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Experimental Study on the Wavelengths of Two-Dimensional and Three-Dimensional Freak Waves
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作者 CUI Cheng PAN Wen-bo 《China Ocean Engineering》 SCIE EI CSCD 2023年第1期154-164,共11页
Freak waves are commonly characterized by strong-nonlinearity, and the wave steepness, which is calculated from the wavelength, is a measure of the degree of the wave nonlinearity. Moreover, the wavelength can describ... Freak waves are commonly characterized by strong-nonlinearity, and the wave steepness, which is calculated from the wavelength, is a measure of the degree of the wave nonlinearity. Moreover, the wavelength can describe the locally spatial characteristics of freak waves. Generally, the wavelengths of freak waves are estimated from the dispersion relations of Stokes waves. This paper concerns whether this approach enables a consistent estimate of the wavelength of freak waves. The two-(unidirectional, long-crested) and three-dimensional(multidirectional, shortcrested) freak waves are simulated experimentally through the dispersive and directional focusing of component waves, and the wavelengths obtained from the surface elevations measured by the wave gauge array are compared with the results from the linear, 3rd-order and 5th-order Stokes wave theories. The comparison results suggest that the 3rd-order theory estimates the wavelengths of freak waves with higher accuracy than the linear and 5th-order theories. Furthermore, the results allow insights into the dominant factors. It is particularly noteworthy that the accuracy is likely to depend on the wave period, and that the wavelengths of longer period freak waves are overestimated but the wavelengths are underestimated for shorter period ones. In order to decrease the deviation, a modified formulation is presented to predict the wavelengths of two-and three-dimensional freak waves more accurately than the 3rd-order dispersion relation, by regression analysis. The normalized differences between the predicted and experimental results are over 50% smaller for the modified model suggested in this study compared with the 3rd-order dispersion relation. 展开更多
关键词 freak wave rogue wave WAVELENGTH three-dimension directional spread multidirectional wave
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Rule acquisition of three-way semi-concept lattices in formal decision context
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作者 Jie Zhao Renxia Wan +1 位作者 Duoqian Miao Boyang Zhang 《CAAI Transactions on Intelligence Technology》 SCIE EI 2024年第2期333-347,共15页
Three-way concept analysis is an important tool for information processing,and rule acquisition is one of the research hotspots of three-way concept analysis.However,compared with three-way concept lattices,three-way ... Three-way concept analysis is an important tool for information processing,and rule acquisition is one of the research hotspots of three-way concept analysis.However,compared with three-way concept lattices,three-way semi-concept lattices have three-way operators with weaker constraints,which can generate more concepts.In this article,the problem of rule acquisition for three-way semi-concept lattices is discussed in general.The authors construct the finer relation of three-way semi-concept lattices,and propose a method of rule acquisition for three-way semi-concept lattices.The authors also discuss the set of decision rules and the relationships of decision rules among object-induced three-way semi-concept lattices,object-induced three-way concept lattices,classical concept lattices and semi-concept lattices.Finally,examples are provided to illustrate the validity of our conclusions. 展开更多
关键词 finer relation rule acquisition three-way concept analysis three-way semi-concept lattices
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Learning of Concepts: A Review of Relevant Advances Since 2010 and Its Inspirations for Teaching
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作者 Zhong Wang 《Journal of Contemporary Educational Research》 2024年第6期1-15,共15页
This article reviews the psychological and neuroscience achievements in concept learning since 2010 from the perspectives of individual learning and social learning,and discusses several issues related to concept lear... This article reviews the psychological and neuroscience achievements in concept learning since 2010 from the perspectives of individual learning and social learning,and discusses several issues related to concept learning,including the assistance of machine learning about concept learning.In terms of individual learning,current evidence shows that the brain tends to process concrete concepts through typical features(shared features);and for abstract concepts,semantic processing is the most important cognitive way.In terms of social learning,interpersonal neural synchrony(INS)is considered the main indicator of efficient knowledge transfer(such as teaching activities between teachers and students),but this phenomenon only broadens the channels for concept sources and does not change the basic mode of individual concept learning.Ultimately,this article argues that the way the human brain processes concepts depends on the concept’s own characteristics,so there are no“better”strategies in teaching,only more“suitable”strategies. 展开更多
