Symmetry in halo displays and symmetry in halo-making crystals

The relation between the symmetry in halo displays and crystal symmetry is investigated for halo displays that are generated by ensembles of crystals. It is found that, regardless of the symmetry of the constituent crystals, such displays are always left-right (L-R) symmetric if the crystals are formed from the surrounding vapor. L-R symmetry of a halo display implies here that the cross sections for formation of a halo arc on the left-hand side of the solar vertical and its right-hand side mirror image are equal. This property leaves room for two types of halo display only: a full symmetric one (mmm-symmetric), and a partial symmetric one (mm2-symmetric) in which halo constituents lack their counterparts on the other side of the parhelic circle. A partial symmetric display can occur only for point halos. Its occurrence implies that a number of symmetry elements are not present in the shape of the halo-making crystals. These elements are a center of inversion, any rotatory-inversion axis that is parallel to the crystal spin axis P, a mirror plane perpendicular to the P axis, and a twofold rotation axis perpendicular to the P axis. A simple conceptual method is presented to reconstruct possible shapes of the halo-generating crystals from the halos in the display. The method is illustrated in two examples. Halos that may occur on the Saturnian satellite Titan are discussed. The possibilities for the Huygens probe to detect these halos during its descent through the Titan clouds in 2005 are detailed.     

人工智能艺术设计光晕的持续

对人工智能艺术设计光晕的持续条件标准进行分析。以人工智能艺术家的合法身份与艺术设计作品的标准来探讨,发现了人工智能艺术设计具有持续性的“光晕”。人工智能因机械成为“生产主体”并获得了合法的社会身份,成为了文化智能生产中新的“主体”。智能主体所生产的艺术品已经不单是某种原件的原生命力的再现,在狭义的范畴上,其作品是某个艺术家或设计师观念风格的延续,而在广义的范畴上,是人类文明意识的再造,只有远离糟粕、虚伪、丑恶、异化,才能具有如希腊艺术品一样崇高的膜拜价值和形象的魔力。“真”、“善”、“美”依旧是评价人工智能艺术设计作品是否具有“光晕”的标准。由人工智能生产的作品因其机械性地原创了艺术的物质与观念部分,使其具有了“原真性”,而要想通过“善”赋“魂”,则要在数据和伊始的算法设计上构建“善”的设计约规,形成人文关怀和实现阶层的善用。人工智能艺术设计品是人类精神的集体显现,如同折光镜一般,持续折射人类艺术设计理想的“光晕”。     

Thirty years of observing and documenting sky optical phenomena

A homogeneous series of systematic observations of sky optical phenomena in the Netherlands has been gathered by the Dutch Observing Network since 1965. This continues the Dutch observation series that started at the end of the nineteenth century. A time series of ice-crystal halo frequencies from 1920 to 1996 and frequency diagrams of some specific halos the period from 1970 to 1996 are shown and discussed. Systematic observation recording by means of diaries and exchanging routines among observers are described. Methods are given for establishing and maintaining a network of volunteers that can provide, in a homogeneous time series, sky optical phenomena recordings.     

中国书法在日本包装中的应用

以书法艺术在现实生活中的文字信息传播功能与抽象的民族艺术符号为启示,分析了中国书法艺术蕴含的文化性、民族性、艺术性的多样统一,结合日本包装设计中书法的运用实践,论述了书法艺术在日本包装设计风格中的应用形式与价值体现。继而提出了书法艺术是特殊的图形符号,应结合西方先进的设计形式和设计理念,让书法艺术与中国包装设计彼此互衬、相交辉印,从而赋予包装极高的艺术审美性。     

Crystals of hexagonal ice with (2 0 2 3) Miller index faces explain exotic arcs in the Lascar halo display

This article focuses on the 1997 Lascar halo display, during which very unusual arcs and halos were documented. Photographs have been analyzed with the aid of a specific image processing method developed by us. Using crystals of hexagonal ice with exotic (2 0 2 3) Miller index faces, it is possible to simulate all the features of the display with constant crystal populations and oriented crystals in plate orientation. The simulations perform better than the cubic ice explanation. The existence of (2 0 2 3) crystal faces is supported by a 1998 South Pole halo display.     

Three-dimensional imaging with simultaneous reproduction of two image elements in one display pixel by linearization of intensity ratio of two images formed by any physical gear

Full spatial resolution in stereo image is reached if each (left and right) view of a three-dimensional scene is reproduced by all pixels of the display matrix. It is attractive for this purpose to simultaneously reproduce two image resolvable elements (corresponding to image elements of left and right views) in one display pixel. This paper shows how information-dependent linearization of the optical intensity ratio of left and right image elements (whose sum is submitted in the form of common optical intensity on the input of the display pixel) can be used to present corresponding elements separately in left and right observation windows. Such a linearization principle is valid regardless of the concrete physical gear of optical separation and demonstrated on the examples of optical separators on the basis of polarization, spectral, diffractive, and real amplitude modulation of light.     

