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Tracking of horizontal alignment of the long and large diameter uncharged hole in NATM tunnel

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Underground Space 2024年第3期16卷 18-28页

作者： min-Seong Kim Sean Seungwon Lee Department of Energy and Resources Engineering Chonnam National UniversityGwangju 61186Republic of Korea Department of Earth Resources and Environmental Engineering Hanyang UniversitySeoul 04763Republic of Korea

The long and large diameter uncharged hole boring(LLB)method is a cut blasting method that minimizes blast-induced vibrations by creating long and large diameter uncharged holes at the excavation face of tunnels prior to tunnel *** in this method typically uses a 50 m long with a 382.mm diameter hammer bit in the horizontal direction at the tunnel ***,the significant weight and uni-directional rotation of the rod head,as well as variables such as geological characteristics,machine conditions,and inexperienced operators result in significant deviation from the target borehole alignment that hinders the vibration-dampening effect of the uncharged ***,since there is no method to verify the alignment of the boreholes until main tunnel construction,borehole misalignment is often not discovered until weeks after construction,which requires tunnel construction to cease until the equipment can be remobilized and an additional borehole be created,causing significant delays and increased costs for the entire tunnel *** this study,the borehole alignment tracking and ground exploration system(BGS)is developed to predict and monitor the quality and alignment of boreholes for cut blasting methods such as the LLB methods immediately after *** BGS was subsequently tested at a subway construction site to evaluate its performance in the *** measurements yielded by the BGS were compared with manually measured boring positions at every 5 m along the *** the BGS showed a maximum deviation of approximately 12.at a local point where the hole surface was relatively rough,the accuracy for the final boring position was approximately 97%,demonstrating excellent precision of the alignment tracking *** BGS demonstrates excellent performance in predicting ground conditions and the boring quality of a cut hole immediately after drilling,and shows promise in various other applications for monitoring borehole alignment.

关键词： Tunnel blasting LLB method Drilling deviation Vertical sagging Horizontal alignment tracking BGS

Consistency of Tropospheric Water Vapor between Reanalyses and Himawari-8/AHI Measurements over East Asia

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Advances in Atmospheric Sciences 2024年第1期41卷 19-38页

作者： Di DI Jun LI Yunheng XUE min min Bo LI zhenglong LI Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Key Laboratory for Aerosol-Cloud-Precipitation China Meteorological AdministrationSchool of Atmospheric PhysicsNanjing University of Information Science and TechnologyNanjing 210044China FYSIC National Satellite Meteorological CenterChina Meteorological AdministrationBeijing 100081China Chengdu University of Information Science and Technology Chengdu 610225China School of Atmospheric Sciences and Guangdong Province Key laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University and Southern Laboratory of Ocean Science and EngineeringZhuhai 519082China Cooperative Institute for Meteorological Satellite Studies University of Wisconsin–MadisonMadison WI 53706WisconsinUSA Wuxi University Wuxi 214105China

High spatiotemporal resolution radiances from the advanced imagers onboard the new generation of geostationary weather satellites provide a unique opportunity to evaluate the abilities of various reanalysis datasets to depict multilayer tropospheric water vapor(WV),thereby enhancing our understanding of the deficiencies of WV in reanalysis *** on daily measurements from the Advanced Himawari Imager(AHI)onboard the Himawari-8 satellite in 2.16,the bias features of multilayer WV from six reanalysis datasets over East Asia are thoroughly *** assessments show that wet biases exist in the upper troposphere in all six reanalysis datasets;in particular,these biases are much larger in ***,we find better depictions of WV in the middle troposphere than in the upper *** accuracy of WV in the ERA5 dataset is the highest,in terms of the bias magnitude,dispersion,and pattern *** characteristics of the WV bias over the Tibetan Plateau are significantly different from those over other parts of East *** addition,the reanalysis datasets all capture the shift of the subtropical high very well,with ERA5 performing better overall.

