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A Yb optical clock with a lattice power enhancement cavity

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Chinese Physics B 2024年第3期33卷 70-74页

作者：王春云姚远师浩森于洪浮马龙生蒋燕义 state Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200062China

We construct a power enhancement cavity to form an optical lattice in an ytterbium optical *** is demonstrated that the intra-cavity lattice power can be increased by about 45 times,and the trap depth can be as large as 1400Er when laser light with a power of only 0.6 W incident to the lattice *** high trap depths are the key to accurate evaluation of the lattice-induced light shift with an uncertainty down to~1×*** probing the ytterbium atoms trapped in the power-enhanced optical lattice,we obtain a 4.3 Hz-linewidth Rabi spectrum,which is then used to feedback to the clock laser for the close loop operation of the optical lattice *** evaluate the density shift of the Yb optical lattice clock based on interleaving measurements,which is-0.46(62)*** result is smaller compared to the density shift of our first Yb optical clock without lattice power enhancement cavity mainly due to a larger lattice diameter of 344μm.

关键词： optical atomic clock optical lattice optical cavity Stark shift

Human-Machine Shared Lateral Control Strategy for Intelligent Vehicles Based on Human Driver Risk Perception Reliability

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Automotive Innovation 2024年第1期7卷 102-120页

作者： Dongjian Song Bing Zhu Jian Zhao Jiayi Han state Key Laboratory of Automotive Simulation and Control Jilin UniversityChangchun 130022China

Intelligent vehicle(Ⅳ)technology has developed rapidly in recent ***,achieving fully unmanned driving still presents numerous challenges,which means that human drivers will continue to play a vital role in vehicle operation for the foreseeable ***-machine shared driving,involving cooperation between a human driver and an automated driving system(AVS),has been widely regarded as a necessary stage for the development of *** onⅣdriving safety,this study proposed a human-machine shared lateral control strategy(HSLCS)based on the reliability of driver risk *** HSLCS starts by identifying the effective areas of driver risk perception based on eye *** establishes an anisotropic driving risk field,which serves as the foundation for the AVS to assess risk *** upon the cumulative and diminishing effects of risk perception,the proposed approach leverages the driver's risk perception effective area and converts the risk field into a representation aligned with the driver's ***,it quantifies the reliability of the driver's risk perception by using area-matching ***,based on the driver’s risk perception reliability and dif-ferences in lateral driving operation between the human driver and the AVS,the dynamic distribution of driving authority is achieved through a fuzzy rule-based system,and the human-machine shared lateral control is completed by using model predictive *** HSLCS was tested across various scenarios on a driver-in-the-loop test *** results show that the HSLCS can realize the synergy and complementarity of human and machine intelligence,effectively ensuring the safety ofⅣoperation.

关键词： Intelligent vehicle Human-machine shared driving Risk perception Driving authority distribution

Prediction of ball-on-plate friction and wear by ANN with data-driven optimization

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Friction 2024年第6期12卷 1235-1249页

作者： Alexander KOVALEV Yu TIAN Yonggang MENG state Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China

For training artificial neural network(ANN),big data either generated by machine or measured from experiments are used as input to"learn"the unspecified functions defining the *** experimental data are fed directly into the optimizer allowing training to be performed according to a predefined loss *** predict sliding friction and wear at mixed lubrication conditions,in this study a specific ANN structure was so designed that deep learning algorithms and data-driven optimization models can be *** ball-on-plate friction and wear data were analyzed using the specific training procedure to optimize the weights and biases incorporated into the neural layers of the ANN,and only two independent experimental data sets were used during the ANN optimization *** the training procedure,the ANN is capable to predict the contact and hydrodynamic pressure by adapting the output data according to the tribological condition implemented in the optimization algorithm.

关键词： machine learning deep learning artificial neural network mixed lubrication

Synergistic effects of multiscale TiC and dual-phase structure on tensile properties of particle-reinforced steel

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Journal of Iron and Steel Research(International) 2024年第5期31卷 1232-1245页

作者： Ye Jia Xiang-tao Deng Qi Wang Cheng-ru Li Hao Wu Zhao-dong Wang state Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina

