新型双面铸造冷却方式对5154铝镁合金线材组织及性能的影响

为提高5154铝镁合金线材的综合性能,采取不同铸造冷却方式对5154铝合金线材进行试验研究,采用扫描电子显微镜、拉伸力学测试仪及电阻测试仪对合金材料的组织和性能进行研究,结果表明:采用新型双面冷却工艺生产的5154铝镁合金晶粒细小且均匀,合金晶粒得到了细化;其制备的φ8 mm铝镁合金铸杆抗拉强度高达242 MPa,断裂伸长率为22%,导电率为36%IACS,比传统单面冷却方法所制备的样品指标分别提高了7.1%、21.1%和4.3%.

稀土Y对6061铝合金铸态组织及性能的影响

采用光学显微镜、扫描电子显微镜电镜、拉伸力学测试仪,研究了在6061铝合金中加入稀土Y后,材料铸态组织和性能的影响。结果表明:微量Y元素加入6061铝合金后,铸态组织得到改善,添加0.3 wt.%Y后,晶粒尺寸达到较小值(86.7μm),同时能够有效地形成AI_(3)Y相,在基体中形成弥散强化,部分稀土相在晶界处析出,其制备的6061铝合金棒材的抗拉强度高达360MPa,断裂伸长率为14%,比未添加提高30.43%和5%,断裂方式为韧窝断裂与准解理断裂复合形式。

石墨烯纳米化增强铝镁合金线材料制备技术探讨

针对现有铝镁合金丝线存在丝线硬度、韧性、抗拉压强度等物理性能普遍偏低而电阻率偏高等电学问题,采取石墨烯纳米化增强铝镁合金线材料的技术方法,采用功能材料纳米化与纳米复合负载晶粒细化协同效应方式改善铝镁合金线材料性能,探索通过石墨烯纳米化增强铝镁合金线材料的可控制备使材料综合性能达到最优的普适方法和途径。

肝脏磁共振图像分割方法的研究

肝脏磁共振图像分割是诊断肝脏疾病的重要手段之一,偏移场是肝脏磁共振图像中通常存在的灰度不均匀现象,导致图像分割效果不理想。采用正则化相邻局部灰度聚类算法对肝脏磁共振图像进行偏移场矫正,在能量函数中加入辅助变量来解决非凸隶属函数,通过迭代计算得到最优偏移场矫正结果,并采用基于水平集的图像分割算法对矫正后图像进行分割。通过差值图像、灰度直方图、Jaccard参数和Dice参数来评价算法的性能及图像分割效果,并与非参数非均匀归一化变量(N4)算法进行对比分析。实验结果表明,相邻局部灰度聚类算法引入总变分项进行偏移场矫正后,图像与原始图像差值更大,灰度分布更均匀,图像分割结果更准确,便于医生进行病理观察及诊断。

Effect of Eliminated the Breeding Pigs with Unqualified CSFV Antibody on Sows' Reproductive Performance and Pigs' Growth Performance

[Objective] The aim was to explore the effect of eliminated the breeding pigs with unqualified CSFV antibody on sow's reproductive performance and pig's growth performance so as to provide a scientific basis for the eliminating of the breeding pigs with unqualified CSFV antibody in large-scale pig farms.[Method] Serum samples from three scale pig farms were collected and tested with HerdChek CSFV-ELISA kit,then provided a certain scientific basis for scale pig farm to eliminate the unqualified(antibody blocking rate<50%)breeders after booster immunization.[Result ] After eliminating the breeding pigs with unqualified CSFV antibody,the average litter number of piglet in three pig farms(A,B,C)were increased by 0.29(P<0.05),0.40(P<0.01),0.39(P<0.01)respectively;the average number of survival piglets were increased by 0.54(P<0.01),0.35(P<0.01),0.62(P<0.01)respectively;the average litter number of weaned piglets were increased by 0.65(P<0.01),0.71(P<0.01),0.81(P<0.01)respectively.The difference in weight gain of piglet at 30-60 d of age was extremely significant(P<0.01),but inconspicuousness for the swine pregnancy rate,the survival rate of weaned piglet and piglet at 30-60 d of age.[Conclusion] The eliminating the breeding pigs with unqualified CSFV antibody can significantly improve the performance of breeder and piglets.