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Design Guidelines for Composition of Brazing Filler Metals and Evolution Mechanisms of Typical Microstructures 被引量:4
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作者 Long Weimin 《稀有金属材料与工程》 北大核心 2025年第4期837-853,共17页
Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler ... Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler metals is ever-increasing.It is of great significance to investigate the optimized composition design methods and to establish systematic design guidelines for brazing filler metals.This study elucidated the fundamental rules for the composition design of brazing filler metals from a three-dimensional perspective encompassing the basic properties of applied brazing filler metals,formability and processability,and overall cost.The basic properties of brazing filler metals refer to their mechanical properties,physicochemical properties,electromagnetic properties,corrosion resistance,and the wettability and fluidity during brazing.The formability and processability of brazing filler metals include the processes of smelting and casting,extrusion,rolling,drawing and ring-making,as well as the processes of granulation,powder production,and the molding of amorphous and microcrystalline structures.The cost of brazing filler metals corresponds to the sum of materials value and manufacturing cost.Improving the comprehensive properties of brazing filler metals requires a comprehensive and systematic consideration of design indicators.Highlighting the unique characteristics of brazing filler metals should focus on relevant technical indicators.Binary or ternary eutectic structures can effectively enhance the flow spreading ability of brazing filler metals,and solid solution structures contribute to the formability.By employing the proposed design guidelines,typical Ag based,Cu based,Zn based brazing filler metals,and Sn based solders were designed and successfully applied in major scientific and engineering projects. 展开更多
关键词 design of brazing filler metals design guidelines for composition Ag based brazing filler metals eutectic structures evolution
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Quantitative Analysis of the Fatty Acid Compositions of Different Oils and Associations with Antioxidant Capacity and Oxidative Stability 被引量:1
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作者 LIU Junchen SUN Xiaoman +3 位作者 ZHANG Huirong SHAO Haofan LING Xiao LI Li 《现代食品科技》 北大核心 2025年第4期305-315,共11页
Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships w... Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships with antioxidant activity and oxidative stability,gas chromatography-mass spectrometry was performed to characterize the associated fatty acid profiles.The antioxidant activity of vegetable oils,based on their DPPH-scavenging capacity(expressed as IC_(50) values),was used to assess their impact on human health,and their oxidative stability was characterized by performing lipid oxidation analysis to determine the oxidative induction time of fats and oils.In addition,correlation analyses were performed to examine associations between the fatty acid composition of the oils and DPPH-scavenging capacity and oxidative stability.The results revealed that among the assessed oils,coffee seed oil has the highest saturated fatty acid content(355.10 mg/g),whereas Garddenia jaminoides oil has the highest unsaturated fatty acid content(844.84 mg/g).Coffee seed oil was also found have the lowest DPPH IC_(50) value(2.30 mg/mL)and the longest oxidation induction time(17.09 h).Correlation analysis revealed a significant linear relationship(P<0.05)between oxidative stability and unsaturated fatty acid content,with lower contents tending to be associated with better oxidative stability.The findings of this study provide reference data for the screening of functional edible vegetable oils. 展开更多
关键词 gas chromatography-mass spectrometry vegetable oil fatty acid composition oxidative stability antioxidant capacity
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High-resolution Simulation Dataset of Hourly PM_(2.5)Chemical Composition in China(CAQRA-aerosol)from 2013 to 2020 被引量:1
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作者 Lei KONG Xiao TANG +14 位作者 Jiang ZHU Zifa WANG Bing LIU Yuanyuan ZHU Lili ZHU Duohong CHEN Ke HU Huangjian WU Qian WU Jin SHEN Yele SUN Zirui LIU Jinyuan XIN Dongsheng JI Mei ZHENG 《Advances in Atmospheric Sciences》 2025年第4期697-712,共16页
