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Chinese Chemical Letters 2019年第5期30卷 1075-1077页

作者： Haiqing Xiong long he Yun Zhang Jingpei Wang Xiangzhi Song Zhaoguang Yang College of Chemistry&Chemical Engineering Central South UniversityChangsha 410083China Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety Changsha 410083China

A ratiometric fluorescence probe,NClO,for the rapid and selective detection of HClO had been designed and synthesized based on a 1,8-naphthalimide *** NClO displayed a red emission(λmax=615 nm).In the presence of HClO,the solution of probe NClO gave off a strong green fluorescence(λem,max=520 nm)with a rapid response(within seconds).This probe had been applied to image HClO in living cells and zebra fish.

关键词： Fluorescent probe Hypochlorous acid Ratiometric Organism Large stokes shift

Towards an improved prediction of soil-freezing characteristic curve based on extreme gradient boosting model

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Geoscience Frontiers 2024年第6期15卷 229-243页

作者： Kai-Qi Li Hai-long he Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina College of Natural Resources and Environment Northwest A&F UniversityYangling 712100China Department of Soil Science University of ManitobaWinnipegManitobaR3T 2N2 Canada

As an essential property of frozen soils,change of unfrozen water content(UWC)with temperature,namely soil-freezing characteristic curve(SFCC),plays significant roles in numerous physical,hydraulic and mechanical processes in cold regions,including the heat and water transfer within soils and at the land–atmosphere interface,frost heave and thaw settlement,as well as the simulation of coupled thermo-hydro-mechanical *** various models have been proposed to estimate SFCC,their applicability remains limited due to their derivation from specific soil types,soil treatments,and test ***,this study proposes a novel data-driven model to predict the SFCC using an extreme Gradient Boosting(XGBoost)model.A systematic database for SFCC of frozen soils compiled from extensive experimental investigations via various testing methods was utilized to train the XGBoost *** predicted soil freezing characteristic curves(SFCC,UWC as a function of temperature)from the well-trained XGBoost model were compared with original experimental data and three conventional *** results demonstrate the superior performance of the proposed XGBoost model over the traditional models in predicting *** study provides valuable insights for future investigations regarding the SFCC of frozen soils.

关键词： Soil freezing characteristic curve(SFCC) Soil temperature Unfrozen water content XGBoost model Machine Learning Feature importance

An Improved Result for Positive Measure Reducibility of Quasi-periodic Linear Systems

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Acta Mathematica Sinica,English Series 2006年第1期22卷 77-86页

作者： Hai long he Jian Gong YOU Department of Mathcmatics Nanjing University Nanjing 210093 P. R. China

In this paper, by the KAM method, under weaker small denominator conditions and nondegeneracy conditions, we prove a positive measure reducibility for quasi-periodic linear systems close to constant： X = （A（λ）＋ F（ψ, λ））X, ψ=ωwhere the parameter λ∈ （a, b）, w is a fixed Diophantine vector, which is a generalization of jorba ＆ Simo＇s positive measure reducibility result.

关键词： Quasi-periodic Reducibility KAM Non-degeneracy

Gaze Estimation via a Differential Eyes’Appearances Network with a Reference Grid

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Engineering 2021年第6期7卷 777-786页

作者： Song Gu Lihui Wang long he Xianding he Jian Wang Chengdu Aeronautic Polytechnic Chengdu 610100China Department of Production Engineering KTH Royal Institute of TechnologyStockholm 10044Sweden

A person’s eye gaze can effectively express that person’s ***,gaze estimation is an important approach in intelligent manufacturing to analyze a person’s *** gaze estimation methods regress the direction of the gaze by analyzing images of the eyes,also known as eye ***,it is very difficult to construct a person-independent model that can estimate an accurate gaze direction for every person due to individual *** this paper,we hypothesize that the difference in the appearance of each of a person’s eyes is related to the difference in the corresponding gaze *** on this hypothesis,a differential eyes’appearances network(DEANet)is trained on public datasets to predict the gaze differences of pairwise eye patches belonging to the same *** proposed DEANet is based on a Siamese neural network(SNNet)framework which has two identical branches.A multi-stream architecture is fed into each branch of the *** branches of the DEANet that share the same weights extract the features of the patches;then the features are concatenated to obtain the difference of the gaze *** the differential gaze model is trained,a new person’s gaze direction can be estimated when a few calibrated eye patches for that person are *** personspecific calibrated eye patches are involved in the testing stage,the estimation accuracy is ***,the problem of requiring a large amount of data when training a person-specific model is effectively avoided.A reference grid strategy is also proposed in order to select a few references as some of the DEANet’s inputs directly based on the estimation values,further thereby improving the estimation *** on public datasets show that our proposed approach outperforms the state-of-theart methods.

