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Sex differences in the association between the muscle quality index and the incidence of depression: A cross-sectional study
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作者 Gui-Ping Huang Li-Ping Mai +2 位作者 Zhi-Jie Zheng Xi-Pei Wang Guo-Dong He 《World Journal of Psychiatry》 SCIE 2024年第9期1335-1345,共11页
BACKGROUND Depression presents significant challenges to mental health care.Although phy-sical activity is highly beneficial to mental and physical health,relatively few stu-dies have conducted on the relationship bet... BACKGROUND Depression presents significant challenges to mental health care.Although phy-sical activity is highly beneficial to mental and physical health,relatively few stu-dies have conducted on the relationship between them.AIM To investigate the association between muscle quality index(MQI)and incidence of depression.METHODS The data used in this cross-sectional study were obtained from the 2011-2014 National Health and Nutritional Examination Survey,which included informa-tion on MQI,depression,and confounding factors.Multivariable logistic regre-ssion models were employed,while taking into account the complex multi-stage sampling design.A restricted cubic spline model was utilized to investigate the non-linear relationship between the MQI and depression.Additionally,subgroup analyses were performed to identify influential factors.RESULTS The prevalence of depression in this population was 8.44%.With the adjusted model,the MQI was associated with depression in females(odds ratio=0.68,95%confidence interval:0.49-0.95)but not in males(odds ratio=1.08,95%confidence interval:0.77-1.52).Restricted cubic spline adjustment of all covariates showed a significant negative non-linear relationship between depression and the MQI in females.The observed trend indicated an 80%decrease in the risk of depression for each unit increase in MQI,until a value of 2.2.Subsequently,when the MQI exceeded 2.2,the prevalence of depression increased by 20%for every unit increase in the MQI.Subgroup analyses further confirmed that the MQI was negatively associated with de-pression.CONCLUSION The MQI was inversely correlated with depression in females but not males,suggesting that females with a higher MQI might decrease the risk of depression. 展开更多
关键词 Sex differences Muscle quality index DEPRESSION National Health and Nutrition Examination Survey Population-based study
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Assessment of vegetation cover changes and the contributing factors in the Al-Ahsa Oasis using Normalized Difference Vegetation Index(NDVI)
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作者 Walid CHOUARI 《Regional Sustainability》 2024年第1期42-53,共12页
The abandonment of date palm grove of the former Al-Ahsa Oasis in the eastern region of Saudi Arabia has resulted in the conversion of delicate agricultural area into urban area.The current state of the oasis is influ... The abandonment of date palm grove of the former Al-Ahsa Oasis in the eastern region of Saudi Arabia has resulted in the conversion of delicate agricultural area into urban area.The current state of the oasis is influenced by both expansion and degradation factors.Therefore,it is important to study the spatiotemporal variation of vegetation cover for the sustainable management of oasis resources.This study used Landsat satellite images in 1987,2002,and 2021 to monitor the spatiotemporal variation of vegetation cover in the Al-Ahsa Oasis,applied multi-temporal Normalized Difference Vegetation Index(NDVI)data spanning from 1987 to 2021 to assess environmental and spatiotemporal variations that have occurred in the Al-Ahsa Oasis,and investigated the factors influencing these variation.This study reveals that there is a significant improvement in the ecological environment of the oasis during 1987–2021,with increase of NDVI values being higher than 0.10.In 2021,the highest NDVI value is generally above 0.70,while the lowest value remains largely unchanged.However,there is a remarkable increase in NDVI values between 0.20 and 0.30.The area of low NDVI values(0.00–0.20)has remained almost stable,but the region with high NDVI values(above 0.70)expands during 1987–2021.Furthermore,this study finds that in 1987–2002,the increase of vegetation cover is most notable in the northern region of the study area,whereas from 2002 to 2021,the increase of vegetation cover is mainly concentrated in the northern and southern regions of the study area.From 1987 to 2021,NDVI values exhibit the most pronounced variation,with a significant increase in the“green”zone(characterized by NDVI values exceeding 0.40),indicating a substantial enhancement in the ecological environment of the oasis.The NDVI classification is validated through 50 ground validation points in the study area,demonstrating a mean accuracy of 92.00%in the detection of vegetation cover.In general,both the user’s and producer’s accuracies of NDVI classification are extremely high in 1987,2002,and 2021.Finally,this study suggests that environmental authorities should strengthen their overall forestry project arrangements to combat sand encroachment and enhance the ecological environment of the Al-Ahsa Oasis. 展开更多
