期刊文献+
共找到2,355篇文章
< 1 2 118 >
每页显示 20 50 100
Large language models and large concept models in radiology:Present challenges,future directions,and critical perspectives
1
作者 Suleman A Merchant Neesha Merchant +1 位作者 Shaju L Varghese Mohd Javed S Shaikh 《World Journal of Radiology》 2025年第11期1-38,共38页
Large language models(LLMs)have emerged as transformative tools in radiology artificial intelligence(AI),offering significant capabilities in areas such as image report generation,clinical decision support,and workflo... Large language models(LLMs)have emerged as transformative tools in radiology artificial intelligence(AI),offering significant capabilities in areas such as image report generation,clinical decision support,and workflow optimization.The first part of this manuscript presents a comprehensive overview of the current state of LLM applications in radiology,including their historical evolution,technical foundations,and practical uses.Despite notable advances,inherent architectural constraints,such as token-level sequential processing,limit their ability to perform deep abstract reasoning and holistic contextual understanding,which are critical for fine-grained diagnostic interpretation.We provide a critical perspective on current LLMs and discuss key challenges,including model reliability,bias,and explainability,highlighting the pressing need for novel approaches to advance radiology AI.Large concept models(LCMs)represent a nascent and promising paradigm in radiology AI,designed to transcend the limitations of token-level processing by utilizing higher-order conceptual representations and multimodal data integration.The second part of this manuscript introduces the foundational principles and theoretical framework of LCMs,highlighting their potential to facilitate enhanced semantic reasoning,long-range context synthesis,and improved clinical decision-making.Critically,the core of this section is the proposal of a novel theoretical framework for LCMs,formalized and extended from our group’s foundational concept-based models-the world’s earliest articulation of this paradigm for medical AI.This conceptual shift has since been externally validated and propelled by the recent publication of the LCM architectural proposal by Meta AI,providing a large-scale engineering blueprint for the future development of this technology.We also outline future research directions and the transformative implications of this emerging AI paradigm for radiologic practice,aiming to provide a blueprint for advancing toward human-like conceptual understanding in AI.While challenges persist,we are at the very beginning of a new era,and it is not unreasonable to hope that future advancements will overcome these hurdles,pushing the boundaries of AI in Radiology,far beyond even the most state-of-the-art models of today. 展开更多
关键词 Radiology artificial intelligence Large language models Large concept models Medical imaging artificial intelligence Artificial intelligence in healthcare Multimodal artificial intelligence models Explainable artificial intelligence Artificial intelligence model limitations and challenges Natural language processing in radiology conceptual reasoning in artificial intelligence
在线阅读 下载PDF
Improved concept models for straight thin-walled columns with box cross section 被引量:4
2
作者 Yu-cheng LIU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第11期1473-1479,共7页
