陕西周至县猕猴桃的运输损坏研究

通过分析陕西猕猴桃自身的生理特性,并结合陕西周至县猕猴桃的包装形式及运输环境,找出猕猴桃运输损坏的原因,提出猕猴桃合理的运输方案,为快递企业生鲜水果的运输方式提供一定的理论参考。     

《机械制图》融合式教学模式在疫情下的实践1

面对突如其来的疫情，教师们主动担当、积极作为，“停课不停学”。应对疫情，学生学习环境复杂，必须认真思考，对课程进行教学改革势在必行。机械制图课程组研究分析了目前教学实情，在教学模式、教学方法和课程组织等进行一系列改革实践，将融合式教学模式应用于《机械制图》教学与助学，结合课程特点，应用网络线上教学模式，开展居家学习，实现课堂内外的融合，网络线上线下教学的融合。提高了学生自主学习，激发了学生积极思维和参与教学活动，教学效率和教学质量都取得了较好的效果。     

腐蚀管道剩余寿命的性能衰减模型研究

管道在长期的运行过程中，由于介质和土壤的腐蚀性，管材的微塑性变形、结构转变和渗氢等。不仅会使管道出现各种腐蚀损伤，而且还存在着老化效应和氢化作用，导致管材的脆变并改变材料的塑性，使机械性质参数发生衰退，从管材性能衰减和腐蚀损伤角度研究了管道的剩余寿命，提出了根据结构承载能力的极限值确定塑性变形时工作寿命的方法，为了确定剩余使用寿命，对剪切损伤率和屈服性能比等概念进行定义，在掌握管材金属剪切损害率和屈服性能比的时间特性基础上，建立了剩余寿命计算模型。并给出了算例。     

钢筋混凝土结构锈蚀损伤定位

对钢筋混凝土结构锈蚀损伤定位进行了研究,以频率变化平方比作为锈蚀损伤参数,从理论上证明该参数是锈蚀损伤位置的函数。锈蚀钢筋混凝土结构试验结果表明预测的损伤位置和实际的损伤位置较一致,模态参数用于检测混凝土结构构件中的损伤,为大型结构的鉴定和评估提供了新的途径。     

药物防治蝇害的研究进展

蝇害已经成为危害规模化畜禽养殖的重要问题。文章回顾了防治蝇害的三代杀虫剂的发展过程和存在的问题 ;展望了作为新一代环境友好防治蝇害药物的昆虫生长调节剂的开发前景。     

重油催化再生器典型缺陷安全评定

应用断裂力学理论和实验技术,测定了重油催化再生器材料及焊缝的力学性能和断裂韧度值,按照《压力容器缺陷评定规范》(CVDA-84)对再生器下部筒体典型缺陷进行了评定。经分析计算获得了重油催化再生器下部筒体各部位各种裂纹类型缺陷的允许尺寸,可将其作为重油催化再生器无损检测时的缺陷评定指标。     

Variation in the level of grain defect light flecks and spots on cattle hides.

The occurrence of hide damage light flecks and spots was determined on tanned hides from 28 herds during a period of 8 to 12 months. Light flecks and spots are described as small areas of grain loss up to 3 mm in diameter that are seen on dyed crust cattle leather. Damage was found on 75.8% of all hides. The neck and shoulders were the anatomical region with the highest prevalence of damage. Sixty-eight per cent of all hides had light flecks and spots in this region. The forelimbs and dewlap were the anatomical region with the second highest occurrence with a prevalence of 39.1%. This distribution corresponded to the known distribution of lice in cattle. No significant differences were observed in age, sex, prevalence of lice in the herd assessed in March or infestations with different lice species. The frequency of light flecks and spots varied significantly during the year. The frequency was highest in the late winter and early spring, decreased significantly during the summer and was lowest in the autumn. This variation supported the importance of lice in the development of light flecks and spots and suggested a relatively long healing period for the damages induced by lice.     

The effect of eradication of lice on the occurrence of the grain defect light flecks and spots on cattle hides.

The influence of an eradication programme for lice on the prevalence of light flecks and spots on cattle hides was studied in 33 dairy cattle herds during a period of two and a half years. Lice were eradicated from the main group of herds after 9 to 12 months and the quality of the hides before and after treatment was compared. Hides from slaughtered animals were collected during the study period, tanned and examined with special emphasis on the occurrence of the grain damage light flecks and spots. The prevalence of hides without light flecks and spots increased from 24.2% before treatment to 61.6% after treatment. The prevalence of hides free from the damage increased significantly in all examined anatomical regions. The improvement in hide quality was most marked in the shoulders and neck region which corresponded to the major predilection site of cattle lice. The prevalence of hides with light flecks and spots started to decrease in the first period (2-40 days) after eradication. The changes after treatment suggested that most healing process took place over a period of about 4 months. The eradication programme eliminated the seasonal variation in the prevalence of light flecks and spots which was present before treatment.     

2004年冬成都市外来园林植物冻害调查及建议

作者2005年春调查了成都市外来园林植物冻害情况,发现：（1）外来园林植物受冻害影响较为普遍,41种植物在不同程度上受害;（2）冻害影响存在区域差异,郊区冻害比城区严重.分析了冻害原因,并对园林植物引种提出建议.