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Fluid damping clearance in a control valve of injector

ZHANG Jianming, ZHANG Weigang, YANG Bing, WANG Yawei

《机械工程前沿（英文）》 2007年 第2卷 第4期   页码 439-441 doi: 10.1007/s11465-007-0075-x

摘要： A force model of a control valve of injector is set up, and the changes of the fluid damping clearance are investigated on the basis of the results of the computational fluid dynamics (CFD) and the experiments of control valve of injector. Results indicate that a damping clearance of 0.02–0.03 mm between the poppet and the valve guide is the most sufficient to dampen any excessive control valve poppet bouncing.

关键词： control     computational     bouncing     CFD     excessive control    

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Analysis of load transfer stability control strategy in hydraulic synchronized continuous slippage

LIU Yan-bo, WU Jian-zhong, ZHANG Xuan

《机械工程前沿（英文）》 2006年 第1卷 第2期   页码 222-226 doi: 10.1007/s11465-006-0007-1

摘要： Hydraulic synchronized continuous slippage technique, which integrates mechanical, electrical and hydraulic control, is introduced in this paper for the practical requirements of some construction projects. The core of this technique (the stability of the load transfer) is illustrated in detail. Three speed control strategies to transfer the load excessive, lower and same speed are presented to accomplish the smoothness and stability in the process of slippage. An optimization of the speed control strategy (same speed) is deduced from the modeling analysis and its validity and maneuverability are tested by practical application, which provides evidence for similar engineering in theory and practice.

关键词： excessive     slippage technique     optimization     continuous slippage     engineering    

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Control concept and countermeasures for shallow lakes' eutrophication in China

JIN Xiangcan, LU Shaoyong, HU Xiaozhen, JIANG Xia, WU Fengchang

《环境科学与工程前沿（英文）》 2008年 第2卷 第3期   页码 257-266 doi: 10.1007/s11783-008-0063-3

摘要： Research on lake eutrophication in China began in the early 1970s, and many lakes in China are now known to be in meso-eutrophic status. Lake eutrophication has been showing a rapidly increasing trend since 2000. Investigations show that the main reasons for lake eutrophication include a fragile lake background environment, excessive nutrient loading into lakes, excessive human activities, ecological degeneration, weak environmental protection awareness, and lax lake management. Major mechanisms resulting from lake eutrophication include nutrient recycling imbalance, major changes in water chemistry (pH, oxygen, and carbon), lake ecosystem imbalance, and algal prevalence in lakes. Some concepts for controlling eutrophication should be persistently proposed, including lake catchment control, combination of pollutant source control with ecological restoration, protection of three important aspects (terrestrial ecology, lake coast zone, and submerged plant), and combination of lake management with regulation. Measures to control lake eutrophication should include pollution source control (i.e., optimize industrial structural adjustments in the lake catchment, reduce nitrogen and phosphorus emission amounts, and control endogenous pollution) and lake ecological restoration (i.e. establish a zone-lake buffer region and lakeside zone, protect regional vegetation, utilize hydrophytes in renovation technology); countermeasures for lake management should include implementing water quality management, identifying environmental and lake water goals, legislating and formulating laws and regulations to protect lakes, strengthening publicity and the education of people, increasing public awareness through participation in systems and mechanic innovations, establishing lake region management institutions, and ensuring implementation of governance and management measures.

关键词： excessive     participation     prevalence     lakeside     Research    

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Short-term effects of excessive anaerobic reaction time on anaerobic metabolism of denitrifying polyphosphate

