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Short-Impending Earthquake Anomaly Index Extraction of GNSS Continuous Observation Data in Yunnan,Southwestern China 被引量:13
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作者 Min Hong Desheng Shao +4 位作者 Tengfei Wu Shuangxi Zhang Yong Zhang Lingli Wang Xiaodong Qian 《Journal of Earth Science》 SCIE CAS CSCD 2018年第1期230-236,共7页
This paper presents a comprehensive area expansion prediction index method to apply GNSS for short-impending prediction of earthquakes. Based on continuous GNSS observation data from Yunnan Province, a displacement fi... This paper presents a comprehensive area expansion prediction index method to apply GNSS for short-impending prediction of earthquakes. Based on continuous GNSS observation data from Yunnan Province, a displacement field was detected after data cycle-slip repair using precision data processing software and geophysical field effect model correction. The Yunnan area was divided into 56 grid cells for displacement field interpolation to obtain a more uniform displacement field and a strain field variation time series. The pre-earthquake response of each grid-cell expansion time series was evaluated and synthesized to extract a short-impending earthquake anomaly identification index. The results show that this index indicated occurrence times and hypocenter for earthquakes of magnitude M≥5. Fourteen earthquakes were predicted accurately, and there were five false reports. This index can therefore be used for the short-impending prediction of earthquakes. 展开更多
关键词 GNSS short-impending earthquake prediction strain anomaly index southwestern China.
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Matter-element models for comprehensive earthquake predication and their applications 被引量:1
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作者 蒋淳 陈化然 +1 位作者 田山 王建国 《Acta Seismologica Sinica(English Edition)》 CSCD 2000年第4期448-453,共6页
Extenics was a branch of mathematics for studying the incompatible problems. In this paper, basing on calculating the associative functions of all various indexes, we have obtained the quantitative assessment results ... Extenics was a branch of mathematics for studying the incompatible problems. In this paper, basing on calculating the associative functions of all various indexes, we have obtained the quantitative assessment results of prediction indexes by introducing this theory into the comprehensive earthquake prediction through establishing the matter-element model for comprehensive prediction, so that the incompatible problems can be solved. The preliminary results demonstrate that this method has better prospects in comprehensive earthquake prediction. 展开更多
关键词 EXTENICS comprehensive prediction model associative function anomaly index
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Effects of Drought on Net Primary Productivity:Roles of Temperature,Drought Intensity,and Duration 被引量:4
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作者 SUN Binfeng ZHAO Hong WANG Xiaoke 《Chinese Geographical Science》 SCIE CSCD 2016年第2期270-282,共13页
Northeast China has experienced frequent droughts over the past fifteen years. However, the effects of droughts on net primary productivity(NPP) in Northeast China remain unclear. In this paper, the droughts that occu... Northeast China has experienced frequent droughts over the past fifteen years. However, the effects of droughts on net primary productivity(NPP) in Northeast China remain unclear. In this paper, the droughts that occurred in Northeast China between 1999 and 2013 were identified using the Standardized Precipitation Evapotranspiration Index(SPEI). The NPP standardized anomaly index(NPP-SAI) was used to evaluate NPP anomalies. The years of 1999, 2000, 2001, and 2007 were further investigated in order to explore the influence of droughts on NPP at different time scales(3, 6, and 12 months). Based on the NPP-SAI of normal areas, we found droughts overall decreased NPP by 112.06 Tg C between 1999 and 2013. Lower temperatures at the beginning of the growing season could cause declines in NPP by shortening the length of the growing season. Mild drought or short-term drought with higher temperatures might increase NPP, and weak intensity droughts intensified the lag effects of droughts on NPP. 展开更多
关键词 drought net primary productivity(NPP) Standardized Precipitation Evapotranspiration index(SPEI) NPP Standardized anomaly index(NPP-SAI)
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Assessing human sperm morphology: top models, underdogs or biometrics? 被引量:15
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作者 Jacques Auger 《Asian Journal of Andrology》 SCIE CAS CSCD 2010年第1期36-46,共11页
The assessment of the percentage of spermatozoa having an 'ideal' morphology using so-called strict method is the method recommended in the latest edition of the World Health Organization (WHO) laboratory manual f... The assessment of the percentage of spermatozoa having an 'ideal' morphology using so-called strict method is the method recommended in the latest edition of the World Health Organization (WHO) laboratory manual for semen analysis. This recommendation is a result of the statistical association between 'ideal' sperm morphology and fertility, and of the current general belief that sperm morphology assessment should be used primarily as a fertility tool. The notion of an 'ideal' sperm morphology has persisted despite the very low percentage of such spermatozoa in the semen of fertile men, a subject of intense controversy. The detailed categorization