In Taiwan’s history, rice and sugarcane," the two main e-conomical foundation stones" of Taiwan, were well knownin the world. Taiwan was one of the main rice-productionareas in China, which had always been ...In Taiwan’s history, rice and sugarcane," the two main e-conomical foundation stones" of Taiwan, were well knownin the world. Taiwan was one of the main rice-productionareas in China, which had always been called "rice ware-house". In this article, the author would do a preliminaryresearch on the primitive rice cultivation pattern from im-memorial time to the earlier stage of Qing Dynasty ( 1616 -展开更多
There are many water-filling factors in Xiaotun Coal Mine, such as effective precipitation, goaf water, mining-induced fissure zone, surface water system, aquifers and tectonics. For different mining levels, the relat...There are many water-filling factors in Xiaotun Coal Mine, such as effective precipitation, goaf water, mining-induced fissure zone, surface water system, aquifers and tectonics. For different mining levels, the relative importance of these factors is different, and the water-filling condition is changed accordingly. So it is urgent to make it clear for mining. To ensure the safety of mining, we build a system of preventing mine water-filling using detailed AHP (analytical hierarchy process) calculation. This system is based on the analysis of mine water-filling factors in order to define the relative importance of the factors. Decision-makers use it as a strong scientific basis for Xiaotun Coal Mine.The method offered in this paper has been proved to be very applicable.展开更多
为厘清大豆氮肥管理领域的研究态势、发展现状和发展趋势,基于中国知网数据库和Web of Science核心数据库检索1995—2024年中国大豆氮肥管理相关文献,经筛选整理,共得到525篇中文文献和179篇英文文献,利用CiteSpace软件对文献进行可视...为厘清大豆氮肥管理领域的研究态势、发展现状和发展趋势,基于中国知网数据库和Web of Science核心数据库检索1995—2024年中国大豆氮肥管理相关文献,经筛选整理,共得到525篇中文文献和179篇英文文献,利用CiteSpace软件对文献进行可视化分析。结果表明:1)1995—2024年,我国大豆氮肥管理研究领域发文量总体呈波动上升趋势,2003年后增速显著,发文量受国家出台的相关政策影响显著。2)我国对大豆氮肥管理的研究视角逐渐从传统农业科学转向与植物学、生态学和经济学等多学科交叉融合,极大拓宽了研究方向。3)我国大豆氮肥管理的研究热点聚焦于土壤根瘤菌及根瘤固氮机理、根际微生物群落调控作用、环境效益评估和种植体系氮素效率利用等方面,且英文文献更关注大豆间作系统的经济效益与生态效益。4)中国大豆氮肥管理的研究作者以杨文钰和马春梅为核心,研究机构主要集中在我国东北地区和西南地区,以东北农业大学和四川农业大学为中心,呈“区域聚集-全局分散”特征,跨区域合作明显不足,未来亟待深化多学科、多地域协同研究。本研究可为科研人员提供中国大豆氮肥管理领域发展全景视角,为农业调控政策制定提供理论依据,为大豆养分管理研究提供思路和方向。展开更多
Purpose-The design goal for the tracking interval of high-speed railway trains in China is 3 min,but it is difficult to achieve,and it is widely believed that it is mainly limited by the tracking interval of train arr...Purpose-The design goal for the tracking interval of high-speed railway trains in China is 3 min,but it is difficult to achieve,and it is widely believed that it is mainly limited by the tracking interval of train arrivals.If the train arrival tracking interval can be compressed,it will be beneficial for China's high-speed railway to achieve a 3-min train tracking interval.The goal of this article is to study how to compress the train arrival tracking interval.Design/methodologylapproach-By simulating the process of dense train groups arriving at the station and stopping,the headway between train arrivals at the station was calculated,and the pattern of train arrival headway was obtained,changing the traditional understanding that the train arrival headway is considered the main factor limiting the headway of trains.Findings-When the running speed of trains is high,the headway between trains is short,the length of the station approach throat area is considerable and frequent train arrivals at the station,the arrival headway for the first group or several groups of trains will exceed the headway,but the subsequent sets of trains will havea headway equal to the arrival headway.This convergence characteristic is obtained by appropriately increasing the running time.Originality/value-According to this pattern,there is no need to overly emphasize the impact of train arrival headway on the headway.This plays an important role in compressing train headway and improving high-speedrailwaycapacity.展开更多
