用背角准弹散射研究近库仑势垒能区重离子核反应

利用背角准弹散射的方法开展了近库仑势垒（近垒）能区重离子核反应机制的研究。高精度测量了深垒下能区16O+152,154Sm、184W、¹⁹⁶Pt和²⁰⁸Pb等体系的背角准弹散射激发函数，用耦合道计算抽取了核势的表面弥散参数，结果表明考虑耦合道效应得到的表面弥散参数值正常。基于背角准弹散射势垒分布对核结构的敏感性，尝试用深垒下能区16O+152Sm、170Er和174Yb等体系的背角准弹散射来抽取形变靶核的十六极形变参数，所抽取值与已有结果趋势一致，说明了该方法的可行性。此外，研究了弱束缚核体系的破裂效应，其表现为背角准弹势垒分布较全熔合势垒分布向低能移动，所得结果进一步说明势垒分布同时含有核结构和核反应机制的信息。     

On globally stable adaptive control providing l 1 tracking performance for linear discrete-time systems

Existing adaptive control algorithms at best guarantee that the tracking error is a l ₂ sequence. This paper presents globally stable adaptive control algorithms for linear discrete-time systems providing l ₁ tracking performance. Two algorithms with different degree of complexity are proposed, one for the case of known control directions, and a separate algorithm for the case of unknown control directions. It is demonstrated that in both cases the tracking error is l ₁ sequence, while the input and output signals are uniformly bounded.     

鄂尔多斯盆地延长组致密砂岩储层微观孔喉特征差异及其成因

为分析不同沉积与成岩作用改造下致密砂岩储层的孔喉类型及其参数差异，利用物性、铸体薄片、扫描电镜、恒速压汞、图像粒度与X衍射实验结果，对比了鄂尔多斯盆地合水地区延长组长8储层和薛岔地区延长组长6储层的孔喉类型，定量评价了孔喉参数，揭示了形成原因。结果表明，合水地区长8储层孔隙更为发育，粒间孔、溶蚀孔、晶间孔和微孔、弱压实成因缩颈状喉道和溶蚀成因、粘土胶结成因管束状喉道含量高；薛岔地区长6储层的孔隙类型少且发育程度较差，压实成因片状、弯片状喉道含量高。两个区块的孔隙参数差异小，喉道参数差异大，前者大喉道更为发育，喉道差异大，孔喉比大，对渗透率起贡献的喉道分布范围更宽。相同渗透率条件下，前者的平均喉道半径、主流喉道半径和孔喉比大于后者。沉积水动力条件、粒度、碎屑组分、填隙物、成岩作用类型及其改造程度是两个研究区孔隙发育程度不同、喉道类型差异和孔喉参数表现出不同特征的主要原因。     

Novel model reference adaptive control architecture using semi‐initial excitation‐based switched parameter estimator

This paper is a generalization of the recently developed techniques of initial excitation (IE)–based adaptive control with an introduction to the definition of semi‐initial excitation (semi‐IE), a still more relaxed notion than IE. Classical adaptive controllers typically ensure Lyapunov stability of the extended error dynamics (tracking error + parameter estimation error) and asymptotic tracking, while requiring a stringent condition of persistence of excitation (PE) for parameter convergence. Of late, the authors have proposed a new adaptive control architecture, which guarantees parameter convergence under the online‐verifiable IE condition leading to exponential stability of the extended error dynamics. In earlier works, it has been established that the IE condition is significantly milder than the classical PE condition. The current work further slackens the excitation condition by proposing the concept of semi‐IE. The proposed adaptive controller is proved to ensure convergence of the parameter estimation error to a lower‐dimensional manifold under the weaker semi‐IE condition, while the stronger condition of IE guarantees convergence of the parameter estimation error to zero. The designed algorithm is shown to improve transient response of tracking error sufficiently in contrast to conventional adaptive controllers.     

An enhanced state estimation for linear parabolic PDE systems with mobile sensors

This paper studies an enhanced state estimation problem of distributed parameter processes modeled by a linear parabolic partial differential equation using mobile sensors. The proposed estimation scheme contains a state estimator and the guidance of mobile sensors, where the spatial domain is decomposed into multiple subdomains according to the number of sensors and each sensor is capable of moving within the respective subdomain. The state estimator is desired to make the state estimation error system exponentially stable while providing an performance bound. The mobile sensor guidance is used to enhance the transient performance of the error system. By the Lyapunov direct technique, an integrated design of state estimator and mobile sensor guidance laws is developed in the form of bilinear matrix inequalities (BMIs) to meet the desired design objectives. Moreover, to make the performance bound as small as possible, a suboptimal enhanced state estimation problem is formulated as a BMI optimization one, which can be solved via an iterative linear matrix inequality algorithm. Finally, numerical simulations are given to show the effectiveness of the proposed method.     

