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文中在深入分析免疫原理的基础上,提出了一个分层检测的分布式入侵检测系统模型。模型采用提取检测规则库中的规则生成自动匹配的四层检测规则集,经反向筛选后分别注入对应检测层的移动检测代理(MDA),MDA迁移到各检测代理子结点处协同完成入侵检测和响应,实现免疫特性。具有这样免疫特性的多代理能对大流量的分布式网络进行分层检测和响应,能在局部和全局的不同层次上检测入侵攻击,具有较好的自适应性、可扩展性和智能性。 相似文献
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河口节制闸下淤积及冲淤效果耦合模型计算 总被引:3,自引:0,他引:3
在潮汐作用下河口地区具有挡潮功能的节制闸闸下引河泥沙淤积现象十分普遍,泥沙淤积严重影响了其行洪排涝能力,危害极大.因此,研究闸下淤积规律、探讨科学的清淤措施具有重要的工程实践意义.分析闸下淤积规律,并预估了闸下淤积,在吸收经验模型和水沙模型的优点的基础上,建立了二者的耦合模型,模拟了部分开闸冲淤时闸下引河水沙运动.该模型与平面二维水沙模型相比简化了计算,且其计算精度满足工程应用的要求.通过计算比较多孔闸闸门全开及部分开闸的冲淤效果表明:对闸门上下水头差和闸内水量较小、闸下引河较短的情况,采取开启中孔闸的冲淤方式比多孔全开的冲淤效果好. 相似文献
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大黄油菜是青藏高原特有的一个白菜型油菜地方品种,种皮颜色鲜黄.已知大黄油菜的黄籽性状受到1对隐性基因(Brsc1)控制,且该基因被定位于白菜型油菜的第9连锁群上.为获得更多与种皮色泽紧密连锁的分子标记以及共显性标记,本研究利用大黄油菜和褐籽白菜型油菜09A-126为亲本构建BC1分离群体和F2群体,利用AFLP与BSA相结合的方法,通过筛选256对引物结合,共获得5个与种皮色泽连锁的AFLP标记.5个特异AFLP片段分别被回收、克隆、测序,并与白菜型油菜基因组序列进行同源比对,均与A09染色体表现同源.将5个AFLP标记成功转化成5个SCAR标记,用F2群体对SCAR标记进行检测,筛选到1个共显性标记. 相似文献
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Haojun?Xu Minfang?An You?Lv Li?ZhangEmail author Zongbao?WangEmail author 《Polymer Bulletin》2017,74(3):721-736
The ultrahigh molecular weight polyethylene (UHMWPE) fibers were obtained directly from the industrial production line. Two-step industrial hot-drawing-to-specific-drawing ratios were carried out at the temperature of 120 and 130 °C, respectively. Small-angle X-ray scattering (SAXS) measurements using synchrotron radiation were applied to study the evolution of kebab structure and the formation of shish structure. The slight increase of long period and the rapid decrease of lateral sizes indicated the destruction of original lamellae which was accomplished by chain slip resulted in the orientation of lamellae to form shish structure. The decrease of average shish length was explained that the formed new shish structure had shorter shish length than the original shish at the early stage with the high concentration of spinning solution. Wide-angle X-ray diffraction (WAXD) measurements were performed to explore the changes of the degree of orientation of the crystals. It was found that the elevated drawing temperature was benefited to the evolution of the orientational order. The DSC result confirmed the evolution of shish–kebab structure through the melting behavior. 相似文献