关键词 Normalized difference Vegetation index(NDVI) Vegetation cover Ecological environment Land use and land cover(LULC) Urban expansion Al-Ahsa Oasis
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Interannual Variability of the Normalized Difference Vegetation Index on the Tibetan Plateau and Its Relationship with Climate Change 被引量:24
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作者 周定文 范广洲 +3 位作者 黄荣辉 方之芳 刘雅勤 李洪权 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2007年第3期474-484,共11页
The Qinghai-Xizang Plateau, or Tibetan Plateau, is a sensitive region for climate change, where the manifestation of global warming is particularly noticeable. The wide climate variability in this region significantly... The Qinghai-Xizang Plateau, or Tibetan Plateau, is a sensitive region for climate change, where the manifestation of global warming is particularly noticeable. The wide climate variability in this region significantly affects the local land ecosystem and could consequently lead to notable vegetation changes. In this paper, the interannual variations of the plateau vegetation are investigated using a 21-year normalized difference vegetation index (NDVI) dataset to quantify the consequences of climate warming for the regional ecosystem and its interactions. The results show that vegetation coverage is best in the eastern and southern plateau regions and deteriorates toward the west and north. On the whole, vegetation activity demonstrates a gradual enhancement in an oscillatory manner during 1982-2002. The temporal variation also exhibits striking regional differences: an increasing trend is most apparent in the west, south, north and southeast, whereas a decreasing trend is present along the southern plateau boundary and in the central-east region. Covariance analysis between the NDVI and surface temperature/precipitation suggests that vegetation change is closely related to climate change. However, the controlling physical processes vary geographically. In the west and east, vegetation variability is found to be driven predominantly by temperature, with the impact of precipitation being of secondary importance. In the central plateau, however, temperature and precipitation factors are equally important in modulating the interannual vegetation variability. 展开更多
关键词 Tibetan Plateau normalized difference vegetation index (NDVI) ECOSYSTEM climate change interannual variability
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A second modified normalized difference water index(SMNDWI) in the case of extracting the shoreline 被引量:9
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作者 LI Ming ZHENG Xiao-shen 《Marine Science Bulletin》 CAS 2016年第2期15-27,共13页
Due to the fast development of industrialization and urbanization, shorelineextraction is necessary for the sustainable development and environment protection inmany countries. This study focused on the accurate metho... Due to the fast development of industrialization and urbanization, shorelineextraction is necessary for the sustainable development and environment protection inmany countries. This study focused on the accurate methods of extracting theinstantaneous waterline —shoreline obtained as the same instant as the satellite imageis acquired. Based on NDWI (Normalized Difference Water Index) and MNDWI(Modified Normalized Difference Water Index), the study changed the bandcombination and proposed a second modified normalized water index (SMNDWI) toextract the waterline. And, this new index is applied to three types of coast to evaluatethe performance of this method with traditional ones. Results show that SNDWI isbetter than NDWI and suitable for applying to the waterline extraction. 展开更多
关键词 SHORELINE normalized difference water index LANDSAT
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Correction to:Commentary review on the use of normalized difference vegetation index(NDVI)in the era of popular remote sensing 被引量:2
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作者 Sha Huang Lina Tang +2 位作者 Joseph PHupy Yang Wang Guofan Shao 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第6期2719-2719,共1页
The article“A commentary review on the use of normalized difference vegetation index(NDVI)in the era of popular remote sensing”,written by Sha Huang·Lina Tang·Joseph P.Hupy·Yang Wang and Guofan Shao,w... The article“A commentary review on the use of normalized difference vegetation index(NDVI)in the era of popular remote sensing”,written by Sha Huang·Lina Tang·Joseph P.Hupy·Yang Wang and Guofan Shao,was originally published electronically on the publisher’s internet portal on 31st May 2020 without open access.With the author(s)’decision to opt for Open Choice the copyright of the article changed on 25th July 2020 to©The Author(s)2020 and the article is forthwith distributed under a Creative Commons Attribution 4.0 International License(https://creativecommons.org/licenses/by/4.0/),which permits use,sharing,adaptation,distribution and reproduction in any medium or format,as long as you give appropriate credit to the original author(s)and the source,provide a link to the Creative Commons licence,and indicate if changes were made. 展开更多