Scientific knowledge on the chemical compositions of fine particulate matter(PM_(2.5)) is essential for properly assessing its health and climate effects,and for decisionmakers to develop efficient mitigation strategi... Scientific knowledge on the chemical compositions of fine particulate matter(PM_(2.5)) is essential for properly assessing its health and climate effects,and for decisionmakers to develop efficient mitigation strategies.A high-resolution PM_(2.5) chemical composition dataset(CAQRA-aerosol)is developed in this study,which provides hourly maps of organic carbon,black carbon,ammonium,nitrate,and sulfate in China from 2013 to 2020 with a horizontal resolution of 15 km.This paper describes the method,access,and validation results of this dataset.It shows that CAQRA-aerosol has good consistency with observations and achieves higher or comparable accuracy with previous PM_(2.5) composition datasets.Based on CAQRA-aerosol,spatiotemporal changes of different PM_(2.5) compositions were investigated from a national viewpoint,which emphasizes different changes of nitrate from other compositions.The estimated annual rate of population-weighted concentrations of nitrate is 0.23μg m^(−3)yr^(−1) from 2015 to 2020,compared with−0.19 to−1.1μg m^(−3)yr^(−1) for other compositions.The whole dataset is freely available from the China Air Pollution Data Center(https://doi.org/10.12423/capdb_PKU.2023.DA). 展开更多
关键词 PM_(2.5)composition dataset black carbon organic carbon AMMONIUM NITRATE SULFATE
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Effect of preprocessing on performances of machine learning-based mineral composition analysis on gas hydrate sediments,Ulleung Basin,East Sea 被引量:1
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作者 Hongkeun Jin Ju Young Park +3 位作者 Sun Young Park Byeong-Kook Son Baehyun Min Kyungbook Lee 《Petroleum Science》 2025年第1期151-162,共12页
Gas hydrate(GH)is an unconventional resource estimated at 1000-120,000 trillion m^(3)worldwide.Research on GH is ongoing to determine its geological and flow characteristics for commercial produc-tion.After two large-... Gas hydrate(GH)is an unconventional resource estimated at 1000-120,000 trillion m^(3)worldwide.Research on GH is ongoing to determine its geological and flow characteristics for commercial produc-tion.After two large-scale drilling expeditions to study the GH-bearing zone in the Ulleung Basin,the mineral composition of 488 sediment samples was analyzed using X-ray diffraction(XRD).Because the analysis is costly and dependent on experts,a machine learning model was developed to predict the mineral composition using XRD intensity profiles as input data.However,the model’s performance was limited because of improper preprocessing of the intensity profile.Because preprocessing was applied to each feature,the intensity trend was not preserved even though this factor is the most important when analyzing mineral composition.In this study,the profile was preprocessed for each sample using min-max scaling because relative intensity is critical for mineral analysis.For 49 test data among the 488 data,the convolutional neural network(CNN)model improved the average absolute error and coefficient of determination by 41%and 46%,respectively,than those of CNN model with feature-based pre-processing.This study confirms that combining preprocessing for each sample with CNN is the most efficient approach for analyzing XRD data.The developed model can be used for the compositional analysis of sediment samples from the Ulleung Basin and the Korea Plateau.In addition,the overall procedure can be applied to any XRD data of sediments worldwide. 展开更多
关键词 Sample-based preprocessing X-ray diffraction(XRD) Machine learning Mineral composition Gas hydrate(GH) Ulleung basin
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Products of multiplication,composition and differentiation on weighted Bergman spaces in the unit ball
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作者 ZHANG Chao QIN Yuehai 《中山大学学报(自然科学版)(中英文)》 北大核心 2025年第2期160-169,共10页
The boundness and compactness of products of multiplication,composition and differentiation on weighted Bergman spaces in the unit ball are studied.We define the differentiation operator on the space of holomorphic fu... The boundness and compactness of products of multiplication,composition and differentiation on weighted Bergman spaces in the unit ball are studied.We define the differentiation operator on the space of holomorphic functions in the unit ball by radial derivative.Then we extend the Sharma's results. 展开更多
关键词 composition operator multiplication operator differentiation operator weighted Bergman space
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2-complex Symmetric Weighted Composition Operators on Fock Space of C^(N)
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作者 JIANG Zhijie 《数学进展》 北大核心 2025年第1期37-49,共13页
The aim of the present paper is to study 2-complex symmetric bounded weighted composition operators on the Fock space of C^(N) with the conjugations J and J_(t,A,b) defined by ■ respectively,where k(z_(1),...,z_N)=(... The aim of the present paper is to study 2-complex symmetric bounded weighted composition operators on the Fock space of C^(N) with the conjugations J and J_(t,A,b) defined by ■ respectively,where k(z_(1),...,z_N)=(■,...,■),t∈C,b∈C^(N) and A is a linear operator on C^(N).An example of 2-complex symmetric bounded weighted composition operator with the conjugation J_(t,A,b) is given. 展开更多
关键词 Fock space weighted composition operator 2-complex symmetric operator reproducing kernel function
