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Boundary conditions for axisymmetric piezoelectric cylinder

Baosheng ZHAO, Di WU, Xi CHEN

《机械工程前沿(英文)》 2013年 第8卷 第4期   页码 401-408 doi: 10.1007/s11465-013-0272-8

摘要:

For axisymmetric piezoelectric cylinder, the reciprocal theorem and the axisymmetric general solution of piezoelasticity are applied in a novel way to obtain the appropriate stress and mixed boundary conditions accurate to all orders for the cylinder of general edge geometry and loadings. A decay analysis technique developed by Gregory and Wan is converted into necessary conditions on the end-data of axisymmetric piezoelectric circular cylinder, and the rapidly decaying solution is established. The prescribed end-data of the circle cylinder must satisfy these conditions in order that they could generate a decaying state within the cylinder. When stress and mixed conditions are imposed on the end of cylinder, these decaying state conditions for the case of axisymmetric deformation of piezoelectric cylinder are derived explicitly. They are then used for the correct formulation of boundary conditions for the theory solution (or the interior solution) of axisymmetric piezoelectric cylinder. The results of the present paper enable us to establish a set of correct boundary conditions, most of which are obtained for the first time.

关键词: solid and structures     the axisymmetric deformation     the piezoelectric circular cylinder     the refined theory     Bessel’s Function    

Refined analysis of axi-symmetric circular cylinder in the axial magnetic field without ad hoc assumption

Baosheng ZHAO, Yang GAO, Yingtao ZHAO, Dechen ZHANG

《机械工程前沿(英文)》 2011年 第6卷 第3期   页码 318-323 doi: 10.1007/s11465-011-0232-0

摘要:

The refined theory for axi-symmetric magnetoelastic circular cylinder is deduced systematically and directly from linear magnetoelasticity theory. Based on the general solution of magnetoelastic equation and the Lur’e method, the refined theory yields the solutions for magnetoelastic circular cylinder without ad hoc assumptions. On the basis of the refined theory developed in the present study, solutions are obtained for magnetoelastic circular cylinder with homogeneous and non-homogenous boundary conditions, respectively. For the circular cylinder with homogeneous boundary conditions, the refined theory provides exact solutions that satisfy all of the governing equations. The exact solutions can be divided into three parts: the 2-orders equation, the transcendental equation, and the magnetic equation. In the case of non-homogenous boundary conditions, the approximate governing equations are accurate up to the high-order terms with respect to cylinder radius.

关键词: refined analysis     axially symmetric deformation     circular cylinder     Bessel’s function     axial magnetic field    

3S技术在区域生态功能区划中的应用——以河南省濮阳市为案例

卞有生,蔡博峰,赵楠

《中国工程科学》 2005年 第7卷 第12期   页码 54-60

摘要:

生态功能区划是区域社会经济协调发展的基础性工作,3S技术则是保证区划科学与准确的重要技术手段。以河南省濮阳市为例,介绍了3S技术在区域生态功能区划中的应用及其优势与特点,即数据的准确性、现势性和科学性得到进一步提高,而且空间分析功能充分实现了不同权重生态因子的叠加,同时在区划过程中充分考虑生态格局对生态功能的影响

关键词: 生态功能区划     3S     空间分析     生态格局    

A discussion of objective function representation methods in global optimization

Panos M. PARDALOS, Mahdi FATHI

《工程管理前沿(英文)》 2018年 第5卷 第4期   页码 515-523 doi: 10.15302/J-FEM-2018044

摘要:

Non-convex optimization can be found in several smart manufacturing systems. This paper presents a short review on global optimization (GO) methods. We examine decomposition techniques and classify GO problems on the basis of objective function representation and decomposition techniques. We then explain Kolmogorov’s superposition and its application in GO. Finally, we conclude the paper by exploring the importance of objective function representation in integrated artificial intelligence, optimization, and decision support systems in smart manufacturing and Industry 4.0.

关键词: global optimization     decomposition techniques     multi-objective     DC programming     Kolmogorov’s superposition     space-filling curve     smart manufacturing and Industry 4.0    

虚拟企业CRM系统的原型分析和设计

邓峰,刘现民,杨肖鸳

《中国工程科学》 2004年 第6卷 第10期   页码 83-85

摘要:

描述了虚拟企业CRM(客户关系管理)系统的特点,分析了虚拟企业CRM的信息流,在此基础上给出了一个分布式的虚拟企业CRM运作系统,其必须由虚拟企业CRM的协调企业统一管理和协调,并构造了虚拟企业CRM系统中的协调企业的功能模块参考结构,提出了实现虚拟企业CRM的技术体系参考模型。

