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不同云种类地表云短波辐射效应的主控因子及其不确定性研究——以美国南部大平原地区中心观测站为例
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作者 刘唯佳 韩永翔 +1 位作者 周鑫 李嘉欣 《大气科学学报》 北大核心 2025年第5期736-751,共16页
地表的云短波辐射效应(shortwave cloud radiative effect,F_(CRE))在气候变化中扮演关键角色,但在不同的云种类下具有很大的不确定性且其主控因子不明。本文利用美国南部大平原中心站14年15 min分辨率的云种类和同期地表短波辐照度等... 地表的云短波辐射效应(shortwave cloud radiative effect,F_(CRE))在气候变化中扮演关键角色,但在不同的云种类下具有很大的不确定性且其主控因子不明。本文利用美国南部大平原中心站14年15 min分辨率的云种类和同期地表短波辐照度等观测资料,分析了8种云(淡积云Cu、层云St、高积云Ac、高层云As、卷层云Cs、卷云Ci、浓积云Co、深对流云Dc)的F_(CRE)特征及其影响因素,引入云相对辐射效应(relative F_(CRE),F_(RCRE))参量,结合XGBoost及SHAP模型揭示了不同云种类下两种云辐射效应指标的差异及主控因子,并评估了二者的不确定性。结果表明:1)虽然8种云的F_(CRE)强度总体上与云量、云反照率呈正相关关系,与天顶角呈反相关关系,但其细节却显示不同云种类的云参量与F_(CRE)存在复杂的非线性关系。2)在95%置信区间内,云量和云反照率双低的Cu、Ac和Ci的F_(CRE)波幅为-350~206 W·m^(-2),云量和反照率双高的Co和Dc为-1172~289 W·m^(-2),其他具有中等云属性的St、Cs和As为-926~371 W·m^(-2),这表明不同云种类的F_(CRE)不确定性很大。F_(CRE)受云参量、辐射参量和天顶角的影响,其主控因子达5~6个,且因子不一是其不确定性大的重要原因。3)引入的F_(RCRE)本质上同F_(CRE)所反映的云辐射特征一致,但其主控因子仅稳定剩下云量、云反照率和直接辐照度3个,分离了天顶角对它的影响。8种云的F_(RCRE)较F_(CRE)的不确定性降低了2.6%~66.0%,平均下降了10.7%,其中强对流性云Co和Dc下降最为显著。4)对于云量和云反照率双高的Co和Dc,云反照率对F_(RCRE)的调制作用更为显著,反之,云量和云反照率双低的Cu、Ac和Ci,云量的调制作用更加显著。该研究为深入理解云-辐射相互作用、降低气候模拟中云辐射效应的不确定性提供了新的思路。 展开更多
关键词 短波云辐射效应 云种类 主控因子 不确定性分析 可解释性机器学习模型
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土壤团聚体有机碳固存效应研究进展
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作者 董艳梅 于晟玥 +10 位作者 张昊鑫 荆勇 樊秉乾 雷秋良 杜新忠 贾倍倍 王则玉 蒲胜海 武淑霞 安妙颖 刘宏斌 《中国土壤与肥料》 北大核心 2025年第8期248-258,共11页
土壤有机碳是陆地生态系统碳库的重要组成部分,对维持土壤肥力、促进农业可持续发展以及应对全球气候变化具有重要意义。团聚体作为土壤有机碳的重要载体,为有机碳的固存提供了储存空间。土壤有机碳的固存又进一步促进团聚体的形成、稳... 土壤有机碳是陆地生态系统碳库的重要组成部分,对维持土壤肥力、促进农业可持续发展以及应对全球气候变化具有重要意义。团聚体作为土壤有机碳的重要载体,为有机碳的固存提供了储存空间。土壤有机碳的固存又进一步促进团聚体的形成、稳定及周转,改善土壤结构、提升土壤质量。目前,在土壤团聚体固碳机理领域已有大量研究,但对参与土壤团聚体有机碳固存的生物因素和非生物因素的作用机制尚缺乏系统性总结。本文系统梳理了国内外土壤团聚体中有机碳来源和组成的发展历程,综述了土壤团聚体对有机碳的固存机制,并讨论了土壤水分、温度、土壤类型、施肥、秸秆还田及耕作方式等因素对土壤团聚体有机碳固持的影响。最后,本文展望了土壤团聚体有机碳固存机制研究的发展方向,旨在全面认识土壤团聚体碳固存机制,为优化土地管理策略、提升土壤质量及应对全球气候变化提供科学依据。 展开更多
关键词 土壤有机碳 团聚体 土壤结构 碳固存 影响因素
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Distribution,species richness,and relative importance of different plant life forms across drylands in China 被引量:1
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作者 Shuran Yao Weigang Hu +16 位作者 Mingfei Ji Abraham Allan Degen Qiajun Du Muhammad Adnan Akram Yuan Sun Ying Sun Yan Deng Longwei Dong Haiyang Gong Qingqing Hou Shubin Xie Xiaoting Wang Jinzhi Ran Bernhard Schmid Qinfeng Guo Karl J.Niklas Jianming Deng 《Plant Diversity》 2025年第2期273-281,共9页
Studies on plant diversity are usually based on the total number of species in a community.However,few studies have examined species richness(SR)of different plant life forms in a community along largescale environmen... Studies on plant diversity are usually based on the total number of species in a community.However,few studies have examined species richness(SR)of different plant life forms in a community along largescale environmental gradients.Particularly,the relative importance(RIV)of different plant life forms in a community and how they vary with environmental variables are still unclear.To fill these gaps,we determined plant diversity of ephemeral plants,annual herbs,perennial herbs,and woody plants from 187 sites across drylands in China.The SR patterns of herbaceous plants,especially perennial herbs,and their RIV in plant communities increased with increasing precipitation and soil nutrient content;however,the RIV of annual herbs was not altered along these gradients.The SR and RIV of ephemeral plants were affected mainly by precipitation seasonality.The SR of woody plants had a unimodal relationship with air temperature and exhibited the highest RIV and SR percentage in plant communities under the harshest environments.An obvious shift emerged in plant community composition,SR and their critical impact factors at 238.5 mm of mean annual precipitation(MAP).In mesic regions(>238.5 mm),herbs were the dominant species,and the SR displayed a relatively slow decreasing rate with increasing aridity,which was mediated mainly by MAP and soil nutrients.In arid regions(<238.5 mm),woody plants were the dominant species,and the SR displayed a relatively fast decreasing rate with increasing aridity,which was mediated mainly by climate variables,especially precipitation.Our findings highlight the importance of comparative life form studies in community structure and biodiversity,as their responses to gradients differed substantially on a large scale. 展开更多