This paper focuses on developing improved concept models for straight thin-walled box sectional columns which can better predict the peak crushing force that occurs during crashworthiness analyses. We develop a nonlin... This paper focuses on developing improved concept models for straight thin-walled box sectional columns which can better predict the peak crushing force that occurs during crashworthiness analyses. We develop a nonlinear translational spring based on previous research and apply such a spring element to build the enhanced concept models. The work presented in this article is developed on the basis of the publication of the author (Liu and Day, 2006b) and has been applied in a crashworthiness design issue, which is presented by the author in another paper (Liu, 2008). 展开更多
关键词 concept model Peak crushing force Box section Nonlinear translational springs Crashworthiness analysis Thin-walled column
在线阅读 下载PDF
ATMOSPHERIC BOUNDARY LAYER CONCEPT MODEL OF THE PEARL RIVER DELTA AND ITS APPLICATION 被引量:4
3
作者 范绍佳 王安宇 +3 位作者 樊琦 刘吉 王宝民 塔纳 《Journal of Tropical Meteorology》 SCIE 2007年第1期8-13,共6页
Based on the geographical circumstance, climate and the boundary layer meteorology features of the Pearl River Delta, a boundary layer concept model of the Pearl River Delta was built. The concept model consists of fo... Based on the geographical circumstance, climate and the boundary layer meteorology features of the Pearl River Delta, a boundary layer concept model of the Pearl River Delta was built. The concept model consists of four fundamental factors that affect the boundary layer meteorology of the Pearl River Delta and can convincingly explain the reason of the air quality change in the Pearl River Delta. The model can be used to the diffusion capability analysis, the air pollution potential forecasting or haze forecasting, etc. 展开更多
关键词 boundary layer concept model Pearl River Delta
在线阅读 下载PDF
Concept modeling of tapered thin-walled tubes 被引量:1
4
作者 Michael L.DAY 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第1期44-53,共10页
This paper presents a method to create concept models for the tapered thin-walled tubes using beam elements and spring elements.Developed concept tapered beam models with different taper angles and cross sections are ... This paper presents a method to create concept models for the tapered thin-walled tubes using beam elements and spring elements.Developed concept tapered beam models with different taper angles and cross sections are compared with those detailed models through impact analyses.Important crash results are recorded and compared,and the relatively good agreement is achieved between these analyses.Concept modeling steps are illustrated in detail,and a general concept modeling method for such thin-walled tubes is summarized and presented. 展开更多
关键词 Tapered tube concept model Axial crushing Impact analysis Beam element Spring element
原文传递
Effects of health concept model-based detailed behavioral care on mood and quality of life in elderly patients with chronic heart failure 被引量:2
5
作者 Ai-Di Zheng Li-Li Cai Jing Xu 《World Journal of Psychiatry》 SCIE 2023年第7期444-452,共9页
BACKGROUND With the intensification of social aging,the susceptibility of the elderly population to diseases has attracted increasing attention,especially chronic heart failure(CHF)that accounts for a large proportion... BACKGROUND With the intensification of social aging,the susceptibility of the elderly population to diseases has attracted increasing attention,especially chronic heart failure(CHF)that accounts for a large proportion of the elderly.AIM To evaluate the application value of health concept model-based detailed behavioral care in elderly patients with CHF.METHODS This study recruited 116 elderly CHF patients admitted from October 2018 to October 2020 and grouped them according to the nursing care that they received.The elderly patients who underwent health concept model-based detailed behavioral care were included in a study group(SG;n=62),and those who underwent routine detailed behavioral nursing intervention were included as a control group(CG;n=54).Patients’negative