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基于日尺度SPEI的黄土高原干旱时空变化特征及影响因素分析
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作者 杨广 史海静 +3 位作者 姜艳敏 吴友福 王椰 李冀 《水土保持研究》 北大核心 2025年第2期244-254,共11页
[目的]探究黄土高原地区气象干旱的时空变化特征及其影响因素,以期为该地区的干旱监测、旱作农业粮食生产、水资源管理及生态恢复建设提供科学支撑。[方法]基于黄土高原地区119个站点1957—2019年逐日气象资料,使用FAO Penman-Monteith... [目的]探究黄土高原地区气象干旱的时空变化特征及其影响因素,以期为该地区的干旱监测、旱作农业粮食生产、水资源管理及生态恢复建设提供科学支撑。[方法]基于黄土高原地区119个站点1957—2019年逐日气象资料,使用FAO Penman-Monteith公式计算了日尺度潜在蒸散发及标准化降水蒸散指数(SPEI),并采用Theil-Sen Median斜率估计和Mann-Kendall趋势分析,探讨了干旱天数、干旱事件发生次数和强度的分布特征及变化趋势。同时,使用皮尔逊相关系数分析气象因子与干旱指标的关系,并结合土地利用类型转移矩阵探讨了人类活动对气象干旱的影响。[结果](1)日尺度SPEI在识别干旱天数、干旱事件发生次数和强度方面比月尺度SPEI更为精确;(2) 1957—2019年黄土高原西北地区干旱事件发生次数增加,大部分区域干旱强度呈现不断增加的趋势,不同类型干旱的天数有所降低;(3)黄土高原东南部和西北部地区存在明显的变干趋势,而北部和南部地区则呈现出湿润化趋势;(4)气象因子与干旱指标之间存在中等相关关系,土地利用/地表覆盖对黄土高原地区的气象干旱产生了一定程度的影响。[结论]黄土高原地区的气象干旱受气候因素和人类活动的双重影响,其时空变化特征复杂。研究结果为该地区的干旱监测与管理提供了重要的科学依据。 展开更多
关键词 黄土高原 日尺度spei 气象干旱 Theil-Sen Median斜率估计
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Diagnostic implications of neutrophil-to-lymphocyte ratio,platelet-tolymphocyte ratio,and systemic immune-inflammatory index for gastric carcinoma 被引量:1
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作者 Huang-Min Wu Xiao-Xuan Ying +1 位作者 Li-Li Lv Jian-Wen Hu 《World Journal of Gastrointestinal Surgery》 2025年第1期139-146,共8页
BACKGROUND The diagnosis of gastric carcinoma(GC)is essential for improving clinical outcomes.However,the biomarkers currently used for GC screening are not ideal.AIM To explore the diagnostic implications of the neut... BACKGROUND The diagnosis of gastric carcinoma(GC)is essential for improving clinical outcomes.However,the biomarkers currently used for GC screening are not ideal.AIM To explore the diagnostic implications of the neutrophil-to-lymphocyte ratio(NLR),platelet-to-lymphocyte ratio(PLR),and systemic immune-inflammatory index(SII)for GC.METHODS The baseline data of 133 patients with GC and 134 patients with precancerous gastric conditions admitted between January 2022 and December 2023 were retrospectively analyzed.The information on peripheral blood platelet,neutrophil,and lymphocyte counts in each patient was collected,and the NLR,PLR,and SII levels of both groups were calculated.Additionally,multivariate logistic regression analysis was conducted,and the diagnostic implications of NLR,PLR,and SII in differentiating patients with precancerous gastric conditions,compared with those with GC,were analyzed through receiver operating characteristic(ROC)curves.RESULTS The data indicated that NLR,PLR,and SII had abnormally increased levels in the patients with GC.Gender and body mass index were risk factors for the occurrence of GC.ROC data revealed that the areas under the curve of three patients with precancerous gastric conditions,who were differentiated from those with GC,were 0.824,0.787,and 0.842,respectively.CONCLUSION NLR,PLR,and SII are all abnormally expressed in GC and have diagnostic implications,especially when used as joint indicators,in distinguishing patients with precancerous gastric conditions from those with GC. 展开更多
关键词 Gastric carcinoma Neutrophil-to-lymphocyte ratio Platelet-to-lymphocyte ratio Precancerous gastric conditions Systemic immune-inflammatory index
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Predicting Standardized Precipitation Evapotranspiration Index for Fada N’Gourma by 2050 Using CMPI-6 Outputs under SSPs Scenarios
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作者 Tog-Noma Patricia Emma Bontogho Andrew Ireson +1 位作者 Dominic Boateng-Gyambiby Abdullahi Dini 《Journal of Environmental Science and Engineering(A)》 CAS 2025年第1期31-42,共12页
