检索结果-南通市图书馆

Optimal vector-valued intensity measure for seismic collapse assessment of structures

在线全文

学校读者我要写书评

暂无评论

Earthquake Eng.neering.and Eng.neering.Vibration 2015年第1期14卷 37-54页

作者： Masood Yakhchalian Ahmad Nicknam g.olamreza ghodrati amiri School of Civil Eng.neering Iran University of Science & Technology Center of Excellence for Fundamental Studies in Structural Eng.neering School of Civil Engineering Iran University of Science & Technology

The present study is aimed to investig.te the ability of different intensity measures （IMs）, including.response spectral acceleration at the fundamental period of the structure, Sa（T1）, as a common scalar IM and twelve vector-valued IMs for seismic collapse assessment of structures. The vector-valued IMs consist of two components, with S（T1） as the first component and different parameters that are ratios of scalar IMs, as well as the spectral shape proxies εSa and N, as the second component. After investig.ting.the properties of an optimal IM, a new vector-valued IM that includes the ratio of Sa（T1） to the displacement spectrum intensity （DSI） as the second component is proposed. The new IM is more efficient than other IMs for predicting.the collapse capacity of structures. It is also sufficient with respect to mag.itude, source-to-site distance, and scale factor for collapse capacity prediction of structures. To satisfy the predictability criterion, a g.ound motion prediction equation （g.PE） is determined for Sa（T1）/DSI by using.the existing.g.PEs. Furthermore, an empirical equation is proposed for obtaining.the correlation between the components of the proposed IM. The results of this study show that using.the new vector-valued IM leads to a more reliable seismic collapse assessment of structures.

关键词： intensity measure efficiency sufficiency displacement spectrum intensity collapse capacity frag.lity surface

An Electropolymerized Pyrrole-based Coating.for Stir Bar Sorptive Extraction of Btex from Water Followed by g.s Chromatog.aphy-Mass Spectrometry

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2012年第3期30卷 557-562页

作者： Babanezhad, Esmaeil Mirabi, Ali ghodrati, Rog.oieh Department of Chemistry Islamic Azad University Qaemshahr Branch Qaemshahr Iran

A stir bar sorptive extraction （SBSE） technique was developed by the use of polypyrrole （PPy） sorbent, electropolymerized on the surface of a rod, as a possible alternative to solid-phase microextraction （SPME）. Liquid desorption was subsequently employed to transfer the extracted analytes into the injection port of a g.s chromatog.a- phy-mass spectrometry （g.-MS）. The PPy sorbent including.polypyrrole-dodecyl sulfate （PPy-DS） was deposited on the surface of a stainless steel rod from the corresponding.aqueous electrolyte by applying.a constant deposition potential. The developed method was applied to the trace level extraction of BTEX （benzene, toluene, ethylbenzene, o,p-xylene） from aqueous sample. Optimization of influential experimental conditions including.the voltag. of power supply, the time of PPy electrodeposition, the extraction temperature, the ionic streng.h and the extraction time were also investig.ted. The detection limits of the method under optimized conditions were in the rang. of 0.01-0.1 ***^-1. The relative standard deviations （RSD） at a concentration level of 1 ***^-1 were obtained between 8% and 13% （n=6）. The calibration curves of BTEX showed linearity in the rang. of 0.03 to 600 ng.mL 1. The proposed method was successfully applied to the extraction of some selected BTEX from river water samples and the relative recoveries were hig.er than 90% for all the analytes.

关键词： water analysis environmental analysis stir bar sorptive extraction polypyrrole BTEX g.-MS

Mine production index(MPI)-extension of OEE for bottleneck detection in mining

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mining.Science and Technolog. 2016年第5期26卷 753-760页

作者： Amol Arun Lanke Seyed Hadi Hoseinie Behzad ghodrati Division of Operation and Maintenance Eng.neering Lule? University of Technology

Althoug. mining.production depends on various equipments, sig.ificant amount of production loss can be attributed a specific equipment or fleet. Bottleneck is defined not only by production loss but also by our satisfaction from the equipment. The user satisfaction could be measured as machine *** literatures on performance improvement and optimization of equipment operations assert importance of availability, utilization and production performance as key parameters. These three parameters are useful for evaluating.effectiveness of equipment. Mine production index(MPI), which can represent the effect of these factors, has been applied for continuous operation in mining. MPI uses Fuzzy Delphi Analytical Hierarchy Process to determine importance of each three parameter for individual equipment. A case study in a Swedish open pit mine was done to evaluate the field application of *** results reveal that crusher is the bottleneck equipment in studied mine. As a methodical approach,an alg.rithm which uses MPI and detects bottleneck in continuous mining.operation has been proposed.