关键词 concept learning Concrete concepts Abstract concepts Interpersonal neural synchrony Machine learning Review
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Value and Measures of Integrating Local Red Culture into the Ideological and Political Course of Environmental Disciplines under the OBE Concept
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作者 Xiong YAN Wenzhao LI +5 位作者 Shenwen CAI Bailian XIONG Liumei CHEN Junwei CHENG Qinghe WANG Leilei FAN 《Asian Agricultural Research》 2024年第2期40-42,共3页
Based on output-oriented education,the OBE(Outcome-Based Education)concept integrates local red culture into the ideological and political course of environmental disciplines,and is an important part of training appli... Based on output-oriented education,the OBE(Outcome-Based Education)concept integrates local red culture into the ideological and political course of environmental disciplines,and is an important part of training applied talents of environmental disciplines in the new era.This educational model makes an innovation on the traditional educational and teaching concepts and centers on students.This paper analyzes the value of integrating local red culture into the ideological and political course under the OBE concept,and puts forward an effective implementation path. 展开更多
关键词 OBE(Outcome-Based Education)concept Local red culture Environmental disciplines Ieological and political course
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Clinical Study of Applying Enhanced Recovery after Surgery Concept in Single-Segment Lumbar Spinal Stenosis Surgery
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作者 Yinwen Mai Weikang Yang +3 位作者 Yuanjian Huang Wanxia Lu Guosheng Su Chengkua Huang 《Open Journal of Therapy and Rehabilitation》 2024年第3期263-273,共11页
Objective: With the aging population and changes in lifestyle, lumbar spinal stenosis has become a common spinal disorder. Treatment modalities have been advancing, and the application of Enhanced Recovery After Surge... Objective: With the aging population and changes in lifestyle, lumbar spinal stenosis has become a common spinal disorder. Treatment modalities have been advancing, and the application of Enhanced Recovery After Surgery (ERAS) principles provides a new approach to postoperative recovery in patients. This study aims to investigate the clinical application effects of ERAS principles in single-level lumbar spinal stenosis surgery. Methods: This study included 64 patients who underwent lumbar fusion surgery in the Spinal Surgery Department of Baise People’s Hospital from July 2022 to July 2024. These patients were divided into an experimental group (ERAS group, 33 cases) and a control group (conventional group, 31 cases) based on perioperative care, receiving ERAS principles and traditional treatment, respectively. A comparison was made between the two groups in terms of gender, age, BMI, intraoperative blood loss, postoperative length of hospital stay, postoperative complications, hospital costs, VAS scores (preoperative/postoperative day 3), and ODI scores (preoperative/postoperative day 3). Results: There were no significant differences in gender, age, and BMI between the ERAS group and the conventional group (gender: χ2 = 0.5008, P = 0.4792;age: 54.55 ± 8.51 years vs. 57.39 ± 8.16 years, P = 0.0892;BMI: 25.11 ± 2.70 vs. 24.77 ± 2.75, P = 0.3098). However, during surgery, patients in the ERAS group had significantly less blood loss than those in the conventional group (197.58 ± 195.51ml vs. 438.71 ± 349.22 ml, P = 0.0006), and the postoperative length of hospital stay was significantly shorter (7.00 ± 2.24 days vs. 11.55 ± 5.23 days, P = 0.0000). On postoperative day 3, VAS scores were significantly better in the ERAS group compared to the conventional group (3.70 ± 0.88 vs. 4.32 ± 0.87, P = 0.0031), and the ODI scores showed significant improvement as well (46.00 ± 3.04 vs. 48.00 ± 3.39, P = 0.0078). Although there were no significant differences in postoperative complications and hospital costs (complications: 3 cases vs. 0 cases, P = 0.2154;hospital costs: 63524.29 ± 17891.80 RMB vs. 58733.84 ± 13280.82 RMB, P = 0.1154), ERAS demonstrated better postoperative recovery outcomes in single-level lumbar spinal stenosis surgery. Conclusion: The study results support the implementation of ERAS principles in single-level lumbar spinal stenosis surgery to promote rapid recovery, reduce healthcare resource consumption, and improve overall patient satisfaction. 展开更多
关键词 Enhanced Recovery after Surgery concept Single-Segment Lumbar Spinal Stenosis Perioperative Period VAS Score ODI Score
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Conceptual Analysis of Self-Management in Patients with Hypertension
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作者 Li Yang Yutian Hao +4 位作者 Liling Zhong Shilin Xu Saiqiong Zhong Yanying Lu Hui Liu 《Journal of Clinical and Nursing Research》 2024年第5期356-368,共13页
