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mechanism of a dual-phase Ti-Nb alloy exhibiting near-linear elastic deformation

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Rare metals 2024年第5期43卷 2282-2289页

作者： Yan Guo wang Ding Wen ma Shun Guo Hao-Dong m.ng nian-Yao Xu School of Automotive Engineering Changzhou Institute of TechnologyChangzhou 213032China School of materials Science and Engineering Jiangsu UniversityZhenjiang 212013China Youke Publishing Co. LtdChina Grinm Group Co.LtdBeijing 100088China

In this work,the underlying mechanism responsible for the near-linear elastic deformation behavior of a dual-phase Ti-Nb alloy consisting of β and α'' phase with large recoverable strain was systematically *** on in situ synchrotron X-ray diffraction(SXRD)analyses,it was found that besides intrinsic elastic deformation,a slight reversible β-α'' stress-induced martensitic(SIm)transformation,which proceeded in a consecutive mode under the retarding effect of micro-defects,took place during the near-linear elastic *** unloading,a small amount of residual macroscopic strain remained in the specimen due to the incomplete reverse α''→β transformation on *** high near-linear elastic deformability of the cold drawing(CD)Ti-Nb alloy has been revealed to be attributed to the coupling actions of intrinsic elasticity as well as the consecutive and reversible β-α'' SIm *** research may contribute to a new avenue for the design and development of novel dual-phase Ti-based alloys with desirable elastic deformability.

关键词： Titanium alloys Dual-phase Near-linear elastic deformation martensitictransformation

Three-year field study on grass growth and soil hydrological properties in biochar-amended soil

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Journal of Rock mechanics and Geotechnical Engineering 2024年第7期16卷 2764-2774页

作者： Haowen Guo Charles wang Wai ng Junjun Ni Qi Zhang Yuchen wang Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina School of Transportation Southeast UniversityNanjingChina

Field monitoring was conducted to investigate and quantify the long-term effects of peanut shell biochar on soil-grass interaction over three *** 10 m5 m grassed plots were constructed in completely decomposed granitic *** of them were amended,respectively,with 5%and 10%biochar contents(m^(3)/m^(3))for grass growth,while the third was without biochar *** the threeyear monitoring,plant characteristics,saturated water permeability(k_(s))of grassed soil and soil suction were *** monitored results show that the grass leaf area index(LAI)and root length density(RLD)with biochar amendment were improved by 38%and 200%,*** the grassed plot without biochar,a threshold RLD existed with a value of 1.7 cm/cm^(3),beyond which k_(s) raised *** threshold RLD increased by 52%when biochar content increased from 0%to 10%.This implies that biochar may restrict the increase in k_(s) of grassed soil due to the rise in the threshold *** presence of biochar and grass can retain over 100%higher suction after heavy rainfalls,while 54%lower peak suction under evapotranspiration(ET)compared with the non-amended *** can alleviate the negative effects on hydraulic properties caused by plant growth and reduce ET-induced excessive water loss.A 5%peanut shell biochar content is recommended for the long-term management of vegetated earthen infrastructures.

关键词： Soil-grass interaction Biochar Long-term Water infiltration Soil drying

Summer Warm.ng Limited Bud Output Drives a Decline in Daughter Shoot Biomass through Reduced Photosynthetis of Parent Shoots in Leymus chinensis Seedlings

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Phyton-International Journal of Experimental Botany 2024年第7期93卷 1667-1675页

作者： Song Gao Ruocheng Xu Lin Li Jiao wang nian Liu Johannes m.H.Knops Junfeng wang Graduate School Changchun UniversityChangchun130022China Key Laboratory of Vegetation Ecology Ministry of EducationInstitute of Grassland ScienceSchool of Life SciencesJilin Songnen Grassland Ecosystem National Observation and Research StationNortheast Normal UniversityChangchun130024China Jilin Agricultural Radio and Television School Changchun130599China Department of Health and Environmental Sciences Xi’an Jiaotong Liverpool UniversitySuzhou215000China

