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Relationship between longitudinal changes in lipid composition and ischemic stroke among hypertensive patients
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作者 Cheng-Cheng Wei Yu-Qing Huang Cheng-Hong Yu 《World Journal of Clinical Cases》 SCIE 2025年第4期18-27,共10页
BACKGROUND Dyslipidemia was strongly linked to stroke,however the relationship between dyslipidemia and its components and ischemic stroke remained unexplained.AIM To investigate the link between longitudinal changes ... BACKGROUND Dyslipidemia was strongly linked to stroke,however the relationship between dyslipidemia and its components and ischemic stroke remained unexplained.AIM To investigate the link between longitudinal changes in lipid profiles and dyslipidemia and ischemic stroke in a hypertensive population.METHODS Between 2013 and 2014,6094 hypertension individuals were included in this,and ischemic stroke cases were documented to the end of 2018.Longitudinal changes of lipid were stratified into four groups:(1)Normal was transformed into normal group;(2)Abnormal was transformed into normal group;(3)Normal was transformed into abnormal group;and(4)Abnormal was transformed into abnormal group.To examine the link between longitudinal changes in dyslipidemia along with its components and the risk of ischemic stroke,we utilized multivariate Cox proportional hazards models with hazard ratio(HR)and 95%CI.RESULTS The average age of the participants was 62.32 years±13.00 years,with 329 women making up 54.0%of the sample.Over the course of a mean follow-up of 4.8 years,143 ischemic strokes happened.When normal was transformed into normal group was used as a reference,after full adjustments,the HR for dyslipidemia and ischemic stroke among abnormal was transformed into normal group,normal was transformed into abnormal group and abnormal was transformed into abnormal Wei CC et al.Dyslipidemia changed and ischemic stroke WJCC https://www.wjgnet.com 2 February 6,2025 Volume 13 Issue 4 group were 1.089(95%CI:0.598-1.982;P=0.779),2.369(95%CI:1.424-3.941;P<0.001)and 1.448(95%CI:1.002-2.298;P=0.047)(P for trend was 0.233),respectively.CONCLUSION In individuals with hypertension,longitudinal shifts from normal to abnormal in dyslipidemia-particularly in total and low-density lipoprotein cholesterol-were significantly associated with the risk of ischemic stroke. 展开更多
关键词 Longitudinal change HYPERTENSION DYSLIPIDEMIA Lipid profile Ischemic stroke
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Oxidation Resistance of Form-stable Hightemperature Phase Change Thermal Energy Storage Materials Doped by Impregnated Graphite
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作者 LI Baorang DAI Jianhuan +2 位作者 ZHANG Wei LIU Xiangchen YANG Liu 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2025年第1期1-12,共12页
We adopted the solution impregnation route with aluminum dihydrogen phosphate solution as liquid medium for effective surface modification on graphite substrate.The mass ratio of graphite to Al(H_(2)PO_(4))_(3) change... We adopted the solution impregnation route with aluminum dihydrogen phosphate solution as liquid medium for effective surface modification on graphite substrate.The mass ratio of graphite to Al(H_(2)PO_(4))_(3) changed from 0.5:1 to 4:1,and the impregnation time changed from 1 to 7 h.The typical composite phase change thermal storage materials doped with the as-treated graphite were fabricated using form-stable technique.To investigate the oxidation and anti-oxidation behavior of the impregnated graphite at high temperatures,the samples were put into a muffle furnace for a cyclic heat test.Based on SEM,EDS,DSC techniques,analyses on the impregnated technique suggested an optimized processing conditions of a 3 h impregnation time with the ratio of graphite:Al(H_(2)PO_(4))_(3) as 1:3 for graphite impregnation treatment.Further investigations on high-temperature phase change heat storage materials doped by the treated graphite suggested excellent oxidation resistance and thermal cycling performance. 展开更多
关键词 phase change materials GRAPHITE impregnation method oxidation sintering thermal analysis
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Current understanding of adult nephrotic syndrome:Minimal change disease
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作者 Krishna Kumar 《World Journal of Nephrology》 2025年第1期149-152,共4页
The underlying molecular changes that result in minimal change disease(ne-phrotic syndrome)require an in-depth analysis.Current molecular studies have shown the involvement of zinc fingers and homeobox transcriptional... The underlying molecular changes that result in minimal change disease(ne-phrotic syndrome)require an in-depth analysis.Current molecular studies have shown the involvement of zinc fingers and homeobox transcriptional factors in its pathogenesis.The application of therapeutic drugs relies on understanding the cascade of molecular events to determine their efficacy in managing the clinical condition. 展开更多
