Date pits for feed preparation or oil extraction are soaked in water to soften before milling or extrusion. Knowledge of water absorption by the date pits helps in better managing the soaking duration. In this researc...Date pits for feed preparation or oil extraction are soaked in water to soften before milling or extrusion. Knowledge of water absorption by the date pits helps in better managing the soaking duration. In this research, the process of water absorption by date pits was modeled and analyzed using Fick's second law of diffusion, finite element approach, and Peleg model. The moisture content of the pits reached to its saturation level of 41.5% (wet basis) after 10 d. The estimated coefficient of diffusion was 9.89×10-12 m2/s. The finite element model with a proposed ellipsoid geometry for a single date pit and the analytical model fitted better to the experimental data with R2 of 0.98. The former model slightly overestimated the moisture content of the pits during the initial stages of the soaking and the latter model generally underestimated this variable through the entire stages of soaking process.展开更多
Based on research concerning dynamic relationships of winter wheat growth to environments and production conditions, a winter wheat model for selecting suitable sowing date, population density and sowing rate under di...Based on research concerning dynamic relationships of winter wheat growth to environments and production conditions, a winter wheat model for selecting suitable sowing date, population density and sowing rate under different varieties, spatial and temporal environments was developed. Case studies on sowing date with the data sets of five different eco-sites, three climatic years and soil fertility levels, and on population density and sowing rate with the data sets of two different variety types, three different soil types, soil fertility levels, sowing dates and grain yield levels indicate a good model performance for decision-making.展开更多
Projected changes in weather parameters, mainly temperature and rainfall, have already started to show their effect on agricultural production. To cope with the changing scenarios, adoption of appropriate management s...Projected changes in weather parameters, mainly temperature and rainfall, have already started to show their effect on agricultural production. To cope with the changing scenarios, adoption of appropriate management strategies is of paramount importance. A study was undertaken to evaluate the most appropriate combination of sowing date and phosphorus fertilization level for peanut crops grown in sandy loam soil in a subhumid region of eastern India. Field experiments were conducted during the summer seasons of 2012 and 2013 on peanut crops at the farm of the Indian Institute of Technology, Kharagpur. The DSSAT v4.5 CROPGRO-Peanut model was used to predict the phenology, growth, and yield of peanut crop under combinations of four sowing dates and four phosphorus fertilization levels. The model was calibrated with a 2012 dataset of growth, phenology, and yield parameters for estimating the genetic coefficients of cultivar TMV-2 and was validated with a 2013 dataset of the same parameters. Simulations of pod yield and other yield parameters using the calibrated model were found to be quite accurate. The model was able to reasonably simulate pod yield and final biomass with low normalized root mean square error (RMSE_n), low absolute root mean square error (RMSE_a) and high coefficient of determination (R^2> 0.7) over a wide range of sowing dates and different phosphorus fertilization levels sensitivity analysis indicated that sowing from the second week of January to the end of February with 30–50 kg P_2O_5 ha^(-1)would give the highest pod yield.展开更多
This paper discusses the Rb-Sr geochemical behaviour of illites in the sedimentary process, and points out that illites of the lmd and lm types could reach Sr-isotopic equilibrium with its environmental medium during ...This paper discusses the Rb-Sr geochemical behaviour of illites in the sedimentary process, and points out that illites of the lmd and lm types could reach Sr-isotopic equilibrium with its environmental medium during the sedimentary process and initial stage of diagenesis, and illite grains of different sizes have various Rb contents. A new dating method for sedimentary rocks----a dating model of illite grain Rb-Sr isochron----is established, in consideration of the geochemical process of Sr-isotopic homogenization and differentiation in the course of their formation and evolution. In addition, the paper concerns the application of the dating model to the Precambrian unmetamorphosed sedimentary rocks in western Henan Province, which gives satisfactory results coincident with the geological facts.展开更多