关键词 DRYLANDS Environmental gradients Plant life forms Relative importance Species richness THRESHOLD
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Window to the soul:Pupil dynamics unveil the consolidation of recent and remote memories
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作者 Hongyu Chang Wenbo Tang 《Zoological Research》 2025年第2期261-262,共2页
Memory enables organisms to encode,store,and retrieve information essential for interacting with and adapting to a dynamic environment.As an internal representation of the external world,memory serves as a crucial bri... Memory enables organisms to encode,store,and retrieve information essential for interacting with and adapting to a dynamic environment.As an internal representation of the external world,memory serves as a crucial bridge between past experiences and future behaviors.However,the brain continuously forms new memories,raising the question of how new memories are integrated without disrupting previously formed ones. 展开更多
关键词 recent memories previously formed ones memory brain interacting adapting CONSOLIDATION remote memories pupil dynamics
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An Explainable Autoencoder-Based Feature Extraction Combined with CNN-LSTM-PSO Model for Improved Predictive Maintenance
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作者 Ishaani Priyadarshini 《Computers, Materials & Continua》 2025年第4期635-659,共25页
Predictive maintenance plays a crucial role in preventing equipment failures and minimizing operational downtime in modern industries.However,traditional predictive maintenance methods often face challenges in adaptin... Predictive maintenance plays a crucial role in preventing equipment failures and minimizing operational downtime in modern industries.However,traditional predictive maintenance methods often face challenges in adapting to diverse industrial environments and ensuring the transparency and fairness of their predictions.This paper presents a novel predictive maintenance framework that integrates deep learning and optimization techniques while addressing key ethical considerations,such as transparency,fairness,and explainability,in artificial intelligence driven decision-making.The framework employs an Autoencoder for feature reduction,a Convolutional Neural Network for pattern recognition,and a Long Short-Term Memory network for temporal analysis.To enhance transparency,the decision-making process of the framework is made interpretable,allowing stakeholders to understand and trust the model’s predictions.Additionally,Particle Swarm Optimization is used to refine hyperparameters for optimal performance and mitigate potential biases in the model.Experiments are conducted on multiple datasets from different industrial scenarios,with performance validated using accuracy,precision,recall,F1-score,and training time metrics.The results demonstrate an impressive accuracy of up to 99.92%and 99.45%across different datasets,highlighting the framework’s effectiveness in enhancing predictive maintenance strategies.Furthermore,the model’s explainability ensures that the decisions can be audited for fairness and accountability,aligning with ethical standards for critical systems.By addressing transparency and reducing potential biases,this framework contributes to the responsible and trustworthy deployment of artificial intelligence in industrial environments,particularly in safety-critical applications.The results underscore its potential for wide application across various industrial contexts,enhancing both performance and ethical decision-making. 展开更多
关键词 Explainability feature reduction predictive maintenance OPTIMIZATION
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Enhancement of quality of Glycyrrhiza uralensis Fisch.through chitosan induction for use as medicine and food:Insights from metabolomics and proteomics
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作者 Yingquan Kang Guangxi Ren +6 位作者 Li Wang Dan Jiang Qingyi Xu Jiayang Zhang Zhenfang Bai Mingqing Chang Chunsheng Liu 《Journal of Traditional Chinese Medical Sciences》 2025年第2期175-190,共16页
