期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
环模模孔参数对颗粒饲料加工质量及肉鸡生长性能的影响 被引量:8
1
作者 王昊 于纪宾 +2 位作者 于治芹 李俊 李军国 《动物营养学报》 CAS CSCD 北大核心 2017年第9期3352-3358,共7页
本试验旨在研究环模模孔参数对颗粒饲料加工质量及肉鸡生长性能的影响。通过固定模孔直径(3mm)改变模孔长径比(6∶1、8∶1、10∶1)以及固定模孔长径比(10∶1)改变模孔直径(3.0、3.5、4.0mm),生产5种不同直径及硬度的肉鸡颗粒饲料。选取... 本试验旨在研究环模模孔参数对颗粒饲料加工质量及肉鸡生长性能的影响。通过固定模孔直径(3mm)改变模孔长径比(6∶1、8∶1、10∶1)以及固定模孔长径比(10∶1)改变模孔直径(3.0、3.5、4.0mm),生产5种不同直径及硬度的肉鸡颗粒饲料。选取864只体重相近的21日龄爱拔益加(AA)肉鸡,随机分成6组,每个组8个重复,每个重复18只。Ⅰ~Ⅴ组分别饲喂模孔直径和长径比分别为3.0mm和6∶1、3.0mm和8∶1、3.0mm和10∶1、3.5mm和10∶1、4.0mm和10∶1的颗粒饲料;Ⅵ组分2阶段饲喂,22~35日龄饲喂模孔直径和长径比为3.0 mm和10∶1颗粒饲料,36~42日龄饲喂模孔直径和长径比为4.0mm和10∶1颗粒饲料。试验期21d。结果表明:1)模孔直径相同时,颗粒硬度随着模孔长径比的增加而极显著提高(P<0.01);模孔长径比相同时,颗粒硬度随着模孔直径的增加而极显著提高(P<0.01)。各组颗粒耐久性指数(PDI)无显著差异(P>0.05),且都高于95%。2)模孔直径相同时,随着颗粒硬度的增加,肉鸡终末体重、平均日增重均逐渐降低,料重比逐渐升高。Ⅰ组的终末体重和平均日增重显著或极显著高于Ⅲ组(P<0.05或P<0.01),Ⅰ组料重比显著低于Ⅱ、Ⅲ组(P<0.05)。3)模孔长径比相同时,各组终末体重、平均日增重和平均日采食量均无显著差异(P>0.05);随着颗粒直径的增加料重比逐渐降低,且Ⅲ组料重比显著高于Ⅴ组(P<0.05)。综上所述,模孔长径比和直径的增大均会显著提高颗粒硬度。在一定范围内,提高颗粒硬度会使肉鸡终末体重和平均日增重降低,料重比升高,而增大颗粒直径则会使料重比降低。 展开更多
关键词 环模参数 肉鸡 颗粒饲料 加工质量 生长性能
在线阅读 下载PDF
Ventilation control of tunnel drilling dust based on numerical simulation 被引量:11
2
作者 JIANG Zhong-an WANG Ya-peng MEN Li-guo 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第5期1342-1356,共15页
In order to control the dust pollution produced by air leg rock drill in the trolley area during the excavation of long-distance single ended tunnel,the full-scale physical model of working face was established by usi... In order to control the dust pollution produced by air leg rock drill in the trolley area during the excavation of long-distance single ended tunnel,the full-scale physical model of working face was established by using FLUENT software,and the numerical simulation analysis of tunnel drilling ventilation and dust removal parameters was carried out.The results show that it is difficult to control the dust pollution of the face by conventional ventilation,and the drilling dust is distributed in the range of 10 m from the face;after the introduction of the long pressure and short suction ventilation scheme,when the ratio of compressed air volume to exhaust air volume is 0.72,the height of the pressure fan is 2.5 m,the distance between the pressure fan and the palm face is 20 m,and the exhaust fan is 12 m away from the palm,the dust concentration control efficiency of the working face is increased by about 60%.Therefore,in the similar long-distance single head tunnel construction,it is appropriate to adopt the dust removal method of long-distance short suction and exhaust fan to ensure the working environment. 展开更多
关键词 dust pollution working environment numerical simulation ventilation parameters
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部