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11.
Ultra-performance liquid chromatography/time-of-flight mass spectrometry based metabolomics of raw and steamed Panax notoginseng 总被引:4,自引:0,他引:4
Chan EC Yap SL Lau AJ Leow PC Toh DF Koh HL 《Rapid communications in mass spectrometry : RCM》2007,21(4):519-528
At present, metabolite profiling is of growing importance in herbal medicine fields such as breeding, formulation, quality control and clinical trials. This preliminary study indicated that ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC/TOFMS)-based metabolomics allows direct detection of down-stream derivatives of metabolites, arising from the herbal formulation process. This analytical approach allows the discrimination and tentative authentication of unique biomarkers related to different herbal extracts using unsupervised multivariate principal component analysis (PCA). The tentative identification of biomarkers is complemented significantly by the accurate mass measurement of TOFMS and the high resolution and high retention time reproducibility rendered by UPLC. The application of this approach in herbal extract discrimination and ginsenoside biomarker discovery of raw and steamed Panax notoginseng (Burk.) F.H. Chen is demonstrated and discussed. 相似文献
12.
Guanglu Zhou Kim-Chuan Toh Gongyun Zhao 《Computational Optimization and Applications》2004,27(3):269-283
Most existing interior-point methods for a linear complementarity problem (LCP) require the existence of a strictly feasible point to guarantee that the iterates are bounded. Based on a regularized central path, we present an infeasible interior-point algorithm for LCPs without requiring the strict feasibility condition. The iterates generated by the algorithm are bounded when the problem is a P
* LCP and has a solution. Moreover, when the problem is a monotone LCP and has a solution, we prove that the convergence rate is globally linear and it achieves `-feasibility and `-complementarity in at most O(n
2 ln(1/`)) iterations with a properly chosen starting point. 相似文献
13.
Iridium‐ and Osmium‐decorated Reduced Graphenes as Promising Catalysts for Hydrogen Evolution 下载免费PDF全文
Chee Shan Lim Prof. Zdeněk Sofer Rou Jun Toh Alex Yong Sheng Eng Jan Luxa Prof. Martin Pumera 《Chemphyschem》2015,16(9):1898-1905
Renewable energy sources are highly sought after as a result of numerous worldwide problems concerning the environment and the shortage of energy. Currently, the focus in the field is on the development of catalysts that are able to provide water splitting catalysis and energy storage for the hydrogen evolution reaction (HER). While platinum is an excellent material for HER catalysis, it is costly and rare. In this work, we investigated the electrocatalytic abilities of various graphene–metal hybrids to replace platinum for the HER. The graphene materials were doped with 4f metals, namely, iridium, osmium, platinum and rhenium, as well as 3d metals, namely, cobalt, iron and manganese. We discovered that a few hybrids, in particular iridium‐ and osmium‐doped graphenes, have the potential to become competent electrocatalysts owing to their low costs and—more importantly—to their promising electrochemical performances towards the HER. One of the more noteworthy observations of this work is the superiority of these two hybrids over MoS2, a well‐known electrocatalyst for the HER. 相似文献
14.
HUA Wei ZHOU Xiao-Hong ZHANG Yu-Hu GUO Ying-Xiang Oshima M. Toh Y. Koizumi M. Osa A. Hatsukawa Y. QI Bin ZHANG Shuang-Quan MENG Jie Sugawara M. 《中国物理C(英文版)》2009,33(9)
High-spin levels of 189Pt have been studied with the in-beam γ-spectroscopy method via the 176Yb(18O,5n) reaction at the beam energies of 88 and 95 MeV. The previously known vi13/2-1 band has been confirmed, and its unfavored signature branch extended up to the 31/2+ state. Within the framework of the triaxial particle-rotor model, the vi13/2-1 band is suggested to be associated with the 11/2[615] configuration, and to have triaxial deformation. 相似文献
15.
宋立涛 周小红 郭应祥 孙志宇 M.Oshima T.Toh A.Osa M.Koizumi J.Katakura Y.Hatsukawa M.Matsuda M.Sugawara 《中国物理 C》2004,28(2):148-151
利用能量为164—180MeV的35Cl束流,通过重离子核反应149Sm(35Cl,5n)研究了179Au的高自旋态能级结构.实验进行了γ射线的激发函数、X-γ和γ-γ-t符合测量.基于对实验测量结果的分析,首次建立了179Au的1/2[660](πi13/2)转动带.结合已有的实验数据,着重讨论了奇AAu核中1/2[660](πi13/2)转动带的带头激发能随中子数的变化 相似文献
16.
17.
In this paper we derive the Integration-by-Parts Formula using the generalized Riemann approach to stochastic integrals, which
is called the Ito-Kurzweil-Henstock integral. 相似文献
18.
应用E-GOS(E-Gamma Over Spin)曲线方法研究了A≈110质量区奇A核结构随角动量增加的演化, 发现随着角动量的增加原子核的激发特性从振动逐渐演化为转动。 The E-GOS(E-Gamma Over Spin)curves were used to investigate the structure evolution in the odd A nuclei around A≈110 as a function of spin. The result shows that there is a clear transition from vibration to rotation while increasing spin. 相似文献
19.
Yew Hoong Leong Jaguthsing Dindyal Tin Lam Toh Khiok Seng Quek Eng Guan Tay Sieu Tee Lou 《ZDM》2011,43(6-7):819-831
Problem solving is at the heart of the Singapore Mathematics curriculum. However, it remains a challenge for teachers to realise this curricular goal in practice. Here, we review the efforts of Singapore mathematics teacher educators in incorporating problem-solving (teaching) competency in teacher education and PD programmes. We discuss conceptual and practical issues, actions taken and changes made in building teachers?? capacity to enact a problem-solving curriculum in a school-based design experiment project. In the project, teachers learnt problem solving, observed and then carried out lessons, using the ??Mathematics Practical????akin to the science practical??as key to instruction and assessment. 相似文献
20.
Fang YongDe Zhang YuHu Oshima M. Toh Y. Xu FuRong Shi Yue Zhou XiaoHong Liu MinLiang Guo YingXiang Koizumi M. Kimura A. Hatsukawa Y. Morikawa T. Nakamura M. Sugaware M. Kusakari H. 《中国科学:物理学 力学 天文学(英文版)》2011,54(1):98-102
A new rotational band has been identified and assigned to 188Au for the first time using the 173Yb(19F,4nγ) reaction at the beam energies of 86 and 90 MeV. This band is proposed to be built on the πh 9/2 ⊗ νi 13/2 configuration by comparing the band properties with known bands in neighboring nuclei. The prolate-to-oblate shape transition through triaxial shape has been proposed to occur around 188Au for the ηh 9/2 ⊗ νi 13/2 bands in odd-odd Au isotopes on the basis of total Routhian surface (TRS) calculations.
相似文献