运载火箭发射场数字合练技术

运载火箭发射场数字合练是火箭、发射台、发射场在实物见面前通过计算机进行的一次虚拟演习,对运载火箭研制具有重要意义和工程价值。简述了以运载火箭为对象,开展的一系列虚实孪生模型构建、合练场景二次定义、试验过程仿真、综合计算约束分析及虚拟交互操作等关键技术研究,给出了贯穿火箭运输进场至射前的发射场全流程机械接口数字合练试验方法,以及运用在型号研制中所取得的成效。某火箭实物产品机械合练中未出现干涉不协调问题,证明了该方法切实有效。

Analysis of the function of D279N mutation of VP2 of infectious bursal disease virus

Infectious bursal disease virus（IBDV）is responsible for the highly contagious infectious bursal disease of chickens.Further understanding the gene-function is necessary to design the tailored vaccine.The amino acid residue 279,located on strand P_F of VP2,is one of the three residues that have been reported to be involved in cell-tropism but with some inconsistency.In this study,to further clarify the amino acids involved in the cell tropism of IBDV,a series of mutations about residue 279were introduced into the VP2 of vv IBDV Gx strain.With the reverse genetic system,we found single mutation of D279N,double mutations of D279N/A284T or Q253H/D279N were not enough to adapt IBDV to chicken embryo fibroblast（CEF）cell.To evaluate whether residue 279 could influence the replication and virulence of IBDV,the virus r Gx HT-279 with three mutations（Q253H/D279N/A284T）was rescued and evaluated.Results showed that the mutation of residue 279 in VP2had no efficient effects on both the replication efficiency in vitro and the virulence to SPF chickens of IBDV.In summary,the results demonstrated that residue 279 of VP2 did not contribute efficiently to cell tropism,replication efficiency,and virulence of IBDV at least in some strains.These findings provided further information for understanding the gene function of IBDV.

协商民主视角下邻避设施选址困境的治理路径--以杭州九峰垃圾焚烧厂为例

近几年,我国邻避设施选址陷入社会需求和公众反对的困境,根源在于多元主体有着不同的利益诉求。政府常用的"封闭决策,事后维稳"的治理模式并不能从根本上解决邻避设施选址困境问题。协商民主承认和尊重多元化的利益诉求,并通过多元主体之间的对话协商达成共识,为解决邻避困境提供了全新的思路。正是基于协商民主的理念,杭州市政府构建了多元主体之间的开放协商的决策机制、平等有效的风险沟通机制和理性包容的互动机制,从而使杭州九峰垃圾焚烧厂走出选址困境并得以在原址重建。这为我国邻避设施选址困境治理提供了一些有益的启示。