Understanding how summer warm.ng inﬂuences the parent and daughter shoot production in a perennial clonal grass is vital for comprehending the response of grassland productivity to global ***,we conducted a simulated experiment using potted Leymus chinensis,to study the relationship between the photosynthetic activ-ity of parent shoots and the production of daughter shoots under a whole(90 days)summer warm.ng scenario(+3°C).The results showed that the biomass of parents and buds decreased by 25.52%and 33.45%,respectively,under warm.ng *** reduction in parent shoot biomass due to warm.ng directly resulted from decreased leaf area(18.03%),chlorophyll a(18.27%),chlorophyll b(29.21%)content,as well as a reduction in net photosynthetic rate(7.32%)and the maximum quantum efﬁciency of photosystem II(PSII)photochemistry(4.29%).The decline in daughter shoot biomass was linked to a decrease in daughter shoot number(33.33%)by ***,the number of belowground buds increased by 46.43%.The results indicated that long-term summer warm.ng reduces biomass accumulation in parent shoot by increasing both limitation of stoma and ***,the parent shoot allocates relatively more biomass to the belowground organs to maintain the survival and growth of ***,buds,as a potential aboveground population,could remedy for the cur-rent loss of parent shoot density by increasing the number of future daughter shoots if summer warm.ng subsides.

关键词： Warm.ng parent shoot bud bank photosynthesis chlorophyllﬂuorescence Leymus chinensis

Optimized Auxiliary Frequency Control of Wind Farm Based on Piecewise Reduced-order Frequency Response model

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Journal of modern Power Systems and Clean Energy 2024年第3期12卷 791-802页

作者： Xu Zhang Chen Zhao Junchao ma Long Zhang Dan Sun Chenxu wang Yan Peng Heng nian the School of Electrical Engineering Zhejiang UniversityHangzhou 310058China Electric Power Research Institute of State Grid Zhejiang Electric Power Corporation Hangzhou 310014China

With the increasing wind power penetration in the power system,the auxiliary frequency control(AFC)of wind farm(WF)has been widely *** traditional system frequency response(SFR)model is not suitable for the wind power generation system due to its poor accuracy and *** this paper,a piecewise reduced-order frequency response(PROFR)model is proposed,and an optimized auxiliary frequency control(O-AFC)scheme of WF based on the P-ROFR model is ***,a full-order frequency response model considering the change in operating point of wind turbine is established to improve the *** order to simplify the fullorder model,a P-ROFR model with second-order structure and high accuracy at each frequency response stage is *** on the proposed P-ROFR model,the relationship between the frequency response indexes and the auxiliary frequency controller coefficients is expressed ***,an OAFC scheme with the derived explicit expression as the optimization objective is proposed in order to improve the frequency support capability on the premise of ensuring the full release of the rotor kinetic energy and the full use of the effect of time delay on frequency ***,the effectiveness of the proposed P-ROFR model and the performance of the proposed OAFC scheme are verified by simulation studies.

关键词： Frequency response piecewise reduced-order wind farm auxiliary frequency control

Semi-analytical solution for mechanical analysis of tunnels crossing strike-slip fault zone considering nonuniform fault displacement and uncertain fault plane position

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Journal of Central South University 2024年第6期31卷 2116-2136页

作者： YAng Heng-hong wang m.ng-nian YU Li ZHAng Xiao School of Civil Engineering Southwest Jiaotong UniversityChengdu 610036China State Key Laboratory of Intelligent Geotechnics and Tunnelling Southwest Jiaotong UniversityChengdu 610036China

The tunnel subjected to strike-slip fault dislocation exhibits severe and catastrophic *** existing analysis models frequently assume uniform fault displacement and fixed fault plane *** contrast,post-earthquake observations indicate that the displacement near the fault zone is typically nonuniform,and the fault plane position is *** this study,we first established a series of improved governing equations to analyze the mechanical response of tunnels under strike-slip fault *** proposed methodology incorporated key factors such as nonuniform fault displacement and uncertain fault plane position into the governing equations,thereby significantly enhancing the applicability range and accuracy of the *** contrast to previous analytical models,the maximum computational error has decreased from 57.1%to 1.1%.Subsequently,we conducted a rigorous validation of the proposed methodology by undertaking a comparative analysis with a 3D finite element numerical model,and the results from both approaches exhibited a high degree of qualitative and quantitative agreement with a maximum error of 9.9%.Finally,the proposed methodology was utilized to perform a parametric analysis to explore the effects of various parameters,such as fault displacement,fault zone width,fault zone strength,the ratio of maximum fault displacement of the hanging wall to the footwall,and fault plane position,on the response of tunnels subjected to strike-slip fault *** findings indicate a progressive increase in the peak internal forces of the tunnel with the rise in fault displacement and fault zone ***,an augmentation in fault zone width is found to contribute to a decrease in the peak internal *** example,for a fault zone width of 10 m,the peak values of bending moment,shear force,and axial force are approximately 46.9%,102.4%,and 28.7% higher,respectively,compared to those observed for a fault zone width of 50 ***,the