of each abnormal spermatozoon has thus, for a long time, been considered optional and partially redundant, an idea which is reflected in the earlier editions of the WHO manual. However, several recent studies have shown the importance of carefully assessing abnormal sperm morphology for use in the diagnosis &infertility, to determine fertility prognosis, and for basic or public health studies. One approach, which combines videomicroscopy and computer vision, and is the only approach able to assess the continuum of sperm biometrics, has been used successfully in several recent clinical, basic and toxicology studies. In summary, the visual assessment of detailed sperm morphology--including the categorization of anomalies allowing arithmetically derived indices of teratozoospermia--and the more modern computer-based approaches, although often considered to be redundant, are in fact complementary. The choice of the most appropriate method depends on the field of investigation (clinical, research, toxicology) and the problem being addressed. Each approach has advantages as well as certain limitations, which will be discussed briefly herein. 展开更多
关键词 diagnosis fertility prognosis image analysis multiple anomalies index pattern recognition reproductive toxicology spermdefects sperm deformity index sperm pathology teratozoospermic index VIDEOMICROSCOPY
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Long Term Spatio-temporal Variations of Seasonal and Decadal Aridity in India
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作者 Pavan Kumar B Bhavani Pinjarla +1 位作者 P K Joshi P S Roy 《Journal of Atmospheric Science Research》 2021年第3期29-45,共17页
A comprehensive analysis of climate data(1958-2018)is carried out at the national scale in India to assess spatiotemporal variation in aridity.The aridity is analyzed using UNEP(United Nations Environment Programme)Ar... A comprehensive analysis of climate data(1958-2018)is carried out at the national scale in India to assess spatiotemporal variation in aridity.The aridity is analyzed using UNEP(United Nations Environment Programme)Aridity Index(AI),which is the ratio between Precipitation(P)and Potential Evapotranspiration(PET).Freely available Terra-Climate database,P and PET variables,offered an unprecedented opportunity for monitoring variations in AI and aridity index anomalies(AIA)at inter-seasonal and inter-decadal basis.The study also assesses longer term patterns of P and AI anomalies with vegetation anomalies.The results indicate that significant clustered areas with maximum dryness are located at west-central part of India,the state of Maharashtra.Overall,there is a gradual increase in the extent of arid zone during 60-year period and spatially maximum extent of percentage change in aridity area is observed.The change patterns of AI in India are largely driven by the changing patterns of precipitation.The maximum impact of decline in precipitation on AIA was observed during Kharif season frequently,for every 4-5 years during 1972-1992.The pattern repeated in the last few recent years(2013-2018),the decline in precipitation resulted increased aridity.The study also reveals that the availability and usage of irrigation sources have increased from 2014 to 2018.Thus,despite of less precipitation positive vegetation has been resulted in this period.The findings are important to understand the impacts of climate change on land use pattern,and land and water resource management. 展开更多
关键词 Aridity index Aridity index anomaly NDVI Potential evapotranspiration Precipitation SPI
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Detecting Effects of the Recent Drought on Vegetation in Southwestern China 被引量:5
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作者 张景华 姜鲁光 +1 位作者 封志明 李鹏 《Journal of Resources and Ecology》 CSCD 2012年第1期43-49,共7页
The severest drought on record occurred in southwestern China from September 2009 until March 2010. In order to measure the impact the drought imposed on vegetation, we developed an evaluation indicator called the Veg... The severest drought on record occurred in southwestern China from September 2009 until March 2010. In order to measure the impact the drought imposed on vegetation, we developed an evaluation indicator called the Vegetation Index Anomaly (VIA) based on MODIS/EVI. The tempo- spatial pattern of this impact was analyzed. Given that this impact may be modulated by many factors, the responses of different vegetation types (woodland, grassland and cropland), and the spatial pattern of meteorological drought were also analyzed. Results show that more than 50% of vegetation suffered because of this drought event, but there was significant tempo-spatial variability in the range and intensity of impact. This variability may be caused by many factors. Of the three major vegetation types, cropland was the most sensitive to drought, followed by grassland and then woodland. In addition, meteorological factors (precipitation and air temperature) also played a role; however, obvious differences exist between the spatial distribution pattern of drought-stricken vegetation and that of meteorological drought, which further demonstrates the intervention of other factors besides meteorological factors. So compared to meteorological drought, the vegetation index may be more useful for measuring the actual intensity, duration and impact of drought events. The limitations of vegetation indices are also considered. 展开更多
关键词 NDVI EVI Vegetation index anomaly drought monitoring Southwestern China
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