文摘In Taiwan’s history, rice and sugarcane," the two main e-conomical foundation stones" of Taiwan, were well knownin the world. Taiwan was one of the main rice-productionareas in China, which had always been called "rice ware-house". In this article, the author would do a preliminaryresearch on the primitive rice cultivation pattern from im-memorial time to the earlier stage of Qing Dynasty ( 1616 -
文摘There are many water-filling factors in Xiaotun Coal Mine, such as effective precipitation, goaf water, mining-induced fissure zone, surface water system, aquifers and tectonics. For different mining levels, the relative importance of these factors is different, and the water-filling condition is changed accordingly. So it is urgent to make it clear for mining. To ensure the safety of mining, we build a system of preventing mine water-filling using detailed AHP (analytical hierarchy process) calculation. This system is based on the analysis of mine water-filling factors in order to define the relative importance of the factors. Decision-makers use it as a strong scientific basis for Xiaotun Coal Mine.The method offered in this paper has been proved to be very applicable.
文摘为厘清大豆氮肥管理领域的研究态势、发展现状和发展趋势,基于中国知网数据库和Web of Science核心数据库检索1995—2024年中国大豆氮肥管理相关文献,经筛选整理,共得到525篇中文文献和179篇英文文献,利用CiteSpace软件对文献进行可视化分析。结果表明:1)1995—2024年,我国大豆氮肥管理研究领域发文量总体呈波动上升趋势,2003年后增速显著,发文量受国家出台的相关政策影响显著。2)我国对大豆氮肥管理的研究视角逐渐从传统农业科学转向与植物学、生态学和经济学等多学科交叉融合,极大拓宽了研究方向。3)我国大豆氮肥管理的研究热点聚焦于土壤根瘤菌及根瘤固氮机理、根际微生物群落调控作用、环境效益评估和种植体系氮素效率利用等方面,且英文文献更关注大豆间作系统的经济效益与生态效益。4)中国大豆氮肥管理的研究作者以杨文钰和马春梅为核心,研究机构主要集中在我国东北地区和西南地区,以东北农业大学和四川农业大学为中心,呈“区域聚集-全局分散”特征,跨区域合作明显不足,未来亟待深化多学科、多地域协同研究。本研究可为科研人员提供中国大豆氮肥管理领域发展全景视角,为农业调控政策制定提供理论依据,为大豆养分管理研究提供思路和方向。
基金State Railway Corporation of China Limited under the Science and Technology Research and Development Programme(2021X007)China Academy of Railway Research(2021YJ012)+1 种基金National Natural Science Foundation of China(52302417)Natural Science Foundation of Sichuan Province of China(2023NSFSC0906).
文摘Purpose-The design goal for the tracking interval of high-speed railway trains in China is 3 min,but it is difficult to achieve,and it is widely believed that it is mainly limited by the tracking interval of train arrivals.If the train arrival tracking interval can be compressed,it will be beneficial for China's high-speed railway to achieve a 3-min train tracking interval.The goal of this article is to study how to compress the train arrival tracking interval.Design/methodologylapproach-By simulating the process of dense train groups arriving at the station and stopping,the headway between train arrivals at the station was calculated,and the pattern of train arrival headway was obtained,changing the traditional understanding that the train arrival headway is considered the main factor limiting the headway of trains.Findings-When the running speed of trains is high,the headway between trains is short,the length of the station approach throat area is considerable and frequent train arrivals at the station,the arrival headway for the first group or several groups of trains will exceed the headway,but the subsequent sets of trains will havea headway equal to the arrival headway.This convergence characteristic is obtained by appropriately increasing the running time.Originality/value-According to this pattern,there is no need to overly emphasize the impact of train arrival headway on the headway.This plays an important role in compressing train headway and improving high-speedrailwaycapacity.
