Wavelet domain adaptive filtering algorithm for removing the seamless pipe noise contained in the magnetic flux leakage data

With the widespread application and fast development of gas and oil pipeline network in China, the pipeline inspection technology has been used more extensively. The magnetic flux leakage （MFL） method has established itself as the most widely used in-line inspection technique for the evaluation of gas and oil pipelines. The MFL data obtained from seamless pipeline inspection is usually contaminated by the seamless pipe noise （SPN）. SPN can in some cases completely mask MFL signals from certain type of defects, and therefore considerably reduces the detectability of the defect signals. In this paper, a new de-noising algorithm called wavelet domain adaptive filtering is proposed for removing the SPN contained in the MFL data. The new algorithm results from combining the wavelet transform with the adaptive filtering technique. Results from application of the proposed algorithm to the MFL data from field tests show that the proposed algorithm has good performance and considerably improves the detectability of the defect signals in the MFL data.     

深部巷道构造应力作用下岩爆过程的数值模拟

针对深部巷道岩爆现象,结合华丰煤矿深部开采的冲击地压问题,采用FLAC-Dynamic进行了深部巷道岩爆动力学计算分析.计算结果表明,发生岩爆时,巷道围岩的速度曲线和加速度曲线出现突变.在水平构造应力的作用下,巷道可能岩爆的过程是先从巷道的两帮开始,然后迅速扩展到巷道的顶、底板的过程.     

基于EM迭代算法的CDMA多用户检测

针对CDMA最优多用户检测的难解性,结合CDMA通信的实际特点,利用EM迭代算法适宜组合求解,运算简单等特点,提出了一种基于EM迭代算法的多用户检测方法,仿真实验结果表明本方法大大降低最优多用户检测器的计算复杂度,同时达到了次最优的检测效果。     

Improving biocontrol activity of Pseudomonas fluorescens through chromosomal integration of 2,4-diacetylphloroglucinol biosynthesis genes

Antibiotic 2,4-diacetylphloroglucinol (2,4-DAPG) produced by Pseudomonas fluorescens CPF-10 and 2P24 is a principal factor enabling bacteria to suppress plant diseases caused by soilborne pathogens. In this study, a 2,4-DAPG biosynthesis locus phlACBDE cloned from strain CPF-10 was assembled into a mini-Tn5 transposon and introduced into the chromosome of P. fluorescens P32 (2,4-DAPG-), CPF-10 and 2P24 to construct the 2,4-DAPG overproducing derivatives P32-38, CPF10-9 and 2P24-48, respectively. All the transgenic strains showed an enhanced antibiosis capacity against plant microbial pathogens in vitro and two strains, P32-38 and CPF10-9, provided significantly better protection against wheat take-all disease caused by Gaeurnannomyces graminis vat. tritici and tomato bacterial wilt caused by Ralstonia solanacearum in greenhouse. Comparedto their parental strains, the 2,4-DAPG overproducing derivatives colonized to the same extent on the wheat tips in the autoclaved soil, but developed larger populations in natural soil. These results indicated that production of antibiotics 2,4-DAPG by biological control pseudomonads can contribute not only to their disease suppression capacities but also to the ecological competence in the resident microflora. Our research also suggests that it is a realistic approach to improve biocontrol capacity of P. fluorescens through the genetic modification of its antibiotic 2,4-DAPG production.     

面向伙伴选择的模糊Markov博弈控制及仿真研究

针对不确定条件下的伙伴选择决策问题,把自适应模糊控制系统理论及神经网络理论引入到Markov博弈中,提出一种基于多智能体的伙伴选择模糊控制模型。该模型引入基于ANFIS和神经网络的模糊神经网络,实现了一种全新的进行值函数逼近的梯度下降Q学习的算法。并应用该模型对伙伴选择问题进行研究,对多影响因素进行FNN学习,将输出量作为标准Markov博弈模型的输入量,得到影响的策略,最后研究了一个应用实例,利用具体历史数据对建模方法和模型进行了验证和分析。     

法兰夹紧作用下金属分层锯片的振型及降噪效果

圆锯片的振动是金属锯切噪声的主要声源之一。法兰夹紧作用下金属圆锯片结构的横态密集,各阶阻尼比很小,且主要为节直径横态振动引起的声辐射。欲抑制众多的敏感模态应设法增加圆锯片的结构阻尼。基于干摩擦阻尼耗能机理的分层圆锯片能有效地改善锯片的动态特性,可使金属锯切噪声级降低12dB(A)左右。     

用Z80-SIO配接20mA电流回路通信线的技术方案与实现

本文就Z80—SIO配接20mA电流回路通信线的硬件接口技术进行了一些讨论,并介绍了一种实现方案。     

洪山殿矿区边缘断裂带岩组运动学和动力学分析

本文分析了湖南省洪山殿矿区边缘断裂带岩组运动学特征和动力学特征,阐述了断裂带的活动性质和运动方式,并得出了断裂带具有多期活动性的结论。图8,表3,参考文献4。     

醇酸树脂反应釜的失效模式及其影响分析

本文介绍了失效模式及其影响分析的定义、分类及基本构成，并概括了其分析步骤。文中介绍了醇酸树脂反应釜各部件的功能，讨论了醇酸树脂反应釜的潜在失效模式、可能导致的后果及其原因；依据严重度、频度数、不易探测度及风险顺序值的量化标准，对各个项目进行了量化分析，对超出标准的项目提出了整改措施。对于FMEA方法在醇酸树脂反应釜中的应用会大大弥补当前存在的危害进行全面的识别和分析，并提供有效的信息和数据指导生产，能够为保障安全生产、制定维护维修决策以及优化成本效益比率提供强有力的数据支持。