基于用户体验视角下的老年人眼镜产品人性化设计研究

目的关注老龄化用户人群,从人性化设计与技术角度提升老年人生活过程中使用眼镜产品的用户体验,提出基于用户体验的老龄眼镜产品设计指导原则。方法研究老年人群用户体验视角下老年人的眼镜产品设计的关键点,研究老年人眼镜产品设计的功能定位。结论提出以改善用户体验人机交互为目标的针对高龄用户的人性化眼镜产品设计策略。     

Dynamic mechanical relaxation behavior of Zr35Hf17.5Ti5.5Al12.5Co7.5Ni12Cu10 high entropy bulk metallic glass

Non-equiatomic high entropy bulk metallic glasses were reported recently and show unique mechanical and physical properties.Dynamic mechanical relaxation behavior of Zr35Hf17.5Ti5.5Al12.5C07.5Ni12Cu10 high entropy bulk metallic glass was investigated by dynamic mechanical analysis(DMA)and the mechanical spectra could be well described by the quasi-point defects(QPD)theory.Compared to typical metallic glasses,the intensity of the β relaxation of Zr35Hf17.5Ti5.5Al12.5Co7.5Ni12Cu10 high entropy bulk metallic glass is lower due to the sluggish diffusion.At the same time,the correlation factor χ is higher than that of conventional metallic glasses and this is ascribed to the high configuration entropy.In paral-lel,physical aging below the glass transition temperature leads to a decrease of atomic mobility,caused by a decrease of the concentration of defects.     

Kinetics of light-assisted physical ageing in chalcogenide glasses

A fundamental understanding of glass relaxation under ambient temperatures, as well as under the external influences is vital to the glass and polymer science communities. Our results show that kinetics of light-assisted physical aging in Se-based glasses can be well fitted with stretch-exponential Kohlrausch type function, which exponent β and the effective time relaxation constant τ depend on the wavelength of incident photons. The obtained β values for Se-rich glasses group around 3/7 and 1/3 values, predicted by Phillips field-free and field-forced axiomatic diffusion-to-traps models.     

The elastic properties, elastic models and elastic perspectives of metallic glasses

Bulk metallic glass (BMG) provides plentiful precise knowledge of fundamental parameters of elastic moduli, which offer a benchmark reference point for understanding and applications of the glassy materials. This paper comprehensively reviews the current state of the art of the study of elastic properties, the establishments of correlations between elastic moduli and properties/features, and the elastic models and elastic perspectives of metallic glasses. The goal is to show the key roles of elastic moduli in study, formation, and understanding of metallic glasses, and to present a comprehensive elastic perspectives on the major fundamental issues from processing to structure to properties in the rapidly moving field.A plentiful of data and results involving in acoustic velocities, elastic constants and their response to aging, relaxation, applied press, pressure and temperature of the metallic glasses have been compiled. The thermodynamic and kinetic parameters, stability, mechanical and physical properties of various available metallic glasses especially BMGs have also been collected. A survey based on the plentiful experimental data reveals that the linear elastic constants have striking systematic correlations with the microstructural features, glass transition temperature, melting temperature, relaxation behavior, boson peak, strength, hardness, plastic yielding of the glass, and even rheological properties of the glass forming liquids. The elastic constants of BMGs also show a correlation with a weighted average of the elastic constants of the constituent elements. We show that the elastic moduli correlations can assist in selecting alloying components with suitable elastic moduli for controlling the elastic properties and glass-forming ability of the metallic glasses, and thus the results would enable the design, control and tuning of the formation and properties of metallic glasses.We demonstrate that the glass transition, the primary and secondary relaxations, plastic deformation and yield can be attributed to the free volume increase induced flow, and the flow can be modeled as the activated hopping between the inherent states in the potential energy landscape. We then propose an extended elastic model to understand flow in metallic glass and glass-forming supercooled liquid, and the model presents a simple and quantitative mathematic expression for flow activation energy of various glasses. The elastic perspectives, which consider all metallic glasses exhibit universal behavior based on a small number of readily measurable parameters of elastic moduli, are presented for understanding the nature and diverse properties of the metallic glasses.     

