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沼气-汽油混合发动机研究

重庆理工大学学报（自然科学） 2019年第1期33卷 162-165页

作者：杜丹丰牛文林郭秀荣东北林业大学交通学院哈尔滨150040

在KG144型汽油发动机基础上,将其改造成沼气汽油混合发动机。该发动机在启动和怠速时使用汽油燃料,而全功率时使用沼气燃料。发动机转速通过沼气阀和混合阀组成的调控装置自动调节,沼气阀和混合阀之间的运动关系已设定。发动机使用沼气... 详细信息

在KG144型汽油发动机基础上,将其改造成沼气汽油混合发动机。该发动机在启动和怠速时使用汽油燃料,而全功率时使用沼气燃料。发动机转速通过沼气阀和混合阀组成的调控装置自动调节,沼气阀和混合阀之间的运动关系已设定。发动机使用沼气与汽油产生1kW电力,每小时消耗1 m^3沼气,减少1 kg的CO_2排放,HC排放量也减少了60%以上。这种新的调控装置使发动机运行非常稳定,发电机组输出电压稳定,输出电压波动小于正常值的5%。

关键词：沼气发动机自动调控减排

Sparse Modal Decomposition Method Addressing Underdetermined Vortex-Induced Vibration Reconstruction Problem for Marine Risers

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China Ocean Engineering 2024年第2期38卷 285-296页

作者： du Zun-feng ZHU Hai-ming YU Jian-xing State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation School of Civil EngineeringTianjin UniversityTianjin 300350China

When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fatigue monitoring of real *** problem is conventionally solved using the modal decomposition method,based on the principle that the response can be approximated by a weighted sum of limited vibration ***,the method is not valid when the problem is underdetermined,i.e.,the number of unknown mode weights is more than the number of known *** study proposed a sparse modal decomposition method based on the compressed sensing theory and the Compressive Sampling Matching Pursuit(Co Sa MP)algorithm,exploiting the sparsity of VIV in the modal *** the validation study based on high-order VIV experiment data,the proposed method successfully reconstructed the response using only seven acceleration measurements when the conventional methods failed.A primary advantage of the proposed method is that it offers a completely data-driven approach for the underdetermined VIV reconstruction problem,which is more favorable than existing model-dependent solutions for many practical applications such as riser structural health monitoring.

关键词： motion reconstruction vortex-induced vibration(VIV) marine riser modal decomposition method compressed sensing

Evaluation of CMIP6 model performance in simulating the PDO and its future change

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Atmospheric and Oceanic Science Letters 2024年第3期17卷 8-13页

作者： Yuchun du Huopo Chen Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina Colaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjingChina University of Chinese Academy of Sciences BeijingChina

本文基于40个CMIP6模式输出结果,系统评估了模式对历史时期太平洋年代际振荡(PDO)的模拟性能,并利用其中17个模式的4种共享社会经济路径情景数据预估了PDO未来可能变化趋势.结果表明,CMIP6模式能够合理再现PDO相关海表温度异常的空间模... 详细信息

本文基于40个CMIP6模式输出结果,系统评估了模式对历史时期太平洋年代际振荡(PDO)的模拟性能,并利用其中17个模式的4种共享社会经济路径情景数据预估了PDO未来可能变化趋势.结果表明,CMIP6模式能够合理再现PDO相关海表温度异常的空间模态,但模式模拟PDO位相演变的能力普遍较弱.多模式集合能够合理再现PDO的50年左右周期,但无法模拟出其20年左右周期,并且低估了PDO的变化幅度.在未来变暖情景下,PDO可能在2050左右出现由负位相向正位相的转变,同时其50年左右周期也将明显缩短.

关键词：太平洋年代际振荡预估多模式集合 CMIP6

Anti-saturation fault-tolerant adaptive torsional vibration control with fixed-time prescribed performance for rolling mill main drive system

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Journal of Iron and Steel Research International 2024年第3期31卷 660-669页

作者： Shuang Liu Chen du Cong Zhang Zhen-hua Bai Key Lab of Industrial Computer Control Engineering of Hebei Province Yanshan UniversityQinhuangdao 066004HebeiChina National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao 066004HebeiChina

