Nd：碲酸盐玻璃的光谱和激光性质

对比了各种激光玻璃的光谱性质，指出碲酸盐玻璃是一咱理想的激光介质，并资产在室温下实现了钛宝石激光器泵浦了Ｎｄ：碲酸盐块体玻璃的激光发射，激光阈值４．２０ｍＪ，斜率效率１４．７％。     

Cure reaction for modified diallylbisphenol A/diaminodiphenylsulfone/bismaleimide

The glass‐transition temperature as a function of curing conversion for a modified diallylbisphenol A/diaminodiphenylsulfone/bismaleimide (BMI) resin was investigated at different temperature regimes and modeled using a modified Di Benedetto equation. Although the relationship between the glass‐transition temperature and conversion of the BMI system conforms to the Di Benedetto equation for α < 0.6 and at lower cure temperatures, at higher cure temperatures the results deviated significantly from the equation; thus, it was an inadequate model for the system. Fourier transform IR analysis showed that the major crosslinking reactions did not occur during cure for the modified BMI at and below 150°C. However, as the cure temperature was increased, the crosslinking reactions responsible for 3‐dimensional network structures became more dominant. At 190°C the C? N? C_stretch vibration of the uncured maleimide ring converted into succinimide rings in the curing process. Simultaneously, a decrease was observed for the absorbance bands of ? C? H_bending (maleimide). The higher cure temperatures induced a significantly faster initial crosslinking rate and also resulted in a shorter period of time after which further crosslinking was retarded, because the increase in the crosslinks also physically slowed further crosslinking activity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 227–235, 2002     

Experimental evaluation of the strength distribution of E-glass fibres at high strain rates

A bimodal Weibull distribution function was applied to analyse the strength distribution of glass fibre bundles under tensile impact. The simulation was performed using a one-dimensional damage constitutive model. The results show that there were two concurrent flaw populations in the fracture process. The regression analysis using the bimodal Weibull distribution function was in good agreement with experiment.     

Dynamics of hydrated iron(II) cations in nafion polymer membranes

Mössbauer studies of Fe²⁺ in water-soaked nafion polymer membranes in the temperature range between 90 K and 250 K have been performed. Above a critical temperature (～ 180 K) the spectra exhibit both elastic narrow absorption lines and quasielastic broad lines. These spectra are typical of bounded diffusion phenomena observed by Mössbauer spectroscopy in macromolecular systems like haemoglobin, myoglobin and ferritin. Similar spectral shapes have been observed by quasielastic neutron scattering from water in nafion membranes. Within 50 K above the critical temperature the total Mössbauer absorption area decreases by an order of magnitude whereas the narrow absorption line decreases by two orders of magnitude. The results are interpreted in terms of bounded diffusive motion of the iron. Using a model based on overdamped harmonically bound Brownian motion, the essential parameters of the iron motion can be derived as a function of temperature. The iron motion most probably reflects the motion of a large Fe²⁺ complex, e.g. Fe(H₂O)²⁺₆, which is attached to the polymer side chains via the sulphonic group.     

拉伸速率对PP/GB复合材料力学性能的影响

应用Instron材料试验机考察了室温下拉伸速率对玻璃微珠填充聚丙烯复合材料的弹性模量和屈服强度的影响，结果表明，随着微珠含量的增加，试样的弹性模量（Ec）增大，且与拉伸应变速率呈近乎幂律函数关系，而屈服强度（бyc）则随着微珠体积分数（Φf）的增加呈线性函数形式下降，并随着拉伸应变速率的增加呈幂律函数形式提高，此外，讨论了Ec、Φf与бyc三者之间的关系。     

Electrical Resistance Measurement of Glass Transition and Crystallization Characteristics of Zr—Al—Cu—Ni Metallic Glasses

In this paper,glass transition and thermal stability of the Zr-Al-Cu-Ni metallic glasses were investigated by using electrical resistance measurement(ERM),DSC and X-ray diffraction techniques.The experimental results show that the ERM is capable of detecting the glass transition of the amorphous alloys and can help to distinguish the crystallization products of the Zr-Al-Cu-Ni metallic glasses owing to the difference of the electrical resistivity between the precipitation phases.     

Sol-gel processing: A versatile concept for special glasses and ceramics

The various parameters related to sol-gel processing are discussed with special reference to those which usually attract less attention but depending on the final product in mind, can play important roles. The versatility of the sol-gel technique in materials preparation is demonstrated by discussing the various products developed at the author’s laboratory by using this processing method.     

改性玻纤增强尼龙610,1010塑料

研究了采用(准)中粘度级尼龙做基体树脂,加入成核剂改善尼龙的结晶过程,提高结晶速率和初始熔融温度;添加光、热氧稳定剂,防止尼龙在成型加工和使用过程中产生降解与老化,提高塑料制品的质量和减少性能的分散性;采用合理的工艺条件,确保添加剂的均匀分散与减少玻纤的磨损,得到适于军工、航空和机电等领域需要的高性能的受力结构工程塑料。