Extreme weather events,such as floods and droughts,are expected to rise significantly worldwide as a result of climate change.Investigating future drought patterns is therefore a key approach for elaborating anticipat... Extreme weather events,such as floods and droughts,are expected to rise significantly worldwide as a result of climate change.Investigating future drought patterns is therefore a key approach for elaborating anticipatory water resources management responses to climate change.In this paper,future meteorological drought conditions are investigated based on the SPEI(Standardised Precipitation Evapotranspiration Index).This study makes use of observed and projected data.The simulated data were retrieved from the CMIP6(Coupled Model Intercomparison Project Phase 6)over the period 2025-2050,and the Delta change method was adopted to remove the bias in the dataset.Then SPEI at various scales has been estimated under four future scenarios(SSP1-2.6,SSP2-4.5,SSP3-7.0 and SSP5-8.5).The trend analysis of the projected SPEI was performed at p<0.05 using the MMK(Modified Mann-Kendall)test in order to detect the statistically significant trend of the drought against the null hypothesis of no trend.Results show large variability in the magnitude of drought in the past and future.Based on SPEI at 24 months accumulation,the result shows that under SSP1-2.6,the basin will experience a wet period during the first decade(SPEI=0.60),the second decade will be dry(SPEI24=-0.43).The remaining years will be also dry(SPEI=-0.34).Under SSP2-4.5,SSP3-7.0 and SSP5-8.5 scenarios,the district will experience a wet period during the first two decades with SPEI ranging from 0.38 to 0.59.This wet period will be followed by a dry period under these scenarios ranging from-0.14 to-0.06.Overall,under SSPs scenarios,two main periods characterized by a rainfall recovery spanning from followed by a moderately prolonged drought are identified within the study area.The findings of this study may provide valuable information for developing proactive measures to reduce water insecurity in Fada N’Gourma through effective drought mitigation. 展开更多
关键词 Climate change drought index CMPI-6 Fada N’Gourma SSP-scenarios.
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Construction of Vocational Education Quality Evaluation Index System from the Perspective of Digital Transformation Based on the Analytic Hierarchy Process of Higher Vocational Colleges in Hainan Province,China
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作者 Limei Fu 《Journal of Contemporary Educational Research》 2025年第1期282-289,共8页
In the context of the digital transformation of vocational education,a quality evaluation index system has been constructed.Based on a questionnaire survey conducted among higher vocational colleges and enterprises in... In the context of the digital transformation of vocational education,a quality evaluation index system has been constructed.Based on a questionnaire survey conducted among higher vocational colleges and enterprises in Hainan Province,it has been found that the quality of vocational education generally depends on the talent training program and professional construction at the macro level.At the meso level,the teacher level and teaching environment are critical,while at the micro level,the evaluation of talent training quality cannot be underestimated.Strategies for quality improvement in vocational education are proposed from the perspectives of talent training programs,major construction,teacher development,teaching environment,and talent training quality,all under the lens of digital transformation. 展开更多
关键词 Digital transformation Vocational education Evaluation index system
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一类虚拟纽结的Affine Index多项式
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作者 郭兴博 《应用数学进展》 2025年第1期462-468,共7页
