Optimization of Injection Parameters for Profile Control and Flooding in an Oilfield during High Water Cut Period

In order to improve the effect of water control and oil stabilization during high water cut period, a mathematical model of five point method well group was established with the high water cut well group of an Oilfield as the target area, the variation law of water cut and recovery factor of different injection parameters was analyzed, and the optimization research of injection parameters of polymer enhanced foam flooding was carried out. The results show that the higher the injection rate, the lower the water content curve, and the higher the oil recovery rate. As the foam defoamed when encountering oil, when the injection time was earlier than 80% of water cut, the later the injection time was, the better the oil displacement effect would be. When the injection time was later than 80% of water cut, the later the injection time was, the worse the oil displacement effect would be. The larger the injection volume, the lower the water content curve and the higher the recovery rate. After the injection volume exceeded 0.2 PV, the amplitude of changes in water content and recovery rate slowed down. The optimal injection parameters of profile control agent for high water content well group in Oilfield A were: injection rate of 15 m3/d, injection timing of 80% water content, and injection volume of 0.2 PV.

A modified similitude analysis method for the electro-mechanical performances of a parallel manipulator to solve the control period mismatch problem

Due to the discrete feature and performance limitation of the numerical controller,the control period sometimes cannot meet the constraints of the scaled model in similitude analysis,which brings the control period mismatch problem.The traditional similitude analysis methods are not able to solve this problem since the controller is treated as continuous system in these methods.This paper proposes a modified similitude analysis method to solve the control period mismatch problem,and the electro-mechanical performances of a 2-DOF parallel manipulator is predicted.Based on the model of dynamic and control system,most of the similitude laws are derived by taking the controller as continuous system.Then the transfer function of the controller in discrete form is established,and the similitude law related to control period is derived to figure out the cause of mismatch problem.The modified method,named long period equivalent,is proposed to solve the mismatch problem by using the least square method and superposition principles.Finally,the scaled model of the parallel manipulator is determined based on the modified similitude analysis method.

Flow Control over a Conical Forebody by Periodic Pulsed Plasma Actuation

The flow control mechanism of plasma actuators with periodic pulsed discharge to control the bi-stable vortices over a cone-cylinder is investigated. The actuators are installed on the leeward surface near the apex of a cone which has a semi-apex angle of 10°. The effectiveness of the plasma actuation under different free-stream velocities and angles of attack is analyzed. The pressure distributions over the conical forebody are measured by both steady and dynamic pressure transducers. The transient dynamic pressure distribution tends to gradually become steady as the free-stream velocity increases, that is, the pulsed actuation approximates a continuous one. Furthermore, the flow control effectiveness becomes less noticeable as the free-stream velocity or the angle of attack increases under certain controlling electrical parameters.

Reaction Selectivity Improvement for Reduction of Nitrobenzene in a Packed-Bed Electrode Reactor under Periodic-Current Control

Rectangular wave current control of the electrochemical reduction of nitrobenzene im-proves the selectivity for p-aminophenol(PAP) compared to direct current(d.c.) control at thesame average current density in a flow-by packed-bed reactor.Optimal increase in PAP selectivitycan be obtained at about a frequency of 50Hz and a duty cycle of 0.2.A mathematical model isset up to incorporate the effects of mass transfer,hydrogen evolution and double layer charging,and is solved using the Duhamel’s superposition principle and the modified Crank-Nicolson methodwith the upwind scheme.The conventional d.c.control cases are also calculated for comparison.Calculations can be applied to predict the reaction results under periodic current and d.c.control,but both display the same trends compared to experimental data.

H_∞ Controller Design for Networked Control Systems via Active-varying Sampling Period Method

这份报纸学习由使用一个活跃变化的采样时期方法与两导致网络的时间延期和包退学学生为联网的控制系统(NCS ) 设计 H 控制器的问题，在采样时期在一个有限集合切换的地方。一个新奇线性基于评价的方法被建议补偿包退学学生，和 H 控制器设计被使用多客观的优化方法论也介绍。模拟结果说明活跃变化的采样时期方法和线性基于评价的包退学学生赔偿的有效性。

Two Positive Periodic Solutions of Delay Functional Difference System with Feedback Control

由在一个锥上使用一条固定的点定理与反馈控制调查下列延期差别系统的二个积极周期的解决方案的存在

Study on High Accuracy Hybrid Controller for Periodic Motion Control

In order to realize high accuracy control for periodic motion,a hybrid controller with grey prediction was presented in this paper.Incorporating the grey prediction,repetitive control,and the traditional Proportional-Integral-Differential(PID)control,a design method of the grey prediction repetitive PID(GRPID)control algorithm was investigated,according to the characteristics of the periodic motion control.The hybrid control algorithm can estimate unsure parameters and disturbance of system using grey prediction,and compensate control in terms of the prediction results,and this may improve control quality and robustness of repetitive control for controlling periodic motion.An example was carried out to verify the feasibility of the controller.The simulation results show that this algorithm has better performances than that of the conventional repetitive control system.It indicates the presented control method is more suitable for control system of periodic motion.