Objective:To explore the impact of exogenous chitosan on the growth and metabolism of Glycyrrhiza uralensis Fisch.(G.uralensis)and to improve the quality of cultivated G.uralensis for both medicine and food and aid in... Objective:To explore the impact of exogenous chitosan on the growth and metabolism of Glycyrrhiza uralensis Fisch.(G.uralensis)and to improve the quality of cultivated G.uralensis for both medicine and food and aid in the increase in the content of effective components in G.uralensis.Methods:In this study,whole G.uralensis plants were treated with exogenous chitosan,and compre-hensive analyses of secondary metabolites and proteins were conducted using liquid chromatography with tandem mass spectrometry and isobaric tag for relative and absolute quantitation,respectively.Effects of chitosan induction on endogenous hormones of G.uralensis were analyzed using an enzyme-linked immunosorbent assay.Gene ontology function annotation and Kyoto Encyclopedia of Genes and Genomes pathway annotation were conducted to study the effect of chitosan induction on the proteome.Results:Chitosan induction significantly increased the levels of flavonoids in G.uralensis;however,the variation in triterpenoids was not substantial.Biological processes,including photosynthesis,secondary metabolism,and abiotic stress responses,were significantly enriched.Additionally,the photosynthetic pathway,photosynthesis-antenna protein pathway,and plant hormone signal transduction pathway were significantly enriched.In the flavonoid biosynthesis pathway,the upstream-related enzyme phenylalanine ammonia-lyase(PAL)and the downstream-related enzymes chalcone synthase(CHS),polyketide reductase(PKR),chalcone isomerase(CHI),and vestitone reductase(VR)were significantly upregulated.Conclusions:Our findings suggest that chitosan induction may promote the tricarboxylic acid(TCA)cycle,and the TCA cycle enhancement significantly upregulated PAL,CHS,PKR,CHI,and VR,the five key enzymes involved in flavonoid synthesis of G.uralensis,indicating that chitosan induction activated the entire metabolic pathway associated with flavonoids in G.uralensis.Our findings provide a reference for improving the quality of cultivated G.uralensis from the perspective of pharmacodynamic components. 展开更多
关键词 Glycyrrhizae Radix et Rhizoma CHITOSAN Metabolomics PROTEOMICS
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Relocation for improved ecosystem service and human wellbeing?Evidence from Fuping,Hebei,China
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作者 WU Pengxin LIU Mingyao +7 位作者 ZHENG Mingze LIAO Chuan HUA Xiaobo FEI Ding BAI Yansong ZHOU Yuchen ZHOU Yihan HUANG Qingxu 《Journal of Geographical Sciences》 2025年第7期1556-1574,共19页
Migration is a potential strategy to reduce poverty in the Global South.In China,the Poverty-alleviation Relocation(PAR)is a government-led,large-scale migration initiative aimed at eliminating poverty and promoting e... Migration is a potential strategy to reduce poverty in the Global South.In China,the Poverty-alleviation Relocation(PAR)is a government-led,large-scale migration initiative aimed at eliminating poverty and promoting environmental sustainability.To examine the ecological and socio-economic effects of the PAR,we quantified the changes in five types of ecosystem services(ES)as well as the subjective well-being of rural residents in Fuping county,Hebei province of China,by using ES mapping,household survey,and semi-structured interviews.We found that the PAR improves people's quality of life,with the well-being scores associated with transportation,communication,education,and healthcare increasing by 0.45–0.81.Additionally,the PAR enhances the supply of ES,evidenced by the increases in four types of ES in both in-migration and out-migration areas.The ES growth rates in in-migration areas ranged from 0.7%to 3.9%,while in out-migration areas,the rates ranged from 0.4%to 2.5%.However,the changes in income and food well-being are minimal,with scores at 0 and 0.32,respectively.More importantly,the elderly and low-educated residents experience minimal improvements in well-being after relocation.Our findings suggest that for other developing countries seeking to adopt PAR,it is crucial to provide targeted support for livelihood transitions,particularly for marginalized social groups,restore out-migration areas,and strengthen cross-regional cooperation to better address ecological constraints on livelihoods. 展开更多
关键词 ecosystem services land use rural sustainability subjective wellbeing social-ecological system URBANIZATION
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Environmentally friendly tailor-made oleo-dispersions of electrospun cellulose acetate propionate nanostructures in castor oil for lubricant applications