纽结理论是拓扑学的一个重要分支,虚拟纽结理论是经典纽结理论的推广,对它的研究是通过一种图解理论来展开的。虚拟纽结多项式是一类以多项式表达的虚拟纽结不变量,例如Arrow多项式和Wriggle多项式。Affine index多项式是以虚拟纽结图... 纽结理论是拓扑学的一个重要分支,虚拟纽结理论是经典纽结理论的推广,对它的研究是通过一种图解理论来展开的。虚拟纽结多项式是一类以多项式表达的虚拟纽结不变量,例如Arrow多项式和Wriggle多项式。Affine index多项式是以虚拟纽结图的整数标记定义的单变量多项式。本文主要计算一类特殊虚拟纽结的Affine index多项式。按照Cheng着色的规则,对虚拟纽结图的每一段弧进行整数标记,计算每个经典交叉点的指标值,进而得到这类特殊虚拟纽结的Affine index多项式的表达式。Knot theory is an important branch of topology. Virtual knot theory is a generalization of classical knot theory, and its research is carried out through a graphic theory. The virtual knot polynomial refers to a class of virtual knot invariant expressed by polynomials, such as the Arrow polynomial and the Wriggle polynomial. The affine index polynomial is a univariate polynomial defined by the integer label of a virtual knot graph. In this paper, we mainly calculate affine index polynomials for a special class of virtual knots. According to the rules of Cheng coloring, we will integer label each arc of the virtual knot graph and calculate the index value of each classical crossings, and then get the expression of the affine index polynomial of this special virtual knot. 展开更多
关键词 虚拟纽结 Affine index多项式 Cheng着色 纽结不变量
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Association between body mass index and lumbar spine volumetric bone mineral density in diabetic and non-diabetic patients
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作者 Fang Lv Xiao-Ling Cai +4 位作者 Xiu-Ying Zhang Xiang-Hai Zhou Xue-Yao Han Yu-Feng Li Li-Nong Ji 《World Journal of Diabetes》 2025年第2期103-113,共11页
BACKGROUND The association between body mass index(BMI)and bone mineral density(BMD)has shown inconsistent results,varying by sex and skeletal site.Despite normal or elevated bone mass,individuals with type 2 diabetes... BACKGROUND The association between body mass index(BMI)and bone mineral density(BMD)has shown inconsistent results,varying by sex and skeletal site.Despite normal or elevated bone mass,individuals with type 2 diabetes have an increased risk of hip and vertebral fractures.AIM To assess lumbar spine trabecular volumetric BMD(vBMD)across different BMI categories in individuals with and without diabetes.METHODS This cross-sectional study included 966 men over 50 years old and 1001 postmenopausal women from the Pinggu Metabolic Disease Study.The vBMD of lumbar vertebrae 2 through 4 was measured using quantitative computed tomography.Total adipose tissue,subcutaneous adipose tissue(SAT),visceral adipose tissue(VAT),and lumbar skeletal muscle area were also quantified.RESULTS In men with obesity(P=0.038)and overweight(P=0.032),vBMD was significantly higher in the diabetes group compared to non-diabetic men.After adjusting for age and sex,no significant saturation effect between BMI and BMD was found in participants with diabetes or in women without diabetes.However,a BMI threshold of 22.33 kg/m²indicated a saturation point for vBMD in nondiabetic men.Independent predictors of vBMD in men included age(r=-0.387,P<0.001),BMI(r=0.130,P=0.004),and VAT(r=-0.145,P=0.001).For women,significant predictors were age(r=-0.594,P<0.001),BMI(r=0.157,P=0.004),VAT(r=-0.112,P=0.001),and SAT(r=-0.068,P=0.035).CONCLUSION The relationship between BMI and trabecular vBMD differs in individuals with and without diabetes.Overweight and obese men with diabetes exhibit higher vBMD. 展开更多
关键词 Obesity and overweight Body mass index DIABETES Lumbar spine volumetric bone mineral density Quantitative computed tomography
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Cross-sectional study of the association between triglyceride glucose-body mass index and obstructive sleep apnea risk
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作者 Li Gong Ming Su +9 位作者 Jing-Han Xu Zhen-Fei Peng Lin Du Ze-Yao Chen Yu-Zhou Liu Lu-Cia Chan Yin-Luan Huang Yu-Tian Chen Feng-Yi Huang Chun-Li Piao 《World Journal of Diabetes》 2025年第3期65-75,共11页
