WCDMA系统中SPT数字滤波器的一种设计方法

相对于传统的数字滤波器实现方法,符号的2次幂和(SPT)滤波器用移位寄存器替代乘法器,因而资源消耗少、速度快,更加适于专用集成电路(ASIC)设计.介绍了一种适用于宽带码分多址(WCDMA)前向信道中给定基带成形滤波器单位脉冲响应后设计SPT滤波器的方法.相对于传统的理想SPT系数优化方法,此方法更适于给定单位脉冲响应后SPT滤波器的设计,计算复杂度低;仿真结果显示,相对于更加简单的四舍五入方法,此算法在性能上又有可观的增益.     

Micromagnetic simulation of FeCo write head in perpendicular recording hard disk drives

The single-pole tip (SPT) heads made of the high saturation FeCo ferromagnetic metals are crucial for the actualization of ultrahigh density perpendicular recording. The effective head field distribution in the medium is of key importance for the design of the SPT head, which would be analyzed by micromagnetic simulations in this work. Two 3D micromagnetic models of the SPT head were established to select a more appropriate method of modeling, with a magnetostatic image effect or a real soft magnetic material to model the image of the SPT head in soft under layer (SUL). The results from these two designs were tested and compared to the ideal head field calculated by the Jacobi finite element method (FEM); and the design with the real soft magnetic material as image was proved suitable for simulating the ultrahigh density perpendicular recording write head.     

郑州地区粉土承载力确定方法的探讨

结合郑州地区典型岩土工程勘察实例,分析了以往采用理论公式计算法、参数查表法、静力触探参数计算法和载荷试验法等粉土承载力确定方法,探讨其中所存在的局限性。粉土承载力与原位测试值呈近似线性关系,而与土工试验参数相关性相对较差。提出了用原位测试法如标准贯入（SPT）和静力触探（CPT）等确定郑州地区粉土承载力的地域性经验公式。     

基于改进一次二阶矩法的砂土液化判别方法

通过对改进一次二阶矩可靠性分析方法进行研究,提出了一种基于标准贯入击数极限状态方程的地震液化可靠度评估方法,并用Matlab 7．0编制了相应的地震液化概率判别程序。用该可靠性分析方法对1976年河北唐山大地震的资料进行了液化概率分析,并与实测值和规范判别法计算结果进行了对比。结果表明：该方法具有可行性和精确性,为砂土液化势评估提供了一种有效的新方法。     

小冲杆测试材料屈服载荷的有限元分析

文章通过ABAQUS有限元分析软件模拟小冲杆试验过程,重点分析2.25Cr1Mo、16MnR、20#、1.25Cr0.5Mo4种材料的小冲杆屈服载荷。试验结果表明,有限元模拟得到的材料屈服载荷与常规拉伸试验所得出的屈服强度存在显著的线性关系,并具有相当高的相关系数。为最终通过小冲杆试验评价材料的屈服强度提供了一条新的思路。     

用VFP6.0技术调用ORACLE数据库

本文主要讲述在VFP6.0中利用API函数和SPT技术,动态链接ORACLE数据库,调用Orcale9i数据库中的数据表、存储过程和自定义函数的方法和技巧,进而在VFP中进行中间基础数据的输出,以便完成复杂的统计报表输出。     

基于简单性能试验的环氧沥青混合料动态模量研究

为了探索钢桥面铺装用热固性环氧沥青混合料的动态模量规律,首先通过简单性能试验（SPT）分析了不同影响因素下环氧沥青混合料动态模量值的变化规律,并将其同其他常用沥青混合料的动态模量进行对比;进而根据时温等效原理,通过最小二乘拟合分析建立了环氧沥青混合料动态模量的预估模型.结果表明：环氧沥青混合料的动态模量值比相同试验条件下其他材料的动态模量值大,同时,环氧沥青混合料的动态模量值随温度的升高而减小,随加载频率的升高而增大.最后建立了参考温度为20℃时环氧沥青混合料的动态模量主曲线,为环氧沥青桥面铺装的设计与分析提供了材料动态参数.     

Sequencing analysis of a 40·2 kb fragment of yeast chromosome X reveals 19 open reading frames including URA2 (5′ end), TRK1, PBS2, SPT10, GCD14, RPE1, PHO86, NCA3, ASF1, CCT7, GZF3, two tRNA genes,three remnant delta elements and a Ty4 transposon

The complete sequence of a 40 247 bp DNA segment located on the left arm of chromosome X of Saccharomyces cerevisiae has been determined and analysed. The sequence encodes the 5′ coding region of the URA2 gene and 18 open reading frames of at least 100 amino acids. Ten of these correspond to known genes, whereas eight correspond to new genes. In addition, the sequence contains a tRNA-Ala gene, a tRNA-Asp gene, a Ty4 transposable element and three delta elements. The sequence has been deposited in the EMBL databank under Accession Numbers: Z49405, Z49404, Z49403, Z49402, Z49401, Z49400, Z49399, Z49398, Z49397, Z49396, Z49394, Z49392, Z49391, Z49390, Z49389, Z49387, Z49386, Z49385.     

Accounting for the uncertainties in the estimation of average shear wave velocity using V S– N correlations

Site-specific seismic hazard analysis is crucial for designing earthquake resistance structures, particularly in seismically active regions. Shear wave velocity ( V _S) is a key parameter in such analysis, although the economy and other factors restrict its direct field measurement in many cases. Various V _S–SPT– N correlations are routinely incorporated in seismic hazard analysis to estimate the value of V _S. However, many uncertainties question the reliability of these estimated V _S values. This paper comes up with a statistical approach to take care of such uncertainties involved in V _S calculations. The measured SPT– N values from all the critical boreholes were converted into statistical parameters and passed through various correlations to estimate V _S at different depths. The effect of different soil layers in the boreholes on the Vs estimation was also taken into account. Further, the average shear wave velocity of the top 30 m soil cover ( V _S30) is estimated after accounting for various epistemic and aleatoric uncertainties. The scattering nature of the V _S values estimated using different V _S– N correlations was reduced significantly with the application of the methodology. Study results further clearly demonstrated the potential of the approach to eliminate various uncertainties involved in the estimation of V _S30 using general and soil-specific correlations.     

塔式太阳能热力发电技术进展

开发和利用太阳能是当今世界新能源技术革命所面临的重大课题,尤其是太阳能热力发电对人类环境的改善和电力行业可持续发展具有重要的战略意义,必将成为本世纪一种重要能源产业.为此,在比较3种太阳能热力发电系统性能的基础上,阐述了塔式太阳能热力发电系统的发展历程和特点,介绍了塔式热力发电的基本原理及其示范电站的技术进展,着重分析了塔式热力发电所涉及的关键技术,包括太阳热能定日镜、受热器和高温热能储存技术.通过对关键技术的分析,指出大规模高温热能储存是实现太阳能热力发电需优先解决的关键技术,同时提出了发展中国塔式太阳能热力发电技术所需相关基础研究的建议.