不同模式孵化器对海兰褐父母代种蛋孵化性能的影响研究

为比较单阶段大箱体孵化器与多阶段巷道式孵化器对海兰褐父母代种蛋孵化性能的影响,将279 804个来源于37~45周龄海兰褐父母代的合格种蛋随机分成两组,单阶段组共入孵129024个、多阶段组共入孵150780个。两组种蛋同一天入孵,出壳后分别统计两组各周龄的孵化率及1日龄健母雏的体重和体长等。结果显示:随着周龄的增加,单阶段组受精蛋孵化率和受精蛋健母雏率更高。在43和45周龄,单阶段组受精蛋孵化率极显著高于多阶段组(P<0.01),受精蛋健母雏率显著高于多阶段组(P<0.05);单阶段组1日龄健母雏的体重和体长极显著高于多阶段组(P<0.01)。研究表明:不同孵化模式对海兰褐父母代种蛋孵化性能有影响;使用单阶段大箱体孵化来自43周龄后海兰褐父母代的种蛋,可同时获得更高的受精蛋孵化率和健母雏率及更优的生产性能。

一种四层叠压带双弹舌件的模具改进

介绍一种四层叠压带双弹舌端子件的模具改进,模具经过改进后避免许多缺陷。

Research on overall assembling and welding process of steel box girder tuyere blocks of Taizhou Bridge

This article presents in detail the assembling and welding process technique of the steel box girder tuyere blocks of Taizhou Bridge. The application of this process technique effectively solves the problem of welding stress release in tuyere block assembling and welding without increasing the number of turns of the blocks and overhead welding, thus avoiding possible structural deformation due to excessive accumulation of internal welding stress, greatly reducing the repeated deformation and correction work during assembling and welding, and ensuring the weld seam quality and overall dimensions of tuvere blocks of Taizhou Bridze.