Gang GUO, Yayi WANG, Chong WANG, Hong WANG, Mianli PAN, Shaowei CHEN

《环境科学与工程前沿（英文）》 2013年 第7卷 第4期   页码 616-624 doi: 10.1007/s11783-013-0505-4

摘要： The short-term effect of anaerobic reaction time (AnRT) (i.e., 90, 120 and 150 min) on the denitrifying phosphorus (P) removal performance and N O production was examined using a denitrifying enhanced biologic phosphorus removal (EBPR) sludge acclimatized with mixed acetate (HAc) and propionate (Pro) (in the molar ratio 3∶1) as carbon sources. The results showed that when the AnRT was prolonged from 90 to 150 min, the anaerobic polyhydroxyalkanoate (PHA) synthesis was decreased by 15.3%. Moreover, the ineffective PHA consumption occurred in anaerobic phases and contributed to an increased accumulation and higher free nitrous acid (FNA) concentrations (≥0.001–0.0011 mg HNO -N/L) in the subsequent anoxic phases, causing a severe inhibition on anoxic P-uptake and denitrification. Accordingly, the total nitrogen (TN) and total phosphorus (TP) removal efficiencies dropped by approximately 6.3% and 85.5%, respectively; and the ratio of anoxic N O-N production to TN removal increased by approximately 3.8%. The fluorescence in situ hybridization (FISH) analysis revealed that the sludge was mainly dominated by (62.0% (SE = 1.5%)). In conclusion, the short-term excessive anaerobic reaction time negatively impacted denitrifying P removal performance and stimulated more N O production, and its effect on P removal was more obvious than that on nitrogen removal.

关键词： Denitrifying phosphorus removal     anaerobic reaction time     nitrous oxide     polyhydroxyalkanoate     free nitrous acid     fluorescence in-situ hybridization    

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Effects of EGR on combustion process of DI diesel engine during cold start

PENG Haiyong, CUI Yi, SHI Lei, DENG Kangyao

《能源前沿（英文）》 2008年 第2卷 第2期   页码 202-210 doi: 10.1007/s11708-008-0038-x

摘要： Experiments on the effects of external and internal exhaust gas recirculation (EGR) on combustion and emission performance during a cold start process were investigated in a 135 single-cylinder DI diesel engine. Combustion was improved during the initial ignition cycles by introducing internal or external EGR. The addition of an appropriate amount of internal or external EGR can promote the combustion stability significantly. However, excessive amounts of external EGR could lead to extremely unstable combustion or even misfiring. An appropriate amount of internal or external EGR decreased smoke opacity effectively during a cold start. External EGR reduced NO emissions effectively while internal EGR led to an increase in NO emissions due to thermal effects.

关键词： opacity     combustion     excessive     NO     process    

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基于修正模拟退火算法及溢出面积模型的固定边界布图规划 Article

De-xuan ZOU,Gai-ge WANG,Gai PAN,Hong-wei QI

《信息与电子工程前沿（英文）》 2016年 第17卷 第11期   页码 1228-1244 doi: 10.1631/FITEE.1500386

摘要： 无边界布图规划研究面积及线长减少问题很难满足现代设计需求，因此通常被认为是无意义的。我们关注一种难度更大且更有意义的问题--固定边界布图规划。该问题将固定边界约束条件加入无边界布图规划中，使其在实体设计中更有趣、更具挑战性。本文的工作主要分为两部分。第一，提出了一种修正模拟退火算法（Modified simulated annealing algorithm, MSA）。在进化过程初期，用一种新的衰减方程来缓慢减小温度，以增强MSA的全局搜索能力。然后，用传统衰减方程来快速减小温度，以维持MSA的局部搜索能力。第二，设计了一种溢出面积模型来引导MSA寻找可行解，为精炼可行解节省了大量时间。另外，B*-tree是一种有效的布图规划表示法，它被用来执行MSA的扰动操作。最后，以六组带有不同空置率及高宽比的benchmark为例，证实本文所提方法在解决固定边界布图规划问题上的效率，这些问题包括电路n10，n30，n50，n100，n200和n300。与几种现有方法相比，本方法能够更有效地获得令人满意的目标函数值，它们与芯片面积、线长和固定边界约束有关。

关键词： 固定边界布图规划；修正的模拟退火算法；全局搜索；溢出面积模型；B*-tree表示法    

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Effects of MgO promoter on properties of Ni/Al2O3 catalysts for partial oxidation of methane to syngas

QIU Yejun, CHEN Jixiang, ZHANG Jiyan

《化学科学与工程前沿（英文）》 2007年 第1卷 第2期   页码 167-171 doi: 10.1007/s11705-007-0031-7

摘要： The effects of MgO promoter on the physico-chemical properties and catalytic performance of Ni/AlO catalysts for the partial oxidation of methane to syngas were studied by means of BET, XRD, H-TPR, TEM and performance evaluation. It was found that the MgO promoter benefited from the uniformity of nickel species in the catalysts, inhibited the formation of NiAlO spinel and improved the interaction between nickel species and support. These results were related to the formation of NiO MgO solid solution and MgAlO spinel. Moreover, for the catalysts with a proper amount of MgO promoter, the nickel dispersiveness was enhanced, therefore making their catalytic performance in methane partial oxidation improved. However, the excessive MgO promoter exerted a negative effect on the catalytic performance. Meanwhile, the basicity of MgO promoted the reversed water gas shift reaction, which led to an increase in CO selectivity and a decrease in H2 selectivity. The suitable content of MgO promoter in Ni/AlO catalyst was ?7 wt-%.