Objective:To clarify the concept of self-management in hypertensive patients by analyzing the definition,attributes,and measurement tools through a literature review.Methods:An Internet-based search of the databases w... Objective:To clarify the concept of self-management in hypertensive patients by analyzing the definition,attributes,and measurement tools through a literature review.Methods:An Internet-based search of the databases was conducted using Academic Search Complete,Medical Line,CINAHL,Health Source:Nursing/Scholarly Edition,and Google Scholar.In the search process,keywords or free text were combined by using Boolean operators,with the search terms“self of management”or“self-management,”“concept*analysis”or“concept*definition,”and Walker and Avant’s concept analysis method was used.Results:Analysis of relevant literature summarized the conceptual attributes of self-management in hypertensive patients as the active participation of patients in the treatment process;the presence of interaction provided by patients and health care providers;the use of certain health management tools;and the aim of maintaining and improving the health status and living capacity of hypertensive patients.Conclusion:The concept of self-management for hypertensive patients was clarified,which helps to promote the application of hypertensive self-management in clinical work and improve outcomes and quality of life for patients with hypertension. 展开更多
关键词 HYPERTENSION SELF-MANAGEMENT concept analysis Walker and Avant’s concept analysis method
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The Sustainable Development Pathway of the Biomedical Industry Based on Environmental,Social,and Governance(ESG)Concepts
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作者 Yangyan Chen 《Proceedings of Business and Economic Studies》 2024年第1期133-138,共6页
There is a growing global awareness of environmental,social,and governance(ESG)concerns.The biopharmaceutical industry is an important field that affects human health and well-being,and its sustainable development is ... There is a growing global awareness of environmental,social,and governance(ESG)concerns.The biopharmaceutical industry is an important field that affects human health and well-being,and its sustainable development is now the industry’s focus.Based on the current state of the green development of China’s biopharmaceutical industry,the article proposes suggestions and paths for promoting the industry to better fulfill its social responsibilities and protect the environment while pursuing economic benefits.By doing so,the industry can make a greater contribution to global public health and become an important factor in promoting human health and social prosperity. 展开更多
关键词 ESG concept Biomedical industry Sustainable development
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Self-management in patients with diabetic foot ulcer:a concept analysis
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作者 Hui-Ren Zhuang Yong-Mei You +2 位作者 Qin Liu Hai-Ping Yu Minerva B.De Ala 《Frontiers of Nursing》 2024年第3期267-274,共8页
Objective:This paper presents an analysis of the concept of patient outcomes.Methods:The present study conducted searches on various databases,including Wanfang,Sinomed,CNKI,Pub Med,Cochrane Library,Embase,Web of Scie... Objective:This paper presents an analysis of the concept of patient outcomes.Methods:The present study conducted searches on various databases,including Wanfang,Sinomed,CNKI,Pub Med,Cochrane Library,Embase,Web of Science,and Ovid.The paper followed the Walker and Avant concept-analysis approach.Results:Initially,899 pieces of literature were identified through the search process,and after screening,41 of them were ultimately included in the analysis.The identified attributes of the concept included(1)capability,(2)decision making,and(3)action.These antecedents were shaped by factors such as illness perception,self-efficacy,and family and social.The consequences included(1)physiological effects,(2)psychological effects,and(3)social influence.Conclusions:The concept analysis of self-management in patients with diabetic foot ulcers(DFUs)not only aids in clinical practice and suppor ts interventions,but also contributes to the development of self-management theory.The common goal of clinical medical staff is to assist DFU patients in improving cognitive ability,making correct self-management decisions,and enhancing self-management behavior. 展开更多
关键词 conceptION conceptual analysis DFU diabetic foot ulcer SELF-MANAGEMENT
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Progress in The Application of Nursing Care Based on ERAS Concept after Thoracolumbar Fracture Surgery
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作者 Ruigang Zhu Limiao Cui Rui Zhou 《Journal of Clinical and Nursing Research》 2024年第3期141-146,共6页
Thoracic spine fracture is a common orthopedic injury that is usually caused by external forces acting directly on or transmitted to the thoracic spine through other parts of the spine.Thoracic spine fractures can be ... Thoracic spine fracture is a common orthopedic injury that is usually caused by external forces acting directly on or transmitted to the thoracic spine through other parts of the spine.Thoracic spine fractures can be divided into two types:stable and unstable.An unstable fracture means that the relationship between the vertebral bodies is no longer stable,which may cause serious consequences such as spinal compression,nerve root compression,or spinal cord injury.Surgical treatment is often needed for patients with unstable fractures,nerve root compression,or spinal cord injury to restore stability and function to the thoracic spine.The probability of complications after thoracolumbar fracture surgery is high,which affects the outcome of surgical treatment.To improve postoperative rehabilitation outcomes,this article analyzed the value of nursing care based on the enhanced recovery after surgery(ERAS)concept for patients undergoing thoracolumbar fracture surgery. 展开更多
