表面硬化的

The developing principle of MB gypsum fine foamer which takes compound honey-locust abietic acid anionic surfactant as principal composition,is analyzed in theory.

从理论上分析了以复合型皂角松香酸类阴离子表面活性剂为主要成分的MB石膏微发泡剂的研制原理，详细研究了MB微发泡剂在石膏料浆中的起泡条件、起泡性能及其对硬化后的建筑石膏物理力学性能的影响，MB微发泡剂与现有发泡剂的性能比较，MB微发泡剂在纸面石膏板中的应

This welding wire not only has the inherent properties of metal powder-cored wire, such as with better welding quality, without slag, highly efficiency and conveniently adjusting the alloying elements etc., but also has the advantage of low hardness in as-welded (less than HRC45), good machinability, high hardness in as-aged (more than HRC55) and better wear resistance with customary working procedure on making or repairing equipments such as rollers when reasonable designing the alloys content. The author adequately makes use of the high-tempering in the required stress relieving working procedure. During this working procedure, which causes the hardness of overlaying metal increased by the reason of austenite changes into tempered martensite and more chiefly what is the precipitation of a lot of carbide by secondary hardening simultaneously. This wire can solve the hard rolled problems of some solid wires with higher alloys while it can get over the conflict of existing overlaying materials what are always possesed high hardness with poor machinability or low hardness, good machinability with poor wear resistance. Further, it also can overcome the intenerating phenomena between welding beads and make the external hardness of overlaying metal uniform. Be sure it could be found important meaning in the overlaying of wear-resistant equipments, such as the precise roller.

该焊丝除了具有金属粉型药芯焊丝焊接质量好、无渣、高效率和合金成分可方便调节等固有的优点外，合理的设计粉芯中的合金成分，按通常工序制造与修复轧辊等设备，充分利用必需的消除应力工序的高温回火，堆焊层金属在奥氏体转变为回火马氏体的同时更主要是通过二次硬化析出了大量碳化物导致硬度增加，使得该焊丝还具有焊态硬度低(小于HRC45)、机加工性能好和时效态硬度高(大于HRC55)、耐磨性能好等优点，解决了某些高合金实芯焊丝轧制困难的问题，同时克服了现行堆焊材料硬度高、加工性能差或者硬度低、加工性能好、耐磨性差的矛盾，并能克服焊道之间的软化现象，使堆焊表面硬度较为均匀，对耐磨件，譬如精轧辊的堆焊具有重要意义。

We find that the proportion of the contribution of the three factors on the fatigue strength improvement of the peened joints depends on the base metal static strength.

结果表明：超声冲击处理提高焊接接头疲劳强度的硬化，改善焊趾几何外形和在焊趾区形成表面压应力三者贡献的大小，与被处理焊接接头的母材静强度有一定的相关性。

It was believed that either alumina reacted with impurities in the iron powder or the surface diffusion caved the alumina particles to stick to the iron powder surfaces. Another approach was to use the air classifier mill to break up the sintered iron cakes into powders. The morphology of such particles was classified into 4 types in this study: irregular, equalaxed, near spherical, and flaky. The morphological differences were affected by the extent of sintering. The higher the extent of sintering, the stronger the inter-particle bonding.

此外，本实验利用空气分级气流粉碎机将还原后的烧结体进行粉碎，实验结果显示粉碎后的粉末形貌可以分为四种，不规则形、等轴形、近球形和片形，形貌上的差异是由於还原时铁粉烧结程度的不同，烧结程度越高，粉末间键结强度越强，因此粉碎过程中会产生高程度的塑性变形，以至於粉末形貌越来越接近球形，最后因粉末表面大量加工硬化产生破裂，形成片状碎屑。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。