关键词 difference index LICENSE
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Simple method for extracting the seasonal signals of photochemical reflectance index and normalized difference vegetation index measured using a spectral reflectance sensor 被引量:2
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作者 Jae-Hyun RYU Dohyeok OH Jaeil CHO 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2021年第7期1969-1986,共18页
A spectral reflectance sensor(SRS)fixed on the near-surface ground was developed to support the continuous monitoring of vegetation indices such as the normalized difference vegetation index(NDVI)and photochemical ref... A spectral reflectance sensor(SRS)fixed on the near-surface ground was developed to support the continuous monitoring of vegetation indices such as the normalized difference vegetation index(NDVI)and photochemical reflectance index(PRI).NDVI is useful for indicating crop growth/phenology,whereas PRI was developed for observing physiological conditions.Thus,the seasonal change patterns of NDVI and PRI are two valuable pieces of information in a crop-monitoring system.However,capturing the seasonal patterns is considered challenging because the vegetation index values estimated by the reflection from vegetation are often governed by meteorological conditions,such as solar irradiance and precipitation.Further,unlike growth/phenology,the physiological condition has diurnal changes as well as seasonal characteristics.This study proposed a novel filtering method for extracting the seasonal signals of SRS-based NDVI and PRI in paddy rice,barley,and garlic.First,the measurement accuracy of SRSs was compared with handheld spectrometers,and the R^(2)values between the two devices were 0.96 and 0.81 for NDVI and PRI,respectively.Second,the experimental study of threshold criteria with respect to meteorological variables(i.e.,insolation,cloudiness,sunshine duration,and precipitation)was conducted,and sunshine duration was the most useful one for excluding distorted values of the vegetation indices.After data processing based on sunshine duration,the R^(2)values between the measured vegetation indices and the extracted seasonal signals of vegetation indices increased by approximately 0.002–0.004(NDVI)and 0.065–0.298(PRI)on the three crops,and the seasonal signals of vegetation indices became noticeably improved.This method will contribute to an agricultural monitoring system by identifying the seasonal changes in crop growth and physiological conditions. 展开更多
关键词 photochemical reflectance index normalized difference vegetation index VEGETATION remote sensing spectral reflectance sensor
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Drought trend analysis in a semi-arid area of Iraq based on Normalized Difference Vegetation Index, Normalized Difference Water Index and Standardized Precipitation Index 被引量:1
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作者 Ayad M F AL-QURAISHI Heman A GAZNAYEE Mattia CRESPI 《Journal of Arid Land》 SCIE CSCD 2021年第4期413-430,共18页
Drought was a severe recurring phenomenon in Iraq over the past two decades due to climate change despite the fact that Iraq has been one of the most water-rich countries in the Middle East in the past.The Iraqi Kurdi... Drought was a severe recurring phenomenon in Iraq over the past two decades due to climate change despite the fact that Iraq has been one of the most water-rich countries in the Middle East in the past.The Iraqi Kurdistan Region(IKR)is located in the north of Iraq,which has also suffered from extreme drought.In this study,the drought severity status in Sulaimaniyah Province,one of four provinces of the IKR,was investigated for the years from 1998 to 2017.Thus,Landsat time series dataset,including 40 images,were downloaded and used in this study.The Normalized Difference Vegetation Index(NDVI)and the Normalized Difference Water Index(NDWI)were utilized as spectral-based drought indices and the Standardized Precipitation Index(SPI)was employed as a meteorological-based drought index,to assess the drought severity and analyse the changes of vegetative cover and water bodies.The study area experienced precipitation deficiency and severe drought in 1999,2000,2008,2009,and 2012.Study findings also revealed a drop in the vegetative cover by 33.3%in the year 2000.Furthermore,the most significant shrinkage in water bodies was observed in the Lake Darbandikhan(LDK),which lost 40.5%of its total surface area in 2009.The statistical analyses revealed that precipitation was significantly positively correlated with the SPI and the surface area of the LDK(correlation coefficients of 0.92 and 0.72,respectively).The relationship between SPI and NDVI-based vegetation cover was positive but not significant.Low precipitation did not always correspond to vegetative drought;the delay of the effect of precipitation on NDVI was one year. 展开更多
关键词 climate change DROUGHT Normalized difference Vegetation index(NDVI) Normalized difference Water index(NDWI) Standardized Precipitation index(SPI) delay effect
