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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

改进范式下的英国高校社会服务评估探索——对“知识交换协定”的考察

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中国高教研究 2024年第7期 73-79页

作者：马星南京信息工程大学高等教育研究所江苏南京210044

为通过评估促进高校发挥社会服务职能,英国在2017年提出“知识交换框架”项目的同时,也基于评估的改进范式提出“知识交换协定”项目。从2020年到2021年,“知识交换协定”对英国高校知识交换活动展开了初始评估,项目以质量改进为根本目... 详细信息

为通过评估促进高校发挥社会服务职能,英国在2017年提出“知识交换框架”项目的同时,也基于评估的改进范式提出“知识交换协定”项目。从2020年到2021年,“知识交换协定”对英国高校知识交换活动展开了初始评估,项目以质量改进为根本目的,注重对知识交换活动内在机制考察,支持价值多元,促进评估者与被评估者合作共创,对英国高校知识交换的内部改进产生了显著影响。英国在改进范式下对高校社会服务的评估探索对我国加快构建完善的高校社会服务评估体系具有重要借鉴意义。

关键词：改进范式高校社会服务高校评估英国

Nonlinear Characteristic Analysis of Gas-Interconnected Quasi-Zero Stiffness Pneumatic Suspension System:A Theoretical and Experimental Study

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 338-352页

作者： Xinwei Jiang xing Xu Tianling Shi Vincent Akolbire Atindana Automotive Engineering Research Institute Jiangsu UniversityZhenjiang 212013China

Because of significantly changed load and complex and variable driving road conditions of commercial vehicles,pneumatic suspension with lower natural frequencies is widely used in commercial vehicle suspension *** ever,traditional pneumatic suspension system is hardly to respond the greatly changed load of commercial vehicles To address this issue,a new Gas-Interconnected Quasi-Zero Stiffness Pneumatic Suspension(GIQZSPS)is presented in this paper to improve the vibration isolation performance of commercial vehicle suspension systems under frequent load *** new structure adds negative stiffness air chambers on traditional pneumatic suspension to reduce the natural frequency of the *** can adapt to different loads and road conditions by adjusting the solenoid valves between the negative stiffness air ***,a nonlinear mechanical model including the dimensionless stiffness characteristic and interconnected pipeline model is derived for GIQZSPS *** the nonlinear mechanical model of GIQZSPS system,the force transmissibility rate is chosen as the evaluation index to analyze ***,a testing bench simulating 1/4 GIQZSPS system is designed,and the testing analysis of the model validation and isolating performance is carried *** results show that compared to traditional pneumatic suspension,the GIQZSPS designed in the article has a lower natural *** the system can achieve better vibration isolation performance under different load states by switching the solenoid valves between air chambers.

关键词： Pneumatic suspension Quasi-zero stiffness system Gas-interconnected system Nonlinear dynamic modeling

Configuration Synthesis and Grasping Performance Analysis of Multi-Loop Coupling Capture Mechanism for Launch and Recovery of Torpedo-Shaped Autonomous Underwater Vehicle

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China Ocean Engineering 2024年第3期38卷 453-466页

作者： ZHANG Guo-xing XIA Xin-lu GUO Jin-wei School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

Research of capture mechanisms with strong capture adaptability and stable grasp is important to solve the problem of launch and recovery of torpedo-shaped autonomous underwater vehicles(AUVs).A multi-loop coupling capture mechanism with strong adaptability and high retraction rate has been proposed for the launch and recovery of torpedo-shaped AUVs with different morphological ***,the principle of capturing motion retraction is described based on the appearance characteristics of torpedo-shaped AUVs,and the configuration synthesis of the capture mechanism is carried out using the method of constrained chain ***,the screw theory is employed to analyze the degree of freedom(DoF)of the capture ***,the 3D model of the capture mechanism is established,and the kinematics and dynamics simulations are carried *** with the capture orientation requirements of the capture mechanism,the statics and vibration characteristics analyses are carried ***,considering the capture process and the underwater working environment,the motion characteristics and hydraulics characteristics of the capture mechanism are ***,a principle prototype is developed and the torpedo-shaped AUVs capture experiment is *** work provides technical reserves for the research and development of AUV capture special equipment.

关键词： capture mechanism torpedo-shaped AUVs configuration synthesis launch and recovery grasping performance analysis

Quantitative characterizations of anisotropic dynamic properties in organic-rich shale with different kerogen content

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Petroleum Science 2024年第2期21卷 855-865页

作者： Jian-Yong Xie Yan-Ping Fang xing-Hua Wu Jian'er Zhao Jun-Cheng Dai Jun-xing Cao Ji-Xin Deng State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu610059SichuanChina Key Lab of Earth Exploration&Information Techniques of Ministry of Education Geophysical InstituteChengdu University of TechnologyChengdu610059SichuanChina PetroChina Southwest Oil&Gasfield Company Chengdu610017SichuanChina

