摘Mechanical properties of high-entropy alloys(HEAs)with the face-centered cubic(fcc)structure strongly depend on their initial grain orientations.However,the orientation-dependent mechanical responses and the underlying plastic fl ow mechanisms of such alloys are not yet well understood.Here,deformation of the equiatomic FeMnCoCrNi HEA with various initial orientations under uniaxial tensile testing has been studied by using atomistic simulations,showing the results consistent with the recent experiments on fcc HEAs.The quantitative analysis of the activated deformation modes shows that the initiation of stacking faults is the main plastic deformation mechanism for the crystals initially oriented with[001],[111],and[112],and the total dislocation densities in these crystals are higher than that with the[110]and[123]orientations.Stacking faults,twinning,and hcp-martensitic transformation jointly promote the plastic deformation of the[110]orientation,and twinning in this crystal is more significant than that with other orientations.Deformation in the crystal oriented with[123]is dominated by the hcp-martensite transformation.Comparison of the mechanical behaviors in the FeMnCoCrNi alloy and the conventional materials,i.e.Cu and Fe50Ni50,has shown that dislocation slip tends to be activated more readily in the HEA.This is attributed to the larger lattice distortion in the HEA than the low-entropy materials,leading to the lower critical stress for dislocation nucleation and elastic–plastic transition in the former.In addition,the FeMnCoCrNi HEA with the larger lattice distortion leads to an enhanced capacity of storing dislocations.However,for the[001]-oriented HEA in which dislocation slip and stacking fault are the dominant deformation mechanisms,the limited deformation modes activated are insu fficient to improve the work hardening ability of the material.
文摘FITC-conjugated nanoferrofluid (FNFF) was synthesized and characterized to study the dynamic of laser-induced transport of NPs in water. The results confirmed a definite laser-induced enhanced velocity of NPs (100 μm⋅s−1) almost twice as much the without laser (i.e. Brownian motion). The diffusion coefficients of 17 × 10−6 m2⋅s−1 and 55 × 10−6 m2⋅s−1 were found for the cases without and with laser action respectively. The act of laser when switched on after NPs had reached the steady state was very prominent. The laser-induced heat and power generated by NPs were calculated 0.2μW⋅cm−3 and 0.4 pW⋅cm−2 respectively. Our experiment condition was non-adiabatic and that the heat generated was diffused into the surrounding. We considered the Maxwell’s criteria (Kp/Kw −1⋅K−1. Based on the Brownian diffusion and DLVO theory, at earlier times where the NPs are more dispersed within the medium are displaced faster. However, at later stages they become less mobile as they are agglomerated. The mechanisms for the enhanced mobility and laser transport of NPs are thought to be due to e.m.w induced force (i.e. an oscillatory motion) and laser absorptive force (i.e., photothermophoresis). A beam divergence of about 5.24°(or 91 mrad) was determined. A non-linear behaviour of laser beam was observed as a trajectory path within the water due to thermal heating hence causing the change of refractive index of medium and redistribution of NPs concentration.
基金supported by the Foundation for Innovative Research Groups of National Natural Science Foundation of China(No.51121004)National Natural Science Foundation of China(No.50976026)
文摘A numerical investigation is conducted to explore the evolution of a plasma discharge and its interaction with the fluid flow based on a self-consistent fluid model which couples the discharge dynamics with the fluid dynamics.The effects of the applied voltage on the distribution of velocity and temperature in initially static air are parainetrically studied.Furthermore,the spatial structure of plasma discharge and the resulting force contours in streamwise and normal directions are discussed in detail.The result shows that the plasma actuator produces a net force that should always be directed away from the exposed electrode,which results in an ionic wind pushing particles into a jet downstream of the actuator.When the energy added by the plasma is taken into account,the ambient air temperature is increased slightly around the electrode,but the velocity is almost not affected.Therefore it is unlikely that the induced flow is buoyancy driven.For the operating voltages considered in this paper,the maximum induced velocity is found to follow a power law,i.e.,it is proportional to the applied voltage to the 3.5 power.This promises an efficient application in the flow control with plasma actuators.
文摘In the context of power generation companies, vast amounts of specialized data and expert knowledge have been accumulated. However, challenges such as data silos and fragmented knowledge hinder the effective utilization of this information. This study proposes a novel framework for intelligent Question-and-Answer (Q&A) systems based on Retrieval-Augmented Generation (RAG) to address these issues. The system efficiently acquires domain-specific knowledge by leveraging external databases, including Relational Databases (RDBs) and graph databases, without additional fine-tuning for Large Language Models (LLMs). Crucially, the framework integrates a Dynamic Knowledge Base Updating Mechanism (DKBUM) and a Weighted Context-Aware Similarity (WCAS) method to enhance retrieval accuracy and mitigate inherent limitations of LLMs, such as hallucinations and lack of specialization. Additionally, the proposed DKBUM dynamically adjusts knowledge weights within the database, ensuring that the most recent and relevant information is utilized, while WCAS refines the alignment between queries and knowledge items by enhanced context understanding. Experimental validation demonstrates that the system can generate timely, accurate, and context-sensitive responses, making it a robust solution for managing complex business logic in specialized industries.
基金Supported by the Key Research Program of Frontier Science of the Chinese Academy of Sciences under Grant No QYZDYSSW-SYS006
文摘The mass flow rate of a granular flow through an aperture under gravity is a long-standing challenge issue in physical science. We show that for steady flow field close to laminar flow, the dynamical equations together with the continue equation and Mohr-circle description of the stress are closed, and hence solvable. In a case of streamline guided by the two-dimensional hopper, we obtain a consistent condition and use it to determine the stress and the velocity distribution. Our result indicates that 3/2 power scaling behavior is recovered with a coefficient C(μ,α) being a function of frictional coefficient and the hopper angle. It is found that the predicted coefficient C(μ,α) is compatible with previous studies.
文摘The 1H and 13C NMR spectra of the dinuclear complexes of molybdenum(VI) withethylenediaminetetraacetic acid ([Mo(VI)]2-EDTA) and 3,12-bis(carboxymethyl)-6.9-dioxa-3,12-diazatetra-decanedioic acid(tMo(VI)]2-EGTA) at various temperatures were measured. The solutionstructure of the two dinuclear complexes was determined and the possible exchange process of theisomers is suggested
基金Project supported by the Science Challenging Project,China(Grant No.TZ2016004)the National Natural Science Foundation of China(Grant No.51701193)。
文摘The U-Nb alloy,as a kind of nuclear material with good corrosion resistance and mechanical properties,plays an important role in the nuclear industry.However,the experimental measurements and theoretical calculations of many parameters which are essential in describing the dynamical properties of this alloy melt,including density,diffusivity,and viscosity,have not been carried out yet.The lack of data on the dynamical properties of nuclear materials seriously hinders the high-performance nuclear materials from being developed and applied.In this work,the dynamical properties of the U-Nb alloy melt are systematically studied by means of ab initio molecular dynamics simulations and their corresponding mathematical models are established,thereby being able to rapidly calculate the densities,diffusion coefficients,viscosities,and their activation energies in the whole U-Nb liquid region.This work provides a new idea for investigating the dynamical properties of binary alloy melts,thereby promoting the development of melt research.