关键词 Minimal change disease Nephrotic syndrome Hyposialylation PODOCYTES ALBUMINURIA
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Climate changes drive phytoplankton community through complementarity and selection effects in a large mesotrophic reservoir
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作者 Yue WU Qi YE +6 位作者 Siwen CHEN Lei JIANG Kaining CHEN Shuzhan MA Yiheng CHANG Jie LIU Xiaoli SHI 《Journal of Oceanology and Limnology》 2025年第1期119-133,共15页
Understanding the response of the phytoplankton community to climate change is essential for reservoir management.We analyzed a long-term data series(2009–2020)on the phytoplankton community in a large mesotrophic re... Understanding the response of the phytoplankton community to climate change is essential for reservoir management.We analyzed a long-term data series(2009–2020)on the phytoplankton community in a large mesotrophic reservoir in the wet season to investigate the impacts of temperature and precipitation increases caused by climate change on the functioning and trait composition of the phytoplankton community.Over the last twelve years,the 3-month accumulative precipitation increased from 291.03 mm to 590.91 mm,and the surface water temperature increased from 25.06℃to 26.49℃in wet season,respectively.These changes caused a higher water level,stronger thermal stratification and lower nitrogen concentration in Daxi Reservoir.The dynamic equilibrium model indicated that the increased precipitation and water temperature-related environmental changes would result in a more diverse and productive phytoplankton community.The effects of increasing water temperature and precipitation on the niche complementarity and selection effects within the phytoplankton community were analyzed using structural equation model by means of the functional divergence index and functional evenness index,respectively,elucidating the reasons for the increase in cyanobacteria in the absence of a significant increase in nutrient levels.Based on these results,it is advisable that more stringent phosphorus control standards might be conducted to reduce the risks of cyanobacteria proliferation in the context of global warming. 展开更多
关键词 global warming climate change RESERVOIR trait-based phytoplankton functional group CYANOBACTERIA
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Macular microvascular and structural changes on optical coherence tomography angiography in atypical optic neuritis
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作者 Chinmay Mahatme Madhurima Kaushik +2 位作者 Veerappan Rathinasabapathy Saravanan Karthik Kumar Virna M Shah 《World Journal of Methodology》 2025年第1期88-94,共7页
BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic im... BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases. 展开更多
关键词 Optical coherence tomography angiography Atypical optic neuritis Macular microvascular changes Neuromyelitis optica spectrum disorders Myelin oligodendrocyte glycoprotein antibody disorder
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Assessing the impact of climate change on dissolved oxygen using a flow field ecosystem model that takes into account the anaerobic and aerobic environment of bottom sediments
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作者 Jinichi Koue 《Acta Geochimica》 2025年第1期11-22,共12页
This study examines the potential impacts o climate change on Lake Biwa,Japan’s largest freshwate lake,with a focus on temperature,wind speed,and pre cipitation variations.Leveraging data from the IPCC Sixth Assessme... This study examines the potential impacts o climate change on Lake Biwa,Japan’s largest freshwate lake,with a focus on temperature,wind speed,and pre cipitation variations.Leveraging data from the IPCC Sixth Assessment Report,including CCP scenarios,projecting a significant temperature rise of 3.3–5.7℃in the case o very high GHG emission power,the research investigates how these shifts may influence dissolved oxygen levels in Lake Biwa.Through a one-dimensional model incorporat ing sediment redox reactions,various scenarios where ai temperature and wind speed are changed are simulated.I is revealed that a 5℃increase in air temperature leads to decreasing 1-2 mg/L of dissolved oxygen concentrations from the surface layer to the bottom layer,while a decrease in air temperature tends to elevate 1–3 mg/L of oxygen lev els.Moreover,doubling wind speed enhances surface laye oxygen but diminishes it in deeper layers due to increased mixing.Seasonal variations in wind effects are noted with significant surface layer oxygen increases from 0.4to 0.8 mg/L during summer to autumn,increases from 0.4 to 0.8 mg/L in autumn to winter due to intensified vertica mixing.This phenomenon impacts the lake’s oxygen cycle year-round.In contrast,precipitation changes show limited impact on oxygen levels,suggesting minor influence com pared to other meteorological factors.The study suggests the necessity of comprehensive three-dimensional models that account for lake-specific and geographical factors fo accurate predictions of future water conditions.A holistic approach integrating nutrient levels,water temperature,and river inflow is deemed essential for sustainable management of Lake Biwa’s water resources,particularly in addressing precipitation variations. 展开更多