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Retrospective analysis of two northern California wild-land fires via Landsat five satellite imagery and Normalized Difference Vegetation Index (NDVI) 被引量:1
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作者 Bennett Sall Michael W. Jenkins James Pushnik 《Open Journal of Ecology》 2013年第4期311-323,共13页
Wild-land fires are a dynamic and destructive force in natural ecosystems. In recent decades, fire disturbances have increased concerns and awareness over significant economic loss and landscape change. The focus of t... Wild-land fires are a dynamic and destructive force in natural ecosystems. In recent decades, fire disturbances have increased concerns and awareness over significant economic loss and landscape change. The focus of this research was to study two northern California wild-land fires: Butte Humboldt Complex and Butte Lightning Complex of 2008 and assessment of vegetation recovery after the fires via ground based measurements and utilization of Landsat 5 imagery and analysis software to assess landscape change. Multi-temporal and burn severity dynamics and assessment through satellite imagery were used to visually ascertain levels of landscape change, under two temporal scales. Visual interpretation indicated noticeable levels of landscape change and relevant insight into the magnitude and impact of both wild-land fires. Normalized Burn Ratio (NBR) and delta NBR (DNBR) data allowed for quantitative analysis of burn severity levels. DNBR results indicate low severity and low re-growth for Butte Humboldt Complex “burned center” subplots. In contrast, DNBR values for Butte Lightning Complex “burned center” subplots indicated low-moderate burn severity levels. 展开更多
关键词 Wild-Land Fire BURN Severity Vegetation Recovery Normalized difference VEGETATIVE index (NDVI) Normalized BURN Ratio (NBR)
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Physicochemical composition and climate response of surface sediments at different altitudes in Motuo on the southern slope of the Himalayas
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作者 XIE Mengping SONG Yougui +2 位作者 LAN Minwen ZHANG Mingyu HAN Yixiao 《地球环境学报》 CSCD 2024年第4期624-640,共17页
Background,aim,and scope Certain physicochemical indexes of topsoil are closely related to climatic factors including temperature,and precipitation.Understanding the relationship between modern topsoil properties and ... Background,aim,and scope Certain physicochemical indexes of topsoil are closely related to climatic factors including temperature,and precipitation.Understanding the relationship between modern topsoil properties and climatic factors is essential for quantitative paleoclimate reconstruction.Motuo located in the eastern Himalayas,exhibits a significant elevation gradient of over 7000 m from Nnamjagbarwa Peak(7782 m a.s.l.)to the Baxika(150 m a.s.l.).This region features a complete vertical zonation of vegetation,from alpine meadow to tropical forest,presenting an ideal place to investigate the relationships among vegetation,soil and climate conditions across altitudinal gradients.This study aims to explore the vertical variations in the physicochemical composition of topsoil and its relationship with temperature and precipitation.Materials and methods Twenty-seven topsoil samples were collected at 100 m intervals from 800 m to 3600 m a.s.l.along the southern slope of the Himalayas.Grain size,magnetic susceptibility and geochemical elements were measured to discuss the vertical variation characteristics of topsoil composition and their correlation with climatic factors.Results(1)The grain size of topsoil at different altitudes in Motuo is mainly composed of sand accounting for an averaged 53.2%,followed by silt and clay.(2)In the mixed forest zone,frequency dependent magnetic susceptibility(χfd%)shows a clear relationship with altitude,and clay is positively correlated with both altitude and climatic factors.(3)The oxides of topsoil in this area mainly consist of SiO_(2),Al_(2)O_(3) and Fe_(2)O_(3),followed by MgO,CaO,Na_(2)O and K_(2)O,with slight variations in the primary components at different altitudes.The sensitivity of elements to climate varies across different altitudes and vegetation zone,likely due to the region’s complex topography and vegetation.