PLC仿真软件在涡流探伤电气系统设计中的应用

分析了涡流探伤系统和工艺流程,介绍了在涡流探伤电气系统中PLC输入输出信号地址的分配情况,然后基于对S7-PLCSIM界面的描述,利用S7-PLCSIM仿真实际的S7-300 PLC。实例表明：仿真结果与涡流探伤中实际的PLC运行一致,因此在电气系统设计过程中可利用S7-PLCSIM来查看程序的运行状况。     

DC-DC电力变换器设计与实现

DC-DC是将不可调的直流电压转变为可调或固定的直流电压,是一个用开关调节方式控制电能的变换电路,这种技术被广泛应用于各种开关电源、直流调速、燃料电池、太阳能供电和分布式电源系统中。上个世纪,随着功率开关器件的发展,变换器拓扑和变换技术已经取得了很大的成就,并且已经发展到一个相当高的水平。在DC-DC变换器的演化过程中,离不开各种直流变换技术,各种新技术的产生和发展很大程度上影响了变换器拓扑的演化。本课题的目的是设计一种DC-DC电力变换器,其可将一种直流电变换为另一种形式直流电,并利用MC9S08DZ60单片机对其进行控制,主要对电压、电流实现变换,它在可再生能源、电力系统、交通、航天航空、计算机和通讯、家用电器、国防军工、工业控制等领域有广泛的应用。     

CISA 3D Navier—Stokes程序在压气机中的鉴别和应用

用压气机叶栅试验数据、多级压气机的第4级静子计算结果和跨声速转子试验结果对CISA 3D N-S程序的计算精度进行了鉴别研究。结果表明,该程序对设计点的落后角的计算精度较高,而对损失的计算还存在一定的分散度。采用 CISA 3D N-S程序和S_2-S_1程序对一台多级压气机试验件的第3级静子进行三维造型修改设计,取得了预期的效果。     

应用S4000P制订民用飞机区域检查任务方法探究

介绍了S4000P制订和持续改进预防性维修任务国际规范，分析了S4000P的区域分析方法，探究了S4000P在制订民用飞机区域检查任务方面的应用方法，并给出了应用S4000P的区域检查任务的直接维修成本预计策略。     

eCos操作系统针对并行S698P-SOC的启动初始化过程研究

实时操作系统eCos是一款嵌入式操作系统。eCos支持多核并行处理系统,但是对多核处理器存在一些限制。多核处理器S698P-SOC满足eCos对处理器的限制要求。eCos在S698P-SOC上的启动初始化过程包括主CPU的启动和从CPU的启动两部分。     

转向工况下汽车操纵稳定性的研究

文章利用Adams/View软件建立了某车的整车仿真模型,该模型考虑了转向系统和悬架系统。采用转向盘角阶跃输入函数作为转向盘的转角输入,对整车模型进行仿真试验,着重研究了转向汽车的操纵稳定性,分析了静态储备系数和前悬架刚度对汽车操纵稳定性的影响。     

A multi-wavelength study of the merger candidate Abell S0721 and the activities of its member galaxies

We present a multi-wavelength study of the merging history and its influence on galaxy activities of a newly detected merger candidate – Abell S0721. This cluster was only known as a poor cluster in the Shapley Supercluster, but when several survey data of different wavelengths are combined, evidence of strong merging is revealed. We have analyzed the optical and X-ray structures of the cluster, as well as galaxy dynamics and properties of the radio galaxies in the cluster. The dynamics analysis shows the velocity distribution of this system is significantly deviated from a 1-Gaussian model, indicating the existence of 2–3 dynamically different sub-systems; in addition, both optical and X-ray structures of the cluster show an elongated and multi-clump structure, two X-ray clumps imaged by ROSAT All Sky Survey are well correlated with two galaxy density peaks. This cluster is possibly a merger of several groups; our analysis shows that the projection angle for two clumps in the main structure is possibly near the projection plane, and the substructure is seen at ∼30–75° from the projection plane. The merging process could also be the origin to boost the activities of its member galaxies. Finally, as compared with other merger candidates in the Shapley Supercluster, the radio galaxies identified in Abell S0721 are all optically luminous, and the fraction of luminous radio galaxies is only lower than one merger candidate (which is proposed to be at the very beginning of a merger event), this suggests Abell S0721 is also at the beginning of a merger event.     

Comparison of ground reflectance measurement with satellite derived atmospherically corrected reflectance: A case study over semi-arid landscape

Atmospheric corrections to satellite data are important for comparing multitemporal data sets over tropical regions with variable aerosol loading. In this study, we evaluated the potential of 6S radiative transfer model for atmospheric corrections of IRS-P6 AWiFS satellite data sets, in a semi-arid landscape. Ground measurements of surface reflectance representing different land use/land cover categories were conducted to relate IRS-P6 AWiFS top of atmospheric reflectance. The 6S radiative transfer model was calibrated for local conditions using ground measurements for aerosol optical depth, water vapor and ozone with a sun photometer. Surface reflectance retrieved from 6S code was compared with top of atmosphere (TOA) reflectance and ground based spectroradiometer measurements. Accurate parameterization of the 6S model using measurements of aerosol optical depth, water vapor and ozone plays an important role while comparing ground and satellite derived reflectance measurements.     

任意K元Huffman树的新构造

给出了一种简单而有效地构造任意k元最优Huffman树的新方法。给出了Huffman村存贮的父母一子女环结构,该结构空间利用率高,在不增加parent域的情况下,使查找父母的T（m）达到O（1）,并能高效实现建立最优Huffman树和求Huffman编码的算法,无论是空间复杂度还是时间复杂度均优于传统算法,具有很强的实用性。