氢对Fe基和Fe-Ni基金属玻璃磁性和杨氏模量的影响

使用大角转动张力磁化法研究了金属玻璃 Fe_(80)Si_4B_4C_7,Fe_(39)Ni_(39)Si_8B_(12)Mn_2和(Fe_(30)Ni_(20))_(78)Si_(?)B_(14)三种样品渗氢及室温时效中磁化曲线和磁致伸缩系数λ_s 的变化,用动态测量方法研究了以上样品杨氏模量的变化。结果表明,含氢的金属玻璃饱和磁化强度 M:下降,而各向异性常数增大,相应饱和磁致伸缩系数λ(?)减小,同时杨氏模量降低。     

Metallic glasses from “alchemy” to pure science: Present and future of design,processing and applications of glassy metals

Metallic glasses, first discovered a half century ago, are currently among the most studied metallic materials. Available in sizes up to several centimeters, with many novel, applicable properties, metallic glasses have also been the focus of research advancing the understanding of liquids and of glasses in general.Metallic glasses (MGs), called also bulk metallic glasses (BMGs) (or glassy metals, amorphous metals, liquid metals) are considered to be the materials of the future. Due to their high strength, metallic glasses have a number of interesting applications, for example as coatings. Metallic glasses can also be corrosion resistant. Metallic glasses, and the crystalline materials derived from them, can have very good resistance to sliding and abrasive wear. Combined with their strength – and now, toughness – this makes them ideal candidates for bio-implants or military applications. Prestigious Journals such as “Nature Materials”, “Nature” frequently publish new findings on these unusual glass materials. Moreover Chinese and Asian scientists have also been showing an interest in the study of metallic glasses.This review paper is far from exhaustive, but tries to cover the areas of interest as it follows: a short history, the local structure of BMGs and the glass forming ability (GFA), BMGs’ properties, the manufacturing and some applications of BMGs and finally, about the future of BMGs as valuable materials.     

激活基因的玻璃

三十年前发现，生物玻璃能与骨形成骨键结合。这种特殊的材料已经有超过15年的临床应用，并在数以千计的成功病例。研究表明，骨的键合及骨再生和修复（骨形成作用）涉及玻璃表面的离子快速交换反应、生物活性表面反应层的成核和生长、由可溶硅和钙组成的临界浓度的离子溶解产物的释放。生物活性玻璃的分子生物学机理研究表明，它的生物活性响应看起来是由基因控制的。具有骨促进作用的A类生物活性玻璃通过直接对那些调节诱发细胞周期开始和进程的基因的直接控制，从而加强了其骨形成和促进作用。不能够形成新骨的细胞从细胞总体中被消除，这一特征是当成骨细胞在生物惰性材料或者B类生物活性材料培养时所没有的。骨前细胞细胞周期的基因调控生物学结果是成骨细胞的快速繁殖和分裂，这也导致了骨的迅速再生。对生物活性玻璃基因基础的理解，可以为设计新一代活化基因的玻璃材料，以及新一代活化基因的组织工程用生物降解支架提供重要的依据。如果我们能用玻璃激活基因，可以肯定，有一天我们就能用玻璃来控制基因。     

Cytoskeletal remodelling and slow dynamics in the living cell

The cytoskeleton (CSK) is a crowded network of structural proteins that stabilizes cell shape and drives cell motions. Recent studies on the dynamics of the CSK have established that a wide variety of cell types exhibit rheology in which responses are not tied to any particular relaxation times and are thus scale-free. Scale-free rheology is often found in a class of materials called soft glasses, but not all materials expressing scale-free rheology are glassy (see plastics, wood, concrete or some metals for example). As such, the extent to which dynamics of the CSK might be regarded as glassy remained an open question. Here we report both forced and spontaneous motions of microbeads tightly bound to the CSK of human muscle cells. Large oscillatory shear fluidized the CSK matrix, which was followed by slow scale-free recovery of rheological properties (aging). Spontaneous bead motions were subdiffusive at short times but superdiffusive at longer times; intermittent motions reflecting nanoscale CSK rearrangements depended on both the approach to kinetic arrest and energy release due to ATP hydrolysis. Aging, intermittency, and approach to kinetic arrest establish a striking analogy between the behaviour of the living CSK and that of inert non-equilibrium systems, including soft glasses, but with important differences that are highly ATP-dependent. These mesoscale dynamics link integrative CSK functions to underlying molecular events, and represent an important intersection of topical issues in condensed matter physics and systems biology.     

Raman microprobe investigation of oxygen and carbon dioxide dissolution from bubbles in silicate glasses containing antimony oxide

The effect of addition of antimony oxide and/or sodium nitrate to silicate glass compositions upon the changes in the relative concentrations of oxygen and carbon dioxide in their bubbles from heat treatment was investigated using the Raman microprobe technique. The addition of antimony oxide to these glasses increased the relative rates of oxygen dissolution from their bubbles with respect to glasses containing no refining agents. These increases were closely related to the absolute amounts of Sb³⁺ ions that were present in the glasses. The relative rates were faster for glasses containing antimony oxide than for glasses containing the same molar amounts of arsenic oxide. The higher Sb³⁺/Sb⁵⁺ ratios for glasses containing antimony oxide with respect to the As³⁺/As⁵⁺ ratios for glasses containing arsenic oxide caused the relative rates of oxygen dissolution to be dramatically greater for the former glasses. In contrast to an earlier investigation with silicate glasses containing arsenic oxide, the addition of sodium nitrate to glasses containing antimony oxide using a similar glass preparation did not significantly change their relative rates of oxygen dissolution.     