关键词： Gaze estimation Differential gaze Siamese neural network Cross-person evaluations Human–robot collaboration

Tribological properties of laser cladding TiB_2 particles reinforced Ni-base alloy composite coatings on aluminum alloy

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Rare Metals 2015年第11期34卷 789-796页

作者： long he Ye-Fa Tan Xiao-long Wang Qi-Feng Jing Xiang Hong College of Field Engineering PLA University of Science and Technology

To improve the wear resistance of aluminum alloy frictional parts, Ti B2particles reinforced Ni-base alloy composite coatings were prepared on aluminum alloy 7005 by laser cladding. The microstructure and tribological properties of the composite coatings were investigated. The results show that the composite coating contains the phases of Ni Al, Ni3Al, Al3Ni2, TiB2, TiB, TiC, CrB, and *** microhardness is HV0.5855.8, which is 15.4 % higher than that of the Ni-base alloy coating and is 6.7 times as high as that of the aluminum alloy. The friction coefficients of the composite coatings are reduced by 6.8 %–21.6 % and 13.2 %–32.4 % compared with those of the Ni-base alloy coatings and the aluminum alloys, while the wear losses are 27.4 %–43.2 % less than those of the Ni-base alloy coatings and are only 16.5 %–32.7 % of those of the aluminum alloys at different loads. At the light loads ranging from 3 to 6 N, the calculated maximum contact stress is smaller than the elastic limit contact stress. The wear mechanism of the composite coatings is micro-cutting wear, but changes into multi-plastic deformation wear at 9 N due to the higher calculated maximum contact stress than the elastic limit contact stress. As the loads increase to 12 N, the calculated flash temperature rises to 332.1 °*** composite coating experiences multi-plastic deformation wear, micro-brittle fracture wear, and oxidative wear.

关键词： Ti B2 Ni-base alloy Laser cladding Composite coati

Test analysis of detection of damage to a complicated spatial model structure

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Acta Mechanica Sinica 2011年第3期27卷 399-405页

作者： long-he Xu Zhong-Xian Li Jia-Ru Qian School of Civil Engineering Beijing Jiaotong University 100044 Beijing China School of Civil Engineering Tianjin University 300072 Tianjin China Department of Civil Engineering Tsinghua University 100084 Beijing China

A two-stage damage detection approach is proposed and experimentally demonstrated on a complicated spatial model structure with a limited number of measurements. In the experiment,five known damage patterns,including 3 brace damage cases and 2 joint damage cases,were simulated by removing braces and weakening beam鈥揷olumn connections in the structure. The limited acceleration response data generated by hammer impact were used for system identification,and modal parameters were extracted by using the eigensystem realization algorithm. In the first stage,the possible damaged locations are determined by using the damage index and the characteristics of the analytical model itself,and the extent of damage for those substructures identified at stage I is estimated in the second stage by using a second-order eigen-sensitivity approximation method. The main contribution of this paper is to test the two-stage method by using the real dynamic data of a complicated spatial model structure with limited sensors. The analysis results indicate that the two-stage approach is ableto detect the location of both damage cases,only the severity of brace damage cases can be assessed,and the reasonable analytical model is critical for successful damage detection.

关键词： Damage detection. Complicated structure. Two-stage approach - Eigen-sensitivity analysis. Joint dam- age

Disorder driven superconductor-insulator transition in inhomogenous d-wave superconductor

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Science China(Physics,Mechanics & Astronomy) 2016年第1期59卷 86-91页

作者： Jian Sun long he Yang Yang Zhao Yun Song Department of Physics Beijing Normal University

We study the effect of disorder on the superconductor-insulator transition in an inhomogeneous d-wave superconductor using the kernel polynomial method. As the Bogoliubov-de Gennes equations of the two-dimensional square lattice are solved self-consistently for the cases with more than 100000 unit cells, it is possible to observe the spatial fluctuations of the superconducting order parameters at the nanoscale. We find that strong spatial fluctuation of the superconducting order parameters can be introduced by disorder, and some superconducting specific order parameters are even enhanced. Moreover, we find that some isolated superconducting "islands" can survive the strong disorder, giving a boson insulator with some localized Cooper pairs. Our numerical calculations predict the existence of two sequential transitions with the increasing disorder strength: a d-wave to s-wave superconductor transition, and then an s-wave superconductor to insulator transition. The possibility of the appearance of a metallic phase between the superconducting and insulating phases is excluded by performing the lattice-size scaling of the generalized inverse participation ratio. In addition, we also discuss the effect of disorder on the optical conductivity of the d-wave superconductors.

