Rh(III)‐catalyzed C–H activation of N‐protected anilines and chemo‐divergent couplings with acroleins/enones have been realized for synthesis of three classes of heterocycles.The oxidative coupling of N‐pyridylan...Rh(III)‐catalyzed C–H activation of N‐protected anilines and chemo‐divergent couplings with acroleins/enones have been realized for synthesis of three classes of heterocycles.The oxidative coupling of N‐pyridylaniline afforded dihydroquinolones with the acrolein being a major hydrogen acceptor.When the directing group was replaced by pyrimidyl in the same system,redox‐neutral coupling occurred to afford hemiaminal ethers.Oxidative annulation of N‐pyridylanilines with enones using AgBF4 oxidant afforded atropisomeric quinolinium salts.展开更多
This paper proposes an event-triggered stochastic model predictive control for discrete-time linear time-invariant(LTI)systems under additive stochastic disturbances.It first constructs a probabilistic invariant set a...This paper proposes an event-triggered stochastic model predictive control for discrete-time linear time-invariant(LTI)systems under additive stochastic disturbances.It first constructs a probabilistic invariant set and a probabilistic reachable set based on the priori knowledge of system uncertainties.Assisted with enhanced robust tubes,the chance constraints are then formulated into a deterministic form.To alleviate the online computational burden,a novel event-triggered stochastic model predictive control is developed,where the triggering condition is designed based on the past and future optimal trajectory tracking errors in order to achieve a good trade-off between system resource utilization and control performance.Two triggering parametersσandγare used to adjust the frequency of solving the optimization problem.The probabilistic feasibility and stability of the system under the event-triggered mechanism are also examined.Finally,numerical studies on the control of a heating,ventilation,and air conditioning(HVAC)system confirm the efficacy of the proposed control.展开更多
The new Austrian tunneling method （NATM） is widely applied in design and construction of underground engineering projects. When the type and distribution of unfavorable geological bodies （UGBs） associated with the...The new Austrian tunneling method （NATM） is widely applied in design and construction of underground engineering projects. When the type and distribution of unfavorable geological bodies （UGBs） associated with their influences on geoengineering are complicated or unfortunately are overlooked, we should pay more attentions to internal features of rocks grades IV and V （even in local but mostly controlling zones）. With increasing attentions to the characteristics, mechanism and influences of engineering construction-triggered geohazards, it is crucial to fully understand the disturbance of these geohazards on project construction. A reasonable determination method in construction procedure, i.e. the shape of working face, the type of engineering support and the choice of feasible procedure, should be considered in order to mitigate the construction-triggered geohazards. Due to their high sensitivity to groundwater and in-situ stress, various UGBs exhibit hysteretic nature and failure modes. To give a complete understanding on the internal causes, the emphasis on advanced comprehensive geological forecasting and overall reinforcement treatment is therefore of more practical significance. Compre- hensive evaluation of influential factors, identification of UGB, and measures of discontinuity dynamic controlling comprises the geoengineering condition evaluation and dynamic controlling method. In a case of a cut slope, the variations of UGBs and the impacts of key environmental factors are presented, where more severe construction-triggered geohazards emerged in construction stage than those predicted in design and field investigation stages. As a result, the weight ratios of different influential factors with respect to field investigation, design and construction are obtained.展开更多
A novel variable displacement compressor (VDC) for automotive air conditioner (AAC) is introduced, which inherits the advantages of common wobble plate type VDC. It has fewer parts and makes less noise, and instead of...A novel variable displacement compressor (VDC) for automotive air conditioner (AAC) is introduced, which inherits the advantages of common wobble plate type VDC. It has fewer parts and makes less noise, and instead of pneumatic valve the displacement is controlled by electronic control valve. In order to know the control mechanism well and get a good control effect, a mathematical model for the variable displacement mechanism is developed according to the geometrical and kinematical information of the compressor. Using the model, the effect of relevant parameters on variable displace control is estimated. It is helpful to make the optimum decision in the flow control of AAC. As the novel displacement control device, the structure and control rule of electronic control valve is introduced. It can get better effect than the conventional pneumatic valves. And by using this new electronic control device, the optimum systemic control of AAC is available.展开更多
针对风冷精密空调在多点环境变化下响应滞后与能耗偏高问题,设计了一种基于物联网通信的风冷精密空调节能控制系统。系统构建“感知-传输-控制”3层架构,融合远距离无线电(Long Range Radio,LoRa)或消息队列遥测传输(Message Queuing Te...针对风冷精密空调在多点环境变化下响应滞后与能耗偏高问题,设计了一种基于物联网通信的风冷精密空调节能控制系统。系统构建“感知-传输-控制”3层架构,融合远距离无线电(Long Range Radio,LoRa)或消息队列遥测传输(Message Queuing Telemetry Transport,MQTT)协议实现温湿度数据的低功耗远程采集,通过边缘控制器与链路调度机制进行数据处理与任务分发,引入人工智能(Artificial Intelligence,AI)预测模型与比例-积分-微分(Proportional Integral Derivative,PID)融合策略实现自适应节能调控。实验验证表明,该系统在通信稳定性、调控响应速度与节能效率方面均优于传统控制方式,具备良好的工程适应性与推广价值。展开更多
为提升综合电能质量调节器(unified power quality conditioner,UPQC)在不同工况下串联侧抗扰动性能,提出一种在abc坐标系下基于电压、电流前馈的复合控制,对传统电网电压前馈进行改进并引入负载电流前馈,以进一步提升控制器动、静态性...为提升综合电能质量调节器(unified power quality conditioner,UPQC)在不同工况下串联侧抗扰动性能,提出一种在abc坐标系下基于电压、电流前馈的复合控制,对传统电网电压前馈进行改进并引入负载电流前馈,以进一步提升控制器动、静态性能。首先,根据UPQC拓扑结构建立串联侧单相数学模型以分析扰动对系统影响;其次,依据数学模型提出改进的复合前馈控制策略;最后,通过实物试验,分别从不同工况验证了该控制策略在UPQC系统中的有效性及优越性。展开更多
基金supported by the National Nature Science Foundation of China(21525208,21472186)the fund for new technology of methanol conversion of Dalian Institute of Chemical Physics(Chinese Academy of Sciences)~~
文摘Rh(III)‐catalyzed C–H activation of N‐protected anilines and chemo‐divergent couplings with acroleins/enones have been realized for synthesis of three classes of heterocycles.The oxidative coupling of N‐pyridylaniline afforded dihydroquinolones with the acrolein being a major hydrogen acceptor.When the directing group was replaced by pyrimidyl in the same system,redox‐neutral coupling occurred to afford hemiaminal ethers.Oxidative annulation of N‐pyridylanilines with enones using AgBF4 oxidant afforded atropisomeric quinolinium salts.
