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Research on the Evaluation of Risk Control Schemes for Engineering Projects under Uncertain Environments
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作者 Xiaoyang Zeng Weizhe Shu 《Journal of Architectural Research and Development》 2025年第6期66-71,共6页
To effectively select risk control schemes in uncertain environments,this paper has proposed an analysis and evaluation method based on the fuzzy comprehensive evaluation method.Firstly,enterprises have adopted the br... To effectively select risk control schemes in uncertain environments,this paper has proposed an analysis and evaluation method based on the fuzzy comprehensive evaluation method.Firstly,enterprises have adopted the brainstorming method and the Delphi method to identify risks in engineering projects,and organized the identified risks in the form of checklists to facilitate further analysis.Secondly,the fuzzy comprehensive evaluation theory was introduced to determine the comparison matrix of each risk factor and its weight.Furthermore,the top five risk factors in terms of weight ranking were taken as the evaluation factors for the selection of risk control plans.The plans were scored through the weighted scoring method,and the optimal risk control plan was determined based on the score.Finally,the feasibility of the proposed selection technology was verified through A research example of the risk control plan assessment for the construction project of Enterprise A. 展开更多
关键词 Engineering projects Fuzzy comprehensive evaluation method Uncertain environment Risk control schemes
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Feedback control scheme of traffic jams based on the coupled map car-following model 被引量:6
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作者 周桐 孙棣华 +1 位作者 赵敏 李华民 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第9期203-208,共6页
Based on the pioneering work of Konishi et al. [Phys. Rev. E (1999) 60 4000], a new feedback control scheme is presented to suppress traffic jams based on the coupled map car-following model under the open boundary ... Based on the pioneering work of Konishi et al. [Phys. Rev. E (1999) 60 4000], a new feedback control scheme is presented to suppress traffic jams based on the coupled map car-following model under the open boundary condition. The effect of the safe headway on the traffic system is considered. According to the control theory, the condition under which traffic jams can be suppressed is analyzed. The results are compared with the previous results concerning congestion control. The simulations show that the suppression performance of our scheme on traffic jams is better than those of the previous schemes, although all the schemes can suppress traffic jams. The simulation results are consistent with theoretical analyses. 展开更多
关键词 traffic jam coupled map car-following model control scheme safe headway
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Design of process and control scheme for cyclohexanol production from cyclohexene using reactive distillation 被引量:1
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作者 Mingyuan Hu Hui Tian 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第12期96-105,共10页
Cyclohexanol is a commonly used organic compound.Currently,the most promising industrial process for synthesizing cyclohexanol,by cyclohexene hydration,suffers from a low conversion rate and difficult separation.In th... Cyclohexanol is a commonly used organic compound.Currently,the most promising industrial process for synthesizing cyclohexanol,by cyclohexene hydration,suffers from a low conversion rate and difficult separation.In this paper,a three-column process for catalytic distillation applicable in the hydration of cyclohexene to cyclohexanol was established to solve these.Simulation with Aspen Plus shows that the process has good advantages,the conversion of cyclohexene reached 99.3%,and the product purity was>99.2%.The stable operation of the distillation system requires a good control scheme.The design of the control scheme is very important.However,at present,the reactive distillation process for cyclohexene hydration is under investigation experimentally and by steady-state simulation.Therefore,three different plant-wide control schemes were established(CS1,CS2,CS3) and the position of temperature sensitive stage was selected by using sensitivity analysis method and singular value decomposition method.The Tyreus-Luyben empirical tuning method was used to tune the controller parameters.Finally,Aspen Dynamics simulation software was used to evaluate the performance of the three control schemes.By introducing ΔF±20% and χ_(ENE)±5%,comparison the changes in product purity and yield of the three different control schemes.By comparison,we can see that the control scheme CS3 has the best performance. 展开更多
关键词 Cyclohexene hydration Catalytic distillation control schemes Dynamic Simulation
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Admission Control Scheme for Handover Service in High-Speed Train Communication System 被引量:1
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作者 赵宜升 纪红 陈忠辉 《Journal of Shanghai Jiaotong university(Science)》 EI 2015年第6期670-675,共6页
