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.

MINIMUM PERIOD CONTROL PROBLEM FOR INFINITE DIMENSIONAL SYSTEM

In order to solve the so-called minimum period control problem for a class of abstract evolutionary systems, the authors study an infinite dimensional time optimal control problem with mixed type target set. To the latter problem complete results are established, which then are applied to the former to derive the desirable answer.

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.

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.

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.

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。

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。

Periodic Solutions of a Cooperative System with State Feedback Control

In this paper, we propose a semi-continuous dynamical system to study the cooperative system with feedback control. Based on geometrical analysis and the analogue of Poincare criterion, the existence and stability of the positive order one periodic solutions are given. Numerical results are carried out to illustrate the feasibility of our main results.

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.

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.

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.

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。

艾司洛尔围术期应用热点与趋势文献计量学分析

目的探讨艾司洛尔在围术期应用的热点及研究趋势。方法检索Web of Science(WOS)数据库自建库起至2023年5月23日的相关文献,采用Citespace 5.8.R3软件,对涉及的国家/地区发文及合作情况,关键词共现、突现、聚类情况及文献共被引情况进行可视化分析。结果共获得有效文献422篇。研究始于1993年,呈波动上升趋势,2013年最多(24篇)。共涉及42个国家/地区,发文量排名前3的为美国(101篇)、日本(55篇)、中国(37篇);美国与其他国家合作最紧密,但多数国家/地区间的合作较少。共198种期刊发表了该领域的文章,Anesthesia and Analgesia(28篇)、Journal of Clinical Anesthesia(17篇)、Canadian Journal of Anesthesia-Journal Canadien D Anesthesie(14篇)是该领域研究发文量较高的3个期刊(期刊引证报告中均位列Q1区)。出现频次较高的关键词有“anes⁃thesia”(89次)、“surgery”(73次)、“remifentanil”(49次)、“propofol”(44次)、“sodium nitroprusside”(31次)、“cardiac surgery”(30次)等;共获得16个突现词,“lidocaine”为2018年至2023年突现度较高(3.67)的关键词;共有19个重要的聚类标签,主要集中于艾司洛尔药理作用及手术、艾司洛尔对比用药、联合使用麻醉剂等方面研究。文献总被引频次7885次,共被引文献的概括性主题包括non-cardiac surgery、eamolot pretreatment等。结论艾司洛尔围术期应用主要集中在心脏手术、心肺旁路手术等,艾司洛尔在非心脏手术中的应用、血流动力学响应、对麻醉药物作用的影响等是目前研究的热点。

植物不同生长期成分含量变化研究

综述了植物不同生长期多酚、多糖、氨基酸和蛋白质、萜类和挥发性成分含量变化的研究现状,为药材质量评价、确定最佳采收期、合理施肥、果蔬质量控制、副产物的合理开发利用等提供理论依据。

快速刀具伺服系统位置域重复控制设计及其数字实现

在非圆零件车削过程中,快速刀具伺服(Fast tool servo,FTS)的运动精度直接影响零件的加工质量.主轴变速加工使得FTS的参考目标信号周期时变而不确定,这对实现其渐近跟踪提出了极大的挑战.本文利用FTS的位置域周期特性,提出一种基于位置域重复控制和时域速度反馈镇定的FTS系统复合控制设计方法,并给出位置域改进型重复控制器(Spatial modified repetitive controller,SMRC)的数字实现算法,实现对时变周期参考目标信号的高精度跟踪.首先,建立包含位置相关时变周期参考目标信号内模的SMRC,并引入位置域相位超前装置对镇定补偿器引起的相位滞后进行补偿,在此基础上构建复合控制律.然后应用小增益定理和算子理论,推导出控制系统的稳定性条件,在保持系统采样频率不变的条件下,应用插值法建立SMRC的数字实现算法,确保位置域重复控制和时域镇定控制器的同步执行.最后,通过仿真验证所设计的FTS控制系统具有满意的时变周期跟踪性能和鲁棒性,并通过与其他位置域重复控制方法的比较,说明所提方法同时具有更好的暂态和稳态性能.

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。

抗战时期大后方水泥工业统制措施及其影响——以四川水泥公司为中心的分析

中日全面战争爆发后,为了准备长期抗战,国民政府经济部工矿调整处设立水泥管理委员会作为统制大后方水泥的核心机构,对水泥工业施行了严格的统制,以保障军事民用的需要。战时水泥工业统制涉及企业近十家,其中尤以四川水泥公司最具典型性和代表性。水泥管理委员会通过配发准购证及核定销售价格等方式,全面控制了四川水泥公司产品生产和分配。战时水泥统制的施行一方面有利于保障战时军事物资供应,为抗战的胜利做出了巨大的贡献;另一方面,在严密的统制经济管控之下,四川水泥公司丧失了自主定价和自由经营权力,从而导致经营效益日趋下滑,对企业发展产生了诸多方面的负面影响。

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。