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“共享单车”元数据框架体系设计研究 被引量:1
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作者 狄亚飞 张敏 《图书情报导刊》 2017年第7期59-63,共5页
"互联网+"环境下共享商品正迅速崛起,并从多角度、全方位深刻地改变着人们的生活。"共享单车"作为共享商品的典型代表,其使用与管理中产生的数据具有重要价值,对这些数据的组织、检索、共享需要进行元数据规范。选... "互联网+"环境下共享商品正迅速崛起,并从多角度、全方位深刻地改变着人们的生活。"共享单车"作为共享商品的典型代表,其使用与管理中产生的数据具有重要价值,对这些数据的组织、检索、共享需要进行元数据规范。选取国内外8种典型的"共享单车"为研究对象,分析了"共享单车"的概念、类型、特点和发展模式,依据多元测定原则从4个方面获取"共享单车"涉及的各种数据,最终构建了其元数据框架体系。 展开更多
关键词 共享单车 共享商品 元数据 框架体系 多元测定
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Determination of Transport Properties for Dilute Gas Mixtures Involving Carbon Tetrafluoride
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作者 Mohammad Mehdi Papari Jalil Moghadasi +1 位作者 Soodabeh Nikmanesh Mahmood RezaDehghan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第2期297-305,共9页
In our previous work,we calculated transport properties of pure gaseous polyatomic carbon tetrafluoride(CF4) and five equimolar binary gas mixtures of CF4 with noble gases through inversion technique.The present work ... In our previous work,we calculated transport properties of pure gaseous polyatomic carbon tetrafluoride(CF4) and five equimolar binary gas mixtures of CF4 with noble gases through inversion technique.The present work is a continuation of our studies on determining the transport properties of binary gas mixtures CF4 with some gases including three diatomic molecules CO,N2,and O2,a linear polyatomic CO2,and two non-linear polyatomic molecules SF6 and CH4.The Chapman-Enskog and Vesovic-Wakeham methods as well as inversion procedure are used to determine the viscosities,diffusivities,and thermal conductivities,which deviates from the literature values within 1%,4%,and 5%,respectively. 展开更多
关键词 principle of corresponding states inversion method kinetic theory of gases DIFFUSIVITY thermal conductivity VISCOSITY transport properties
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Rapid determination of eight aristolochic acid analogues in five Aristolochiaceae plants by ultra-high performance liquid chromatography quadrupole/time-of-flight mass spectrometry 被引量:14
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作者 孔德强 高慧媛 +2 位作者 李辛 路金才 袁丹 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2015年第6期364-375,共12页
Aristolochic acids (AAs) and aristololactams (ALs) are commonly found in some Aristolochiaceae plants, and they have been reported to be AA nephropathy (AAN), nephrotoxicity and carcinogenicity. In the present s... Aristolochic acids (AAs) and aristololactams (ALs) are commonly found in some Aristolochiaceae plants, and they have been reported to be AA nephropathy (AAN), nephrotoxicity and carcinogenicity. In the present study, we established an ultra high performance liquid chromatography (UHPLC) coupled with quadmpole/time-of-flight mass spectrometry (Q/TOF-MS) method for the rapid analysis of eight AA analogues in 19 samples originated from the five Aristolochiaceae plants, the roots and rhizomes ofAsarum sieboldii Miq. var. seoulense Nakai, the fruits ofAristolochia contorta Bunge or A. debilis Sieb. et Zucc., the roots ofAristolochia debilis Sieb. et Zucc., the stems ofAristolochia manshuriensis Kom., and the roots of Aristolochiafangchi Y. C. Wu ex L. D. Chou et S. M. Hwang. A total of five AAs and three ALs were identified by co-chromatography of sample extract and comparing the retention time, UV spectra, and characteristic molecular ions and fragment ions with those of authentic standards, or tentatively identified by MS/MS determination along with Mass Fragment software. Moreover, the method was validated for the simultaneous quantification or semi-quantification of them. The samples significantly differed in the quality and quantity of AA analogues, which aUowed the possibility of showing their chemical distinctness, and it might be helpful in their standardization and quality control. Furthermore, in order to holistically compare the difference between the five Aristolochiaceae plants, dataset obtained from UHPLC-Q/TOF-MS was processed with principal component analysis (PCA) and orthogonal partial least squared discriminant analysis (OPLS-DA). 展开更多
关键词 Aristolochic acids Aristololactams ARISTOLOCHIACEAE UHPLC-Q/TOF-MS Quantification Multivariate statistical analysis
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