Admission control in high-speed train communication system is quite different from admission control in traditional cellular networks. Conventional admission control strategies cannot be directly applied to this speci... Admission control in high-speed train communication system is quite different from admission control in traditional cellular networks. Conventional admission control strategies cannot be directly applied to this special communication scenario. In this paper, the problem of admission control for handover service is investigated in high-speed train communication environment. An admission control scheme considering bit error rate(BER)and bandwidth borrowing strategy is proposed. On the basis of admission control decision rule taking BER into account, a part of bandwidth obtained by compressing variable rate service in the networks is provided for handover services. The admission control scheme can admit handover services as more as possible while it guarantees the lowest data rate of different services in the networks. Simulation results show that the proposed admission control scheme has a better performance than existing admission control schemes. 展开更多
关键词 admission control scheme handover service high-speed train communication
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CONTROL SCHEMES FOR CMAC NEURAL NETWORK-BASED VISUAL SERVOING 被引量:1
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作者 Wang HuamingXi WenmingZhu JianyingDepartment of Mechanical andElectrical Engineering,Nanjing University of Aeronauticsand Astronautics,Nanjing 210016, China 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2003年第3期256-259,共4页
In IBVS (image based visual servoing), the error signal in image space should be transformed into the control signal in the input space quickly. To avoid the iterative adjustment and complicated inverse solution of im... In IBVS (image based visual servoing), the error signal in image space should be transformed into the control signal in the input space quickly. To avoid the iterative adjustment and complicated inverse solution of image Jacobian, CMAC (cerebellar model articulation controller) neural network is inserted into visual servo control loop to implement the nonlinear mapping. Two control schemes are used. Simulation results on two schemes are provided, which show a better tracking precision and stability can be achieved using scheme 2. 展开更多
关键词 CMAC Neural network control scheme Visual servoing
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Control schemes for synchronizing two subnetworks with weak couplings
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作者 张建宝 马忠军 张刚 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第1期148-153,共6页
In this paper, we propose a well-designed network model with a parameter and study full and partial synchronization of the network model based on the stability analysis. The network model is composed of a star-coupled... In this paper, we propose a well-designed network model with a parameter and study full and partial synchronization of the network model based on the stability analysis. The network model is composed of a star-coupled subnetwork and a globally coupled subnetwork. By analyzing the special coupling configuration, three control schemes are obtained for synchronizing the network model. Further analysis indicates that even if the inner couplings in each subnetwork are very weak, two of the control schemes are still valid. In particular, if the outer coupling weight parameter 0 is larger than (n2 - 2n)/4, or the subnetwork size n is larger than 02, the two subnetworks with weak inner couplings can achieve synchronization. In addition, the synchronizability is independent of the network size in case of 0 〈 0 〈 n/(n + 1 ). Finally, we carry out some numerical simulations to confirm the validity of the obtained control schemes. It is worth noting that the main idea of this paper also applies to any network consisting of a dense subnetwork and a sparse network. 展开更多
关键词 SYNCHRONIZATION weak coupling star-global network control scheme
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An Apparatus Design for the Vehicle Control Scheme in Personal Rapid Transit System
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作者 Jun-Ho Lee 《Journal of Mechanics Engineering and Automation》 2013年第5期325-333,共9页
A new transportation technology known as personal rapid transit (PRT) is being developed by multiple different companies around the world, and one system is under commercial operations in the United Kingdom. Each de... A new transportation technology known as personal rapid transit (PRT) is being developed by multiple different companies around the world, and one system is under commercial operations in the United Kingdom. Each design is different, but they all share a need to operate many automated transit vehicles at very close headways. Safe operation will require a level of control an order of magnitude above any current transit system. As a result, new techniques will be needed for the development and testing of the mechanical and control systems. In this paper an apparatus for developing and testing a PRT vehicle control scheme is demonstrated. This system is composed of independent modules that represent virtual vehicles, a central control system, a man-machine interface and a monitoring device. It can be used to implement and to evaluate the designed vehicle control algorithm. The vehicle control algorithm is designed and simulated in a combined simulation platform that consists of Matlab/Simulink and Labview Simulation Interface Toolkit. Simple operational scenarios are proposed for the testing of the proposed vehicle control apparatus. 展开更多
关键词 Personal rapid transit vehicle control scheme virtual vehicles safe operation headway.
