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Search Results: 1 - 10 of 115531 matches for " 郭建坡 "
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恒星在形成过程中释放的引力势能
Gravitational Potential Energy Releasing during the Star Formation
 [PDF]

, 林灵, 白春燕
Astronomy and Astrophysics (AAS) , 2015, DOI: 10.12677/AAS.2015.33005
Abstract:
在计算恒星的引力势能以及形成时标的时候,如果采用均匀球模型,会产生较大误差,因为恒星的密度从中心到表面差异非常大。我们采用Eggleton’s恒星演化程序构建了6种不同金属丰度、30种不同质量的零龄主序恒星模型。Eggleton’s恒星演化程序把恒星分成199个均匀同心壳层。我们推导出了恒星每个壳层的引力势能的精确表达式,精确地算出了恒星的引力势能;进而算出了恒星的引力势能系数和形成时标。我们算出的恒星引力势能系数和形成时标与前人的数据是一致的,我们的计算结果与年轻星团的观测图景也是相符合的。
There is a great difference for stellar density from center to surface. If we think stellar density is homogeneous, it will get obvious error when we calculate stellar gravitational potential energy and star formation timescale. Using Eggleton’s code, we construct a series of zero age main sequence models of stars, with 6 metallicities and 30 masses. In Eggleton’s code, a star is divided into 199 homogeneous shells, with the same center. We get the accurate formula of gravitational potential energy for every shell, and calculate the potential energy for the whole star. Furthermore, we calculate the coefficient of stellar gravitational potential energy and star formation timescale. Our results are coincident with previous data and observation of young cluster.
α增丰对极端水平分支星的影响
The Effects of α-Enhancement on the Evolution of EHB Stars
 [PDF]

, 叶根, 熊作朝
Astronomy and Astrophysics (AAS) , 2016, DOI: 10.12677/AAS.2016.41003
Abstract:
金属元素分析表明:在银河系的球状星团和椭圆星系中,普遍存在α增丰现象。极端水平分支星是一种处在氦燃烧阶段的天体,它们具有非常薄的氢包层。我们用Eggleton’s恒星演化程序,研究了α增丰对极端水平分支星的影响。我们计算了不同金属丰度、不同核心质量和不同包层质量的极端水平分支星的演化;金属丰度取0.001、0.004、0.02和0.04,核心质量取0.400、0.450、0.475、0.500和0.550 M☉,包层质量取0.001、0.005、0.010、0.015和0.020 M☉。通过研究发现,α增丰可以使极端水平分支星的有效温度升高,表面重力加速度和光度增大,演化寿命变短。金属丰度越大,α增丰效应越明显;包层越厚,α增丰效应越明显。
Analyses of metal elements have shown α-enhanced phenomenon in some globular clusters of the Milky Way and in some elliptical galaxies. Extreme horizontal branch (EHB) stars are helium burning objects with especially thin hydrogen envelopes. We study the effects of α-enhancement on the evolution of EHB stars, using Eggleton’s code. We calculate the evolution of EHB stars with metallicities 0.001, 0.004, 0.02 and 0.04, core masses 0.400, 0.450, 0.475, 0.500 and 0.550 M☉, and envelope masses 0.001, 0.005, 0.010, 0.015 and 0.020 M☉. It is found that α-enhancement can raise effective temperatures, surface gravities and luminosities, and shorten evolutionary lifetime for EHB stars. The higher values their metallicities are, the more obvious the α-enhanced effects are; and the thicker their envelopes are, the more obvious the α-enhanced effects are.
太阳系的角动量
The Angular Momentum of the Solar System
 [PDF]

仓荣琴, , 胡娟秀, 何超琼
Astronomy and Astrophysics (AAS) , 2016, DOI: 10.12677/AAS.2016.42004
Abstract:
太阳系的角动量对于太阳系的形成和演化来说是一个非常重要的物理量。以前人们在计算太阳系的角动量时,通常只考虑太阳的自转角动量和八大行星的轨道角动量;这种做法现在看起来有些狭隘和保守。我们用Eggleton’s恒星演化程序来计算太阳的转动惯量,进而求出太阳的自转角动量为1.8838 × 1041 kg?m2?s?1。除了太阳的自转角动量和八大行星的轨道角动量,我们还考虑了小行星带、柯伊伯带、奥尔特云、第九大行星和太阳伴星的轨道角动量,算出整个太阳系的角动量为3.3212 × 1045 kg?m2?s?1
The angular momentum of the Solar System is a very important physical quantity to the formation and evolution of the Solar System. Previously, the spin angular momentum of the Sun and the orbital angular momentum of the Eight Giant Planets were only taken into consideration, when researchers calculated the angular momentum of the Solar System. Nowadays, it seems narrow and conservative. Using Eggleton’s code, we calculate the rotational inertia of the Sun. Furthermore, we obtain that the spin angular momentum of the Sun is 1.8838 × 1041 kg?m2?s?1. Besides the spin angular momentum of the Sun and the orbital angular momentum of the Eight Giant Planets, we also account for the orbital angular momentum of the Asteroid Belt, the Kuiper Belt, the Oort Cloud, the Ninth Giant Planet and the Solar Companion. We obtain that the angular momentum of the whole Solar System is 3.3212 × 1045 kg?m2?s?1.
小行星撞击地球的能量
The Energy of an Asteroid Hitting the Earth
 [PDF]

