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Plant Diversity 2025年第1期47卷 21-33页

作者： Liansheng Xu Zhuqiu Song Tian Li Zichao Jin Buyun Zhang Siyi Du Shuyuan Liao Xingjie Zhong Yousheng Chen Plant Science research Center South China Botanical GardenChinese Academy of SciencesGuangzhou 510650China Key Laboratory of National Forestry and Grassland Administration on Plant co.servation and Utilization in Southern china Guangzhou 510650China University of the Chinese academy of Sciences Beijing 100049China Central-Southern Safety and Environment Technology Institute co. LTDWuhan 430064China

Saussurea is one of the largest and most rapidly evolving genera within the Asteraceae,co.prising approximately 520 species from the Northern Hemisphere.A co.prehensive infrageneric classification,supported by robust phylogenetic trees and co.roborated by morphological and other data,has not yet been *** the first time,we reco.ered a well-resolved nuclear phylogeny of Saussurea co.sisting of four main clades,which was also supported by morphological *** analyses show that ancient hybridization is the most likely source of deep cytoplasmic-nuclear co.flict in Saussurea,and a phylogeny based on nuclear data is more suitable than one based on chloroplast data for exploring the infrageneric classification of *** on the nuclear phylogeny obtained and morphological characters,we proposed a revised infrageneric taxonomy of Saussurea,which includes four subgenera and 13 ***,1)***,***,***,and *** were moved from *** to ***,2)*** was moved from *** to ***,and 3)*** was moved from *** to ***.

关键词： Asteraceae Morphology Next-generation sequencing Phylogenomics Subgenus

Performance Evaluation of Damaged T-Beam Bridges with External Prestressing Reinforcement Based on Natural Frequencies

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Structural Durability & Health Monitoring 2025年第2期19卷 399-415页

作者： Menghui Hao Shanshan Zhou Yongchao Han Zhanwei Zhu Qiang Yang Panxu Sun Jiajun Fan Henan Zhonggong Design&research Group co. Ltd.Zhengzhou450000China School of Civil Engineering Zhengzhou UniversityZhengzhou450001China

As an evaluation index,the natural frequency has the advantages of easy acquisition and quantitative *** this paper,the natural frequency is used to evaluate the performance of external cable reinforced *** examples show that co.pared with the natural frequencies of first-order modes,the natural frequencies of higher-order modes are more sensitive and can reflect the damage situation and external cable reinforcement effect of T-beam *** damaged bridges,as the damage to the T-beam increases,the natural frequency value of the bridge gradually *** the degree of local damage to the beam reaches 60%,the amplitude of natural frequency change exceeds 10%for the first *** natural frequencies of the firstorder vibration mode and higher-order vibration mode can be selected as indexes for different degrees of the damaged T-beam *** damaged bridges reinforced with external cables,the traditional natural frequency of the first-order vibration mode cannot be used as the index,which is insensitive to changes in prestress of the external *** natural frequencies of higher-order vibration modes can be selected as indexes,which can reflect the reinforcement effect of externally prestressed damaged T-beam bridges,and its numerical value increases with the increase of external prestressed cable force.

关键词： Performance evaluation natural frequency T-beam bridge damage external cable reinforcement

Effects of surface fluoride modification on TiO_(2)for the photocatalytic oxidation of toluene

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Journal of Environmental Sciences 2025年第1期147卷 561-570页

作者： Shaoyu Yuan Min Chen Xiaoxiao Qin Xueyan Chen Jianghao Zhang Changbin Zhang State Key Joint Laboratory of Environment Simulation and Pollution co.trol Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese academy of Sciences Beijing 100049China

In the present study,we investigated the influence of surface fluorine(F)on TiO_(2)for the photocatalytic oxidation(Pco.of ***_(2)modified with different F co.tent was prepared and *** was found that with the increasing of F co.tent,the toluene co.version rate first increased and then ***,co.(2)mineralization efficiency showed the opposite *** on the characterizations,we revealed that F substitutes the surface hydroxyl of TiO_(2)to form the structure of≡*** presence of the appropriate amount of surface≡Ti-F on TiO_(2)greatly enhanced the separation of photogenerated carriers,which facilitated the generation of·OH and promoted the activity for the Pco.of *** was further revealed that the increase of only·OH promoted the co.version of toluene to ring-co.taining intermediates,causing the accumulation of intermediates and then co.versely inhibited the·OH generation,which led to the decrease of the co.(2)mineralization *** above results co.ld provide guidance for the rational design of photocatalysts for toluene oxidation.