关键词： AHI reanalysis dataset multilayer water vapor assessment radiative transfer model

A New Class of Strong Orthogonal Arrays of Strength Three

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Journal of Systems Science & Complexity 2024年第3期37卷 1233-1250页

作者： WANG Chunyan LIU min-Qian YANG Jinyu Center for Applied Statistics and School of Statistics Renmin University of ChinaBeijing 100872China School of Statistics and Data Science LPMC&KLMDASRNankai UniversityTianjin 300071China

Strong orthogonal arrays(SOAs) were recently introduced and studied as a class of spacefilling designs for computer experiments. To surely realize better space-filling properties, SOAs of strength three or higher are desirable. In addition, orthogonality is also an important property for designs of computer experiments, because it guarantees that the estimates of the main effects are uncorrelated. This paper first provides a systematic study on the construction of(nearly) orthogonal strength-three SOAs with better space-filling properties. The newly proposed strength-three SOAs enjoy almost the same space-filling properties of strength-four SOAs, and can accommodate much more columns than the latter. Moreover, they are(nearly) orthogonal and flexible in run sizes. The construction methods are straightforward to implement, and their theoretical supports are well established. In addition to the theoretical results, many designs are tabulated for practical needs.

关键词： Computer experiment orthogonality space-filling property strong orthogonal array

Particle effects on the hydrodynamics in slurry bubble column reactors:A review from multiscale mechanisms Author links open overlay panel

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Particuology 2024年第8期91卷 176-189页

作者： min An Jingqi Gao Tiankuo Wang Xiangnan Li National Supercomputing Center in zhengzhou Zhengzhou UniversityZhengzhou450001China School of Chemical Engineering and New Energy Xiamen University MalaysiaSepangSelangor43900Malaysia School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang453007China

Particles can appear as catalyst,reactant or product in various gas-liquid-solid three-phase production *** bubble column reactors(SBCRs),as a kind of three-phase reactors,are preferred for phase contacting and ***,literature studies concerning the effects of particles on the hydrodynamics of SBCRs are manifold and inconsistent in ***,the multiscale interactions between particles,turbulent eddies and bubbles determine the reactor *** review focuses on revealing the particle effects in SBCRs from the perspective of multiscale *** hydrodynamic changes due to particle effects in literature are *** parameters,including the Stokes number,the solid-to-liquid density ratio,the ratio of particle and liquid characteristic lengths,the contact angle and the particle volume fraction are adopted to evaluate the characteristics of gas-liquid-solid *** relationships between particle influencing mechanisms and these parameters are analyzed and *** experimental results are explained by different ranges of these dimensionless ***,particle effects at the mesoscale and microscale,such as the influence on the bubble dynamics and the pivoting effect on the turbulence energy spectrum,are ***,progress in modeling the SBCRs with consideration of particles effects using the Euler method are *** review aims to improve the overall understanding of the complex hydrodynamics in the SBCRs.

关键词： Slurry bubble column reactors Particle effects Turbulence characteristics Bubble dynamics CFD

Vibration Control of A Flexible Marine Riser System Subject to Input Dead zone and Extraneous Disturbances

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China Ocean Engineering 2024年第2期38卷 271-284页

作者： zHOU Li WANG Guo-rong WAN min School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China Energy Equipment Institute Southwest Petroleum UniversityChengdu 610500China National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China

An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental *** control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control ***,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each *** direction interference observers are designed to track the timevarying boundary *** this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead *** addition,the stability of the closed-loop system is proven by Lyapunov stability *** the system states are bounded,and the vibration offset of the riser converges to a small area of the initial ***,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.

关键词： adaptive backstepping control disturbance observer flexible marine riser input dead zone vibration control

An Approximation Algorithm Based on Seeding Algorithm for Fuzzy k-Means Problem with Penalties

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Journal of the Operations Research Society of China 2024年第2期12卷 387-409页

作者： Wen-zhao Liu min Li School of Mathematics and Statistics Shandong Normal UniversityJinan 250014ShandongChina

As a classic NP-hard problem in machine learning and computational geometry,the k-means problem aims to partition the given dataset into k clusters according to the minimal squared Euclidean *** from k-means problem and most of its variants,fuzzy k-means problem belongs to the soft clustering problem,where each given data point has relationship to every center *** to fuzzy k-means problem,fuzzy k-means problem with penalties allows that some data points need not be clustered instead of being paid *** this paper,we propose an O(αk In k)-approximation algorithm based on seeding algorithm for fuzzy k-means problem with penalties,whereαinvolves the ratio of the maximal penalty value to the minimal ***,we implement numerical experiments to show the effectiveness of our algorithm.

