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81.
Masayoshi Sekiguchi 《Celestial Mechanics and Dynamical Astronomy》2004,90(3-4):355-360
The bifurcation of central configuration in the Newtonian N-body problem for any odd number N ≥ 7 is shown. We study a special
case where 2n particles of mass m on the vertices of two different coplanar and concentric regular n-gons (rosette configuration)
and an additional particle of mass m0 at the center are governed by the gravitational law he 2n+1 body problem. This system is of two degrees of freedom and permits
only one mass parameter μ =m
0/m. This parameter μ controls the bifurcation. If n≥ 3, namely any odd N ≥ 7, then the number of central configurations is three
when μ ≥ μ
c
, and one when μ ≥ μ
c
. By combining the results of the preceding studies and our main theorem, explicit examples of bifurcating central configuration
are obtained for N ≤ 13, for any odd N ∈ [15,943], and for any N ≥ 945. 相似文献
82.
Akiko Sakai Koji Fujita Chiyuki Narama Jumpei Kubota Masayoshi Nakawo Tandong Yao 《水文研究》2010,24(19):2798-2806
Discharge was calculated from a mountainous area, including discharge from glaciers, in the Qilian Shan (Qilian Mountains) of northwest China. The studied Yingluoxia basin is 9983 km2 in area, with glaciers making up 0·3% of the basin. The calculation method was based on the heat balance, requiring only daily temperature and precipitation. Calculated annual discharge from the basin corresponded well with the observed data. Calculated annual discharge from glaciers was 3·6% of the total discharge from the basin. The temporal trend of the calculated equilibrium line altitude (ELA) at the July 1st Glacier (western side of the Yingluoxia basin) was similar to that of the observed ELA. The calculated annual mass balance of glaciers within the Yingluoxia basin has a larger negative value than the other glaciers in China, as the ratio of accumulation area to the total glacier area in the Yingluoxia basin is much lower than in neighbouring basins to the west. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
83.
84.
Mutsuo Inoue Yusuke Nakano Yoko Kiyomoto Hisaki Kofuji Yasunori Hamajima Masayoshi Yamamoto 《Journal of Oceanography》2010,66(3):425-428
A total of 21 surface water samples were collected on the east side of the East China Sea (ECS) (3 sites) and at the Tsushima
Strait (1 site), and 226Ra and 228Ra activities were measured using low-background γ-spectrometry. The 228Ra/226Ra ratios among the samples exhibited notable seasonal variation (228Ra/226Ra = 0.2–2.6) accompanying changes of salinity (31.7–34.7). Seasonal water circulation within the ECS is hypothesized to cause
the change by altering the mixing ratio of 228Ra-rich continental shelf water and 228Ra-poor Kuroshio water. 相似文献
85.
Variation of precipitation δ18O in Langtang Valley Himalayas 总被引:1,自引:0,他引:1
The variation of the δ18O in precipitation and the relationship with precipitation amount at Kyangjin Base House and Yala Glacier Camp in Langtang
Valley, Nepal Himalayas were analyzed. The variations of the δ18O with precipitation had great scatter, and the correlations between the δ18O and precipitation changed with time on the synoptic scale. On the seasonal scale, there was marked amount effect at Kyangjin
Base House. However, the δ18O-precipitation gradient was smaller than that on the synoptic scale. Because of the maintenance of the basic equilibrium
between stable isotopic compositions in atmospheric vapor and precipitation, the evaporation enrichment was light during the
rainy season. Therefore, the variation of stable isotopic compositions in precipitation was independent on the sampling intervals.
Simulations show that the rainfall in Langtang Valley was not the outcome of the initial condensation of ocean vapor that
originated from low latitudes. The stable isotopic compositions in precipitation were greatly depleted due to the strong rainout
of the vapor from oceans as the vapor was raised over the Himalayas. 相似文献
86.
Peng Pan Hiroshi Tomofuji Tao Wang Masayoshi Nakashima Makoto Ohsaki Khalid M. Mosalam 《地震工程与结构动力学》2006,35(7):867-890
A new Internet online hybrid test system, designated the ‘peer‐to‐peer (P2P) Internet online hybrid test system’, is proposed. In the system, the simulated structure is divided into multiple substructures, and each substructure is analysed numerically or tested physically in parallel at geographically distributed locations. The equations of motion are not formulated for the entire structure but for each substructure separately. Substructures are treated as highly independent systems, and only standard I/O, i.e. displacements and forces at the boundaries, are used as interfaces. A ‘Coordinator’ equipped with an iterative algorithm based on quasi‐Newton iterations is developed to achieve compatibility and equilibrium at boundaries. A test procedure, featuring two rounds of quasi‐Newton iterations and using assumed elastic stiffness, is adopted to avoid iteration for the substructure being tested physically. A fast and stable solution using a socket mechanism is developed for data exchange over the Internet. Demonstration tests applied to a base‐isolated structure was conducted, and the results are compared with an online hybrid test using the conventional test method. The results obtained from the P2P Internet hybrid test match very closely those obtained from the conventional tests. Investigations are also carried out on time consumption and control accuracy. The results show that the Internet data exchange solution using the socket mechanism is fast, and tests were completed successfully under the constructed Internet online hybrid test environment. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
87.