基金supported by the National Nature Science Foundation of China(62073194)the Natural Science Foundation of Shandong Province of China(ZR2023MF028)the Taishan Scholars Program of Shandong Province(tsqn202312008)
文摘This paper proposes an event-triggered stochastic model predictive control for discrete-time linear time-invariant(LTI)systems under additive stochastic disturbances.It first constructs a probabilistic invariant set and a probabilistic reachable set based on the priori knowledge of system uncertainties.Assisted with enhanced robust tubes,the chance constraints are then formulated into a deterministic form.To alleviate the online computational burden,a novel event-triggered stochastic model predictive control is developed,where the triggering condition is designed based on the past and future optimal trajectory tracking errors in order to achieve a good trade-off between system resource utilization and control performance.Two triggering parametersσandγare used to adjust the frequency of solving the optimization problem.The probabilistic feasibility and stability of the system under the event-triggered mechanism are also examined.Finally,numerical studies on the control of a heating,ventilation,and air conditioning(HVAC)system confirm the efficacy of the proposed control.
基金support by the National Natural Science Foundation of China (No. 41372324)support from the Chinese Special Funds for Major State Basic Research Project under Grant No. 2010CB732001
文摘The new Austrian tunneling method （NATM） is widely applied in design and construction of underground engineering projects. When the type and distribution of unfavorable geological bodies （UGBs） associated with their influences on geoengineering are complicated or unfortunately are overlooked, we should pay more attentions to internal features of rocks grades IV and V （even in local but mostly controlling zones）. With increasing attentions to the characteristics, mechanism and influences of engineering construction-triggered geohazards, it is crucial to fully understand the disturbance of these geohazards on project construction. A reasonable determination method in construction procedure, i.e. the shape of working face, the type of engineering support and the choice of feasible procedure, should be considered in order to mitigate the construction-triggered geohazards. Due to their high sensitivity to groundwater and in-situ stress, various UGBs exhibit hysteretic nature and failure modes. To give a complete understanding on the internal causes, the emphasis on advanced comprehensive geological forecasting and overall reinforcement treatment is therefore of more practical significance. Compre- hensive evaluation of influential factors, identification of UGB, and measures of discontinuity dynamic controlling comprises the geoengineering condition evaluation and dynamic controlling method. In a case of a cut slope, the variations of UGBs and the impacts of key environmental factors are presented, where more severe construction-triggered geohazards emerged in construction stage than those predicted in design and field investigation stages. As a result, the weight ratios of different influential factors with respect to field investigation, design and construction are obtained.
文摘A novel variable displacement compressor (VDC) for automotive air conditioner (AAC) is introduced, which inherits the advantages of common wobble plate type VDC. It has fewer parts and makes less noise, and instead of pneumatic valve the displacement is controlled by electronic control valve. In order to know the control mechanism well and get a good control effect, a mathematical model for the variable displacement mechanism is developed according to the geometrical and kinematical information of the compressor. Using the model, the effect of relevant parameters on variable displace control is estimated. It is helpful to make the optimum decision in the flow control of AAC. As the novel displacement control device, the structure and control rule of electronic control valve is introduced. It can get better effect than the conventional pneumatic valves. And by using this new electronic control device, the optimum systemic control of AAC is available.
文摘针对风冷精密空调在多点环境变化下响应滞后与能耗偏高问题,设计了一种基于物联网通信的风冷精密空调节能控制系统。系统构建“感知-传输-控制”3层架构,融合远距离无线电(Long Range Radio,LoRa)或消息队列遥测传输(Message Queuing Telemetry Transport,MQTT)协议实现温湿度数据的低功耗远程采集,通过边缘控制器与链路调度机制进行数据处理与任务分发,引入人工智能(Artificial Intelligence,AI)预测模型与比例-积分-微分(Proportional Integral Derivative,PID)融合策略实现自适应节能调控。实验验证表明,该系统在通信稳定性、调控响应速度与节能效率方面均优于传统控制方式,具备良好的工程适应性与推广价值。
文摘为提升综合电能质量调节器(unified power quality conditioner,UPQC)在不同工况下串联侧抗扰动性能,提出一种在abc坐标系下基于电压、电流前馈的复合控制,对传统电网电压前馈进行改进并引入负载电流前馈,以进一步提升控制器动、静态性能。首先,根据UPQC拓扑结构建立串联侧单相数学模型以分析扰动对系统影响;其次,依据数学模型提出改进的复合前馈控制策略;最后,通过实物试验,分别从不同工况验证了该控制策略在UPQC系统中的有效性及优越性。