The conventional melting methods were used to obtain in situ TiC particle-reinforced dual-phase steel,followed by hot rolling and heat treatment *** aim was to investigate the effect of TiC particles on the fracture behavior of dual-phase steel at different annealing temperatures,by analyzing the microstructure and tensile behavior of the multiscale TiC particle-reinforced dual-phase *** results showed that TiC particles precipitated in the as-cast microstructure of dual-phase steel were distributed along the grain *** hot rolling,the grain boundary-like morphology of the micron-sized TiC particles was disrupted,and the particles became more refined and evenly distributed in the *** tensile tests revealed that the strength of the TiC particle-reinforced dual-phase steel increased with increasing martensite content,while the elongation *** results were similar to those of conventional *** addition of 1 vol.%multiscale TiC particles improved the strength of the dual-phase steel but did not affect elongation of the *** and holes were primarily concentrated around the TiC particles rather than at the interface of martensite and *** main causes of crack sprouting were TiC particle interface cracking and TiC particle internal ***,the study demonstrated the potential of multiscale TiC particle-reinforced dual-phase steel as a strong and tough *** refined distribution of TiC particles in the matrix improved the strength of the material without compromising its *** results also highlighted the importance of careful selection of reinforcement particles to avoid detrimental effects on the fracture behavior of the material.

关键词： TiC particle Dual-phase structure TiC-reinforced dual-phase steel Tension Fracture behavior

On a Formation of Singularities of Solutions to Soliton Equations Represented by L,A,B-triples

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Acta Mathematica Sinica,English Series 2024年第1期40卷 406-416页

作者： Iskander A.TAIMANOV Novosibirsk state university 630090 Novosibirskand Sobolev Institute of Mathematics630090 NovosibirskRussia

We discuss the mechanism of formation of singularities of solutions to the Novikov-Veselov,modified Novikov-Veselov,and Davey-Stewartson II(DSII)equations obtained by the Moutard type *** equations admit the L,A,B-triple presentation,the generalization of the L,Apairs for 2+1-soliton *** relate the blow-up of solutions to the non-conservation of the zero level of discrete spectrum of the *** also present a class of exact solutions,of the DSII system,which depend on two functional parameters,and show that all possible singularities of solutions to DSII equation obtained by the Moutard transformation are indeterminancies,i.e.,points when approaching which in different spatial directions the solution has different limits.

关键词： Soliton equation blow up Davey-Stewartson equation Moutard transformation

Scale-space effect and scale hybridization in image intelligent recognition of geological discontinuities on rock slopes

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1315-1336页

作者： Mingyang Wang Enzhi Wang Xiaoli Liu Congcong Wang state Key Laboratory of Hydro-science and Engineering Tsinghua UniversityBeijing100084China

Geological discontinuity(GD)plays a pivotal role in determining the catastrophic mechanical failure of jointed rock *** and efficient acquisition of GD networks is essential for characterizing and understanding the progressive damage mechanisms of slopes based on monitoring image *** by recent advances in computer vision,deep learning(DL)models have been widely utilized for image-based fracture *** multi-scale characteristics,image resolution and annotation quality of images will cause a scale-space effect(SSE)that makes features indistinguishable from noise,directly affecting the ***,this effect has not received adequate ***,we try to address this gap by collecting slope images at various proportional scales and constructing multi-scale datasets using image processing ***,we quantify the intensity of feature signals using metrics such as peak signal-to-noise ratio(PSNR)and structural similarity(SSIM).Combining these metrics with the scale-space theory,we investigate the influence of the SSE on the differentiation of multi-scale features and the accuracy of *** is found that augmenting the image's detail capacity does not always yield benefits for vision-based recognition *** light of these observations,we propose a scale hybridization approach based on the diffusion mechanism of scale-space *** results show that scale hybridization strengthens the tolerance of multi-scale feature recognition under complex environmental noise interference and significantly enhances the recognition accuracy of *** also facilitates the objective understanding,description and analysis of the rock behavior and stability of slopes from the perspective of image data.

关键词： Image processing Geological discontinuities Deep learning Multi-scale Scale-space theory Scale hybridization

Low crude protein formulation with supplemental amino acids for its impacts on intestinal health and growth performance of growing-finishing pigs

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Journal of Animal Science and Biotechnology 2024年第4期15卷 1590-1606页

作者： Marcos Elias Duarte Wanpuech Parnsen Shihai Zhang Marvio L.T.Abreu Sung Woo Kim Department of Animal Science North Carolina State UniversityRaleighNC 27695USA