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作者 M.A.Martín-Alfonso J.F.Rubio-Valle +2 位作者 J.P.Hinestroza J.E.Martín-Alfonso J.M.Franco 《Nano Materials Science》 2025年第1期90-104,共15页
The aim of this work is to find an alternative lubricating grease formulation that can be produced from renewable and biodegradable sources with minimal risks to human health and the environment.We used a castor oil a... The aim of this work is to find an alternative lubricating grease formulation that can be produced from renewable and biodegradable sources with minimal risks to human health and the environment.We used a castor oil and electrospun cellulose acetate propionate(CAp)as raw materials.We hypothesized that the acetyl and propionyl groups could provide an adequate chemical compatibility with the castor oil and that the electrospun nanostructures could enable improved physical stability by creating a variety of morphologies allowing the tailoring of the rheological and tribological properties of the resulting greases.The experimental results show that the use of electrospun CAp nanostructures can indeed yield physically stable formulations,even when used at low concentrations(3 wt%).The resulting dispersions went through structural transitions due to changes in the thickener morphologies and/or concentration,as shown by oscillatory rheology,oil holding capacity,tackiness,and lubrication performance in metal–metal contact.We found that the formulations,containing smooth or porous CAp nanofibers,at 5 wt%as a thickener,possess suitable rheological and tribological properties with a performance comparable to that of traditional lithium lubricating greases. 展开更多
关键词 Cleaner products Green lubricants NANOFIBERS Rheology TRIBOLOGY
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Fatigue and deformation mechanisms of ultrasonic spot-welded dissimilar joints of a magnesium alloy to a clad aluminum alloy 被引量:1
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作者 Soumya Sobhan Dash Rylan Christopher Fernandes +7 位作者 Xiao Shang Yu Zou He Peng Xianquan Jiang Xiangfan Fang Ninshu Ma Dongyang Li Daolun Chen 《Journal of Magnesium and Alloys》 2025年第5期1939-1952,共14页
A low rare-earth containing ZEK100-O magnesium alloy was welded to AA1230-clad high-strength AA2024-T3 aluminum alloy via solidstate ultrasonic spot welding(USW)to evaluate the microstructure,tensile lap shear strengt... A low rare-earth containing ZEK100-O magnesium alloy was welded to AA1230-clad high-strength AA2024-T3 aluminum alloy via solidstate ultrasonic spot welding(USW)to evaluate the microstructure,tensile lap shear strength,and fatigue properties.The tensile strength increased with increasing welding energy,peaked at a welding energy of 1000 J,and then decreased due to the formation of an increasingly thick diffusion layer mainly containing Al12Mg17intermetallic compound at higher energy levels.The peak tensile lap shear strength attained at 1000 J was attributed to the optimal inter-diffusion between the magnesium alloy and softer AA1230-clad Al layer along with the presence of‘fishhook'-like mechanical interlocks at the weld interface and the formation of an indistinguishable intermetallic layer.The dissimilar joints welded at 1000 J also exhibited a longer fatigue life than other Mg-Al dissimilar joints,suggesting the beneficial role of the softer clad layer with a better intermingling capacity during USW.While the transverse-through-thickness(TTT)failure mode prevailed at lower cyclic loading levels,interfacial failure was the predominant mode of fatigue failure at higher cyclic loads,where distinctive fatigue striations were also observed on the fracture surface of the softer clad Al layer.This was associated with the presence of opening stress and bending moment near the nugget edge despite the tension-tension lap shear cyclic loading applied. 展开更多
关键词 Ultrasonic spot welding Magnesium alloy Clad aluminum alloy Tensile lap shear strength Fatigue life
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Secure Malicious Node Detection in Decentralized Healthcare Networks Using Cloud and Edge Computing with Blockchain-Enabled Federated Learning
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作者 Raj Sonani Reham Alhejaili +2 位作者 Pushpalika Chatterjee Khalid Hamad Alnafisah Jehad Ali 《Computer Modeling in Engineering & Sciences》 2025年第9期3169-3189,共21页