emotions(NEs),quality of life(QoL),and nutritional status were assessed using the self-rating anxiety/depression scale(SAS/SDS),the Minnesota Living with Heart Failure Questionnaire(MLHFQ),and the Modified Quantitative Subjective Global Assessment(MQSGA)of nutrition,respectively.Differences in rehabilitation efficiency,NEs,cardiac function(CF)indexes,nutritional status,QoL,and nursing satisfaction were comparatively analyzed.RESULTS A higher response rate was recorded in the SG vs the CG after intervention(P<0.05).After care,the left ventricular ejection fraction was higher while the left ventricular end-diastolic dimension and left ventricular end systolic diameter were lower in the SG compared with the CG(P<0.05).The post-intervention SAS and SDS scores,as well as MQSGA and MLHFQ scores,were also lower in the SG(P<0.05).The SG was also superior to the CG in the overall nursing satisfaction rate(P<0.05).CONCLUSION Health concept model-based detailed behavioral care has high application value in the nursing care of elderly CHF patients,and it can not only effectively enhance rehabilitation efficiency,but also mitigate patients’NEs and improve their CF and QoL. 展开更多
关键词 Chronic heart failure Elderly patients Health concept model Detailed behavioral care Patient mood Quality of life Nursing effect
暂未订购
Concept Model of Ecological Civilization Regulated by Nature,Society and Government 被引量:1
6
作者 GAN Jiang-ying WU Bin 《Asian Agricultural Research》 2011年第9期57-60,共4页
We studied theoretic development of ecological civilization,and put forward the concept model of ecological civilization regulated by nature,society and government.In the construction of ecological civilization,the na... We studied theoretic development of ecological civilization,and put forward the concept model of ecological civilization regulated by nature,society and government.In the construction of ecological civilization,the nature,society and government play different roles and have respective functions.Therefore,we should build a self-regulating network of ecological civilization through natural law,social law,as well as scientific outlook on development. 展开更多
关键词 Ecological civilization Regulating network Scientific outlook on development concept model China
在线阅读 下载PDF
The Transform Method from the Concept Model to the Petri Net Model
7
作者 蒋昌俊 《High Technology Letters》 EI CAS 1997年第1期42-45,共4页
A concept model for the specification of the system is presented in this paper. It includes power graph,resource graph and restriction set. The transformation algorithms from concept model to Petri net model are given... A concept model for the specification of the system is presented in this paper. It includes power graph,resource graph and restriction set. The transformation algorithms from concept model to Petri net model are given respectively. The method is illustrated by an example of the discrete manufacturing system. 展开更多
关键词 DISCRETE CONCURRENT system ESTABLISHMENT model PETRI net concept model specification
在线阅读 下载PDF
Optimized Modeling Method for Unbalanced Data in High-Level Visual Semantic Concept Classification
8
作者 谭励 曹元大 +1 位作者 杨明华 贺巧艳 《Journal of Beijing Institute of Technology》 EI CAS 2009年第2期186-191,共6页
To solve the unbalanced data problems of learning models for semantic concepts, an optimized modeling method based on the posterior probability support vector machine (PPSVM) is presented. A neighborbased posterior ... To solve the unbalanced data problems of learning models for semantic concepts, an optimized modeling method based on the posterior probability support vector machine (PPSVM) is presented. A neighborbased posterior probability estimator for visual concepts is provided. The proposed method has been applied in a high-level visual semantic concept classification system and the experiment results show that it results in enhanced performance over the baseline SVM models, as well as in improved robustness with respect to high-level visual semantic concept classification. 展开更多