关键词： Approximation algorithm Seeding algorithm Fuzzy k-means problem with penalties

Weighted Forwarding in Graph Convolution Networks for Recommendation Information Systems

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Computers, Materials & Continua 2024年第2期78卷 1897-1914页

作者： Sang-min Lee Namgi Kim Department of Computer Science Kyonggi UniversitySuwonKorea

Recommendation Information Systems(RIS)are pivotal in helping users in swiftly locating desired content from the vast amount of information available on the *** Convolution Network(GCN)algorithms have been employed to implement the RIS ***,the GCN algorithm faces limitations in terms of performance enhancement owing to the due to the embedding value-vanishing problem that occurs during the learning *** address this issue,we propose a Weighted Forwarding method using the GCN(WF-GCN)*** proposed method involves multiplying the embedding results with different weights for each hop layer during graph *** applying the WF-GCN algorithm,which adjusts weights for each hop layer before forwarding to the next,nodes with many neighbors achieve higher embedding *** approach facilitates the learning of more hop layers within the GCN *** efficacy of the WF-GCN was demonstrated through its application to various *** the MovieLens dataset,the implementation of WF-GCN in LightGCN resulted in significant performance improvements,with recall and NDCG increasing by up to+163.64%and+132.04%,***,in the *** dataset,LightGCN using WF-GCN enhanced with WF-GCN showed substantial improvements,with the recall and NDCG metrics rising by up to+174.40%and+169.95%,***,the application of WF-GCN to Self-supervised Graph Learning(SGL)and Simple Graph Contrastive Learning(SimGCL)also demonstrated notable enhancements in both recall and NDCG across these datasets.

关键词： Deep learning graph neural network graph convolution network graph convolution network model learning method recommender information systems

One-pot synthesis of a giant twisted double-layer chiral macrocycle via [4+8] imine condensation and its X-ray structure

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Chinese Chemical Letters 2024年第10期35卷 241-243页

作者： Yu Pang min Wang Ning-Hua Yang min Xue Yong Yang School of Science Department of PhysicsKey Laboratory of Optical Field Manipulation of Zhejiang ProvinceZhejiang Sci-Tech UniversityHangzhou 310018China School of Chemistry and Chemical Engineering Key Laboratory of Surface&Interface Science of Polymer Materials of Zhejiang ProvinceZhejiang Sci-Tech UniversityHangzhou310018China

Trifluoroacetic acid(TFA)catalyzed condensation reaction between tetraaminooxacalix[4]arene and N-alkylcarbazole-3,6-dicarbaldehyde in CH_(2.Cl2.fforded a single product in 87%–89%***-defined yet undissolvable1H NMR spectra suggested formation of robust and discrete structures in solution.X-ray single crystal analysis further revealed a giant twisted double-layer chiral macrocycle in the solid state,which was formed from[4+8]condensation of the two reactants via 16 imine *** calculations discovered that only the[4+8]twisted product is thermodynamically favorable,which accounts for its highly selective and efficient formation out of a library of many other combinations.

关键词： One-pot synthesis Oxacalixarene Dynamic covalent chemistry Chiral macrocycle X-ray single crystal

Physiological and pathological functions of circular RNAs in the nervous system

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Neural Regeneration Research 2024年第2期19卷 342-349页

作者： min zhou Shi Li Chuan Huang School of Life Sciences Chongqing UniversityChongqingChina

Circular RNAs(circRNAs)are a class of covalently closed single-stranded RNAs that are expressed during the development of specific cells and *** play crucial roles in physiological and pathological processes by sponging microRNAs,modulating gene transcription,controlling the activity of certain RNA-binding proteins,and producing functional peptides.A key focus of research at present is the functionality of circRNAs in the nervous system and several advances have emerged over the last 2.***,the precise role of circRNAs in the nervous system has yet to be comprehensively *** this review,we first summarize the recently described roles of circRNAs in brain development,maturity,and ***,we focus on the involvement of circRNAs in various diseases of the central nervous system,such as brain cancer,chronic neurodegenerative diseases,acute injuries of the nervous system,and neuropathic pain.A better understanding of the functionality of circRNAs will help us to develop potential diagnostic,prognostic,and therapeutic strategies to treat diseases of the nervous system.

关键词： Alzheimer’s disease amyotrophic lateral sclerosis brain development circRNAs neuropathic pain Parkinson’s disease