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基于动态S-N曲线的飞机结构日历寿命分析

杨晓华,姚卫星,陈跃良

《中国工程科学》 2002年 第4卷 第6期   页码 33-35

摘要:

为科学地确定飞机结构的日历寿命,文章认为飞机结构的损伤历程是地面停放环境和空中疲劳载荷协同作用的结果,并提出了以动态的S-N曲线为基础,采用传统的名义应力法和Miner累积损伤理论来估算结构日历寿命的方法

关键词: 飞机结构     日历寿命     腐蚀     疲劳     S-N曲线    

用考虑置信区间长度影响的最小二乘法拟合S-N曲线

杨晓华,金平,姚卫星

《中国工程科学》 2004年 第6卷 第4期   页码 41-43

摘要:

S-N曲线是用名义应力法预测结构疲劳寿命的基础。基于试验疲劳寿命分散的物理机制,提出了一个S-N曲线试验数据处理的加权最小二乘法,此方法中每组数据的权重与该组数据的置信区间成反比。计算结果表明用考虑置信区间长度影响的最小二乘法拟合得到的S-N曲线比用一般最小二乘法得到的S-N曲线具有更高的可靠度,给出的寿命预测结果也更安全。

关键词: 置信区间     疲劳寿命     最小二乘法     S-N曲线    

基于统计分析的树脂灌注式螺栓连接疲劳强度评价

lstrok;aw Lesiuk, Carlos Alberto da Silva Rebelo, Rui Artur Bartólo Calçada, Luís

《工程(英文)》 2017年 第3卷 第6期   页码 795-805 doi: 10.1016/j.eng.2017.12.001

摘要: 但欧洲规范3(EC3)对树脂灌注式螺栓和标准螺栓的连接节点提出的疲劳强度曲线大致相同,这应得到足够的重视。此外,本研究还展示了使用黏结螺栓连接的可行性研究。最终提出疲劳设计曲线,并与欧洲和北美规范中的几个设计建议进行比较。

关键词: 疲劳     连接     结构加强     S-N曲线     树脂灌注式螺栓    

K型钢管混凝土节点疲劳性能试验研究

钟新谷,杨胜,石卫华

《中国工程科学》 2011年 第13卷 第9期   页码 97-100

摘要: 在此基础上初步提出了K型钢管混凝土节点的SN曲线,对建立K型钢管混凝土节点疲劳寿命设计准则具有一定的参考意义。

关键词: K型钢管混凝土节点     疲劳性能     SN曲线    

GTEM Cell斧形过渡块侧边曲线方程的算法

周旭

《中国工程科学》 2003年 第5卷 第9期   页码 36-38

摘要: 这样做的结果是传输损耗曲线在过渡段的分布不理想。基于修正的目的,首次给出了精确的斧形块侧边之连续曲线方程。

关键词: 吉赫兹横电磁波传输室(GTEM Cell)     斧形过渡块     侧边曲线方程     阻抗匹配    

可展曲面的焦散曲线 Research Articles

Mikl髎 HOFFMANN1,2, Imre JUH罶Z3, Ede TROLL1

《信息与电子工程前沿(英文)》 2022年 第23卷 第3期   页码 479-487 doi: 10.1631/FITEE.2000613

摘要: 考虑来自点光源或无穷远的光线经过某个镜面曲面反射时,反射光线可产生一个包络,被称为焦散曲线。本文我们研究了镜面曲面为可展曲面的情形。这些具有显式表达的焦散曲面也是可展曲面,并且与初始镜面曲面类型相同。提供了高效的算法以找到3种可展曲面(锥面、柱面和空间曲线的切线面)的焦散面。此外,提供了焦散面在当代自由形式建筑设计中的潜在应用。

关键词: 焦散曲线;可展曲面;反射光线;回归曲线    

Strength reduction factors for structural rubbercrete

Bashar S. MOHAMMED,N. J. AZMI

《结构与土木工程前沿(英文)》 2014年 第8卷 第3期   页码 270-281 doi: 10.1007/s11709-014-0265-7

摘要: Many researches have been carried out to study the fresh and hardened properties of concrete containing crumb rubber as replacement to fine aggregate by volume, yet there is no specific guideline has been developed on the mix design of the rubbercrete. The experimental program, which has been developed and reported in this paper, is designed and executed to provide such mix design guidelines. A total of 45 concrete mixes with three different water to cement ratio (0.41, 0.57 and 0.68) were cast and tested for fresh and mechanical properties of rubbercrete such as slump, air content, unit weight, compressive strength, flexural strength, splitting tensile strength and modulus of elasticity. Influence of mix design parameters such as percentage of crumb rubber replacement, cement content, water content, fine aggregate content, and coarse aggregate content were investigated. Three levels of slump value (for conventional concrete mixes) has been selected; low, medium and high slump. In each slump level, water content was kept constant. Equations for the reduction factors (RFs) for compressive strength, flexural strength, splitting tensile strength and modulus of elasticity have been developed. These RFs can be used to design rubbercrete mixes based on the conventional mix (0% crumb rubber content)

