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Exact analytical solution to three-dimensional phase change heat transfer problems in biological tissues subject to freezing
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作者 李方方 刘静 乐恺 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2009年第1期63-72,共10页
Analytically solving a three-dimensional (3-D) bioheat transfer problem with phase change during a freezing process is extremely difficult but theoretically important. The moving heat source model and the Green func... Analytically solving a three-dimensional (3-D) bioheat transfer problem with phase change during a freezing process is extremely difficult but theoretically important. The moving heat source model and the Green function method are introduced to deal with the cryopreservation process of in vitro biomaterials. Exact solutions for the 3-D temperature transients of tissues under various boundary conditions, such as totally convective cooling, totally fixed temperature cooling and a hybrid between them on tissue surfaces, are obtained. Furthermore, the cryosurgical process in living tissues subject to freezing by a single or multiple cryoprobes is also analytically solved. A closed-form analytical solution to the bioheat phase change process is derived by considering contributions from blood perfusion heat transfer, metabolic heat generation, and heat sink of a cryoprobe. The present method is expected to have significant value for analytically solving complex bioheat transfer problems with phase change. 展开更多
关键词 three-dimensional phase change heat transfer problem CRYOsURGERY CRYOPREsERVATION moving heat source model bioheat transfer Green's function analytical solution
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Discourse Analysis of the Belt and Road Initiative From the Perspective of Central Asian Countries: A Case Study of the Republic of Kazakhstan
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作者 CHEN Jia LIU Shumin +1 位作者 FU Da’an SHAO Di 《Journalism and Mass Communication》 2024年第2期96-100,共5页
This study employs Norman Fairclough’s Critical Discourse Analysis(CDA)three-dimensional model,using the Republic of Kazakhstan as a case study,to delve into the discourse construction of China’s Belt and Road Initi... This study employs Norman Fairclough’s Critical Discourse Analysis(CDA)three-dimensional model,using the Republic of Kazakhstan as a case study,to delve into the discourse construction of China’s Belt and Road Initiative(BRI)in Central Asian countries.Through detailed analysis of policy documents,media reports,and public discussions in Central Asian countries,this paper reveals how the BRI constructs specific social practices,discourse events,and textual meanings within these nations.The findings indicate that through this global development strategy,China has not only strengthened its economic ties with Central Asian countries but has also exerted profound influences on political,cultural,and social levels. 展开更多
关键词 Belt and Road Initiative Central Asian countries discourse analysis Norman Fairclough’s three-dimensional model
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The Atom Model of Helium and of Neon Based on the Theorem of Niels Bohr 被引量:2
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作者 Thomas Allmendinger 《Journal of Applied Mathematics and Physics》 2018年第6期1290-1300,共11页
In a previous, primary treatise of the author the mathematical description of electron trajectories in the excited states of the H-atom could be demonstrated, starting from Bohr’s original model but modifying it thre... In a previous, primary treatise of the author the mathematical description of electron trajectories in the excited states of the H-atom could be demonstrated, starting from Bohr’s original model but modifying it three dimensionally. In a subsequent treatise, Bohr’s theorem of an unalterable angular momentum h/2π, determining the ground state of the H-atom, was revealed as an inducement by the—unalterable—electron spin. Starting from this presumption, a model of the H2-molecule could be created which exhibits well-defined electron trajectories, and which enabled computing the bond length precisely. In the present treatise, Bohr’s theorem is adapted to the atom models of helium and of neon. But while this was feasible exactly in the case of helium, the neon atom turned out to be too complex for a mathematical modelling. Nevertheless, a rough ball-and-stick model can be presented, assuming electron rings instead of electron clouds, which in the outer