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基于相似准则的林业无土栽培基质混合分析
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作者 沈嵘枫 钟文斌 +3 位作者 王沅栋 黄俊疆 张文悦 杨诗嘉 《森林工程》 北大核心 2025年第5期1034-1041,共8页
针对无土栽培基质生产过程中基质混合不充分和采用离散元法时因模型过大、颗粒数过多而导致仿真结果不精确的问题,通过建立相似理论搅拌模型,利用赫兹-明德林(无滑移)模型(Hertz-Mindlin(no slip))建立肥料与土壤颗粒仿真模型,对影响混... 针对无土栽培基质生产过程中基质混合不充分和采用离散元法时因模型过大、颗粒数过多而导致仿真结果不精确的问题,通过建立相似理论搅拌模型,利用赫兹-明德林(无滑移)模型(Hertz-Mindlin(no slip))建立肥料与土壤颗粒仿真模型,对影响混合器搅拌均匀性和效率的放料方式、搅拌式混合器叶片间距和搅拌器转速3个变量因素进行离散元仿真分析。结果表明,相似理论搅拌模型可用于仿真模型的缩放,达到减少计算量,提高仿真精度的效果;采用平铺的放料方式,由于上层颗粒会在重力的作用下加速颗粒间的混合,混合效果更佳;相似模型中叶片间较佳间距为20 mm;叶片转速在50 r/min时搅拌混合效果和经济性最佳;与人工搅拌相比,搅拌式混合器大大提高了混合效率和效果,且可以避免出现盲区。仿真分析结果可为搅拌式混合器的设计与优化提供理论参考。 展开更多
关键词 育苗基质 搅拌装置 相似准则 离散元分析 Event driven execution manager(EDEM)离散元仿真软件
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Planning,monitoring and replanning techniques for handling abnormity in HTN-based planning and execution
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作者 KANG Kai CHENG Kai +2 位作者 SHAO Tianhao ZHANG Hongjun ZHANG Ke 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第5期1264-1275,共12页
A framework that integrates planning,monitoring and replanning techniques is proposed.It can devise the best solution based on the current state according to specific objectives and properly deal with the influence of... A framework that integrates planning,monitoring and replanning techniques is proposed.It can devise the best solution based on the current state according to specific objectives and properly deal with the influence of abnormity on the plan execution.The framework consists of three parts:the hierarchical task network(HTN)planner based on Monte Carlo tree search(MCTS),hybrid plan monitoring based on forward and backward and norm-based replanning method selection.The HTN planner based on MCTS selects the optimal method for HTN compound task through pre-exploration.Based on specific objectives,it can identify the best solution to the current problem.The hybrid plan monitoring has the capability to detect the influence of abnormity on the effect of an executed action and the premise of an unexecuted action,thus trigger the replanning.The norm-based replanning selection method can measure the difference between the expected state and the actual state,and then select the best replanning algorithm.The experimental results reveal that our method can effectively deal with the influence of abnormity on the implementation of the plan and achieve the target task in an optimal way. 展开更多
关键词 hierarchical task network Monte carlo tree search(MCTS) PLANNING EXECUTION abnormity
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对“行政”概念的历史考察 被引量:5
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作者 张康之 张桐 《社会科学研究》 CSSCI 北大核心 2010年第1期51-61,共11页
