对宋词《如梦令·争渡》及其英译文的主位分析

翻译研究的功能语言学途径发现,对源语语篇与目的语语篇主位结构的分析可以为翻译质量在信息传递方面的表现提供借鉴.本文通过对宋词《如梦令·争渡》及其两篇英语译文的主位结构分析比较,从信息结构方面对译文质量做出了客观评价,从而证明功能语篇分析在翻译研究中的实践性和可操作性.     

盲源分离技术的发展及应用浅谈

盲源分离是指在不知道源信号和传输信道任何先验知识的情况下,仅根据输入源信号的统计特性,通过观察信号恢复出各个独立源信号的过程。文章简要介绍了盲源分离的基本思想、概念及数学模型,并对目前在盲源分离研究中,几个关键问题取得的研究成果与进展进行了讨论。     

Theoretical studies on the space CIV experiment over China

Recently the Active Experiment Working Group, Center for Space Science and Applied Research, has proposed a chemical release experiment program. The initial scientific object of the program is to study the critical ionization velocity (CIV) mechanism at low and middle latitudes over China. Beside of the development of the chemical module system, theoretical studies on the CIV phenomena of barium or strontium released over China are studied. We found that the angle between the release velocity and the ambient magnetic field over China is smaller than that in the same latitude region in North America and is advantageous for studying CIV phenomena and the evolution of ionized cloud along the magnetic lines. We also used a numerical simulation to simulate the evolution of chemical release clouds under various release conditions. For 1 kg barium and V-B angle equal to 60 degrees, we have a better configuration of ions cloud which can easily distinguish the ions created by CIV phenomena from that by the UV of the sunlight.     

应力St）为Poisson更新过程时结构可靠度

本文讨论应力Ｓ（ｔ）为Ｐｏｉｓｓｏｎ更新过程时结构可靠度。获得在设计基准期（０，Ｔ）内重复应力循环发生次数服从Ｐｏｉｓｓｏｎ更新过程时结构可靠度达表式。     

医院信息系统的网络总体方案

设计医院信息系统网络总体方案，包括网络技术、网络设备、服务器的选型，数据库服务器操作系统及数据库软件系统的设计，数据完全备份系统的设计。     

用于失谐叶盘动力学特性分析的减缩计算方法

提出了一种用于失谐叶盘动力学特性分析的减缩计算方法.该方法采用基于周期对称的谐波平衡法,建立非线性的迭代方程,能够基于单扇区的矩阵求解整个失谐叶盘的强迫响应,且不存在任何截断误差,因而效率高于部件模态综合法但精度并不降低.从周期对称结构理论出发给出了方法原理的数学推导,在此基础上通过一个失谐叶盘有限元模型算例对该方法的效率与精度进行了讨论.结果表明:相较部件模态综合法,周期对称谐波平衡法矩阵维度减小59.5%,计算复杂度减少93.4%,计算时间节省57.4%.     

两轮升压式涡轮冷却器特性试验研究

针对两轮升压式涡轮冷却器的特点制订了涡轮和压气机的特性试验方案,分别按照折合参数整理了涡轮和压气机的特性试验数据,利用曲面拟合分别得到了涡轮和压气机的特性曲面方程。将10个校核点的试验数据与曲面方程得到的数据对比,误差在5%以内,证明试验方法和数据处理方法合理可行,对类似产品的特性试验具有借鉴意义。     

Design and implementation of five-axis transformation function in CNC system

To implement five-axis functions in CNC system, based on domestic system Lan Tian series, an improved design method for the system software structure is proposed in this paper. The numerical control kernel of CNC system is divided into the task layer and the motion layer. A five-axis transformation unit is integrated into the motion layer. After classifying five-axis machines into different types and analyzing their geometry information, the five-axis kinematic library is designed according to the abstract factory pattern. Furthermore, by taking CA spindle- tilting machine as an example, the forward and the inverse kinematic transformations are deduced. Based on the new software architecture and the five-axis kinematic library, algorithms of RTCP （rotation tool center point control） and 3D radius compensation for end-milling are designed and realized. The milling results show that, with five-axis functions based on such software struc- ture, the instructions with respect to the cutter＇s position and orientation can be directly carried out in the CNC system.     

低轨航天器长期轨道预报的初步研究

低轨航天器的长期管理和维护需要较高精度的长期轨道预报,影响长期预报精度最主要的因素来自低轨航天器所受的大气阻力摄动.借助平均大气密度模型,以340 km高度的低轨航天器为例,研究了低轨长期轨道预报问题.利用基于长弧段的逐天精密定轨,可以修正参考点的平均密度.根据目前积累的数据,通过引入太阳自转周期27 d和半年180 d这2个周期拟合平均密度序列,未来的平均密度可以预报到较高精度.目前的计算结果表明,在此基础上低轨航天器的长期轨道预报精度可以得到保证,在不同算例中表现基本稳定可靠.     

MIMO系统下一种改进的 LatticeReduction线性预编码算法

现有LR(Lattice Reduction)辅助的线性预编码算法,在接收机端需要对接收到信号进行平移变换,因而仅适合于点对点的MIMO系统中,然而在广播信道条件下,由于接收机是分散的,且功率尺寸受限,不适宜采用现有的线性预编码算法。针对这一问题,文章提出了一类改进的LR辅助线性预编码算法,并给出了相应ZF和MMSE准则下的具体实现。在该算法中,信号处理主要在发送机端完成,以降低接收机端的计算量。仿真结果表明:文章提出的算法相比现有的LR辅助线性预编码算法误比特率性能更好,因而更适用于广播信道条件下的MIMO系统。