The method to determine the surface albedo using satellite date hasbeen developed and discussed. The relatons betwam the planetary albedo andsurfoce albedo in clear skies are derived with the help of the radiative ...The method to determine the surface albedo using satellite date hasbeen developed and discussed. The relatons betwam the planetary albedo andsurfoce albedo in clear skies are derived with the help of the radiative transfermodelling. To improve the accuracy of the denved surfoce albedo, theparameter X0, i.e., the ratio of the reflected to the total extinction radiation isintroduced into this model. The influences of the model paramenters on thesurfoce albedo have been analyzed. It is found that the error in the derivedsurfoce albedo due to the paramaters together is less than that caused by oulyone parameter because of the complementarity of the parameters. Test resultsin 22 stations over China have been given using the Geostationary SatelliteGMS. The results are generally agreeable except for the case of snow/ice cover.展开更多
地震灾害观测数据多源异构、蕴含知识分散且关联程度低,导致难以高效利用数据进行信息整合和查询,进而提供风险评估、救援决策辅助支持。知识图谱是一种有效的数据关联和融合的手段。首先,基于自顶向下方法梳理地震灾害领域概念,构建地...地震灾害观测数据多源异构、蕴含知识分散且关联程度低,导致难以高效利用数据进行信息整合和查询,进而提供风险评估、救援决策辅助支持。知识图谱是一种有效的数据关联和融合的手段。首先,基于自顶向下方法梳理地震灾害领域概念,构建地震灾害数据、地质/地理环境、地震灾害事件、地震灾害应急任务、地震灾害模型本体,形成地震灾害本体层;结合自底向上方法构建高质量数据层,通过卷积神经网络对遥感影像进行灾害前后变化识别,实现从影像信息到文本知识的智能结构化转换;融合微调后通用信息抽取框架(universal information extraction,简称UIE)预训练模型对文本数据进行命名实体及关系属性知识抽取,精确率分别为82.04%和70.66%。通过计算词向量语义相似度实现数据融合与统一表达。以2023年12月18日甘肃省临夏州积石山县地震为例,通过本体构建、数据抽取、统一表达形成高质量地震灾害知识图谱,实现地震灾害多源异构地震数据到统一知识表达的转化。基于所构建的地震灾害知识图谱实现了灾害损失、应急链决策支持的查询展示,及结合相关地质数据推理和查询潜在次生灾害。该方法结合深度学习与预训练技术,融合多模态数据,构建了地震灾害知识图谱构建,为快速准确的地震灾害信息查询与次生灾害发生提供辅助支撑。展开更多
齐家文化是甘青地区新石器时代晚期至青铜时代早期的文化,是中国最早受欧亚大陆史前文化交流显著影响的重要文化类型,由于缺少对已发表测年数据的系统性研究与评价,对于齐家文化形成年代和发展过程等相关问题的研究仍存在许多不足。本...齐家文化是甘青地区新石器时代晚期至青铜时代早期的文化,是中国最早受欧亚大陆史前文化交流显著影响的重要文化类型,由于缺少对已发表测年数据的系统性研究与评价,对于齐家文化形成年代和发展过程等相关问题的研究仍存在许多不足。本文收集整理了已发表的37个遗址的137个齐家文化^(14)C测年数据,并选择可靠测年的71个植物残体(作物种子)和骨骼测年数据,利用贝叶斯方法建立年代模型,由此推测齐家文化形成时代为4200—3400 cal a B.P.(指距1950年的日历年,即2250―1450aB.C.),结束年龄比过去认为的3500 a B.P.更晚,并发现已发表的炭屑测年存在200~300 a的“老碳”效应。依据新建立的齐家文化年代模型,齐家文化在4200 cal a B.P.首先在甘肃东部的泾河-渭河上游发展,后向西扩散到黄土高原西部、青藏高原东北边缘和河西走廊东段,随后在3800 a B.P.之后重心收缩到青藏高原东北缘地区,推测齐家文化晚期受跨大陆交流影响导致的齐家文化内部分化和转型是齐家文化走向衰亡的原因。展开更多
文摘Date pits for feed preparation or oil extraction are soaked in water to soften before milling or extrusion. Knowledge of water absorption by the date pits helps in better managing the soaking duration. In this research, the process of water absorption by date pits was modeled and analyzed using Fick's second law of diffusion, finite element approach, and Peleg model. The moisture content of the pits reached to its saturation level of 41.5% (wet basis) after 10 d. The estimated coefficient of diffusion was 9.89×10-12 m2/s. The finite element model with a proposed ellipsoid geometry for a single date pit and the analytical model fitted better to the experimental data with R2 of 0.98. The former model slightly overestimated the moisture content of the pits during the initial stages of the soaking and the latter model generally underestimated this variable through the entire stages of soaking process.
基金the National Natural Science Foundation of China(30030090) National“863”Plans of China(2001AA245041,2001AA115420).
文摘Based on research concerning dynamic relationships of winter wheat growth to environments and production conditions, a winter wheat model for selecting suitable sowing date, population density and sowing rate under different varieties, spatial and temporal environments was developed. Case studies on sowing date with the data sets of five different eco-sites, three climatic years and soil fertility levels, and on population density and sowing rate with the data sets of two different variety types, three different soil types, soil fertility levels, sowing dates and grain yield levels indicate a good model performance for decision-making.
基金The authors are thankful to the Agricultural and Food Engineering Department of the Indian Institute of Technology Kharagpur, India for providing facilities to conduct experiments.The authors acknowledge the India Meteorological Department, India for installing an automatic weather stationat the institute.