关键词 Climate change Dissolved oxygen Sediment redox reaction Stratifi cation Water quality
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Study on discharge characteristics of low-temperature sub-atmospheric pressure under steep change rate voltage
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作者 Bo ZHU Ximu HAN +2 位作者 He SU Xiangjie MA Guoyan WU 《Plasma Science and Technology》 2025年第1期52-61,共10页
Aiming at the gas discharge problem in electric aircraft,this work studies the gas discharge characteristics at low-temperature sub-atmospheric pressure.A gas discharge shooting platform was built,and the discharge pr... Aiming at the gas discharge problem in electric aircraft,this work studies the gas discharge characteristics at low-temperature sub-atmospheric pressure.A gas discharge shooting platform was built,and the discharge process was photographed by intensified charge-coupled device(ICCD).A two-dimensional axisymmetric model of needle-plate electrode gas discharge was established,and three sets of Helmholtz equations were used to solve the photoionization.The results show that under the same voltage,the electric field intensity in the discharge process increases first,then decreases and finally increases again.The discharge speed increases with the increase of altitude,and the electron density in the streamer decreases with the increase of altitude.The development speed of the streamer in the middle stage is higher than that in the early stage,and the speed increases more obviously with the increase of altitude.The development speed of the streamer in the later stage is lower than that in the middle stage,but with the increase of altitude,the development speed of the streamer in the later stage is higher than that in the middle stage. 展开更多
关键词 electric aircraft gas discharge steep change rate voltage electric field intensity electron density
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Reconstructing forest and grassland cover changes in China over the past millennium
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作者 Fanneng HE Fan YANG Yafei WANG 《Science China Earth Sciences》 2025年第1期94-110,共17页
Historical forest and grassland cover changes not only are critical indicators for quantifying ecological and environmental change processes but also serve as fundamental data for long-term climate change simulations ... Historical forest and grassland cover changes not only are critical indicators for quantifying ecological and environmental change processes but also serve as fundamental data for long-term climate change simulations and terrestrial ecosystem carbon emission assessments.However,because of limitations in historical data,quantitative estimations and spatially gridded reconstructions of these changes remain challenging,necessitating further methodological exploration.This study focused on China's present-day land area over the past millennium,objectively capturing the characteristics and drivers of forest and grassland cover changes.On 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 reconstruct historical forest area changes based on the functional relationship between the forest area and population size dynamics.Subsequently,a gridded forest allocation model was established on the basis of deforestation tendencies.For the grassland cover,we implemented regionspecific methods,such as the cropland area deduction method and the habitat constraint method,to quantitatively reconstruct historical changes.Consequently,we obtained provincial forest and grassland area changes over the past millennium and mapped 10-km-resolution gridded data of forest and grassland cover.The results indicated the following.(1)The methods developed using population data as a proxy objectively reproduced the spatiotemporal evolution of forest and grassland cover in China over the past millennium.These feasible methods offer a novel pathway for the quantitative reconstruction of historical forest and grassland cover changes.(2)The data indicated that China's forest area generally decreased over the past millennium,characterized by a“decrease-then-increase”pattern.The forest area experienced three distinct phases:a slow decline(AD 1000–1650),a rapid decline(AD 1650–1960),and a gradual recovery(AD 1960–2000).The area decreased from 298 million hectares(Mha)in AD 1000 to 89 Mha in AD 1960 before increasing to 153 Mha in AD 2000.Spatially,deforestation began in the middlelower reaches of the Yellow River and gradually expanded to the middle-lower reaches of the Yangtze River,the southern coastal areas of China,southwest China,and northeast China,with the forest cover declining by 27%,40%,58%,55%,and 35%in these regions,respectively.