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Stress-assisted corrosion mechanism of 3Ni steel by using gradient boosting decision tree machining learning method

International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1311-1321页

作者： Xiaojia Yang Jinghuan Jia Qing li Renzheng Zhu Jike Yang Zhiyong liu Xuequn cheng Xiaogang li Institute of Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China AECC Key Laboratory of Advanced Corrosion and Protection of Aeronautical Materials AECC Beijing Institute of Aeronautical MaterialsBeijing 100095China Shunde Innovation School University of Science and Technology BeijingFoshan 528399China

Traditional 3Ni weathering steel cannot completely meet the requirements for offshore engineering development,resulting in the design of novel 3Ni steel with the addition of microalloy elements such as Mn or Nb for strength enhancement becoming a *** stress-assisted corrosion behavior of a novel designed high-strength 3Ni steel was investigated in the current study using the corrosion big data *** information on the corrosion process was recorded using the galvanic corrosion current monitoring *** gradi-ent boosting decision tree(GBDT)machine learning method was used to mine the corrosion mechanism,and the importance of the struc-ture factor was *** exposure tests were conducted to verify the calculated results using the GBDT *** indic-ated that the GBDT method can be effectively used to study the influence of structural factors on the corrosion process of 3Ni ***-ferent mechanisms for the addition of Mn and Cu to the stress-assisted corrosion of 3Ni steel suggested that Mn and Cu have no obvious effect on the corrosion rate of non-stressed 3Ni steel during the early stage of *** the corrosion reached a stable state,the in-crease in Mn element content increased the corrosion rate of 3Ni steel,while Cu reduced this *** the presence of stress,the increase in Mn element content and Cu addition can inhibit the corrosion *** corrosion law of outdoor-exposed 3Ni steel is consistent with the law based on corrosion big data technology,verifying the reliability of the big data evaluation method and data prediction model selection.

关键词： weathering steel stress-assisted corrosion gradient boosting decision tree machining learning

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Elevated CO_(2) increases soil redox potential by promoting root radial oxygen loss in paddy field

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Journal of Environmental Sciences 2024年第2期136卷 11-20页

作者： Jie li Han Zhang Wenyi Xie cheng liu Xiaoyu liu Xuhui Zhang lianqing li Genxing Pan Institute of Resource Ecosystem and Environment of AgricultureNanjing Agricultural UniversityNanjing 210095China College of Agriculture Nanjing Agricultural UniversityNanjing 210095China

Soil redox potential(Eh)plays an important role in the biogeochemical cycling of soil *** its effect soil process and nutrients'availability under elevated atmospheric CO_(2) concentration and warming has seldom been ***,in this study,a field experiment was used to elucidate the effect of elevated CO_(2) concentration and warming on soil Eh,redox-sensitive elements and root radial oxygen loss(ROL).We hypothesized elevated CO_(2) and warming could alter soil Eh by promoting or inhibiting *** found that soil Eh in the rhizosphere was significantly higher than that of *** CO_(2) enhanced soil Eh by 11.5%,which corresponded to a significant decrease in soil Fe^(2+)and Mn^(2+)*** elevated CO_(2),the concentration of Fe^(2+)and Mn^(2+)decreased by 14.7%and 13.7%,*** also found that elevated CO_(2) altered rice root aerenchyma structure and promoted rice root *** elevated CO_(2),rice root ROL increased by 79.5%and 112.2%for Yangdao 6 and Changyou 5,*** had no effect on soil Eh and rice root *** warming increased the concentration of Mn^(2+)and SO_(4)^(2-)by 4.9%and 19.3%,*** was a significant interaction between elevated CO_(2) and warming on Fe^(2+)and Mn^(2+).Under elevated CO_(2),warming had no effect on the concentration of Fe^(2+)but decreased Mn^(2+)concentration *** study demonstrated that elevated atmospheric CO_(2) in the future could increase soil Eh by promoting rice root ROL,which will alter some soil nutrients'availability,such as Fe^(2+)and Mn^(2+).

关键词： Atmospheric CO_(2)enrichment Global warming Soil redox potential FACE Rice root aerenchyma

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Development characteristics and controlling factors of fractures in lacustrine shale and their geological significance for evaluating shale oil sweet spots in the third member of the Shahejie Formation in the Qikou Sag, Bohai Bay Basin

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Petroleum Science 2024年第2期21卷 791-805页

作者： Xu Zeng Tao Yang Jian-Wei Feng Cong-sheng Bian Ming Guan Wei liu Bing-cheng Guo Jin Dong Research Institute of Petroleum Exploration and Development China National Petroleum CorporationBeijing100083China College of Geosciences China University of Petroleum(Beijing)Beijing102249China Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China School of Earth Sciences China University of PetroleumQingdao266400ShandongChina

Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fractures, remain controversial. In this study, we integrate thin section analysis and microcomputed tomography(CT) data from several lacustrine shale samples from the third member(Es3) of the Shahejie Formation, Qikou Sag, Bohai Bay Basin, to assess the fractures in detail. The goal is to reveal the development characteristics, controlling factors, and geological significance for evaluating sweet spots in a shale oil play. The fractures in the Es3contain high-angle structural and horizontal bed-parallel fractures that are mostly shear and extensional. Various factors influence fracture development,including lithofacies, mineral composition, organic matter content, and the number of laminae. Structural fractures occur predominantly in siltstone, whereas bed-parallel fractures are abundant in laminated shale and layered mudstone. A higher quartz content results in higher shale brittleness, causing fractures, whereas the transformation between clay minerals contributes to the development of bedparallel fractures. Excess pore pressure due to hydrocarbon generation and expulsion during thermal advance can cause the formation of bed-parallel fractures. The density of the bed-parallel and structural fractures increases with the lamina density, and the bed-parallel fractures are more sensitive to the number of laminae. The fractures are critical storage spaces and flow conduits and are indicative of sweet spots. The laminated shale in the Es3with a high organic matter content contains natural fractures and is an organic-rich, liquid-rich, self-sourced shale play. Conversely, the siltstone, massive mudstone, and argillaceous carbonate lithofacies contain lower amounts of organic matter and do not have bed-parallel fractures. However, good reservoirs can form in th

关键词： Fractures Development characteristics Controlling factors Shale oil Sweet spot

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Advancing large-scale thin-film PPLN nonlinear photonics with segmented tunable micro-heaters

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Photonics Research 2024年第8期12卷 1703-1708页

作者： XIAOTING li HAOCHUAN li ZHENZHENG WANG ZHAOXI CHEN FEI MA KE ZHANG WENZHAO SUN cheng WANG Department of Electrical Engineering City University of Hong KongHong KongChina School of Physics Sun Yat-sen UniversityGuangzhou 510275China City University of Hong Kong(Dongguan) Dongguan 523808China Center of Information and Communication Technology City University of Hong Kong Shenzhen Research InstituteShenzhen 518057China State Key Laboratory of Terahertz and Millimeter Waves City University of Hong KongHong KongChina

Thin-film periodically poled lithium niobate(TF-PPLN)devices have recently gained prominence for efficient wavelength conversion processes in both classical and quantum ***,the patterning and poling of TF-PPLN devices today are mostly performed at chip scales,presenting a significant bottleneck for future largescale nonlinear photonic systems that require the integration of multiple nonlinear components with consistent performance and low ***,we take a pivotal step towards this goal by developing a wafer-scale TF-PPLN nonlinear photonic platform,leveraging ultraviolet stepper lithography and an automated poling *** address the inhomogeneous broadening of the quasi-phase matching(QPM)spectrum induced by film thickness variations across the wafer,we propose and demonstrate segmented thermal optic tuning modules that can precisely adjust and align the QPM peak wavelengths in each *** the segmented micro-heaters,we show the successful realignment of inhomogeneously broadened multi-peak QPM spectra with up to 57%enhancement of conversion *** achieve a high normalized conversion efficiency of 3802%W-1cm-2in a 6 mm long PPLN waveguide,recovering 84%of the theoretically predicted efficiency in this *** advanced fabrication techniques and segmented tuning architectures presented herein pave the way for wafer-scale integration of complex functional nonlinear photonic circuits with applications in quantum information processing,precision sensing and metrology,and low-noise-figure optical signal amplification.

关键词： tuning tunable waveguide

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Rational design of vitamin C/defective carbon van der Waals heterostructure for enhanced activity,durability and storage stability toward oxygen reduction reaction

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Journal of Energy Chemistry 2024年第1期88卷 103-111,I0003页

作者： Ruiqi cheng Kaiqi li Huanxin li Tianshuo Zhao Yibo Wang Qingyue Xue Jiao Zhang Chaopeng Fu Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Christopher Ingold Laboratory Department of ChemistryUniversity College LondonLondon WC1H 0AJUK Department of Chemistry Physical&Theoretical Chemistry LaboratoryUniversity of OxfordSouth Parks RoadOxford OX13QZUK

Metal-free defective carbon materials with abundant active sites have been widely studied as low-cost and efficient oxygen reduction reaction(ORR)electrocatalysts in metal-air ***,the active sites in defective carbon are easily subjected to serious oxidation or hydroxylation during ORR or storage,leading to rapid degradation of ***,we design a van der Waals heterostructure comprised of vitamin C(VC)and defective carbon(DC)to not only boost the activity but also enhance the durability and storage stability of the DC-VC *** formation of VC van der Waals between DC and VC is demonstrated to be an effective strategy to protect the defect active sites from oxidation and hydroxylation degradation,thus significantly enhancing the electrochemical durability and storage anti-aging ***,the DC-VC van der Waals can reduce the reaction energy barrier to facilitate the *** findings are also confirmed by operando Fourier transform infrared spectroscopy and density functional theory *** is necessary to mention that the preparation of this DC-VC electrocatalyst can be scaled up,and the ORR performance of the largely produced electrocatalyst is demonstrated to be very ***,the DC-VC-based aluminum-air batteries display very competitive power density with good performance maintenance.

