论广西民族装饰纹样中的吉祥观念

从广西民族装饰纹样的分类和特点出发,举例说明了广西的民族装饰纹样中体现的各种吉祥观念,并对广西民族装饰纹样中的吉祥观念的未来发展作出预测。认为吉祥观念是人类普遍存在的心理意识,它被人们借以各类载体表达和呈现,其中以民族装饰为吉祥观念的最主要载体。     

Data-driven estimation of diurnal patterns of durations between trades on financial markets

We propose a data-driven local linear estimator for diurnal patterns of transaction durations with a brief discussion on its asymptotics. The standardized durations are modeled by the EACD. Codes in R are developed for practical implementation. Application is illustrated by data examples.     

以自适应对象模型开发自适应软件

自适应对象模型方法是一种开发动态的和可配置的自适应软件的有效途径,具有元模型、描述驱动和运行时反射等特点。介绍了当前自适应软件的研究现状,剖析了以自适应对象模型开发自适应软件的方法。首先阐述了自适应对象模型的核心思想,然后分析自适应对象模型体系结构中建立元模型的5个模式,以及模型引擎和支撑工具,并讨论了自适应对象模型方法的适用时机、优缺点和实现中的问题。最后,与相关的技术进行了综合对比,讨论了未来的研究方向。     

Mechanical effects of the self-organization of dislocations and related critical characteristics

The effects of the dislocation pattern formed due to the self-organization of the dislocations in crystals on the macroscopic hardening and dynamic internal friction (DIF) during deformation are studied. The classic dislocation models for the hardening and DIF corresponding to the homogeneous dislocation configuration are extended to the case for the non-homogeneous one. In addition, using the result of dislocation patterning deduced from the non-linear dislocation dynamics model for single slip, the correlation between the dislocation pattern and hardening as well as DIF is obtained. It is shown that in the case of the tension with a constant strain rate, the bifurcation point of dislocation patterning corresponds to the turning point in the stress versus strain and DIF versus strain curves. This result along with the critical characteristics of the macroscopic behavior near the bifurcation point is microscopically and macroscopically in agreement with the experimental findings on mono-crystalline pure aluminum at temperatures around 0.5T _m . The present study suggests that measuring the DIF would be a sensitive and useful mechanical means in order to study the critical phenomenon of materials during deformation. The project supported by the National Natural Science Foundation of China under the Grand 19702019 & 19891180-4 and by the Chinese Academy of Sciences under the Grand KJ951-1-201.     

Spatial patterns of ephemeral plants in Gurbantünggüt Desert

In the present research, the authors measured parameters of richness, cover and importance value of ephemeral and ephemeroid plants on south-north and east-west transects in the Gurbantünggüt Desert in early spring, and investigated and analyzed the microhabitats, such as terrain, geomorphology, soil physical-chemical properties and crusts. By comparison, the regional differences in the ephemeral distribution in the desert were revealed. The species of ephemeral plants in the south and center are the richest and those in the west are the poorest in the desert. The cover of ephemeral plants in the mid-south is higher than that in the north, and that in the mid-east is higher than that in the west. The response of ephemeral plants to the spatial variation of the desert habitat forms the population-habitst gradient of ephemeral plants. The characteristics are： （1） In the habitat with higher terrain, coarser textured soil with poorer sorting and correspondingly higher organic matter and lower alkali-saline contents, Carex physoides and Eremopyrum orientale are the dominant ephemeral plants; （2） In the dry habitat with lower terrain, looser textured soil, some organic matter, alkali-saline soil, and developed crust, the ephemeral plants Alyssum linifolium and Erodium oxyrrhynchum are of characteristic of drought and alkali-saline tolerance; （3） In the habitat with lower terrain, some water and more alkali-saline soil, the ephemeral plants Neotorularia torulosa and Hypecoum parviflorum being of alkali-saline tolerance are mainly developed. However, most ephemerals are distributed in a habitat order of higher terrain, some organic, and less alkali-saline soil on the above-mentioned ephemeral population-habitst gradient. The spatial gradient of variation in desert microhabitsts is small, and as a whole, the physiological character of mesophytism is represented by the desert ephemerals.     