(3)China's grassland area has shown a continuous decline over the past millennium with three phases:stable fluctuation(AD 1000–1600),slow decline(AD 1600–1900),and rapid decline(AD 1900–2000).The grassland area decreased from 305 Mha in AD 1000 to 277 Mha in AD 2000.Notably,zonal grassland areas in Northeast China,Inner Mongolia,Gan-Ning,Qinghai,Xinjiang,and Xizang decreased by 28 Mha over the millennium,whereas nonzonal secondary grassland areas in the hilly and mountainous areas of eastern and southern China increased by 0.3 Mha. 展开更多
关键词 Land use and land cover change FOREST GRASSLAND Quantitative reconstruction Gridded reconstruction China historical period
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Impact of Climate Change on Crop-cropland Coupling Relationship:A Case Study of the Loess Plateau in China
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作者 LI Shunke LIU Yansui +1 位作者 SHAO Yajing WANG Xiaochen 《Chinese Geographical Science》 2025年第1期92-110,共19页
Climate change brings new challenges to the sustainable development of agriculture in the new era.Accurately grasping the patterns of climate change impacts on agricultural systems is crucial for ensuring agricultural... Climate change brings new challenges to the sustainable development of agriculture in the new era.Accurately grasping the patterns of climate change impacts on agricultural systems is crucial for ensuring agricultural sustainability and food security.Taking the Loess Plateau(LP),China as an example,this study used a coupling coordination degree model and spatial autocorrelation analysis to portray the spatial and temporal features of crop-cropland coupling relationship from 2000 to 2020 and explored the impact law of climate change through geographically and temporally weighted regression(GTWR).The results were as follows:1)the crop-cropland coupling coordination degree of the LP showed a gradual upward trend from 2000 to 2020,forming a spatial pattern with lower values in the central region and higher values in the surrounding areas.2)There was a positive correlation in the spatial distribution of cropcropland coupling coordination degree in the LP from 2000 to 2020,and the high value-low value(H-L)and low value-low value(L-L)agglomerations continued to expand eastward,while the spatial and temporal evolution of the high value-high value(H-H)and low value-high value(L-H)agglomerations was not obvious.3)The impacts of climatic elements on crop-cropland coupling coordination degree in the LP showed strong heterogeneity in time scales.The inhibitory impacts of summer days(SU)and frost days(FD)accounted for a higher proportion,while the annual average temperature(TEM)had both promoting and inhibiting impacts.The impacts proportion and intensity of extreme heavy precipitation day(R25),continuous drought days(CDD),and annual precipitation(PRE)all experienced significant changes.4)In space,the impacts of SU and FD on the crop-cropland coupling coordination degree varied with latitude and altitude.The adaptability of the LP to R25 gradually strengthened,and the extensions of CDD and increase of PRE led to the increasing inhibition beyond the eastern region of LP,and TEM showed a promoting impact in the Fenwei Plain.As an important grainproducing area in China,the LP should actively deal with the impacts of climate change on the crop-cropland coupling relationship,vigorously safeguard food security,and promote sustainable agricultural development. 展开更多
关键词 climate change crop-cropland coupling relationship geographically and temporally weighted regression(GTWR) extreme weather events Loess Plateau China
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木质素-稻草改良土的力学特性与修正Duncan-Chang模型
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作者 覃诗卉 江学良 +3 位作者 杨慧 陈晓洁 沈维焕 尹红乖 《湖南城市学院学报(自然科学版)》 2025年第1期8-15,共8页
木质素具有胶结土体的作用,稻草纤维也具备提高土体抗剪强度的能力,而采用木质素和稻草共同改良红黏土的研究相对较少。本文通过固结不排水三轴试验,获得了木质素-稻草改良土在不同围压和不同木质素掺量下的应力-应变曲线,并据此研究该... 木质素具有胶结土体的作用,稻草纤维也具备提高土体抗剪强度的能力,而采用木质素和稻草共同改良红黏土的研究相对较少。本文通过固结不排水三轴试验,获得了木质素-稻草改良土在不同围压和不同木质素掺量下的应力-应变曲线,并据此研究该改良土的力学特性;同时通过建立修正Duncan-Chang模型,来分析木质素掺量对模型参数的影响。研究结果表明:改良土主应力差随木质素掺量的增加先增大后减小,当木质素的掺量为0.7%时,其到达最大值;改良土初始变形模量Ei、极限偏应力(σ1-σ3)ult、黏聚力c、内摩擦角φ及参数K均随木质素掺量的增加先增大后减小,参数n随木质素掺量的增加而增大,而破坏比Rf受木质素掺量的影响较小。 展开更多
关键词 木质素 纤维加筋土 红黏土 三轴试验 应力-应变关系 修正Duncan-chang模型
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Non-alcoholic fatty liver disease: What has changed in the treatment since the beginning? 被引量:11
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作者 Bülent Baran Filiz Akyüz 《World Journal of Gastroenterology》 SCIE CAS 2014年第39期14219-14229,共11页
