玻璃盘基对高密度硬盘介质静态磁性参数测量的影响和消除方法

高密度硬盘介质静态磁性参数的精确测量对研制高密度硬盘至关重要.本文从测量系统和材料两方面对玻璃基噪声的影响机理做了较详尽的分析;并介绍了消除玻璃基噪声影响的四种方法,这四种方法在测量同一硬盘介质静态磁性参数时相对偏差小于5%,因此这四种方法都是切实可行的.     

镁基大块非晶合金的制备与性能研究

采用铜模浇铸的方法成功制备了最大直径为12mm的Mg65Cu20Ag5Gd10非晶合金,并对其结构、热稳定性能、非晶形成能力、压缩性能及断口形貌进行了分析.结果表明,Mg65Cu20Ag5Gd10具有较强的玻璃形成能力和良好的热稳定性能;合金的断裂强度达895MPa,弹性应变为2.35%.     

Enhancement of optical emission generated from femtosecond double-pulse laser-induced glass plasma at different sample temperatures in air

In double-pulse laser-induced breakdown spectroscopy(DP-LIBS), the collinear femtosecond double-pulse laser configuration is experimentally investigated with different initial sample temperatures using a Ti:sapphire laser. The glass sample is ablated to produce the plasma spectroscopy. During the experiment, the detected spectral lines include two Na(I) lines(589.0 nm and 589.6 nm) and one Ca(I) line at the wavelength of 585.7 nm. The emission lines are measured at room temperature(22 ℃) and three higher initial sample temperatures(T_s?=?100 ℃, 200 ℃, and 250 ℃). The inter-pulse delay time ranges from-250 ps to 250 ps.The inter-pulse delay time and the sample temperature strongly influence the spectral intensity,and the spectral intensity can be significantly enhanced by increasing the sample temperature and selecting the optimized inter-pulse time. For the same inter-pulse time of 0 ps(single-pulse LIBS), the enhancement ratio is approximately 2.5 at T_s?=?200 ℃ compared with that obtained at T_s?=?22 ℃. For the same inter-pulse time of 150 ps, the enhancement ratio can be up to 4 at T_s?=?200 ℃ compared with that obtained at T_s?=?22 ℃. The combined enhancement effects of the different initial sample temperatures and the double-pulse configuration in femtosecond LIBS are much stronger than that of the different initial sample temperatures or the double-pulse configuration only.     

中温SOFC密封玻璃热稳定性研究

研究了一种热稳定性好的中温固体氧化物燃料电池密封玻璃. 研究表明, 此密封玻璃的热膨胀系数(室温～631℃)为9.8×10^-6/K, 与8YSZ电解质的热膨胀系数10.0×10^-6/K(室温～631℃)接近, 并且在700℃热处理300h后, 该密封玻璃的热膨胀系数几乎没有变化. 粘度实验表明, 玻璃在700℃下具有足够的刚性, 适合于运行温度在700℃左右SOFC的密封. 化学相容性的研究显示, 在700℃下与8YSZ反应300h后没有发现显著的界面反应.     

用Interphako干涉显微镜测量离子交换玻璃薄片中的梯度折射率分布

本文用 Interphako 干涉显微镜测量了经 NaNO_3盐浴处理的玻璃薄片中的梯度折射率分布。将剪切微差干涉测得的结果与剪切干涉的结果进行了比较,并讨论两种测量方法的特点和误差。     

组成无公害低熔玻璃的发展现状

低熔玻璃广泛用作封接玻璃和电子浆料中的粘接相.现有低熔玻璃绝大部分为高铅含量玻璃.提出组成中不合PBb、Hg、Cd、As、Tl、Cr和放射性元素的玻璃称为组成无公害玻璃,综述了低熔玻璃的发展现状,指出电子产品目前所用含铅玻璃的取代物可能是磷酸盐、矾酸盐、铋酸盐玻璃.建立磷酸盐、矾酸盐、铋酸盐玻璃相关基础理论,发展玻璃形成新理论以及新的材料制备技术是组成无公害低熔玻璃研究与开发的重点.     

镀银玻璃微珠/炭纤维填充导电硅橡胶的电磁屏蔽性能

分别研究了用镀银玻璃微珠,炭纤维和镀银玻璃微珠/炭纤维复合填料填充的硅橡胶的电磁屏蔽效能。结果表明,在2.6 GHz~3.95 GHz频段内,镀银玻璃微珠填充量越大,导电硅橡胶的电磁屏蔽效能越高,镀银玻璃微珠填充量为180份时,样品的屏蔽效能的峰值为-115.2 dB。添加少量炭纤维能够提高镀银玻璃微珠/炭纤维复合填料填充橡胶的电磁屏蔽性能,当炭纤维添加量增加到20份时,镀银玻璃微珠/炭纤维复合填料填充硅橡胶(镀银玻璃微珠填充量120份)的电磁屏蔽效能峰值达到-82.0 dB,高于填充量为150份的单纯镀银玻璃微珠填料样品的电磁屏蔽效能,并且能够提高导电硅橡胶的力学性能并降低成本。     

纤维长度,取向对LAS基体力学性能的影响

本文研究了短切碳纤维增强LAS玻璃-陶瓷（以下简称C_sf／LAS）复合材料的制备工艺以及纤维长度、取向对其力学性能的影响．获得了短切碳纤维均匀分散并取向排列的复合材料,用扫描电子显微镜和光学显微镜观察了复合材料的断口形貌和显微结构．研究发现短切碳纤维增强LAS玻璃-陶瓷的主要强韧化机理是载荷传递和纤维拔出．     

玻璃微珠的应用研究进展

介绍了玻璃微珠的类型及其特性,综述了近年来玻璃微珠的应用研究进展,包括在建材、塑料、橡胶、涂料、医药等领域的应用情况。改性后的玻璃微珠可应用于电磁屏蔽和吸波材料的制备,拓宽了其应用范围,并分析了其应用前景。     

Fatigue analysis of unidirectional GFRP composites under combined bending and torsional loads

Fatigue behavior of unidirectional glass fiber reinforced polyester (GFRP) composites at room temperature under in-phase combined torsion/bending loading was investigated. All fatigue tests were carried out on constant-deflection fatigue machine with frequency of 25 Hz. A 30% reduction from the initial applied moments was taken as a failure criterion in the combined torsion/bending fatigue tests of the composite materials. A series of pure torsional fatigue tests were conducted to construct the failure contour of GFRP composites using different failure theories. The obtained S–N curves from combined torsion/bending tests were compared with both, pure torsion fatigue test results and published results of pure bending fatigue tests of GFRP rods. Pictures by scanning electron microscope were used to closely examine the failure mode of the tested specimens under combined torsion/bending loading.

The results showed that, the unidirectional glass fiber reinforced polyester composites have poor torsional fatigue strength compared with the published results of pure bending fatigue strength. Endurance limit value (calculated from S–N equation at N = 10⁷ cycles) of GFRP specimens tested under combined torsion/bending loading equals 8.5 times the endurance limit of pure torsion fatigue. On the other hand the endurance limit of combined torsion/bending fatigue strength approximately half the fatigue limit of pure bending fatigue strength. The predicted values of combined torsion/bending fatigue strength at different number of cycles, using the published failure theory are in good agreement with the experimental data. For the investigated range of fiber volume fractions (V_f) it was found that higher stress levels are needed to produce fatigue failure after the same number of cycles as V_f increases.