关键词 ERAS concept NURSING Thoracolumbar fracture surgery Application progress
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Mountain Highway Design Based on New Green Design Concepts
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作者 Zhuang Hu Yazhou Liu 《Journal of World Architecture》 2024年第2期118-122,共5页
This article analyzes the implementation of new environmentally friendly design practices in the construction of mountain highways.It covers topics such as green highway design concepts,alignment principles,and green ... This article analyzes the implementation of new environmentally friendly design practices in the construction of mountain highways.It covers topics such as green highway design concepts,alignment principles,and green practices specifically for mountainous highway design.This analysis aims to provide useful insights for creating green mountain highways that meet the demands of modern times. 展开更多
关键词 Mountainous areas HIGHWAYS Green design concepts
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Family resilience of cancer patients:a concept analysis
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作者 Ge-Ge Han 《Frontiers of Nursing》 2024年第2期153-158,共6页
Objective:The concept of family resilience of cancer patients was discussed through literature review,which provided reference for nursing of cancer patients.Methods:China National Knowledge Infrastructure(CNKI),Wanfa... Objective:The concept of family resilience of cancer patients was discussed through literature review,which provided reference for nursing of cancer patients.Methods:China National Knowledge Infrastructure(CNKI),Wanfang Database,SinoMed,PubMed,Web of Science,and Embase were systematically searched,and the concept analysis method proposed by Walker and Avant was adopted.Results:In this study,we defined the concept of family resilience,identified attributes,and analyzed the antecedents and consequences.The proposed operational definition of family resilience was:After a family member is diagnosed with cancer,the whole family can actively explore its own unique internal and external resources and advantages,strengthen self-regulation,jointly cope with the crisis by establishing close family relationships,providing mutual support to family members,and interacting with the outside world.Conclusions:The definition of family resilience of cancer patients is conducive to the development of measurement tools and the improvement of family outcomes of adult cancer patients by intervening family resilience factors. 展开更多
关键词 cancer patients concept analysis family resilience literature review nursing care
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Exploration of Practice Teaching Reform Based on Outcome-Based Education Concept:Taking Environmental Design Major as an Example
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作者 Yushan Pang 《Journal of Contemporary Educational Research》 2024年第5期74-79,共6页
The concept of OBE(outcome-based education)is more focused on designing and implementing teaching activities around expected learning outcomes than the traditional teaching model and enhancing the quality of education... The concept of OBE(outcome-based education)is more focused on designing and implementing teaching activities around expected learning outcomes than the traditional teaching model and enhancing the quality of education through clear and measurable learning outcomes,which has led to profound changes in the field of education.However,environmental design practice teaching faces a series of challenges in the implementation of the OBE concept,including the complexity of the assessment system,personalized learning and creative learning,and over-reliance on quantitative assessment.Therefore,in order to further deepen the professionalization of the OBE concept,we have conducted research on the design education practice models at home and abroad,explored the practice teaching models and their applications such as project system,studio model,practical internships,and technology-driven interdisciplinary integration,and took the practice innovative teaching models of Stanford d.school and Rhode Island School of Design(RISD)as examples to explore the characteristics of the curricula,cultivation modes,and the development of the environmental design professional practice teaching model.The characteristics of OBE and RISD are discussed to provide a global vision and local contextual reference for the practice teaching reform of environmental design majors. 展开更多
关键词 Outcome-based education(OBE)concept Practice teaching system Teaching reform Environmental design
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Reform of Hospitality English Teaching Based on the Educational Concept of Outcome-Based Education(OBE)
