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ũҩ��ܷ���ƽ̨�������ʵ�� 总被引:1,自引:0,他引:1
农药是重要的农业投入品,农药产品质量直接关系到农业生产,是确保粮食增收、粮食安全的重要前提条件.目前,我国农药流通环节多,加之监管不到位,导致市场上出现许多不合格的农药产品,严重影响到粮食生产和生态安全.结合农药监管的实际需求,以规范农药市场,服务现代农业,加强农药产品质量安全监管水平为目标,围绕政府监管、诚信经营、放心溯源三条主线,构建农药监管服务平台,建立并完善农药监管信息采集、汇总、交互、分析和服务应用,实现农药准入、销售管理和溯源查询“三位一体”,实现全链条监管. 相似文献
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The paper proposes a reliable multicast protocol which is appropriate for real-time and interactive collaborative environment. The control tree and grouping mechanism are introduced to make error recovery localized, which can efficiently decrease the amount of packet stream on the backbone of network and the workload of host. Analysis shows that the protocol has perfect throughput and can be extended to very wide applications. 相似文献
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In this paper, the fundamental definitions, the affecting factors and the deterministic methods for the lifes of the high voltage electromagnetic instrument transformers are discussed. The relations among various lifes and their characteristics are also e 相似文献
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差错控制是保证组播可靠性的最基本技术,合理的缓存管理可以提高差错控制的效率.在随机可靠组播协议(RRMP)的基础上提出了改进的可靠组播协议(IRMP).IRMP使用短期缓存满足本地恢复需要,使用长期缓存满足远程恢复需要.在本地恢复时,利用组播发送重传请求,利用随机后退算法减少重复报文.在远程恢复时,使用指定修复节点(DRN)恢复丢失的报文.为了避免因DRN退出或故障导致长期缓存报文的丢失,提出了DRN转移的方法.在NS2平台上对IRMP和RRMP进行仿真的结果表明,IRMP有效地降低了缓存需求,减少了恢复时延,具有较高可扩展性. 相似文献
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针对一类连续线性区间系统,基于线性矩阵不等式,介绍一类能够将给出的连续区间系统的闭环系统的极点配置到指定圆盘中的状态反馈和输出反馈增益矩阵的设计方法.这类设计方法也包括分别基于执行器故障和传感器故障的可靠控制器的设计方法,基于矩阵的谱半径不大于自身的最大奇异值的理论以及矩阵的Schur补引理,将矩阵的最大奇异值限定后就能将矩阵的特征值限制在某个圆盘内,再将这种结果以线性矩阵不等式的形式表达出来.最后,给出的数值例子说明这类方法的可行性和有效性。 相似文献
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FENG Xian -gui 《保鲜与加工》2002,(7):133-136
Various defects and cracks may be produced in the welding process in natural gas pipeline.Under variable pressure of natural gas,the cracks will be propagated it may lead to break and invalidity.The effect of internal surface cracks are more serious.It has been researched that the propagation along radial direction of internel surface cracks in the natural gas pipeline.The fatig life of pipeline has been calculated.On the other hand,considering the size of cracks, pressure of gas and character of material are random variable,and by using reliability method,the fatig reliable life of pipeline has been determined.This method has some practical value in design, working and overhaul of pipeline. 相似文献
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