Comparative Immune Efficacy of Native Inactivated and Attenuated Vaccines for Porcine Reproductive and Respiratory Syndrome Virus over 2 Consecutive Years

Porcine reproductive and respiratory syndrome(PRRS) was first described in the United States in1987. This syndrome was characterized by abor-tion, premature farrowing, stillborn and mummi-fied pigs, as well as respiratory disease with chron-ic poor performance of nursing and weaned pigsand death. PRRS has been recognized worldwideand is considered to be an economically importantglobal disease since its emergence[1]. Several pro-tocols such as enhancing management, quarantine,disinfection, …     

有限元分析在波纹管平面失稳中的应用

为了研究波纹管平面失稳临界压力，利用有限元分析法对波纹管进行了应力分析和平面失稳临界压力计算，并与试验结果进行了比较。结果表明，采用非线性屈曲分析得到的平面失稳临界压力与试验实测失稳临界压力较接近，其精确性高于理论计算的结果，可为波纹管稳定性设计计算提供参考。