An anti-saturation fault-tolerant adaptive torsional vibration control method with fixed-time prescribed performance for the rolling mill main drive system(RMMDS)was investigated,which is affected by control input saturation,actuator faults,sensor measurement errors,and parameter ***,we gave a continuously differentiable saturation function to approximate the control input saturation characteristic of the RMMDS,translating the saturation characteristic into the matched uncertainty and unknown time-varying gain in the ***,an RMMDS mathematical model with unmatched uncertainty and unknown time-varying gain was developed,taking into account the presence of control input saturation,actuator faults,sensor measurement errors,and parameter *** on the established mathematical model,an error transformation model of the roll speed tracking was constructed by the equivalent error transformation *** to the error transformation model,a barrier Lyapunov function and a novel adaptive controller were studied to ensure that the roll speed tracking error always evolves inside a fixed-time asymmetric ***,numerical simulations were performed in Matlab/Simulink to verify the effectiveness and superiority of the proposed control method in suppressing the RMMDS torsional vibration.

关键词： Fixed-time prescribed performance Control input saturation Actuator fault Unknown time-varying gain Adaptive control Asymmetric constraint

Toeplitz Operators and Carleson Measures for Weighted Bergman Spaces Induced by Regular Weights

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1345-1359页

作者： Jun Tao du Song Xiao Hasi WULAN Department of Mathematics Guangdong University of Petrochemical TechnologyMaoming 525000P.R.China Department of Mathematics Shantou UniversityShantou 515063P.R.China

In this paper,we give a universal description of the boundedness and compactness of Toeplitz operator T_(μ)^(ω)between Bergman spaces A_(η)^(p)and A_(υ)^(q)whenμis a positive Borel measure,1 详细信息

关键词： Bergman space Carleson measure Toeplitz operator regular weight

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汽车木陶瓷制动衬片热弹性耦合分析

重庆理工大学学报（自然科学） 2023年第2期37卷 134-141页

作者：杜丹丰王麒麟郭秀荣东北林业大学交通学院哈尔滨150040 东北林业大学机电工程学院哈尔滨150040

提出了一种以木陶瓷为原料的汽车制动衬片,建立了木陶瓷制动衬片的盘式制动器三维模型,模拟多种工况制动时木陶瓷制动衬片作用下盘式制动器的热弹性耦合特性,并基于Archard磨损模型及ABAQUS软件中的UMESHMOTION子程序实现木陶瓷制动衬... 详细信息

提出了一种以木陶瓷为原料的汽车制动衬片,建立了木陶瓷制动衬片的盘式制动器三维模型,模拟多种工况制动时木陶瓷制动衬片作用下盘式制动器的热弹性耦合特性,并基于Archard磨损模型及ABAQUS软件中的UMESHMOTION子程序实现木陶瓷制动衬片磨损深度的数值模拟。结果表明:以木陶瓷材料作为汽车制动摩擦材料,制动过程中制动盘温度峰值为254.25℃,相较于传统金属型制动衬片制动盘温度峰值低9.91℃,应力分布均匀,有利于减少制动盘热裂纹的产生,同时降低制动盘“热衰退”效应对车辆制动效能稳定性的影响。木陶瓷制动衬片制动过程中温度最高可达281.41℃,远低于木陶瓷材料热分解温度,具备良好的可靠性。以木陶瓷作为制动衬片摩擦材料,单次高速紧急制动磨损深度最大不超过2.11μm,具备良好的耐磨性。

关键词：汽车木陶瓷制动衬片热弹性耦合磨损

Tailoring the Microstructure and Mechanical Property of Mg-Zn Matrix Composite via the Addition of Al Element

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 438-452页

作者： Chong Wang Fuyuan Liu Xuejian Wang Enyu Guo Zelong du Kunkun Deng Zongning Chen Huijun Kang Guohao du Tongmin Wang Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116024China School of Mechanical Engineering Guizhou UniversityGuiyang 550025China Ningbo Institute of Dalian University of Technology Ningbo 315000China Shanxi Key Laboratory of Advanced Magnesium-Based Materials College of Materials Science and EngineeringTaiyuan University of TechnologyTaiyuan 030024China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research Institute CASShanghai 201204China