BACKGROUND The triglyceride glucose-body mass index(TyG-BMI)is a novel indicator of insulin resistance(IR).Obstructive sleep apnea(OSA)is a prevalent disorder characterized by recurrent complete or partial collapse of... BACKGROUND The triglyceride glucose-body mass index(TyG-BMI)is a novel indicator of insulin resistance(IR).Obstructive sleep apnea(OSA)is a prevalent disorder characterized by recurrent complete or partial collapse of the pharyngeal airway during sleep;however,the relationship between these two conditions remains unexplored.We hypothesized that a higher TyG-BMI is associated with the occurrence of OSA.AIM To assess the association between TyG-BMI and OSA in adults in the United States.METHODS A cross-sectional study was conducted utilizing data from the National Health and Nutrition Examination Surveys spanning from 2005-2008 to 2015-2018.TyGBMI was calculated as Ln[triglyceride(mg/dL)×fasting blood glucose(mg/dL)/2]×BMI.Restricted cubic splines were used to analyze the risk of TyG-BMI and OSA occurrence.To identify potential nonlinear relationships,we combined Cox proportional hazard regression with smooth curve fitting.We also conducted sensitivity and subgroup analyses to verify the robustness of our findings.RESULTS We included 16794 participants in the final analysis.Multivariate regression analysis showed that participants with a higher TyG-BMI had a higher OSA incidence.After adjusting for all covariates,TyG-BMI was positively correlated with the prevalence of OSA(odds ratio:1.28;95%confidence interval:1.17,1.40;P<0.001);no significant nonlinear relationship was observed.Subgroup analysis showed no strong correlation between TyG-BMI and OSA in patients with diabetes.The correlation between TyG-BMI and OSA was influenced by age,sex,smoking status,marital status,hypertensive stratification,and obesity;these subgroups played a moderating role between TyGBMI and OSA.Even after adjusting for all covariates,there was a positive association between TYG-BMI and OSA prevalence.CONCLUSION A higher TyG-BMI index is linked to higher chances of developing OSA.As TyG-BMI is an indicator of IR,managing IR may help reduce the risk of OSA. 展开更多
关键词 Obstructive sleep apnea Triglyceride glucose-body mass index Insulin resistance CROSS-SECTIONAL National Health and Nutrition Examination Surveys
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A cross-sectional study of the association between dietary inflammatory index and glaucoma prevalence in a US population
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作者 Wen-Li Chen Li-Xia Zhang 《International Journal of Ophthalmology(English edition)》 2025年第1期139-145,共7页
AIM:To assess the relationship between dietary inflammatory index(DII)and prevalence of glaucoma among individuals aged 40y and above in the United States.METHODS:Participants were drawn from 2 cycles of the National ... AIM:To assess the relationship between dietary inflammatory index(DII)and prevalence of glaucoma among individuals aged 40y and above in the United States.METHODS:Participants were drawn from 2 cycles of the National Health and Nutrition Examination Survey(NHANES,2005-2008)for a cross-sectional study.DII was calculated from 24-hour dietary recall questionnaire conducted by experienced researchers and data analyzed in R according to the NHANES user guide,“Stratified Multi-stage Probability Sampling”.The relationship between DII and glaucoma was evaluated by multi-factor logistic regression analysis and the existence of a non-linear association examined by restricted cubic spline(RCS)analysis.RESULTS:A total of 5359 subjects were included and the cross-sectional analysis weighted to represent the US population of 109 million.DII was elevated in glaucoma patients(P<0.001)and smoking and alcohol use contributed to significant differences(P<0.001).DII correlated negatively with Healthy Eating Index(HEI)-2015(Spearman rank correlation coefficient,r=-0.49).RCS analysis showed a linear relationship between DII and glaucoma risk(P of non-linear relationship=0.575).CONCLUSION:An increased DII is strongly associated with high risk of glaucoma and diet-induced inflammation should be controlled to delay glaucoma progression. 展开更多