关键词: crumb rubber     recycled tire     mix design     reduction factor     strength     modulus elasticity    

Three potential benefits of the EU and IMO’s landmark efforts to monitor carbon dioxide emissions from

Shuaian WANG, Lu ZHEN, Harilaos N. PSARAFTIS

《工程管理前沿(英文)》 2021年 第8卷 第2期   页码 310-311 doi: 10.1007/s42524-020-0096-2

Morphological and mechanical characterization of a PMMA/CdS nanocomposite

Vishal MATHUR, Manasvi DIXIT, K.S. RATHORE, N. S. SAXENA, K.B. SHARMA

《化学科学与工程前沿(英文)》 2011年 第5卷 第2期   页码 258-263 doi: 10.1007/s11705-010-1014-7

摘要: Thick film of poly(methyl methacrylate) (PMMA)/CdS nanocomposite have been synthesized by the solution casting process. The nanostructure of the CdS particles has been ascertained through the small angle X-ray scattering (SAXS) technique. The surface morphological characterization of the PMMA/CdS nanocomposite has been done through scanning electron microscopy (SEM) analysis. The variation of mechanical loss factor (Tan ) with temperature and tensile properties of prepared samples have been studied using Dynamic Mechanical Analyzer (DMA). This study reveals that the glass transition temperature ( ), Young’s modulus, and fracture energy of the PMMA/CdS nanocomposite are greatly influenced by the existence of interfacial energetic interaction between dispersed CdS nanoparticles and the matrix of PMMA.

关键词: poly(methyl methacrylate) (PMMA)     filler nanoparticles     polymer semiconducting nanocomposite     tensile properties     glass transition temperature    

Decoration of vertically aligned TiO

Heba ALI, N. ISMAIL, M. S. AMIN, Mohamed MEKEWI

《能源前沿(英文)》 2018年 第12卷 第2期   页码 249-258 doi: 10.1007/s11708-018-0547-1

摘要: WO decorated photoelectrodes of titanium nanotube arrays (W-oxide TNTAs) were synthesized via a two-step process, namely, electrochemical oxidation of titanium foil and electrodeposition of W-oxide for various interval times of 1, 2, 3, 5, and 20 min to improve the photoelectrochemical performance and the amount of hydrogen generated. The synthesized photoelectrodes were characterized by various characterization techniques. The presence of tungsten in the modified TNTAs was confirmed using energy dispersive X-ray spectroscopy (EDX). Field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscope (HRTEM) proved the deposition of W-oxide as small particles staked up on the surface of the tubes at lower deposition time whereas longer times produced large and aggregate particles to mostly cover the surface of TiO nanotubes. Additionally, the incorporation of WO resulted in a shift of the absorption edge toward visible light as confirmed by UV-Vis diffuse reflectance spectroscopy and a decrease in the estimated band gap energy values hence, modified TNTAs facilitated a more efficient utilization of solar light for water splitting. From the photoelectrochemical measurement data, the optimal photoelectrode produced after 2 min of deposition time improved the photo conversion efficiency and the hydrogen generation by 30% compared to that of the pure TNTA.

关键词: titanium dioxide nanotube arrays     potentiostaticanodization     electrodeposition method     tungsten oxide     photoelectrochemical water splitting    

Cracking evolution behaviors of lightweight materials based on

Luo, S. C. Wu, Y. N. Hu, Y. N. Fu

《机械工程前沿(英文)》 2018年 第13卷 第4期   页码 461-481 doi: 10.1007/s11465-018-0481-2

摘要:

Damage accumulation and failure behaviors are crucial concerns during the design and service of a critical component, leading researchers and engineers to thoroughly identifying the crack evolution. Third-generation synchrotron radiation X-ray computed microtomography can be used to detect the inner damage evolution of a large-density material or component. This paper provides a brief review of studying the crack initiation and propagation inside lightweight materials with advanced synchrotron three-dimensional (3D) X-ray imaging, such as aluminum materials. Various damage modes under both static and dynamic loading are elucidated for pure aluminum, aluminum alloy matrix, aluminum alloy metal matrix composite, and aluminum alloy welded joint. For aluminum alloy matrix, metallurgical defects (porosity, void, inclusion, precipitate, etc.) or artificial defects (notch, scratch, pit, etc.) strongly affect the crack initiation and propagation. For aluminum alloy metal matrix composites, the fracture occurs either from the particle debonding or voids at the particle/matrix interface, and the void evolution is closely related with fatigued cycles. For the hybrid laser welded aluminum alloy, fatigue cracks usually initiate from gas pores located at the surface or sub-surface and gradually propagate to a quarter ellipse or a typical semi-ellipse profile.