关键词: 虚拟企业的CRM     信息流     功能模块     技术体系    

Lung function and air pollution exposure in adults with asthma in Beijing: a 2-year longitudinal panel

《医学前沿(英文)》 2022年 第16卷 第4期   页码 574-583 doi: 10.1007/s11684-021-0882-1

摘要: The effect of air pollution on the lung function of adults with asthma remains unclear to date. This study followed 112 patients with asthma at 3-month intervals for 2 years. The pollutant exposure of the participants was estimated using the inverse distance weight method. The participants were divided into three groups according to their lung function level at every visit. A linear mixed-effect model was applied to predict the change in lung function with each unit change in pollution concentration. Exposure to carbon monoxide (CO) and particles less than 2.5 micrometers in diameter (PM2.5) was negatively associated with large airway function in participants. In the severe group, exposure to chronic sulfur dioxide (SO2) was negatively associated with post-bronchodilator forced expiratory flow at 50%, between 25% and 75% of vital capacity % predicted (change of 95% CI per unit: −0.34 (−0.55, −0.12), −0.24 (−0.44, −0.03), respectively). In the mild group, the effect of SO2 on the small airways was similar to that in the severe group, and it was negatively associated with large airway function. Exposure to CO and PM2.5 was negatively associated with the large airway function of adults with asthma. The negative effects of SO2 were more evident and widely observed in adults with severe and mild asthma than in adults with moderate asthma. Patients with asthma react differently to air pollutants as evidenced by their lung function levels.

关键词: lung function     asthma     air pollution     adult    

The function and regulation of OTU deubiquitinases

Jiansen Du, Lin Fu, Yingli Sui, Lingqiang Zhang

《医学前沿(英文)》 2020年 第14卷 第5期   页码 542-563 doi: 10.1007/s11684-019-0734-4

摘要: Post-translational modification of cellular proteins by ubiquitin regulates numerous cellular processes, including cell division, immune responses, and apoptosis. Ubiquitin-mediated control over these processes can be reversed by deubiquitinases (DUBs), which remove ubiquitin from target proteins and depolymerize polyubiquitin chains. Recently, much progress has been made in the DUBs. In humans, the ovarian tumor protease (OTU) subfamily of DUBs includes 16 members, most of which mediate cell signaling cascades. These OTUs show great variation in structure and function, which display a series of mechanistic features. In this review, we provide a comprehensive analysis of current progress in character, structure and function of OTUs, such as the substrate specificity and catalytic activity regulation. Then we discuss the relationship between some diseases and OTUs. Finally, we summarize the structure of viral OTUs and their function in immune escape and viral survival. Despite the challenges, OTUs might provide new therapeutic targets, due to their involvement in key regulatory processes.

关键词: ubiquitin     OTU deubiquitinases     structure     function     regulation    

类差分平衡函数的性质及其应用

张文英,李世取

《中国工程科学》 2004年 第6卷 第3期   页码 45-52

摘要:

定义了布尔函数的类差分和类差分平衡函数,研究了类差分平衡函数的密码学性质以及构造方法。作为类差分平衡函数的应用,给出了〓上逻辑函数是完全非线性函数的充要条件,并在首先分析得到所有四元类差分平衡函数的基础上,编程搜索出〓上所有的完全非线性函数。

关键词: Bent函数     完全非线性函数     2-基展开     类差分     类自相关函数     类差分平衡函数    

Application of python-based Abaqus preprocess and postprocess technique in analysis of gearbox vibration and noise reduction

Guilian YI, Yunkang SUI, Jiazheng DU

《机械工程前沿(英文)》 2011年 第6卷 第2期   页码 229-234 doi: 10.1007/s11465-011-0128-z

摘要:

To reduce vibration and noise, a damping layer and constraint layer are usually pasted on the inner surface of a gearbox thin shell, and their thicknesses are the main parameters in the vibration and noise reduction design. The normal acceleration of the point on the gearbox surface is the main index that can reflect the vibration and noise of that point, and the normal accelerations of different points can reflect the degree of the vibration and noise of the whole structure. The K-S function is adopted to process many points’ normal accelerations as the comprehensive index of the vibration characteristics of the whole structure, and the vibration acceleration level is adopted to measure the degree of the vibration and noise. Secondary development of the Abaqus preprocess and postprocess on the basis of the Python scripting programming automatically modifies the model parameters, submits the job, and restarts the analysis totally, which avoids the tedious work of returning to the Abaqus/CAE for modifying and resubmitting and improves the speed of the preprocess and postprocess and the computational efficiency.