关键词： Photocatalysis TiO_(2) Toluene Fluorine

Reco.structing forest and grassland co.er changes in china over the past millennium

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Science china Earth Sciences 2025年第1期68卷 94-110页

作者： Fanneng HE Fan YANG Yafei WANG Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China Key research Institute of Yellow River Civilization and Sustainable Development Henan UniversityKaifeng475001China University of Chinese academy of Sciences Beijing100049China

Historical forest and grassland co.er changes not only are critical indicators for quantifying eco.ogical and environmental change processes but also serve as fundamental data for long-term climate change simulations and terrestrial eco.ystem carbon emission ***,because of limitations in historical data,quantitative estimations and spatially gridded reco.structions of these changes remain challenging,necessitating further methodological *** study focused on china's present-day land area over the past millennium,objectively capturing the characteristics and drivers of forest and grassland co.er *** this basis,using the forest transition theory and the space-for-time substitution method,we depicted the historical deforestation process as an inverted“S”curve and developed a model to reco.struct historical forest area changes based on the functional relationship between the forest area and population size ***,a gridded forest allocation model was established on the basis of deforestation *** the grassland co.er,we implemented regionspecific methods,such as the cropland area deduction method and the habitat co.straint method,to quantitatively reco.struct historical ***,we obtained provincial forest and grassland area changes over the past millennium and mapped 10-km-resolution gridded data of forest and grassland *** results indicated the following.(1)The methods developed using population data as a proxy objectively reproduced the spatiotemporal evolution of forest and grassland co.er in china over the past *** feasible methods offer a novel pathway for the quantitative reco.struction of historical forest and grassland co.er changes.(2)The data indicated that china's forest area generally decreased over the past millennium,characterized by a“decrease-then-increase”*** forest area experienced three distinct phases:a slow decline(AD 1000–1650),a rapid decline(AD 16

关键词： Land use and land co.er change Forest Grassland Quantitative reco.struction Gridded reco.struction china historical period

Impacts of near-M_(s)austempering treatment on microstructure evolution and bainitic transformation kinetics of a medium Mn steel

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Journal of Iron and Steel research International 2025年第1期32卷 249-259页

作者： Yong-gang Yang Xin-yue Liu Rui-zhi Li Yu-lai Chen Hong-xiang Wu Guo-min Sun Zhen-li Mi National Engineering research Center for Advanced Rolling and Intelligent Manufacturing University of Science and Technology BeijingBeijing 100083China Technology Center Ningbo Iron&Steel Co.Ltd.Ningbo 315800ZhejiangChina

The microstructure evolution and bainitic transformation of an Fe-0.19C-4.03Mn-1.48Si steel subjected to near-M_(s)austempering treatment were systematically investigated by co.bining dilatometer,X-ray diffraction,and electron *** additional austempering treatments with isothermal temperatures above M_(s)were used as *** show that the incubation period for the bainitic transformation occurs when the medium Mn steel is treated with the austempering temperature above M_(s).However,when subjected to near-M_(s)isothermal treatment,the medium Mn steel does not show an incubation period and has the fastest bainitic transformation ***,the largest volume fraction of bainite with a value of 74.7%is obtained on the co.dition of near-M_(s)austempering treatment after co.ling to room *** and microstructure evolution analysis indicates that the elimination of the incubation period and the fastest rate of bainitic transformation are related to the preformed *** advent of preformed martensite allows the specimen to generate more bainite in a limited *** bainitic ferrite nucleation at austenite grain boundaries and through autocatalysis at ferrite/austenite interfaces,a model is established to understand the kinetics of bainite formation and it can describe the nucleation rate of bainitic transformation well when co.pared to the experimental results.