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Design of Control Scheme for Variable Air Volume Air- conditioning System
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作者 Zhang Fan 《International Journal of Technology Management》 2014年第9期152-156,共5页
The air quantity of variable air volume system for the rooms and the total air quantity of the system changes with the change of room load. Combined with the system composition in the laboratory, the paper determines ... The air quantity of variable air volume system for the rooms and the total air quantity of the system changes with the change of room load. Combined with the system composition in the laboratory, the paper determines the control scheme of the variable air volume system, that is, indoor temperature-control, indoor positive pressure control, air distribution static pressure control, air-supply temperature control and new air volume control. The dotted lines with arrows mean the output signals from the control unit to actuator, and the solid lines with arrows represent the input signals from the actuator to the control unit. 展开更多
关键词 variable air volume AIR-CONDITIONER control scheme
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Overall Evaluation of the Control Schemes of Automobile Pollution and Its Multi-Target Decision
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作者 李多松 王淑贞 陈浩 《International Journal of Mining Science and Technology》 SCIE EI 1998年第1期61-65,共5页
Various control schemes of automobile pollution are comprehensively evaluated by using the weighting and feyzzy methods, from which several feasible schemes are selected, and then mulit-target decision is made by usin... Various control schemes of automobile pollution are comprehensively evaluated by using the weighting and feyzzy methods, from which several feasible schemes are selected, and then mulit-target decision is made by using the minimum distance and hierarcby analysis methods, for determining the optimal control methods of automobile pollution. 展开更多
关键词 AUTOMOBILE POLLUTION control schemeS overall evaluation MULTI-TARGET DECISION
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Control Scheme Discussion for Bottom Oil Slurry System of FCCU Fractionator
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作者 马涛 张国磊 +1 位作者 胡玉臣 董爱娜 《石油化工自动化》 CAS 2011年第6期25-27,共3页
流化催化裂化装置(FCCU)分馏塔底油浆系统的控制效果对整个装置的平稳安全运行具有重要意义。近年来国内新建了许多大型FCCU,既包含国内各设计院自己的技术,也有部分引进国外的工艺包,其分馏塔底油浆系统的控制方案也有多种形式。... 流化催化裂化装置(FCCU)分馏塔底油浆系统的控制效果对整个装置的平稳安全运行具有重要意义。近年来国内新建了许多大型FCCU,既包含国内各设计院自己的技术,也有部分引进国外的工艺包,其分馏塔底油浆系统的控制方案也有多种形式。总结了近年来国内新建FCCU常用的三种较为典型的油浆系统控制方案,阐述了各方案的特点,对其进行了简要的对比和分析。在此基础上尝试性地提出了这三种方案的适用场合,方便设计人员根据每个项目的特点设计合理的控制方案,达到最佳控制效果。 展开更多
关键词 催化裂化装置 分馏塔 油浆系统 控制方案
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GROUP VELOCITY CONTROL SCHEME WITH LOW DISSIPATION 被引量:3
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作者 程军波 傅德薰 马延文 《Chinese Journal of Aeronautics》 SCIE EI CSCD 2000年第3期138-145,共8页
In order to prevent smearing the discontinuity, a modified term is added to the third order Upwind Compact Difference scheme to lower the dissipation error. Moreover, the dispersion error is controled to hold back the... In order to prevent smearing the discontinuity, a modified term is added to the third order Upwind Compact Difference scheme to lower the dissipation error. Moreover, the dispersion error is controled to hold back the non physical oscillation by means of the group velocity control. The scheme is used to simulate the interactions of shock density stratified interface and the disturbed interface developing to vortex rollers. Numerical results are satisfactory. 展开更多
关键词 low dissipation error group velocity control upwind compact difference scheme interactions of shock density stratified interface
