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Effects of freeze-thaw cycle on engineering properties of loess used as road fills in seasonally frozen ground regions,North China

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Journal of Mountain Science 2017年第2期14卷 356-368页

作者： LI Guo-yu MA Wei MU yan-hu WANG Fei FAN Shan-zhi wu ya-hu State Key Laboratory of Frozen Soil Engineering Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of SciencesLanzhou 730000China

Compacted loess is widely used as fills of road embankments in loess regions of northern ***, densely-compacted loess can satisfy the requirements of embankment strength and postconstruction deformation. However, uneven subsidence, pavement cracks and other related damages can affect the integrity of loess subgrade after several years of operation,and even cause some hazards, especially in North China, where the strong freeze-thaw erosion occurs. In this study, cyclic freeze-thaw tests for both densely and loosely compacted loess samples were performed to determine the variation in engineering properties such as volume, void ratio, collapsible settlement,microstructure, and the related mechanisms were addressed. The experimental results showed that an obvious water migration and redistribution occurred within the samples during freeze-thaw cycles. Ice lenses and fissures could be identified in the upper frozen layers of the samples. After freeze-thaw cycles,the dry densities of the upper layers of samples changed significantly due to strong freeze-thaw erosion. The dry densities decreased for the dense sample and increased for the loose sample. It can be found that dense samples become loose, while loose samples became dense with the increasing number of freeze-thaw cycles. Their related void ratios changed reversely. Both void ratios tended to fall into a certain range, which verified the concept of a residual void ratio proposed by Viklander. The loosening process of densely compacted samples involves the formation of large pores, volume increase and density reduction as well as the related changes in mechanical properties because freeze-thaw cycles may be important contribution to problems of loess road *** effects of freeze-thaw cycles, therefore,should be taken into account in selecting loess parameters for the stability evaluation of road embankment in seasonally frozen ground regions.

关键词： Loess Freeze-thaw cycle Frost heave Thaw settlement Road engineering

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BSIN: A Behavior Schema of Information Networks Based on Approximate Bisimulation

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Tsinghua Science and Technology 2024年第4期29卷 1092-1104页

作者： wujie hu Jinzhao wu School of Electrical Engineering Guangxi UniversityNanning 530004China

Information networks are becoming increasingly important in practice. However, their escalating complexity is gradually impeding the efficiency of data mining. A novel network schema called the Behavior Schema of Information Networks (BSIN) is proposed to address this issue. This work defines the behavior of nodes as connected paths in BSIN, proposes a novel function distinguish behavior differences, and introduces approximate bisimulation into the acquisition of quotient sets for node types. The major highlight of BSIN is its ability to directly obtain a high-efficiency network on the basis of approximate bisimulation, rather than reducing the existing information network. It provides an effective representation of information networks, and the resulting novel network has a simple structure that more efficiently expresses semantic information than current network representations. The theoretical analysis of the connected paths between the original and the obtained networks demonstrates that errors are controllable;and semantic information is approximately retained. Case studies show that BSIN yields a simple network and is highly cost-effective.

关键词： data mining information network approximate bisimulation controllable error

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Effects of different orthokeratology lens designs on slowing axial length elongation in children with myopia

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International Journal of Ophthalmology(English edition) 2024年第10期17卷 1843-1849页

作者： Hai-Long Ni Xiang Chen Du-ya Chen Pei-Ke hu Zhi-Yi wu Eye Center the Second Affiliated Hospital of Zhejiang University School of MedicineHangzhou 310009Zhejiang ProvinceChina