The semi-solid stir casting method is adopted to prepare 10 wt%SiC_(p)/Mg-6Zn-0.5Ca-xAl(x=0,1,3 and 5 wt%)composites,and the microstructure evolution and mechanical property of composites with various Al content are *** results show that the addition of 3 wt%Al improves the distribution of SiC_(p),whereas the SiC_(p) cluster occurs again with Al content greater than 3%.An abnormal phenomenon of twinning is observed in the cast composites in this *** SiC_(p)/Mg-6Zn-0.5Ca composite possesses the highest twin content of~23%,for which tension twins(TTW)and compression twins(CTW)account for~19%and~3%,*** CTW is only observed in ZXA600 *** addition of Al has an inhibiting effect for the generation and growth of *** content of twin decreases firstly and then increases with increase of Al *** lowest twin content is obtained as Al increases to 3 wt%.It is found the existence of twin is detrimental to the mechanical property of ***-cast SiC_(p)/Mg-6Zn-0.5Ca-3Al composite with the lowest twin content exhibits the optimal mechanical property of yield strength,ultimate tensile strength and elongation for 100 MPa,188 MPa and 4.4%,*** outstanding mechanical property is attributed to the uniform distribution of SiC_(p),the low twin content and the well-distributed fine second phases.

关键词： Mg matrix composite Synchrotron tomography Twinning Liquid melt processing Mechanical property

Fast-Charging Sodium-Ion Batteries Enabled by Molecular-Level Designed Nitrogen and Phosphorus Codoped Mesoporous Soft Carbon

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Research 2024年第2期2023卷 329-337页

作者： Lei Liu Zhuzhu du Jiaqi Wang Hongfang du Sheng Wu Mengjun Li Yixuan Zhang Jinmeng Sun Zhipeng Sun Wei Ai Frontiers Science Center for Flexible Electronics(FSCFE)and Shaanxi Institute of Flexible Electronics(SIFE) Northwestern Polytechnical University(NPU)127 West Youyi RoadXi'an 710072China Fujian Cross Strait Institute of Flexible Electronics(Future Technologies) Fujian Normal UniversityFuzhou 350117China School of Materials and Energy Guangdong University of TechnologyGuangzhou510006 GuangdongChina

Soft carbons have attracted extensive interests as competitive anodes for fast-charging sodium-ion batteries(SIBs);however,the high-rate performance is still restricted by their large ion migration barriers and sluggish reaction ***,we show a molecular design approach toward the fabrication of nitrogen and phosphorus codoped mesoporous soft carbon(NPSC).The key to this strategy lies in the chemical cross-linking reaction between polyphosphoric acid and p-phenylenediamine,associated with pyrolysis induced in-situ self-activation that creates mesoporous structures and rich heteroatoms within the carbon *** to the enlarged interlayer spacing,reduced ion diffusion length,and plentiful active sites,the obtained NPSC delivers a superb rate capacity of 215 mAh g-1 at 10 A g-1 and an ultralong cycle life of 4,700 cycles at 5 A g^(-1).Remarkably,the full cell shows 99%capacity retention during 100 continuous cycles,and maximum energy and power densities of 191 Wh kg^(-1)and 9.2 kW kg^(-1),*** believe that such a synthetic protocol could pave a novel venue to develop soft carbons with unique properties for advanced SIBs.

关键词： kinetics carbons linking

Advancing neuroscience through real-time processing of big data:Transition from open-loop to closed-loop paradigms

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Zoological Research 2024年第3期45卷 518-519页

作者： Yu-Fan Wang Jiu-Lin du Institute of Neuroscience State Key Laboratory of NeuroscienceCenter for Excellence in Brain Science and Intelligence TechnologyChinese Academy of SciencesShanghai 200031China University of Chinese Academy of Sciences Beijing 100049China School of Life Science and Technology ShanghaiTech UniversityShanghai 200031China

The brain functions as a closed-loop system that continuously generates behavior in response to the external environment and adjusts actions based on the *** research methodologies in neuroscience,especially those employed in brain imaging experiments,have mainly adopted an open-loop paradigm(Grosenick et al.,2015).Functional neural circuits are analyzed offline and subsequently tested through manipulation of neuronal activities within specific regions or with genetic *** establishing a closed-loop research paradigm,functional ensembles can be detected and tested in real time with temporal *** functional ensembles,rather than brain regions or genetically labeled neural populations,serve as fundamental units of neural networks,offering valuable insights into the dissection of neural *** closed-loop research paradigm also enables the capture of high-dimensional activities of internal brain dynamics and precise elucidation of physiological processes such as learning,decision-making,and sleep.

关键词： neural loop Transition