关键词： Medium manganese steel Bainitic transformation Microstructure Near-M_(s)austempering Transformation modeling

Applications of in-situ solid-state nuclear magnetic resonance in methanol to olefins reaction

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Science china Chemistry 2025年第1期68卷 134-151页

作者： Jing Niu Shutao Xu Yingxu Wei Zhongmin Liu National Engineering research Center of Lower-Carbon Catalysis Technology Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese academy of Sciences Beijing 100049China

The methanol-to-olefins(MTO)reaction offers an alternative pathway for the production of low-carbon olefins from non-oil *** research has been impeded by a lack of co.prehensive understanding of its underlying mechanism,despite the significant progress made in ***-situ solid-state nuclear magnetic resonance(ss NMR)spectrosco.y has emerged as a pivotal tool,offering crucial insights into key species under real-time operando ***,the host–guest interaction between zeolites or surface species residing on zeolites and the reactant/active intermediates is revealed by the co.bination of in-situ^(13)C MAS NMR and 2D co.relation ***,recent technological advancements in hyperpolarization(HP)methods,including HP^(129)Xe NMR and dynamic nuclear polarization(DNP),have significantly improved the sensitivity of ssNMR,enabling detailed structural and kinetic analysis as well as the detection of trace *** this feature article,we summarized recent advancements in(in-situ)ssNMR spectrosco.y applied to MTO reaction processes,enco.passing mechanistic investigations at various stages and the intricate host–guest *** theoretical insights into the dynamic evolution of MTO reactions lay a solid foundation for the optimization of catalytic processes and the development of efficient catalysts,thereby advancing the techniques towards more sustainable and eco.omical production route for olefins.

关键词： MTO zeolites in-situ ssNMR reactive intermediates reaction mechanism

Vibration safety assessment and parameter analysis of buried oil pipelines based on vibration isolation holes under strong surface impact

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Earthquake Engineering and Engineering Vibration 2025年第1期24卷 69-82页

作者： Wang Guobo Mei Hua Wang Jianning He Wei Yin Yao Zhai Yuxin Zuo Pengfei co.lege of Civil Engineering and Architecture Wenzhou UniversityWenzhou 325035China Zhejiang Engineering research Center of Disaster Prevention and Mitigation for co.stal Soft Soil Foundation WenZhou 325035China china National Machinery Industry co. Ltd.Beijing 100080China Faculty of Engineering China University of GeosciencesWuhan 430074China china Railway co.struction Group co. Ltd.Beijing 100072China School of Civil Engineering and Architecture Wuhan University of TechnologyWuhan 430070China

Strong surface impact will produce strong vibration,which will pose a threat to the safety of nearby buried pipelines and other important lifeline *** on the verified numerical method,a co.prehensive numerical parameter analysis is co.ducted on the key influencing factors of the vibration isolation hole(VIH),which include hole diameter,hole net spacing,hole depth,hole number,hole arrangement,and soil *** results indicate that a smaller ratio of net spacing to hole diameter,the deeper the hole,the multi-row hole,the hole adoption of staggered arrangements,and better site soil co.ditions can enhance the efficiency of the VIH *** average maximum vibration reduction efficiency within the vibration isolation area can reach 42.2%.The vibration safety of adjacent oil pipelines during a dynamic co.paction projection was evaluated acco.ding to existing standards,and the measurement of the VIH was reco.mended to reduce excessive *** single-row vibration isolation scheme and three-row staggered arrangement with the same hole parameters are suggested acco.ding to different *** research findings can serve as a reference for the vibration safety analysis,assessment,and co.trol of adjacent underground facilities under the influence of strong surface impact loads.

关键词： vibration isolation hole buried oil pipeline strong surface impact vibration velocity vibration safety assessment

Distribution and mapping of temperate savanna in the sandy lands of eastern china

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Science china Earth Sciences 2025年第1期68卷 128-141页

作者： Xiaoya LI Feng WANG Tao DUAN Kaijie YANG Bin YANG Chunmei WANG Xin TIAN Qi LU Institute of Eco.ogical co.servation and Restoration Institute of Desertification StudiesChinese Academy of ForestryBeijing100091China Institute of Desertification Institute of Desertification StudiesChinese Academy of ForestryBeijing100091China Institute of Great Green Wall Bayan Nur015200China Satellite Application Centre for Eco.ogy and Environment MEEBeijing100094China Institute of Microelectronics Chinese Academy of SciencesBeijing100029China Aerospace Information research Institute Chinese Academy of SciencesBeijing100094China Institute of Forest Resource Information Techniques Chinese Academy of ForestryBeijing100091China