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作者 Chong Zhang 《Journal of Contemporary Educational Research》 2024年第1期58-64,共7页
The Outcome-Based Education(OBE)educational concept,proposed by renowned American educator Spady,aims to guide students in mastering learning laws and ultimately achieving expected learning outcomes.The application of... The Outcome-Based Education(OBE)educational concept,proposed by renowned American educator Spady,aims to guide students in mastering learning laws and ultimately achieving expected learning outcomes.The application of OBE educational concept in Hospitality English curriculum not only can effectively enhance the learning effect but also promote the reform of the Hospitality English curriculum,thus improving students’learning enthusiasm.Therefore,taking the Hospitality English curriculum as an example,this paper points out the existing problems in the teaching of this course and suggests the reform measures based on the OBE teaching concept,hoping to provide guidelines for related educational work. 展开更多
关键词 Outcome-Based Education(OBE)educational concept Hospitality English curriculum Teaching reform Practical strategy
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Research on the Teaching Design of Advanced Mathematics Courses Based on Outcome-Based Education Concept
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作者 Xinyu Huang 《Journal of Contemporary Educational Research》 2024年第6期148-154,共7页
This paper first analyzes the characteristics and current situation of the Advanced Mathematics course;secondly,it proposes a teaching model that integrates the outcome-based education(OBE)philosophy and blended teach... This paper first analyzes the characteristics and current situation of the Advanced Mathematics course;secondly,it proposes a teaching model that integrates the outcome-based education(OBE)philosophy and blended teaching method,reorganizing the teaching objectives,teaching content,and assessment evaluation process of the Advanced Mathematics course;lastly,through practice,it is proved that this approach can effectively improve students’mastery of course content,enhance students’ability to apply mathematical knowledge,and strengthen teaching effectiveness. 展开更多
关键词 Advanced Mathematics Outcome-based education concept Blended teaching method Online publication:July 3 2024
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Three-Dimensional Tidal Model and Its Application to Numerical Simulation of Water Quality in Coastal Waters 被引量:5
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作者 Shen Yongming , Li Yucheng and Zhao Wenqian Associate Professor, Department of Civil Engineering, Dalian University of Technology, Dalian 116023 Professor, Department of Civil Engineering, Dalian University of Technology, Dalian 116023 Professor, Department of Civil Engineering, Sichuan Union University, Chengdu 610065 《China Ocean Engineering》 SCIE EI 1994年第4期425-436,共12页
The turbulence mechanism plays an important part in the mixing process and momentum transfer of turbulence. A three-dimensional Prandtl mixing length tidal model has been developed to simulate tidal flows and water qu... The turbulence mechanism plays an important part in the mixing process and momentum transfer of turbulence. A three-dimensional Prandtl mixing length tidal model has been developed to simulate tidal flows and water quality. The eddy viscosities and diffusivities are computed from the Prandtl mixing length model. In order to model the water quality of an estuary or coastal area many interdependent processes need to be simulated. These may be conveniently separated into three main groups: transport and mixing processes, biochemical interaction of water quality variables and the utilization and re-cycling of nutrients by living matter. The model simulates full oxygen and nutrient balance, primary productivity and the transport, reaction mechanism and fate of pollutants over tidal time-scales. The model is applied to numerical simulation of tidal flows and water quality in Dalian Bay. The model has been calibrated against a limited data set of historical water quality observations and in general demonstrates excellent agreement with all available data. 展开更多
关键词 three-dimension tidal flows water quality ECOSYSTEM mixing length model coastal waters
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Three-dimensional Computational Fluid Dynamics Modeling of Two-phase Flow in a Structured Packing Column 被引量:4
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作者 张小斌 姚蕾 +1 位作者 邱利民 张学军 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第9期959-966,共8页
Characterizing the complex two-phase hydrodynamics in structured packed columns requires a power- ful modeling tool. The traditional two-dimensional model exhibits limitations when one attempts to model the de- tailed... Characterizing the complex two-phase hydrodynamics in structured packed columns requires a power- ful modeling tool. The traditional two-dimensional model exhibits limitations when one attempts to model the de- tailed two-phase flow inside the columns. The present paper presents a three-dimensional computational fluid dy- namics (CFD) model to simulate the two-phase flow in a representative unit of the column. The unit consists of an CFD calculations on column packed with Flexipak 1Y were implemented within the volume of fluid (VOF) mathe- matical framework. The CFD model was validated by comparing the calculated thickness of liquid film with the available experimental data. Special attention was given to quantitative analysis of the effects of gravity on the hy- drodynamics. Fluctuations in the liquid mass flow rate and the calculated pressure drop loss were found to be quali- tatively in agreement with the experimental observations. 展开更多