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Both composition and configuration of forests and urban development shape bat activity and diversity in North American temperate forests
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作者 Sihao Chen Han Li 《Forest Ecosystems》 2025年第5期974-986,共13页
Temperate forest ecosystems are important habitats for many bat species. However, these habitats are increasingly affected by anthropogenic disturbances, particularly urban development, leading to landscapes with vary... Temperate forest ecosystems are important habitats for many bat species. However, these habitats are increasingly affected by anthropogenic disturbances, particularly urban development, leading to landscapes with varying land cover composition and configuration. Limited research has examined how forest and urban landscape composition and configuration influence bat activity and diversity. Using a multi-year statewide bat acoustic monitoring dataset from North Carolina, USA, we investigated the effects of forest and urban composition and configuration at multiple spatial scales on bat activity and diversity. First, we constructed single-variable landscape index regression models and found that both the composition and configuration of forests and urban developments influenced bat activity and diversity in a species-specific manner. Next, we applied a hierarchical partitioning approach to compare the relative contributions of composition and configuration indices in explaining variance in bat activity. For big brown bats and hoary bats, evergreen forest and urban development composition indices contributed the most to explaining activity variance. In contrast, for eastern red bats, evening bats, and tricolored bats, deciduous forest fragmentation indices describing landscape configuration were the most influential factors. Silver-haired bat activity variance was primarily explained by an evergreen forest fragmentation index. Lastly, urban development configuration indices were the strongest predictors of Mexican free-tailed bat activity and total bat activity. These results suggest that forest and urban landscape configuration should be considered in conservation and management planning for North American temperate forest ecosystems, particularly in regions that have not experienced drastic deforestation in recent decades. 展开更多
关键词 Bats CHIROPTERA composition Confguration FORESTS Landscape index Urban
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Composition Analysis of Lycophytes and Ferns in Yunzhongshan Nature Reserve, Fujian Province
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作者 Jinquan SHEN Minyong LU +4 位作者 Baohua WU Lingming LIN Jinhuo HE Ying FENG Yinbing XIE 《Plant Diseases and Pests》 2025年第2期34-37,共4页
[Objectives]To analyze the composition of lycophytes and ferns in Yunzhongshan Nature Reserve,Fujian Province.[Methods]This study examined the composition of lycophytes and ferns in Yunzhongshan Nature Reserve through... [Objectives]To analyze the composition of lycophytes and ferns in Yunzhongshan Nature Reserve,Fujian Province.[Methods]This study examined the composition of lycophytes and ferns in Yunzhongshan Nature Reserve through field investigations and specimen identification,supplemented by a review of relevant literature.[Results]A total of 84 species of lycophytes and ferns were identified,encompassing 55 genera and 29 families.This included 14 species of lycophytes distributed across 8 genera and 3 families,as well as 70 species of ferns belonging to 47 genera and 26 families.Polypodiaceae and Selaginella were the dominant family and genus,respectively,while oligospecific families and monotypic genera were significant components of lycophytes and ferns in the region.The distribution types of these families were primarily cosmopolitan and tropical.The Germline differentiation degree(SD)was 3.34,and the proportion of rare or endangered species among lycophytes and ferns was 8.33%.[Conclusions]Yunzhongshan Nature Reserve possesses a diverse array of lycophyte and fern species.This study offers valuable scientific insights that can inform efforts related to the conservation of biodiversity,resource utilization and development,species introduction,and system evolution of lycophytes and ferns within the reserve. 展开更多
关键词 NATURE RESERVE LYCOPHYTES FERNS composition
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Effects of composition ratio of TiCu precursor on dealloying behavior in molten Mg and microstructural characteristics of Mg-Ti composites
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作者 Jee Eun Jang Bo Hyun Park +1 位作者 Soo-Hyun Joo Sung Hyuk Park 《Journal of Magnesium and Alloys》 2025年第6期2784-2799,共16页