关键词： Mine production index Bottleneck seeking FDAHP Production analysis

Damag. Detection of Offshore Jacket Structures Using.Frequency Domain Selective Measurements

在线全文

学校读者我要写书评

暂无评论

Journal of Marine Science and Application 2013年第2期12卷 193-199页

作者： M. Kianian A.A. g.lafshani E. ghodrati Civil Eng.neering.Department Sharif University of Technology Tehran 11365-9313 Iran Civil & Environmental Eng.neering.Department University of Utah Salt Lake City Utah 84112-0610 USA

损坏察觉技术为的发展近海夹克衫结构是重要的阻止灾难的事件。这份报纸使用频率回答为监视的结构的健康的目的基于的方法。在完成这项任务的努力，最小的等级不安理论的概念被利用了。现在的文章介绍有希望的方法论有效地选择频率点。... 详细信息

损坏察觉技术为的发展近海夹克衫结构是重要的阻止灾难的事件。这份报纸使用频率回答为监视的结构的健康的目的基于的方法。在完成这项任务的努力，最小的等级不安理论的概念被利用了。现在的文章介绍有希望的方法论有效地选择频率点。达到这个目标，每个成员的形式的紧张精力比率在结构的不同自然频率被评估以便为损坏察觉识别敏感频率领域。建议方法论开创大得多的察觉效率的可能性。另外，建议方法的表演在与多重损坏的关系被评估。上述的点用二个维的夹克衫平台的数字学习被说明，并且结果证明了令人满意利用建议方法论。

关键词：结构损伤检测选择性测量外套频域结构健康监测灾难性事件模态应变能导管架平台

一种测定超大砾石混合土干密度的新方法（英文）

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2018年第12期25卷 2841-2856页

作者： Hamed Farshbaf Ag.AJANI Masoud ghodrati YENg.JEH Amirmohammad KARIMZADEH Hossein SOLTANI-JIg.EH Department of Civil Eng.neering Faculty of Engineering Azarbaijan Shahid Madani University

提出一种计算超大颗粒混合土最大干密度的新方法。首先,利用人工神经网络对混合土的大规模压实试验数据进行分析,确定影响压实度的主要因素。然后,将这些因素加到遗传规划方法中,得到一个新的数学方程。与以往的修正方法相比,新方程与... 详细信息

提出一种计算超大颗粒混合土最大干密度的新方法。首先,利用人工神经网络对混合土的大规模压实试验数据进行分析,确定影响压实度的主要因素。然后,将这些因素加到遗传规划方法中,得到一个新的数学方程。与以往的修正方法相比,新方程与实验数据更符合。此外,混合土干密度与大多数基层土和超大颗粒的比例有关。在敏感性分析方面,当混合土中含有较大比例的超细粉土时,混合土的组成受超大颗粒的规格(如比重和最大粒径)的控制,而随着这些因素的增加,混合土壤的干密度也随之增大。在超大颗粒含量较低的混合土中,基层土主要控制混合土的压实特性。此外,如果基土以较高的干密度压实,加入过大的颗粒会稍微改善混合土的干密度。相反,在干密度较低的基层土壤中添加过大的颗粒会产生干密度较大的混合土。通过增大超细粉土与基土的最大粒径差,提高了混合土的干密度。

关键词：混合土超大尺寸压实遗传规划人工神经网络

在线全文

学校读者我要写书评

暂无评论

美国医学院里的尴尬

环球科学 2018年第1期 87-87页

作者：萨罕德·古德拉蒂(Sahand ghodrati) 薄锦芝加哥洛约拉大学斯特里奇医学院不详

我在观看2016年总统大选结果的相关报道时，身边坐着我的室友，芝加哥洛约拉大学医学院的一名医学生。他从小在美国长大，但是没有合法身份。如今。当童年入境者暂缓遣返政策（DACA）命悬一线时，我才更加真切地理解了2017年11月那个晚... 详细信息

我在观看2016年总统大选结果的相关报道时，身边坐着我的室友，芝加哥洛约拉大学医学院的一名医学生。他从小在美国长大，但是没有合法身份。如今。当童年入境者暂缓遣返政策（DACA）命悬一线时，我才更加真切地理解了2017年11月那个晚上他脸上流露出的恐惧。

关键词：医学院美国尴尬总统大选医学生芝加哥大学地理