关键词 visual concept modeling posterior probability support vector machine unbalanced data
在线阅读 下载PDF
Disturbed state concept as unified constitutive modeling approach 被引量:5
9
作者 Chandrakant S.Desai 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2016年第3期277-293,共17页
A unified constitutive modeling approach is highly desirable to characterize a wide range of engineeringmaterials subjected simultaneously to the effect of a number of factors such as elastic, plastic and creepdeforma... A unified constitutive modeling approach is highly desirable to characterize a wide range of engineeringmaterials subjected simultaneously to the effect of a number of factors such as elastic, plastic and creepdeformations, stress path, volume change, microcracking leading to fracture, failure and softening,stiffening, and mechanical and environmental forces. There are hardly available such unified models. Thedisturbed state concept (DSC) is considered to be a unified approach and is able to provide materialcharacterization for almost all of the above factors. This paper presents a description of the DSC, andstatements for determination of parameters based on triaxial, multiaxial and interface tests. Statementsof DSC and validation at the specimen level and at the boundary value problem levels are also presented.An extensive list of publications by the author and others is provided at the end. The DSC is considered tobe a unique and versatile procedure for modeling behaviors of engineering materials and interfaces. 2016 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. This is an open access article under the CC BY-NC-ND license 展开更多
关键词 Disturbed state concept (DSC)Constitutive model Parameters Soils Interfaces Validations
在线阅读 下载PDF
Hybrid Chinese Information Retrieval Model Based on the Combination of Keyword and Concept 被引量:2
10
作者 樊孝忠 李宏乔 李良富 《Journal of Beijing Institute of Technology》 EI CAS 2003年第S1期120-123,共4页
A hybrid model that is based on the Combination of keywords and concept was put forward. The hybrid model is built on vector space model and probabilistic reasoning network. It not only can exert the advantages of key... A hybrid model that is based on the Combination of keywords and concept was put forward. The hybrid model is built on vector space model and probabilistic reasoning network. It not only can exert the advantages of keywords retrieval and concept retrieval but also can compensate for their shortcomings. Their parameters can be adjusted according to different usage in order to accept the best information retrieval result, and it has been proved by our experiments. 展开更多
关键词 hybrid information retrieval model concept retrieval vector space model probabilistic reasoning network
在线阅读 下载PDF
Concept and evaluation of bay health:the role of numerical model in the Yueqing Bay,China
11
作者 ZHOU Dacheng SUN Zhilin +2 位作者 HUANG Yu HUANG Saihua LI Li 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第8期3-15,共13页
To better evaluate the three-dimensional bay health and predict the dynamic bay health conditions, a concept of numerical bay health was introduced and a method of numerical bay health evaluation(NBHE) was developed... To better evaluate the three-dimensional bay health and predict the dynamic bay health conditions, a concept of numerical bay health was introduced and a method of numerical bay health evaluation(NBHE) was developed.To support the NBHE method, a numerical bay health index(NBHI) system was constructed, which assess the natural and socio-economic effects on the entire bay. Five