材差

西康铁路设计概算中材差计算技巧

Calculating technique on difference of cost of materials in budgetary estimate of design for XI'AN-ANKANG Railway

镁砂铝矾土、硅粉、硅粉镁砂铝矾土体系焊料可塑性差、分散性差、易固化且与Si3N4陶瓷母材粘附性差；

The slurry properties of the Magnesia & Bauxite adhesive is poor in plasticity and conglutination with Si_3N_4 ceramics , which also solidify easily .

最后针对国内集成材产品质量差的状况提出了“集成材产品质量保证系统”这一本质上的解决途径。

Finally the author introduces the way of Quality Control System in order to resolve the problem of bad quality of domestic Glulam products in essence .

焊缝与母材间的硬度差及焊缝本身的高硬度、低塑性等原因导致了焊缝一侧容易产生应力集中，先于焊缝断裂。

The gradient distribution of the hardness , itself high hardness and low plasticity led the side of seam to stress concentration and fracture prior to welding seam .

铜材的防污性能最好，低表面能材料如聚四氟乙烯、硅橡胶等防污性能优良，聚氯乙烯材料防污性能较差，而钛材防污性能最差。

Among these materials , Cu and Cu-alloy win the best antifouling properties , the lower surface energy materials , such as PTFE and silicone rubber , have shown good antifouling properties , PVC and Ti-alloy have shown poor antifouling properties .