Healthcare networks are transitioning from manual records to electronic health records,but this shift introduces vulnerabilities such as secure communication issues,privacy concerns,and the presence of malicious nodes... Healthcare networks are transitioning from manual records to electronic health records,but this shift introduces vulnerabilities such as secure communication issues,privacy concerns,and the presence of malicious nodes.Existing machine and deep learning-based anomalies detection methods often rely on centralized training,leading to reduced accuracy and potential privacy breaches.Therefore,this study proposes a Blockchain-based-Federated Learning architecture for Malicious Node Detection(BFL-MND)model.It trains models locally within healthcare clusters,sharing only model updates instead of patient data,preserving privacy and improving accuracy.Cloud and edge computing enhance the model’s scalability,while blockchain ensures secure,tamper-proof access to health data.Using the PhysioNet dataset,the proposed model achieves an accuracy of 0.95,F1 score of 0.93,precision of 0.94,and recall of 0.96,outperforming baseline models like random forest(0.88),adaptive boosting(0.90),logistic regression(0.86),perceptron(0.83),and deep neural networks(0.92). 展开更多
关键词 Authentication blockchain deep learning federated learning healthcare network machine learning wearable sensor nodes
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Foliar resorption of beech and maple along an elevation gradient in a northern hardwood forest
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作者 Timothy J.Fahey Natalie L.Cleavitt +4 位作者 Pamela H.Templer Peter M.Groffman Amey S.Bailey Stephen B.Caron Geoffrey Wilson 《Forest Ecosystems》 2025年第3期505-513,共9页
Foliar resorption is a principal nutrient conservation mechanism in terrestrial vegetation that could be sensitive to ongoing changes in climate and atmospheric nitrogen(N)deposition.We quantified N resorption in nort... Foliar resorption is a principal nutrient conservation mechanism in terrestrial vegetation that could be sensitive to ongoing changes in climate and atmospheric nitrogen(N)deposition.We quantified N resorption in northern hardwood forests along an elevation gradient of decreasing temperature and increasing soil N availability to evaluate how this critical nutrient cycling process can be expected to respond to global and regional environmental changes.Foliar N resorption proficiency(NRP)increased significantly at lower elevations for both sugar maple and American beech,the dominant species in these forests.Foliar N resorption efficiency(NRE)also decreased with increasing elevation,but only in one year.Both species exhibited strong negative relationships between NRP and soil N availability.Thus,we anticipate that with climate warming and decreasing N inputs,northern hardwood forests can be expected to exhibit stronger N conservation via foliar resorption.Both species also exhibited strong correlations between resorption efficiency of N and C,but resorption of both elements was much greater for beech than sugar maple,suggesting contrasting mechanisms of nutrient conservation between these two widespread species. 展开更多
关键词 Acer saccharum Fagus grandifolia CLIMATE Leaf nutrients Soil nitrogen
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Feeding rumen-protected choline during the periconceptional period programs postnatal phenotype of suckled beef calves
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作者 Masroor Sagheer McKenzie L.J.Haimon +9 位作者 Samuel Hincapie Montoya Daniella Heredia Federico Tarnonsky Mauro E.Venturini Angella Gonella-Diaza Nicolas DiLorenzo Joseph W.McFadden Gabriela Dalmaso de Melo Ky G.Pohler Peter J.Hansen 《Journal of Animal Science and Biotechnology》 2025年第4期1696-1703,共8页