关键词： Van der Waals heterostructure Oxygen reduction reaction Stability Scalable production Aluminum-air battery

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Amide naphthotubes:Biomimetic macrocycles for selective molecular recognition

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Chinese Chemical Letters 2024年第4期35卷 124-131页

作者： cheng-Da Zhao Huan Yao Shi-Yao li Fangfang Du li-li Wang liu-Pan Yang School of Pharmaceutical Science Postdoctoral Research Station of Basic MedicineHengyang Medical SchoolUniversity of South ChinaHengyang 421001China

Selective molecular recognition in water is routine for bioreceptors,but remains challenging for synthetic *** is principally because noncovalent interactions are usually less efficient in aqueous *** mimicking the cavity feature of bioreceptors,*** Jiang proposed and clarified the concept of“endo-functionalized cavity”.Through situating polar binding sites into a deep hydrophobic cavity,we designed and synthesized several macrocyclic hosts,among which amide naphthotubes are the most *** hosts can selectively recognize various polar molecules including organic micropollutants,drug molecules,and chiral molecules in water by employing the hydrophobic effect and shielded hydrogen *** addition,these biomimetic hosts have been applied in spectroscopic analysis,adsorptive separation and *** this review,we provide an overview of recent advances on amide naphthotubes with special emphasis on the efforts of Jiang's *** are convinced that these biomimetic macrocycles will make further contributions to supramolecular chemistry and beyond.

关键词： Molecular recognition Supramolecular chemistry Amide naphthotube Endo-functionalized cavity Biomimetic macrocycle

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Infiltration,runoff,and slope stability behaviors of infinite slope with macropores based on an improved Green–Ampt model

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Journal of Mountain Science 2024年第7期21卷 2220-2235页

作者： li Shanghui WU Guoxiong QUE Yun JIANG Zhenliang cheng Gaoyun College of Intelligent Construction Fuzhou University of International Studies and TradeFuzhou 350202China College of Civil Engineering Chongqing Jiao Tong UniversityChongqing 400074China Chongqing Vocational College of Architectural Engineering Chongqing 400072China College of Civil Engineering Fuzhou UniversityFuzhou 350000China Department of Civil and Environmental Engineering Hong Kong University of Science and TechnologyHong Kong 999077China T.Y.lin International Engineering Consulting(China)Co.Ltd Chongqing 401120China

Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is *** paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e.,matrix and macropore)and ponding condition,and proposed the infiltration equations,infiltration–runoff coupled model,and safety factor calculation *** show that the infiltration processes of macropore slope can be divided into three stages,and the proposed model is rational by a comparative *** wetting front depth of the traditional unsaturated slope is 17.2%larger than that of the macropore slope in the early rainfall stage and 27%smaller than that of the macropore slope in the late rainfall ***,macropores benefit the slope stability in the early rainfall but not in the *** flow does not occur initially but becomes pronounced with increasing rainfall *** equal depth of the wetting front in the two domains is regarded as the onset criteria of macropore *** analysis shows that macropore flow is delayed by increasing proportion of macropore domain(ω_(f)),whereas promoted by increasing ratio of saturated permeability coefficients between the two domains(μ).The increasing trend of ponding depth is sharp at first and then grows ***,when rainfall duration is less than 3 h,ωf andμhave no significant effect on the safety factor,whereas it decreases with increasingωf and increases with increasingμunder longer duration(≥3 h).With the increase ofω_(f),the slope maximum instability time advances by 10.5 h,and with the increase ofμ,the slope maximum instability time delays by 3.1 h.

