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1.
《中国物理 B》2014,(9):622-622
Chinese Physics B(Chin.Plivs.B).formerly titled Chinese Physics,is an international compreliensive academic journal,aiming to publish original papers and rapid communications reflecting creative and innovative achievements in physics,as well review papers about important accomplishments in frontier of physics.The journal is published monthly in English by the Chinese Physical Society(CPS)and the IOP Publishing.Chin.  相似文献   
2.
Jiang  Jun  Xu  Jian-Xue 《Nonlinear dynamics》1998,15(2):103-114
In iterative method of Point Mapping under Cell Reference, a cell co-ordinate system, called cell reference, is built to identify the subregions (cells) in the state space. When the cell reference is equipped with the so-called characteristic functions, it can work as an inspector or a recorder to derive the local dynamics of the subregions from the information provided by the trajectories passing through them. This method can retain the accuracy of the Point Mapping Method but greatly reduce the computational work. In this paper, the theoretic basis for this method is first discussed and a multiscale reference technique is then devised which can select an optimal cell reference and make the method more practicable. Finally, an example for application is presented. It is shown that the present method cannot only accurately and efficiently depict the basins of attraction of a dynamical system but also potentially detect other characteristics of the system.  相似文献   
3.
In geological samples, Se concentration ranges from 1 × 10−9 g g−1 up to 1 × 10−3 g g−1. The analytical difficulty at low concentration (<1 μg g−1), is one of the main reasons why the geological cycle of Se is poorly known. The analytical method that consisted of preconcentration of Se with thiol cotton fiber (TCF) followed by graphite furnace atomic absorption spectrometry (GFAAS) has been modified by finishing with instrumental neutron activation analysis (INAA). The modified technique involves sample dissolution (HF-HNO3-H2O2) and evaporation to dryness at low temperature (55-60 °C) to avoid selenium volatilization. SeVI is converted to SeIV by adding 6 M HCl to the dry residuum and the solution is then heated in a covered boiling bath (95-100 °C). The solution is diluted to obtain 0.6 M HCl and then collected on TCF. The TCF is placed in a polyethylene vial for irradiation in the SLOWPOKE II reactor (Montréal) for 30 s at a neutron flux of 1015 m−2 s−1. The 162 keV peak of 77mSe (half-life 17.36 s) is read for 20 s after a decay of 7 s. The amount of sample to be dissolved is controlled by two competing effects. To obtain low detection limits, a larger amount of sample should be dissolved. On the other hand, the TCF could become saturated with chalcophile elements when large sample is used. Sulfur is a good indicator of the amount of Se and chalcophile elements present. In S poor sample (<100 μg g−1) 3.0 g of sample was used and the LD was ∼2 ng g−1. In S high samples (>1.5% S) 0.05 g of sample was used and the LD was ∼120 ng g−1. The present work also includes suggested Se concentration for eight international geological reference materials (IGRM) that compare favorably with literature values.  相似文献   
4.
In order to prove up the interaction between konjac glucomannan (KGM) and other amyloses, by using KGM, guaran gum and carrageenan as materials, their blending in different external conditions was modeled by means of molecular dynamics (MD) method. The result showed that 323 K was a significant turning point for the formation of hydrogen bond, and KGM and guaran gum were just juxtaposed together via intermolecular hydrogen bond; but with the addition of carrageenan, KGM, guaran gum and carrageenan were spirally twisted together, and when their blending proportion is 3:2:9 the combination was the most compact. Moreover, the research result has provided the sequent studies afterwards on amyloses with some references.  相似文献   
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Traceability is now considered to be a key concept in chemical and biological measurement sciences. While this concept is increasingly used in many areas, it is still prone to misunderstandings with respect to more ‘classical' terms such as e.g. accuracy. Traceability implies that measurement data are linked to stated references through an unbroken chain of comparisons, all with stated uncertainties. What does the word ‘stated references' mean when it is applied to complex environmental analysis? This paper discusses how traceability can be conceived in the context of environmental monitoring, in particular the various stated references (documented standards, reference materials, environmental specimens) to which chemical environmental data may be linked to.  相似文献   
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8.
Residual amplitude modulation (RAM) distorts saturated absorption signals, limiting the accuracy of optical frequency references based on modulation transfer spectroscopy (MTS). Described here are two independent means by which RAM is produced in these references: (1) by the modulator and (2) when the overlap of the optical fields in the saturable absorber is asymmetric. Methods to vary RAM generated by either mechanism will be outlined and these will be used to show how RAM arising from one effect can be cancelled by the other. A theoretical treatment of MTS signals in references containing RAM is given and used to evaluate the level of signal distortion allowing the conditions for RAM cancellation to be determined. This technique is applied to improve the frequency accuracy of a reference by an order of magnitude.  相似文献   
9.
正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with  相似文献   
10.
邢景棠 《力学季刊》2021,42(3):413-428
本文给出了详尽的格子玻尔兹曼方法的概述:包含其理论基础、起源、基本思想及主要特征,历史进展、重要的综述、著名书刊、应用及可用计算机代码,从而为从事有关研究的学生与研究人员提供了丰富的参考文献. 通过文献检索阅读, 揭示了以下有待探讨的理论问题: (a) 麦克斯韦-玻尔兹曼分布(Maxwell-Boltzmann distribution)的建立只涉及稀薄气体的压力内能,但未考虑粘性应力的内能;(b) 三个守恒律无法从玻尔兹曼方程直接导出,必须借助外加的小参数展开完成,同时在守恒方程中无法引入外力及能源的贡献;(c) Lattice Boltzmann Method (LBM)执行中,只更新流体的物质密度和平均速度,不更新其内能参数.由于在复杂流动中,流体的内能是时间及空间的函数,因此其理论是不完整的.以上揭示的理论问题是现有LBM方法 不能有效地求解涉及高速及大压缩性引起内能剧烈变化的复杂流场的原因.作者给出一篇理论研究文章以回答揭示的理论问题.  相似文献   
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