(4)Physical and biological weathering dominates in the broad-leaved forest zone of Motuo,while chemical weathering is more prominent in the coniferous forest zone,with the mixed forest zone falling in between.Discussion The formation of topsoil across the three vegetation zones is influenced by various factors,including parent material,vegetation,and climate.In the broad-leaved forest zone,physical weathering(precipitation,root wedging etc.)and pedogenesis dominate,resulting in finer grain size.The χ_(fd)% increases with altitude likely due to the high temperature and abundant precipitation in this zone,which facilitate the transformation of strong magnetic miners into weaker ones,particularly when the soil is oversaturated.Zirconium(Zr),primarily found in zircon,is depleted at lower altitudes by strong current erosion.Barium(Ba)is similarly reduced at low altitudes in this zone.In mixed forest zone,clay content is the lowest,indicating weaker physical weathering conditions than broad-leaved forest zone.The coarser grain size may result from the combined effects of topography and vegetation coverage.Magnetic susceptibility and organic matter show a positive correlation with altitude.Zr concentration is higher than that in the broad-leaved forest zone,likely resulting from decreased precipitation.In the coniferous zone,the clay content shows considerable fluctuations,with grain size generally becoming finer as altitude increases.This trend may be explained by intensified soil disintegration from seasonal freeze-thaw cycles.The χ_(fd)% values lack a clear trend or pattern,possibly due to soil erosion causing the migration of magnetic minerals or insufficient iron precipitation,which reduces the concentration of magnetic minerals in the soil.Additionally,a positive correlation is observed between altitude and organic matter content,with higher altitudes associated with greater organic matter accumulation.This may be attributed to lower microbial activity in colder conditions,which slows the decomposition and transformation of organic matter.Conclusions The variations in grain size,magnetic susceptibility,and geochemical elements differ across altitudes and vegetation zones,closely connected to the complex interplay of terrain,vegetation,and climate in Motuo.In the mixed forest,altitude has a significant impact onχfd%,and the clay component is particularly sensitive to changes in altitude,mean annual temperature,and precipitation.Zr shows a strong correlation with altitude and climate factors,making it a valuable indicator for assessing changes in atmospheric precipitation within specific altitude ranges.Recommendations and perspectives This study enhances our understanding of the relationships between the physicochemical properties of topsoil and climate conditions,offering valuable insights for paleoclimate reconstruction in Motuo. 展开更多
关键词 southern slope of the Himalayas MOTUO TOPSOIL altitude difference vegetation zone physicochemical indexes
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Gini Index for Cities: A Preliminary Study on Regional Differences of Chinese City Size Distribution
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作者 Liu Wangbao & Zheng Bohong Department of Architecture and Urban Planing, Central South University, Changsha 410075, Hunan 《Chinese Journal of Population,Resources and Environment》 2004年第4期33-36,共4页
City size distribution is of interest because of a number of key stylized facts, including notably Zipf's law for cities and the importance of urban primacy. But a new and more efficient method Gini index can be u... City size distribution is of interest because of a number of key stylized facts, including notably Zipf's law for cities and the importance of urban primacy. But a new and more efficient method Gini index can be used for calculating regional city size distribution. This paper begins by developing a calculation method for the Gini index, dividing the whole country into 26 areas and then calculating each area's Gini index value. Based on these calculation results, this paper gives a preliminary study on regional differences of its city size distribution and the dynamics. 展开更多
关键词 Gini index city size distribution regional differences
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Association between Systolic Blood Pressure Difference ≥10 mm Hg and Ankle-Brachial Index
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作者 Shinji Maeda Yuzo Okumura Naohiko Hara 《International Journal of Clinical Medicine》 2016年第5期361-369,共9页
Background: In new outpatients, blood pressure should be measured in both arms. A previous study reported that an inter-arm systolic blood pressure difference (ΔSBP) of ≥10 mm Hg is associated with an increased risk... Background: In new outpatients, blood pressure should be measured in both arms. A previous study reported that an inter-arm systolic blood pressure difference (ΔSBP) of ≥10 mm Hg is associated with an increased risk of mortality. Aim: The aim was to identify the associations with absolute values of ΔSBP (|ΔSBP|) ≥10 mm Hg. Subjects and Methods: This study included 2481 patients. Patients with a body mass index ≥25 kg/m<sup>2</sup> were defined as obese. The group of A was defined as following: ankle-brachial index (ABI) was <0.9 or ≥1.3. ΔSBP was expressed as right arm BP minus left arm BP. |ΔSBP| ≥10 mm Hg were analyzed using multivariate logistic analysis. Results: |ΔSBP| ≥10 mm Hg was found in 6.0% of patients and |ΔSBP| < 5 mm Hg in 80.4%. In multivariate analysis, the odds ratios (ORs) of the associations with |ΔSBP| ≥10 mm Hg were significantly associated with abnormal ABI and obesity regardless of sex and age. Moreover, the OR of the combined effects of abnormal ABI and obesity was higher than that of abnormal ABI and obesity alone. Conclusion: |ΔSBP| ≥10 mm Hg was associated with abnormal ABI and obesity. In a primary care setting, blood pressure should be actively measured in both arms. This study suggests that the associations with |ΔSBP| ≥10 mm Hg may be a useful part of screening for abnormal ABI. 展开更多
