可腐蚀的

The results show that a MgSnO3·H2O conversion film is formed by treatment in the stannate solution at 90℃, and the immersion test and potentiodynamic polarization show that the corrosion resistance of the AZ91D alloy is improved to some extent.

结果表明：锡酸盐转化处理后合金表面形成了以MgSnO3·H2O为主要成分的转化膜，可对合金起到一定的防护作用；转化膜由细小的球形颗粒密积而成，颗粒之间存在间隙，它可以为化学镀镍的前处理过程提供良好的吸附条件；转化膜上的化学镀镍层组织致密、无缺陷， MgSnO3·H2O转化膜在镀镍层与基体之间起到过渡作用，镀层的磷含量达到9%，与基体结合良好；在3.5% NaCl (pH=7)溶液中的动电位极化测试表明，镀镍以后的合金在阳极极化过程中发生了明显的钝化，耐腐蚀性能进一步提高，对基体起到了较好的防护作用。

Below 300 300 to 1200 Ordinary Portland or Portland blastfurnace Ordinary Portland or Portland blastfurnace Sulphate resisting Supersulphated Sulphate resisting or Supersulphated High alumina Sulphate resisting or Supersulphated High alumina Sulphate resisting or Supersulphated with adequate protective coating High alumina Minimum cement content (kg m-3) Type of cement Maximum size of aggregate 37.5 240 290 240 270 290 290 330 330 330 330 19.0 280 330 280 310 330 330 370 340 370 370 9.5 330 380 330 360 380 380 420 410 420 420 0.55 0.50 0.55 0.50 0.50 0.45 0.45 0.40 0.45 0.35 Maximum water-cement ratio 0.5 to 1.0 1.0 to 2.0 1200 to 2500 2500 to 5000 Over 2.0 Over 5000 Wear

这些气 穴通常由具有格外高能量的水蒸气所填充，与混凝土表面的反复接触导致形成凹陷和孔洞，即气蚀。既然高质混凝土也不能抵抗这种劣化，因此最好的补救是通过制造平滑水流来消除气蚀。在所有必须的地方，关键的面上衬以高抗气蚀性的材料。通常，混凝土抗腐蚀和磨损的能力随强度增加而提高。采用硬韧的集料可改善混凝土的抗磨损性。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失