单位捕捞努力量渔获量(Catch Per Unit Effort,CPUE)是资源评估的前提和基础,为了更好地评估西北印度洋鸢乌贼资源,采用广义加性模型(generalized additive model,GAM)对2016~2020年西北印度洋鸢乌贼的CPUE进行了标准化。结果显示,月份...单位捕捞努力量渔获量(Catch Per Unit Effort,CPUE)是资源评估的前提和基础,为了更好地评估西北印度洋鸢乌贼资源,采用广义加性模型(generalized additive model,GAM)对2016~2020年西北印度洋鸢乌贼的CPUE进行了标准化。结果显示,月份、海表温度(sea surface temperature,SST)、海面高度(sea surface height,SSH)、经度和纬度对CPUE呈显著性影响,通过对不同GAM模型的AIC (Akaike information criterion)值比较,由月份、SST、SSH、经度和纬度5个因子构成的GAM模型为最优CPUE标准化模型,对CPUE偏差的解释率为40.3%。研究表明,西北印度洋鸢乌贼高CPUE主要出现在9月至翌年3月,海域范围为16°~19°N、60°~65°E,SST为25~28°C、SSH为0.2~0.4 m的海域内。整体而言,标准化CPUE低于名义CPUE,但二者的变化趋势基本一致。展开更多
Landslides are the most common natural disaster in hilly terrain which causes changes in landscape and damage to life and property. The main objective of the present study was to carry out landslide hazard zonation ma...Landslides are the most common natural disaster in hilly terrain which causes changes in landscape and damage to life and property. The main objective of the present study was to carry out landslide hazard zonation mapping on 1:50,000 scale along ghat road section of Kolli hills using a Landslide Hazard Evaluation Factor(LHEF) rating scheme. The landslide hazard zonation map has been prepared by overlaying the terrain evaluation maps with facet map of the study area. The terrain evaluation maps include lithology, structure, slope morphometry, relative relief, land use and land cover and hydrogeological condition. The LHEF rating scheme and the Total Estimated Hazard(TEHD) were calculated as per the Bureau of Indian Standard(BIS) guidelines(IS: 14496(Part-2) 1998) for the purpose of preparation of Landslide Hazard Zonation(LHZ) map in mountainous terrains. The correction due to triggering factors such as seismicity, rainfall and anthropogenic activities were also incorporated with Total Estimated Hazard to get final corrected TEHD. The landslide hazard zonation map was classified as the high, moderate and low hazard zones along the ghat road section based on corrected TEHD.展开更多
In this technical paper,we will discuss polyurethane linings and coatings to ductile iron pipe for transporting corrosive and abrasive fluids in a sub soil,that is extremely corrosive in nature.The capabilities of ECL...In this technical paper,we will discuss polyurethane linings and coatings to ductile iron pipe for transporting corrosive and abrasive fluids in a sub soil,that is extremely corrosive in nature.The capabilities of ECL(Electrosteel Castings Limited)in this regard will be discussed.展开更多
Concrete is one of the most consumable construction materials on the earth.The concrete constitutes cement,sand,gravel,water and/or additives in definite proportions.The proportions of raw materials of concrete are de...Concrete is one of the most consumable construction materials on the earth.The concrete constitutes cement,sand,gravel,water and/or additives in definite proportions.The proportions of raw materials of concrete are decided by the concrete mix design.The mix design depends on the various factors.For mix design,most of the countries have their own specifications.In the present study,standard guidelines of India,Britain and America for the concrete mix design have been discussed.The concrete grades of M25,M35 and M45 were designed and compared.Indian Standards were also compared.It was concluded that a new revised version of Indian Standard code has the lowest value of water/cement ratio and highest quantity of cement as compared to other standards.展开更多