关键词： strike-slip fault tunnel engineering semi-analytical solution fault zone width nonuniform fault displacement uncertain fault plane position

RAD-seq data reveals robust phylogeny and morphological evolutionary history of Rhododendron

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Horticultural Plant Journal 2024年第3期10卷 866-878页

作者： Yuanting Shen Gang Yao Yunfei Li Xiaoling Tian Shim.ng Li nian wang Chengjun Zhang Fei wang Yongpeng ma Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China University of Chinese Academy of Sciences Beijing 100049China Beijing Genomics of Institute ShenzhenGuangdong 518120China Guiyang Institute of Humanities and Technology GuiyangGuizhou 550025China State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River College of ForestryShandong Agricultural UniversityTai'anShandong 271018China The Southwest China of Germplasm Bank of Wild Species Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China West China Subalpine Botanical Garden Institute of BotanyChinese Academy of SciencesChengduSichuan 611834China

Rhododendron is famous for its high ornamental ***,the genus is taxonomically difficult and the relationships within Rhododendron remain *** addition,the origin of key morphological characters with high horticulture value need to be *** problems largely hinder utilization of germplasm *** studies attempted to disentangle the phylogeny of Rhododendron,but only used a few genomic markers and lacked large-scale sampling,resulting in low clade support and contradictory phylogenetic ***,we used restriction-site associated DNA sequencing(RAD-seq)data and morphological traits for 144 species of Rhododendron,representing all subgenera and most sections and subsections of this species-rich genus,to decipher its intricate evolutionary history and reconstruct ancestral *** results revealed high resolutions at subgenera and section levels of Rhododendron based on RAD-seq *** optimal phylogenetic tree and split tree recovered five lineages am.ng ***(cladeⅠ)formed the basal *** and Azaleastrum formed cladeⅡand had sister ***Ⅲincluded all scaly rhododendron ***(cladeⅣ)formed a sister group to ***(cladeⅤ).The results of ancestral state reconstruction showed that Rhododendron ancestor was a deciduous woody plant with terminal inflorescence,ten stamens,leaf blade without scales and broadly funnelform corolla with pink or purple *** study shows significant distinguishability to resolve the evolutionary history of Rhododendron based on high clade support of phylogenetic tree constructed by RAD-seq *** also provides an example to resolve discordant signals in phylogenetic trees and demonstrates the application feasibility of RAD-seq with large amounts of missing data in deciphering intricate evolutionary ***,the reconstructed ancestral state of six important characters provides insights into the inn

关键词： Rhododendron RAD-seq missing data Quartet sampling(QS) Ancestral state reconstruction

Numerical study of a bi-directional in-band pumped dysprosium-doped fluoride fiber laser at 3.2μm

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Frontiers of Information Technology & Electronic Engineering 2024年第7期25卷 1017-1024页

作者： Lingjing LI Chunyang mA nian ZHAO Jie PEng Bin LIU Haining JI Yuchen wang Pinghua TAng School of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China Research Center of Circuits and Systems Peng Cheng LaboratoryShenzhen 518055China Shanghai Institute of Optics and Fine mechanics Chinese Academy of SciencesShanghai 201899China