Background Low crude protein(CP)formulations with supplemental amino acids(AA)are used to enhance intestinal health,reduce costs,minimize environmental impact,and maintain growth performance of ***,extensive reduction of dietary CP can compromise growth performance due to limited synthesis of non-essential AA and limited availability of bioactive compounds from protein supplements even when AA requirements are ***,implementing a low CP formulation can increase the net energy(NE)content in feeds causing excessive fat *** supplementation of functional AA,coupled with low CP formulation could further enhance intestinal health and glucose metabolism,improving nitrogen utilization,and growth *** experiments were conducted to evaluate the effects of low CP formulations with supplemental AA on the intestinal health and growth performance of growing-finishing *** In Exp.1,90 pigs(19.7±1.1 kg,45 barrows and 45 gilts)were assigned to 3 treatments:CON(18.0%CP,supplementing Lys,Met,and Thr),LCP(16.0%CP,supplementing Lys,Met,Thr,Trp,and Val),and LCPT(16.1%CP,LCP+0.05%SID Trp).In Exp.2,72 pigs(34.2±4.2 kg BW)were assigned to 3 treatments:CON(17.7%CP,meeting the requirements of Lys,Met,Thr,and Trp);LCP(15.0%CP,meeting Lys,Thr,Trp,Met,Val,Ile,and Phe);and VLCP(12.8%CP,meeting Lys,Thr,Trp,Met,Val,Ile,Phe,His,and Leu).In Exp.3,72 pigs(54.1±5.9 kg BW)were assigned to 3 treatments and fed experimental diets for 3 phases(grower 2,finishing 1,and finishing 2).Treatments were CON(18.0%,13.8%,12.7%CP for 3 phases;meeting Lys,Met,Thr,and Trp);LCP(13.5%,11.4%,10.4%CP for 3 phases;meeting Lys,Thr,Trp,Met,Val,Ile,and Phe);and LCPG(14.1%,12.8%,11.1%CP for 3 phases;LCP+Glu to match SID Glu with CON).All diets had 2.6 Mcal/kg *** In Exp.1,overall,the growth performance did not differ among *** LCPT increased(P<0.05)Claudin-1 expression in the duodenum and *** LCP and LCPT increased(P<0.05)CAT-1,4F2hc,and B0AT exp

关键词： Amino acids Growing-finishing pigs Growth performance Intestinal health Low crude protein formulation Net energy

In memoriam:Shizhu Wen(1932-2023)

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Friction 2024年第7期12卷 1341-1346页

作者： Jianbin LUO Yonggang MENG Yu TIAN state Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China

Professor Shizhu Wen,the winner of the 2015 Tribology Gold Medal,passed away due to illness on November 3,2023,at the age of *** was a professor of Tsinghua university,an academician of the Chinese Academy of Sciences,and the Honorary President of the Chinese Tribology Institute(CTI)from 1997 to *** Wen was born in 1932 in Jiangxi Province of China and graduated from Tsinghua university in 1955,where he was awarded the Outstanding Graduate Gold Medal and then remained as an assistant professor at the *** Wen was promoted to full professor in *** had undertaken tribology research at the Imperial College London in 1979 and *** 1985,he presided over the establishment of the state Key Laboratory of Tribology(SKLT)of Tsinghua university and served as the first director of the SKLT.

关键词： sided professor zhu

A reduced combustion mechanism of ammonia/diesel optimized with multi-objective genetic algorithm

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Defence Technology（防务技术） 2024年第4期34卷 187-200页

作者： Wanchen Sun Shaodian Lin Hao Zhang Liang Guo Wenpeng Zeng Genan Zhu Mengqi Jiang state Key Laboratory of Automotive Simulation and Control Jilin UniversityChangchun 130025China

For the deep understanding on combustion of ammonia/diesel,this study develops a reduced mechanism of ammonia/diesel with 227 species and 937 *** sub-mechanism on ammonia/interactions of N-based and C-based species(N—C)/NOx is optimized using the Non-dominated Sorting Genetic Algorithm II(NSGA-II)with 200 *** optimized mechanism(named as 937b)is validated against combustion characteristics of ammonia/methane(which is used to examine the accuracy of N—C interactions)and ammonia/diesel *** ignition delay times(IDTs),the laminar flame speeds and most of key intermediate species during the combustion of ammonia/methane blends can be accurately simulated by 937b under a wide range of *** for ammonia/diesel blends with various diesel energy fractions,reasonable predictions on the IDTs under pressures from 1.0 MPa to5.0 MPa as well as the laminar flame speeds are also achieved by *** particular,with regard to the IDT simulations of ammonia/diesel blends,937b makes progress in both aspects of overall accuracy and computational efficiency,compared to a detailed ammonia/diesel *** kinetic analysis reveals that the reaction pathway of ammonia during the combustion of ammonia/diesel blend mainly differs in the tendencies of oxygen additions to NH_2 and NH with different equivalence ratios.

关键词： Ammonia Diesel Combustion Kinetic mechanism Multi-objective optimization