Non-alcoholic fatty liver disease(NAFLD) is an umbrella term to describe the entire spectrum of this common liver disease. In patients with NAFLD, especially those with non-alcoholic steatohepatitis(NASH), most often ... Non-alcoholic fatty liver disease(NAFLD) is an umbrella term to describe the entire spectrum of this common liver disease. In patients with NAFLD, especially those with non-alcoholic steatohepatitis(NASH), most often have one or more components of the metabolic syndrome, but this is not universal. Although most patients with NAFLD share many clinical features, only a subset of patients develops significant liver inflammation and progressive fibrosis. On the other hand, not all patients with NASH exhibit insulin resistance. NASH can be seen in patients who are lean and have no identifiable risk factors. Many clinical studies have tried numerous drugs and alternative medicine, however, investigators have failed to identify a safe and effective therapy for patients with NASH. As summarized, the heterogeneity of pathogenic pathways in individual patients with NASH may warrant the development of an individualized treatment according to the underlying pathogenic pathway. The differentiation of pathogenetic targets may require the development of diagnostic and prognostic biomarkers, and the identification of genetic susceptibilities. At present, evidence-based medicine provides only a few options including life-style modifications targeting weight loss, pioglitazone and vitamin E in non-diabetic patients with biopsy-proven NASH. 展开更多
关键词 Non-alcoholic steatohepatitis PATHOGENESIS INFLAMMATION FIBROSIS Life-style changes Pharmacologic treatment
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Simulation of the mixing process in a straight tube with sudden changed cross-section 被引量:3
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作者 Yangcheng LU Shan Zhu +1 位作者 Kai Wang Guangsheng Luo 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第6期711-718,共8页
In this work, we revised the expression of mixing intensity to describe the mixing output through a cross section in a flow system by considering heterogeneity of flow field, and carefully investigated the mixing proc... In this work, we revised the expression of mixing intensity to describe the mixing output through a cross section in a flow system by considering heterogeneity of flow field, and carefully investigated the mixing process along a straight tube with expanding/contracting cross section by simulation method. The simulation results show that a sudden expansion of cross section has remarkable mixing intensification effect within a limited period(on the sub-second scale) or tube-length(on the millimeter scale), corresponding to the generation of considerable local vortices determined by both the flow capacity and the ratio of cross section change; a sudden contraction of cross section has instantaneous but weak mixing intensification effect; through introducing a local expansion structure with proper length, as the combination of sudden expansion and sudden contraction, their mixing intensification effects could be superposed. Besides, the rationality and importance are experimentally verified to explore the time profile of mixing intensity and carry out the vortex analysis by simulation for enhancing the selectivity of a complicated reaction system. These progresses may lead to more meaningful quantitative description of mixing process in a flow microreactor for some specific chemical processes. 展开更多
关键词 MixingIntensificationSimulationSudden change in cross-sectionVortex
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Striving for the development of biology——The celebration of Biomagnelism formally changed into Progress in Modem Biomedicine 被引量:2
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作者 Editorial Department of Progress in Modern Biomedicine 《现代生物医学进展》 CAS 2006年第6期F0002-F0002,共1页
关键词 Striving for the development of biology The celebration of Biomagnelism formally changed into Progress in Modem Biomedicine
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Recent advances in graphene-based phase change composites for thermal energy storage and management 被引量:2
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作者 Qiang Zhu Pin Jin Ong +4 位作者 Si Hui Angela Goh Reuben J.Yeo Suxi Wang Zhiyuan Liu Xian Jun Loh 《Nano Materials Science》 EI CAS CSCD 2024年第2期115-138,共24页