关键词： excessive     selectivity     decrease     dispersiveness     physico-chemical    

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钢产量增长机制的解析及2000—2007年我国钢产量增长过快原因的探索

陆钟武,岳强

《中国工程科学》 2010年 第12卷 第6期   页码 4-11

摘要：

分两步解析钢产量的增长机制，首先在若干假设条件下提出了钢产量增长的基准模式，其主要特点是钢产量与GDP同步增长，分析了基准模式下的钢产量、在役钢量、GDP以及它们的年增长率；然后讨论偏离基准模式的各种可能性，及其对钢产量增速的影响。在此基础上得到了钢产量年增长率的基本计算式。分析了偏离基准模式对单位GDP钢产量的影响。在对钢产量增长机制进行解析的基础上，广泛联系全社会发生的各种现象，提出使我国钢产量增速远远超过GDP增速的16种现象，提出在宏观调控工作中，要区别对待这些现象。从中、日、美三国单位GDP钢产量数据对比可见，我国降低单位GDP钢产量的空间很大。文章为我国钢铁行业的宏观调控提供了新思路。

关键词： 钢产量     在役钢量     GDP     年增长率     机制     基准模式    

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WHEAT STRIPE RUST AND INTEGRATION OF SUSTAINABLE CONTROL STRATEGIES IN CHINA

《农业科学与工程前沿（英文）》 2022年 第9卷 第1期   页码 37-51 doi: 10.15302/J-FASE-2021405

摘要：

Stripe (yellow) rust caused by Puccinia striiformis f. sp. tritici occurs in almost all wheat-producing regions of the world. Severe countrywide epidemics in China have caused substantial yield losses. Growing resistant cultivars is the best strategy to control this disease but the pathogen can overcome resistance in wheat cultivars. The high variation in the virulence of the pathogen combined with the large areas of susceptible wheat cultivars enables the pathogen population to increase rapidly and disperse over long distances under favorable environmental conditions, resulting in severe pandemics within cropping seasons. Current stripe rust control measures are based on many years of research including the underlying epidemiology regarding year-to-year survival of the pathogen, pathways of pathogen dispersal within seasons and years, the role of P. striiformis sexual hybridization, the use of resistance sources in breeding programs, and year-round surveillance of national wheat crops that are present in different parts of the country throughout the year. All these strategies depend on accurate prediction of epidemics, more precise use of fungicides to meet national requirements and better deployment of resistance genes. New ideas with potential application in sustainable protection of stripe rust include negative regulatory gene editing, resistance gene overexpression and biological control based on microbiomes.

 

关键词： sustainable disease control / integrated control Puccinia striiformis / Triticum aestivum    

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A systematic review of current and emergent manipulator control approaches

Syed Ali AJWAD,Jamshed IQBAL,Muhammad Imran ULLAH,Adeel MEHMOOD

《机械工程前沿（英文）》 2015年 第10卷 第2期   页码 198-210 doi: 10.1007/s11465-015-0335-0

摘要：

Pressing demands of productivity and accuracy in today’s robotic applications have highlighted an urge to replace classical control strategies with their modern control counterparts. This recent trend is further justified by the fact that the robotic manipulators have complex nonlinear dynamic structure with uncertain parameters. Highlighting the authors’ research achievements in the domain of manipulator design and control, this paper presents a systematic and comprehensive review of the state-of-the-art control techniques that find enormous potential in controlling manipulators to execute cutting-edge applications. In particular, three kinds of strategies, i.e., intelligent proportional-integral-derivative (PID) scheme, robust control and adaptation based approaches, are reviewed. Future trend in the subject area is commented. Open-source simulators to facilitate controller design are also tabulated. With a comprehensive list of references, it is anticipated that the review will act as a first-hand reference for researchers, engineers and industrial-interns to realize the control laws for multi-degree of freedom (DOF) manipulators.

