The navy and much of the maritime industry use nickel - aluminum - bronze ( nab ) as the primary material for propeller construction . this is done for many reasons , including its high stiffness , and low corrosion potential . it is , essentially , the standard in the industry 过去,许多海军和海洋工业都使用镍铝合金铜( nab )作为生产螺旋桨的主要原材料,因为它具有较高的硬度和较低的腐蚀性能,并且一直以来都是工业生产中的标准材料。
Chenhao ( shanghai ) machine inc , the branch company of chentai was found in oct of 2003 in order to provide a better service for our customers . the main management digitalinclined disk screw washer assembly machine 、 feeding machine 、 the replenish pail and the related fitting product evenly , its main raw material all imports 随著企业的发展，于2003年10月在上海设立上海振好机械有限公司，以便更好的为用户提供服务，主要经营数控斜盘螺丝华司组合机、振动送料机、筛选机、直线送料机、补料桶及相关配件产品，其主要原材料全部进口。
Mr paul cheung kwok - wing , chairman , kingboard chemical holdings ltd , said : " caustic soda is a common chemical base for many industries and china as the world s factory has strong demand for this chemical . since we can utilize local natural resources salt as raw material , we enjoy a low cost benefit in producing caustic soda in hengyang . 建滔化工集团主席张国荣先生称：烧硷是一种广泛应用于生产工业的化工原料，中国作为世界工厂，对烧硷有大的需求，加上能采用当地丰富天然资源盐卤作为生产烧硷的主要原材料，集团在衡阳生产烧硷更具优势。
In the paper the effects of the made parameters , the main materials and environmental conditions on plastic shrinkage cracking were investigated . it can be concluded as following : 1 ) there was a critical w / c ratio of maximum plastic shrinkage cracking between lower and higher w / c ratio of concrete mixtures made with the same cement content per cubic meter , concretes with lower or higher w / c ratio being less prone to plastic shrinkage cracking and the w / c critical ratio critical of maximum plastic shrinkage cracking being about 0 . 5 本文研究了配制参数、主要原材料以及环境条件对新拌混凝土塑性收缩裂缝的影响，结果表明： 1 ）单方混凝土水泥用量一定时，较低水灰比和较高水灰比对应的混凝土拌合物不易开裂，而中间某一临界水灰比对应的混凝土拌合物开裂较严重，这一临界水灰比为0 . 5 ；单方混凝土水用量或水泥浆量一定时，混凝土拌合物的塑性开裂趋势与上述情况相似，但临界水灰比分别为0 . 45 - 0 . 4和0 . 4 。
The implementation regulations provide that the reduction in taxable income is 10 % , given that the main materials for the products should come from the prescribed resources under the " catalog for the preferential tax treatment on the integrated utilization of resources " and that the products should meet the industry standards and do not fall under the restricted and prohibited categories 实施条例据此明确，企业以《资源综合利用企业所得税优惠目录》规定的资源作为主要原材料并符合规定比例，生产国家非限制和禁止并符合国家和行业相关标准的产品取得的收入，减按90计入收入总额。
Leather is main material for making shoes , in shoemaking the main working procedures are nesting and cutting all kinds of shoe parts on leather with high quality , but it is inevitable that there are all kinds of defects on leather , such as scratch , mites ( insect bites ) and scars , so it is necessary to detect the positions and size of defects before nesting and cutting shoe parts in order to utilize materials effectively 皮革是制鞋的主要原材料，制鞋的主要工序是在优质皮革上排放和切割各种鞋样部件，但是皮革表面不可避免的存在各种缺陷，如虫咬、疤痕和划伤等，为了有效利用原料，在排样和切割之前要首先定位皮革表面的缺陷区域。