Energy storage and conservation are receiving increased attention due to rising global energy demands.Therefore,the development of energy storage materials is crucial.Thermal energy storage(TES)systems based on phase ... Energy storage and conservation are receiving increased attention due to rising global energy demands.Therefore,the development of energy storage materials is crucial.Thermal energy storage(TES)systems based on phase change materials(PCMs)have increased in prominence over the past two decades,not only because of their outstanding heat storage capacities but also their superior thermal energy regulation capability.However,issues such as leakage and low thermal conductivity limit their applicability in a variety of settings.Carbon-based materials such as graphene and its derivatives can be utilized to surmount these obstacles.This study examines the recent advancements in graphene-based phase change composites(PCCs),where graphene-based nanostructures such as graphene,graphene oxide(GO),functionalized graphene/GO,and graphene aerogel(GA)are incorporated into PCMs to substantially enhance their shape stability and thermal conductivity that could be translated to better storage capacity,durability,and temperature response,thus boosting their attractiveness for TES systems.In addition,the applications of these graphene-based PCCs in various TES disciplines,such as energy conservation in buildings,solar utilization,and battery thermal management,are discussed and summarized. 展开更多
关键词 Phase change material NANOCOMPOSITES Solar energy Sustainable energy Thermo-regulation
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基于统计损伤修正的冻结砂—黏混合土改进Duncan-Chang模型
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作者 滕振超 李正巍 +7 位作者 刘佳琳 周亚东 李波 刘彦峰 池林林 张圣童 刘博 计静 《东北石油大学学报》 CAS 北大核心 2024年第2期116-124,I0008,共10页
为描述冻结砂—黏混合土的偏应力—应变关系,进行不同含砂量冻结砂—黏混合土的冻土三轴压缩试验。基于改进的Duncan-Chang模型(D-C模型),引入统计损伤理论,拟合三轴压缩试验结果,分别建立以Mises强度准则和应变发展为微元强度变量的统... 为描述冻结砂—黏混合土的偏应力—应变关系,进行不同含砂量冻结砂—黏混合土的冻土三轴压缩试验。基于改进的Duncan-Chang模型(D-C模型),引入统计损伤理论,拟合三轴压缩试验结果,分别建立以Mises强度准则和应变发展为微元强度变量的统计损伤修正模型,对比计算结果与试验数据。结果表明:冻结砂—黏混合土偏应力峰值随含砂量的增加而增加,偏应力—应变曲线由应变硬化型逐渐过渡到应变软化型的临界含砂量为50%。当含砂量介于20%~60%时,基于统计损伤理论的修正改进D-C模型能有效拟合应变硬化型曲线和具有轻微应变软化现象的偏应力—应变曲线。当含砂量为90%时,基于应变发展的统计损伤修正模型的偏应力峰值与试验结果相差3%,具有较强适用性。该结果为不同微元强度变量的统计损伤修正模型提供参考。 展开更多
关键词 冻结砂—黏混合土 三轴压缩试验 改进Duncan-chang模型 统计损伤理论 应变软化模型
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Response of vegetation variation to climate change and human activities in the Shiyang River Basin of China during 2001-2022 被引量:1
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作者 SUN Chao BAI Xuelian +2 位作者 WANG Xinping ZHAO Wenzhi WEI Lemin 《Journal of Arid Land》 SCIE CSCD 2024年第8期1044-1061,共18页
Understanding the response of vegetation variation to climate change and human activities is critical for addressing future conflicts between humans and the environment,and maintaining ecosystem stability.Here,we aime... Understanding the response of vegetation variation to climate change and human activities is critical for addressing future conflicts between humans and the environment,and maintaining ecosystem stability.Here,we aimed to identify the determining factors of vegetation variation and explore the sensitivity of vegetation to temperature(SVT)and the sensitivity of vegetation to precipitation(SVP)in the Shiyang River Basin(SYRB)of China during 2001-2022.The climate data from climatic research unit(CRU),vegetation index data from Moderate Resolution Imaging Spectroradiometer(MODIS),and land use data from Landsat images were used to analyze the spatial-temporal changes in vegetation indices,climate,and land use in the SYRB and its sub-basins(i.e.,upstream,midstream,and downstream basins)during 2001-2022.Linear regression analysis and correlation analysis were used to explore the SVT and SVP,revealing the driving factors of vegetation variation.Significant increasing trends(P<0.05)were detected for the enhanced vegetation index(EVI)and normalized difference vegetation index(NDVI)in the SYRB during 2001-2022,with most regions(84%)experiencing significant variation in vegetation,and land use change was determined as the dominant factor of vegetation variation.Non-significant decreasing trends were detected in the SVT and SVP of the SYRB during 2001-2022.There were spatial differences in vegetation variation,SVT,and SVP.Although NDVI and EVI exhibited increasing trends in the upstream,midstream,and downstream basins,the change slope in the downstream basin was lower than those in the upstream and midstream basins,the SVT in the upstream basin was higher than those in the midstream and downstream basins,and the SVP in the downstream basin was lower than those in the upstream and midstream basins.Temperature and precipitation changes controlled vegetation variation in the upstream and midstream basins while human activities(land use change)dominated vegetation variation in the downstream basin.We concluded that there is a spatial heterogeneity in the response of vegetation variation to climate change and human activities across different sub-basins of the SYRB.These findings can enhance our understanding of the relationship among vegetation variation,climate change,and human activities,and provide a reference for addressing future conflicts between humans and the environment in the arid inland river basins. 展开更多
关键词 vegetation variation climate change land use change normalized difference vegetation index(NDVI) enhanced vegetation index(EVI) Shiyang River Basin