关键词: fatigue crack initiation and growth     fatigue damage mechanism     damage tolerance     defect characterization     laser welded aluminum alloys    

人类蛋白质N-糖基化的十二年全基因组关联研究 Review

Anna Timoshchuk, Sodbo Sharapov, Yurii S. Aulchenko

《工程(英文)》 2023年 第26卷 第7期   页码 17-31 doi: 10.1016/j.eng.2023.03.013

摘要:

Most human-secreted and membrane-bound proteins have covalently attached oligosaccharide chains, or glycans. Glycosylation influences the physical and chemical properties of proteins, as well as their biological functions. Unsurprisingly, alterations in protein glycosylation have been implicated in a growing number of human diseases, and glycans are increasingly being considered as potential therapeutic targets, an essential part of therapeutics, and biomarkers. Although glycosylation pathways are biochemically well-studied, little is known about the networks of genes that guide the cell- and tissue-specific regulation of these biochemical reactions in humans in vivo. The lack of a detailed understanding of the mechanisms regulating glycome variation and linking the glycome to human health and disease is slowing progress in clinical applications of human glycobiology. Two of the tools that can provide much sought-after knowledge of human in vivo glycobiology are human genetics and genomics, which offer a powerful data-driven agnostic approach for dissecting the biology of complex traits. This review summarizes the current state of human populational glycogenomics. In Section 1, we provide a brief overview of the N-glycan's structural organization, and in Section 2, we give a description of the major blood plasma glycoproteins. Next, in Section 3, we summarize, systemize, and generalize the results from current N-glycosylation genome-wide association studies (GWASs) that provide novel knowledge of the genetic regulation of the populational variation of glycosylation. Until now, such studies have been limited to an analysis of the human blood plasma N-glycome and the N-glycosylation of immunoglobulin G and transferrin. While these three glycomes make up a rather limited set compared with the enormous multitude of glycomes of different tissues and glycoproteins, the study of these three does allow for powerful analysis and generalization. Finally, in Section 4, we turn to genes in the established loci, paying particular attention to genes with strong support in Section 5. At the end of the review, in Sections 6 and 7, we describe special cases of interest in light of new discoveries, focusing on possible mechanisms of action and biological targets of genetic variation that have been implicated in human protein N-glycosylation.

关键词: 糖组学     聚糖     N-糖基化     基因组学     遗传学     全基因组关联研究    

Intelligent algorithm for optimal meter placement and bus voltage estimation in ring main distribution system

RAMESH, N. CHAKRABORTY, S. P. CHOWDHURY

《能源前沿(英文)》 2012年 第6卷 第1期   页码 47-56 doi: 10.1007/s11708-011-0159-5

摘要: The advancement in power distribution system poses a great challenge to power engineering researchers on how to best monitor and estimate the state of the distribution network. This paper is executed in two stage processes. The first stage is to identify the optimal location for installation of monitoring instrument with minimal investment cost. The second stage is to estimate the bus voltage magnitude, where real time measurement is conducted and measured through identified meter location which is more essential for decision making in distribution supervisory control and data acquisition system (DSCADA). The hybrid intelligent technique is applied to execute the above two algorithms. The algorithms are tested with institute of electrical and electronics engineers (IEEE) and Tamil Nadu electricity board (TNEB) benchmark systems. The simulated results proves that the swarm tuned artificial neural network (ANN) estimator is best suited for accurate estimation of voltage with different noise levels.

关键词: artificial intelligence     power distribution control     state estimation    

Mechanical properties of steel, glass, and hybrid fiber reinforced reactive powder concrete

Neaz SHEIKH, Muhammad N.S. HADI

《结构与土木工程前沿(英文)》 2019年 第13卷 第4期   页码 998-1006 doi: 10.1007/s11709-019-0533-7

摘要: This study examines the properties of fiber-reinforced reactive powder concrete (FR-RPC). Steel fibers, glass fibers, and steel-glass hybrid fibers were used to prepare the FR-RPC. The non-fibrous reactive powder concrete (NF-RPC) was prepared as a reference mix. The proportion of fibers by volume for all FR-RPC mixes was 1.5%. Steel fibers of 13 mm length and 0.2 mm diameter were used to prepare the steel fiber-reinforced RPC (SFR-RPC). Glass fibers of 13 mm length and 1.3 mm diameter were used to prepare the glass fiber-reinforced RPC (GFR-RPC). The hybrid fiber-reinforced RPC (HFR-RPC) was prepared by mixing 0.9% steel fibers and 0.6% glass fibers. Compressive strength, axial load-axial deformation behavior, modulus of elasticity, indirect tensile strength, and shear strength of the RPC mixes were investigated. The results showed that SFR-RPC achieved higher compressive strength, indirect tensile strength and shear strength than NF-RPC, GFR-RPC, and HFR-RPC. Although the compressive strengths of GFR-RPC and HFR-RPC were slightly lower than the compressive strength of NF-RPC, the shear strengths of GFR-RPC and HFR-RPC were higher than that of NF-RPC.