关键词： Macropore slope Green–Ampt infiltration model Equivalent wetting front Ponding response time Slope stability

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Ensemble projections of climate and streamflow in a typical basin of semi-arid steppes in Mongolian Plateau of 2021-2100

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Advances in Climate Change Research 2024年第2期15卷 230-243页

作者： Hang PAN Jian-Ping TANG liang cheng Man-Chun li Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology Nanjing UniversityNanjing 210023China School of Geography and Ocean Science Nanjing UniversityNanjing 210023China Key Laboratory of Mesoscale Severe Weather/Ministry of Education Nanjing UniversityNanjing 210023China School of Atmospheric Sciences Nanjing UniversityNanjing 210023China

The Kherlen River is the main water source for Hulun Lake,the largest lake in northern *** to reduced inflow from the Kherlen River,Hulun Lake experienced rapid shrinkage at the beginning of the 21st century,posing a serious threat to the ecological security of northern ***,there is still a significant lack of projections regarding future climate change and its hydrological response in the Kherlen River *** study analyzed the projected climate and streamflow changes in the Kherlen River basin,a vital yet vulnerable international semi-arid steppes type basin.A combination of multi-model ensemble projection techniques,and the soil and water assessment tool(SWAT)model was employed to examine the spatio-temporal changes in precipitation,temperature,streamflow,and the associated uncertainties in the *** temperature(an increase of 1.84-6.42℃)and the precipitation(an increase of 15.0-46.0 mm)of Kherlen River basin are projected to increase by 2100,leading to a rise in streamflow(1.08-4.78 m^(3) s^(-1)).The upstream of the Kherlen River exhibits remarkable increasing trends in precipitation,which has a dominant influence on streamflow of Kherlen *** increases in streamflow are observed in April,August,September,and October compared to the reference period(1971-2000).These findings suggest a partial alleviation of water scarcity in the Kherlen River,but also an increased likelihood of hydrological extreme *** projected temperature increase in the Kherlen River basin exhibits the smallest uncertainty,while more pronounced uncertainties are found in precipitation and *** spread among the results of CMIP6 models is greater than that of CMIP5 models,with lower signal-to-noise ratio(SNR)values for temperature,precipitation,and streamflow.

关键词： Climate change Flow projection Uncertainty SWAT Mongolian Plateau

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Inner-shell ionization cross sections of atoms by positron impact

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Communications in Theoretical Physics 2024年第6期76卷 142-147页

作者： Yuan-cheng Wang Jia Ma li-Guang Jiao Stephan Fritzsche College of Physical Science and Technology Shenyang Normal UniversityShenyang 110034China Helmholtz-Institut Jena D-07743 JenaGermany GSI Helmholtzzentrum für Schwerionenforschung GmbH D-64291 DarmstadtGermany College of Science Shenyang Aerospace UniversityShenyang 110136China College of Physics Jilin UniversityChangchun 130012China Theoretisch-Physikalisches Institut Friedrich-Schiller-Universität Jena07743 JenaGermany

The relativistic binary-encounter-Bethe model with Wannier-type threshold law is employed to obtain the inner-shell ionization cross sections of multi-electron atoms(Ni,Cu,Y,Ag,Au,Yb,Ta,and Pb)for positron impact energies from the thresholds up to 105ke *** is good agreement between the present calculations and the experimental *** constant in the acceleration term derived from the Wannier law is determined to be 0.2 and 0.5 for the K-and L-shells,respectively.

关键词： positron scattering ionization cross section binary-encounter-Bethe model

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Activatable photoacoustic bioprobe for visual detection of aging in vivo

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Chinese Chemical Letters 2024年第4期35卷 324-329页

作者： Zihong li Jie cheng Ping Huang Guoliang Wu Weiying lin Institute of Optical Materials and Chemical Biology Guangxi Key Laboratory of Electrochemical Energy MaterialsSchool of Chemistry and Chemical EngineeringGuangxi UniversityNanning 530004China

Aging is a natural physiological process with various challenges, related to the loss of homeostasis within the organism, which is not a disease, but a significantly strong risk factor for multiple diseases, including myocardial infarction, stroke, some age-related cancers, macular degeneration, osteoarthritis, neurodegeneration, and many others. In the body, the main manifestation of aging is cellular aging, which exists within tissues and has a local or global impact on tissue function. However, the lack of effective aging detection tools has always been an issue that cannot be ignored in the field of aging research. Therefore,it is necessary to construct a non-invasive tool for in vivo detection of aging. Here, we show that the photoacoustic probe(LGAL), which has peak excitation and emission wavelengths in the near-infrared optical window, binds in vivo and at high contrast to the hallmark of aging, and allows for the microscopic imaging of aging through the intact mice. Firstly, this tool LGAL has been successfully applied to detect senescence in cells, displaying stronger photoacoustic signals than normal cells. Then, by using the photoacoustic probe, the blood vessels and tissues inside the mice can be visualized. Young and elderly mice exhibit varying intensities of photoacoustic signals, marking the first time a probe has been used to explore the aging of blood vessels and tissues inside the mice. Finally, we monitored the changes in the degree of aging during tumor treatment under photoacoustic(PA) imaging for the first time. As the treatment time increased, the degree of aging of the tumor gradually deepened. We expect the powerful tool could be a noninvasive and powerful tool for the study of aging biology.

关键词： Near-infrared Photoacoustic Aging Senescence Tumor Sa-β-gal

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