12层剪力墙结构楼房爆破拆除

采用定向爆破拆除12层剪力墙结构楼。通过计算选择合适的爆破参数,在条件受限的情况下采用电与非电起爆网路,并采取了安全防护措施。爆破效果良好,为类似工程提供了借鉴。     

谐波信号频率的混沌检测方法

该文针对实际中大量存在的未知谐波信号频率,提出用非线性混沌动力学系统检测的方法;先从非线性方程理论出发论证系统存在周期解;然后建立仿真模型,用定向过零技术计算谐波频率;经过对计算结果绝对误差与相对误差的分析,得出该项技术是可行的。同时提出在检测频率后,进一步检测谐波幅值的可能性。     

Effects of electromagnetic vibration on the structure and mechanical properties of Al-6%Si alloy during directional solidification

The effects of electromagnetic vibration on the grain refinement in directional solid- ification were investigated. It was found that the electromagnetic vibration applied in the melt not only can refine grains remarkably but also can enhance both tensile strength and ductility values of Al-6%Si alloy. SEM graphs show that coarse dendrite structure was broken up into a somewhat globular structure, and the morphology of eutectic silicon was changed from flaky to fibrous under electromagnetic vibration treatm...     

激光二坐标测量装置显微视觉关键技术的研究

为满足二维线纹标准器高精度检测需求,研究了激光二坐标测量装置的显微视觉系统关键技术.分析了激光二坐标测最装置的工作原理和显微视觉硬件系统的构成,提出了一种基于方向链码的边缘特征点跟踪提取算法,实现了图像边缘快速精确提取,建立了两坐标系间的修正模型,提高了测量精度.实验验证二维线纹标准器线间距和线宽测量重复性的2倍标准差小于10 nm.     

太阳能电池多晶硅铸锭的凝固原理和方法浅谈

首先从定向凝固的原理讲起,其中涉及定向凝固的一些重要的工艺参数以及多晶硅铸锭的组织结构;其次,介绍了多晶硅铸锭的几种凝固方法,尤其着重讲了一下热交换法的应用;并在结尾提到了现在铸锭法中需要改进和解决的主要问题。     

Perturbed polynomials with zeros in the left-sector

We investigate the directional perturbation of a real nominal polynomial. We propose an algorithm for computing the largest allowable perturbation bound which will simultaneously maintain the zeros of the perturbed polynomial within the left-sector in the complex plane.     

70m砖烟囱定向爆破拆除及结果分析

爆破拆除一座 70m高的砖结构烟囱时 ,该烟囱没有按预期的方向倾倒。文中介绍了设计方案、实际爆破参数以及爆破效果 ,并对爆破中烟囱的实际倒塌结果与设计要求不一致的原因作了详细的分析。     

关于ICRU39号报告中的辐射量的讨论

本文介绍了 ICRU39号报告中提出的用于场所监测和个人剂量监测的四个辐射量的概念和特性,分析了它与以往的用剂量当量指数量方案的差别和改进之处,指出了它在实用中还存在的一些困难和应用中尚须注意的问题。     

High level communication functionalities for wireless sensor networks

In this paper we show how to establish a reliable and efficient high level communication system in a randomly deployed network of sensors equipped with directional antennas. This high level communication system enables the programming of the sensor network using high level communication functionalities without the burden of taking care of their physical capacities (low range, unidirectional links, single frequency, presence of collisions, etc.). The high level communication functionalities we offer include point-to-point communication, point-to-area communication, and one-to-all communication. The basic idea to implement this system is to simulate a virtual network that emerges from the ad-hoc network using self-organization, self-discovery and collaborative methods. We also analyse the efficiency, scalability and robustness of the proposed protocols.     

Modelling asymmetry in the peripheral auditory system of the lizard

The ears of lizards are highly directional. The directionality is generated by strong acoustical coupling of the eardrums. A simple lumped-parameter model of the ear followed by binaural comparisons has been shown to perform successful phonotaxis in robot implementations. However, such a model will produce localization errors in the form of response bias if the ears are asymmetrical. We have evaluated how large errors are generated by asymmetry using simulations of the ear model in Mathematica 5.2. The study shows that the effect of asymmetry is minimal around the most directional frequency of the ear, but that biases reduce the useful bandwidth of localization. This work was presented in part at the First European Workshop on Artificial Life and Robotics, Vienna, Austria, July 12–13, 2007