关键词 glaucoma risk factors dietar y inflammatory index National Health and Nutrition Examination Survey restricted cubic spline regression cross-sectional study
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基于SPEI的洮河流域气象干旱时空特征分析 被引量:2
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作者 瞿德业 杨明月 +5 位作者 刘婷婷 杨山泉 谌越 夏搏 柴文博 丁春伟 《水利水电科技进展》 CSCD 北大核心 2024年第5期32-40,共9页
基于洮河流域1976—2020年逐月的气温和降水量资料,计算了季尺度和年尺度的标准化降水蒸散指数(SPEI),采用时间序列平稳性检验法和干旱频率法定量分析了季尺度和年尺度不同等级气象干旱频率的变化规律及空间分布特征,采用云模型分析了... 基于洮河流域1976—2020年逐月的气温和降水量资料,计算了季尺度和年尺度的标准化降水蒸散指数(SPEI),采用时间序列平稳性检验法和干旱频率法定量分析了季尺度和年尺度不同等级气象干旱频率的变化规律及空间分布特征,采用云模型分析了年尺度气象干旱时空分布的随机性与稳定性。结果表明:在季尺度上,四季的干旱频率都在30%左右,干旱主要发生在春冬两季;在年尺度上,流域以轻旱、中旱为主,轻旱、中旱发生频率高,重旱、特旱发生频率偏低,总体偏干旱;在空间分布上,干旱主要发生在流域的中下游区域;1976—2020年流域干旱化程度有所减弱,干旱化趋势稳定,干旱化程度波动较小。 展开更多
关键词 气象干旱 时空特征 spei 云模型 洮河流域
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基于SPEI的黑龙江省干旱时空分布特征分析 被引量:1
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作者 施巧 姜宁 +1 位作者 孟凡香 田肖冉 《水电能源科学》 北大核心 2024年第3期29-32,共4页
为分析黑龙江省干旱时空分布特征,利用黑龙江省27个站点1961~2020年的气象数据,采用Penman-Monteith公式计算不同时间尺度的标准化降水蒸散指数(SPEI),从时间尺度和空间尺度分析黑龙江省干旱的分布特征。结果表明,黑龙江省近60年来干旱... 为分析黑龙江省干旱时空分布特征,利用黑龙江省27个站点1961~2020年的气象数据,采用Penman-Monteith公式计算不同时间尺度的标准化降水蒸散指数(SPEI),从时间尺度和空间尺度分析黑龙江省干旱的分布特征。结果表明,黑龙江省近60年来干旱趋势在逐渐减弱,慢慢呈现湿润化趋势;春、夏、秋季呈不显著湿润化趋势(P>0.05),冬季呈显著湿润化趋势(P<0.05);在空间上其北部、西北部和东北部为干旱频发区,且干旱程度上多以轻旱和中旱为主。黑龙江省整体上干旱趋势减弱,干旱时空分布具有较明显的季节性和区域性。 展开更多
关键词 spei指数 干旱 时空分布特征 黑龙江省
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基于SPEI指数的松花江下游流域干旱时空特征分布
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作者 刘涛 司振江 刘岩 《水利科学与寒区工程》 2024年第11期35-39,共5页
研究松花江下游流域1967—2019年气象干旱时空特征。利用松花江下游流域9个站点的气象资料,采用Penman-Monteith公式计算月、季、年尺度下区域的标准化降水蒸散指数(SPEI),运用Menn-Kendall检验和Pettitt突变检验,分析该地区的干旱时空... 研究松花江下游流域1967—2019年气象干旱时空特征。利用松花江下游流域9个站点的气象资料,采用Penman-Monteith公式计算月、季、年尺度下区域的标准化降水蒸散指数(SPEI),运用Menn-Kendall检验和Pettitt突变检验,分析该地区的干旱时空分布特征。结果表明:松花江下游流域干旱趋势在逐渐减弱,多以轻旱和中旱为主;松花江下游流域年干旱情况的突变点是1980年;不同季节尺度上,不显著湿润化趋势(P<0.05)季节为春季、夏季、冬季,显著湿润化趋势(P>0.05)季节为秋季。松花江下游流域整体上干旱趋势减弱,干旱时空分布有较明显的季节性和区域性。 展开更多
关键词 spei指数 Menn-Kendall检验 Pettitt突变检验 松花江流域
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1981─2020年河北省基于SPEI的干旱变化特征分析
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作者 魏丽欣 赵春雷 +2 位作者 张良玉 高万泉 王欢 《江西农业学报》 CAS 2024年第1期95-101,共7页
基于1981─2020年河北省138个气象站点的逐月降水和气温数据,计算了不同时间尺度的标准化降水蒸散指数(SPEI),并利用Sen趋势分析、Mann-Kendall检验及反距离权重插值等方法,分析了河北省近40年干旱的时空变化特征。结果表明:1981─2020... 基于1981─2020年河北省138个气象站点的逐月降水和气温数据,计算了不同时间尺度的标准化降水蒸散指数(SPEI),并利用Sen趋势分析、Mann-Kendall检验及反距离权重插值等方法,分析了河北省近40年干旱的时空变化特征。结果表明:1981─2020年河北省月、季、年尺度的SPEI值均呈下降趋势,且随着时间尺度的加大,发生干旱的频率下降,持续时间延长。春季、夏季和年际的SPEI值均呈下降趋势,秋季和冬季的SPEI值均呈上升趋势。2016─2020、2011─2020年春季和冬季均处于变湿状态,夏季和秋季均处于变干状态。2011─2020年河北省大部分地区呈干旱状态。不同年代季尺度和年尺度的干旱频率整体上呈增加趋势。河北省发生的轻、中度干旱事件多于重度以上干旱事件。20世纪90年代、21世纪10年代SPEI值减少区域的占比大。20世纪80年代、21世纪00年代SPEI值增加区域的占比大。 展开更多
关键词 河北省 spei指数 干旱 变化特征
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基于GRACE重力卫星与SPEI的云南干旱监测 被引量:1
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作者 游智文 李肖肖 +1 位作者 阳勇 鲁梦格 《节水灌溉》 北大核心 2024年第3期34-41,49,共9页
针对云南省干旱多发、旱灾严重的特点,选取1981年1月-2020年6月长时间序列的历史时期典型水文干旱年及干旱事件,探索GRACE卫星反演数据在监测云南地区干旱方面的适用性,旨在提出解决无资料或少资料地区干旱监测困难的新方法。研究基于GR... 针对云南省干旱多发、旱灾严重的特点,选取1981年1月-2020年6月长时间序列的历史时期典型水文干旱年及干旱事件,探索GRACE卫星反演数据在监测云南地区干旱方面的适用性,旨在提出解决无资料或少资料地区干旱监测困难的新方法。研究基于GRACE重力卫星数据反演得到云南省滇中、滇东北、滇东南、滇西南、滇西北5个分区月均储水量变化量,计算各分区的旱涝指标-相对储水量指数,利用相对储水量指数对云南省各分区干旱情况进行分析,并从月时间尺度上对比了相对储水量指数和标准降水蒸散指数SPEI3的干旱分析结论。研究结果表明:基于GRACE重力卫星数据反演构建的相对储水量指数在典型水文干旱年内的监测结果与实际干旱情况基本一致,其在滇中地区的适用性最佳,对于春季干旱的监测精度优于其他季节,反演数据能够一定程度上反映云南省不同地区、不同季节干旱程度;利用SPEI3对云南全省以及不同分区的旱情进行监测,结果与统计年鉴记载干旱事件较为吻合,其在滇东南地区的监测精度优于其他分区,在夏、冬两季精度优于春季;GRACE和SPEI3都较好地捕捉到了历史时期的典型干旱年及干旱事件,在选取的24场典型干旱事件中各分区的最高吻合率均达到了15/24;总体上两种指数在各分区漏报率均维持在较低水平,最高不超过1/3,其中SPEI3相较于GRACE更不易出现漏报的情况,其最低漏报率仅为1/8,两种指数在全省及各分区的旱情监测方面均表现出较好的适用性。 展开更多
关键词 云南省 GRACE卫星数据反演 干旱指数 相对储水量指数 spei 干旱监测 监测精度
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基于SPEI的陕西苹果产区近60a干旱变化特征