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Chaos Synchronization in the Belousov-Zhabotinsky Chemical Reaction by Adaptive Control Scheme 被引量:1
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作者 李艳妮 陈兰 +1 位作者 蔡遵生 赵学庄 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2002年第8期753-759,共7页
The adaptive synchronization scheme proposed by John and Amritkar was employed into the Belousov Zhabotinsky (BZ) 4 variable Montanator model system. By the parameter adjustment, chaos synchronization has been obta... The adaptive synchronization scheme proposed by John and Amritkar was employed into the Belousov Zhabotinsky (BZ) 4 variable Montanator model system. By the parameter adjustment, chaos synchronization has been obtained. Through calculating the transient time, the optimal combination of the stiffness constant and damping constant was obtained. Furthermore, the relationships among the transient time, conditional Lyapunov exponents, the stiffness constant and damping constant were discussed. Also, the BZ system with the adaptive synchronization scheme might be used for the communication purposes. 展开更多
关键词 CHAOS synchronization Belousov Zhabotinsky chemical reaction adaptive control scheme
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Reliability Evaluation of Wind Power Converter Under Fault-tolerant Control Scheme with Quantification of Temperature and Humidity Effects 被引量:1
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作者 Xueying Yu Bo Hu +4 位作者 Kaigui Xie Changzheng Shao Yunjie Bai Wenyuan Li Jinfeng Ding 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2023年第5期1700-1710,共11页
Wind power converter(WPC)is a key part of a wind power unit which delivers electric energy to power grid.Because of a large number of semiconductors,WPC has a high failure rate.This paper proposes a method to accurate... Wind power converter(WPC)is a key part of a wind power unit which delivers electric energy to power grid.Because of a large number of semiconductors,WPC has a high failure rate.This paper proposes a method to accurately evaluate the reliability of WPC,which is crucial for the design and maintenance of wind turbines.Firstly,the index of effective temperature(ET)is presented to quantify the effects of temperature and humidity on the semiconductor operation.A novel method is proposed to evaluate the lifetime and calculate the aging failure rates of the semiconductors considering the fluctuations of ET.Secondly,the failure mode and effect analysis(FMEA)of WPC is investigated based on the topology and control scheme.The conventional two-state reliability model of the WPC is extended to the multi-state reliability model where the partial working state under the fault-tolerant control scheme is allowed.Finally,a reliability evaluation framework is established to calculate the parameters of the WPC reliability model considering the variable failure rates and repair activities of semiconductors.Case studies are designed to verfify the proposed method using a practical wind turbine. 展开更多
关键词 Effective temperature(ET) fault-tolerant control scheme humidity reliability evaluation wind power converter(WPC)
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Control scheme of hexagonal modular multilevel direct converter for offshore wind power integration via fractional frequency transmission system 被引量:20
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作者 Yongqing MENG Bo LIU +3 位作者 Huiyong LUO Shuonan SHANG Haitao ZHANG Xifan WANG 《Journal of Modern Power Systems and Clean Energy》 SCIE EI 2018年第1期168-180,共13页