Background Supplementation of choline chloride in culture medium programs the preimplantation bovine embryo to increase weaning weight of the resultant calf.Here,it was hypothesized that similar programming actions of... Background Supplementation of choline chloride in culture medium programs the preimplantation bovine embryo to increase weaning weight of the resultant calf.Here,it was hypothesized that similar programming actions of choline can be induced by feeding rumen-protected choline(RPC)to beef cows during the periconceptional period.Results A preliminary experiment was conducted to determine changes in circulating concentrations of choline and its metabolites after RPC supplementation.Suckled beef cows were individually fed 0,30,60,and 90 g of RPC(i.e.,0,8.6,17.3 and 25.9 g choline chloride)and blood samples were collected at random times after feeding.There were no differences in plasma concentrations of choline or its metabolites between groups.In the second experiment,effects of feeding 60 g/d RPC from d-1 to 7 relative to timed artificial insemination were examined for suckled beef cows.Feeding RPC did not affect pregnancy or calving rates,pregnancy losses,plasma concentrations of pregnancy-associated glycoproteins,gestation length or calf birth weight.Calves from RPC fed dams were lighter than control calves at~118 days of age(range 75–150;age included in the statistical model)and at weaning at~248 days of age.There was no effect of treatment on hip height at~118 days of age although there was a trend for RPC calves to be shorter at weaning.Weight/height ratio was lower for RPC than control at both 118 and 248 days of age.Treatment did not affect testis weight at~118 days of age.Conclusions Supplementation of RPC during the periconceptional period programmed development to alter calf phenotype in the postnatal period.The net result,reduced body weight,was the opposite of the phenotype caused by the addition of choline to embryo culture medium. 展开更多
关键词 Beef cattle CHOLINE PREGNANCY PROGRAMMING
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Large herbivores increase the proportion of palatable species rather than unpalatable species in the plant community
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作者 Yu Li Shikui Dong +7 位作者 Qingzhu Gao Yong Zhang Hasbagan Ganjurjav Guozheng Hu Xuexia Wang Yulong Yan Fengcai He Fangyan Cheng 《Journal of Integrative Agriculture》 2025年第3期859-870,共12页
When the dominant species in a plant community are palatable,many believe that large herbivores will reduce the dominant species and promote the proportion of previously suppressed species.However,this view may not al... When the dominant species in a plant community are palatable,many believe that large herbivores will reduce the dominant species and promote the proportion of previously suppressed species.However,this view may not always hold true.We conducted a 4-year yak grazing experiment on the Qinghai-Tibet Plateau and tracked the plant compositions of the rotational grazing(RG)and grazing exclusion(GE)grasslands during the four years.The results showed that in the absence of yaks under GE,the plant community was dominated by two palatable species,Kobresia pygmaea and Stipa capillata,due to their small leaf area and rapid growth strategy.The presence of yaks under RG significantly inhibited S.capillata and over half of the forbs,while the proportion of K.pygmaea increased and it became the absolute dominant species,contradicting the view that large herbivores inhibit palatable species.Interannually,the dominance of K.pygmaea under RG decreased in the dry year,leading to an increase in the dominance of the other eight species.Under GE,the dominance of K.pygmaea declined notably in the dry year,while S.capillata and seven other forbs increased substantially.Overall,these results suggest that K.pygmaea is grazing-tolerant but not drought-tolerant,whereas the other eight species are drought-tolerant but not grazingtolerant.At the community level,community composition shifts resulting from succession after grazing exclusion exceeded those caused by drought,drought tends to induce community species turnover while grazing tends to induce species abundance variations.In summary,our conclusions remind ranch managers that when considering the impact of livestock on plant community composition,they should factor in local conditions and climate change rather than simply assuming that livestock will suppress the palatable species. 展开更多
关键词 GRAZING drought community composition SUCCESSION Qinghai-Tibet Plateau
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Effects of exercise on inflammation,circulating tumor cells,and circulating tumor DNA in colorectal cancer
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作者 Justin C.Brown Stephanie L.E.Compton +6 位作者 Andrew Kang Anjana Jayaraman LAnne Gilmore Brian J.Kirby Frank L.Greenway Shengping Yang Guillaume Spielmann 《Journal of Sport and Health Science》 2025年第6期33-41,166,共10页
