hay 和 straw 都是“草”但它们之间是有区别的。hay 是专门为牲口种的饲料,straw 是指一般的稻草。美国建国初期还是一个以农业为主的国家。当时农民在夏天收割已经长高了的草,晒干入库,作为冬天喂牲口的饲料。及时做好这项工作是很重...hay 和 straw 都是“草”但它们之间是有区别的。hay 是专门为牲口种的饲料,straw 是指一般的稻草。美国建国初期还是一个以农业为主的国家。当时农民在夏天收割已经长高了的草,晒干入库,作为冬天喂牲口的饲料。及时做好这项工作是很重要的,因为干草淋湿了,就会发霉。俗语 to make hay while the sun shines 即源于此。美国人经常把这个俗语缩减成 to make hay。现在 to make hay 与准备饲料没有多大关系了,它的意思是“抓住时机,尽量从中获利”。例如:The smart thing is to buy as much stock as you can afford,if you want展开更多
The front-row shading reduction coefficient is a key parameter used to calculate the system efficiency of a photovoltaic(PV)power station.Based on the Hay anisotropic sky scattering model,the variation rule of solar r...The front-row shading reduction coefficient is a key parameter used to calculate the system efficiency of a photovoltaic(PV)power station.Based on the Hay anisotropic sky scattering model,the variation rule of solar radiation intensity on the surface of the PV array during the shaded period is simulated,combined with the voltage-current characteristics of the PV modules,and the shadow occlusion operating mode of the PV array is modeled.A method for calculating the loss coefficient of front shadow occlusion based on the division of the PV cell string unit and Hay anisotropic sky scattering model is proposed.This algorithm can accurately evaluate the degree of influence of the PV array layout,wiring mode,array spacing,PV module specifications,and solar radiation on PV power station system efficiency.It provides a basis for optimizing the PV array layout,reducing system loss,and improving PV system efficiency.展开更多
美国总统图书馆(Presidential Libraries in the U.S)内存放着以往美国总统的报纸(papers),文件(documents)及私人材料(personal materials)。富兰克林·罗斯福(Franklin Roosevelt)建立了由政府管理的第一个总统图书馆。罗斯福希...美国总统图书馆(Presidential Libraries in the U.S)内存放着以往美国总统的报纸(papers),文件(documents)及私人材料(personal materials)。富兰克林·罗斯福(Franklin Roosevelt)建立了由政府管理的第一个总统图书馆。罗斯福希望把弘人文件集中放在一个专门的地方,便自己设计了一幢楼。这幢楼建在纽约—离他的官邸不远的海德公园(Hyde park)。他把这个图书馆交给了国家,由联邦局的国家档案局负责管理。富兰克林·罗斯福图书馆(the Franklin Roosevelt Library)展开更多
针对蚁群聚类算法在聚类结果中出现部分数据划分不够准确的问题,提出蚁群聚类改进算法。对已有蚁群聚类算法的结果簇做调整,从而得到更好的聚类结果。使用KDD Cup 1999入侵检测数据集所作的实验结果表明,聚类效果改进明显,入侵检测率有...针对蚁群聚类算法在聚类结果中出现部分数据划分不够准确的问题,提出蚁群聚类改进算法。对已有蚁群聚类算法的结果簇做调整,从而得到更好的聚类结果。使用KDD Cup 1999入侵检测数据集所作的实验结果表明,聚类效果改进明显,入侵检测率有所提高。展开更多
文摘hay 和 straw 都是“草”但它们之间是有区别的。hay 是专门为牲口种的饲料,straw 是指一般的稻草。美国建国初期还是一个以农业为主的国家。当时农民在夏天收割已经长高了的草,晒干入库,作为冬天喂牲口的饲料。及时做好这项工作是很重要的,因为干草淋湿了,就会发霉。俗语 to make hay while the sun shines 即源于此。美国人经常把这个俗语缩减成 to make hay。现在 to make hay 与准备饲料没有多大关系了,它的意思是“抓住时机,尽量从中获利”。例如:The smart thing is to buy as much stock as you can afford,if you want
基金This work was supported by the Global Energy Interconnection Group Limited Science&Technology Project(Project No.:SGGEIG00JYJS1900046).
文摘The front-row shading reduction coefficient is a key parameter used to calculate the system efficiency of a photovoltaic(PV)power station.Based on the Hay anisotropic sky scattering model,the variation rule of solar radiation intensity on the surface of the PV array during the shaded period is simulated,combined with the voltage-current characteristics of the PV modules,and the shadow occlusion operating mode of the PV array is modeled.A method for calculating the loss coefficient of front shadow occlusion based on the division of the PV cell string unit and Hay anisotropic sky scattering model is proposed.This algorithm can accurately evaluate the degree of influence of the PV array layout,wiring mode,array spacing,PV module specifications,and solar radiation on PV power station system efficiency.It provides a basis for optimizing the PV array layout,reducing system loss,and improving PV system efficiency.
文摘美国总统图书馆(Presidential Libraries in the U.S)内存放着以往美国总统的报纸(papers),文件(documents)及私人材料(personal materials)。富兰克林·罗斯福(Franklin Roosevelt)建立了由政府管理的第一个总统图书馆。罗斯福希望把弘人文件集中放在一个专门的地方,便自己设计了一幢楼。这幢楼建在纽约—离他的官邸不远的海德公园(Hyde park)。他把这个图书馆交给了国家,由联邦局的国家档案局负责管理。富兰克林·罗斯福图书馆(the Franklin Roosevelt Library)