Metal composites produced through the liquid metal dealloying(LMD)process feature an advanced matrix-matrix composite structure,where two metallic materials form a continuous,three-dimensional interconnected network.T... Metal composites produced through the liquid metal dealloying(LMD)process feature an advanced matrix-matrix composite structure,where two metallic materials form a continuous,three-dimensional interconnected network.This study investigates the effects of Ti Cu precursor compositions on dealloying behavior and microstructural evolution in liquid Mg,using Ti_(50)Cu_(50)and Ti_(30)Cu_(70)precursors.The initial microstructure of the precursor significantly influences dealloying kinetics and phase transitions.The single-phase Ti_(50)Cu_(50)precursor exhibits a faster initial dealloying rate due to its homogeneous structure,yet complete dealloying requires 90 min.In contrast,the dualphase Ti_(30)Cu_(70)precursor achieves complete dealloying in 30 min,demonstrating the impact of a higher Cu concentration on accelerating the process kinetics.Additionally,the study explores the coarsening behavior and hardness variations during the LMD process,along with the microstructural characteristics of Mg-Ti composites fabricated from these two precursors.The findings highlight the critical role of precursor composition in tailoring the microstructure and properties of Mg-Ti composites produced through the LMD process,demonstrating its potential for advanced composite material manufacturing. 展开更多
关键词 Liquid metal dealloying Precursor composition Mg-Ti composite 3D interconnected structure HARDNESS
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Arsenic mobility and microbial community composition in the sediments of coastal wetlands driven by tidal action
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作者 Ting Luo Wei Qin +4 位作者 Yuzhong Wang Yan Sun Sheng Kong Yang Zou Weihao Liang 《Journal of Environmental Sciences》 2025年第7期99-108,共10页
Arsenic(As)pollution in coastal wetlands has been receiving growing attention.However,the exact mechanism of As mobility driven by tidal action is still not completely understood.The results reveal that lower total As... Arsenic(As)pollution in coastal wetlands has been receiving growing attention.However,the exact mechanism of As mobility driven by tidal action is still not completely understood.The results reveal that lower total As concentrations in solution were observed in the flood-ebb treatment(FE),with the highest concentration being 7.1μg/L,and As(V)was the predominant species.However,elevated levels of total As in solution were found in the flooded treatment(FL),with a maximum value of 14.5μg/L after 30 days,and As(III)was the predominant form.The results of dissolved organicmatter(DOM)suggest that in the early to mid-stages of the incubation,fulvic acid-like substances might be utilized by microorganisms as electron donors or shuttle bodies,facilitating the reductive release of As/Fe from sediments.Both flood-ebb and flooded treatments promoted the transformation of crystalline iron hydrous oxides-bound As into residual forms.However,prolonged flooded conditions more readily facilitated the formation of specific adsorption forms of As and the reduction of crystalline iron hydrous oxides-bound As,increasing As mobility.In addition,the flood-ebb tides have been found to increase the diversity ofmicrobial populations.The main microbial genera in the flood-ebb treatment included Salinimicrobium,Erythrobacter,Yangia,Sulfitobacter,and Marinobacter.Bacillus,Psychrobacter,and Yangia showed a significant correlation with As(V).In flooded treatment,Bacillus,Pseudomonas,and Geothermobacter played a major role in the reduction and release of As.This study significantly contributes to the current understanding of how As behaves in diverse natural environments. 展开更多
关键词 ARSENIC MOBILITY Coastal wetlands Tidal action Microbial composition
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Omnivore or Insectivore?Diet Composition in the Starred or Roughtail Rock Agama,Laudakia vulgaris(Squamata:Agamidae)
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作者 Mohammad A.ABU BAKER Sajeda J.JABER +2 位作者 Ahmad A.KATBEH-BADER Ahmad M.DISI Zuhair S.AMR 《Asian Herpetological Research》 2025年第3期314-317,共4页
Dear Editor,Life-history studies including dietary preferences and trophic interactions are essential for understanding community ecology in lizards(Pianka,1986).The family Agamidae is one of the largest in terms of s... Dear Editor,Life-history studies including dietary preferences and trophic interactions are essential for understanding community ecology in lizards(Pianka,1986).The family Agamidae is one of the largest in terms of species diversity and occurs in a variety of habitats(Uetz et al.,2024). 展开更多
关键词 trophic interactions diet composition Laudakia vulgaris rock agama community ecology INSECTIVORE OMNIVORE dietary preferences
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Trends in alpha diversity,community composition,and network complexity of rare,intermediate,and abundant bacterial taxa along a latitudinal gradient and their impact on ecosystem multifunctionality
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作者 Rong Tang Shuaifeng Li +3 位作者 Xiaobo Huang Rui Zhang Cong Li Jianrong Su 《Forest Ecosystems》 2025年第4期642-654,共13页