"行政"一词有着悠久的历史,经历了一个漫长的历史演化过程,在不同的时期以及不同的地区,有着不同的用法与含义。在古代希腊和罗马,人们谈论行政问题时,所关注的是公职或行政官职。到了中世纪,马西利乌斯开始关注到"行政... "行政"一词有着悠久的历史,经历了一个漫长的历史演化过程,在不同的时期以及不同的地区,有着不同的用法与含义。在古代希腊和罗马,人们谈论行政问题时,所关注的是公职或行政官职。到了中世纪,马西利乌斯开始关注到"行政职能"的问题,从而引发人们对法律与行政关系的思考,并促成了"立法与执行"的二分。沿着"立法与执行"二分的传统前行,就走到了孟德斯鸠的三权分立。在三权分立的理论确立起来之后,行政权虽然被作为一项单列出来的权力而加以认识,但是,它依然属于政治权力的范畴。威尔逊的贡献则是把抽象意义上的"executive power"与具体行动层面上的"administration"加以区分,形成了"政治—行政二分"原则,并建立了行政学。 展开更多
关键词 行政 执行 executive ADMINISTRATION
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基于供应链环境下的执行信息管理系统 被引量:4
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作者 林勇 马士华 《计算机工程与应用》 CSCD 北大核心 2001年第14期159-161,共3页
主要提出了基于供应链环境的执行信息管理系统的结构框架模型,以及具体的系统功能结构图,并阐述了系统所采用的信息支持技术,最后总结了系统的特点。
关键词 供应链 决策支持 执行信息管理系统(executive INFORMATION MANAGEMENT System EIMS)
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面向WCET估计的Cache分析研究综述 被引量:10
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作者 吕鸣松 关楠 王义 《软件学报》 EI CSCD 北大核心 2014年第2期179-199,共21页
实时系统时间分析的首要任务是估计程序的最坏情况执行时间(worst-case execution time,简称WCET).程序的WCET通常受到硬件体系结构的影响,Cache则是其中最为突出的因素之一.对面向WCET计算的Cache分析研究进行了综述,介绍了经典Cache... 实时系统时间分析的首要任务是估计程序的最坏情况执行时间(worst-case execution time,简称WCET).程序的WCET通常受到硬件体系结构的影响,Cache则是其中最为突出的因素之一.对面向WCET计算的Cache分析研究进行了综述,介绍了经典Cache分析框架与Cache分析核心技术,并从循环结构分析、数据Cache分析、多级Cache分析、多核共享Cache分析、非LRU替换策略分析等角度介绍了Cache分析在不同维度上的研究问题与主要挑战,总结了现有技术的优缺点,展望了Cache分析研究的未来发展方向. 展开更多
关键词 实时系统 WCET(worst-case EXECUTION time) Cache分析 时间分析 抽象解释
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一种基于CPN的BPEL异常处理逻辑的开发方法 被引量:2
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作者 管华 应时 +2 位作者 贾向阳 蒋曹清 王一兵 《计算机科学》 CSCD 北大核心 2013年第1期150-156,共7页
针对WS-BPEL在面向服务软件异常处理方面不够完善的问题,提出了一种基于着色Petri网描述的BPEL异常处理逻辑开发方法。该方法利用着色Petri网(CPN)形式化地描述BPEL的异常处理机制,建立BPEL的异常处理CPN模型,指导对BPEL的异常处理逻辑... 针对WS-BPEL在面向服务软件异常处理方面不够完善的问题,提出了一种基于着色Petri网描述的BPEL异常处理逻辑开发方法。该方法利用着色Petri网(CPN)形式化地描述BPEL的异常处理机制,建立BPEL的异常处理CPN模型,指导对BPEL的异常处理逻辑开发,并依据此建模思想,提出了一个BPEL的异常处理CPN模型的转换工具,用以实现将异常处理的BPEL着色Petri网模型转换成对应的带异常处理的BPEL代码。该工具可在输入的原始的没有异常处理功能的BPEL代码基础上,通过动态地添加BPEL的异常处理语言成份,形成带有异常处理功能的BPEL流程。最后通过引入供应商流程案例,阐述了该方法的具体使用过程。 展开更多
关键词 着色PETRI网 BPEL(Business Process EXECUTION Language) 异常处理
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基于WCET分析的实时系统轨迹获取技术 被引量:2
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作者 王馨 姬孟洛 +1 位作者 王戟 齐治昌 《软件学报》 EI CSCD 北大核心 2006年第5期1232-1240,共9页
时序约束是判断实时系统运行是否正确的重要规约.为了减小测试时由于对系统进行插装而产生的对实时系统行为的影响,提出了一种混合式监控方法.它对系统的时间干扰比纯软件方式小,并支持对系统的完全测试.此外,还提出一种基于WCET(worst-... 时序约束是判断实时系统运行是否正确的重要规约.为了减小测试时由于对系统进行插装而产生的对实时系统行为的影响,提出了一种混合式监控方法.它对系统的时间干扰比纯软件方式小,并支持对系统的完全测试.此外,还提出一种基于WCET(worst-caseexecutiontime)分析技术的目标系统时间补偿方法,在精确地计算插入断言对目标系统的时间影响基础上,给出时间补偿. 展开更多
关键词 实时系统 测试预言 WCET(worst-case EXECUTION time)分析 程序监控
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基于Petri网的某型导弹单发任务完成概率仿真 被引量:2
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作者 韩雪魁 张柳 史俊斌 《科学技术与工程》 2007年第10期2458-2461,共4页
任务成功概率是任务成功性的概率度量,指在规定的任务剖面内,产品能完成规定任务的概率。使用基于Petri网原理的ExSpect仿真软件,对单发导弹的任务流程进行了模拟,首先构建基本任务的仿真模型,在此基础上针对导弹整体任务流程构建了仿... 任务成功概率是任务成功性的概率度量,指在规定的任务剖面内,产品能完成规定任务的概率。使用基于Petri网原理的ExSpect仿真软件,对单发导弹的任务流程进行了模拟,首先构建基本任务的仿真模型,在此基础上针对导弹整体任务流程构建了仿真模型,并计算其任务完成概率,最后通过应用实例验证模型的可行性。 展开更多