关键词 Systolic Blood Pressure difference Ankle-Brachial index OBESITY Odds Ratio Combined Effects
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Soil Carbon Pool Management Index under Different Straw Retention Regimes 被引量:5
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作者 曾研华 吴建富 +4 位作者 何虎 潘晓华 石庆华 吴自明 邓伟明 《Agricultural Science & Technology》 CAS 2012年第4期818-822,共5页
[Objective] To clarify the effects of different straw retention regimes on soil fertility in double cropping paddy field. [Method] The effects of different straw reten- tion regimes on total organic carbon (CToc), a... [Objective] To clarify the effects of different straw retention regimes on soil fertility in double cropping paddy field. [Method] The effects of different straw reten- tion regimes on total organic carbon (CToc), active carbon (CA) and mineralized carbon (CM) were analyzed, and carbon pool active (A), carbon pool active index (A/), carbon pool index (CPI) and carbon pool management index (CPMi) for each treat- ment were calculated. [Result] Compared with the unfertilized treatment (CK), CToc, CA, CM and the available ratio of soil carbon were increased in the treatment of re- turning early season and late season rice straws to field. With the same nutrient application, CToc, CA and the available ratio of soil carbon in the field with straw re- turned to field were higher than that of straw incineration and no straw returning, and the change in soil CA content was more significant. The difference in CPMI be- tween different treatments reached significant or very significant level, and the value was in the order of straw directly returned to field 〉 straw returned to field after in- cineration 〉 no straw returned to field. [Conclusion] This study provided theoretical bases for the increase of soil CA content and soil fertility in double rice fields. 展开更多
关键词 Double-cropping paddy field different straw retention regimes Total or- ganic carbon Active carbon Mineralized carbon Carbon pool management index
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THE STUDY OF DIFFERENCE OF PCNA LABELLED CELL INDEXES BETWEEN ENDOMETRIA OF HUMAN AND MOUSE
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作者 Miao Naizhou Shi Xiaolin Liang Yuanjing et al(Department of Histology a,ld Embryology, Yan’an Medical College) 《Journal of Pharmaceutical Analysis》 CAS 1998年第1期53-53,共1页
40 human endometrial tissues of benign diseases were diviided into 8 groups (phases),and 50 BDF1 mousy endometrial tissues were divided into 5 groups (phases).Immunohistochenical staining was performed to show the PCN... 40 human endometrial tissues of benign diseases were diviided into 8 groups (phases),and 50 BDF1 mousy endometrial tissues were divided into 5 groups (phases).Immunohistochenical staining was performed to show the PCNA (proliferating cell nuclear antigen)positive cell .In human ,the results suggested that the PCNA layer(48%)of mid-proliferative hpase.The PCNA labelled index was low in superficial epithelium.But in mouse, the results suggested that the Pcna labelled index was the highest(22%)in endometrium of estrus and the labelled cells were distributed mainly in superficial epithelium (60%).The results suggested that times that times and positions of cellular proliferation in endometrial tissues of human and mouse differed greatly. 展开更多
关键词 PCNA THE STUDY OF difference OF PCNA LABELLED CELL indexES BETWEEN ENDOMETRIA OF HUMAN AND MOUSE
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Temporal and spatial differences and imbalance of China's urbanization development during 1950-2006 被引量:7
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作者 方创琳 刘晓丽 《Journal of Geographical Sciences》 SCIE CSCD 2009年第6期719-732,共14页
A better understanding of the regional disparity and imbalance characteristics of China's urbanization development is the important premise for constituting correct policy and strategy and promoting the healthy an... A better understanding of the regional disparity and imbalance characteristics of China's urbanization development is the important premise for constituting correct policy and strategy and promoting the healthy and sustainable development of urbanization in the 21st century. The regional differences of China's urbanization level have close relations with natural conditions of landform and climate etc.,the urbanization level reduces with the eleva-tion of topography and decrease of precipitation. According to the statistical data set of ur-banization in 1950-2006,the temporal change course of inter-provincial disparity of Chinese urbanization level since the founding of New China in 1949 was studied,and then the inter-regional and intra-regional disparities of urbanization development were analyzed by the Theil index and its nested decomposition method,to grasp the dynamic change of spatial disparities of China's urbanization level on the whole. Using the imbalance index model,the imbalance status of urban population distribution relative to total population,grain output,total agricultural output value,gross output value of industry,tertiary industrial output value as well as gross regional product was discussed,to hold the balance characteristics of urbanization development relative to the regional development conditions from the macroscopic scales. 展开更多