Soil microbial communities are key factors in maintaining ecosystem multifunctionality(EMF).However,the distribution patterns of bacterial diversity and how the different bacterial taxa and their diversity dimensions ... Soil microbial communities are key factors in maintaining ecosystem multifunctionality(EMF).However,the distribution patterns of bacterial diversity and how the different bacterial taxa and their diversity dimensions affect EMF remain largely unknown.Here,we investigated variation in three measures of diversity(alpha diversity,community composition and network complexity)among rare,intermediate,and abundant taxa across a latitudinal gradient spanning five forest plots in Yunnan Province,China and examined their contributions on EMF.We aimed to characterize the diversity distributions of bacterial groups across latitudes and to assess the differences in the mechanisms underlying their contributions to EMF.We found that multifaceted diversity(i.e.,diversity assessed by the three different metrics)of rare,intermediate,and abundant bacteria generally decreased with increasing latitude.More importantly,we found that rare bacterial taxa tended to be more diverse,but they contributed less to EMF than intermediate or abundant bacteria.Among the three dimensions of diversity we assessed,only community composition significantly affected EMF across all locations,while alpha diversity had a negative effect,and network complexity showed no significant impact.Our study further emphasizes the importance of intermediate and abundant bacterial taxa as well as community composition to EMF and provides a theoretical basis for investigating the mechanisms by which belowground microorganisms drive EMF along a latitudinal gradient. 展开更多
关键词 BACTERIA Ecosystem multifunctionality Alpha diversity Community composition Network complexity Latitudinal gradient
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Unintentional emissions of polychlorinated naphthalenes in China:Sources,composition,and historical trends
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作者 Ye Huang Lin Huang +14 位作者 Ying Li Nazupar Sidikjan Yunshan Zhang Yan Chen Yangmin Chen Ye Li Wei Du Long Chen YanWu Shanshan Zhang Jing Yang Wenjun Meng Guofeng Shen Min Liu Shu Tao 《Journal of Environmental Sciences》 2025年第2期221-229,共9页
Polychlorinated naphthalenes(PCNs)are detrimental to human health and the environment.With the commercial production of PCNs banned,unintentional releases have emerged as a significant environmental source.However,rel... Polychlorinated naphthalenes(PCNs)are detrimental to human health and the environment.With the commercial production of PCNs banned,unintentional releases have emerged as a significant environmental source.However,relevant information is still scarce.In this study,provincial emissions for eight PCNs homologues from 37 sources in the Chinese mainland during the period of 1960-2019 were estimated based on a source-specific and time-varying emission factor database.The results showed that the total PCNs emissions in 2019 reached 757.0 kg with Hebei ranked at the top among all the provinces and iron&steel industry as the biggest source.Low-chlorinated PCNs comprised 90%of emissions by mass,while highly chlorinated PCNs dominated in terms of toxicity,highlighting divergent priorities for mitigating emissions and safeguarding human health.The emissions showed an overall upward trend from 1960 to 2019 driven by emission increase from iron&steel industry in terms of source,and from North China and East China in terms of geographic area.Per-capita emissions followed an inverted U-shaped environmental Kuznets curvewhile emission intensities decreased with increasing per-capita Gross Domestic Product(GDP)following a nearly linear pattern when log-transformed. 展开更多
关键词 PCNS Emission inventory Emission factor composition profile Emission intensity Chinese mainland
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Longitudinal changes in body composition during palliative systemic chemotherapy and survival outcomes in metastatic colorectal cancer
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作者 Hyehyun Jeong Yousun Ko +6 位作者 Kyung Won Kim Ji Sung Lee Seyoung Seo Sun Young Kim Yong Sang Hong Jeong Eun Kim Tae Won Kim 《World Journal of Gastrointestinal Oncology》 2025年第5期134-147,共14页