index groups are combined to formulate the NBHI,including geometry, hydrodynamics and sediment dynamics, bio-ecology, water quality and socio-economy.Each group has different number of indices selected and weighted using AHP method according to their importance. Data were mainly synthesized from a variety of numerical models together with monitoring programs, which provide superior to other approaches in discriminating data integrity and predicting data in future. The NBHE method using NBHI system was applied in the Yueqing Bay during spring tide in April 2007.According to the NBHE results, Sta. A, at the surface level of the estuarine mouth, has a healthy geometry condition, sub-healthy hydrodynamic and sediment dynamic condition, and unhealthy water quality and bioecology conditions. The integrated healthy score at Sta. A indicates its sub-healthy condition. 展开更多
关键词 numerical bay health concept numerical model numerical index system three dimensional evaluation Yueqing Bay
在线阅读 下载PDF
A VISCOPLASTIC MODEL BASED ON NO-YIELD-SURFACE CONCEPT
12
作者 周光泉 程经毅 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1989年第4期337-344,共8页
The elasticjviscoplastic constitutive equation which describes deformation law of metal materials was suggested based on no-yield-surface concept and thermal activation theory of dislocation. The equation which takes ... The elasticjviscoplastic constitutive equation which describes deformation law of metal materials was suggested based on no-yield-surface concept and thermal activation theory of dislocation. The equation which takes account of effects of strain-rate, strain history, strain-rate history, hardening and temperature has stronger physical basis.Comparison of the theoretical prediction with experimental results of mechanical behaviours of Ti under conditions of uniaxial stress and room temperature shows good consistency. 展开更多
关键词 A VISCOPLASTIC model BASED ON NO-YIELD-SURFACE concept
在线阅读 下载PDF
Application of the Static Headland-Bay Beach Concept to a Sandy Beach: A New Elliptical Model
13
作者 LI Bing ZHUANG Zhenye +1 位作者 CAO Lihua DU Fengchao 《Journal of Ocean University of China》 SCIE CAS CSCD 2020年第1期81-89,共9页
The headland-bay beach is one of the most common coastal types in the world.Its morphology reflects the changes that occurred during long-term evolution of the sandy coast.Several headland-bay beach models have been p... The headland-bay beach is one of the most common coastal types in the world.Its morphology reflects the changes that occurred during long-term evolution of the sandy coast.Several headland-bay beach models have been proposed to simulate the coastline’s configuration in equilibrium.In this paper,a new elliptical model is proposed,described,and applied.On the east coast of Laizhou Bay in Shandong Province from Longkou Port to Diaolongzui,four typical headland-bay beaches have developed,and four headland-bay beach models are used in this paper to simulate the morphology of these beaches to assess the applicability of each model.The simulation results of the elliptical model verify that it is applicable to the study area.In addition,the elliptical model is easy to use.Through simulation and field investigations,we concluded that most of the coastal segments in this area will remain in an erosion state,and the human activity has a significant impact on the shoreline’s evolution. 展开更多
关键词 static headland-bay beach concept elliptical model sandy beach coastal erosion east coast of Laizhou Bay
在线阅读 下载PDF
A Maritime Document Knowledge Graph Construction Method Based on Conceptual Proximity Relations
14
作者 Yiwen Lin Tao Yang +3 位作者 Yuqi Shao Meng Yuan Pinghua Hu Chen Li 《Journal of Computer and Communications》 2025年第2期51-67,共17页