关键词 URBANIZATION difference imbalance index China
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Mean Difference of Truncated Normal Distribution
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作者 Giovanni Girone Antonella Massari +1 位作者 Fabio Manca Claudia Marin 《Applied Mathematics》 2020年第11期1162-1166,共5页
The purpose of this paper is to broaden the knowledge of mean difference and, in particular, of an important distribution model known as truncated normal distribution, which is widely used in applied sciences and econ... The purpose of this paper is to broaden the knowledge of mean difference and, in particular, of an important distribution model known as truncated normal distribution, which is widely used in applied sciences and economics. In this work, we obtained the general formula of mean difference, which is not yet reported in literature, for the aforementioned distribution model and also for particular truncated cases. 展开更多
关键词 Mean difference Truncated Normal Distribution Variability indexes Economic Sciences
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Mean Difference and Mean Deviation of Tukey Lambda Distribution
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作者 Giovanni Girone Antonella Massari +1 位作者 Fabio Manca Angela Maria D’Uggento 《Applied Mathematics》 2020年第8期771-778,共8页
The purpose of this paper is to broaden the knowledge of mean difference and,<span><span><span style="font-family:;" "=""> </span></span></span><span sty... The purpose of this paper is to broaden the knowledge of mean difference and,<span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">in particular, of an important distribution model known as Tukey lambda, which is generally used to choose a model to fit data.</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">We have obtained compact formulas, which are not yet reported in literature, of mean deviation and mean difference related to the said distribution model.</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">These results made it possible to analyze the relationships among variability indexes, namely standard deviation, mean deviation and mean difference, regarding Tukey lambda model.</span></span></span> 展开更多
关键词 Mean difference Mean Deviation Tukey Lambda Distribution Variability indexes’ Relationships
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Migrated Exploding Reflectors in Evaluation of Finite Difference Solution for Inhomogeneous Seismic Models
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作者 Maryam Nejati Hosein Hashemi 《Engineering(科研)》 2012年第12期950-957,共8页
Earth is inhomogeneous, which means its elastic characteristics change with depth. The seismic method employs the propagation of waves throughout the earth to locate different structures and stratigraphy. Understandin... Earth is inhomogeneous, which means its elastic characteristics change with depth. The seismic method employs the propagation of waves throughout the earth to locate different structures and stratigraphy. Understanding the wave propagation is an important matter in exploration seismology;therefore modeling of seismic wave is an important tool. To validate the interpreted earth model out of the seismic data, seismic synthetic seismograms should be generated in a process named “seismic forward modeling”. Finite difference method is used as one of the most common numerical modeling techniques. In this paper the accuracy of finite difference method in seismic section modeling is explored on different modeled data set of heterogeneous earth. It is shown that finite difference method completes with migration to reposition the events in their correct location. Two different migration methods are used and various velocities are also tested to determine an appropriate migration velocity. Finally the validly of finite difference modeling is examined using a 2D structural similarity index technique. 展开更多
关键词 Finite difference Method SEISMIC Modeling Migration Exploding REFLECTOR Structural SIMILARITY index
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Internal Spatial Differences in a Large Country: Consumer Price and Inequalities
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作者 Song Ze Liu Zilan Zou Hong 《China Economist》 2021年第4期101-114,共14页
Unbalanced price changes across regions cause consumption inequalities within a large country.With consumer demand system model,this paper estimated the dynamic changes of the true-cost-of-living index(TCLI)and consum... Unbalanced price changes across regions cause consumption inequalities within a large country.With consumer demand system model,this paper estimated the dynamic changes of the true-cost-of-living index(TCLI)and consumption inequalities in China.Results indicate urban households experienced a rising TCLI from 2002 to 2014,among which,Liaoning increased the most and Guangdong the least.Beijing’s TCLI was the highest and Sichuan the lowest over the same period.Since 2008,the unbalanced rise of consumer price has gradually diminished,and gaps between real and nominal consumption inequalities have narrowed.However,real consumption inequalities continue to rise,and low-income groups are affected the most by inflation. 展开更多