关键词: Abaqus secondary development     Python language     vibration and noise reduction     K-S function     vibration acceleration level    

Analytical solutions of three-dimensional contaminant transport in uniform flow field in porous media: A library

Hongtao WANG, Huayong WU

《环境科学与工程前沿(英文)》 2009年 第3卷 第1期   页码 112-128 doi: 10.1007/s11783-008-0067-z

摘要: The purpose of this study is to present a library of analytical solutions for the three-dimensional contaminant transport in uniform flow field in porous media with the first-order decay, linear sorption, and zero-order production. The library is constructed using Green's function method (GFM) in combination with available solutions. The library covers a wide range of solutions for various conditions. The aquifer can be vertically finite, semi-infinitive or infinitive, and laterally semi-infinitive or infinitive. The geometry of the sources can be of point, line, plane or volumetric body; and the source release can be continuous, instantaneous, or by following a given function over time. Dimensionless forms of the solutions are also proposed. A computer code FlowCAS is developed to calculate the solutions. Calculated results demonstrate the correctness of the presented solutions. The library is widely applicable to solve contaminant transport problems of one- or multiple- dimensions in uniform flow fields.

关键词: solution library     contaminant transport     analytical solution     dispersion and advection     porous media     type curve     Green's function method (GFM)    

Quality Function Deployment Implementation in Construction: A Systematic Literature Review

Elizabeth A. Cudney,William L. Gillis

《工程管理前沿(英文)》 2016年 第3卷 第3期   页码 224-230 doi: 10.15302/J-FEM-2016036

摘要: The construction of new buildings represents a significant investment. The goal of new building construction is to maximize value and minimize cost while staying on time and within budget. Translating customer requirements into engineering terms for new construction design is vital for a construction project to be successful. Quality function deployment has been successfully used in product development to capture the voice of the customer and translate it into engineering characteristics. Quality function deployment then carries these parameters into production and service to ensure the voice of the customer is being met with the final product. The house of quality, a tool within quality function deployment, can provide a means for comparison of owner’s project requirements and the proposed design, along with identifying how the design decisions impact meeting customer requirements and green building requirements. Quality function deployment can effectively link the project phases through design and construction and into operations and maintenance to ensure the owner’s project requirements are met with the final building. This research identifies and categorizes studies of quality function deployment applications in construction. The research method used is a systematic literature review from databases related to quality function deployment in the construction industry published in the periodicals through 2016. The principal findings of implementations, practices, and integrated approaches are then summarized. This article intends to propel further research of quality function deployment in the construction sector.

关键词: construction     engineering management     quality function deployment     systematic review    

Design and evaluation of a novel biopsy needle with hemostatic function

《机械工程前沿(英文)》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0738-7

摘要: Biopsy is a method commonly used for early cancer diagnosis. However, bleeding complications of widely available biopsy are risky for patients. Safer biopsy will result in a more accurate cancer diagnosis and a decrease in the risk of complications. In this article, we propose a novel biopsy needle that can reduce bleeding during biopsy procedures and achieve stable hemostasis. The proposed biopsy needle features a compact structure and can be operated easily by left and right hands. A predictive model for puncture force and tip deflection based on coupled Eulerian–Lagrangian (CEL) method is developed. Experimental results show that the biopsy needle can smoothly deliver the gelatin sponge hemostatic plug into the tissue. Although the hemostatic plug bends, the overall delivery process is stable, and the hemostatic plug retains in the tissue without being affected by the withdrawal of the needle. Further experiments indicate that the specimens are well obtained and evenly distributed in the groove of the outer needle without scattering. Our proposed design of biopsy needle possesses strong ability of hemostasis, tissue cutting, and tissue retention. The CEL model accurately predicts the peak of puncture force and produces close estimation of the insertion force at the postpuncture stage and tip position.

关键词: cancer diagnosis     biopsy needle     hemostatic function     predictive model     coupled Eulerian−Lagrangian    

Regulation and function of histone acetyltransferase MOF

null

《医学前沿(英文)》 2014年 第8卷 第1期   页码 79-83 doi: 10.1007/s11684-014-0314-6

摘要:

The mammalian MOF (male absent on the first), a member of the MYST (MOZ, YBF2, SAS2, and Tip60) family of histone acetyltransferases (HATs), is the major enzyme that catalyzes the acetylation of histone H4 on lysine 16. Acetylation of K16 is a prevalent mark associated with chromatin decondensation. MOF has recently been shown to play an essential role in maintaining normal cell functions. In this study, we discuss the important roles of MOF in DNA damage repair, apoptosis, and tumorigenesis. We also analyze the role of MOF as a key regulator of the core transcriptional network of embryonic stem cells.