shell are orientated as a tetrahedron. It entails the principal statement that the neon atom does not represent a static construction with constant electron distances and velocities, but a pulsating dynamic one with permanently changing internal distances. Thus, the helium atom marks the limit for precisely describing an atom, whereby at and under this limit such a precise description is feasible, being also demonstrated in the author’s previous work. This contradicts the conventional quantum mechanical theory which claims that such a—locally and temporally—precise description of any atom or molecule structure is generally not possible, also not for the H2-molecule, and not even for the H-atom. 展开更多
关键词 Modified BOHR model Electron-Trajectories ELECTRON-sPIN three-dimensional Atom-models Confutation of Heisenberg’s Uncertainty-Principle
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Unraveling pathological mechanisms in neurological disorders:the impact of cell-based and organoid models
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作者 Jake Langlie Rahul Mittal +5 位作者 Ariel Finberg Nathalie B.Bencie Jeenu Mittal Hossein Omidian Yadollah Omidi Adrien A.Eshraghi 《Neural Regeneration Research》 SCIE CAS CSCD 2022年第10期2131-2140,共10页
Cell-based models are a promising tool in deciphering the molecular mechanisms underlying the pathogenesis of neurological disorders as well as aiding in the discovery and development of future drug therapies.The grea... Cell-based models are a promising tool in deciphering the molecular mechanisms underlying the pathogenesis of neurological disorders as well as aiding in the discovery and development of future drug therapies.The greatest challenge is creating cell-based models that encapsulate the vast phenotypic presentations as well as the underlying genotypic etiology of these conditions.In this article,we discuss the recent advancements in cell-based models for understanding the pathophysiology of neurological disorders.We reviewed studies discussing the progression of cell-based models to the advancement of three-dimensional models and organoids that provide a more accurate model of the pathophysiology of neurological disorders in vivo.The better we understand how to create more precise models of the neurological system,the sooner we will be able to create patient-specific models and large libraries of these neurological disorders.While three-dimensional models can be used to discover the linking factors to connect the varying phenotypes,such models will also help to understand the early pathophysiology of these neurological disorders and how they are affected by their environment.The three-dimensional cell models will allow us to create more specific treatments and uncover potentially preventative measures in neurological disorders such as autism spectrum disorder,Parkinson’s disease,Alzheimer’s disease,and amyotrophic lateral sclerosis. 展开更多
关键词 Alzheimer’s disease amyotrophic lateral sclerosis autism spectrum disorder cell-based model central nervous system induced pluripotent stem cells mesenchymal stem cells organoid model organ-on-a-chip Parkinson’s disease three-dimensional model
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Hall Effects on Unsteady MHD Three Dimensional Flow through a Porous Medium in a Rotating Parallel Plate Channel with Effect of Inclined Magnetic Field
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作者 P. Sulochana 《American Journal of Computational Mathematics》 2014年第5期396-405,共10页
In this paper, we make an initial value investigation of the unsteady flow of incompressible viscous fluid between two rigid non-conducting rotating parallel plates bounded by a porous medium under the influence of a ... In this paper, we make an initial value investigation of the unsteady flow of incompressible viscous fluid between two rigid non-conducting rotating parallel plates bounded by a porous medium under the influence of a uniform magnetic field of strength H0 inclined at an angle of inclination α with normal to the boundaries taking hall current into account. The perturbations are created by a constant pressure gradient along the plates in addition to the non-torsional oscillations of the upper plate while the lower plate is at rest. The flow in the porous medium is governed by the Brinkman’s equations. The exact solution of the velocity in the porous medium consists of steady state and transient state. The time required for the transient state to decay is evaluated in detail and the ultimate quasi-steady state solution has been derived analytically. Its behaviour is computationally discussed with reference to the various governing parameters. The shear stresses on the boundaries are also obtained analytically and their behaviour is computationally discussed. 展开更多