AIM:To elucidate whether differences exist in the impact on retarding the elongation of axial length(AL)among children with myopia when utilizing orthokeratology(ortho-k)lenses employing the corneal refractive therapy(CRT)design versus those employing the vision shaping treatment(VST)***:This retrospective clinical trial aimed to collect and analyze AL data from individuals who wore ortho-k lenses for three years.A total of 654 subjects were enrolled and prescribed one of the three specific brands of ortho-k lenses:CRT,Euclid,and *** study’s primary focus was to compare the rates of AL elongation and myopic progression across these three brands of ortho-k ***:In the 3-year follow-up,the AL elongation exhibited variations of 0.73±0.36 mm in the CRT lens group,0.59±0.37 mm in the Euclid lens group,and 0.63±0.38 mm in the Mouldway lens group.A noteworthy disparity emerged between the CRT and Mouldway groups(P<0.01),as well as between the CRT and Euclid groups(P<0.001).Additionally,it was observed that 32.1%of participants who wore CRT lenses experienced a decelerated progression of myopia,in contrast to 47.2%in the Euclid group and 44.4%in the Mouldway *** analyses revealed a statistically significant distinction between the CRT and Euclid groups(P<0.01),and similarly,the CRT group demonstrated a statistically significant difference when compared to the Mouldway group(P<0.05).CONCLUSION:Ortho-k lenses represent a pragmatic strategy for mitigating the advancement of *** contradistinction to ortho-k lenses utilizing the CRT design,those employing the VST design exhibited a more favorable impact regarding retarding AL elongation.

关键词： myopia orthokeratology design axial length

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Optimization of jamming formation of USV offboard active decoy clusters based on an improved PSO algorithm

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Defence Technology（防务技术） 2024年第2期32卷 529-540页

作者： Zhaodong wu yasong Luo Shengliang hu College of Weapons Engineering PLA Naval University of EngineeringWuhan430033China

Offboard active decoys(OADs)can effectively jam monopulse ***,for missiles approaching from a particular direction and distance,the OAD should be placed at a specific location,posing high requirements for timing and *** improve the response speed and jamming effect,a cluster of OADs based on an unmanned surface vehicle(USV)is *** formation of the cluster determines the effectiveness of ***,based on the mechanism of OAD jamming,critical conditions are identified,and a method for assessing the jamming effect is ***,for the optimization of the cluster formation,a mathematical model is built,and a multi-tribe adaptive particle swarm optimization algorithm based on mutation strategy and Metropolis criterion(3M-APSO)is ***,the formation optimization problem is solved and analyzed using the 3M-APSO algorithm under specific *** results show that the improved algorithm has a faster convergence rate and superior performance as compared to the standard Adaptive-PSO *** with a single OAD,the optimal formation of USV-OAD cluster effectively fills the blind area and maximizes the use of jamming resources.

关键词： Electronic countermeasure Offboard active decoy USV cluster Jamming formation optimization Improved PSO algorithm

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Two-layer autonomous intelligence dynamic trajectory planning method based on shield-tunnel ring-geology interactions

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Underground Space 2024年第6期19卷 227-250页

作者： Min hu Bingjian wu huiming wu Liefeng Pei SILC Business School Shanghai UniversityShanghai 201800China Shu-SUCG Research Centre for Building Industrialization Shanghai 201800China Shanghai Tunnel Engineering Co. Ltd.Shanghai 200032China

To solve the problem that current attitude planning methods do not fully consider the interaction and constraints among the shield,segmental tunnel ring,and geology,and cannot adapt to the changes in the actual engineering environment,or provide feasible long-term and short-term attitude planning,this paper proposes autonomous intelligent dynamic trajectory planning(AI-DTP)to provide tunnel ring and centimeter-layer planning targets for a self-driving shield to meet long-term accuracy and short-term ***-DTP introduces the Frenet coordinate system to solve the problem of inconsistent spatial representation of tunnel data,segmental tunnel ring location,and surrounding geological conditions,designs the long short-term memory attitude prediction model to accurately predict shield attitude change trend based on shield,tunnel,and geology,and uses a heuristic algorithm for trajectory ***-DTP provides ring-layer and centimeter-layer planning objectives that meet the needs of long-term accuracy and short-term correction of shield attitude *** the Hangzhou-Shaoxing Intercity Railroad Tunnel Project in China,the‘‘Zhiyu”shield equipped with the AI-DTP system was faster and more accurate than the manually controlled shield,with a smoother process and better quality of the completed tunnel.