摄影作品在设计中的应用研究

目的探究摄影作品在艺术设计中的应用方式。方法结合艺术设计学、美术学、广告学、传播学理论知识,采用案例分析法、观察研究法、归纳法等方法,归纳艺术设计中摄影作品的具体处理手法。结论摄影与艺术设计的融合是现代艺术设计的创意灵魂,既符合消费者的审美求,又蕴藏有巨大的商业价值,对于现代艺术设计具有重要的指导意义。     

Halo polarization profiles and sampled ice crystals: observations and interpretation

Simultaneous two-wavelength polarization and radiance distributions have been obtained for 22 degrees parhelia in four Antarctic ice-crystal swarms that extended to ground level. Samples of crystals that produced these parhelia were collected and replicated. The wavelength dependence of the width of the halo polarization peak agrees with Fraunhofer diffraction theory, indicating that the broadening of the halos is caused primarily by diffraction. However, the observed broadening is much more than predicted from the size distribution of the replicated crystals. From one halo display to the other, the ratio of observed/predicted broadening is erratic, suggesting size-dependent collection efficiency in the sampling. This would imply that, for South Pole conditions, halo polarimetry (or even photometry) is a more reliable method for crystal size determination than actual sampling. It also implies that shapes of the sampled crystals need not necessarily be representative for the shapes of the halo-making crystals in the swarm. Our previous hypothesis [Appl. Opt. 33,4569 (1994)], that a spread of interfacial angles is the dominating cause of halo broadening, has proved untenable.     

Complex spatio-temporal dynamics of optical parametric oscillators close to threshold

Abstract

Spatially extended degenerate cw optical parametric oscillators are predicted to display a rich variety of spatio-temporal dynamic behaviour in two transverse dimensions. Typical examples are the dynamical scaling of phase domains, randomly distributed cavity solitons, formation of spatial patterns and optical turbulence. In spite of recent encouraging experimental results, many of these features can be difficult to observe in real devices since they require input energies which are too large. Here we show that in the case of a higher finesse for the pump field than for the signal field, complex spatio-temporal phenomena move closer to the signal generation threshold thus making their experimental observation more feasible.     

农耕印迹:扎染菱形纹样作为布依语“Ndaeh Sengh”的解读研究

目的 菱形纹样是我国古老的几何纹样之一,其历史悠久、应用广泛,在不同地域和文化背景下被赋予了不同的文化内涵,厘清纹样的在地性符号所指,是提升传统工艺传承与设计创新的方法路径。方法 以贵州花戛乡布依族扎染技艺中的菱形纹样为研究个案,结合人类学的田野调查法和艺术设计学的比较研究法,对花戛布依族服装配饰中的扎染菱形纹样进行综合考证和分析。结论 认为花戛扎染菱形纹样是布依族日用器物“升”的形态转译,是农耕背景下布依人祈求丰收的文化符号载体。有着文化符号功能的菱形“Ndaeh Sengh”纹样,与布依人生活、习俗、地域环境等方面存在多维的联结,“Ndaeh Sengh”越多代表农作物收成越好,寓意丰收和富足。“Ndaeh Sengh”作为农耕记忆背景下布依族集体无意识原型形式的外化,其制作工艺和纹样所承载的文化记忆对于非遗保护、工艺传承、非遗设计等方面都有一定的理论指导意义。     

解读现代标志中的民族艺术元素

针对现代标志设计中融入民族艺术元素这一发展潮流,通过解读经典现代标志,总结分析现代标志设计中融入民族艺术精髓是现代社会文化艺术和经济发展的需求,它不但对现代标志设计的发展具有重要意义和价值,而且对我国的经济和文化、精神文明的发展,构建和谐社会都起到巨大的推动作用.     

Halo Observations Provide Evidence of Airborne Cubic Ice in the Earth's Atmosphere

An ice crystal halo display that contains several previously unknown halo phenomena was observed in Northern Chile. Analysis of computer simulations of the halos demonstrates that most of the new halo arcs in the display can be explained by the presence of airborne and preferentially oriented crystals of cubic ice. These observations therefore provide evidence of the existence of the cubic phase of ice in the Earth's atmosphere.     

Approach to photorealistic halo simulations

A multiple-scattering Monte Carlo model that can produce near-photographic quality images is developed and used to simulate several dramatic halo displays. The model atmosphere contains an absorbing ozone layer plus two clear, molecular air layers with Rayleigh scattering surrounding a cloud layer and an atmospheric boundary layer with aerosol particles subject to Lorentz-Mie scattering. Halos are produced by right hexagonal or pyramidal crystals that reflect and refract according to geometric optics without diffraction, although "junk" crystals with a pronounced forward-scattering peak but no halo peaks may be included to simulate typical, faint halos. Model parameters include ozone height and content, surface and cloud pressure, cloud optical thickness, crystal shapes, orientations and abundances, atmospheric turbidity, aerosol radius, and albedo. Beams for each wavelength are sorted into small bins as halo beams if they have been scattered once only by a single crystal and otherwise as sky beams, which are smoothed and combined with the halo beams to produce images. Multiple scattering generally vitiates halos, but extremely rare halos, such as Kern's arc, can be produced if a significant fraction of crystals in optically thick clouds have identical shapes and are highly oriented. Albedo is a model by-product with potential value in climate studies.     

