基于Kanai-Tajimi模型的地震作用荷载新型识别方法

目的研究一种识别地震作用荷载的方法,为地震作用荷载的识别与相应结构的动力特性、损伤的识别提供一种新的途径,进一步为结构的安全性、损伤进程和耐久性等研究提供理论参考.方法利用Kanai-Tajimi模型将单位强度白噪声过程模拟为未知的地震作用,并将其作用在结构上,然后根据数值模拟计算得到的结构体系响应作为观测量,采用Kalman滤波对未知荷载状态加以识别.结果最终可以利用结构的加速度响应反演得出地震作用的等效荷载,在人工添加5%观测噪声的条件下,最大误差率为7%左右,而在人工添加10%观测噪声的条件下,最大误差率为8%左右.结论通过算例的验证,说明笔者所采用的方法精度较高,获得了较好的识别效果.     

大截面板簧和稳定杆的热处理改进

合理选择淬火冷却介质和确定零件的材料产品质量取于受控状态和确保产品质量的提高。     

Formation and thermal stability of amorphous Ni-Mo-P alloys

The experimental researches on the chemical deposition of Ni-Mo-P amorphous alloys were carried out by adding Na2 MoO4 into acidic solutions. The optimum technology conditions were obtained by orthogonal design experiments. The structures and the relationship between compositions and their thermal stability were studied by energy spectrum (EC), scanning electron micrograph and X-ray diffraction spectrum. Compared with Ni-P amorphous alloys, the Ni-Mo-P amorphous alloys have high crystallization temperature and thermal stability, and the hardness reaches its peak when the annealing temperature is 500 ℃. With the increase of the heat treatment temperature, the surface morphology of the alloys changes.     

基于CCD技术的外观纸病检测系统

设计了CCD在线外观纸病检测系统,介绍了该系统的硬件组成情况和系统的工作原理、技术指标和软件设计,重点阐述了外观纸病检测系统中CCD技术的优势。     

P distribution in different sediment fraction of a constructed wetland

The aim of this work was to study the accumulation and fractionation of P in the inlet and outlet sediment of a constructed wetland for the wastewater treatment of a metallurgic plant in Argentina. It was important to predict whether P could be released into the water again by changing environmental conditions or retained over time. P-fractionation was performed using a sequential extraction method. Sediment cores were sliced at depths of: 0-3; 3-7 and 7-10 cm. Sediment showed high pH values and anoxic conditions. In the inlet area, P was principally bound to the carbonate fraction, whereas in the outlet area, it was mainly bound in the residual fraction. This behavior was justified by the effluent composition, which is rich in Ca2+ and Fe3+ and presents high values of pH and conductivity. These conditions favor CaCO3 and Fe(OOH)n precipitation and the subsequent sorption of P to their surface. The sediment active layer involved in the exchange reactions was the superficial one (0-3 cm). The wetland is highly efficient in P retention. P was retained by sediment in fractions that will not release it to the water while chemical and environmental conditions of the system are maintained.     

Study of diffusion mobilities of Nb and Zr in bcc Nb–Zr alloys

On the basis of the available thermodynamic parameters, the atomic mobilities of Nb and Zr in bcc Nb–Zr alloys are critically assessed as functions of temperatures and compositions by the CALPHAD method, where self-diffusion coefficients, impurity diffusion coefficients, tracer diffusion coefficients, interdiffusion coefficients and concentration curves are simultaneously optimized. Comparisons between the calculated and experimentally measured diffusion coefficients are made, where good agreement is evident. In addition, the obtained mobility parameters can reproduce a reasonable concentration profile for the Nb/Zr diffusion couple annealed at 1868 K for 5400 s.     

遗传算法与文本特征选择方法相结合的研究

对文本特征选择的传统方法进行了深入分析并对各自的优缺点进行了详细的对比;其次,通过利用遗传算法自身的寻优特点,把它与传统特征选择方法相结合,并得出了算法。最后,在对各自算法进行了分析,表明了在性能上有了明显的提高。     

基于ARM处理器的PC/104总线嵌入式计算机的设计

本文介绍了基于ARM处理器的PC/104总线嵌入式计算机的构成,对ARM实现PC/104总线嵌入式计算机技术进行了研究。最后,描述了用ARM处理器替代X86在工业控制领域应用的方法和具体设计。