节水型春小麦新品种高原584及其栽培技术

高原584是中国科学院西北高原生物研究所生态农业研究中心郜和臣研究员等培育的节水型春小麦新品种，原代号91D58-4，1999年11月25日经青海省农作物品种审定委员会审定通过，定名为"高原584"，2003年2月26日又通过甘肃省农作物品种审定委员会第十九次会议审定。

Temperature measurement of reflected shock wave by using chemical indicator

This report describes a new method for measuring the temperature of the gas behind the reflected shock wave in shock tube, corresponding to the reservoir temperature of a shock tunnel, based on the chemical reaction of small amount of CF4 premixed in the test gas. The final product C2F4 is used as the temperature indicator, which is sampled and detected by a gas chromatography in the experiment. The detected concentration of C2F4 is correlated to the temperature of the reflected shock wave with the initial pressure P-1 and test time tau as parameters in the temperature range 3 300 K < T < 5 600 K, pressure range 5 kPa < P1 <12 kPa and tau similar or equal to 0.4 ms.

Generalized Maugis-Dugdale Model of an Elastic Cylinder in Non-Slipping Adhesive Contact with a Stretched Substrate

We have recently developed a generalized JKR model for non-slipping adhesive contact between an elastic cylinder and a stretched substrate where both tangential and normal tractions are transmitted across the contact interface. Here we extend this model to a generalized Maugis-Dugdale model by adopting a Dugdale-type adhesive interaction law to eliminate the stress singularity near the edge of the contact zone. The non-slipping Maugis-Dugdale model is expected to have a broader range of validity in comparison with the non-slipping JKR model. The solution shares a number of common features with experimentally observed behaviors of cell reorientation on a cyclically stretched substrate.

Dynamic mode I perturbation solution for a moving crack unsteadily

Rice et al. (Jounal of Mechanics and Physics of Solids 42, 813-843) analyze the propagation of a planar crack with a nominally straight front in a model elastic solid with a single displacement component. Using the form of Willis er al. (Journal of the Mechanics and Physics of Solids 43, 319-341), of dynamic mode I weight functions for a moving crack, we address that problem solved by Rice ei al. in the 3D context of elastodynamic theory. Oscillatory crack tip motion results from constructive-destructive interference of stress intensity waves. Those waves, including system of the dilatational, shear and Rayleigh waves, interact on each other and with moving edge of crack, can lead to continuing fluctuations of the crack front and propagation velocity. (C) 1997 Elsevier Science Ltd.

用量子Monte Carlo方法计算氢分子H_2基态(Χ~1∑_g~+)势能曲线

本文用量子MontoCarlo方法中优化试探波函数Ψ_T计算氢分子H_2基态(X~1∑_g~+)势能曲线.文中采用相当简单的波函数形式,并用固定样点优化技术优化试探波函数的参数.确定优化试探波函数后,分别用变分Monte Carlo及固定节面M0nte Carlo计算势能曲线各点能值.二种方法先后得95%和100%的相关能.因此,在量子M0nte Carlo方法中,用本文作者提出的试探波函数计算分子势能面,将会获得很好的结果.从而对分子散射和动力学的研究有重要意义.

边界元法在求解复合材料力学问题中的应用

本文讨论了边界元法在求解复合材料的微观力学、宏观力学和结构力学问题中的应用,并指出边界元法用于分析复合材料及其结构的力学问题的优点和局限性。

损伤材料裂纹尖端附近的应力场

本文导出了损伤材料的全量理论,导出了全量公式中H的渐近表达式;最后得到损伤材料平面应变条件下的裂纹尖端的应力应变场。

二阶非线性微分方程亚/超谐共振的一种求解方法及其应用研究

本文引用了非线性共振频率的概念,指出如何求主共振频率域及其中心。采用新的办法对单自由度非线性系统的亚/超谐共振进行了研究。作为例子讨论了Duffing方程,给出了1/7,1/5,1/2,3/5,5/3,2,5次谐波共振的结果。模拟计算机的计算结果对所给理论作了部分验证。

Non-die explosive forming of spherical pressure-vessels

This paper presents a newly developed method of manufacturing spherical pressure vessels based on the technology of non-die explosive forming. Compared with the traditional method, this technology does not need any dies and pressing equipment, so that the cost of the production process can be greatly reduced, especially for vessels of less than 100 m3 capacity.

On the invariant representation of spin tensors with applications

The invariant representation of the spin tensor defined as the rotation rate of a principal triad for a symmetric and non-degenerate tensor is derived on the basis of the general solution of a linear tensorial equation. The result can be naturally specified to study the. spin of the stretch tensors and to investigate the relations between various rotation rate tensors encountered frequently in modern continuum mechanics. A remarkable formula which relates the generalized stress conjugate to the generalized strain in Hill's sense. to Cauchy stress, is obtained in invariant form through the work conjugate principle. Particularly, a detailed discussion on the time rate of logarithmic strain and its conjugate stress is made as the principal axes of strain arc not fixed during deformation.

欠膨胀超声速射流不稳定性机理的数值研究

应用NND有限差分格式求解轴对称可压缩N-S方程,研究了不同驻室与环境压力比条件下欠膨胀超声速射流近场的失稳特性.计算结果表明欠膨胀超声速射流的失稳机制根据射流激波结构的特征可分为3种失稳模式:具有规则反射激波结构和单一剪切层特征的射流不稳定性;带有马赫反射激波结构和双剪切层特征的射流不稳定性;具有弯曲马赫杆和高度欠膨胀射流的不稳定性.对于欠膨胀超声速射流,沿射流方向重复出现拟周期性的射流激波结构是射流稳定发展的特征,这种射流激波结构的消失是射流开始失稳的标志.

压电类智能梁元的优化布局

分别对具有无限小长度驱动器的悬臂和简支智能梁的一阶模态和二阶模态进行了具体的分析和计算，确定了驱动器在梁元中的最优布局，总结了有关驱动器在梁元中布局的一些基本性质，并从解析的角度对驱动器的最优布局点给予解释。由于以上有关驱动器最优布局的分析是在忽略驱动器的长度的假设基础上进行的，所以又对有限长度的驱动器的布局问题进行了初步的探讨。

Adiabatic shear localization: occurrence, theories, and applications