基于1961—2015年黄土高原57个基准站逐月降水资料,计算标准化降水指数(SPI),将其作为旱涝指标研究4月黄土高原旱涝异常年环流特征及其前期外强迫信号。结果表明:(1)当500 h Pa乌拉尔山至中国新疆高压脊偏强、东亚大槽偏深,700 h Pa黄...基于1961—2015年黄土高原57个基准站逐月降水资料,计算标准化降水指数(SPI),将其作为旱涝指标研究4月黄土高原旱涝异常年环流特征及其前期外强迫信号。结果表明:(1)当500 h Pa乌拉尔山至中国新疆高压脊偏强、东亚大槽偏深,700 h Pa黄土高原及其以东南风偏弱,700 h Pa中国东部至日本温度偏低,中国东部到日本以东洋面西风急流南压加强时,黄土高原易旱,反之易涝。(2) 4月北半球中高纬度150°W—180°E区域异常涝年阻塞出现次数多于异常旱年。(3)南印度洋偶极子(SIOD)或西南印度洋海温可以作为4月旱涝的前期强迫信号,4月SPI与前一年12月SIOD存在显著负相关关系。(4)黄土高原旱涝对SIOD正负位相异常的响应主要反映在500 h Pa乌拉尔山高压脊、东亚大槽以及700 h Pa贝加尔湖至中国东北以及乌拉尔山的环流差异上。展开更多
文摘单位捕捞努力量渔获量(Catch Per Unit Effort,CPUE)是资源评估的前提和基础,为了更好地评估西北印度洋鸢乌贼资源,采用广义加性模型(generalized additive model,GAM)对2016~2020年西北印度洋鸢乌贼的CPUE进行了标准化。结果显示,月份、海表温度(sea surface temperature,SST)、海面高度(sea surface height,SSH)、经度和纬度对CPUE呈显著性影响,通过对不同GAM模型的AIC (Akaike information criterion)值比较,由月份、SST、SSH、经度和纬度5个因子构成的GAM模型为最优CPUE标准化模型,对CPUE偏差的解释率为40.3%。研究表明,西北印度洋鸢乌贼高CPUE主要出现在9月至翌年3月,海域范围为16°~19°N、60°~65°E,SST为25~28°C、SSH为0.2~0.4 m的海域内。整体而言,标准化CPUE低于名义CPUE,但二者的变化趋势基本一致。
基金the Natural Resources Data Management System (NRDMS),Department of Science and Technology, New Delhi, to sponsor the project
文摘Landslides are the most common natural disaster in hilly terrain which causes changes in landscape and damage to life and property. The main objective of the present study was to carry out landslide hazard zonation mapping on 1:50,000 scale along ghat road section of Kolli hills using a Landslide Hazard Evaluation Factor(LHEF) rating scheme. The landslide hazard zonation map has been prepared by overlaying the terrain evaluation maps with facet map of the study area. The terrain evaluation maps include lithology, structure, slope morphometry, relative relief, land use and land cover and hydrogeological condition. The LHEF rating scheme and the Total Estimated Hazard(TEHD) were calculated as per the Bureau of Indian Standard(BIS) guidelines(IS: 14496(Part-2) 1998) for the purpose of preparation of Landslide Hazard Zonation(LHZ) map in mountainous terrains. The correction due to triggering factors such as seismicity, rainfall and anthropogenic activities were also incorporated with Total Estimated Hazard to get final corrected TEHD. The landslide hazard zonation map was classified as the high, moderate and low hazard zones along the ghat road section based on corrected TEHD.
文摘In this technical paper,we will discuss polyurethane linings and coatings to ductile iron pipe for transporting corrosive and abrasive fluids in a sub soil,that is extremely corrosive in nature.The capabilities of ECL(Electrosteel Castings Limited)in this regard will be discussed.
文摘Concrete is one of the most consumable construction materials on the earth.The concrete constitutes cement,sand,gravel,water and/or additives in definite proportions.The proportions of raw materials of concrete are decided by the concrete mix design.The mix design depends on the various factors.For mix design,most of the countries have their own specifications.In the present study,standard guidelines of India,Britain and America for the concrete mix design have been discussed.The concrete grades of M25,M35 and M45 were designed and compared.Indian Standards were also compared.It was concluded that a new revised version of Indian Standard code has the lowest value of water/cement ratio and highest quantity of cement as compared to other standards.
文摘基于1961—2015年黄土高原57个基准站逐月降水资料,计算标准化降水指数(SPI),将其作为旱涝指标研究4月黄土高原旱涝异常年环流特征及其前期外强迫信号。结果表明:(1)当500 h Pa乌拉尔山至中国新疆高压脊偏强、东亚大槽偏深,700 h Pa黄土高原及其以东南风偏弱,700 h Pa中国东部至日本温度偏低,中国东部到日本以东洋面西风急流南压加强时,黄土高原易旱,反之易涝。(2) 4月北半球中高纬度150°W—180°E区域异常涝年阻塞出现次数多于异常旱年。(3)南印度洋偶极子(SIOD)或西南印度洋海温可以作为4月旱涝的前期强迫信号,4月SPI与前一年12月SIOD存在显著负相关关系。(4)黄土高原旱涝对SIOD正负位相异常的响应主要反映在500 h Pa乌拉尔山高压脊、东亚大槽以及700 h Pa贝加尔湖至中国东北以及乌拉尔山的环流差异上。
