遥感数据呈现大数据特征并广泛应用于资源调查、环境监测、灾害评估等领域,但其潜在的应用价值还没有被充分挖掘出来。遥感数据工程的建立将有助于遥感数据的智能分析和信息挖掘。即得即用(Ready To Use,RTU)产品具有辐射归一化、几何...遥感数据呈现大数据特征并广泛应用于资源调查、环境监测、灾害评估等领域,但其潜在的应用价值还没有被充分挖掘出来。遥感数据工程的建立将有助于遥感数据的智能分析和信息挖掘。即得即用(Ready To Use,RTU)产品具有辐射归一化、几何标准化、剖分网格化等特点,可直接用于后续的分析应用。RTU产品的研究开发是遥感数据工程的重要内容之一。以卫星遥感数据为基础,介绍了遥感数据RTU产品的定义与组成、RTU产品的标准规范、RTU地理格网剖分等,为用户使用RTU产品提供参考。多源卫星遥感数据RTU产品将持续不断地通过CASEarth DataBank系统(databank.casearth.cn)向管理工作者、行业应用者、科学研究者以及其他公众提供共享服务。展开更多
By using some elementary inequalities, authors in this paper makes further improvement for estimating the heights of Bézier curve and rational Bézier curve. And the termination criterion for subdivision of t...By using some elementary inequalities, authors in this paper makes further improvement for estimating the heights of Bézier curve and rational Bézier curve. And the termination criterion for subdivision of the rational Bézier curve is also improved. The conclusion of the extreme value problem is thus further confirmed.展开更多
This study investigated the heat transfer and flow characteristics of one kind of swirlgenerator in a circular heat exchanger tube through a numericalsimulation. The swirlflow induced by this type of swirlgenerator ca...This study investigated the heat transfer and flow characteristics of one kind of swirlgenerator in a circular heat exchanger tube through a numericalsimulation. The swirlflow induced by this type of swirlgenerator can obtain a high heat transfer rate with minimalpressure drop penalty. The simulations were carried out to understand the physicalbehavior of this kind of mesoscale heat enhancement component. By visualizing the heat transfer and flow characteristics, it is found that the swirlflow is induced by swirlgenerator in the circular tube couples with the impinging jet effect. After passing through the swirlgenerator, the localfriction factor of liquid can quickly return to lower levelmore quickly, while the localNusselt number maintains higher values for a distance; thus, the evaluation criterion of localperformance is improved. Single-factor optimization is used for three geometric parameters, i.e., the angle of swirlgenerator(25o, 45o, and 60o), the length of swirlgenerator(0.005, 0.01, and 0.02 m), and the center rod radius(1, 2, and 3 mm). The optimum parameters of the swirlgenerator for laminar flow of air in a circular tube are obtained, which should be 60o, 0.005 m, and 3 mm, respectively.展开更多
Several models in noncommutative geometry (NCG) with mild changes to the standard model are introduced to discuss the neutrino mass problem. We use two constraints, Poincaré duality and gauge anomaly free, to dis...Several models in noncommutative geometry (NCG) with mild changes to the standard model are introduced to discuss the neutrino mass problem. We use two constraints, Poincaré duality and gauge anomaly free, to discuss the possibility of containing right-handed neutrinos in them. Our work shows that no model in this paper, with each generation containing a right-handed neutrino, can satisfy these two constraints at the same time. So, to consist with neutrino oscillation experiment results, maybe fundamental changes to the present version of NCG are usually needed to include Dirac massive neutrinos.展开更多
文摘遥感数据呈现大数据特征并广泛应用于资源调查、环境监测、灾害评估等领域,但其潜在的应用价值还没有被充分挖掘出来。遥感数据工程的建立将有助于遥感数据的智能分析和信息挖掘。即得即用(Ready To Use,RTU)产品具有辐射归一化、几何标准化、剖分网格化等特点,可直接用于后续的分析应用。RTU产品的研究开发是遥感数据工程的重要内容之一。以卫星遥感数据为基础,介绍了遥感数据RTU产品的定义与组成、RTU产品的标准规范、RTU地理格网剖分等,为用户使用RTU产品提供参考。多源卫星遥感数据RTU产品将持续不断地通过CASEarth DataBank系统(databank.casearth.cn)向管理工作者、行业应用者、科学研究者以及其他公众提供共享服务。
文摘By using some elementary inequalities, authors in this paper makes further improvement for estimating the heights of Bézier curve and rational Bézier curve. And the termination criterion for subdivision of the rational Bézier curve is also improved. The conclusion of the extreme value problem is thus further confirmed.
基金supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China (No. 2016YFC0400406)
文摘This study investigated the heat transfer and flow characteristics of one kind of swirlgenerator in a circular heat exchanger tube through a numericalsimulation. The swirlflow induced by this type of swirlgenerator can obtain a high heat transfer rate with minimalpressure drop penalty. The simulations were carried out to understand the physicalbehavior of this kind of mesoscale heat enhancement component. By visualizing the heat transfer and flow characteristics, it is found that the swirlflow is induced by swirlgenerator in the circular tube couples with the impinging jet effect. After passing through the swirlgenerator, the localfriction factor of liquid can quickly return to lower levelmore quickly, while the localNusselt number maintains higher values for a distance; thus, the evaluation criterion of localperformance is improved. Single-factor optimization is used for three geometric parameters, i.e., the angle of swirlgenerator(25o, 45o, and 60o), the length of swirlgenerator(0.005, 0.01, and 0.02 m), and the center rod radius(1, 2, and 3 mm). The optimum parameters of the swirlgenerator for laminar flow of air in a circular tube are obtained, which should be 60o, 0.005 m, and 3 mm, respectively.
文摘Several models in noncommutative geometry (NCG) with mild changes to the standard model are introduced to discuss the neutrino mass problem. We use two constraints, Poincaré duality and gauge anomaly free, to discuss the possibility of containing right-handed neutrinos in them. Our work shows that no model in this paper, with each generation containing a right-handed neutrino, can satisfy these two constraints at the same time. So, to consist with neutrino oscillation experiment results, maybe fundamental changes to the present version of NCG are usually needed to include Dirac massive neutrinos.