Stability analysis of networked control systems with time-varying sampling periods

In this paper, we present an interval model of networked control systems with time-varying sampling periods and time-varying network-induced delays and discuss the problem of stability of networked control systems using Lyapunov stability theory. A sufficient stability condition is obtained by solving a set of linear matrix inequalities. In the end, the illustrative example demonstrates the correctness and effectiveness of the proposed approach.

Vibration analysis and active control of nearly periodic two-span beams with piezoelectric actuator/sensor pairs

The piezoelectric materials are used to investigate the active vibration control of ordered/disordered periodic two-span beams. The equation of motion of each sub-beam with piezoelectric patches is established based on Hamilton＇s principle with an assumed mode method. The velocity feedback control algorithm is used to design the controller. The free and forced vibration behaviors of the two-span beams with the piezoelectric actuators and sensors are analyzed. The vibration properties of the disordered two-span beams caused by misplacing the middle support are also researched. In addition, the effects of the length disorder degree on the vibration performances of the disordered beams are investigated. From the numerical results, it can be concluded that the disorder in the length of the periodic two-span beams will cause vibration localizations of the free and forced vibrations of the structure, and the vibration localization phenomenon will be more and more obvious when the length difference between the two sub-beams increases. Moreover, when the velocity feedback control is used, both the forced and the free vibrations will be suppressed. Meanwhile, the vibration behaviors of the two-span beam are tuned.

不同药剂与施药时期对辣椒炭疽病防治效果的影响

【目的】探明贵州辣椒炭疽病的适宜防治药剂和防治时期,为辣椒炭疽病化学防控提供依据。【方法】选取已登记的15种辣椒炭疽病防治药剂单剂(25%咪鲜胺EC、80%波尔多液WP、50%肟菌酯WG、22.7%二氰蒽醌SC、70%代森锰锌WP、40%百菌清SC、30%琥胶肥酸铜WP、80%克菌丹WG、22.5%啶氧菌酯SC、85%三氯异氰尿酸SPX、40%苯醚甲环唑SC、500 g/L氟啶胺SC、50%咪鲜胺锰盐WP、250 g/L嘧菌酯SC和25%吡唑醚菌酯SC)和1个混剂(40%苯甲•吡唑酯SC)为药剂处理,选取贵州辣椒炭疽病的3个主要致病菌菌株(C.scovillei GL 17-25、C.gloeosporioides GL 17-42和C.fructicola GL 17-147)为防治对象,采用菌丝生长抑制法和离体果实接种法对药剂进行初筛,通过田间试验进一步验证适宜的药剂和防治时期。【结果】25%咪鲜胺EC、50%咪鲜胺锰盐WP、70%代森锰锌WP对3种辣椒炭疽病菌的菌丝生长抑制率均为100.00%;离体果实接种试验表明,除70%代森锰锌WP外,各药剂的平均预防效果均高于治疗效果,25%咪鲜胺EC对3个菌株的预防和治疗效果最好,平均值分别为72.48%和60.01%,其次为25%吡唑醚菌酯SC(43.53%和30.36%)。相比发病中期用药,发病初期用药的病情指数低、防效高,25%吡唑醚菌酯SC和40%苯甲•吡唑酯SC的防效显著(P<0.05)高于25%咪鲜胺EC,前两者发病初期用药的防效分别为86.99%和88.59%,发病中期用药防效分别为50.87%和45.48%。【结论】25%吡唑醚菌酯SC和40%苯甲•吡唑酯SC能有效防治辣椒炭疽病,防治时期以发病初期为佳。