A fractional frequency transmission system(FFTS)is a promising solution to offshore wind power integration,for which the hexagonal modular multilevel converter(Hexverter)is an attractive choice for power conversion.Th... A fractional frequency transmission system(FFTS)is a promising solution to offshore wind power integration,for which the hexagonal modular multilevel converter(Hexverter)is an attractive choice for power conversion.The Hexverter has recently been proposed to directly connect two three-phase systems of different frequencies and voltage amplitudes,with only six branches in the FFTS in that case.This paper examines for the first time the control scheme of the Hexverter when applied to offshore wind power integration via a FFTS.Firstly,the frequency-decoupled mathematical model of the Hexverter is deduced by introducing the double dq transformation.Then the branch energy of the Hexverter is analyzed in detail and the reactive power constraint equation is obtained.The corresponding control scheme is thoroughly discussed,including the inner loop current control,the outer loop voltage control in both grid-connected mode and passive mode,and a novel optimization method to minimize the circulating current in the Hexverter.Finally,a simulation model of offshore wind power integration via a 4-terminal FFTS based on the Hexverter is built in MATALB/Simulink to verify the feasibility of Hexverter and the effectiveness of the control scheme proposed in this paper. 展开更多
关键词 HEXAGONAL MODULAR MULTILEVEL converter(Hexverter) Offshore wind power integration FRACTIONAL frequency transmission system(FFTS) control scheme CIRCULATING current optimization
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Optimized and coordinated model predictive control scheme for DFIGs with DC-based converter system 被引量:5
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作者 Shaomin YAN Aimin ZHANG +2 位作者 Hang ZHANG Jianhua WANG Bin CAI 《Journal of Modern Power Systems and Clean Energy》 SCIE EI 2017年第4期620-630,共11页
This paper proposes an optimized and coordinated model predictive control(MPC) scheme for doublyfed induction generators(DFIGs) with DC-based converter system to improve the efficiency and dynamic performance in DC gr... This paper proposes an optimized and coordinated model predictive control(MPC) scheme for doublyfed induction generators(DFIGs) with DC-based converter system to improve the efficiency and dynamic performance in DC grids. In this configuration, the stator and rotor of the DFIG are connected to the DC bus via voltage source converters, namely, a rotor side converter(RSC) and a stator side converter(SSC). Optimized trajectories for rotorflux and stator current are proposed to minimize Joule losses of the DFIG, which is particularly advantageous at low and moderate torque. The coordinated MPC scheme is applied to overcome the weaknesses of the field-oriented control technique in the rotor flux-oriented frame, which makes the rotor flux stable and the stator current track its reference closely and quickly. Lastly, simulations and experiments are carried out to validate the feasibility of the control scheme and to analyze the steady-state and dynamic performance of the DFIG. 展开更多
关键词 Coordinated model predictive control(MPC)scheme Doubly-fed induction generator(DFIG) DC-based converter system Optimized trajectories Rotor side converter(RSC) Stator side converter(SSC)
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Threshold Controlled Scheme of Difference Expansion Techniques for Reversible Watermarking
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作者 蒋历军 郭小涛 +2 位作者 杨浩 赵俊 庄天戈 《Journal of Shanghai Jiaotong university(Science)》 EI 2010年第5期541-548,共8页