BACKGROUND In patients with metastatic colorectal cancer,chemotherapy may lead to changes in body composition,including skeletal muscle quantity and quality,and body fat area and distribution.Longitudinal follow-up da... BACKGROUND In patients with metastatic colorectal cancer,chemotherapy may lead to changes in body composition,including skeletal muscle quantity and quality,and body fat area and distribution.Longitudinal follow-up data in a homogeneous population are required to understand these changes better.AIM To comprehensively evaluate changes in body composition and their prognostic value in patients with metastatic colorectal cancer undergoing palliative chemo-therapy.METHODS This retrospective study included patients with recurrent or metastatic colorectal cancer who received palliative chemotherapy between 2008 and 2017.Computed tomography scans were analyzed at multiple time points(before each new chemotherapy regimen and after discontinuing all chemotherapy).Body composition was analyzed from each scan using artificial intelligence software(AID-UTM,iAID Inc.),and its association with survival was evaluated through time-dependent Cox regression to adjust for time-varying effects.RESULTS This analysis included 1805 patients,with a median age at diagnosis of 57 years,and 62%were male.At first-line chemotherapy initiation,4.7%,30.9%,36.5%,and 37.1%of the patients had sarcopenia,myosteatosis,and visceral and subcutaneous obesity,respectively.During treatment,approximately 54.5%of the patients experienced significant changes in body composition,with 9.1%and 19.2%developing new sarcopenia and myosteatosis,respectively.Sarcopenia and myosteatosis were associated with poorer survival outcomes[hazard ratio(HR)for sarcopenia,2.55(95%CI:2.06-3.16,P<0.001;HR for myosteatosis,2.37(95%CI:2.00-2.82),P<0.001].In contrast,visceral and subcutaneous obesity were associated with improved survival[HR for visceral obesity,0.69(95%CI:0.57-0.82),P<0.001;HR for subcutaneous obesity,0.78(95%CI:0.64-0.95),P=0.015],with no negative impacts observed at higher fat levels.These changes correlated with end-of-life survival time.CONCLUSION Abnormalities and body composition changes were frequently observed during palliative chemotherapy for advanced colorectal cancer;myosteatosis was common.Comprehensive body composition assessment offers valuable prognostic insights without requiring additional testing. 展开更多
关键词 SARCOPENIA Myosteatosis OBESITY Body composition Metastatic colorectal cancer Palliative systemic treatment CHEMOTHERAPY Deep learning Artificial intelligence
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Advances in Crack Formation Mechanisms,Evaluation Models,and Compositional Strategies for Additively Manufactured Nickel-Based Superalloys
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作者 Huabo Wu Jialiao Zhou +4 位作者 Lan Huang Zi Wang Liming Tan Jin Lv Feng Liu 《Computer Modeling in Engineering & Sciences》 2025年第6期2675-2709,共35页
Nickel-based superalloys are indispensable for high-temperature engineering applications,yet their additive manufacturing(AM)is plagued by significant cracking defects.This review investigates crack failure mechanisms... Nickel-based superalloys are indispensable for high-temperature engineering applications,yet their additive manufacturing(AM)is plagued by significant cracking defects.This review investigates crack failure mechanisms in AM nickel-based superalloys,emphasizing methodologies to evaluate crack sensitivity and compositional design strategies to mitigate defects.Key crack types—solidification,liquation,solid-state,stress corrosion,fatigue,and creep-fatigue cracks—are analyzed,with focus on formation mechanisms driven by thermal gradients,solute segregation,and microstructural heterogeneities.Evaluation frameworks such as the Rappaz-Drezet-Gremaud(RDG)criterion,Solidification Cracking Index(SCI),and Strain Age Cracking(SAC)index are reviewed for predicting crack susceptibility through integration of thermodynamic parameters,solidification kinetics,and mechanical properties.Alloy compositional design strategies are presented,including optimization of strengthening elements(Al,Ti),grain boundary modifiers(B,Zr,Re),and impurity control(C,O),which suppress crack initiation and propagation via microstructure refinement and enhanced high-temperature resistance.Computational approaches,such as thermodynamically assisted design,high-throughput experimentation,and machine learning,are highlighted for decoding complex composition-structure-property relationships.Challenges in modeling multi-scale defect interactions and developing unified frameworks for manufacturing-and service-induced cracks are outlined.This review underscores the necessity of integrated computational-experimental strategies to advance reliable AM of nickel-based superalloys,providing insights for defect prediction,alloy optimization,and process control. 展开更多
关键词 Additive manufacturing nickel-based superalloys CRACKING failure mechanism composition design
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Geriatric health changes during the COVID-19 pandemic:impacts on body composition and vascular aging
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作者 Bo Min Kim Young Jin Tak +12 位作者 Jeong Gyu Lee Yu Hyeon Yi Seung-Hun Lee GyuLee Kim Young Jin Ra Sang Yeoup Lee Young Hye Cho Eun Ju Park Young In Lee Jung In Choi Sae Rom Lee Ryuk Jun Kwon Soo Min Son 《Journal of Geriatric Cardiology》 2025年第8期753-756,共4页
Coronavirus disease 2019(COVID-19)has had a substantial global health impact,with over 765 million confirmed cases and nearly 7 million deaths.[1]In South Korea,stringent lockdown policy heavily restricted the daily a... Coronavirus disease 2019(COVID-19)has had a substantial global health impact,with over 765 million confirmed cases and nearly 7 million deaths.[1]In South Korea,stringent lockdown policy heavily restricted the daily activities for over two years,resulting in widespread public health issues. 展开更多
