Comparative analysis in different organs and tissue-specific metabolite profiling of Atractylodes lancea from four regions by GC–MS and laser microdissection

Traditional Chinese medicine is made from the rhizome of Atractylodes lancea (Thunb.) DC. (Compositae), known as Cangzhu. In this study, gas chromatography-mass spectrometry was used to identify and quantify the volatile oils of different organs of A. lancea from four regions of China: Jiangsu, Anhui, Henan, and Hubei provinces. The volatile oils of A. lancea were qualitatively and quantitatively characterized using gas chromatography-mass spectrometry combined with laser microdissection. The results identified 21 components in A. lancea, the majority of the components were found in the rhizomes, followed by the fibrous roots, flowers, leaves, and stems. According to the contents of volatile oils in A. lancea, it was divided into Dabieshan (mainly includes hinesol and β-eudesmol) and Maoshan types (mainly includes atractylon and atractylodin), and the ratios of hinesol:β-eudesmol:atractylon:atractylodin were 17.06:4.55:0:1, 12.66:11.71:0.99:1, 7.43:6.23:0:1, and 0.13:0.16:1.52:1 in A. lancea from AH, HN, HB, and JS, respectively. Tissue-specific study indicated that Dabieshan type mainly includes elemol, hinesol, and β-eudesmol in the periderm and secretory cavities of A. lancea, whereas Maoshan type mainly includes atractylon, atractylodin, little hinesol, and β-eudesmol in the secretory cavities. Conversely, no volatile oils were detected in the cortex, phloem, xylem, vascular ray, or pith. This study provides a foundation for further evaluation and utilization of A. lancea.     

Hydrogen production by ethanol steam reforming over Ni-doped LaNixCo1−xO3−δ perovskites prepared by EDTA-citric acid sol–gel method

Journal of Sol-Gel Science and Technology - Achieving efficient and stable hydrogen production has always been the focus of the industry, and ethanol steam reforming (ESR) is one of the most...     

Analysis of a Monod–Haldene type food chain chemostat with seasonally variably pulsed input and washout

In this paper, we introduce and study a model of a Monod–Haldene type food chain chemostat with seasonally variably pulsed input and washout. We investigate the subsystem with substrate and prey and study the stability of the periodic solutions, which are the boundary periodic solutions of the system. The stability analysis of the boundary periodic solution yields an invasion threshold. By use of standard techniques of bifurcation theory, we prove that above this threshold there are periodic oscillations in substrate, prey and predator. Simple cycles may give way to chaos in a cascade of period-doubling bifurcations. Furthermore, bifurcation diagrams have shown that there exists complexity for the pulsed system including periodic doubling cascade, periodic halving cascade and Pitchfork bifurcations and tangent bifurcations.      

Study of Lotka-volterra food chain chemostat with periodically varying dilution rate

In this paper, we introduce and study a model of Lotka-volterra chemostat food chain chemostat with periodically varying dilution rate, which contains with predator, prey, and substrate. We investigate the subsystem with substrate and prey and study the stability of the periodic solutions, which are the boundary periodic solutions of the system. The stability analysis of the boundary periodic solution yields an invasion threshold. By use of standard techniques of bifurcation theory, we prove that above this threshold there are periodic oscillations in substrate, prey, and predator. Simple cycles may give way to chaos in a cascade of period-doubling bifurcations. Furthermore, we numerically simulate a model with sinusoidal dilution rate, by comparing bifurcation diagrams with different bifurcation parameters, we can see that the system experiences following process: periodic solution → periodic doubling cascade → chaos.     

各种运输方式客运质量的综合评价研究

在建立各种运输方式客运质量综合评价指标体系的基础上,提出了用于各种运输方式客运质量综合评价的方法——"专家法—信息熵—灰色关联投影法"相结合的组合评价模型,该模型将专家法、信息熵理论和灰色关联决策法有机结合起来.最后根据实际数据对各种运输方式的客运质量加以综合评价并排序比较,验证该方法的合理性和有效可行性.     

一类广义锥类凸映射

借助于所谓的寻址和存储理论中的有关(σ,S)策略的最优性问题,在拓扑向量空间序锥的意义下引入一类广义锥类凸映射,讨论这类映射的若干性质,并给出它的一些刻画.     

A comparative study of the effect of the position of outliers on classical and nontraditional approaches to the two-group classification problem

Popularity of nontraditional approaches to the statistical classification problem has resulted from the potential of these techniques to outperform the standard parametric procedures under conditions when nonnormality is present. Thus proponents of these nontraditional models have recommended these models when outliers are in the data. However, research showing that these nontraditional models' performances can vary widely depending on where the outlier data are located has not been fully illustrated. The research in this paper demonstrates how the mathematical programming approaches and the nearest neighbor discriminant models can be affected by the position of contaminated normal data and that each of the models studied in this paper may not be robust to all types of outliers in the data. The results of this paper are also important because the study compares two recently proposed mathematical programming models as well as two versions of the nearest neighbor model with the standard classical parametric models. This combination of classification models does not appear to have been studied together under conditions of contaminated normal data in which numerous positions of the outliers are considered.     

Some Two-Point Resistances of the Sierpinski Gasket Network

In this paper, we use the principle of substitution to replace sub-gaskets of the Sierpinski gasket network by an equivalent Y-network which enables the use of only the Delta–Wye transformation and the series and parallel principles to derive some two-point resistances of the Sierpinski gasket network with dimension two.     

铝基复合材料超精密加工中的刀-屑摩擦磨损性能及模型研究

通过金刚石PCD刀具对非连续SiC增强铝基复合材料的超精密车削加工试验,考察了刀具第二切削变形区(刀具前刀面-切屑间)的摩擦磨损性能,并提出了相应的模型;采用爆炸式快速落刀装置制备出切屑根并分析了积屑瘤的影响因素;采用原子力显微镜对PCD刀具的刃口磨损形貌进行观察,并分析其磨损机理.结果表明:在超精密切削加工非连续增强铝基复合材料的过程中,前刀面仍然有极小的楔型积屑瘤产生;铝基复合材料的摩擦磨损性能明显优于铝合金,且当SiC增强相达到最佳体积分数(20%～25%)时,其摩擦磨损性能最佳;从刀具的耐磨性角度考虑,在超精密加工非连续增强铝基复合材料时适宜采用金刚石刀具.     

Geographical networks: geographical effects on network properties

Complex networks describe a wide range of systems in nature and society. Since most real systems exist in certain physical space and the distance between the nodes has influence on the connections, it is helpful to study geographical complex networks and to investigate how the geographical constrains on the connections affect the network properties. In this paper, we briefly review our recent progress on geographical complex networks with respect of statistics, modelling, robustness, and synchronizability. It has been shown that the geographical constrains tend to make the network less robust and less synchronizable. Synchronization on random networks and clustered networks is also studied.