Savannas are distributed globally across various *** perform a significant socioeco.omic role in regulating net primary productivity and the terrestrial carbon *** to the high spatial heterogeneity induced by the mixed distribution of trees and grasses,current global land-co.er classification maps often classify savannas as forests or grasslands Temperate savannas in china co.er a vast area,yet their spatial patterns and extent remain poorly *** study developed a novel remote sensing temperate savannas mapping method by integrating very high-resolution(VHR)unmanned aerial vehicle(UAV)and GF-6 satellite imagery based on the vegetation structure characteristics of temperate savannas using the FAO definition of *** and validation datasets were co.lected from VHR UAV imagery co.ering the main temperate savannah types with a ground area of 1818 *** fractional woody vegetation co.er(FWVC)and fractional herbaceous vegetation co.er(FHVC)in temperate savannas were estimated by integrating Classification and Regression Tree and Random Forest *** current distribution of temperate savannas in the Horqin and Otindag Sandy Lands of Eastern china was mapped to a unit area of 0.5 *** root-mean-square error(RMSE)values for the FWVC and FHVC models were 10.69%and 11.67%,and the R^(2)values were 0.66 and 0.63,*** assessment indicated that the new temperate savanna map had high identification accuracy,with a Kappa co.fficient of 0.70,overall accuracy of 0.88,and average accuracy of *** savannas in the sandy lands of eastern china were primarily distributed in the northern Horqin Sandy Land the central and eastern regions of the Otindag Sandy Land,and the transition zone from the southern slopes of the Greater Khingan Mountains to the plains,co.ering a total area of 3.27×10^(6)*** main savannah types were elm,oak/maple,and shrub *** savannas were widely distributed in the Otindag Sandy Land a

关键词： Temperate savanna UAV imagery GF-6 Fractional woody vegetation co.er Fractional herbaceous vegetation co.er Machine learning

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Isothermal reduction kinetics and reduction prediction for iron ore pellets

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Journal of Iron and Steel research International 2025年第1期32卷 64-72页

作者： Fei Meng Hao Liu Yue-lin Qin Huang-jie Hua Yin Deng Ze-zheng Sun Long-hai Liu School of Metallurgy and Materials Engineering Chongqing University of Science and TechnologyChongqing401331China CISDI Group co. Ltd.Chongqing401122China co.lege of Materials Science and Engineering Chongqing UniversityChongqing400044China Sichuan Desheng Group Vanadium&Titanium co. Ltd.Leshan614000SichuanChina

Iron ore pellets,as one of the main charges of blast furnaces,have a greater impact on the co.(2)emission reduction and stable operation of blast *** isothermal reduction behavior of the pellets obtained from a Chinese steel plant was studied in the gas mixtures of co.and N_(2).The results showed the reduction process is divided into two *** reduction in the initial stage(time t≤40 min)is co.peratively co.trolled by internal diffusion and interface chemical reactions with the activation energy of 30.19 and 16.67 kJ/mol,*** co.trolling step of the reduction in the final stage(t>40 min)is internal diffusion with the activation energy of 34.60 kJ/*** reduction process can be described by two equations obtained from kinetic *** reduction degree can be predicted under different temperatures and time,and the predicted results showed an excellent co.relation with the experimental *** reduction mechanisms were co.firmed by the analysis of the scanning electron microsco.e equipped with an energy dispersive spectrometer and optical microsco.e.

关键词： Pellet Reduction behavior Kinetics Mechanism Reduction prediction

Impact of Various Silico. Sources on the Synthesis of Mordenite and Differences in the Carbonylation Reaction of Dimethyl Ether

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Chemical research in Chinese Universities 2025年第1期41卷 59-65页

作者： CHEN Long WANG Yunzheng LV Jiangang YANG Weimin School of Chemical Engineering East China University of Science and TechnologyShanghai200237P.R.China Sinopec Shanghai research Institute of Petrochemical Technology co. Ltd.Shanghai201208P.R.China

This study introduces an innovative method for synthesizing mordenite(MOR)by employing a co.bination of water glass and fumed silica as the silica *** zeolite produced through this method exhibits a smaller grain size,a larger specific surface area,and a greater number of Brønsted acid sites co.pared to the co.ventionally synthesized mordenite using silica ***,the chemical environment of framework Al in MOR zeolites is influenced by different silica sources,leading to varied acid properties between the two MOR zeolites,which results in an enhanced activity of dimethyl ether carbonylation from 50%to over 83%.

关键词： Mordenite Silica source DME carbonylation