何超琼, , 仓荣琴, 胡娟秀
Astronomy and Astrophysics (AAS) , 2016, DOI: 10.12677/AAS.2016.43006
Abstract:
小行星撞击地球可能导致了6500万年前恐龙灭绝。本文的研究目标是:在质量一定的情况下,小行星的远日点距离和近日点距离的差异,究竟会在多大程度上影响小行星撞击地球的能量。我们采用的小行星的远日点距离分别为1.90、2.15、2.65、3.25、3.50、3.95和5.2075AU,近日点距离分别为1.0009、0.95、0.90、0.85、0.80、0.75、0.70、0.65、0.60、0.55和0.50AU。我们的计算结果表明:小行星的远日点距离越大,撞击地球的能量越大;小行星的近日点距离越小,撞击地球的能量越大;小行星撞击地球的最小动能为1.0725 \"\"1023 J,最大动能为5.8280\"\"1023 J。
An asteroid hitting the Earth may cause the extinction of dinosaurs, 65 million years ago. The re-search aim of this paper is how the energy of the asteroid hitting the Earth can be depending on the chosen of the aphelion distance and the perihelion distance, while the mass of the asteroid is fixed. The adopted aphelion distance of the asteroid is 1.90, 2.15, 2.65, 3.25, 3.95 and 5.2075 AU, respectively. The adopted perihelion distance of the asteroid is 1.0009, 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55 and 0.50 AU, respectively. Our calculated results show that the larger the aphelion distance of the asteroid is, the larger the energy of its hitting the Earth is; the smaller the perihelion distance of the asteroid is, the larger the energy of its hitting the Earth is; the minimum kinetic energy of the asteroid hitting the earth is 1.0725\"\"1023 J, and the maximum kinetic energy is 5.8280\"\"1023 J.
开普勒-47双星系统的宜居带
The Habitable Zone of Kepler-47 Binary System
 [PDF]

胡娟秀, , 何超琼, 仓荣琴
Astronomy and Astrophysics (AAS) , 2016, DOI: 10.12677/AAS.2016.43007
Abstract:
一颗系外行星上如果存在生命,它需要位于其寄主恒星的宜居带中。本文考虑了恒星有效温度对宜居带的影响,给出了双星宜居带的内、外边界的距离满足的方程。我们用数值法求出了开普勒-47双星系统的宜居带,其内、外边界的平均半径分别为0.77761和1.55287AU。开普勒-47内行星距离双星比较近,不在宜居带中。开普勒-47外行星围绕双星公转的轨道可能是一个椭率为0.411的椭圆,它的远日点处在宜居带中,而近日点不在宜居带中。在一个公转周期内,它有237.837至239.056天的时间处在宜居带中,而有64.102至65.321天的时间不在宜居带中。
Provided that there are lives living on an exoplanet, it must be located in the habitable zone of its host star. Considering the effects of stellar effective temperature on habitable zone, we give the distance equations on the inside and the outside boundary of binary’s habitable zone. Using the numerical methods, we obtain the habitable zone of the Kepler-47 binary system. The average distances on the inside and the outside boundary are 0.77761 and 1.55287 AU, respectively. The distance of the Kepler-47 inner planet is too small to be within the habitable zone. The orbit of the Kepler-47 outer planet may be an ellipse. Its eccentricity is 0.411; its aphelion is within the habitable zone, and its perihelion is not within the habitable zone. In an orbital period, there are 237.837 - 239.056 days that the Kepler-47 outer planet is within the habitable zone and there are 64.102 - 65.321 days that it is not within the habitable zone.
模块化多电平换流器子模块拓扑仿真分析
,赵成勇,
电力系统自动化 , 2015, DOI: 10.7500/AEPS20130821005
Abstract: 新型模块化多电平换流器(MMC)在直流输电和电能变换领域得到了广泛的研究与应用。但是,由于子模块采用了半桥型拓扑,在直流侧线路故障时,MMC不具有直流故障自清除能力。文中在不改变现有MMC调制和均压策略的前提下,利用续流二极管反向阻断特性和桥臂模块电容充电效应,设计了改进复合拓扑结构,解决了半桥拓扑中电容单向充电问题。通过分析闭锁时储能电容不同充电路径下交流电压与桥臂等效直流电压关系,定义了反映子模块故障抑制能力的电流抑制系数。根据系统启动过程中不控整流阶段电容电压的不同,设计了自励启动方法。仿真结果验证了启动方法和复合拓扑对直流侧故障电流抑制的有效性。
欠电位沉积研究进展
,,李文,胡舸,张胜涛
化学进展 , 2013, DOI: 10.7536/PC130148
Abstract: 欠电位沉积(underpotentialdeposition,UPD)是指一种金属可在比其热力学可逆电位正的电位下沉积在另一基体上的现象,是一个与电极/溶液结构密切相关的重要的电化学现象。从广义上讲,定义中的沉积元素与基体不仅仅局限于金属元素,还包括非金属元素、纳米粒子等其它物质。由于单原子厚度的异种金属能显著改变界面附近的电势分布和影响溶剂分子的取向,并改变基底金属表面的吸附行为和反应能力,使得UPD在电催化和金属与合金电沉积研究中颇受重视。迄今为止,已报道了大量UPD实验现象。本文在现有文献基础上,总结了UPD的若干理论模型及其行为特征,着重探讨了衬底、离子吸附、温度等因素对UPD过程的影响作用,介绍了UPD应用的主要成功实例,并对其研究前景提出了展望。
Phase Shift and Penetration Depth of Metal Mirror in Microcavity Structure
微腔器件中金属镜反射相移与穿透深度研究

