热压烧结短切εSiCf／LAS复合材料的介电性能

采用热压烧结法制备出致密的短切SiCf增强LAS玻璃陶瓷复合材料，讨论了热压保温时间与纤维长度对复合材料介电性能的影响。结果表明，测试频率在8～12GHz之间，复合材料的复介电常数实部ε′由基体的7．6上升到10～100，虚部，由基体的0．34上升到60～140，介电损耗tgδ由基体的0．04上升到1～40，并具有明显的频散效应。当保温时间由10min增加到20min时，复合材料ε′增大，ε″与tgδ减小。保温时间10min时，随着纤维长度由2mm增加到4mm，复合材料ε′减小，ε″先减小后增大，而tgδ增大；保温时间20min时，随着纤维长度由2mm增加到4mm，复合材料ε′先减小后增大，ε″与tgδ则先增大后减小。复合材料具有成为电损耗型宽带吸波材料的潜力。     

PVP修饰石墨烯对SBS改性沥青流变性能的影响

为研究经聚乙烯吡咯烷酮(PVP)处理后的石墨烯对SBS改性沥青流变性能的影响,通过高速剪切机在SBS改性沥青中掺入PVP修饰石墨烯,制备了石墨烯-SBS复合改性沥青,并采用动态剪切流变仪、温度扫描和线性振幅扫描试验,对复合改性沥青流变性能及抗疲劳性能变化规律进行研究,同时结合弯曲梁流变仪试验探索了复合改性沥青低温抗裂性...     

直链烷基苯磺酸镁的温和作用和应用性能（英）

对直链烷基苯磺酸镁盐（ＬＡＳ２ Ｍｇ） 与钠盐水溶液中诸多性质的对比做了大量研究。例如， 表面张力、临界胶束浓度、比电导、粘度、溶解性、生物降解性、毒性及耐硬水性等。同时， 对ＬＡＳ２ Ｍｇ 的其它性能如Ｚｅｉｎ 试验（ 一种皮肤刺激性试验） ， 润湿性及在盥洗用品和餐具洗涤剂中的应用性能也进行了测试。镁盐的一些特殊性质及其在洗涤剂和化妆品领域中新的应用的可能性得到了证实或确认。     

Structure and microwave dielectric properties of Li(Al1-xLix)SiO4-x ceramics

Li(Al_1-xLi_x)SiO_4-x (x = 0.005, 0.01, 0.015, and 0.02) ceramics were synthesized via a traditional solid phase reaction method with different sintering temperatures. To determine the positions occupied by Li⁺ in the lattice, the defect formation energies and total energies of various sites of LiAlSiO₄ (LAS) occupied by Li⁺ were examined, and the energy of LAS systems were calculated using density functional theory of first-principle with the CASTEP module. The results demonstrated that the Al-sites occupied by Li⁺ had the lowest formation energies and total energy, so Li ⁺ should substitute Al³⁺. The impacts of replacing Al³⁺ with Li⁺ on the bulk density, sintering properties, phase composition, microstructure, and microwave dielectric properties of Li(Al_1-xLi_x)SiO_4-x (0 = x ≤ 0.02) ceramics were thoroughly studied. With Li⁺-doping, the sintering temperature decreased from 1300 °C (x = 0) to 1175 °C (x = 0.02), while the Q × f and τ_f values of LAS ceramics significantly increased. The Li(Al_0.99Li_0.01)SiO_3.99 ceramic was fully sintered at 1250 °C for 10 h to obtain excellent microwave dielectric properties: ε_r = 3.49, Q × f = 51,358 GHz, and τ_f = ?51.48 × 10^?6 °C^?1.