关键词 PETRI网 任务完成概率ExSpect(Executable Specification tool) 仿真模型
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MATLAB与C混合编程技术在A/D性能测试中的应用 被引量:1
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作者 王益民 《现代雷达》 CSCD 北大核心 2015年第6期81-84,共4页
讨论了MATLAB及C混合编程的优点,介绍了C-MEX的实现原理,并结合A/D性能测试设备的开发,在MATLAB环境中编写VME总线平台下硬件读写程序,解决了MATLAB不能直接访问底层硬件的问题,给出了软件设计流程。结果表明:该方法提高了系统实时性能... 讨论了MATLAB及C混合编程的优点,介绍了C-MEX的实现原理,并结合A/D性能测试设备的开发,在MATLAB环境中编写VME总线平台下硬件读写程序,解决了MATLAB不能直接访问底层硬件的问题,给出了软件设计流程。结果表明:该方法提高了系统实时性能,简化了编程步骤,较好地发挥了C与MATLAB软件的整体优势。 展开更多
关键词 MATLAB软件 混合编程 MATLAB Executable混合编程
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WORLD MEWS IN BRIH (May 1-15, 1993)
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《国际展望》 北大核心 1993年第10期32-32,共1页
Sri Lankan President Premodasa was killed by a suicide bomber in a massive blast at a May Day rally. On May 7, Prime Minister Dingiri Banda Wijetunge was elected Sri Lanka’s new executive president by the Parliament.
关键词 MINISTER president rally executive killed MAY 1-15 massive blast SECRETARY DOLLAR
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如何实现教育创新与企业目标的紧密结合(Ⅰ)——哥伦比亚大学商学院总裁部“解决问题过程”教学实践
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作者 William Klepper 李富明 《技术经济与管理研究》 2003年第6期9-12,共4页
关键词 教育创新 企业目标 哥伦比亚大学商学院 总裁培训部 索尼移动通信公司 Sony 战略学 business objectives EDUCATIONAL INITIATIVES COLUMBIA executive Education Vision
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Distributed tasks-platforms scheduling method to holonic-C2 organization 被引量:3
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作者 WANG Xun YAO Peiyang +2 位作者 ZHANG Jieyong WAN Lujun JIA Fangchao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第1期110-120,共11页
To solve the problem of distributed tasks-platforms scheduling in holonic command and control(C2) organization,the basic elements of the organization are analyzed firstly and the formal description of organizational e... To solve the problem of distributed tasks-platforms scheduling in holonic command and control(C2) organization,the basic elements of the organization are analyzed firstly and the formal description of organizational elements and structure is provided. Based on the improvement of task execution quality,a single task resource scheduling model is established and the solving method based on the m-best algorithm is proposed. For the problem of tactical decision-holon cannot handle tasks with low priority effectively, a distributed resource scheduling collaboration mechanism based on platform pricing and a platform exchange mechanism based on resource capacities are designed. Finally,a series of experiments are designed to prove the effectiveness of these methods. The results show that the proposed distributed scheduling methods can realize the effective balance of platform resources. 展开更多
关键词 COMMAND and control (C2) decision-holon distributed TASK allocation TASK EXECUTION quality platform PRICE order optimization.