Understanding the quantitative responses of anisotropic dynamic properties in organic-rich shale with different kerogen content(KC)is of great significance in hydrocarbon exploration and *** controlled experiments with a single variable is challenging for natural shales due to their high variations in components,diagenesis conditions,or pore *** employed the hot-pressing technique to construct 11 well-controlled artificial shale with varying *** artificial shale samples were successive machined into prismatic shape for ultrasonic measurements along different *** revealed bedding perpendicular P-wave velocities are more sensitive to the increasing KC than bedding paralleling velocities due to the preferential alignments of *** elastic stiffnesses except C_(13)are generally decreasing with the increasing KC,the variation of C_(1) and C_(33)on kerogen content are more sensitive than those of C_(44)and C_(66).Apparent dynamic mechanical parameters(v and E)were found to have linear correlation with the true ones from complete anisotropic equations independent of KC,which hold value towards the interpretation of well logs consistently across formations,Anisotropic mechanical parameters(ΔE and brittlenessΔB)tend to decrease with the reducing KC,withΔB showing great sensitivity to KC *** the range of low KC(magnitude of less than 1.75may serve as a significant characterization for highly organic-rich(>10%)shale,compilation of data from natural organic rich-shales globally verified the similar systematic relationships that can be empirically used to predict the fraction of KC in shales.

关键词： Elastic properties Organic shale Anisotropy Kerogen content Physical modeling

In-situ embedded ultrafine Bi_(12)O_(17)Br_(2)nanotubes in MOF-derived hierarchical porous carbon for enhanced photocatalytic CO_(2)conversion to CO

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Journal of materials Science & Technology 2024年第4期171卷 47-53页

作者： xing Sun Mengxia Ji Yi Zhang Qingzeng xing Zihan Liu Nianhua Liu Emmanuel Nkudede Huaming Li Sheng Yin Jiexiang Xia School of Chemistry and Chemical Engineering Institute for Energy ResearchJiangsu UniversityZhenjiang 212013China Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources Qinghai Provincial Key Laboratory of Resources Chemistry of Salt LakesQinghai Institute of Salt LakesChinese Academy of SciencesXining 81008China

Increasing the utilization efficiency of photogenerated electrons is highly recognized as one of the ef-ficient approaches to boost the photocatalytic CO_(2)conversion ***,ZIF-67-derived porous carbon(PC)material was employed for the construction of PC@ultrafine Bi_(12)O_(17)Br_(2)nanotubes(PC@BOB NTs)composites through a facile solvothermal synthesis in order to optimize the use of excited elec-trons in the BOB *** characterization results revealed that the introduction of PC material achieved a faster charge separation rate in the PC@BOB composites,ensuring more photogener-ated electrons participate in the CO_(2)adsorption and activation ***,the pore structures of ZIF-67-derived PC material provided abundant confined spaces for the enrichment of CO_(2)***-ter 5 h of Xenon lamp irradiation,PC@BOB composites exhibited obviously increased photocatalytic CO_(2)reduction activity in the pure *** the addition amount of PC was 5 wt%,the PC@BOB-2 com-posite showed the highest CO evolution rate of 359.70μmol/g,which was 2.95 times higher than that of the pure BOB *** work provides some independent insights into the applications of Metal-Organic Framework(MOF)-derived hierarchical porous structures to strengthen the CO_(2)enrichment,as well as the excited charge utilization efficiency,thus achieving a high solar-to-fuel conversion efficiency.

关键词： Bi_(12)O_(17)Br_(2)nanotubes Hierarchical porous structure CO_(2)enrichment Charge separation CO_(2)photoreduction

LPCS Ni-Zn-Al_(2)O_(3) Intermediate Layer Enhanced SPS NiCr-Cr_(3)C_(2) Coating with Higher Corrosion and Wear Resistances

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Journal of Wuhan University of Technology(materials Science) 2024年第1期39卷 188-195页

作者：白杨 LI Yan xing Lukuo LI Xiangbo WANG Zhenhua State Key Laboratory of marine Coatings Marine Chemical Research Institute Co.Ltd.Qingdao 266071China College of Mechanical and Electrical Engineering University of China Petroleum(East China)Qingdao 266580China Science and Technology on marine Corrosion and Protection Laboratory Luoyang Ship Materials Research InstituteQingdao 266101China

The double-layer NiCr-Cr_(3)C_(2)/Ni-Zn-Al_(2)O_(3) coatings with sufficient corrosion and wear resistance were prepared on low carbon steel *** intermediate layers Ni-Zn-Al_(2)O_(3) were fabricated by using low-pressure cold spray (LPCS) method to improve the salt fog corrosion resistance properties of the supersonic plasma spray (SPS) NiCr-Cr_(3)C_(2) *** friction and wear performance for the double-layer and single-layer NiCr-Cr_(3)C_(2) coatings were carried out by line-contact reciprocating sliding,*** with the coating surface analysis techniques,the effect of the salt fog corrosion on the tribological properties of the double-layer coatings was *** results showed that the double-layer coatings exhibited better wear resistance than that of the single-layer coatings,due to the better corrosion resistance of the intermediate layer;the wear mass losses of the double-layer coatings was reduced by 70%than that of the single layer coatings and the wear mechanism of coatings after salt fog corrosion conditions is mainly corrosion wear.