ZHANG Yong,SU Jian-po,GUO Mao-tian,MA Feng-ying,
张勇
,,茂田,马凤英

光子学报 , 2009,
Abstract: In order to solve the error result of the penetration depth that was caused by confused sign convention for the phase factor of electromagnetic sinusoidal waves,inconsistency was found in the expression of the phase shift and the relation of the phase shift and the penetration depth .The results on the phase shift and penetration depth of metal mirror in microcavities were reported.A series of λ/2 cavities with the symmetrical structure of Glass/Ag/LiF/Ag was made by changing the thickness of Ag film.The penetration depths at different thickness of Ag film were obtained from the transmittance peaks of the cavities.Phase shift upon reflection at LiF-Ag interface was calculated based on the measured optical constants.The formulation between phase shift and penetration depth was proved by the experimental results,which are in good agreement with the theoretical calculations.
A Study of High-resolution Sequence Stratigraphic Characteristics and Coal Accumulation in Upper Paleozoic Strata of the Shanxian Coalfield
单县矿区高分辨率层序地层及成煤作用研究

吕大炜,梁吉,李增学,王薇,吴立荣,张义江,,宋洪柱
地球学报 , 2008,
Abstract: Based on the principle of high-resolution sequence stratigraphy and an integrated analysis of the bore core and well logging, the authors divided different base level cycles of Upper Paleozoic strata in the study area. Four types of base level cycles were recognized: short, intermediate, long and extremely long. Through a comparative analysis, a high-resolution sequence framework was established. Researches show that the most favorable coal accumulation of the study area occurred at the special positions of the base level cycles (A/S close to 1), i.e., at the half level of the descending long base level and the late stage of the descending half level of the middle base level. According to the basin filling and the superimposition of different classes of base levels, the coal accumulation of the study area can be divided into early accumulation and late accumulation. The base level change of both accumulations and the course of basin filling evolution are analyzed in this paper.
单县矿区高分辨率层序地层及成煤作用研究
吕大炜,梁吉,李增学,王薇,吴立荣,张义江,,宋洪柱
地球学报 , 2008, DOI: 10.3975/cagsb.2008.05.14
Abstract: 运用高分辨率层序地层原理,通过岩心、测井资料的综合分析,对研究区上古生界进行了不同周期地层基准面旋回研究,识别出短期、中期、长期及超长期4种规模的地层旋回。通过对比分析,建立了该区高分辨率层序地层格架。研究表明,研究区成煤作用出现于基准面旋回的特殊位置(A/S接近于1),当叠置在长期基准面旋回下降半旋回和中期基准面旋回下降半旋回晚期是成煤的最有利时期。根据盆地充填演化和不同级次基准面旋回叠加可以将研究区成煤作用分为早期成煤作用和晚期成煤作用,依次分析了不同时期成煤作用的地层基准面变化和盆地沉积充填演化的过程。
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