关键词： superconductor-insulator transition effect of disorder d-wave superconductor

Rotor airfoil aerodynamic design method and wind tunnel test verification

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Chinese Journal of Aeronautics 2020年第8期33卷 2123-2132页

作者： Weiguo ZHANG Junfeng SUN Liangquan WANG Jie WU long he School of Aeronautics Northwestern Polytechnical UniversityXi'an 710000China Computational Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang 621000China Low Speed Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang 621000China

Well-designed airfoil is very important for high-performance *** paper developed an efficient multi-objective and multi-constraint optimization design system for rotor airfoils based on RANS analysis,and verified the performance of the optimized *** CRA09-A as the baseline rotor airfoil,the CRA09-B optimized rotor airfoil was designed *** with the foundation of high-precision rotor airfoil stationary test technology,the CRA09-B and CRA09-A rotor airfoils were tested in the S3 MA high-speed wind tunnel of *** order to correct the aerodynamic data,a single parameter linear wall pressure method is used to consider the tunnel *** results indicate that multi-objective and multi-constraint optimization design method developed in this study is reliable,and that CRA09-B optimized airfoil provides better stationary performance than CRA09-A airfoil in terms of maximum lift coefficient and lift-to-drag ratio.

关键词： Airfoil design CRA09 airfoil Optimization method Rotor Wind tunnel test

Model study of the upper circulation in the Sulu Sea and its relation to the South China Sea circulation

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Acta Oceanologica Sinica 2008年第z1期27卷 119-128页

作者： CAI Shuqun he Yinghui long Xiaomin WANG Shengan Key Laboratory of Tropical Marine Environmental Dynamics South China Sea Institute of Oceanology Chinese Academy of Sci-ences Guangzhou 510301 China Key Laboratory of Tropical Marine Environmental Dynamics South China Sea Institute of Oceanology Chinese Academy of Sci-ences Guangzhou 510301 China Graduate School of the Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Tropical Marine Environmental Dynamics South China Sea Institute of Oceanology Chinese Academy of Sci-ences Guangzhou 510301 China Key Laboratory of Tropical Marine Environmental Dynamics South China Sea Institute of Oceanology Chinese Academy of Sci-ences Guangzhou 510301 China

According to the satellite remote sensing monthly mean sea surface temperature data from 1998 to 2002, it is shown that, the Sulu Sea is dominated by a cold eddy both in summer and winter. A coupled single-layer/two-layer model is employed here to study the summery and wintry characteristics and dynamic mechanism of the upper circulation in the Sulu Sea. According to the numerical experiments, it is found that, due to the local monsoon stress curl, the upper circulation in the Sulu Sea is dominated by a weak anticyclonic eddy in summer and a strong cyclonic eddy in winter. Once there is a large outflow via the Sibutu Passage flowing out of the Sulu Sea in summer, the upper circulation in the Sulu Sea may be dominated by a cyclonic eddy instead of the normal anticyclonic one. Moreover, in summer, the water exchange between the Sulu Sea and South China Sea via the Mindoro and Balabac Straits might have some effect on the separation position and strength of the northward western boundary current next to the Indo-China Peninsula in the southern South China Sea.

关键词： circulation monsoon numerical model Sulu Sea South China Sea

B-C-N Compounds with Mixed Hybridization of sp^(2)-Like and sp^(3)-Like Bonds

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Chinese Physics Letters 2012年第3期29卷 161-164页

作者： LUO Xiao-Guang he Ju-long Department of Electronics College of Information Technical ScienceNankai UniversityTianjin 300071 State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004

We perform first-principles calculations of the structural and electronic properties of hypothetical bc6-BC_(4)N and N-substituted bc6-BC4N,which are derived from a body-center-cubic carbon *** calculations show that the former is a semiconductor with an indirect band gap of 0.91 eV and the latter is *** calculated bond length,bond population,and charge density of N-substituted bc6-BC4N indicate that one C-N bond has been broken after N-substitution,which means that the structure contains a mixed hybridization of sp^(2)-like and sp^(3)-1ike *** the pressure above 100 GPa,the structure changes to a pure sp^(3)-like hybridization.

关键词： structure substituted bonds