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Timing theory integrated nursing combined behavior change integrated theory of nursing on primiparous influence 被引量:2
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作者 Yan-Xia He Yang Lv +2 位作者 Ting-Ting Lan Fang Deng Yuan-Yuan Zhang 《World Journal of Clinical Cases》 SCIE 2024年第2期293-301,共9页
BACKGROUND The comprehension and utilization of timing theory and behavior change can offer a more extensive and individualized provision of support and treatment alternatives for primipara.This has the potential to e... BACKGROUND The comprehension and utilization of timing theory and behavior change can offer a more extensive and individualized provision of support and treatment alternatives for primipara.This has the potential to enhance the psychological well-being and overall quality of life for primipara,while also furnishing healthcare providers with efficacious interventions to tackle the psychological and physiological obstacles encountered during the stages of pregnancy and postpartum.AIM To explore the effect of timing theory combined with behavior change on selfefficacy,negative emotions and quality of life in patients with primipara.METHODS A total of 80 primipara cases were selected and admitted to our hospital between August 2020 and May 2022.These cases were divided into two groups,namely the observation group and the control group,with 40 cases in each group.The nursing interventions differed between the two groups,with the control group receiving routine nursing and the observation group receiving integrated nursing based on the timing theory and behavior change.The study aimed to compare the pre-and post-nursing scores of Chinese Perceived Stress Scale(CPSS),Edinburgh Postpartum Depression Scale(EPDS),Self-rating Anxiety Scale(SAS),breast milk knowledge,self-efficacy,and SF-36 quality of life in both groups.RESULTS After nursing,the CPSS,EPDS,and SAS scores of the two groups was significantly lower than that before nursing,and the CPSS,EPDS,and SAS scores of the observation group was significantly lower than that of the control group(P=0.002,P=0.011,and P=0.001 respectively).After nursing,the breastfeeding knowledge mastery,selfefficacy,and SF-36 quality of life scores was significantly higher than that before nursing,and the breastfeeding knowledge mastery(P=0.013),self-efficacy(P=0.008),and SF-36 quality of life(P=0.011)scores of the observation group was significantly higher than that of the control group.CONCLUSION The integration of timing theory and behavior change integrated theory has been found to be an effective approach in alleviating negative mood and stress experienced by primipara individuals,while also enhancing their selfefficacy and overall quality of life.This study focuses on the key concepts of timing theory,behavior change,primipara individuals,negative mood,and quality of life. 展开更多
关键词 Timing theory Behavior change PRIMIPARA Bad mood Quality of life
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Precipitation and anthropogenic activities regulate the changes of NDVI in Zhegucuo Valley on the southern Tibetan Plateau 被引量:1
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作者 ZHAO Wanglin WANG Hengying +1 位作者 ZHANG Huifang ZHANG Lin 《Journal of Mountain Science》 SCIE CSCD 2024年第2期607-618,共12页
Whether climate change or anthropogenic activities play a more pivotal role in regulating vegetation growth on the Tibetan Plateau is still controversial.A better understanding on grassland changes at a fine scale may... Whether climate change or anthropogenic activities play a more pivotal role in regulating vegetation growth on the Tibetan Plateau is still controversial.A better understanding on grassland changes at a fine scale may provide important guidance for local government policy and grassland management.Using two of the most reliable satellite NDVI products(MODIS NDVI and SPOT NDVI),we evaluated the dynamic of grasslands in the Zhegucuo valley on the southern Tibetan Plateau from 2000 to 2020,and analyzed its driving factors and relative influences of climate change and anthropogenic activities.Here,the key indicators of climate change were assumed to be precipitation and temperature.The main results were:(1)the grassland NDVI in Zhegucuo valley did not reflect a significant temporal change during the last 21 years.The variation of precipitation during the early growing season(GSP)resembled that of NDVI,and the GSP was positively correlated with NDVI.At the pixel level,the partial correlation analysis showed that 37.79%of the pixels depicted a positive relationship between GSP and NDVI,while 11.32%of the pixels showed a negative relationship between temperature during the early growing season(GST)and NDVI.(2)In view of the spatial distribution,the areas mainly controlled by GSP were generally distributed in the southern part,while those affected by GST stood in the eastern part,mainly around the Zhegucuo lake where most population in Cuomei County settled down.(3)Decreasing NDVI trends were mainly occurred in alpine steppe at lower elevations rather than alpine meadow at higher elevations.(4)The residual trend(RESTREND)analysis further indicated that the anthropogenic activities played a more pivotal role in regulating the annual changes of NDVI rather than climate factors in this area.Future studies should pay more attention on climate extremes rather than the simple temporal trends.Also,the influence of human activities on alpine grassland needs to be accessed and fully considered in future sustainable management. 展开更多