关键词： Shield tunnel Trajectory planning Attitude control Self-driving Machine learning

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Precise construction of RuPt dual single-atomic sites to optimize oxygen electrocatalytic behaviors for high-performance Zn-air batteries

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Journal of Energy Chemistry 2024年第10期97卷 520-528,I0011页

作者： Xiaolin hu Zhenkun wu Chaohe Xu School of Science Chongqing Key Laboratory of New Energy Storage Materials and DevicesChongqing University of TechnologyChongqing 400054China School of Chemistry and Engineering Chongqing UniversityChongqing 400044China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

The development of redox bifunctional electrocatalysts with high performance,low cost,and long lifetimes is essential for achieving clean energy *** study proposed an atom capture strategy for anchoring dual single atoms(DSAs)in a zinc-zeolitic imidazolate framework(Zn-ZIF),followed by calcination under an N_(2) atmosphere to synthesize ruthenium-platinum DSAs supported on a nitrogendoped carbon substrate(RuPt DSAs-NC).Theoretical calculations showed that the degree of Ru 5dxz-~*O 2p_x orbital hybridization was high when^(*)O was adsorbed at the Ru site,indicating enhanced covalent hybridization of metal sites and oxygen ligands,which benefited the adsorption of intermediate *** presence of the RuPtN_6 active center optimized the absorption-desorption behavior of intermediates,improving the electrocatalytic performance of the oxygen reduction reaction(ORR)and the oxygen evolution reaction(DER),RuPt DSAs-NC exhibited a 0.87 V high half-wave potential and a 268 mV low overpotential at 10 mA cm^(-2)in an alkaline ***,rechargeable zinc-air batteries(ZABs)achieved a peak power density of 171 MW cm^(-2).The RuPt DSAs-NC demonstrated long-term cycling for up to 500 h with superior round-trip *** study provided an effective structural design strategy to construct DSAs active sites for enhanced electrocata lytic performance.

关键词： Dual single atoms catalysts Atom capture Oxygen reduction reaction Oxygen evolution reaction Rechargeable Zn-air batteries

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Self-separation ionic liquid catalyst for the highly effective conversion of H2S by α,β-unsaturated carboxylate esters under mild conditions

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Green Energy & Environment 2024年第9期9卷 1440-1448页

作者： Wenjie Xiong Xiaomin Zhang Xingbang hu Youting wu Key Laboratory of Mesoscopic Chemistry of MOE School of Chemistry and Chemical Engineering Nanjing University The Institute of Green Chemistry and Engineering School of Chemistry and Chemical Engineering Nanjing University

The deep-processing utility of pure hydrogen sulfide （H2S） is a significant direction in natural gas chemical ***,a brand-new strategy of H2S conversion by a,β-unsaturated carboxylate esters into thiols or thioethers using task-specific carboxylate ionic liquids （ILs） as catalyst has been developed,firstly accomplishing the phase separation of product and catalyst without introducing the third *** can be considered as a cascade reaction in which the product selectivity can be controlled by adjusting the molar ratio of H2S to a,β-unsaturated carboxylate ***,the effects of ILs with different anions and cations,intermittent feeding operations,as well as pressure-time kinetic behaviors on cascade reaction were ***,the proposed interaction mechanism of H2S conversion using butyl acrylate catalyzed by[Emim][Ac]was revealed by DFT-based theoretical *** approach enables the self-phase separation promotion of catalyst and product and achieves 99%quantitative conversion under mild conditions in the absence of solvent,making the entire process ecologically ***-efficiency reaction activity can still be maintained after ten cycles of the ***,the good results,combined with its simplicity of operation and the high recyclability of the catalyst,make this green method environmentally friendly and *** is anticipated that this self-separation method mediated by task-specific ILs will provide a feasible strategy for H2S utilization,which will guide its application on an industrial scale.

关键词： Ionic liquid Cascade reaction Self-separation H 2 S conversion Catalysis

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Capillary Property of Entangled Porous Metallic Wire materials and Its Application in Fluid Buffers:Theoretical Analysis and Experimental Study

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Defence Technology（防务技术） 2024年第1期31卷 400-416页

作者： Yu Tang Yiwan wu hu Cheng Rong Liu Engineering Research Center for Metal Rubber School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou 350156China AECC Guizhou Liyang Aviation Power Co. LTDGuiyang 550014China College of Computer and Information Sciences Fujian Agriculture and Forestry UniversityFuzhou 350156China