文摘Projected changes in weather parameters, mainly temperature and rainfall, have already started to show their effect on agricultural production. To cope with the changing scenarios, adoption of appropriate management strategies is of paramount importance. A study was undertaken to evaluate the most appropriate combination of sowing date and phosphorus fertilization level for peanut crops grown in sandy loam soil in a subhumid region of eastern India. Field experiments were conducted during the summer seasons of 2012 and 2013 on peanut crops at the farm of the Indian Institute of Technology, Kharagpur. The DSSAT v4.5 CROPGRO-Peanut model was used to predict the phenology, growth, and yield of peanut crop under combinations of four sowing dates and four phosphorus fertilization levels. The model was calibrated with a 2012 dataset of growth, phenology, and yield parameters for estimating the genetic coefficients of cultivar TMV-2 and was validated with a 2013 dataset of the same parameters. Simulations of pod yield and other yield parameters using the calibrated model were found to be quite accurate. The model was able to reasonably simulate pod yield and final biomass with low normalized root mean square error (RMSE_n), low absolute root mean square error (RMSE_a) and high coefficient of determination (R^2> 0.7) over a wide range of sowing dates and different phosphorus fertilization levels sensitivity analysis indicated that sowing from the second week of January to the end of February with 30–50 kg P_2O_5 ha^(-1)would give the highest pod yield.
基金This research was financially supported by the Academia Sinica Foundation
文摘This paper discusses the Rb-Sr geochemical behaviour of illites in the sedimentary process, and points out that illites of the lmd and lm types could reach Sr-isotopic equilibrium with its environmental medium during the sedimentary process and initial stage of diagenesis, and illite grains of different sizes have various Rb contents. A new dating method for sedimentary rocks----a dating model of illite grain Rb-Sr isochron----is established, in consideration of the geochemical process of Sr-isotopic homogenization and differentiation in the course of their formation and evolution. In addition, the paper concerns the application of the dating model to the Precambrian unmetamorphosed sedimentary rocks in western Henan Province, which gives satisfactory results coincident with the geological facts.
文摘The method to determine the surface albedo using satellite date hasbeen developed and discussed. The relatons betwam the planetary albedo andsurfoce albedo in clear skies are derived with the help of the radiative transfermodelling. To improve the accuracy of the denved surfoce albedo, theparameter X0, i.e., the ratio of the reflected to the total extinction radiation isintroduced into this model. The influences of the model paramenters on thesurfoce albedo have been analyzed. It is found that the error in the derivedsurfoce albedo due to the paramaters together is less than that caused by oulyone parameter because of the complementarity of the parameters. Test resultsin 22 stations over China have been given using the Geostationary SatelliteGMS. The results are generally agreeable except for the case of snow/ice cover.
文摘地震灾害观测数据多源异构、蕴含知识分散且关联程度低,导致难以高效利用数据进行信息整合和查询,进而提供风险评估、救援决策辅助支持。知识图谱是一种有效的数据关联和融合的手段。首先,基于自顶向下方法梳理地震灾害领域概念,构建地震灾害数据、地质/地理环境、地震灾害事件、地震灾害应急任务、地震灾害模型本体,形成地震灾害本体层;结合自底向上方法构建高质量数据层,通过卷积神经网络对遥感影像进行灾害前后变化识别,实现从影像信息到文本知识的智能结构化转换;融合微调后通用信息抽取框架(universal information extraction,简称UIE)预训练模型对文本数据进行命名实体及关系属性知识抽取,精确率分别为82.04%和70.66%。通过计算词向量语义相似度实现数据融合与统一表达。以2023年12月18日甘肃省临夏州积石山县地震为例,通过本体构建、数据抽取、统一表达形成高质量地震灾害知识图谱,实现地震灾害多源异构地震数据到统一知识表达的转化。基于所构建的地震灾害知识图谱实现了灾害损失、应急链决策支持的查询展示,及结合相关地质数据推理和查询潜在次生灾害。该方法结合深度学习与预训练技术,融合多模态数据,构建了地震灾害知识图谱构建,为快速准确的地震灾害信息查询与次生灾害发生提供辅助支撑。
文摘齐家文化是甘青地区新石器时代晚期至青铜时代早期的文化,是中国最早受欧亚大陆史前文化交流显著影响的重要文化类型,由于缺少对已发表测年数据的系统性研究与评价,对于齐家文化形成年代和发展过程等相关问题的研究仍存在许多不足。本文收集整理了已发表的37个遗址的137个齐家文化^(14)C测年数据,并选择可靠测年的71个植物残体(作物种子)和骨骼测年数据,利用贝叶斯方法建立年代模型,由此推测齐家文化形成时代为4200—3400 cal a B.P.(指距1950年的日历年,即2250―1450aB.C.),结束年龄比过去认为的3500 a B.P.更晚,并发现已发表的炭屑测年存在200~300 a的“老碳”效应。依据新建立的齐家文化年代模型,齐家文化在4200 cal a B.P.首先在甘肃东部的泾河-渭河上游发展,后向西扩散到黄土高原西部、青藏高原东北边缘和河西走廊东段,随后在3800 a B.P.之后重心收缩到青藏高原东北缘地区,推测齐家文化晚期受跨大陆交流影响导致的齐家文化内部分化和转型是齐家文化走向衰亡的原因。