The cost and strict input format requirements of GraphRAG make it less efficient for processing large documents. This paper proposes an alternative approach for constructing a knowledge graph (KG) from a PDF document ... The cost and strict input format requirements of GraphRAG make it less efficient for processing large documents. This paper proposes an alternative approach for constructing a knowledge graph (KG) from a PDF document with a focus on simplicity and cost-effectiveness. The process involves splitting the document into chunks, extracting concepts within each chunk using a large language model (LLM), and building relationships based on the proximity of concepts in the same chunk. Unlike traditional named entity recognition (NER), which identifies entities like “Shanghai”, the proposed method identifies concepts, such as “Convenient transportation in Shanghai” which is found to be more meaningful for KG construction. Each edge in the KG represents a relationship between concepts occurring in the same text chunk. The process is computationally inexpensive, leveraging locally set up tools like Mistral 7B openorca instruct and Ollama for model inference, ensuring the entire graph generation process is cost-free. A method of assigning weights to relationships, grouping similar pairs, and summarizing multiple relationships into a single edge with associated weight and relation details is introduced. Additionally, node degrees and communities are calculated for node sizing and coloring. This approach offers a scalable, cost-effective solution for generating meaningful knowledge graphs from large documents, achieving results comparable to GraphRAG while maintaining accessibility for personal machines. 展开更多
关键词 Knowledge Graph Large Language model concept Extraction Cost-Effective Graph Construction
在线阅读 下载PDF
以跨理念模型为框架的微视频延续护理在黄斑水肿患者中的应用
15
作者 韩英 孔晓路 +1 位作者 罗莎 王艳 《齐鲁护理杂志》 2026年第3期118-121,共4页
目的:探讨以跨理念模型为框架的微视频延续护理在黄斑水肿患者中的应用效果。方法:选取2022年6月—2023年6月接受治疗的96例黄斑水肿患者作为受试者,采用随机双盲法分为对照组和观察组各48例,对照组给予常规临床护理,观察组在此基础上... 目的:探讨以跨理念模型为框架的微视频延续护理在黄斑水肿患者中的应用效果。方法:选取2022年6月—2023年6月接受治疗的96例黄斑水肿患者作为受试者,采用随机双盲法分为对照组和观察组各48例,对照组给予常规临床护理,观察组在此基础上给予以跨理念模型为框架的微视频延续护理;比较两组护理前后自我效能感[采用一般自我效能感量表(GSES)]、自护能力[采用自我护理能力测定量表(ESCA)]、心理状态[采用抑郁自评量表(SDS)和焦虑自评量表(SAS)]、生活质量及并发症发生率。结果:护理后,两组GSES、ESCA评分均高于护理前(P<0.05),且观察组均高于对照组(P<0.05,P<0.01);护理后,两组SAS、SDS评分均低于护理前(P<0.05),且观察组均低于对照组(P<0.05,P<0.01);观察组生活质量评分高于对照组(P<0.01),并发症发生率低于对照组(P<0.05)。结论:以跨理念模型为框架的微视频延续护理能有效提高黄斑水肿患者的自我效能感和自护能力,减少焦虑、抑郁等不良情绪的发生,提高其生活质量,降低并发症的发生风险,护理安全性较高。 展开更多
关键词 黄斑水肿 跨理念模型 微视频 延续护理 自我效能感 生活质量
暂未订购
健商理念结合行为互动模式对PCI术后患者的影响
16
作者 李岩 孙娟 +4 位作者 陈虔 单秋菊 王珍珍 荆志敏 杨雪娜 《齐鲁护理杂志》 2026年第4期154-157,共4页
目的:探讨健商(HQ)理念结合行为互动模式对经皮冠状动脉介入治疗(PCI)术后患者的影响。方法:纳入2022年1月—2024年12月接受PCI的128例患者为研究样本。采用随机数字表法分为对照组和观察组各64例,对照组实施常规护理,观察组实施HQ理念... 目的:探讨健商(HQ)理念结合行为互动模式对经皮冠状动脉介入治疗(PCI)术后患者的影响。方法:纳入2022年1月—2024年12月接受PCI的128例患者为研究样本。采用随机数字表法分为对照组和观察组各64例,对照组实施常规护理,观察组实施HQ理念结合行为互动模式干预。比较两组干预前后希望水平[采用Herth希望量表(HHI)]、锻炼依从性(采用自制心血管病患者锻炼依从性量表)、生活质量[采用西雅图心绞痛量表(SAQ)]、并发症发生情况。结果:干预后,两组HHI、锻炼依从性评分、SAQ各维度评分及总分均高于干预前(P<0.05),且观察组高于对照组(P<0.01);观察组并发症总发生率低于对照组(P<0.01)。结论:将HQ理念结合行为互动模式应用于PCI术后患者,可提高患者希望水平及锻炼依从性,改善生活质量,降低并发症发生率。 展开更多
关键词 健商理念 行为互动模式 经皮冠状动脉介入治疗 希望水平 锻炼依从性
暂未订购
基于OBE理念的BOPPPS教学模式在西医院校中医学教学中的应用——以脏腑辨证为例
17
作者 李凯 李展 +1 位作者 冼秋花 吕军影 《卫生职业教育》 2026年第4期55-58,共4页
目的 探讨成果导向教育(OBE)理念结合BOPPPS教学模式在西医院校中医学脏腑辨证教学中的应用效果。方法选取广西医科大学2021级临床医学本科专业3个班级的学生作为对照组(n=165),采用传统教学模式;选取2022级临床医学本科专业3个班级的... 目的 探讨成果导向教育(OBE)理念结合BOPPPS教学模式在西医院校中医学脏腑辨证教学中的应用效果。方法选取广西医科大学2021级临床医学本科专业3个班级的学生作为对照组(n=165),采用传统教学模式;选取2022级临床医学本科专业3个班级的学生作为观察组(n=163),采用基于OBE理念的BOPPPS教学模式。通过理论知识和临床实践考核以及自主学习能力、教学效果评价及满意度问卷调查进行综合评估。结果 观察组学生的理论知识与临床实践考核成绩均高于对照组(P<0.05),自主学习能力各因子得分均高于对照组(P<0.05),对本组所采用教学方法的教学内容、教学方法和教学效果的评分和总分均明显高于对照组(P<0.05),教学满意度明显高于对照组(P<0.05)。结论 基于OBE理念的BOPPPS教学模式能有效提升学生的理论知识与临床实践考核成绩、自主学习能力和教学满意度,提高西医院校中医学课程教学质量,值得推广应用。 展开更多