Anisotropic organic glasses

While the last decades have seen considerable efforts to control molecular packing in organic crystals, the idea of controlling packing in organic glasses is relatively unexplored. Glasses have many advantageous properties that crystals lack, such as macroscopic homogeneity and compositional flexibility, but packing in organic glasses is generally considered to be isotropic and highly disordered. Here we review and compare four areas of recent research activity showing control over anisotropic packing in organic glasses: (1) anisotropic glasses of low molecular weight organic semiconductors prepared by physical vapor deposition, (2) the use of mesogens to produce anisotropic glasses by cooling equilibrium liquid crystal phases, (3) the preparation of highly anisotropic glassy solids by vapor-depositing low molecular weight mesogens, and (4) anisotropic films of polymeric semiconductors prepared by spin-coating or solution casting. We delineate the connections between these areas with the hope of cross-fertilizing progress in the development of anisotropic glassy materials.     

Main α relaxation and slow β relaxation processes in a La30Ce30Al15Co25 metallic glass

Dynamic relaxation processes are fundamental to understand the mechanical and physical properties of metallic glasses. In the current work, mechanical relaxations in a La₃₀Ce₃₀Al₁₅Co₂₅ bulk metallic glass were probed by dynamic mechanical analysis. In contrast to many metallic glasses, La₃₀Ce₃₀Al₁₅Co₂₅ metallic glass shows a pronounced slow β relaxation peak. Physical aging below the glass transition temperature T_g leads to an increase of the apparent activation energy and a decrease of the slow β relaxation magnitude. The correlation between the slow β relaxation and the main α relaxation is discussed.     

Complex Faraday rotation in microstructured magneto-optical fiber waveguides

Magneto-optical glasses are of considerable current interest, primarily for applications in fiber circuitry, optical isolation, all-optical diodes, optical switching and modulation. While the benchmark materials are still crystalline, glasses offer a variety of unique advantages, such as very high rare-earth and heavy-metal solubility and, in principle, the possibility of being produced in fiber form. In comparison to conventional fiber-drawing processes, pressure-assisted melt-filling of microcapillaries or photonic crystal fibers with magneto-optical glasses offers an alternative route to creating complex waveguide architectures from unusual combinations of glasses. For instance, strongly diamagnetic tellurite or chalcogenide glasses with high refractive index can be combined with silica in an all-solid, microstructured waveguide. This promises the implementation of as-yet-unsuitable but strongly active glass candidates as fiber waveguides, for example in photonic crystal fibers.     

The effect of environment pressure on high temperature stability of silicon oxycarbide glasses derived from polysiloxane

Silicon oxycarbide glasses (SiOC) have been produced by siloxane resin under flowing argon atmosphere at 1000 °C. Those glasses were further annealed at 1200, 1300, 1400, and 1500 °C under the pressure of 0.01 KPa and 101 KPa, respectively, to investigate the effect of environment pressure on their high temperature stability. The two series of glasses were characterized by X-ray diffraction, ²⁹SiMASNMR, and chemical element analysis. The environment pressure plays a crucial role on high temperature stability of SiOC glasses by promoting or hindering bonds redistribution and carbothermal reductions. It can be found that SiOC glasses exhibit enhanced thermal stability in high pressure environment.     

Optical absorption of nickel (II) in Na2O-NaCl-B2O3 and Na2O-NaBr-B2O3 glasses

The optical absorption spectra of nickel(II) have been studied in Na₂O-NaX-B₂O₃ glasses X = Cl or Br); the absorption bands have been interpreted in terms of Ligand Field Theory. In halide-free B₂O₃-rich glasses nickel(II) is octahedral, and halide substitution is accompanied by the formation of a tetrahedral nickel(II)-oxide-halide complex. In alkali-rich glasses nickel(II) is square planar and/or tetrahedral and no halide substitution can be observed. It is suggested that the halide ions are unable to substitute for oxygen in the predominantly covalent nickel(II)-oxygen bonds of the complex formed in basic glasses.     

Electrical properties of glasses in the Na2O–MoO3–P2O5 system

A range of coloured electronic or mixed ionic–electronic glasses has been evidenced in the Na₂O–MoO₃–P₂O₅ system. The properties of these glasses have been studied along different composition lines corresponding either to a fixed Na₂O content or a constant Mo/P ratio. An EPR spectroscopy investigation of these glasses has allowed to determine the Mo⁵⁺ ion percentages in these materials. The electrical properties of these glasses have been studied by impedance spectroscopy, and the electronic and ionic contributions have been evaluated. The properties of these sodium glasses have been compared with those of lithium glasses with the same compositions.     