深部极松软围岩沿空巷道稳定性控制及应用

针对深部高应力作用下极松软围岩变形量大、破碎程度高、巷道难支护等问题,以丁集煤矿1232(3)沿空巷道为工程背景,采用数值模拟、现场监测和井下试验相结合的方法,对深部高应力极松软围岩沿空巷道破坏特征及阶段性控制原理和技术进行研究。结果表明:随着距巷道迎头距离的不断增大,巷道两帮应力的不对称性逐渐增大,实体煤侧应力峰值为37.18 MPa大于煤柱侧35.21 MPa,1242(3)终采线50 m范围内存在应力集中,最大达33 MPa,巷道围岩塑性区发育程度为煤柱帮大于实体煤帮大于顶底板;从巷道掘进过程中所经历的复杂围岩变化过程,将全巷道划分为5种典型的围岩变化阶段来分析围岩变形破坏特征和破坏机理,揭示了在高应力作用下深部软岩沿空巷道围岩变形量大,在空间上呈现出明显的区域性和非对称性的特征;基于巷道初步设计方案和围岩变形破坏特征,及时有效的调整支护方案,对巷道进行分段式、非对称、区域化综合治理,形成深部软岩巷道围岩控制长效机制,为同类型深部软岩巷道地压治理提供了理论和技术支撑。

Periodicity in Delta-modulated feedback control

The Delta-modulated feedback control of a linear system introduces nonlinearity into the system through switchings between two input values. It has been found that Delta-modulation gives rise to periodic orbits. The existence of periodic points of all orders of Sigma-Delta modulation with ＂leaky＂ integration is completely characterized by some interesting groups of polynomials with ＂sign＂ coefficients. The results are naturally generalized to Sigma-Delta modulations with multiple delays, Delta-modulations in the ＂downlink＂, unbalanced Delta-modulations and systems with two-level quantized feedback. Further extensions relate to the existence of periodic points arising from Delta-modulated feedback control of a stable linear system in an arbitrary direction, for which some necessary and sufficient conditions are given.

Satisfactory control of discrete-time linear periodic systems

In this paper satisfactory control for discrete-time linear periodic systems is studied. Based on a suitable time-invariant state sampled reformulation, periodic state feedback controller has been designed such that desired requirements of steady state covariance, H-infinity rejection bound and regional pole assignment for the periodic system are met simultaneously. By using satisfactory control theory, the problem of satisfactory periodic controller can be transformed into a linear programming problem subject to a set of linear matrix inequalities （LMIs）, and a feasible designing approach is presented via LMI technique. Numeric example validates the obtained conclusion.

Adaptive Iterative Learning Control for Nonlinear Time-delay Systems with Periodic Disturbances Using FSE-neural Network

An adaptive iterative learning control scheme is presented for a class of strict-feedback nonlinear time-delay systems, with unknown nonlinearly parameterised and time-varying disturbed functions of known periods. Radial basis function neural network and Fourier series expansion （FSE） are combined into a new function approximator to model each suitable disturbed function in systems. The requirement of the traditional iterative learning control algorithm on the nonlinear functions （such as global Lipschitz condition） is relaxed. Furthermore, by using appropriate Lyapunov-Krasovskii functionals, all signs in the closed loop system are guaranteed to be semiglobally uniformly ultimately bounded, and the output of the system is proved to converge to the desired trajectory. A simulation example is provided to illustrate the effectiveness of the control scheme.

Control of Beam Halo-Chaos for an Intense Charged-Particle Beam Propagating Through Double Periodic Focusing Field by Soliton

We study an intense beam propagating through the double periodic focusing channel by the particle-coremodel,and obtain the beam envelope equation.According to the Poincare-Lyapunov theorem,we analyze the stabilityof beam envelope equation and find the beam halo.The soliton control method for controlling the beam halo-chaos isput forward based on mechanism of halo formation and strategy of controlling beam halo-chaos,and we also prove thevalidity of the control method,and furthermore,the feasible experimental project is given.We perform multiparticlesimulation to control the halo by using the soliton controller.It is shown that our control method is effective.We alsofind the radial ion density changes when the ion beam is in the channel,not only the halo-chaos and its regeneration canbe eliminated by using the nonlinear control method,but also the density uniformity can be found at beam's centre aslong as an appropriate control method is chosen.

