多尺度植物色彩表征及其与人体响应的关系

色彩是人们对植物外观的第一印象,与植物视觉特征和人体响应关系密切,因此,对森林美景度提升和公众适宜性契合具有重要作用。结合色彩学形成的历史关键节点和1个世纪以来植物色彩的研究动态,将植物色彩研究的发展历程划分为萌芽、形成、发展和繁荣等4个阶段,并简介了各阶段的主要特点。同时,从植物器官、植物个体、植物群体(涵盖种群和群落)、整体景观等4个视觉尺度以及审美、生理与心理等3个影响层面,阐述与评价了植物色彩传达机制与人体响应关系的相关研究。在此基础上,围绕植物色彩特征提取中存在的色彩要素定量、特征因子选取、色彩量化方法等方面的不足之处,对未来研究方向进行展望,提出植物色彩尺度与公众响应关系剖析、较大尺度色彩评价因子的深入挖掘、色彩量化方法的多学科融入、公众对植物色彩响应关系综合比对、森林景观美景度提升实践等5个方向的发展趋势,以期为全面地了解植物色彩的传达机制与影响、科学地开展不同精度和尺度下的植物色彩研究提供参考。     

Biological structures as photonic objects

Spectroscopy, atomic force microscopy, X-ray analysis, and thermal conductometry were applied to specimens of molluscan shells, peacock feather barbules, and human horny tissue. These objects were found to contain ordered superstructures apparently interacting with electromagnetic and electronic waves and thereby exhibiting photonic and semiconductor properties.     

Structural color change following hydration and dehydration of iridescent mourning dove (Zenaida macroura) feathers

Dynamic changes in integumentary color occur in cases as diverse as the neurologically controlled iridiphores of cephalopod skin and the humidity-responsive cuticles of longhorn beetles. By contrast, feather colors are generally assumed to be relatively static, changing by small amounts only over periods of months. However, this assumption has rarely been tested even though structural colors of feathers are produced by ordered nanostructures that are analogous to those in the aforementioned dynamic systems. Feathers are neither innervated nor vascularized and therefore any color change must be caused by external stimuli. Thus, we here explore how feathers of iridescent mourning doves Zenaida macroura respond to a simple stimulus: addition and evaporation of water. After three rounds of experimental wetting and subsequent evaporation, iridescent feather color changed hue, became more chromatic and increased in overall reflectance by almost 50%. To understand the mechanistic basis of this change, we used electron microscopy to examine macro- and nanostructures before and after treatment. Transmission electron microscopy and transfer matrix thin-film models revealed that color is produced by thin-film interference from a single (∼335 nm) layer of keratin around the edge of feather barbules, beneath which lies a layer of air and melanosomes. After treatment, the most striking morphological difference was a twisting of colored barbules that exposed more of their surface area for reflection, explaining the observed increase in brightness. These results suggest that some plumage colors may be more malleable than previously thought, leading to new avenues for research on dynamic plumage color.     

How the white tiger lost its color,but kept its stripes

<正>The fantastic range of animal coloration is produced by pigment particles of colored material or microscopic structures in scales,bristles or feathers that give rise to brilliant iridescent colors.In mammals,except for a few exceptions involving nano-or micro-scale structural color(e.g.,the blue faces of male baboons),fur color is determined by the pigment melanin.Melanin is synthesized and stored in     

一种微距测量组织光学参数的方法

测量生物组织的光学参数是近红外光学检测(NIR)的主要任务之一,然而常规的近红外光学检测由于受扩散近似的限制,测量的距离一般大于2cm-3cm。本文从提高近红外光学检测空间分辨率的角度,设计了一种可用于测量生物组织局部、浅表光学参数的方法。通过使用光纤探针,实现了在微小光源-探测器间距时(＜1mm)测量组织光学参数。模型实验的结果表明该方法可反映生物组织中吸收系数及散射系数的变化率。     

经络腧穴的光学特性研究进展

现已成熟并仍有巨大潜力的光子学技术与热、电、磁等一起成为研究经络腧穴的热门手段,经络腧穴光学特性的探索不仅为其存在提供了客观依据,而且为其实际应用提供了生物物理学依据。总结目前用于经络腧穴研究的光学检测方法原理,重点综述了经络腧穴的超微弱发光、经脉红外辐射路线的客观显示、腧穴的红外辐射光谱及循经激光传输等方面的最新研究进展,以期对光子学手段在经络腧穴的研究上有一个全面的认识。     

