偏心轴设计及其有限元分析

偏心轴是完成曲柄摇杆机构的另一种形式,在我们的结构设计中经常在颚式破碎和其他一些进行复摆运动的机构中用到。应用十分广泛,但是由于其形状结构特殊,使得轴局部受力不均匀,这让生产制造很是受限。所以凭借有限元分析技术对偏心轴的受力进行系统分析,找出其最容易受损的部位和受力面,从而可以对轴进行校核改进。     

单轴桨叶式饲料调质器国内外概况

文章论述了国内外单轴桨叶式饲料调质器产品的技术发展概况。国外著名饲料机械公司生产的单轴桨叶式调质器质量处于国际领先水平。新型单轴桨叶调质器的主轴采用变频调速技术,各检修门配有安全连锁装置。调质器桨叶与机壳间隙可调节至4～5 mm。调质器机筒采用大直径,桨叶采用较大宽度。国内大型饲料机械企业的单轴桨叶式调质器的质量优良,部分小型饲料机械企业生产的同类调质器的制造质量不高。需要对该类产品制定相关国家或行业标准。     

新疆山羊皮肤毛囊结构及周期性发育规律的研究

[目的]探索新疆山羊毛绒性状和皮肤毛囊的发育规律,[方法]分别在3月、6月、9月、12月取毛样和体侧部皮肤,检测毛样绒细度、长度、净绒率。皮肤切片后采用sacpic法染色,观察毛囊的生长发育规律。[结果]新疆山羊绒平均细度约为15.16μm,长度为46.6mm,净绒率为28.8%;毛囊活性、深度、密度均以9月份为最高,3月份最低,说明9月为新疆山羊毛囊的兴盛期,3月份为静止期。[结论]从绒细度、长度来看,新疆山羊属于绒山羊中的优秀品种,而且初、次级毛囊密度高,在后期选育对于提高生产性能具有很大的潜力。     

收割机驱动轴断裂研究

对收割机筛箱驱动轴早期疲劳断裂进行了分析研究,得出该驱动轴因为本身材料以及加工工艺不当等原因,造成局部应力集中超过驱动轴承载能力引起早期断裂。     

轮式拖拉机输入和输出轴绿色材料的研究

运用模糊数学理论,以农用机械轮式拖拉机前置动力输出装置中的输入轴和输出轴为研究对象,选取农业机械制造中常用的金属材料,并综合考虑金属材料的各种性能因素,进行评价分析研究,得出一种制造输入轴和输出轴的最优材料为绿色制造材料,完成绿色制造选取绿色材料的一个重要环节。     

Environmental and genetic variation of the effective radiative properties of the coat of Holstein cows under tropical conditions

Morphological characteristics, coat effective radiative properties, and the percentage of white colour were measured in the coats of 973 Holstein cows, and estimates of the genetic parameters were obtained for these traits, except morphological characteristics. The results showed that white coats are more dense with long, thin hairs, while the black coats are less dense with short, thick hairs. Effective transmissivity is greater in the less-dense coats with short, thin hairs, independently of coat colour. Effective reflectivity depends more on the variation in the radiative properties of the coat and skin surface rather than on the morphological characteristics of the coat. Effective absorptivity is greater in black and dense coats with long, thick hairs, than in the white and less-dense coat with short, thin hairs. All heritability estimates were of low magnitude, except for the percentage of white coat colour.     

轴类零件中的键槽加工

键槽加工是轴类零件加工中经常遇到的问题。对键槽的技术要求、装夹方法特别是加工方法进行阐述,重点对键槽铣削加工经历的3个阶段包括普通铣床加工、键槽铣床加工、数控铣床和加工中心加工过程中加工刀具的选用、走刀路线的确定、加工质量的对比以及加工特点进行了分析比较。     

毛发杂波型鳞片磨损机制的研究

在实验的基础上,提出了“毛发鳞片磨损学说”：即毛发鳞片形态并非都是生俱来的,毛发在外界环境的作用下,某些类型的鳞片,如规则扁平鳞片的形态会发生磨损而形成杂波型,杂波型鳞片的复杂程度与摩擦方式和强度有关;理化因素了可以促进或减轻磨损,鳞片磨损是毛发的一种高效的保护性适应,”毛发鳞片磨损学说“对于毛加工工艺的改进,毛皮产品的养护,美发与护发及动物种属识别技术具有重要意义。     

刚粘塑性圆轴扭转和拉伸的组合变形

分析了不可压缩刚粘塑性圆扭转和拉伸的组合变形，作为特例，了圆轴只承受拉伸和只承受扭转时的情况。     

The effects of thyroid hormones on the skin of beagle dogs

The effects of hypothyroidism on canine skin were determined by comparing morphologic, morphometric, and hair cycle differences in skin biopsy samples from 3 groups of age- and gender-matched Beagle dogs: (1) euthyroid dogs; (2) dogs made hypothyroid by administration of 131I; and (3) dogs made hypothyroid and maintained in a euthyroid state by treatment with synthetic thyroxine. After 10 months of observation, there was slower regrowth of hair 2 months after clipping in the untreated-hypothyroid dogs. Untreated-hypothyroid dogs had a greater number of follicles in telogen and fewer hair shafts (ie, a greater number of hairless telogen follicles) than did the control group. The control dogs had a greater number of telogen follicles but the same number of hair shafts as the treated-hypothyroid group. Treated-hypothyroid dogs had the greatest number of follicles in the growing stage of the hair cycle (anagen). This study suggests that, at least in Beagles, induced hypothyroidism does not affect the pelage as dramatically as has been described in naturally occurring disease. This is because normal Beagles retain hair shafts in follicles for long periods, and the alopecia of hypothyroidism appears to evolve slowly because of the prolongation of this haired telogen stage. The evaluation of thyroxine-treated hypothyroid dogs demonstrates that thyroid hormone supplementation of Beagle dogs with induced hypothyroidism stimulates hair growth.