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Event-driven process execution model for process virtual machine 被引量:3
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作者 WU Dong-yao WEI Jun GAO Chu-shu DOU Wen-shen 《计算机集成制造系统》 EI CSCD 北大核心 2012年第8期1675-1685,共11页
Current orchestration and choreography process engines only serve with dedicate process languages.To solve these problems,an Event-driven Process Execution Model(EPEM) was developed.Formalization and mapping principle... Current orchestration and choreography process engines only serve with dedicate process languages.To solve these problems,an Event-driven Process Execution Model(EPEM) was developed.Formalization and mapping principles of the model were presented to guarantee the correctness and efficiency for process transformation.As a case study,the EPEM descriptions of Web Services Business Process Execution Language(WS-BPEL) were represented and a Process Virtual Machine(PVM)-OncePVM was implemented in compliance with the EPEM. 展开更多
关键词 business process modeling event-driven architecture process virtual machine service orchestration process execution language
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An executable modeling and analyzing approach to C4ISR architecture 被引量:3
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作者 HE Hongyue ZHU Weixing +1 位作者 LI Ruiyang DENG Qiaoyu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第1期109-117,共9页
To analyze the behavioral model of the command,control,communication,computer,intelligence,surveillance,reconnaissance(C4ISR)architecture,we propose an executable modeling and analyzing approach to it.First,the meta c... To analyze the behavioral model of the command,control,communication,computer,intelligence,surveillance,reconnaissance(C4ISR)architecture,we propose an executable modeling and analyzing approach to it.First,the meta concept model of the C4ISR architecture is introduced.According to the meta concept model,we construct the executable meta models of the C4ISR architecture by extending the meta models of fUML.Then,we define the concrete syntax and executable activity algebra(EAA)semantics for executable models.The semantics functions are introduced to translating the syntax description of executable models into the item of EAA.To support the execution of models,we propose the executable rules which are the structural operational semantics of EAA.Finally,an area air defense of the C4ISR system is used to illustrate the feasibility of the approach. 展开更多
关键词 COMMAND control communication computer INTELLIGENCE SURVEILLANCE reconnaissance(C4ISR)architecture meta model executable model algebraic semantics
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An executable framework for modeling and validating cooperative capability requirements in emergency response system 被引量:1
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作者 CHAI Lei WANG Zhixue +2 位作者 HE Ming HE Hongyue YU Minggang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2021年第4期889-906,共18页
As the scale of current systems become larger and larger and their complexity is increasing gradually,research on executable models in the design phase becomes significantly important as it is helpful to simulate the ... As the scale of current systems become larger and larger and their complexity is increasing gradually,research on executable models in the design phase becomes significantly important as it is helpful to simulate the execution process and capture defects of a system in advance.Meanwhile,the capability of a system becomes so important that stakeholders tend to emphasize their capability requirements when developing a system.To deal with the lack of official specifications and the fundamental theory basis for capability requirement,we propose a cooperative capability requirements(CCR)meta-model as a theory basis for researchers to refer to in this research domain,in which we provide detailed definition of the CCR concepts,associations and rules.Moreover,we also propose an executable framework,which may enable modelers to simulate the execution process of a system in advance and do well in filling the inconsistency and semantic gaps between stakeholders’requirements and their models.The primary working mechanism of the framework is to transform the Alf activity meta-model into the communicating sequential process(CSP)process meta-model based on some mapping rules,after which the internal communication mechanism between process nodes is designed to smooth the execution of behaviors in a CSP system.Moreover,a validation method is utilized to check the correctness and consistency of the models,and a self-fixing mechanism is used to fix the errors and warnings captured during the validation process automatically.Finally,a validation report is generated and fed back to the modelers for system optimization. 展开更多
关键词 executable model capability requirement consistency validation Alf EPSILON
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State Modelling and Simultaneous Control of Discrete Part Manufacturing Product Transformation Processes and Resource Allocation
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作者 Hans Holm 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期251-252,共2页
