空间打击-空间力量使用的前景

美国空军未来的最重要和有争议的任务这一就是“空间力量的使用”；用来自空间和通过空间飞行的武器打南地球上的目标。从历史上讲，能执行这种任务和只有带核弹头的洲际弹道导弹的战略使用。但是，在不久的将来，使用力量和任务可能包括各种类型的武器，弹药和学说。目前用来攻击象地下化学武器工厂这样的硬目标的常规弹道导弹正在积极研制之中。

中国在国际体系中的地位与作用

中国目前已加入各种国际组织、国际制度,正加速融入国际体系,但这不意味着中国在国际体系中的作用问题也随之解决。本文区分了“中国加入国际体系”和“中国在国际体系中发挥作用”这二者之间的不同内涵,认为中国加入国际体系的问题基本得到解决,而在国际体系中的作用问题在国内则尚未解决,甚至还没有引起国内学术界的足够重视。在此基础上,文章就中国应该在国际体系中发挥什么作用以及如何发挥作用等问题作了探讨。

俄罗斯要修改军事战略吗？

2001年美国发生“9·11”恐怖袭击事件和阿富汗反恐战争，特别是2002年10月莫斯科发生大规模劫持人质事件后，俄罗斯开始重新评估国家安全面临的威胁，决定对国家安全构想作出修改：在继续作好应对武装冲突和战争准备的同时，重视现实的恐怖主义威胁，修改武装力量使用计划和作战方式。

Replacing Stirrups of Self-Compacting Concrete Beams with Steel Fibers

Based on the investigation of fiber influence on workability of self-compacting concrete (SCC), tests were carried out on two series of SCC rectangular simply supported beams, which were made of hooked steel fibers reinforced concrete with or without stirrups, subjected to four-point symmetrically placed vertical loads. The major test variables are steel fiber contents and stirrup ratios. The results indicate that the ultimate load significantly increases with the increase of fiber content; the addition of ...

Damage detection of frames using the increment of lateral displacement change

The method proposed in this paper is based on the fact that the damage in different types of structural members has distinctive influence on the structural stiffness. The intrinsic mechanical property of the structure is tapped and fully utilized for damage detection. The simplified model of the flexibility of frames treats the individual storeys as springs in series and the frame as an equivalent column. It fully considers the main deformation of all beams and columns in the frame. The deformation property of the simplified model accorded well with that of the actual frame model. The obtained increment of lateral displacement change (IOLDC) at the storey level was found to be very sensitive to the local damage in the frame. A damage detection method is pro- posed using the IOLDCs as the damage identification parameters. Numerical examples demonstrate the potential applicability of this method.

Recovery of the gravity field from GOCE data by using the invariants of gradient tensor

The gravity field models GUCAS_EGM and GUCAS_EGM_DL are established from GOCE data (GOCE Level 2 Products from Nov. 1 to Dec. 31, 2009) based on the method of the invariants of the gravity gradient tensor, where GUCAS_EGM is derived after GOCE gravity gradient data are filtered with FIR, and GUCAS_EGM_DL is computed with an additional Durbin-Levison arithmetic apart from FIR. Since this method, different from current programs dealing with GOCE data, is introduced for the first time, some new problems are required to be discussed in advance; for example, how to filter GOCE gravity gradient data, how to compute the invariants of the gradient tensor, and how to deal with the pole gap and so on. In addition, by comparing our models with ones recommended by ESA, it can be seen that the variations of GUCAS_EGM and the models recommended by ESA to EGM08 are almost equivalent, and the variation of GUCAS_EGM_DL to EGM08 is obviously less than ones of the recommended models.

Partial energies monotonicity and holomorphicity of Hermitian pluriharmonic maps

In this paper, we introduce the notion of Hermitian pluriharmonic maps from Hermitian manifold into Kiihler manifold. Assuming the domain manifolds possess some special exhaustion functions and the vecotor field V = JMδJM satisfies some decay conditions, we use stress-energy tensors to establish some monotonicity formulas of partial energies of Hermitian pluriharmonic maps. These monotonicity inequalities enable us to derive some holomorphicity for these Hermitian pluriharmonic maps.