关键词 hall Effects UNsTEADY ROTATING FLOWs three-dimensional FLOWs Parallel Plate Channels INCOMPREssIBLE VIsCOUs Fluids Brinkman’s model
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数据跨境流动安全管理协同研究 被引量:1
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作者 牛晓宏 夏童 《现代情报》 北大核心 2024年第8期39-50,共12页
[目的/意义]数据跨境流动推动了数字经济发展和国际交流合作,探索数据跨境流动安全管理协同问题,有利于维护数据安全和国家安全,促进数据利用体系与能力建设。[方法/过程]运用Nvivo软件,分析我国数据跨境流动安全管理协同存在的问题与... [目的/意义]数据跨境流动推动了数字经济发展和国际交流合作,探索数据跨境流动安全管理协同问题,有利于维护数据安全和国家安全,促进数据利用体系与能力建设。[方法/过程]运用Nvivo软件,分析我国数据跨境流动安全管理协同存在的问题与产生的原因,基于协同理论和霍尔三维模型,构建数据跨境流动安全管理协同三维模型。[结果/结论]构建以组织协同机制、法制协同机制和资源协同机制3个子机制构成的数据跨境流动安全管理协同机制,并从知识共享、技术实力、文化环境3方面提出数据跨境流动安全管理协同机制运行保障措施,实现数据跨境流动安全管理协同效果。 展开更多
关键词 数据跨境流动 数据安全 安全管理 协同理论 协同机制 霍尔三维模型
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A Framework for Exploring the Dynamics of Autonomous Work Groups in Manufacturing Organizations
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作者 Joseph W K Chan W B Lee 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期211-212,共2页
Nowadays, new paradigm of enterprise organization i s constantly changing due to the emergence of the global marketplace, the rise of information technology, and the emphasis of the social developments. This re quires... Nowadays, new paradigm of enterprise organization i s constantly changing due to the emergence of the global marketplace, the rise of information technology, and the emphasis of the social developments. This re quires a more flexible form of organization that are more adaptable to rapid cha nges in business environment such as autonomous work groups (AWGs) in order to achieve higher productivity and effectiveness. AWGs are work units responsib le for the production of goods and the provision of services. They involve team members in making decisions that are traditionally the responsibility of the sup ervisors and managers (Cohen & Bailey, 1997). Team members of AWGs are allowed t o self-regulate their behavior on jobs such as task assignments, methods for ca rrying out the work, and scheduling of activities etc. (Cohen & Ledford, 1994). For example, Motorola achieved a high organizational performance due to the succ essful implementation of AWGs in quality management (Piczak & Hauser, 1996). Xer ox also reported their operational successes based on the team-oriented work gr oups (Wageman, 1997). In recent years many organizations have replaced the traditional layers of manag ement with autonomous team-based work arrangements. Surveys indicated that the adoption of AWGs has soared in responding to the competitive business challenges . Many enterprises are making a deliberate effort to use AWGs to carry out work and operational processes as an alternative for hierarchical approaches (Lawler et al., 1995). There is a growing body of evidence that AWGs are more effective than traditionally managed groups and they contributes to organizational perform ance, such as improvement in operational performance, productivity, quality, cos t savings, employee attitude and behavior, and employee satisfaction (e.g. Pears on, 1992; Cohen & Ledford, 1994; Seers et al. 1995). Given the complexity and cognitive nature of team-based organizations, the mech anisms that the enterprises use in the development of the increasingly sophistic ated models, which can contribute to the effective functioning of AWGs, are extr emely important. The process of developing effective AWGs enables enterprises to inherent built-in intelligence of the organizations so that they will be more able to accommodate to external pressures and changes. The context of this paper is the construction of a dynamics framework and a stra tegic path for autonomous work groups in the technology-oriented manufacturing organization re-design. The framework is a conceptual one drawn from the litera ture survey. The importance of studying autonomous work groups for today’s manuf acturing organizations is claimed. Based on the General System Theory (GST), the characterization of AWGs is addressed. Three-dimensional domains such as t echnical content, service content, and relationship content are identified. A st rategic path is proposed to guide the organizations how the development of AWGs progresses at different levels of maturity that are associated with organization al effectiveness and performance. The utility of the model for AWGs is expected to provide technology-oriented organizations with a strategic path to achieve h igher organizational performance. 展开更多