Structural distortions of semiconducting silicon crystals caused by constant electric field

Structural distortions in nonpolar, particularly, in semiconducting silicon crystals, caused by constant electric field have been disclosed by means of X‐ray interferometry. It was shown that in the field both the direction of moiré fringes and the frequency (period) are changed, and the moiré patterns disappear at values of potential difference in excess of 1.5 kV. The moiré pattern obtained under the action of electrostatic field is independent of the direction (polarity) of the field, the pictures for both the polarities being completely identical. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Laser singular Theta-pinch

The interaction of the two counter-propagating ultrashort laser pulses with singular wavefronts in the thin slice of the underdense plasma is considered. It is shown that ion-acoustic wave is excited via Brillouin three-wave resonance by corkscrew interference pattern of paraxial singular laser beams. The orbital angular momentum carried by light is transferred to plasma ion-acoustic vortex. The rotation of the density perturbations of electron fluid is the cause of helical current which produces the kilogauss axial quasi-static magnetic field. The exact analytical configurations are presented for an ion-acoustic current field and magnetic induction. The range of experimentally accessible parameters is evaluated.     

Flow waves of hierarchical pattern formation induced by chemical waves: The birth, growth and death of hydrodynamic structures

We introduce a short review of chemically driven convection together with a series of our experiments on hydrodynamic instabilities induced by chemical waves excited in the batch reactor of a Belousov-Zhabotinsky reaction. Several unresolved phenomena are picked out and possible mechanisms are discussed extensively. Interesting features of these phenomena can be summarized as being caused by the ‘global and dynamic hydrodynamic pattern induced by chemical waves’. These chemically induced global pattern of hydrodynamic phenomena may not be simply explained by the reaction-diffusion-convection model based on Marangoni instability (surface tension-driven convection), which produces only a localized structure of the convection pattern. Observed flow waves show global and dynamic patterns of convection that generate a functional structure associated with hierarchical patterns appearing in the reaction-diffusion-convection system. In particular, we clarify the existence of a continuous stream of hydrodynamic flow with growing amplitude and its rotating direction. We find that the flow does not stabilize to a motionless state until the system has self-collapsed. This new picture of the flow waves requires a revision of the reaction-diffusion-convection model. The established flow structure can be regarded as a mixing and/or transport process to supply the substrate from the peripheral region to the centre of the chemical waves to sustain the reaction. This characteristic may be a function of the hierarchical structure. A new mechanism for the viscous-elastic feature of the gas-liquid interface is discussed in order to understand these curious phenomena of interest.     

In quest of a systematic framework for unifying and defining nanoscience

This article proposes a systematic framework for unifying and defining nanoscience based on historic first principles and step logic that led to a “central paradigm” (i.e., unifying framework) for traditional elemental/small-molecule chemistry. As such, a Nanomaterials classification roadmap is proposed, which divides all nanomatter into Category I: discrete, well-defined and Category II: statistical, undefined nanoparticles. We consider only Category I, well-defined nanoparticles which are >90% monodisperse as a function of Critical Nanoscale Design Parameters (CNDPs) defined according to: (a) size, (b) shape, (c) surface chemistry, (d) flexibility, and (e) elemental composition. Classified as either hard (H) (i.e., inorganic-based) or soft (S) (i.e., organic-based) categories, these nanoparticles were found to manifest pervasive atom mimicry features that included: (1) a dominance of zero-dimensional (0D) core–shell nanoarchitectures, (2) the ability to self-assemble or chemically bond as discrete, quantized nanounits, and (3) exhibited well-defined nanoscale valencies and stoichiometries reminiscent of atom-based elements. These discrete nanoparticle categories are referred to as hard or soft particle nanoelements. Many examples describing chemical bonding/assembly of these nanoelements have been reported in the literature. We refer to these hard:hard (H-n:H-n), soft:soft (S-n:S-n), or hard:soft (H-n:S-n) nanoelement combinations as nanocompounds. Due to their quantized features, many nanoelement and nanocompound categories are reported to exhibit well-defined nanoperiodic property patterns. These periodic property patterns are dependent on their quantized nanofeatures (CNDPs) and dramatically influence intrinsic physicochemical properties (i.e., melting points, reactivity/self-assembly, sterics, and nanoencapsulation), as well as important functional/performance properties (i.e., magnetic, photonic, electronic, and toxicologic properties). We propose this perspective as a modest first step toward more clearly defining synthetic nanochemistry as well as providing a systematic framework for unifying nanoscience. With further progress, one should anticipate the evolution of future nanoperiodic table(s) suitable for predicting important risk/benefit boundaries in the field of nanoscience. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.