关键词： robot control     robust and nonlinear control     adaptive control     intelligent control     industrial manipulators     robotic arm    

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Emerging contaminant control: From science to action

《环境科学与工程前沿（英文）》 2022年 第16卷 第6期 doi: 10.1007/s11783-022-1559-y

摘要： Since the concept of emerging contaminants (ECs) was first proposed in 2001, the global scientific research of ECs has developed rapidly. In the past decades, great progress has been achieved in the scientific research of ECs in China, including the establishment of EC analysis method system, the evaluation of the pollution status, pollution characteristics and environmental risk of ECs in typical regions of China, and establishment of EC control technology system. Continuous progress in scientific research of ECs promoted China’s action on EC control. It is planned that the environmental risk of ECs will be generally controlled by 2035 in China. Priority ECs should be screened for environmental management. Although great efforts have been made, the EC control in China still faces tremendous challenges. It is necessary to bridge the gap between scientific research and decision-making management. Based on the science and technology study, various measures such as engineering, policy management and public participation should be combinedly adopted for EC control.

关键词： Emerging contaminants     Priority pollutants     PPCPs     POPs     Control policy    

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An integrated approach for machine-learning-based system identification of dynamical systems under control: application towards the model predictive control of a highly nonlinear reactor system

《化学科学与工程前沿（英文）》 2022年 第16卷 第2期   页码 237-250 doi: 10.1007/s11705-021-2058-6

摘要： Advanced model-based control strategies, e.g., model predictive control, can offer superior control of key process variables for multiple-input multiple-output systems. The quality of the system model is critical to controller performance and should adequately describe the process dynamics across its operating range while remaining amenable to fast optimization. This work articulates an integrated system identification procedure for deriving black-box nonlinear continuous-time multiple-input multiple-output system models for nonlinear model predictive control. To showcase this approach, five candidate models for polynomial and interaction features of both output and manipulated variables were trained on simulated data and integrated into a nonlinear model predictive controller for a highly nonlinear continuous stirred tank reactor system. This procedure successfully identified system models that enabled effective control in both servo and regulator problems across wider operating ranges. These controllers also had reasonable per-iteration times of ca. 0.1 s. This demonstration of how such system models could be identified for nonlinear model predictive control without prior knowledge of system dynamics opens further possibilities for direct data-driven methodologies for model-based control which, in the face of process uncertainties or modelling limitations, allow rapid and stable control over wider operating ranges.

关键词： nonlinear model predictive control     black-box modeling     continuous-time system identification     machine learning     industrial applications of process control    

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Precision control system of two-DOF stage with linear ultrasonic motor

ZHANG Hanlei, SHI Yunlai, ZHAO Chunsheng

《机械工程前沿（英文）》 2008年 第3卷 第4期   页码 421-425 doi: 10.1007/s11465-008-0063-9

摘要： Using an appropriate control method, linear ultrasonic motors can be used in applications requiring high position accuracy. In this paper, a closed loop PI control system is designed to achieve high position accuracy during the control of a two-DOF stage driven by linear ultrasonic motors. Two ultrasonic motors are mounted on the stage to generate motion in two orthogonal directions. The PI control algorithm is used to increase the stability and accuracy of position control. The -axis mover covers 30 mm forward and backward in less than 0.3 s settling time and the -axis mover in less than 0.4 s. Experimental results denote that the control strategy proposed in this paper appears to have high efficiency, quick response, and high accuracy.

关键词： settling     position accuracy     PI control     control algorithm     orthogonal    

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A hybrid LQR-PID control design for seismic control of buildings equipped with ATMD

Amir Hossein HEIDARI, Sadegh ETEDALI, Mohamad Reza JAVAHERI-TAFTI

《结构与土木工程前沿（英文）》 2018年 第12卷 第1期   页码 44-57 doi: 10.1007/s11709-016-0382-6

摘要： This paper presents an efficient hybrid control approach through combining the idea of proportional-integral-derivative (PID) controller and linear quadratic regulator (LQR) control algorithm. The proposed LQR-PID controller, while having the advantage of the classical PID controller, is easy to implement in seismic-excited structures. Using an optimization procedure based on a cuckoo search (CS) algorithm, the LQR-PID controller is designed for a seismic- excited structure equipped with an active tuned mass damper (ATMD). Considering four earthquakes, the performance of the proposed LQR-PID controller is evaluated. Then, the results are compared with those given by a LQR controller. The simulation results indicate that the LQR-PID performs better than the LQR controller in reduction of seismic responses of the structure in the terms of displacement and acceleration of stories of the structure.