Background The biological mechanisms by which postdiagnosis physical activity improves disease-free survival in colorectal cancer survivors remain incompletely understood.This trial tested the hypothesis that 12 weeks... Background The biological mechanisms by which postdiagnosis physical activity improves disease-free survival in colorectal cancer survivors remain incompletely understood.This trial tested the hypothesis that 12 weeks of moderate-intensity aerobic exercise,when compared with a control group,would change inflammation,circulating tumor cells(CTCs),and circulating tumor DNA(ctDNA)in a manner consistent with an improved cancer prognosis.Methods This trial randomized Stages I–III colorectal cancer survivors to 12 weeks of home-based moderate-intensity aerobic exercise or a waitlist control group.The co-primary endpoints were high-sensitivity C-reactive protein(hs-CRP)and interleukin-6(IL-6),secondary endpoints were soluble tumor necrosis factor-αreceptor 2(sTNFαR2)and CTCs,and the exploratory endpoint was tumor fraction quantified from ctDNA.Results Sixty subjects were randomized(age=60.6±10.8 years,mean±SD;39(65%)females;46(77%)colonic primary tumor),and 59(98%)subjects completed the study.Over 12 weeks,exercise adherence was 92%(95%confidence interval(95%CI):86‒99).Exercise improved submaximal fitness capacity(0.36 metabolic equivalents;95%CI:0.05‒0.67;p=0.025)and objectively measured moderate-to-vigorous-intensity physical activity(34.8%,95%CI:11.3‒63.1;p=0.002)compared to control.Exercise did not change hs-CRP(20.9%,95%CI:−17.1 to 76.2;p=0.32),IL-6(11.4%,95%CI:−7.5 to 34.0;p=0.25),or sTNFαR2(−3.6%,95%CI:−13.7 to 7.7;p=0.52)compared to control.In the subgroup of subjects with elevated baseline hs-CRP(n=35,58.3%),aerobic exercise reduced hs-CRP(−35.5%,95%CI:−55.3 to−3.8;p=0.031).Exercise did not change CTCs(0.59 cells/mL,95%CI:−0.33 to 1.51;p=0.21)or tumor fraction(0.0005,95%CI:−0.0024 to 0.0034;p=0.73).In exploratory analyses,higher aerobic exercise adherence correlated with a reduction in CTCs(ρ=−0.37,95%CI:−0.66 to−0.08;p=0.013).Conclusion Colorectal cancer survivors achieved high adherence to a home-based moderate-intensity aerobic exercise prescription that improved fitness capacity and physical activity but did not reduce inflammation or change tumor endpoints from a liquid biopsy. 展开更多
关键词 Colorectal neoplasm Physical activity Circulating tumor cells CYTOKINES Circulating tumor DNA
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Wearable Multifunctional Health Monitoring Systems Enabled by Ultrafast Flash-Induced 3D Porous Graphene
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作者 Se Jin Choi Chan Hyeok Kim +13 位作者 Jeong Hyeon Kim Kang Hyeon Kim Sang Yoon Park Yu Jin Ko Hosung Kang Young Bin Kim Yu Mi Woo Jae Young Seok Bongchul Kang Chang Kyu Jeong Kwi-Il Park Geon-Tae Hwang Jung Hwan Park Han Eol Lee 《Energy & Environmental Materials》 2025年第4期259-269,共11页
A wearable health monitoring system is a promising device for opening the era of the fourth industrial revolution due to increasing interest in health among modern people.Wearable health monitoring systems were demons... A wearable health monitoring system is a promising device for opening the era of the fourth industrial revolution due to increasing interest in health among modern people.Wearable health monitoring systems were demonstrated by several researchers,but still have critical issues of low performance,inefficient and complex fabrication processes.Here,we present the world’s first wearable multifunctional health monitoring system based on flash-induced porous graphene(FPG).FPG was efficiently synthesized via flash lamp,resulting in a large area in four milliseconds.Moreover,to demonstrate the sensing performance of FPG,a wearable multifunctional health monitoring system was fabricated onto a single substrate.A carbon nanotube-polydimethylsiloxane(CNT-PDMS)nanocomposite electrode was successfully formed on the uneven FPG surface using screen printing.The performance of the FPG-based wearable multifunctional health monitoring system was enhanced by the large surface area of the 3D-porous structure FPG.Finally,the FPG-based wearable multifunctional health monitoring system effectively detected motion,skin temperature,and sweat with a strain GF of 2564.38,a linear thermal response of 0.98Ω℃^(-1) under the skin temperature range,and a low ion detection limit of 10μM. 展开更多