Since Tian Jun proposed the difference expansion embedding technique,based on which,many reversible watermarking techniques were proposed.However,these methods do not perform well when the payload is high.In this pape... Since Tian Jun proposed the difference expansion embedding technique,based on which,many reversible watermarking techniques were proposed.However,these methods do not perform well when the payload is high.In this paper,we proposed an expandable difference threshold controlled scheme for these three methods.Experiments show that our scheme improves the performance of these three methods for heavy payload. 展开更多
关键词 difference expansion embedding technique reversible watermarking visual quality difference threshold controlled scheme
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Scheme of Control Agreement between CLP Power andHong Kong SAR Government
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《Electricity》 1998年第2期14-16,共3页
关键词 CLP SAR Hong Kong SAR Government scheme of control Agreement between CLP Power and
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面向数字孪生水网的智能水闸建设方案研究
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作者 梁云辉 熊飞 +3 位作者 谭宇翔 肖怀前 殷振兴 李文明 《江苏水利》 2026年第2期39-43,共5页
智能水闸建设是推进智慧水利体系构建的重要环节,对提升水利工程管理现代化水平具有重要意义。分析传统水闸运行管理模式的局限性,提出以采集自动化、信息数字化、通信网络化、业务智能化、决策最优化为技术特征的智能水闸建设方案。通... 智能水闸建设是推进智慧水利体系构建的重要环节,对提升水利工程管理现代化水平具有重要意义。分析传统水闸运行管理模式的局限性,提出以采集自动化、信息数字化、通信网络化、业务智能化、决策最优化为技术特征的智能水闸建设方案。通过阐述智能基础设施、数据服务平台、智能应用系统三层功能架构的建设内容与技术路径,构建面向数字孪生水网的智能水闸系统化建设框架。结合沭新闸智能化改造实践,探讨该方案在工程应用中的可行性与有效性,为同类水利工程的智能化升级提供了理论参考与实践指导。 展开更多
关键词 智能水闸 智慧水利 自动化控制 建设方案 数字孪生
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马鞍山长江公铁大桥主航道桥总体施工方案研究
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作者 周功建 沈大才 +1 位作者 赵鹍鹏 刘爱林 《桥梁建设》 北大核心 2026年第1期1-8,共8页
马鞍山长江公铁大桥主航道桥为双主跨1120 m的三塔钢桁梁斜拉桥,桥塔墩基础采用超大直径钻孔桩;桥塔采用钢-混组合结构,Z4号中塔为四肢空间结构,纵、横向均为A形,塔高345 m;主梁采用钢桁梁,3片主桁、N形桁式。针对该桥的结构特点、施工... 马鞍山长江公铁大桥主航道桥为双主跨1120 m的三塔钢桁梁斜拉桥,桥塔墩基础采用超大直径钻孔桩;桥塔采用钢-混组合结构,Z4号中塔为四肢空间结构,纵、横向均为A形,塔高345 m;主梁采用钢桁梁,3片主桁、N形桁式。针对该桥的结构特点、施工环境、技术难点、工期要求,系统考虑了场地布设、关键线路、资源配置、绿色环保、智能工装等因素,Z3号边塔墩基础施工采用吹砂筑岛形成钻孔平台方案,实现了基础快速施工;Z4号中塔墩采用矩形双壁钢套箱围堰施工,底节双壁钢围堰采用模块化浮态拼装入水方案,实现了围堰快速拼装,围堰封底混凝土采用分区不等厚、不同强度的精细封底方案,解决了承台中部封底混凝土跨度大、受力复杂的问题;混凝土塔柱采用集成化智能液压爬模施工,研发低收缩抗裂混凝土及智能养护系统以控制混凝土开裂,钢塔部位大节段采用新研制的15000-600S超级智能塔吊吊装,钢-混结合段采用“可调支撑架+定位匹配架”方案精确定位,解决了空间四肢钢-混结合段精确就位难题;四肢钢塔采用定位桁架还原工厂总拼法,实现了精确合拢;钢桁梁采用边辅跨顶推架设+主跨悬臂拼装架设方案,施工组织难度小,对周边环境和地形地貌影响小;通过智能、动态精确监测全过程线形关联参数技术,结合合龙敏感性分析,实现了主梁精确合龙及成桥线形精准控制。 展开更多
关键词 公路铁路两用桥 三塔斜拉桥 超大直径钻孔桩基础 钢-混组合塔 钢桁梁 线形控制 施工方案
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Single-molecule electroluminescence in molecular junctions
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作者 Shaojia Li Cong Zhao +3 位作者 Suhang He Mingliang Li Chuangcheng Ji Xuefeng Guo 《Science Bulletin》 2026年第3期477-481,共5页
Single-molecule electroluminescence(SMEL)confines light emission to a well-defined molecular junction,creating a unique platform for probing light-matter interactions at the ultimate spatial limit.This perspective arg... Single-molecule electroluminescence(SMEL)confines light emission to a well-defined molecular junction,creating a unique platform for probing light-matter interactions at the ultimate spatial limit.This perspective argues that four controllable levers—nanocavity plasmons,interface engineering,electric-field modulation,and molecular design—collectively govern the quantum efficiency,spectral characteristics,and excited-state dynamics of SMEL[1].This multifaceted control scheme opens up pathways to transformative technologies,including quantum light sources,single-molecule light-emitting diodes(LEDs),andprogrammable optoelectronic chips. 展开更多
关键词 single molecule electroluminescence molecular design collectively multifaceted control scheme electric field modulation molecular design quantum efficiency plasmonsinterface engineeringelectric field nanocavity plasmons
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