Infrared glasses

Driven by applications in hot fields such as optical communications, lasers, sensors, etc. infrared glasses have to be considered as key components in the development of devices for telecom signal amplification, fibre-laser emission as well as for passive functions related to IR remote spectroscopy or thermal imaging. Stable vitreous materials with low-phonon energies are found in the family of fluorides and chalcogenides glasses; they offer the advantage of excellent transparency in the mid-IR and weak nonradiative relaxation when doped with rare earth elements. Despite the number of candidates only a very limited number of glass compositions can be shaped into good optical waveguides such as channel or fibre. When possible, this led to remarkable amplification in the 1.3 μm region and lasing emission in the blue or mid-IR. Non-linear optical properties of chalcogen-based glasses are also of special interest for fast all optical switching and photo-induced effects.     

Oxide glass filaments and their superconducting phase by annealing

Bi₄Ca₃Sr₃Cu _x O _y (4334) oxide glasses with different concentrations of the transition metal copper have been prepared by rapid quenching technique from respective melts. These glasses have been characterized from electrical, magnetic, dielectric and other properties. The semiconducting glasses are not superconducting even down to 4·2 K. However, by properly annealing the glasses in air or in oxygen atmosphere they can be converted into the corresponding superconducting phases with superconducting transition temperatures between 70 and 110 K depending on the Cu ion concentrations. The dc conductivity of the glasses could be explained with small polaron adiabatic hopping mechanism. Analysis shows that the correlated barrier hopping (CBH) mechanism is the most appropriate model for explaining the a.c. conductivities of these glasses. Addition of a small amount (about 2 wt%) of B₂O₃ makes it possible to draw glass filaments which could also be converted into the superconducting phase withT _c values lower than those obtained from the respective pure glasses.     

Properties of the glasses prepared by rapid quenching in the V2O5-MO(M=Mg,Ca and Ba) system

Rapidly quenched glasses in the V₂O₅-MO (M=Mg, Ca and Ba) systems have been prepared by a twin-roller technique. Glasses up to 40 mol% MgO and 50 mol% CaO or BaO were obtained. No metastable phase was observed in the crystallization processes. From the infrared spectral data for the glasses, the structural change of the glasses are discussed. The electrical conductivity of the glasses decreased with increasing MO content, and the electrical behaviour of the glasses has been related to the structural change of the glasses.     

A study of neutron and gamma radiation effects on transmission of various types of glasses, optical coatings, cemented optics and fiber

A study of radiation effects on various types of glasses, dielectric optical coatings, cemented optics and fiber was undertaken with a view to select them for extreme radiation environments. Samples were exposed to different radiation doses in the Pakistan Research Reactor-I (PARR-I) for neutron and Cobalt 60 source for gamma irradiation. Transmissions were measured before and after irradiation. The dielectric coatings were subjected to additional tests (adhesion, abrasion and humidity, etc.) as per MIL-M-13508C and MIL-C-675C. All 15 glasses studied showed varying amounts of transmission loss as expected, with negligible degradation for three types. Recovery of transmissions with time/ageing was also studied, with more or less complete recovery with temperature annealing. A faster bleaching of darkened/brown glasses was achieved by using UV lamps or UV laser. The dielectric coatings (HR, AR) and one of the two commercial optical cements showed excellent resistance to neutrons and gamma radiations, and could be good candidates for the fabrication and utilization of optical components in extreme radiation environments. The data allowed several Chinese glasses to be studied for the first time.     

Structure,thermal properties,dissolution behaviour and biomedical applications of phosphate glasses and fibres: a review

For the last few decades, there has been a growing interest in using glasses for biomedical applications. Bioactive glasses are a group of surface reactive glasses which can initiate a range of biological responses by releasing ions into the local environment. Silicate, borate and phosphate glasses are known to show good bioactive characteristics and could be potentially used as favourable templates for bone-tissue formation. Phosphate glasses are unique group of materials that offer great potential for hard and soft tissue engineering over other types of bioactive glasses due to their fully resorbable characteristics, with some formulations possessing chemical composition similar to the mineral phase of natural bone. Moreover, these phosphate glasses can be prepared as fibres which could be used for soft tissue engineering and as fibrous reinforcement for resorbable polymers such as poly-(lactic acid) for fracture fixation applications. This review details some of the properties of phosphate glasses, such as thermal, viscosity/temperature, dissolution and biocompatibility of and how different factors can effectively alter these properties. The effect of the addition of different modifier oxides on the structure in terms of chain length is included. This review also reports on the manufacturing process, mechanical properties and biomedical application of phosphate glass fibres. A brief comparison between three different types of bioactive glasses has also been presented in this review. The main aim of this review is to present the factors affecting the properties of phosphate glasses and glass fibres and how these may be exploited in the design of a biomaterial.