关键词 flash-induced porous graphene nanocomposite-based electrode real-time biosignal monitoring screen printing wearable multifunctional sensor
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“嫌贫爱富”抑或“扶危济困”:农户民间放贷选择偏好研究 被引量:1
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作者 杨少雄 Calum G.Turvey 孔荣 《财贸研究》 CSSCI 北大核心 2024年第1期33-46,共14页
基于合约、借方和贷方三方面特征设计农户民间放贷离散选择实验,依据陕西、山东两省289户农户实验数据,构建效用相互依赖模型考察农户民间放贷选择偏好的内在机理,采用Mixed Logit模型探究农户选择偏好及其异质性来源。研究结果表明,农... 基于合约、借方和贷方三方面特征设计农户民间放贷离散选择实验,依据陕西、山东两省289户农户实验数据,构建效用相互依赖模型考察农户民间放贷选择偏好的内在机理,采用Mixed Logit模型探究农户选择偏好及其异质性来源。研究结果表明,农户民间放贷选择中经济理性与道义理性偏好并存。其中,经济理性体现为农户偏好向亲戚或信用水平较高的借方放贷,农户手头资金紧张时放贷意愿减弱;道义理性体现为农户偏好向经济情况比自己差、曾与自己有过互动经历且用途为生活性应急需求的借方放贷,农户拒贷有压力时放贷意愿增强。进一步研究发现,农户民间放贷选择偏好存在异质性,表现为受教育程度会强化放贷农户经济理性偏好,家庭收入会强化放贷农户道义理性偏好,风险偏好型放贷农户的道义理性偏好更弱,而山东省放贷农户的经济理性和道义理性偏好均高于陕西省。 展开更多
关键词 农户民间放贷 效用相互依赖模型 选择偏好 异质性来源 离散选择实验
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中文在线旅游评论的语言积极性偏见研究 被引量:1
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作者 刘逸 肖文杰 +2 位作者 关僖 高璇 郑子钰 《旅游科学》 CSSCI 北大核心 2024年第11期48-66,共19页
以旅游评论为代表的大数据的使用在当前旅游研究中日趋重要,但是与传统数据相比,非结构化的旅游评论数据是否能够客观地、无偏差地代表旅游者想表达的内容与情感,是广大旅游研究者尚未完全解决的难题。文章从旅游评论清洗校正问题入手,... 以旅游评论为代表的大数据的使用在当前旅游研究中日趋重要,但是与传统数据相比,非结构化的旅游评论数据是否能够客观地、无偏差地代表旅游者想表达的内容与情感,是广大旅游研究者尚未完全解决的难题。文章从旅游评论清洗校正问题入手,试图捕捉评论数据中语言积极性偏见存在的方式与程度,并测定语言积极性偏见系数。文章在控制目的地、时间、情感属性、评分等重要变量的基础上,通过非参数检验方法分组检验语言积极性偏见现象,利用分位数回归方法揭示评论评分对偏见系数的影响,采用Bootstrap方法分组估算语言积极性偏见系数。结果表明:(1)语言积极性偏见在旅游情境中普遍存在。(2)偏见系数与分位段之间不存在线性相关关系。对于低分位(正负面词汇比例小于或等于1)的评论而言,评分对偏见系数影响微弱;反之,随着分位数的提升,评分对偏见系数的影响越明显。(3)偏见系数在不同地域、不同时间存在一定的差异,但程度较弱,其值基本稳定在[2.00,2.50]区间。文章是对语言类大数据挖掘研究的一次有效推进,为数据清洗和智能处理提供了新的参考依据,同时也对语言心理学中语言情感表达偏差领域作出了积极的补充。 展开更多
关键词 文本大数据 乐观主义倾向 语言积极性偏见 旅游在线评论 情感分析
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红树林沉积物聚乙烯降解菌的筛选和降解特性 被引量:2
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作者 卫婉 聂芳红 +8 位作者 张敏 林红英 魏云丽 吕广洲 照那木拉 康丹菊 HAY Anthony GOONERATNE Ravi 陈进军 《广东海洋大学学报》 CAS CSCD 北大核心 2024年第3期143-149,共7页
【目的】探究湛江市麻章区红树林沉积物中微生物对聚乙烯(PE)塑料的降解特性,丰富红树林塑料降解菌种类。【方法】在湛江市麻章区红树林的高、中、低潮带随机选取9个样点,并采用五点采样法从红树林表层2~5 cm的沉积物中取样。将采集到... 【目的】探究湛江市麻章区红树林沉积物中微生物对聚乙烯(PE)塑料的降解特性,丰富红树林塑料降解菌种类。【方法】在湛江市麻章区红树林的高、中、低潮带随机选取9个样点,并采用五点采样法从红树林表层2~5 cm的沉积物中取样。将采集到的沉积物样本在以聚乙烯为唯一碳源的无机盐培养基中进行富集、分离、纯化,以筛选出能够降解PE的菌株,并通过显微形态分析、分子鉴定等方法确定其种属;通过测定生长曲线、失重率、以及分析官能团变化来验证菌株对PE塑料的降解性能。【结果与结论】从沉积物中共筛选出K1-1、K1-2和K1-3三株PE降解能力较强的菌,分别为威尼斯不动杆菌(Acinetobacter venetianus)、Pseudomonas juntendi和维德曼芽孢杆菌(Bacillus wiedmannii)。在120 d的培养周期中,这些菌株的生长曲线均呈抛物线形态。经三株菌作用后,PE表面生成羟基,并形成氨基和羟基化合物,羟基取代羰基,导致PE表观和内部结构明显改变。经120 d处理后,PE膜的失重率分别为6.42%、5.38%和5.73%,其中K1-1菌株处理后PE塑料的失重率相较于目前报道的红树林沉积物中最高降解效率菌株Bacillus gottheilii处理后塑料的失重率提升3.55%。威尼斯不动杆菌(A.venetianus)在PE塑料降解上具有一定潜力,这丰富了湛江红树林沉积物中PE降解菌的种类,为PE塑料的生物降解提供理论支持。 展开更多
关键词 红树林沉积物 聚乙烯塑料 降解菌 降解性能
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红景天苷及其苷元酪醇对三阴性乳腺癌细胞的抑制作用 被引量:1
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作者 王媛媛 郑必胜 +1 位作者 徐秋雄 刘瑞海 《现代食品科技》 CAS 北大核心 2024年第6期74-84,共11页
乳腺癌是当今世界发病率和死亡率极高的癌症之一,目前,毒性小、副作用低、多靶点治疗且效果好的天然产物成为乳腺癌药物开发热点。红景天中存在两种具有良好的生物活性单体红景天苷及酪醇,该研究采用ORAC法确定其抗氧化能力,以三阴性乳... 乳腺癌是当今世界发病率和死亡率极高的癌症之一,目前,毒性小、副作用低、多靶点治疗且效果好的天然产物成为乳腺癌药物开发热点。红景天中存在两种具有良好的生物活性单体红景天苷及酪醇,该研究采用ORAC法确定其抗氧化能力,以三阴性乳腺癌细胞MDA-MB-231为实验模型,考察其抗增殖效果,通过细胞划痕实验、流式细胞仪检测细胞凋亡及周期以及RT-qPCR进一步探究相关机制。结果表明,红景天苷及酪醇均能够显著抑制MDAMB-231的增殖,其EC50值分别为63.55、127.35μmol/L;细胞划痕实验表明它们能显著抑制细胞迁移,在36 h时高浓度组红景天苷和酪醇分别将细胞愈合率从72.16%降低至27.86%和32.69%;细胞周期和凋亡实验表明红景天苷和酪醇将细胞周期绝大部分阻滞在G2期并促进细胞凋亡;RT-qPCR实验发现红景天苷主要通过上调p53、p21基因,下调Bcl-2、Bcl-xL、CDK6基因发挥抗MDA-MB-231增殖效果,酪醇主要通过上调p53、p21、Bax基因发挥作用。上述结果为单体红景天苷和酪醇的生物活性研究提供理论支持,并为将来抗乳腺癌药物的开发提供理论依据。 展开更多
关键词 红景天苷 酪醇 乳腺癌 抗增殖活性
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基于可见光逆反射通信的移动增强现实定向交互 被引量:1
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作者 李景聿 陈拓潮 +7 位作者 李明哲 徐栩海 张铖 徐子晨 刘譞哲 黄罡 冯云 许辰人 《电子学报》 EI CAS CSCD 北大核心 2024年第11期3643-3656,共14页
移动增强现实应用中,用户频繁地与环境中不同的智能物体交互完成任务,其完成效率和用户体验由所采用的定向交互技术决定.然而,从交互手段上来说,现阶段定向交互依赖于Wi-Fi、BLE等无线技术,其信号全向传播的特点使其不能利用用户的空间... 移动增强现实应用中,用户频繁地与环境中不同的智能物体交互完成任务,其完成效率和用户体验由所采用的定向交互技术决定.然而,从交互手段上来说,现阶段定向交互依赖于Wi-Fi、BLE等无线技术,其信号全向传播的特点使其不能利用用户的空间环境(即位置和方向)来缩短互动时间,带来了不必要的时间成本;从交互界面上来说,现阶段基于视觉的界面存在可靠性低、扩展性低等问题,进一步限制了系统的通用性.本文介绍了RetroAR——基于可见光逆反射通信的定向交互系统.RetroAR利用了光的定向传播特性来保留用户的空间环境,并依靠逆反射通信实现用户与目标设备之间无连接的快速定向交互.系统实验表明,RetroAR最远可在4 m距离支持100°视角的交互,同时实现厘米级的六自由度(6-Degrees Of Freedom,6-DoF)三维跟踪.用户研究表明,与基于Wi-Fi的解决方案相比,RetroAR将非接触式控制的交互时间减少了2倍,并且具有更好的用户体验.RetroAR借助可见光逆反射通信来利用用户空间环境,保持交互过程中的直观性.用户可以“所指即所控”的方式与多个目标进行互动,实现类似自然交互的快速定向交互. 展开更多
关键词 移动增强现实 定向交互 所指即所控 可见光逆反射通信 聚合物分散液晶
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