关键词 structured packing column two-phase flow computational fluid dynamics three-dimension
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Three-Dimensional and Cross-sectional Characteristics of Normal Grain Growth Based on Monte Carlo Simulation 被引量:3
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作者 Xiaoyan Song Guoquan Liu(Material Science and Engineering School, University of Science and Technology Beijing, Beijing 100083, China)(Department of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, China) 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 1998年第3期129-133,139,共6页
An appropriate Monte Carlo method was developed to simulate the three-dimensional normal grain growth more completely. Comparative investigation on the three-dimensional and the cross-sectional characteristics of norm... An appropriate Monte Carlo method was developed to simulate the three-dimensional normal grain growth more completely. Comparative investigation on the three-dimensional and the cross-sectional characteristics of normal grain growth was done. It was found that the time exponent of grain growth determined from cross-section exhibits the same rule of increasing slowly with time and approaching the theoretical value n = 0.5 of steadygrain growth as the three-dimensional (3-D) system. From change of the number of grains per unit area with timemeasured in cross-section, the state of 3-D normal grain growth may be predicted. The gtain size distribution incross-section is different from that in 3-D system and can not express the evolution characteristic of the 3-D distribution. Furthermore, there exists statistical connection between the topological parameters in cross-section and thosein three-dimensions. 展开更多
关键词 Monte Carlo simulation normal grain growth three-dimension cross-section CHARACTERISTICS
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Three-dimensional frequency-domain full waveform inversion based on the nearly-analytic discrete method 被引量:4
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作者 DeYao Zhang WenYong Pan +3 位作者 DingHui Yang LingYun Qiu XingPeng Dong WeiJuan Meng 《Earth and Planetary Physics》 CSCD 2021年第2期149-157,共9页
The nearly analytic discrete(NAD)method is a kind of finite difference method with advantages of high accuracy and stability.Previous studies have investigated the NAD method for simulating wave propagation in the tim... The nearly analytic discrete(NAD)method is a kind of finite difference method with advantages of high accuracy and stability.Previous studies have investigated the NAD method for simulating wave propagation in the time-domain.This study applies the NAD method to solving three-dimensional(3D)acoustic wave equations in the frequency-domain.This forward modeling approach is then used as the“engine”for implementing 3D frequency-domain full waveform inversion(FWI).In the numerical modeling experiments,synthetic examples are first given to show the superiority of the NAD method in forward modeling compared with traditional finite difference methods.Synthetic 3D frequency-domain FWI experiments are then carried out to examine the effectiveness of the proposed methods.The inversion results show that the NAD method is more suitable than traditional methods,in terms of computational cost and stability,for 3D frequency-domain FWI,and represents an effective approach for inversion of subsurface model structures. 展开更多
关键词 three-dimension FREQUENCY-DOMAIN NAD method forward modeling full waveform inversion
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The three-dimension model for the rock-breaking mechanism of disc cutter andanalysis of rock-breaking forces 被引量:23
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作者 Zhao-Huang Zhang Fei Sun 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第3期675-682,共8页
To study the rock deformation with three- dimensional model under rolling forces of disc cutter, by car- rying out the circular-grooving test with disc cutter rolling around on the rock, the rock mechanical behavior u... To study the rock deformation with three- dimensional model under rolling forces of disc cutter, by car- rying out the circular-grooving test with disc cutter rolling around on the rock, the rock mechanical behavior under rolling disc cutter is studied, the mechanical model of disc cutter rolling around the groove is established, and the the- ory of single-point and double-angle variables is proposed. Based on this theory, the physics equations and geometric equations of rock mechanical behavior under disc cutters of tunnel boring machine (TBM) are studied, and then the bal- ance equations of interactive forces between disc cutter and rock are established. Accordingly, formulas about normal force, rolling force and side force of a disc cutter are de- rived, and their validity is studied by tests. Therefore, a new method and theory is proposed to study rock- breaking mech- anism of disc cutters. 展开更多