关键词 geriatric health public health issues body composition vascular aging coronavirus disease COVID lockdown policy
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Exploring the Scientific Connotation of Gypsum in Baihu Decoction Compatibility with Heat-clearing Effect Based on Phase Composition
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作者 Yunyun Wang Zhengxian Zhang +2 位作者 Haotian Peng Huahui Zeng Xiangxiang Wu 《Chinese Medicine and Natural Products》 2025年第1期35-46,共12页
Objective This study aimed to study the effects of different crystalline states of Sheng Shigao(raw gypsum,RG)and its inorganic elements on the antipyretic efficacy of Baihu Decoction(BHT).Methods RG samples calcined ... Objective This study aimed to study the effects of different crystalline states of Sheng Shigao(raw gypsum,RG)and its inorganic elements on the antipyretic efficacy of Baihu Decoction(BHT).Methods RG samples calcined at different temperatures were prepared.The phase composition of RG and Duan Shigao(calcination of gypsum,CG)as well as the changes in phase composition before and after adding water to RG calcined at specific temperatures,were determined using X-ray diffraction(XRD).A fever model was established by subcutaneously injecting 20%yeast suspension(10 mL·kg~(-1))into the backs of rats.The effects of BHT containing RG in different crystalline states on rat body temperature were measured.Serum levels of IL-1β,IL-6,and hypothalamic prostaglandin E2(PGE_2)were detected using ELISA.Serum Ca~(2+)levels were measured using a microplate method.The content of trace elements in RG and CG and the corresponding freeze-dried BHT powder was determined using inductively coupled plasma mass spectrometry(ICP-MS).The complexation of representative inorganic elements with mangiferin,a major active component in BHT,was investigated using UV-Vis spectroscopy and fluorescence spectroscopy.A validation model was established using RAW264.7 mouse macrophages.Drug-containing serum of BHT with different inorganic elements was prepared,and the nitric oxide(NO)levels in the cell supernatant of different treatment groups were measured using the Griess method.The mRNA levels of IL-6,TNF-α,and PGE2in each group were detected using qPCR(real-time fluorescent quantitative PCR).Results After calcination,the phase composition of RG changed,and the content of inorganic elements in RG,CG170(RG calcined at 170°C),and CG350(RG calcined at 350°C)showed similar trends.Compared with RG,the content of Ca,Sr,Al,and Na in CG changed significantly.Compared with BHT,the content of Ca,Sr,Si,and Na in CG changed significantly when incorporated into the formula.Intermolecular interactions confirmed strong binding between mangiferin and Cu~(2+)and Al~(3+).Cu~(2+)and Fe~(3+)exhibited fluorescence quenching effects on mangiferin solution,while Al~(3+)and Zn~(2+)showed strong fluorescence enhancement,with fluorescence intensity increasing by 120-fold and 30-fold,respectively.In vitro evaluation of synergistic anti-inflammatory effects confirmed that Ca,Fe,Cr,Al,and Si exhibited synergistic anti-inflammatory effects.Conclusion The crystalline state of RG has little effect on its antipyretic properties,while Ca,Sr,Na,Fe,and Al are likely the key material bases influencing its efficacy. 展开更多
关键词 GYPSUM Baihu Decoction heat-clearing compatibility of medicines phase composition
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Droughts and windstorms due to climate change increase variability in species and trait composition of a subtropical monsoon evergreen broadleaf forest in China
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作者 Wenjing Chen Lei Liu +6 位作者 Daijun Liu Josep Penuelas Guoyi Zhou Zhen Yu Anchi Wu Zhurong Wu Langqin Hua 《Forest Ecosystems》 2025年第1期11-19,共9页
Background:Climate change is accelerating alterations in forest species and community composition worldwide,especially following extreme events like severe droughts and windstorms.Understanding these effects on subtro... Background:Climate change is accelerating alterations in forest species and community composition worldwide,especially following extreme events like severe droughts and windstorms.Understanding these effects on subtropical forests is crucial for conservation and forest management,but it remains unclear whether the impacts are stochastic or deterministic.Methods:We analyzed a unique dataset from a 1-ha permanent plot in a subtropical monsoon broadleaf evergreen forest in China,monitored over 26 years with six surveys from 1994 to 2020.The forest has been free from anthropogenic disturbances for over 400 years.In each survey,we measured all trees with a diameter at breast height(DBH)≥1 cm,and recorded 11 plant functional traits relating to photosynthesis,wood properties,water use,and nutrient dynamics.Using this data,we calculated species