松辽盆地伏龙泉断陷边界断层构造反转率

盆地边界断层通常为同沉积断层，同沉积断层活动时间相对短且具有间歇性，地层沉积时间相对较长，这决定了断陷盆地的地层分布格局。通过分析同沉积断层理论模式，认为断陷缓坡带地层厚度与边界断层下盘厚度相当，边界断层下盘通常缺失与上盘对应的地层，可选择断陷盆地缓坡带地层厚度代替边界断层下盘厚度，建立虚拟下盘厚度格架，然后运用位移-距离曲线等方法对边界断层开展定量研究。伏龙泉断陷位于松辽盆地东南部，为东断西超的半地堑盆地，发育4条边界断层，依次控制了4个沉积次洼，4条边界断层的活动强度和反转程度存在差异。伏龙泉断陷经历了断陷期、拗陷期、反转期三个主要的构造期次，分别对应于边界断层强烈活动、停止活动、反转活动3个演化阶段，发生于白垩纪末的反转活动使得边界断层再次活化，形成油气运移通道，深层油气向上运移到浅层圈闭中，形成次生油气藏。通过定量计算伏龙泉断陷各边界断层的反转率，结合油气富集规律认识，认为反转率适中的区域最有利于次生油气藏的形成和保存。     

破碎围岩回采巷道锚网索支护参数优化

针对镇城底煤矿8"煤层工作面巷道围岩破碎、支护困难等问题,分析了原有巷道支护方式失效的原因,进而针对性的优化了巷道支护参数,采用①20 mm X 2500 mm左旋螺纹钢锚杆,①17.8 mm X 6500 mm锚索,并进行了验算。最后通过现场实测巷道顶板离层量得到有效的控制,实现了安全髙效开采。     

孤网模式下水轮机调节系统参数敏感性分析

鉴于参数敏感性分析是水轮机调节系统稳定性研究的重要内容,以XLD电站中某机组的孤网运行模式为例,基于轨迹灵敏度指标,在机组负载扰动和参数摄动条件下研究了系统主要变量对参数变化的敏感程度。结果表明,孤网模式下不同参数变化对不同变量的影响不同,系统变量对发电机参数的敏感性要大于对随动系统参数的敏感性。     

基于决策树的堆芯物理参数预测研究

反应堆堆芯核设计涉及大量方案的搜索与详细计算，缩短方案搜索时间有利于提高核设计效率。数据挖掘技术通过对大量数据进行学习与模式识别，可实现核设计方案物理参数的快速预测，更快地筛选出可行的备选堆芯方案。本文基于数据挖掘的决策树4种算法：C4.5、RepTree、Random Forest及Random Tree，在计算时以燃料富集度、含可燃毒物燃料棒数量及含量作为自变量，以寿期内k_eff不均匀系数偏差（KUCD）、径向功率不均匀系数偏差（RPNCD）、径向中子通量不均匀系数偏差（RFNCD）、堆芯寿期（CL）作为目标函数，构成目标函数符合度（CPF），利用大量已知核设计参数的组件及堆芯设计方案作为数据挖掘训练集，构建数据挖掘模型，并用于对未知核设计参数的组件方案集合（测试集）进行CPF快速预测。结果表明，4种算法利用训练集构建数据挖掘模型的时间在0.6 s以内，各算法的交叉验证精度均在0.7以上，其中C4.5算法对CPF预测精度最高；对测试集方案的核设计参数预测中，单个方案的预测时间均在0.9 s以内，而Random Forest算法对CPF等于4的预测效果最好。     

On a class of mixed EWMA-CUSUM median control charts for process monitoring

Monitoring of any manufacturing, production, or industrial process can be controlled and improved by removing these special cause of variations using control charts. Shewhart-type control charts are effective to control a large amount of special variations, whereas, cumulative sum (CUSUM) and exponentially weighted moving average (EWMA) charts detect small and moderate variations efficiently in the process parameters. Monitoring of location parameter can be done with mean control charts under the assumption that the parameters are known or correctly estimated from in-control samples and data are free from outliers (but in practice data occasionally have outliers). In this study, we have proposed generalized mixed EWMA-CUSUM median control charts structures for known and unknown parameters based on auxiliary variables for detecting shifts in process location parameter. The proposed charts are compared with the corresponding charts for the mean, based on contaminated and uncontaminated data. Different performance measures are used to evaluate the performance of proposed control charts and revealed through results that the median-based charts are more sensitive to detect a shift in process location parameter in the presence of outliers. An illustrative example using real data is also shown for practical consideration.