庐陵古村落建筑的园林化特色

园林艺术作为一种传统乡居追求,历史上首先出现于我国北方,而南宋以降随着经济文化中心的南移,大批中原人士涉江而来.为赣江流域的庐陵先民.诗书传家"提供了优越条件,形成了蜚声遐迩的庐陵文化,建筑文化是庐陵文化的一个重要组成部分.而庐陵古村落建筑的园林化,是庐陵建筑文化的一大特色.进行庐陵古村落乡土建筑文化的研究,不仅对发掘、保护以及利用现存的古村落建筑具有非常重要的理论价值,同时对当代村镇的规划建设亦具有积极的现实意义.     

最优投保决策模型研究

当购买死亡保险时, 投保人需要选择投保的期限. 以平均收益与风险的和为目标函数, 讨论了在给定年龄x和安全载荷ρ的条件下,如何选择投保期限才能使得目标函数达到最大值.同时利用数值计算结果讨论了年龄对最优投保期限的影响.     

英汉词汇搭配现象的异同比较

语言中能够独立运用的最小表义单位是词,因为词是“语言的最小的独立运用的意义单位”。对词汇搭配的研究是研究词的一个基本的重要内容,汉语和英语两种语言搭配有各自的特点,同时,二者也有共同之处。通过研究汉英词汇搭配中的某些现象,比较二者的相似与不同之处,旨在揭示英汉两种语言在语法规律以及语义范围等方面的特殊规律,对英语教学和翻译研究有一定的指导意义。     

基于进化人工神经网络的组合系统滤波技术

在组合系统运用Kalman滤波器技术时,准确的系统模型和可靠的观测数据是保证其性能的重要因素,否则将大大降低Kalman滤波器的估计精度,甚至导致滤波器发散.为解决上述Kalman应用中的实际问题,提出了一种新颖的基于进化人工神经网络技术的自适应Kalman滤波器.仿真试验表明该算法可以在系统模型不准确时、甚至外部观测数据短暂中断时,仍能保证Kalman滤波器的性能.     

绿洲-荒漠生态系统演化因素及其非线性探讨——以新疆为例

对立统一于干旱区的绿洲—荒漠生态系统在降水等自然因素和人类活动等人为因素的影响下不断进行着演化.从长期看,这一演化过程具有不可预测性,短期内却有细微可预见性.现如今在绿洲扩展同时,荒漠也在扩展,整体趋势仍是荒漠在扩展.为维持绿洲的稳定性,促使绿洲—荒漠系统处于一种稳定的发展趋势,本文从分析绿洲-荒漠这对对立统一的生态系统入手,在探讨引起这对生态系统演化的自然因素和人为因素的基础上,确定了自然因素中的降水和人为因素中的政府调控行为为演化的主导因素,初步探索了促使这对生态系统统演化的主导因素作用所具有的非线性关系,这对维持绿洲的稳定性,抑制荒漠扩展有一定的实际意义.     

Performance of various activators in ethylene polymerization based on an iron(II) catalyst system

Ethylisobutylaluminoxane (EBAO) and its analogues were synthesized by a reaction between an triethylaluminum (Et₃Al)/triisobutylaluminum (i‐Bu₃Al) mixture and 4‐fluorobenzeneboronic acid, phenylboronic acid, or n‐butaneboronic acid and subsequent hydrolysis with water. They were used as cocatalysts in ethylene polymerization catalyzed by an iron complex {[(ArN?C(Me))₂C₅H₃N]FeCl₂, where Ar is 2,6‐diisopropylphenyl}. Polyethylene with a high molecular weight and a narrow molecular weight distribution was prepared with modified EBAOs, and the performance of the iron complex at high polymerization temperatures was greatly improved. The activators for the iron complex also affected the polymerization activity and the molecular weight of the resultant polyethylene. It was suggested that the stereo and electronic effects of the substitute groups of aluminoxane contributed to the improved performance of the new activators. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1093–1099, 2004     

Time-resolved chemiluminescence technique for the microdetermination of proteins based on their complexation with copper(II).

Based on the complexation between proteins and Cu(II) coupled with the time-resolved chemiluminescence (CL) technique, a highly sensitive and quantitative assay for measuring proteins in solution is described. The complexes of proteins with Cu(II) have a strongly catalytic effect on the luminol-H2O2 CL reaction. Because the CL emission produced by the complexes is much more long-lived than that by Cu(II), the CL signals originating from proteins can be easily identified and measured with a time-resolved technique. On this basis, bovine albumin fraction V (BAF V) can be quantitatively determined in the range of 0.01 - 5.0 microg/ml with a detection limit of 5.8 ng/ml. The results show that the proposed assay exhibits a small variation in the response values for the same amount of different proteins, as compared to the Lowry as well as Bradford assays. The CL assay has also been studied for the detection of immobilized proteins.     

X波段六腔渡越管振荡器的高频特性研究

 从麦克斯韦方程出发，采用时域有限差分法（FDTD）和离散傅里叶变换（DFFT）相结合的方法，通过数值计算得出了六腔开放式谐振腔中前四个谐振频率和场分布，计算出的谐振频率与实验测量结果基本相同。比较了开放腔和封闭腔谐振频率，验证了TEM波吸收边界条件，并在实际编程计算中得以应用。计算结果为六腔渡越管振荡器的机理研究提供了依据。     

爆磁压缩发生器通过脉冲变压器对脉冲形成线充电的理论分析

 将爆磁压缩等效为电流源的方法，对爆磁压缩发生器通过脉冲变压器对脉冲形成线充电进行了理论分析，得出爆磁压缩发生器在负载上产生电流波形（简称负载电流）为直线情况和任意电流波形情况下充电电流和充电电压的表达式。分析表明变压器耦合互感与负载电流随时间变化增长率是脉冲形成线充电的两个重要参数，脉冲形成线第一个充电电压峰值与变压器的耦合互感和负载电流波形斜率成正比，负载电流波形斜率的变化可以改变充电电压峰值的时间，斜率不断增加可以延长第一个充电电压峰值时间，从而可能增加充电电压的幅值，提高爆磁压缩发生器能量的利用效率。