关键词 OBE理念 BOPPPS教学模式 西医院校 中医学 脏腑辨证
在线阅读 下载PDF
基于OBE理念融合PAD教学模式在《医用高等数学》中的探索与实践
18
作者 陈晨 朱乐玫 邴萍萍 《教育教学研究前沿》 2026年第2期87-89,共3页
《医用高等数学》中涵盖导数与微分、函数与极限、微分方程、定积分、不定积分等内容,教材是运用练习题、理论例题和案例修订帮助学生强化实践的方式,开展数字化教材建设的。若教师采用传统模式教学,可能造成医学与数学理论知识实际应... 《医用高等数学》中涵盖导数与微分、函数与极限、微分方程、定积分、不定积分等内容,教材是运用练习题、理论例题和案例修订帮助学生强化实践的方式,开展数字化教材建设的。若教师采用传统模式教学,可能造成医学与数学理论知识实际应用场景之间的脱节,增加学生的学习难度,所以教师应增加教学活动中的数字化载体,以OBE理念融合PAD教学模式开展教学,引导学生用数学去合理解决医学领域问题。基于此,本文结合实际思考,简要分析OBE理念融合PAD教学模式在《医用高等数学》中的价值,重点阐述OBE理念融合PAD教学模式在《医用高等数学》中的探索与实践。旨在为学生的全面发展提供支持。 展开更多
关键词 OBE理念 融合 PAD教学模式 《医用高等数学》 探索与实践
暂未订购
Numerical Simulation of Oxy-coal Combustion for a Swirl Burner with EDC Model 被引量:6
19
作者 崔凯 刘冰 +3 位作者 吴玉新 杨海瑞 吕俊复 张海 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第2期193-201,共9页
The characteristics of oxy-coal combustion for a swirl burner with a specially designed preheating chamber are studied numerically. In order to increase the accuracy in the prediction of flame temperature and igni- ti... The characteristics of oxy-coal combustion for a swirl burner with a specially designed preheating chamber are studied numerically. In order to increase the accuracy in the prediction of flame temperature and igni- tion position, eddy dissipation concept (EDC) model with a skeletal chemical reaction mechanism was adopted to describe the combustion of volatile matter. Simulation was conducted under six oxidant stream conditions with dif- ferent OjN2/CO2 molar ratios: 21/79/0, 30/70/0, 50/50/0, 21/0/79, 30/0/70 and 50/0/50. Results showed that 02 en- richment in the primary oxidant stream is in favor of combustion stabilization, acceleration of ignition and increase of maximum flame temperature, while the full substitution of N2 by CO2 in the oxidant stream delays ignition and decreases the maximum flame temperature. However, the overall flow field and flame shapes in these cases are very similar at the same flow rate of the primary oxidant stream. Combustion characteristics of the air-coal is similar to that of the oxy-coal with 30% 02 and 70% CO2 in the oxidant stream, indicating that the rear condition is suitable for retrofitting an air-coal fired boiler to an oxy-coal one. The swirl burner with a specially designed preheating chamber can increase flame temperature, accelerate ignition and enhance burning intensity of pulverized coal under oxy-coal combustion. Also, qualitative experimental validation indicated the burner can reduce the overall NOx emission under certain 02 enrichment and oxy-coal combustion conditions against the air-coal combustion. 展开更多
关键词 oxy-coal eddy dissipation concept model COAL swirl burner
在线阅读 下载PDF
The research on the remote sensing's information tree model of the Nansha coral islets and reef's spatial structure 被引量:1
20
作者 Liu Baoyin Wang Yanfeng and Hao Qingxiang(First institute of beanography, State  ̄ic Administration, Qingdso 266003, China Naming University, Naming 210008, China) 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1996年第3期331-344,共14页
Based on the Nansha coral islets and reef's time-space attributes,and the intension and extension of the remote sensing information, the concept model and concept system of coral islets and reef are proposed.Then ... Based on the Nansha coral islets and reef's time-space attributes,and the intension and extension of the remote sensing information, the concept model and concept system of coral islets and reef are proposed.Then twin-tree remote sensing information model for different kinds of reef is constructed by using abstracted islets and reef's primitive, and the structure recognition system for coral islets and reef type is developed. 展开更多
关键词 Nansha Islands coral reefs remote sensing information tree concept model PRIMITIVE
在线阅读 下载PDF
上一页 1 2 118 下一页 到第
使用帮助 返回顶部