关键词 spatial price differences true-cost-of-living index consumption inequalities
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Monitoring vegetation drought in the nine major river basins of China based on a new developed Vegetation Drought Condition Index
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作者 ZHAO Lili LI Lusheng +4 位作者 LI Yanbin ZHONG Huayu ZHANG Fang ZHU Junzhen DING Yibo 《Journal of Arid Land》 SCIE CSCD 2023年第12期1421-1438,共18页
The effect of global climate change on vegetation growth is variable.Timely and effective monitoring of vegetation drought is crucial for understanding its dynamics and mitigation,and even regional protection of ecolo... The effect of global climate change on vegetation growth is variable.Timely and effective monitoring of vegetation drought is crucial for understanding its dynamics and mitigation,and even regional protection of ecological environments.In this study,we constructed a new drought index(i.e.,Vegetation Drought Condition Index(VDCI))based on precipitation,potential evapotranspiration,soil moisture and Normalized Difference Vegetation Index(NDVI)data,to monitor vegetation drought in the nine major river basins(including the Songhua River and Liaohe River Basin,Haihe River Basin,Yellow River Basin,Huaihe River Basin,Yangtze River Basin,Southeast River Basin,Pearl River Basin,Southwest River Basin and Continental River Basin)in China at 1-month–12-month(T1–T12)time scales.We used the Pearson's correlation coefficients to assess the relationships between the drought indices(the developed VDCI and traditional drought indices including the Standardized Precipitation Evapotranspiration Index(SPEI),Standardized Soil Moisture Index(SSMI)and Self-calibrating Palmer Drought Severity Index(scPDSI))and the NDVI at T1–T12 time scales,and to estimate and compare the lag times of vegetation response to drought among different drought indices.The results showed that precipitation and potential evapotranspiration have positive and major influences on vegetation in the nine major river basins at T1–T6 time scales.Soil moisture shows a lower degree of negative influence on vegetation in different river basins at multiple time scales.Potential evapotranspiration shows a higher degree of positive influence on vegetation,and it acts as the primary influencing factor with higher area proportion at multiple time scales in different river basins.The VDCI has a stronger relationship with the NDVI in the Songhua River and Liaohe River Basin,Haihe River Basin,Yellow River Basin,Huaihe River Basin and Yangtze River Basin at T1–T4 time scales.In general,the VDCI is more sensitive(with shorter lag time of vegetation response to drought)than the traditional drought indices(SPEI,scPDSI and SSMI)in monitoring vegetation drought,and thus it could be applied to monitor short-term vegetation drought.The VDCI developed in the study can reveal the law of unclear mechanisms between vegetation and climate,and can be applied in other fields of vegetation drought monitoring with complex mechanisms. 展开更多
关键词 vegetation drought Vegetation Drought Condition index(VDCI) Normalized difference Vegetation index(NDVI) vegetation dynamics climate change China
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Study of Difference-Expansion Embedding Schemes
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作者 Ke Mao Chin-Feng Lee +1 位作者 Chin-Cheng Chang Run-Hua Shi 《Journal of Electronic Science and Technology》 CAS CSCD 2017年第3期211-216,共6页
Difference expansion(DE) is one of the famous schemes in the field of reversible data hiding.With the high efficiency and simplicity,DE also has received more attention over the years.DE has a good information capac... Difference expansion(DE) is one of the famous schemes in the field of reversible data hiding.With the high efficiency and simplicity,DE also has received more attention over the years.DE has a good information capacity,but due to its major location map,the pure payload is rather low.Therefore many scholars did relevant improvements which let n pixels as a unit instead of the original two pixels as a unit and can adaptively adjust the number of embedding secret information according to the smoothness degree of the block,which achieves the result of improving the information payload or the image quality.In this paper,the study of DE-based reversible data hiding schemes is comprehensively discussed.The performance of DEbased schemes is evaluated and compared in terms of embedding capacity and stego-image quality. 展开更多
关键词 index Terms-difference expansion integertransform reversible data hiding STEGANOGRAPHY
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