关键词: reactive powder concrete     steel fiber     glass fiber     hybrid fiber    

End-use energy utilization efficiency of Nigerian residential sector

ABAM,Olayinka S. OHUNAKIN,Bethrand N. NWANKWOJIKE,Ekwe B. EKWE

《能源前沿(英文)》 2014年 第8卷 第3期   页码 322-334 doi: 10.1007/s11708-014-0329-3

摘要: In this paper, the end-use efficiencies of the different energy carriers and the overall energy efficiency in the Nigerian residential sector (NRS) were estimated using energy and exergy analysis. The energy and exergy flows were considered from 2006 to 2011. The overall energy efficiency ranges from 19.15% in 2006 to 20.19% in 2011 with a mean of (19.96±0.23)% while the overall exergy efficiency ranges from 4.34% in 2006 to 4.40% in 2011 with a mean of (4.31±0.059)%. The energy and exergy efficiency margin was 15.58% with a marginal improvement of 0.07% and 0.02%, respectively when compared with previous results. The contribution of the energy carriers to the total energy and exergy inputs were 1.45% and 1.43% for electricity, 1.95% and 3% for fossil fuel and 96.6% and 95.57% for bio-fuel. The result shows that approximately 65% of the residence use wood and biomass for domestic cooking and heating, and only a fraction of the residence have access to electricity. LPG was found to be the most efficient while kerosene, charcoal, wood and other biomass the least in this order. Electricity utilization exergy efficiency is affected by vapor-compression air conditioning application apart from low potential energy applications. In addition, this paper has suggested alternatives in the end-use application and has demonstrated the relevance of exergy analysis in enhancing sustainable energy policies and management and improved integration techniques.

关键词: end-use     energy     exergy efficiency     residential sector     Nigeria    

标题 作者 时间 类型 操作

基于动态S-N曲线的飞机结构日历寿命分析

杨晓华,姚卫星,陈跃良

期刊论文

用考虑置信区间长度影响的最小二乘法拟合S-N曲线

杨晓华,金平,姚卫星

期刊论文

基于统计分析的树脂灌注式螺栓连接疲劳强度评价

lstrok;aw Lesiuk, Carlos Alberto da Silva Rebelo, Rui Artur Bartólo Calçada, Luís

期刊论文

K型钢管混凝土节点疲劳性能试验研究

钟新谷,杨胜,石卫华

期刊论文

GTEM Cell斧形过渡块侧边曲线方程的算法

周旭

期刊论文

可展曲面的焦散曲线

Mikl髎 HOFFMANN1,2, Imre JUH罶Z3, Ede TROLL1

期刊论文

Strength reduction factors for structural rubbercrete

Bashar S. MOHAMMED,N. J. AZMI

期刊论文

Three potential benefits of the EU and IMO’s landmark efforts to monitor carbon dioxide emissions from

Shuaian WANG, Lu ZHEN, Harilaos N. PSARAFTIS

期刊论文

Morphological and mechanical characterization of a PMMA/CdS nanocomposite

Vishal MATHUR, Manasvi DIXIT, K.S. RATHORE, N. S. SAXENA, K.B. SHARMA

期刊论文

Decoration of vertically aligned TiO

Heba ALI, N. ISMAIL, M. S. AMIN, Mohamed MEKEWI

期刊论文

Cracking evolution behaviors of lightweight materials based on

Luo, S. C. Wu, Y. N. Hu, Y. N. Fu

期刊论文

人类蛋白质N-糖基化的十二年全基因组关联研究

Anna Timoshchuk, Sodbo Sharapov, Yurii S. Aulchenko

期刊论文

Intelligent algorithm for optimal meter placement and bus voltage estimation in ring main distribution system

RAMESH, N. CHAKRABORTY, S. P. CHOWDHURY

期刊论文

Mechanical properties of steel, glass, and hybrid fiber reinforced reactive powder concrete

Neaz SHEIKH, Muhammad N.S. HADI

期刊论文

End-use energy utilization efficiency of Nigerian residential sector

ABAM,Olayinka S. OHUNAKIN,Bethrand N. NWANKWOJIKE,Ekwe B. EKWE

期刊论文