关键词： seismic control     tuned mass dampers     cuckoo search     PID controller     LQR controller    

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Analysis and stabilization control of a voltage source controlled wind farm under weak grid conditions

《能源前沿（英文）》 2022年 第16卷 第6期   页码 943-955 doi: 10.1007/s11708-021-0793-5

摘要： This paper investigates and discusses the interaction stability issues of a wind farm with weak grid connections, where the wind turbines (WTs) are controlled by a new type of converter control strategy referred to as the voltage source (VS) control. The primary intention of the VS control method is to achieve the high-quality inertial response capability of a single WT. However, when it is applied to multiple WTs within a wind farm, its weak-grid performance regarding the stability remains concealed and needs to be clarified. To this end, a frequency domain model of the wind farm under the VS control is first developed. Based on this model and the application of a stability margin quantification index, not only the interactions between the wind farm and the weak grid but also those among WTs will be systematically assessed in this paper. A crucial finding is that the inertial response of VS control has negative impacts on the stability margin of the system, and the dominant instability mode is more related to the interactions among the WTs rather than the typical grid-wind farm interaction. Based on this knowledge, a stabilization control strategy is then proposed, aiming for stability improvements of VS control while fulfilling the demand of inertial responses. Finally, all the results are verified by time-domain simulations in power systems computer aided design/electromagnetic transients including DC(PSCAD/EMTDC).

关键词： weak grids     voltage source (VS) control     wind turbine (WT)     stabilization control     wind farm     inertial response    

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标题 作者 时间 类型 操作

Fluid damping clearance in a control valve of injector

ZHANG Jianming, ZHANG Weigang, YANG Bing, WANG Yawei

期刊论文

Analysis of load transfer stability control strategy in hydraulic synchronized continuous slippage

LIU Yan-bo, WU Jian-zhong, ZHANG Xuan

期刊论文

Control concept and countermeasures for shallow lakes' eutrophication in China

JIN Xiangcan, LU Shaoyong, HU Xiaozhen, JIANG Xia, WU Fengchang

期刊论文

Short-term effects of excessive anaerobic reaction time on anaerobic metabolism of denitrifying polyphosphate

Gang GUO, Yayi WANG, Chong WANG, Hong WANG, Mianli PAN, Shaowei CHEN

期刊论文

Effects of EGR on combustion process of DI diesel engine during cold start

PENG Haiyong, CUI Yi, SHI Lei, DENG Kangyao

期刊论文

基于修正模拟退火算法及溢出面积模型的固定边界布图规划

De-xuan ZOU,Gai-ge WANG,Gai PAN,Hong-wei QI

期刊论文

Effects of MgO promoter on properties of Ni/Al2O3 catalysts for partial oxidation of methane to syngas

QIU Yejun, CHEN Jixiang, ZHANG Jiyan

期刊论文

钢产量增长机制的解析及2000—2007年我国钢产量增长过快原因的探索

陆钟武,岳强

期刊论文

WHEAT STRIPE RUST AND INTEGRATION OF SUSTAINABLE CONTROL STRATEGIES IN CHINA

期刊论文

A systematic review of current and emergent manipulator control approaches

Syed Ali AJWAD,Jamshed IQBAL,Muhammad Imran ULLAH,Adeel MEHMOOD

期刊论文

Emerging contaminant control: From science to action

期刊论文

An integrated approach for machine-learning-based system identification of dynamical systems under control: application towards the model predictive control of a highly nonlinear reactor system

期刊论文

Precision control system of two-DOF stage with linear ultrasonic motor

ZHANG Hanlei, SHI Yunlai, ZHAO Chunsheng

期刊论文

A hybrid LQR-PID control design for seismic control of buildings equipped with ATMD

Amir Hossein HEIDARI, Sadegh ETEDALI, Mohamad Reza JAVAHERI-TAFTI

期刊论文

Analysis and stabilization control of a voltage source controlled wind farm under weak grid conditions

期刊论文