关键词: MOF     histone acetyltransferase     DNA damage repair     tumorigenesis     embryonic stem cells    

Transfer function solving, simulating and testing of thermal dynamics characteristics of a ballscrew

Junyong XIA, Bo WU, Youmin HU, Tielin SHI,

《机械工程前沿(英文)》 2010年 第5卷 第2期   页码 233-241 doi: 10.1007/s11465-010-0014-0

摘要: Based on the theory of heat transfer, the transfer function between the thermal deformation of any point on the lead screw and the temperature of heat sources of a ballscrew under the influence of multi-changeable heat sources is solved by using the Laplace transform method. By solving the amplitude-frequency characteristics and phase-frequency characteristics of the transfer function, the steady-state response of thermal deformation of the ballscrew is obtained, and the thermal dynamics characteristics of the lead screw under the influence of multi-heat sources are further studied. Comparing with the result of finite-element simulation, the theoretical analyzing result accords with the steady-state part of the finite-element simulating result. Through tests of the steady-state response of thermal deformation, the thermal dynamics characteristics are further studied. The curves of tests by and large accord with the theoretical analyzing result, which shows that the method of transfer function is correct and valid in solving the steady-state response of thermal deformation.

关键词: ballscrew     Laplace transform     transfer function     thermal dynamic characteristics    

Comparison in executive function in Chinese preterm and full-term infants at eight months

null

《医学前沿(英文)》 2018年 第12卷 第2期   页码 164-173 doi: 10.1007/s11684-017-0540-9

摘要:

Executive function (EF) is increasingly recognized as being responsible for adverse developmental outcomes in preterm-born infants. Several perinatal factors may lead to poor EF development in infancy, and the deficits in EF can be identified in infants as young as eight months. A prospective cohort study was designed to study the EF in Chinese preterm infants and examine the relationship between EF in preterm infants and maternal factors during perinatal period. A total of 88 preterm infants and 88 full-term infants were followed from birth to eight months (corrected age). Cup Task and Planning Test was applied to assess the EF of infants, and the Bayley Scale of Infant Development (BSID-III) was used to evaluate cognitive (MDI) and motor abilities (PDI) of infants. In comparison with full-term infants, the preterm infants performed more poorly on all measures of EF including working memory, inhibition to prepotent responses, inhibition to distraction, and planning, and the differences remained after controlling the MDI and PDI. Anemia and selenium deficiency in mothers during pregnancy contributed to the differences in EF performance. However, maternal depression, hypertension, and diabetes during pregnancy were not related to the EF deficits in preterm infants. Future research should focus on the prevention of anemia and selenium deficiency during pregnancy and whether supplementing selenium in mothers during pregnancy can prevent further deterioration and the development of adverse outcomes of their offspring.

关键词: executive function (EF)     preterm infant     working memory     inhibition to prepotent response     inhibition to distraction     planning    

标题 作者 时间 类型 操作

Boundary conditions for axisymmetric piezoelectric cylinder

Baosheng ZHAO, Di WU, Xi CHEN

期刊论文

Refined analysis of axi-symmetric circular cylinder in the axial magnetic field without ad hoc assumption

Baosheng ZHAO, Yang GAO, Yingtao ZHAO, Dechen ZHANG

期刊论文

3S技术在区域生态功能区划中的应用——以河南省濮阳市为案例

卞有生,蔡博峰,赵楠

期刊论文

A discussion of objective function representation methods in global optimization

Panos M. PARDALOS, Mahdi FATHI

期刊论文

虚拟企业CRM系统的原型分析和设计

邓峰,刘现民,杨肖鸳

期刊论文

Lung function and air pollution exposure in adults with asthma in Beijing: a 2-year longitudinal panel

期刊论文

The function and regulation of OTU deubiquitinases

Jiansen Du, Lin Fu, Yingli Sui, Lingqiang Zhang

期刊论文

类差分平衡函数的性质及其应用

张文英,李世取

期刊论文

Application of python-based Abaqus preprocess and postprocess technique in analysis of gearbox vibration and noise reduction

Guilian YI, Yunkang SUI, Jiazheng DU

期刊论文

Analytical solutions of three-dimensional contaminant transport in uniform flow field in porous media: A library

Hongtao WANG, Huayong WU

期刊论文

Quality Function Deployment Implementation in Construction: A Systematic Literature Review

Elizabeth A. Cudney,William L. Gillis

期刊论文

Design and evaluation of a novel biopsy needle with hemostatic function

期刊论文

Regulation and function of histone acetyltransferase MOF

null

期刊论文

Transfer function solving, simulating and testing of thermal dynamics characteristics of a ballscrew

Junyong XIA, Bo WU, Youmin HU, Tielin SHI,

期刊论文

Comparison in executive function in Chinese preterm and full-term infants at eight months

null

期刊论文