文中介绍的数学模型考虑了混合云中液、固相共存时以及冰面过饱和环境下稳定同位素的动力分馏效应.利用该数学模型,模拟不同冷却条件下稳定同位素的温度效应.在相同的湿度条件下,湿绝热冷却过程中δ18O随温度的变化率小于等压冷却过程.冰面过饱和比S;的增大意味着动力分馏效应的增大.与平衡态过程相比,它的作用使得稳定同位素的综合分馏系数减小,从而使得降水中δ18O随温度的变化趋缓.模拟结果显示,湿绝热冷却过程中大气水线(MWLδD=bδ18O+d)的梯度项b和常数项d均大于等压冷却过程.不同的冰面过饱和比对大气水线的影响是不同的.与冰面过饱和比相比,b和d的大小对云中含水量的变化敏感性较低.模拟结果还显示,乌鲁木齐的降水不是来自海洋水汽的初始凝结.在经历了长途输送之后,乌鲁木齐降水中的稳定同位素成分在很大程度上被衰减.模拟的稳定同位素比率/温度、δD/δ18O曲线分别与乌鲁木齐实测的稳定同位素比率/温度回归线以及大气水线有非常好的一致性. 相似文献
88.
介绍的数学模型考虑了混合云中液、固态共存时以及冰面过饱和环境下稳定同位素的动力分馏效应.利用该数学模型,模拟了不同冷却条件下稳定同位素的温度效应.在相同的湿度条件下,湿绝热冷却过程中δ18O随温度的变化率小于等压冷却过程.冰面过饱和比Si的增大意味着动力分馏效应的增大.与平衡态相比,它的作用使得稳定同位素的综合分馏系数减小,从而使得降水中δ18O随温度的变化趋缓.模拟显示,湿绝热冷却过程中大气水线(MWL:=bδ18O+d)的斜率b和常数d均大于等压冷却过程.全球大气水线位于湿绝热冷却过程和等压冷却过程条件下分别模拟的两条大气水线之间.b和d的大小与Si呈正比.Si愈大,动力分馏效应愈强,b和d也愈大.反之亦然.然而,b和d的大小对云中含水量的变化具有低的敏感性.利用动力分馏模式模拟了乌鲁木齐降水中稳定同位素的变化.模拟的稳定同位素比率-温度以及δD-δ18O曲线分别与乌鲁木齐实测的稳定同位素比率-温度回归线以及大气水线有非常好的一致性. 相似文献
89.
Variations of stable isotopic compositions in precipitation on the Tibetan Plateau and its adjacent regions 总被引:15,自引:3,他引:15
There is no temperature effect in the southern Tibetan Plateau and South Asia to the south of the Tanggula Mountains. Amount
effect has been observed at a few sampling stations accounting for about a half of the statistical stations. There is notable
temperature effect in the middle and northern Tibetan Plateau and its adjacent Central Asia to the north of the Tanggula Mountains.
Because vapor directly originates from low-latitude oceans, the relative heavy δ18O with small variation characterizes the rainfall in South Asia. A sharp depletion of the stable isotopic compositions in
precipitation takes place from Kyangjin on the southern slope of the Himalayas to the Tanggula Mountains in the middle plateau.
From the Tanggula Mountains to the northern Tibetan Plateau, the δ18O in precipitation increases with increasing latitude. 相似文献
90.
This paper presents the development of a new type of pseudo-dynamic test system, in which a conventional static jack is utilized for loading. Two of the new hardware devices developed for the system are detailed: a hydraulic pump system that can adjust the rate of oil flow using an inverter motor, and a controller that controls the jack's motion with a displacement feedback signal transmitted from a digital displacement transducer. The unique advantages of the system are summarized as: larger force capacity achieved by the static jack, maximum use of hardware devices available in many existing structural testing laboratories, and flexibility for program development accomplished by separating tasks into multiple PCs. The reliability of the system is calibrated first by a pseudo-dynamic test for an SDOF system and then by a pseudo-dynamic test for a ten-storey building model having hysteretic dampers. For the latter test, substructuring techniques have been incorporated. The accuracy of the results obtained is discussed based upon the capacity of the system to control displacement and comparison with numerical results. 相似文献