口服中药治疗慢性阻塞性肺疾病急性加重随机对照试验的文献特征及结局指标研究

背景口服中药在慢性阻塞性肺疾病急性加重(AECOPD)的治疗中应用广泛,但相关临床试验的结局指标尚未得到统一和规范。目的通过筛选已发表的以口服中药为AECOPD治疗措施的随机对照试验(RCT),总结其文献特征和选用的结局指标情况,为中医药治疗AECOPD临床试验设计和结局指标选择提供参考。方法计算机检索中国知网、万方数据知识服务平台、维普网、中国生物医学文献数据库、PubMed、Embase、Web of Science、Cochrane Library、ClinicalTrials.gov、中国临床试验注册中心,获取口服中药治疗AECOPD的RCT和临床试验注册方案,检索时限为2018年1月—2022年10月。由2位评价员独立筛选文献、提取资料后,采用定性分析的方法,对纳入研究的结局指标选择情况进行描述。结果纳入578篇文献,包含574篇已报告试验结果的RCT及4个临床试验注册方案。574篇RCT共纳入51508例患者。88篇文献在纳入标准中限定了患者的疾病分级,361篇文献在纳入标准中限定了中医证型,6篇文献报告了盲法,6篇文献提及了随访。纳入文献共涉及4030个结局指标,单篇文献结局指标数量范围为1~24个。按照结局指标的功能属性,将其归为8个指标域:中医症状/证候、症状/体征、理化检测、生活质量、远期预后、经济学评估、安全性评价、其他,报告率最高的指标域是理化检测,报告频次排名前5位的结局指标项目是:有效率(11.5%)、第1秒用力呼气容积(7.5%)、中医症状/证候评分(7.0%)、第1秒用力呼气容积/用力肺活量(6.8%)、用力肺活量(4.6%)。445篇文献报告了有效率的组成,报告率排名前5位的研究指标依次为症状(423篇)、体征(281篇)、中医证候评分(203篇)、实验室检查(89篇)、肺功能(71篇)。结论口服中药治疗AECOPD的RCT涉及的结局指标数量多、范围广,纳入的文献在不同程度上关注了口服中药对AECOPD患者的症状体征、理化检测指标、生活质量、远期预后、经济学评价和安全性结局等方面的影响。但结局指标的选择仍存在多方面的问题:结局指标主次不清;主要关注替代终点,对临床终点的关注不足;对卫生经济学指标关注不足;有效性参考来源不一、判断标准不一。研究者可参考已发表的核心指标集,合理设计结局指标,以提高中医药临床研究的质量。

时变时滞奇异复杂动态网络的间歇控制与同步

利用周期性间歇控制策略研究了具有时变时滞的奇异复杂动态网络的指数同步问题.通过构建Lyapunov-Krasovskii泛函,推导出驱动系统和响应系统的指数同步判据;然后运用LMI工具箱求解线性矩阵不等式,得出了控制增益矩阵.最后,利用Runge-Kutta算法求解具有时变时滞微分代数方程,并通过数值仿真验证了结论的有效性.

冬季不同最小通风量模式对肉种鸡育雏育成期生长性能及环控能耗的影响

为研究冬季不同最小通风量模式对肉种鸡育雏育成期舍内环境、生长性能以及环控能耗的影响,试验测试了间歇式通风和连续式通风两种不同的最小通风量通风控制模式,分别比较了两种模式下鸡舍内主要环境质量参数、环控能耗、体重均匀度和抗体效价。结果显示:第一周,连续通风温度高于间歇通风(P>0.05),相对湿度显著低于间歇通风(P<0.05),二氧化碳浓度显著高于间歇通风模式(P<0.05),第2~10周,连续通风温度极显著高于间歇通风(P<0.01),相对湿度极显著低于间歇通风(P<0.01),二氧化碳浓度极显著高于间歇通风模式(P<0.01),同时连续通风鸡舍内环境参数波动度小于间歇通风;试验期间连续通风环控总能耗(7036.01 kW·h)低于间歇通风(7633.02 kW·h),并且连续通风种鸡体重均匀度优于间歇通风;H5N1亚型禽流感病毒抗体效价显著高于间歇通风(P<0.05),H7N9亚型禽流感病毒抗体效价极显著高于间歇通风(P<0.01)。研究表明,冬季肉种鸡育雏育成期采用连续通风的最小通风量模式对比间歇通风的最小通风量模式,可以获得更加稳定的舍内环境,雏鸡生长性能以及免疫效果更优,且能源消耗更少。

基于周期性最大功率点检测的风电机组功率备用控制方法

风电机组通常运行于最大功率输出模式,无法为受扰电网提供紧急功率支撑。稳态时预留部分出力可提高风电机组主动电网支撑能力,为此提出一种基于周期性最大功率点(MPP)检测的风电机组功率备用控制(PRC)方法。通过周期性执行最大功率点跟踪程序检测风电机组实时MPP,一旦检测到MPP即可确定PRC模式参考值并切换为直接功率控制。设置伪单调转速-机械功率曲线使风电机组稳定运行在超速功率备用点,并通过储能装置平抑MPP检测产生的峰值功率波动。仿真结果表明提出的控制方法在定风速和变风速情况下均可以准确控制检测风电机组MPP并实现PRC,并且使得风电机组一次调频效果优于传统PRC。