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作者 张勇 黄俊芳 +3 位作者 刘璐 张维敏 屈振江 梁轶 《中国农学通报》 2024年第23期105-117,共13页
研究旨在明确气候变暖背景下陕西苹果产区的干旱变化特征,为陕西苹果产区适应气候变化,科学指导陕西苹果防旱减损提供参考。利用陕西省苹果产区近60 a的气象站月降水、气温资料,计算陕西苹果各产区年、生长季、各生育期的标准化降水蒸... 研究旨在明确气候变暖背景下陕西苹果产区的干旱变化特征,为陕西苹果产区适应气候变化,科学指导陕西苹果防旱减损提供参考。利用陕西省苹果产区近60 a的气象站月降水、气温资料,计算陕西苹果各产区年、生长季、各生育期的标准化降水蒸散指数SPEI,对其进行趋势、突变和周期变化分析。研究结果表明近60 a陕西苹果产区年际明显趋于干旱,生长季总体趋于干旱,突变点多集中在1970s和1990s,1990s后干旱趋势较为明显,其中渭北东部产区干旱趋势尤为显著、干旱风险持续增加;萌芽—幼果期干旱趋势十分明显,干旱风险持续增加,突变点多集中在1970s后期至1980s初期和1990s初期,1990s初期后干旱趋势较为明显,产区中渭北西部、渭北东部、关中的干旱趋势显著;着色—成熟期、越冬休眠期总体趋于干旱,突变点多集中在1970s,1970s中后期以来呈干旱趋势,各产区均存在干旱趋势但变化趋势不显著;果实膨大期则以波动变化为主,未有显著的变化趋势。基于SPEI的干旱分析结合了降雨和蒸散发、考虑了更长时间尺度、适用于不同气候区域,更能客观反映气候变暖背景下陕西苹果产区干旱情况。气候变化造成的降水偏少、气温升高是陕西苹果产区趋于干旱的主要影响因素。 展开更多
关键词 陕西苹果 spei 分生育期 趋势 突变 周期
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基于SPEI的北疆1961—2020年气象干旱变化特征
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作者 卫炎豪 古丽娜孜 +3 位作者 巴特尔·巴克 帕丽扎提·玉素甫 祖力克艳·麻那甫 帕提古力·麦麦提 《湖北农业科学》 2024年第5期37-44,214,共9页
基于北疆26个主要气象站点1961—2020年逐日气象数据,选取标准化降水蒸散指数(SPEI)为气象干旱指标,采用Mann-Kendall突变检验、小波分析等方法对北疆年及春、夏两季SPEI和不同等级气象干旱影响范围变化特征进行了探究。结果表明,北疆... 基于北疆26个主要气象站点1961—2020年逐日气象数据,选取标准化降水蒸散指数(SPEI)为气象干旱指标,采用Mann-Kendall突变检验、小波分析等方法对北疆年及春、夏两季SPEI和不同等级气象干旱影响范围变化特征进行了探究。结果表明,北疆实际轻旱情况更适合以-1.0<SPEI≤0识别;与年尺度的湿润化趋势相反,北疆春、夏两季均呈不同程度的干旱化趋势,且夏季极端气象干旱(重旱、特旱)事件影响范围有显著扩大趋势;1961—2020年不同尺度SPEI有1~4年的主变化周期;北疆整体气候于20世纪80年代转变后在1993—2010年呈显著湿润化趋势,春、夏季气候分别于2014年及1997年出现了由湿转干的趋势信号;研究区夏季的干旱情况于1988年开始逐渐缓解,但在2008年再次突变后干旱情况又开始逐步加剧。 展开更多
关键词 标准化降水蒸散指数(spei) 气象干旱 小波分析 Mann-Kendall突变检验 北疆
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基于SPEI指数的辽宁省玉米干旱特征分析
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作者 王艺霖 王蕊 +3 位作者 单凤君 张筱渲 赵诣 孙颖 《辽宁工业大学学报(自然科学版)》 2024年第4期273-280,共8页
基于1961—2020年辽宁省24个国家级气象台站逐日观测数据,根据SPEI的计算、Mann-Kendall法、小波分析法,采用灰色关联度分析方法,对辽宁省玉米不同生长阶段标准降水蒸散指数(SPEI)进行了定量评价,并进行比较全面的分析。结果表明,从玉... 基于1961—2020年辽宁省24个国家级气象台站逐日观测数据,根据SPEI的计算、Mann-Kendall法、小波分析法,采用灰色关联度分析方法,对辽宁省玉米不同生长阶段标准降水蒸散指数(SPEI)进行了定量评价,并进行比较全面的分析。结果表明,从玉米全生育期来看,近60 a降水量总体变化趋势并不显著,与SPEI呈显著正相关;辽宁省玉米生长期平均气温与SPEI呈负相关;玉米全生育期SPEI在时间上均呈上升趋势;从整体来看,在干旱站次比方面辽宁省的玉米生产并没有全域性干旱现象。 展开更多
关键词 spei 干旱站次比 辽宁省 玉米 气象干旱
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Standardized Baseflow Drought Index Comparison to SPEI in High Baseflow Streams
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作者 Katherine A. Clancy 《Journal of Water Resource and Protection》 2023年第11期557-580,共24页
Increased use of streamflow, most importantly minimum flow/baseflow data should be incorporated into drought indices, especially in regions where streams have a high baseflow component. Standard departure for streamfl... Increased use of streamflow, most importantly minimum flow/baseflow data should be incorporated into drought indices, especially in regions where streams have a high baseflow component. Standard departure for streamflow (SDSF) and standard departure for baseflow (SDBF) were compared to the standardized precipitation and evapotranspiration index (SPEI) drought index values for 17 baseflow-dominated watersheds in the northern, central, and southern regions of Wisconsin. For each watershed, comparisons of SDSF, SDBF, and SPEI time series (for 1, 3, and 12-month time scales) were evaluated using correlation, run lengths of negative and positive values, sign congruence, and Mann-Kendall trend test. In general, SDBF performed better than SDSF for longer time scales. Trends of wetness appear to be distinguished earlier in SDBF compared to SDSF and SPEI-1, SPEI-3, and SPEI-12. The results of this study are consistent with regional statewide climate studies on precipitation and changes in precipitation intensity. This study highlights how standardized baseflow data are robust and compare to SPEI 12-month time scales. 展开更多
关键词 spei BASEFLOW Drought Indices Streamflow
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Association between the cumulative triglyceride-glucose index and the recurrence of atrial fibrillation after radiofrequency catheter ablation 被引量:1