关键词： low-pressure cold spray NiCr-Cr_(3)C_(2)coating wear behavior salt fog corrosion

Stability and Time-Step Constraints of Implicit-Explicit Runge-Kutta Methods for the Linearized Korteweg-de Vries Equation

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Communications on Applied mathematics and Computation 2024年第1期6卷 658-687页

作者： Joseph Hunter Zheng Sun Yulong xing Department of mathematics The Ohio State UniversityColumbusOH43210USA Department of mathematics The University of AlabamaTuscaloosaAL35487USA

This paper provides a study on the stability and time-step constraints of solving the linearized Korteweg-de Vries(KdV)equation,using implicit-explicit(IMEX)Runge-Kutta(RK)time integration methods combined with either finite difference(FD)or local discontinuous Galerkin(DG)spatial *** analyze the stability of the fully discrete scheme,on a uniform mesh with periodic boundary conditions,using the Fourier *** the linearized KdV equation,the IMEX schemes are stable under the standard Courant-Friedrichs-Lewy(CFL)conditionτ≤λ***,λis the CFL number,τis the time-step size,and h is the spatial mesh *** study several IMEX schemes and characterize their CFL number as a function ofθ=d/h^(2)with d being the dispersion coefficient,which leads to several interesting *** also investigate the asymptotic behaviors of the CFL number for sufficiently refined meshes and derive the necessary conditions for the asymptotic stability of the IMEX-RK *** numerical experiments are provided in the paper to illustrate the performance of IMEX methods under different time-step constraints.

关键词： Linearized Korteweg-de Vries(KdV)equation Implicit-explicit(IMEX)Runge-Kutta(RK)method Stability Courant-Friedrichs-Lewy(CFL)condition Finite difference(FD)method Local discontinuous Galerkin(DG)method

Convolutional neural network adaptation and optimization method in SIMT computing mode

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The Journal of China Universities of Posts and Telecommunications 2024年第2期31卷 105-112页

作者： Feng Zhenfu Zhang Yaying Yang Lele xing Lidong School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'an 710121China

For studying and optimizing the performance of general-purpose computing on graphics processing units(GPGPU)based on single instruction multiple threads(SIMT)processor about the neural network application,this work contributes a self-developed SIMT processor named Pomelo and correlated assembly *** parallel mechanism of SIMT computing mode and self-developed Pomelo processor is briefly introduced.A common convolutional neural network(CNN)is built to verify the compatibility and functionality of the Pomelo *** computing flow with task level and hardware level optimization is adopted on the Pomelo processor.A specific algorithm for organizing a Z-shaped memory structure is developed,which addresses reducing memory access in mass data computing *** the above-combined adaptation and optimization strategy,the experimental result demonstrates that reducing memory access in SIMT computing mode plays a crucial role in improving performance.A 6.52 times performance is achieved on the 4 processing elements case.

关键词： parallel computing single instruction multiple threads(SIMT) convolutional neural network(CNN) memory optimization

Seasonal Variation of the Sea Surface Temperature Growth Rate of ENSO

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Advances in Atmospheric Sciences 2024年第3期41卷 465-477页

作者： Xinyi xing Xianghui FANG Da PANG Chaopeng JI Department of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China Shanghai Frontiers Science Center of Atmosphere-Ocean Interaction Shanghai 200438China Shanghai Key Laboratory of Ocean-land-atmosphere Boundary Dynamics and Climate Change Fudan UniversityShanghai 200438China

El Ni?o–Southern Oscillation(ENSO) exhibits a distinctive phase-locking characteristic, first expressed during its onset in boreal spring, developing during summer and autumn, reaching its peak towards winter, and decaying over the next spring. Several studies have demonstrated that this feature arises as a result of seasonal variation in the growth rate of ENSO as expressed by the sea surface temperature(SST). The bias towards simulating the phase locking of ENSO by many state-of-the-art climate models is also attributed to the unrealistic depiction of the growth rate. In this study, the seasonal variation of SST growth rate in the Ni?o-3.4 region(5°S–5°N, 120°–170°W) is estimated in detail based on the mixed layer heat budget equation and recharge oscillator model during 1981–2020. It is suggested that the consideration of a variable mixed layer depth is essential to its diagnostic process. The estimated growth rate has a remarkable seasonal cycle with minimum rates occurring in spring and maximum rates evident in autumn. More specifically, the growth rate derived from the meridional advection(surface heat flux) is positive(negative) throughout the year. Vertical diffusion generally makes a negative contribution to the evolution of growth rate and the magnitude of vertical entrainment represents the smallest contributor. Analysis indicates that the zonal advective feedback is regulated by the meridional immigration of the intertropical convergence zone, which approaches its southernmost extent in February and progresses to its northernmost location in September, and dominates the seasonal variation of the SST growth rate.

关键词： SST growth rate intertropical convergence zone zonal advective feedback mixed layer depth ENSO seasonal variation