Biogenic chaos: Cryptobioturbation and the work of sedimentologically friendly organisms

Biogenic chaos, from an ichnological point of view, can be defined as total bioturbation of sediment by infaunal organisms, such that the original sedimentary fabric and associated sedimentary structures are entirely destroyed. The truth, however, is that not all forms of thorough bioturbation are purely destructive. As improbable as it initially sounds, sediment can be pervasively (potentially 100%) bioturbated, and yet have suffered remarkably little distortion of the original bedding. In nature there exist many different levels of organism communities. Historically, the study of any natural system begins with the most obvious, attention-grabbing elements. Only later do the more innocuous aspects come to be discovered and appreciated. Ichnology shows a similar historical pattern. The most obvious aspects of the science, the discrete burrow or track forms, have been well studied for many years. Only recently have more subtle biogenic disturbances, such as micro borings, bacterial trails, meiofaunal burrows, infaunal tiering, etc., gained attention. Likewise, another level of bioturbation – cryptobioturbation – exists and is becoming more evident in the rock record. Owing to its diminutive and obscure nature, cryptobioturbation has not received widespread attention. As the name implies, cryptobioturbation is characteristically small in scale and exceedingly subtle in expression. What sets it apart from other forms of bioturbation, however is its tendency to preserve rather than to destroy the sediment’s primary physical structure.The fabric that results from cryptobioturbation can have significant influence on resulting permeability and porosity trends. In some systems where both cryptically bioturbated sandstone and generally unburrowed sandstone are present, mini-permeameter measurements show that numerous heterogeneities are retained in the unburrowed sandstone, resulting in a wide range of permeabilities. In contrast, cryptically bioturbated sandstone intervals show that these heterogeneities are less pronounced, and the resulting permeability curve is more uniform. The effect of cryptobioturbation does not result in enhanced permeabilities, but rather diminishes internal heterogeneities, leading to a more uniform permeability distribution.     

Third-order NLO properties of the DMF solutions of 3-D network and 2-D layered organic-metal polymers with (4, 4) grid units

Reactions of 1,1′-(1,4-butanediyl)bis-1H-benzimidazole (bbbm) with Cd(II), Ni(II), or Co(II) afford three organic-metal polymers: {[Cd(bbbm)(SO₄)(H₂O)₂]CH₃OH}_n (1), {[Ni(bbbm)₂(H₂O)₂](NO₃)₂ · 2CH₃OH · 6H₂O}_n (2) and {[Co(bbbm)₂(H₂O)₂](NO₃)₂ · 2CH₃OH · 6H₂O}_n (3). In 1, bbbm and coordinate to Cd(II) simultaneously leading to a 3-D structure. In 2 and 3, each bridging bbbm ligand links two Ni(II) or Co(II) ions forming the 2-D layered structure with (4, 4) grid units. Each (4, 4) grid unit is a 44-membered ring and constructed by four bbbm ligands acting as four sides and four Ni(II) or Co(II) ions representing four corners. Their third-order nonlinear optical (NLO) properties in DMF solution have been studied by Z-scan technique. The results show that the DMF solution of 2 possesses both the large third-order NLO absorptive and strong refractive behaviors; and 3’s shows large NLO absorptive effect and weak NLO refractive behavior. A reasonably good fit between the experimental data and the theoretical curve suggests that the experimentally obtained NLO effects are effective third-order in nature.     

湿度对堆肥理化性质的影响

水分是堆肥微生物生命活动的基础 ,也是堆肥中重要的工艺控制参数。弄清湿度对堆肥微生物及理化性质的影响 ,对于优化堆肥工艺参数、提高堆肥效率、降低投资和运行成本具有重要意义。综述了堆肥湿度研究的动态 ,指出了当前研究中存在的问题 ,并提出了未来的研究方向。大量的研究表明 ,湿度低于 4 5 %或高于 6 5 %都不利于堆肥处理。湿度太高会导致堆料的压实度增加、FAS减少、透气性能降低 ,从而导致堆体内氧气供应不足、堆肥升温困难、有机物降解速率降低、堆肥周期延长。湿度过低 ,水分会限制堆肥微生物的新陈代谢 ,导致微生物活性下降、堆肥腐熟困难。由于鼓风、散热、水蒸发等会使堆体内存在湿度的空间变异 ,也会降低堆肥效率和堆肥产品的质量。另外 ,堆肥湿度还影响堆肥的保肥能力。由各文献得出结论 ,堆肥的最佳湿度范围一般为 5 0 %～ 6 0 %左右