Dy^(3+)-doped fluoride fiber lasers have important applications in environment monitoring,real-time sensing,and polymer *** present,achieving a high-efficiency and high-power Dy^(3+)-doped fluoride fiber laser in the mid-infrared(mid-IR)region over 3μm is a scientific and technological ***,Dy^(3+)-doped fluoride fiber lasers use a unidirectional pumping method,which suffers from the drawback of high thermal loading density on the fiber tips,thus limiting power *** this study,a bi-directional in-band pumping scheme,to address the limitations of output power scaling and to enhance the efficiency of the Dy^(3+)-doped fluoride fiber laser at 3.2μm,is investigated numerically based on rate equations and propagation *** simulation results reveal that the optical‒optical efficiency of the bi-directional in-band pumped Dy^(3+)-doped fluoride fiber laser can reach 75.1%,approaching the Stokes limit of 87.3%.The potential for further improvement of the efficiency of the Dy^(3+)-doped fluoride fiber laser is also *** bi-directional pumping scheme offers the intrinsic advantage of mitigating the thermal load on the fiber tips,unlike unidirectional pumping,in addition to its high *** a result,it is expected to significantly scale the power output of Dy^(3+)-doped fluoride fiber lasers in the mid-IR regime.

关键词： mid-infrared laser Fiber laser Bi-directional pumping

Advances of machine learning in materials science: Ideas and techniques

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Frontiers of physics 2024年第1期19卷 155-194页

作者： Sue Sin Chong Yi Sheng ng Hui-Qiong wang Jin-Cheng Zheng Department of New Energy Science and Engineering Xiamen University MalaysiaSepang 43900Malaysia Engineering Research Center of micro-nano Optoelectronic materials and Devices Ministry of EducationFujian Key Laboratory of Semiconductor Materials and ApplicationsCI Center for OSEDand Department of PhysicsXiamen UniversityXiamen 361005China

In this big data era, the use of large dataset in conjunction with machine learning (mL) has been increasingly popular in both industry and academia. In recent times, the field of materials science is also undergoing a big data revolution, with large database and repositories appearing everywhere. Traditionally, materials science is a trial-and-error field, in both the computational and experimental departments. With the advent of machine learning-based techniques, there has been a paradigm shift: materials can now be screened quickly using mL models and even generated based on materials with similar properties;mL has also quietly infiltrated many sub-disciplinary under materials science. However, mL remains relatively new to the field and is expanding its wing quickly. There are a plethora of readily-available big data architectures and abundance of mL models and software;The call to integrate all these elements in a comprehensive research procedure is becom.ng an important direction of material science research. In this review, we attempt to provide an introduction and reference of mL to materials scientists, covering as much as possible the commonly used methods and applications, and discussing the future possibilities.

关键词： machine learning materials science

modelling the water diversion of a sustainable cover system under humid climates

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Journal of Rock mechanics and Geotechnical Engineering 2024年第7期16卷 2429-2440页

作者： Haowen Guo Charles wang Wai ng Qi Zhang Chuanxiang Qu Liwen Hu Shenzhen Research Institute of Hong Kong University of Science and Technology Shenzhen518057China Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong Kong SAR999077China CCCC Fourth Harbor Engineering Institute Co. LtdGuangzhou510230China

Extreme rainfall significantly threatens the safety of the landfill cover system,especially under humid *** study aims to provide design recommendations for a sustainable landfill cover system consisting of a low-permeability soil layer underlying a two-layer capillary barrier for humid ***,the numerical back-analysis was conducted for verification against a series of flume model ***,a parametric study was performed to investigate the effects of inclination angle,particle size and layer thickness on the lateral diversion length(DL)of the three-layer cover system under the 100-year return period rainfall of humid *** results show that the water lateral DL of the cover system can be greatly enhanced by increasing the inclination angle from 3°to 18°.moreover,the bottom layer of the cover system with a coarser d10 was more susceptible to the impact of the heavy rainfall,while this can be alleviated by increasing the thickness of the bottom layer.A dimensionless number,defined as the ratio of thickness and d_(10) of the bottom layer,is proposed for designing lateral diversion of the three-layer cover system under humid *** preserve the maximum DL,it is suggested that the proposed dimensionless number should be larger than 95 and 110 for the design of rainfall events with 50-year and 100-year return periods for humid climates,respectively.

关键词： Unsaturated soil Recycling Construction waste Three-layer landfill cover Water infiltration