and trait dispersion,assessing short-term(~5years)and long-term(26 years)trends in species and trait composition following severe droughts and windstorm events.Results:Severe droughts,and subsequent droughts,increased both species and trait dispersion,while species composition converged,and trait dispersion remained relatively stable throughout the recovery period.Windstorm events led to increased species dispersion but decreased trait dispersion.We observed a clear directional shift in both species and trait composition under these climatic stressors,with a more pronounced increase in trait dispersion compared to species dispersion.Conclusion:In the short term(~5 years),severe droughts and windstorms increased species composition divergence,while trait composition responses varied.Over 26 years,deterministic processes mainly drove community composition changes,especially for trait composition,although stochastic processes also played a role.These findings suggest enhancing forest resilience to climatic stressors by protecting adaptive species or increasing species diversity in management practices. 展开更多
关键词 Community dynamics Functional traits Community composition Deterministic processes Climate change
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Composition design of gold-platinum alloy with ultra-low magnetic susceptibility:First-principles and experimental validation
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作者 Wei Wu Yanli Lu +5 位作者 Chenwei Zhai Lian Ouyang Wenqing Yang Rui Hu Yi Liu Quan Fu 《Journal of Materials Science & Technology》 2025年第8期62-71,共10页
Gold-platinum(Au-Pt)alloy has aroused considerable attention due to its ultra-low magnetic susceptibility(MS)in testing mass(TM)on spacecraft.However,the effect of Au content on the properties of the alloy has not yet... Gold-platinum(Au-Pt)alloy has aroused considerable attention due to its ultra-low magnetic susceptibility(MS)in testing mass(TM)on spacecraft.However,the effect of Au content on the properties of the alloy has not yet been understood.In this study,the composition design of Au-Pt alloy with ultra-low MS was achieved through density functional theory(DFT)and experimental methods.The elastic,thermal properties and electronic structure were systematically investigated,the composition range was further optimized and Au75Pt25 was determined to be the most suitable alloy for TM material.The phase composition of this alloy after cold rolling and solid solution was characterized,indicating a single-phase FCC structure.In addition,there is a good validation between the experimental Vickers hardness and the DFT results.This work provides new insights into the compositional optimization of Au-Pt alloys and lays the foundation for alloy development. 展开更多
关键词 Au-Pt alloy Ultra-low magnetic susceptibility composition design First principles HAADF-STEM
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The chemical composition, quality control and pharmacological effects of Gualou-Xiebai-Banxia Decoction: a review
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作者 Yan-Tao Wang Yin-Yan Lai +4 位作者 Li Wang Xiao-Li Zheng Hong-Ju Li Su-Hong Chen Zheng Xiang 《Traditional Medicine Research》 2025年第4期72-82,共11页
Gualou-Xiebai-Banxia Decoction(GXBD)is a traditional Chinese herbal formula including four traditional Chinese medicines:Gualou(Trichosanthis Fructus,TF),Xiebai(Allii Macrostemonis Bulbus,AMB),Banxia(Pinelliae Rhizoma... Gualou-Xiebai-Banxia Decoction(GXBD)is a traditional Chinese herbal formula including four traditional Chinese medicines:Gualou(Trichosanthis Fructus,TF),Xiebai(Allii Macrostemonis Bulbus,AMB),Banxia(Pinelliae Rhizoma,PR)and yellow wine.It is a classical therapy for chest stuffiness and pain syndrome and is widely used in the clinical treatment of coronary heart disease.It also shows significant therapeutic effects on pulmonary heart disease,hyperlipidemia,and arrhythmia.This study conducted a literature review and collected information on GXBD from databases such as PubMed,Web of Science,China National Knowledge Infrastructure,and ScienceDirect.The result indicated that the main active ingredients of GXBD are steroids,flavonoids,terpenoids,alkaloids,amino acids,and organic acids.Trigonelline,macrostemonoside and cucurbitacin B can provide reference for its quality control.GXBD may exert therapeutic effects on coronary heart disease through AMPK,PI3K-AKT,oxLDL,VEGF,and NF-κB signal pathways.This review provides a comprehensive analysis and summary of the chemical composition and in vivo metabolism of three traditional Chinese medicines(TF,AMB,and PR),along with an evaluation of the chemical composition,quality control,pharmacological effects,and clinical application of GXBD.Based on these,areas requiring further research on GXBD have been proposed to provide a reference for its further development and new drug research. 展开更多
关键词 Gualou-Xiebai-Banxia Decoction chemical composition chest stuffiness quality control pharmacological mechanism
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