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作者 Qing YAN Jia-Qi LIANG +5 位作者 Yi-De YUAN Yuan LI Jia-Li FAN Wen-Huan WU Pan XU Jia-Hong XUE 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2024年第2期200-210,共11页
BACKGROUND Triglyceride-glucose(TyG)index values are a new surrogate marker for insulin resistance.This study aimed to explore the relationship between cumulative TyG index values and atrial fibrillation(AF)recurrence... BACKGROUND Triglyceride-glucose(TyG)index values are a new surrogate marker for insulin resistance.This study aimed to explore the relationship between cumulative TyG index values and atrial fibrillation(AF)recurrence after radiofrequency catheter ablation(RFCA).METHODS A total of 576 patients with AF who underwent RFCA at the Second Affiliated Hospital of Xi'an Jiaotong University were included in this study.The participants were grouped based on cumulative TyG index values tertiles within 3 months after ablation.Cox regression and restricted cubic spline analyses were used to determine the relationship between cumulative TyG index values and AF recurrence.The predictive value of all risk factors was assessed by receiver operating curve analysis.RESULTS There were 375 patients completed the study(age:63.23±10.73 years,64.27%male).The risk of AF recurrence increased with increasing cumulative TyG index values tertiles.After adjusting for potential confounders,patients in the medium cumulative TyG index group[hazard ratio(HR)=4.949,95%CI:1.778–13.778,P=0.002]and the high cumulative TyG index group(HR=8.716,95%CI:3.371–22.536,P<0.001)had a higher risk of AF recurrence than those in the low cumulative TyG index group.The restricted cubic spline regression model also showed an increased risk of AF recurrence with increasing cumulative TyG index values.When considering cumulative TyG index values,left atrial diameter,and lactate dehydrogenase levels as a comprehensive factor,the model could effectively predict AF recurrence after RFCA[area under the curve(AUC)=0.847,95%CI:0.797–0.897,P<0.001].CONCLUSIONS Cumulative TyG index values were a risk factor for AF recurrence after RFCA.Monitoring longitudinal TyG index values may assist with optimized for risk stratification and outcome prediction for AF recurrence. 展开更多
关键词 ATRIAL FIBRILLATION index
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Early peripheral perfusion index predicts 28-day outcome in patients with septic shock 被引量:1
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作者 Cheng Chi Hao Gong +2 位作者 Kai Yang Peng Peng Xiaoxia Zhang 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2024年第5期372-378,共7页
BACKGROUND:To investigate the prognostic value of the peripheral perfusion index(PPI)in patients with septic shock.METHODS:This prospective cohort study,conducted at the emergency intensive care unit of Peking Univers... BACKGROUND:To investigate the prognostic value of the peripheral perfusion index(PPI)in patients with septic shock.METHODS:This prospective cohort study,conducted at the emergency intensive care unit of Peking University People's Hospital,recruited 200 patients with septic shock between January 2023 and August 2023.These patients were divided into survival(n=84)and death(n=116)groups based on 28-day outcomes.Clinical evaluations included laboratory tests and clinical scores,with lactate and PPI values assessed upon admission to the emergency room and at 6 h and 12 h after admission.Risk factors associated with mortality were analyzed using univariate and multivariate Cox regression analyses.Receiver operator characteristic(ROC)curve was used to assess predictive performance.Mortality rates were compared,and Kaplan-Meier survival plots were created.RESULTS:Compared to the survival group,patients in the death group were older and had more severe liver damage