关键词 autonomous work group three-dimensional dynamic s model general systems theory EFFECTIVENEss maturity level
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A Critical Discourse Analysis of Hedges in Chinese and American Spokespersons’ Remarks at Press Conference
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作者 GAO Ting 《Journal of Literature and Art Studies》 2020年第7期584-590,共7页
Hedging is a communication strategy frequently used by the spokespersons at the press conference.This thesis intends to find out the ideologies hidden behind those hedges under the guidance of Fairclough’s three-dime... Hedging is a communication strategy frequently used by the spokespersons at the press conference.This thesis intends to find out the ideologies hidden behind those hedges under the guidance of Fairclough’s three-dimensional model.As a research method of linguistics,critical discourse analysis(CDA)aims to reveal the the relationship among language,power and ideology hidden behind the language.This thesis adopts Prince’classification criteria of hedges to identify and count the different types of hedges in the research data selected from Chinese and American government websites.The analysis is conducted at the following three steps:description,interpretation and explanation.The first stage is to recognize and count the hedges in two languages,then to find their similarities and differences and the last step is to find possible reasons for those similarities and differences and the ideologies behind the hedges.Analysis results show that differences in culture values and diplomatic ideology contribute to the different ideologies. 展开更多
关键词 critical discourse analysis spokesperson’s remarks HEDGE Fairclough’s three-dimensional model IDEOLOGY
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基于霍尔三维结构的技术创新方法培训体系研究 被引量:24
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作者 岳志勇 丁惠 《科学管理研究》 CSSCI 北大核心 2013年第2期20-22,26,共4页
在分析培训和推广技术创新方法重要性的基础上,结合霍尔三维结构模型,建立了培训推广技术创新方法的三维结构模型,明确了各阶段的目标和交付物。将"四元主体"模型运用于创新方法培训主体关系研究,根据主导驱动元素的不同把四... 在分析培训和推广技术创新方法重要性的基础上,结合霍尔三维结构模型,建立了培训推广技术创新方法的三维结构模型,明确了各阶段的目标和交付物。将"四元主体"模型运用于创新方法培训主体关系研究,根据主导驱动元素的不同把四元主体模型阶段分为政府推动型、机构推动型和自觉发展型3个主要表现形态,并阐述了四元主体与三维结构模型的关系。 展开更多
关键词 霍尔三维结构 技术创新方法 培训体系 四元主体模型
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以“霍尔模式”解读跨文化交际中的传播与接受 被引量:3
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作者 颜静兰 《上海师范大学学报(哲学社会科学版)》 CSSCI 北大核心 2007年第6期91-96,共6页
通过斯图尔特.霍尔所提出的3种假设解码立场,即著名的"霍尔模式",将研究从原来的大众传媒"电视文本"研究主题推移至跨文化交际过程中广义文本的信息传递与接受,来解读跨文化交际中外来文化习俗传播与接受状况。文... 通过斯图尔特.霍尔所提出的3种假设解码立场,即著名的"霍尔模式",将研究从原来的大众传媒"电视文本"研究主题推移至跨文化交际过程中广义文本的信息传递与接受,来解读跨文化交际中外来文化习俗传播与接受状况。文章通过选取有代表性的案例进行调查,得出样本信息并加以分析,从而破解跨文化交际中的意义传递在传送者"制码"与接受者"解码"之间的非直线关系。 展开更多
关键词 霍尔模式 解码 制码 传播 跨文化交际
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Mechanism of thoracolumbar burst fractures:a biomechanical study 被引量:19
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作者 戴力扬 《Chinese Medical Journal》 SCIE CAS CSCD 2002年第3期336-338,共3页
OBJECTIVE: To investigate the mechanism associated with thoracolumbar burst fractures. METHODS: Stress distribution of the spine in the upright, flexion and extension positions was analyzed using a three-dimensional f... OBJECTIVE: To investigate the mechanism associated with thoracolumbar burst fractures. METHODS: Stress distribution of the spine in the upright, flexion and extension positions was analyzed using a three-dimensional finite element model of the spinal motion segment. RESULTS: Stress concentration was noted at the pedicle and posterosuperior part of the vertebral body near the pedicle. CONCLUSION: Stress concentration of the spine may be implicated in the biomechanical mechanism underlying thoracolumbar burst fractures. 展开更多
关键词 BIOMECHANICs Imaging three-dimensional Lumbar Vertebrae models Biological Research support Non-U.s. Gov't spinal Fractures Thoracic Vertebrae
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大气环境对岭南传统灰塑装饰的危害及相应的保护研究——以广州陈氏书院灰塑为例
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作者 石浩斌 《中国文物科学研究》 2013年第2期85-89,共5页
本文以全国重点文物保护单位广州陈氏书院内的灰塑装饰为研究对象,针对灰塑的物理化学性质和主要损坏情况,结合广州地区大气环境常年变化情况,分析了大气环境对灰塑装饰的危害,拟定了岭南地区古建筑灰塑装饰保护的全年性和季节性保护措... 本文以全国重点文物保护单位广州陈氏书院内的灰塑装饰为研究对象,针对灰塑的物理化学性质和主要损坏情况,结合广州地区大气环境常年变化情况,分析了大气环境对灰塑装饰的危害,拟定了岭南地区古建筑灰塑装饰保护的全年性和季节性保护措施,在一定程度上填补了岭南地区灰塑艺术在保养和维护方面的空白。 展开更多
关键词 岭南灰塑 陈氏书院 大气环境 病害分析 保护研究
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