Strong impact does serious harm to the military industries so it is necessary to choose reasonable cushioning material and design effective buffers to prevent the impact of *** on the capillary property entangled porous metallic wire materials(EPMWM),this paper designed a composite buffer which uses EPMWM and viscous fluid as cushioning materials under the low-speed impact of the recoil force device of weapon equipment(such as artillery,mortar,etc.).Combined with the capillary model,porosity,hydraulic diameter,maximum pore diameter and pore distribution were used to characterize the pore structure characteristics of *** calculation model of the damping force of the composite buffer was *** low-speed impact test of the composite buffer was *** parameters of the buffer under low-speed impact were identified according to the model,and the nonlinear model of damping force was *** test results show that the composite buffer with EPMWM and viscous fluid can absorb the impact energy from the recoil movement effectively,and provide a new method for the buffer design of weapon equipment(such as artillery,mortar,etc.).

关键词： Entangled porous metallic wire materials Capillary property Viscousfluid Low-speed impact Damping force

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Slippery hydrogel with desiccation-tolerant‘skin’for high-precision additive manufacturing

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International Journal of Extreme Manufacturing 2024年第2期6卷 486-500页

作者： Desheng Liu Pan Jiang Yue hu yaozhong Lu Yixian Wang Jiayu wu Danli hu Tao wu Xiaolong Wang State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000People’s Republic of China CAS Key Laboratory of Chemistry of Northwestern Plant Resources Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000People’s Republic of China Shandong Laboratory of Advanced Materials and Green Manufacturing at yantai Yantai Zhongke Research Institute of Advanced Materials and Green Chemical EngineeringYantai 264006People’s Republic of China Key Laboratory of Materials-Oriented Chemical Engineering of Xinjiang Uygur Autonomous Region School of Chemistry and Chemical EngineeringShihezi UniversityShihezi 832003People’s Republic of China

Hydrogels inevitably undergo dehydration,structural collapse,and shrinkage deformation due to the uninterrupted evaporation in the atmosphere,thereby losing their flexibility,slipperiness,and manufacturing ***,we propose a novel bioinspired strategy to construct a spontaneously formed‘skin’on the slippery hydrogels by incorporating biological stress metabolites trehalose into the hydrogel network,which can generate robust hydrogen bonding interactions to restrain water *** contents of trehalose in hydrogel matrix can also regulate the desiccation-tolerance,mechanical properties,and lubricating performance of slippery hydrogels in a wide *** vat photopolymerization three-dimensional printing and trehalose-modified slippery hydrogels enables to achieve the structural hydrogels with high resolution,shape fidelity,and sophisticated architectures,instead of structural collapse and shrinkage deformation caused by *** thus,this proposed functional hydrogel adapts to manufacture large-scale hydrogels with sophisticated architectures in a long-term *** a proof-of-concept demonstration,a high-precision and sophisticated slippery hydrogel vascular phantom was easily fabricated to imitate guidewire ***,the proposed protocol is universally applicable to diverse types of hydrogel *** strategy opens up a versatile methodology to fabricate dry-resistant slippery hydrogel for functional structures and devices,expanding their high-precision processing and broad applications in the atmosphere.

关键词： slippery hydrogel trehalose desiccation tolerance vat photopolymerization 3D printing hydrogen bonding

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Lake microbiome composition determines community adaptability to warming perturbations

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Ecological Processes 2024年第2期13卷 177-191页

作者： Xiaotong wu Qixing Zhou hui Zeng Xiangang hu Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education) Carbon Neutrality Interdisciplinary Science Centre/College of Environmental Science and Engineering Nankai University

Background Microbial communities are crucial for ecosystems. A central goal of microbial ecological research is to simplify the biodiversity in natural environments and quantify the functional roles to explore how the ecosystems respond under different environmental conditions. However, the research on the stability and dynamics of lake microbes in response to repeated warming stress is *** To exclude confounding environmental factors, we conducted a 20-day repeated warming simulation experiment to examine the composition and function dynamics of lake microbial *** Experimental warming significantly altered the community structure of bacteria instead of fungi. Microbial community structure, together with microbial biomass, jointly regulated the function of microbial communities. The plummeting of aerobic denitrifiers Pseudomonadaceae decreased by 99%(P hus determining lake microbial communities' adaptability to heat stress. This study extended our insights on the lake microbial community response and adaptability under warming drivers.

关键词： Temperature Environmental stress Bacteria Fungi Freshwater ecosystem

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