Design of lenses to project the image of a pupil in optical testing interferometers

When an optical surface or lens in an interferometer (Twyman-Green or Fizeau interferometer) is tested, the wave front at the pupil of the element being tested does not have the same shape as at the observation plane, because this shape changes along its propagation trajectory if the wave front is not flat or spherical. An imaging lens must then be used, as reported many times in the literature, to project the image of the pupil of the system being tested over the observation plane. This lens is especially necessary if the deviation of the wave front from sphericity is large, as in the case of testing paraboloidal or hyperboloidal surfaces. We show that the wave front at both positions does not need to have the same shape. The only condition is that the interferograms at both places be identical, which is a different condition. This leads to some considerations that should be taken into account in the optical design of such lenses.     

The radiographic edge scattering distortion

Previously described scattering based edge distortions in optical density scans obtained from a neutron radiographic knife-edge image have been here confirmed using analog Monte Carlo simulation. In an attempt to estimate the effects of additional object scatter on such artifacts, the effect on the edge response of diffusely incident neutrons has been determined both empirically and by Monte Carlo simulation. The diffuse neutron incidence has been found to diminish the relative magnitude of the distortion, offering explanation for the infrequent observation of the corresponding edge scattering halo artifacts. The potential of this edge distortion as a diagnostic indicator of the buildup factor in radiography is suggested and examined.     

万字符号的历史观照及其在标志设计中的应用

以万字符号在古今生活中所扮演的历史角色及其传达出的丰富文化内涵为启示,分析了万字符号的艺术特征、构成手法、形式美感、象征意义等方面对于现代标志设计的促进与影响。结合万字符号在现代标志设计中应用的实例进行例证,得出应以健康、科学、辩证的态度来深入挖掘传统符号与现代设计之间的平衡点与转化方式,从而为中国现代标志设计的发展提供参考和借鉴。     

Three-dimensional optical-transfer-function analysis of fiber-optical two-photon fluorescence microscopy

The three-dimensional optical transfer function is derived for analyzing the imaging performance in fiber-optical two-photon fluorescence microscopy. Two types of fiber-optical geometry are considered: The first involves a single-mode fiber for delivering a laser beam for illumination, and the second is based on the use of a single-mode fiber coupler for both illumination delivery and signal collection. It is found that in the former case the transverse and axial cutoff spatial frequencies of the three-dimensional optical transfer function are the same as those in conventional two-photon fluorescence microscopy without the use of a pinhole.However, the transverse and axial cutoff spatial frequencies in the latter case are 1.7 times as large as those in the former case. Accordingly, this feature leads to an enhanced optical sectioning effect when a fiber coupler is used, which is consistent with our recent experimental observation.     

Planar configuration for image projection

A flat panel, compact virtual image projection display is presented. It is based on a light- guided optical configuration that includes three linear holographic gratings recorded on one planar transparent substrate so as to obtain a magnified virtual image for a small input display. The principles of the projection display, unique design, and procedures for experimentally recording an actual planar configuration are presented, along with evaluation results. The results reveal that a field of view of +/-8 degrees can be readily achieved at a distance of 36 cm, making such planar configurations attractive for head-up displays.     

Halos in cirrus clouds: why are classic displays so rare?

Upper tropospheric cirrus clouds consist of hexagonal ice crystals, which geometrical ray-tracing-theory predicts should regularly produce a variety of optical phenomena such as vivid 22 degrees and 46 degrees halos. Yet, cirrus inconsistently generate such optical displays, while a class of more exotic displays are reported, albeit rarely. I review current knowledge of the cirrus cloud microphysical factors that control ice crystal shape, and hence halo/arc formation, but also appeal to halo enthusiasts to help investigate the causes of unusually complex, brilliant, or rare optical displays. Currently, a wealth of meteorological information can be tapped from the Internet to help advance our knowledge of the basic meteorological factors leading to these rare events.     

探析基于羌族传统艺术形式的产品创新设计

以羌族传统艺术为启示,分析了羌族传统艺术面临的困境及发展羌民族产业以对羌族传统艺术进行传承与发展,从羌族传统建筑艺术形式、羌族的传统艺术符号、羌族的传统民间器具艺术形式3个方面,对基于羌族传统艺术的产品创新设计进行探讨,力求通过与时代结合的有形物质载体理解和传承羌族人民的人文精神,更好地传承和发展羌族传统艺术。