As competition in the market for discrete part prod uc ts gets harder and harder the requirements for extreme manufacturing operati on efficiencies get increasingly accentuated. Therefore requirements for well behaved... As competition in the market for discrete part prod uc ts gets harder and harder the requirements for extreme manufacturing operati on efficiencies get increasingly accentuated. Therefore requirements for well behaved manufacturing operation control get more and more significant. The purpose of the paper is to establish a framework for development of formal m ethods for design of systems for simultaneous control of continuous manufacturin g task processes and resource allocation of discrete part manufacturing. In the paper states which are needed for feedback control of continuous manufact uring task processes are defined and an example is presented. States which are necessary for feedback control of distribution of manufacturing resources are defined. The definition is based on the states defined for feedba ck control of the continuous processes of discrete part manufacturing tasks. An exemple is presented. Based on use of the state variables two types of equations are described, the pu rpose of which it is to represent the constraints to which control of the manufa cturing system is subject. Characteristic instances of the equations are presen ted. Methods for design of systems which can control continuous tasks are presented. Methods for design of systems which can control resource allocation are presente d. Methods for design of systems which can simultaneously control continuous tas k processes and resource allocation as the resource allocation is subject to con tinuos task execution constraints are presented. 展开更多
关键词 Transformation ALLOCATION COMPETITION SIMULTANEOUS behaved extreme FORMAL constraints EXECUTION
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Modeling of Agile Manufacturing Execution Systems with an Agent-based Approach
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作者 LI Shu-xia, RAO Yun-qing, LI Pei-gen (Intelligent Manufacturing Laboratory, School of Mechanical Science & Engineering, Huazhong University of Science & Technology, Wuhan 430074, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期20-,共1页
Agile manufacturing execution systems (AMES) are used to help manufacturers optimize shop floor production in an agile way. And the modeling of AMES is the key issue of realizing AMES. This paper presents an agent-bas... Agile manufacturing execution systems (AMES) are used to help manufacturers optimize shop floor production in an agile way. And the modeling of AMES is the key issue of realizing AMES. This paper presents an agent-based approach to AMES modeling. Firstly, the characteristics of AMES and its requirements on modeling are discussed. Secondly, a comparative analysis of modeling methods is carried out, and AMES modeling using an agent-based approach is put forward. Agent-based modeling method not only inherit the favorable features of traditional object-oriented modeling method such as data encapsulation, modularity and so on, but also has the ability to construct intelligent, rational and autonomous agent which can cooperate together to realize the goal of agile operation. A general agent architecture used in AMES modeling is described. Under this architecture, an agent can be divided into domain-independent components and domain-specific components which helps solve problems such as information overload, incomplete information handling and soft decision-making. Furthermore, an AMES model using four types of agents, i.e., interface agent, information agent, resource agent and management agent, is established. Thirdly, a snapshot of AMES model is provided in the case study. Especially, an agent-based cooperating process of task scheduling in AMES is illustrated in detail. Finally, the advantages and disadvantages of this modeling approach are discussed as well. 展开更多
关键词 agile manufacturing execution system (AMES) MODELING AGENT
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基于Pro/E的大型斜床身数控车床的程序设计
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作者 孟国兴 《制造技术与机床》 CSCD 北大核心 2010年第3期66-71,共6页
以DL50大型数控车床为例,详细介绍了装配的参数化及程序设计方法和技巧。
关键词 公称参数 程序设计 条件语句 EXECUTE语句
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英语中几组易混淆的形容词辩异
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作者 雷志敏 《湖南师范大学教育科学学报》 1994年第1期64-65,共2页
英语中有些形容词因源于同一动词或名词,拼写有些相似,但发音及意义不同,有时候很容易混淆,往往导致用法及理解方面的错误。现汇集几组举例如下。 1、regrettable与regretful regrettable意为“令人遗憾的,可惜的”,只能用来修饰事物。 ... 英语中有些形容词因源于同一动词或名词,拼写有些相似,但发音及意义不同,有时候很容易混淆,往往导致用法及理解方面的错误。现汇集几组举例如下。 1、regrettable与regretful regrettable意为“令人遗憾的,可惜的”,只能用来修饰事物。 例:It is regrettable that they have leftthe city already.很遗憾他们已经离开这个城市。 展开更多
关键词 形容词 英语 understanding desirable 介词 可信赖的人 EXECUTION SOMETHING 复数名词 英国小说
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′S所有格与of结构
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作者 成善祯 《高校教育管理》 1990年第3期61-66,共6页
现代英语中由′s和表示无生命概念名词构成的′s所有格结构与日俱增,大有与of结构争雄天下之势。国内外语言学家们纷纷就′s结构的崛起及其发展变化之趋势各抒已见。有些学者指出用′s结构取代of结构的倾向十分明显,特别是在美国英语中... 现代英语中由′s和表示无生命概念名词构成的′s所有格结构与日俱增,大有与of结构争雄天下之势。国内外语言学家们纷纷就′s结构的崛起及其发展变化之趋势各抒已见。有些学者指出用′s结构取代of结构的倾向十分明显,特别是在美国英语中,几乎绝大多数名词都可以用′s手段表示领属关系”。“当′s所有格与of所有格,在含义上完全相同时,′s所有格正在迅速替代of所有格。现在′s所有格几乎可以与任何名词相搭配。”′s所有格是否真正可与任何名词相搭配,有没有不尽然的情况?′s所有格替代of结构是否带有一定的先决条件?此两种结构之间是否存在某些语义上的差异?′s与名词搭配使用时是否受语言的某些内在规律的支配?笔者现就上述问题谈谈自己的看法。 展开更多
关键词 名词所有格 of结构 名词中心词 个体名词 物质名词 介宾 相互替换 EXECUTION 限定词 宾语
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