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磁铁矿介导沉积物中菲的微生物降解机制

中国环境科学 2025年第1期45卷 208-222页

作者：王鸿洋尤佳晏再生江和龙叶华香哈尔滨师范大学地理科学学院黑龙江哈尔滨150025 中国科学院南京地理与湖泊研究所湖泊与流域水安全重点实验室江苏南京210008 中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室江苏南京210008 东南大学土木工程学院江苏南京210096

制备两种不同形态的磁铁矿(纳米Fe_(3)O_(4)和微米Fe_(3)O_(4)),对不同形态磁铁矿介导下沉积物中PAHs的生物降解影响进行了探究.在有氧条件下,纳米Fe_(3)O_(4)和微米Fe_(3)O_(4)未明显降低沉积物PAHs总含量.为进一步探究在不同氧化还原... 详细信息

制备两种不同形态的磁铁矿(纳米Fe_(3)O_(4)和微米Fe_(3)O_(4)),对不同形态磁铁矿介导下沉积物中PAHs的生物降解影响进行了探究.在有氧条件下,纳米Fe_(3)O_(4)和微米Fe_(3)O_(4)未明显降低沉积物PAHs总含量.为进一步探究在不同氧化还原条件下磁铁矿对PAHs的厌氧生物降解影响,以菲为目标污染物,通过富集和培养沉积物中的相关降解菌群落,在不同氧化还原条件下投加两种形态的磁铁矿进行培养实验,发现投加Fe_(3)O_(4)在一定程度上促进了菲的厌氧生物降解.在没有外加电子受体的条件下微米Fe_(3)O_(4)能显著促进菲的降解,而在硫酸盐或硝酸盐处理组中纳米Fe_(3)O_(4)对菲降解的促进效果更显著,菲降解速率常数是对照组的1.39倍.电子传递体系(ETS)活性结果表明,投加Fe_(3)O_(4)可以显著提高微生物呼吸活性.纳米Fe_(3)O_(4)处理组和微米Fe_(3)O_(4)处理组的ETS活性较对照组分别提高了441.7%~511.2%和113.8%~141.1%.微生物群落结构表明,投加Fe_(3)O_(4)增加了芳香化合物降解菌Hydrogenophaga及Ignavibacterium的丰度;相对于微米Fe_(3)O_(4),纳米Fe_(3)O_(4)提高了PAHs降解菌Achromobacter和Ensifer的丰度.另外,纳米Fe_(3)O_(4)可能通过释放更多的Fe(Ⅱ)和Fe(Ⅲ)来介导微生物间的电子转移.这些结果有助于深入理解磁铁矿在有机污染物生物降解过程中的重要作用,为污染沉积物修复提供了一种潜在的应用方法.

关键词：磁铁矿多环芳烃生物降解电子传递

基于注意力机制的高光谱图像降维在纸质文物霉斑识别的研究

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光谱学与光谱分析 2025年第1期45卷 246-255页

作者：汤斌贺渝龙唐欢龙邹荣王建旭谭博文覃丹罗希玲赵明富重庆理工大学重庆市光纤传感与光电检测重点实验室重庆400054 馆藏文物有害生物控制研究国家文物局重点科研基地(重庆中国三峡博物馆) 重庆400060

纸质文物作为文物传承的重要工具,用于记录不同时期人类历史及人文风貌,其在保存过程中极易受到霉菌等微生物的侵害。霉菌会加速纤维素的降解,在纸张表面生成霉斑,并且散落的孢子会随空气流动大范围传播,增加其他纸质文物发生霉变的风... 详细信息

纸质文物作为文物传承的重要工具,用于记录不同时期人类历史及人文风貌,其在保存过程中极易受到霉菌等微生物的侵害。霉菌会加速纤维素的降解,在纸张表面生成霉斑,并且散落的孢子会随空气流动大范围传播,增加其他纸质文物发生霉变的风险。因此,定期对纸质文物进行霉斑检测对了解纸质文物现状和纸质文物修复至关重要。高光谱成像技术是一种非接触性、非破坏性的检测技术,能同时获得空间数据和光谱数据,与计算机技术结合可以实现纸质文物的大批次实时无损检测。针对黑曲霉这一广泛出现的霉菌,提出一种基于注意力机制的高光谱数据降维方法,通过采集其高光谱数据,实现了高光谱冗余数据的自适应预处理。采集了来自重庆中国三峡博物馆提供的20份纸质文物黑曲霉霉斑样本,使用ENVI软件分析得出在413~855 nm波段范围内,黑曲霉霉斑感染区域和健康区域的平均光谱曲线,平均反射率差异明显;在855~1021 nm波段范围内,黑曲霉霉斑感染区域和墨迹区域的平均光谱曲线,平均反射率差异明显。文中将所提出方法与传统主成分分析和独立成分分析预处理方法分别处理原始高光谱数据,并将结果在经典U-Net、SegNet、DeepLabV3+和PSPNet四个语义分割网络上进行了对比。结果表明,该算法预处理的数据在U-Net和SegNet经典网络中有明显优势,相较于主成分分析法和独立成分分析法,霉斑识别精度取得了较大提升达到89.49%和88.46%,验证了本文所提出算法的有效性,为文物保护领域提供有效的支撑和新的思路。

关键词：高光谱数据预处理霉斑识别纸质文物注意力机制图像分割

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

草原人居系统:内涵特征、构建框架与发展方向

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中国工程科学 2025年第1期27卷 269-280页

作者：张鹏举王志强雷振东狄彦强荣丽华贺龙李佳何苗内蒙古工业大学建筑学院呼和浩特010051 西安建筑科技大学建筑学院西安710055 中国建筑科学研究院有限公司北京100013

草原人居环境建设事关国家生态安全、边疆民族地区稳定发展,需要构建人居环境系统,应对草原地区产业与生态平衡、发展与保护协同等方面的挑战。本文提出了草原人居系统概念,支持研究草原地区的人、自然环境、社会经济等因素叠加形成的... 详细信息

草原人居环境建设事关国家生态安全、边疆民族地区稳定发展,需要构建人居环境系统,应对草原地区产业与生态平衡、发展与保护协同等方面的挑战。本文提出了草原人居系统概念,支持研究草原地区的人、自然环境、社会经济等因素叠加形成的复杂系统;阐释了草原人居系统的内涵特征与发展现状,分析了草原人居系统建设面临的结构秩序有待重构、空间布局有待改善、适宜设计理论与方法缺乏、适宜低碳技术体系缺失等挑战;构建了涵盖要素提取、层级关联、系统互适3个核心方面的研究框架,提炼形成“三生—适洽”演化理论,倡导“融自然‒低建造‒承传统”草原人居营建的新范式。研究建议,推动草原牧区“生态‒生产‒生活”空间一体化发展,构建适应草原牧区“自然‒资源‒社会”的建筑设计理论与方法,建立适应当地严气候、弱经济、富资源背景的低碳牧区营建技术体系,推动新时期草原人居建设高质量发展。

关键词：草原人居系统导控要素层级结构 “三生”空间人居环境生态空间

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