and coagulation dysfunction,necessitating higher norepinephrine doses and increased fl uid replacement.Higher lactate levels and lower PPI levels at 0 h,6 h,and 12 h were observed in the death group.Multivariate Cox regression identifi ed prolonged prothrombin time(PT),decreased 6-h PPI and 12-h PPI as independent risk factors for death.The area under the curves for 6-h PPI and 12-h PPI were 0.802(95%CI 0.742-0.863,P<0.001)and 0.945(95%CI 0.915-0.974,P<0.001),respectively,which were superior to Glasgow Coma Scale(GCS),Sequential Organ Failure Assessment(SOFA)scores(0.864 and 0.928).Cumulative mortality in the low PPI groups at 6 h and 12 h was signifi cantly higher than in the high PPI groups(6-h PPI:77.52%vs.22.54%;12-h PPI:92.04%vs.13.79%,P<0.001).CONCLUSION:PPI may have value in predicting 28-day mortality in patients with septic shock. 展开更多
关键词 Peripheral perfusion index Septic shock PROGNOSIS Predictive value
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Actuality and underlying mechanisms of systemic immuneinflammation index and geriatric nutritional risk index prognostic value in hepatocellular carcinoma 被引量:1
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作者 Konstantin Y Tchilikidi 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第2期260-265,共6页
This editorial contains comments on the article“Correlation between preoperative systemic immune inflammation index,nutritional risk index,and prognosis of radical resection of liver cancer”in a recent issue of the ... This editorial contains comments on the article“Correlation between preoperative systemic immune inflammation index,nutritional risk index,and prognosis of radical resection of liver cancer”in a recent issue of the World Journal of Gastrointestinal Surgery.It pointed out the actuality and importance of the article and focused primarily on the underlying mechanisms making the systemic immuneinflammation index(SII)and geriatric nutritional risk index(GNRI)prediction features valuable.There are few publications on both SII and GNRI together in hepatocellular carcinoma(HCC)and patient prognosis after radical surgery.Neutrophils release cytokines,chemokines,and enzymes,degrade extracellular matrix,reduce cell adhesion,and create conditions for tumor cell invasion.Neutrophils promote the adhesion of tumor cells to endothelial cells,through physical anchoring.That results in the migration of tumor cells.Pro-angiogenic factors from platelets enhance tumor angiogenesis to meet tumor cell supply needs.Platelets can form a protective film on the surface of tumor cells.This allows avoiding blood flow damage as well as immune system attack.It also induces the epithelial-mesenchymal transformation of tumor cells that is critical for invasiveness.High SII is also associated with macro-and microvascular invasion and increased numbers of circulating tumor cells.A high GNRI was associated with significantly better progression-free and overall survival.HCC patients are a very special population that requires increased attention.SII and GNRI have significant survival prediction value in both palliative treatment and radical surgery settings.The underlying mechanisms of their possible predictive properties lie in the field of essential cancer features.Those features provide tumor nutrition,growth,and distribution throughout the body,such as vascular invasion.On the other hand,they are tied to the possibility of patients to resist tumor progression and development of complications in both postoperative and cancer-related settings.The article is of considerable interest.It would be helpful to continue the study follow-up to 2 years and longer.External validation of the data is needed. 展开更多
关键词 Systemic immune-inflammation index Geriatric nutritional risk index Radical surgery Transarterial chemoembolization Hepatocellular carcinoma Prognosis
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