关键词 Full face rock tunnel boring machine (TBM) Disc cutte three-dimension model
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Dynamic Characteristic Mechanism of Atrial Septal Defect Using Real-Time Three-Dimensional Echocardiography and Evaluation of Right Ventricular Functions 被引量:7
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作者 沙仁高娃 张军 +1 位作者 秦川 吕清 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2017年第1期140-147,共8页
The dynamic characteristics of the area of the atrial septal defect(ASD) were evaluated using the technique of real-time three-dimensional echocardiography(RT 3DE), the potential factors responsible for the dynami... The dynamic characteristics of the area of the atrial septal defect(ASD) were evaluated using the technique of real-time three-dimensional echocardiography(RT 3DE), the potential factors responsible for the dynamic characteristics of the area of ASD were observed, and the overall and local volume and functions of the patients with ASD were measured. RT 3DE was performed on the 27 normal controls and 28 patients with ASD. Based on the three-dimensional data workstations, the area of ASD was measured at P wave vertex, R wave vertex, T wave starting point, and T wave terminal point and in the T-P section. The right atrial volume in the same time phase of the cardiac cycle and the motion displacement distance of the tricuspid annulus in the corresponding period were measured. The measured value of the area of ASD was analyzed. The changes in the right atrial volume and the motion displacement distance of the tricuspid annulus in the normal control group and the ASD group were compared. The right ventricular ejection fractions in the normal control group and the ASD group were compared using the RT 3DE long-axis eight-plane(LA 8-plane) method. Real-time three-dimensional volume imaging was performed in the normal control group and ASD group(n=30). The right ventricular inflow tract, outflow tract, cardiac apex muscular trabecula dilatation, end-systolic volume, overall dilatation, end-systolic volume, and appropriate local and overall ejection fractions in both two groups were measured with the four-dimensional right ventricular quantitative analysis method(4D RVQ) and compared. The overall right ventricular volume and the ejection fraction measured by the LA 8-plane method and 4D RVQ were subjected to a related analysis. Dynamic changes occurred to the area of ASD in the cardiac cycle. The rules for dynamic changes in the area of ASD and the rules for changes in the right atrial volume in the cardiac cycle were consistent. The maximum value of the changes in the right atrial volume occurred in the end-systolic period when the peak of the curve appeared. The minimum value of the changes occurred in the end-systolic period and was located at the lowest point of the volume variation curve. The area variation curve for ASD and the motion variation curve for the tricuspid annulus in the cardiac cycle were the same. The displacement of the tricuspid annulus exhibited directionality. The measured values of the area of ASD at P wave vertex, R wave vertex, T wave starting point, T wave terminal point and in the T-P section were properly correlated with the right atrial volume(P〈0.001). The area of ASD and the motion displacement distance of the tricuspid annulus were negatively correlated(P〈0.05). The right atrial volumes in the ASD group in the cardiac cycle in various time phases increased significantly as compared with those in the normal control group(P=0.0001). The motion displacement distance of the tricuspid annulus decreased significantly in the ASD group as compared with that in the normal control group(P=0.043). The right ventricular ejection fraction in the ASD group was lower than that in the normal control group(P=0.032). The ejection fraction of the cardiac apex trabecula of the ASD patients was significantly lower than the ejection fractions of the right ventricular outflow tract and inflow tract and overall ejection fraction. The difference was statistically significant(P=0.005). The right ventricular local and overall dilatation and end-systolic volumes in the ASD group increased significantly as compared with those in the normal control group(P=0.031). The a RVEF and the overall ejection fraction decreased in the ASD group as compared with those in the normal control group(P=0.0005). The dynamic changes in the area of ASD and the motion curves for the right atrial volume and tricuspid annulus have the same dynamic characteristics. RT 3DE can be used to accurately evaluate the local and overall volume and functions of the right ventricle. The local and overall volume loads of the right ventricle in the ASD patients increase significantly as compared with those of the normal people. The right ventricular cardiac apex and the overall systolic function decrease. 展开更多
关键词 ultrasonic cardiography real-time three-dimension atrial septal defect tricuspid annulus right atrium
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