关键词 Anthropogenic activities Climate change PRECIPITATION FENCING Vegetation degradation
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Global Change in Agricultural Flash Drought over the 21st Century 被引量:1
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作者 Emily BLACK 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第2期209-220,I0002-I0019,共30页
Agricultural flash droughts are high-impact phenomena, characterized by rapid soil moisture dry down. The ensuing dry conditions can persist for weeks to months, with detrimental effects on natural ecosystems and crop... Agricultural flash droughts are high-impact phenomena, characterized by rapid soil moisture dry down. The ensuing dry conditions can persist for weeks to months, with detrimental effects on natural ecosystems and crop cultivation. Increases in the frequency of these rare events in a future warmer climate would have significant societal impact. This study uses an ensemble of 10 Coupled Model Intercomparison Project(CMIP) models to investigate the projected change in agricultural flash drought during the 21st century. Comparison across geographical regions and climatic zones indicates that individual events are preceded by anomalously low relative humidity and precipitation, with long-term trends governed by changes in temperature, relative humidity, and soil moisture. As a result of these processes, the frequency of both upperlevel and root-zone flash drought is projected to more than double in the mid-and high latitudes over the 21st century, with hot spots developing in the temperate regions of Europe, and humid regions of South America, Europe, and southern Africa. 展开更多
关键词 flash drought climate change soil moisture agricultural drought CMIP
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Shikimic acid accelerates phase change and flowering in Chinese jujube 被引量:1
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作者 Xianwei Meng Zhiguo Liu +11 位作者 Li Dai Weiqiang Zhao Jiurui Wang Lili Wang Yuanpei Cui Ying Li Yinshan Cui Yao Zhang Luyao Wang Fengjiao Yu Jin Zhao Mengjun Liu 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第2期413-424,共12页
The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely un... The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely unknown. Shikimic acid (ShA) pathway is a main metabolic pathway closely related to the synthesis of hormones and many important secondary metabolites participating in plant phase change. So,whether ShA regulates phase change in plants is worth clarifying. Here, the distinct morphological characteristics and the underlying mechanisms of phase change in jujube (Ziziphus jujuba Mill.), an important fruit tree native to China with nutritious fruit and outstanding tolerance abiotic stresses, were clarified. A combined transcriptome and metabolome analysis found that ShA is positively involved in jujube(Yuhong’×Xing 16’) phase change. The genes in the upstream of ShA synthesis pathway (ZjDAHPS, ZjDHQS and ZjSDH), the contents of ShA and the downstream secondary metabolites like phenols were significantly upregulated in the phase change period. Further, the treatment of spraying exogenous ShA verified that ShA at a very low concentration (60 mg·L^(-1)) can substantially speed up the phase change and flowering of jujube and other tested plants including Arabidopsis, tomato and wheat. The exogenous ShA (60 mg·L^(-1)) treatment in jujube seedlings could increase the accumulation of endogenous ShA, enhance leaf photosynthesis and the synthesis of phenols especially flavonoids and phenolic acids, and promote the expression of genes (ZjCOs, ZjNFYs and ZjPHYs) involved in flowering pathway. Basing on above results, we put forward a propose for the underlying mechanism of ShA regulating phase change, and a hypothesis that ShA could be considered a phytohormone-like substance because it is endogenous, ubiquitous, movable and highly efficient at very low concentrations. This study highlights the critical role of ShA in plant phase change and its phytohormone-like properties. 展开更多
关键词 Ziziphus jujuba Mill. Phase change FLOWERING Shikimic acid TRANSCRIPTOME METABOLOME
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