一维抛物型偏微分方程 Padé 逼近的并行算法

一维抛物型偏微分方程可以用精细积分方法精确求解．当精细积分中的矩阵指数函数用它的Ｐａｄé逼近格式来代替时,可以得到一系列由简到繁,精度由低到高的差分格式,因而便于根据实际计算的需要进行选取．Ｐａｄé逼近格式的求解主要包括矩阵运算和线性方程组的求解．利用Ｐａｄé逼近格式对应的方程组系数矩阵为带状矩阵的特点,把原来在整个区域上求解的问题转化为分区域求解,从而实现了Ｐａｄé逼近的并行算法．算例的结果表明该方法具有较高的并行性和计算效率     

节流毛细管设计的类比法

从毛细管的微分方程模型出发，建立了绝热毛细管类比设计法的理论公式，提高了毛细管的设计效率。     

Switched Capacitor Network Analysis by Means of TCM

The totally coded method (TCM) reveals the same objective law, which governs the gain calculating for signal flow graph as Mason formula does. This algorithm is carried out merely in the domain of code operation. Based on pure code algorithm, it is more efficient because figure searching is no longer necessary. The code-series (CS), which are organized from node association table, have the holoinformation nature, so that both the content and the sign of each gain-term can be determined via the coded method. The principle of this method is obvious and it is suited for computer programming. The capability of the computeraided analysis for Switched Capacitor (SCN) can be enhanced.     

串行红外链路接入协议关键参数的优化

给出了使串行红外链路接入协议(IrLAP)吞吐量最大的关键参数的最优化数值解法．在该方法所得的发送窗口大小和信息帧信息字段长度下，IrLAP的吞吐量大于相关文献中的理论近似结果，并得到发送窗口大小是决定IrLAP吞吐量性能最关键参数的结论。     

价格系统及其稳定性研究

本文基于产品的销售额和毛利率,从生产和市场的角度出发,提出了一个新型的部门产品价格模式——经济部门系统的价格模型。该模型表明报告期的产品价格向量Ｐ（ｔ＋１）可以表示成两个向量的凸组合之和,其中一个是基期单位产品物耗成本ＡＴ（ｔ）Ｐ（ｔ）与报告期单位产品物耗成本ＡＴ（ｔ＋１）Ｐ（ｔ＋１）的凸组合,即Θ＾（ｔ）ＡＴ（ｔ）Ｐ（ｔ）＋Ｅ＾（ｔ）ＡＴ（ｔ＋１）Ｐ（ｔ＋１）;另一个是基期单位产品和报告期单位产品在报告期销售所获毛利δ１（ｔ＋１）和δ２（ｔ＋１）的凸组合,即Θ＾（ｔ）δ１（ｔ＋１）＋Ｅ＾（ｔ）δ２（ｔ＋１）,这里Θ＾（ｔ）≥０,Ｅ＾（ｔ）≥０,Θ＾（ｔ）＋Ｅ＾（ｔ）＝Ｉ（单位矩阵）,Ａ（ｔ）和Ａ（ｔ＋１）分别是两期的实物型投入产出表的直接消耗系数矩阵。在基期和报告期的生产技术结构一致和其它假定条件下,我们给出了该系统稳定的四个充分必要条件。最后考察了一个特例,提出了临界平均工资率ＲＣ的概念,证明了如果全社会平均工资率Ｒ＜ＲＣ,则该价格系统是稳定的。     

Rolling-induced microstructure change in Zr_(65)Al_(7.5)Ni_(10)Cu_(12.5)Ag_5 bulk metallic glass

The microstructures and free-volume evolutions of as-cast and pre-annealed Zr65Al7.5Ni10Cu12.5Ag5 bulk metallic glasses during rolling deformation have been investigated. No phase transformation is detected in the as-cast/rolled specimen. However,the structural stability of the glass against plastic deformation is worse after pre-annealing,indicated by nanocrystallization in preannealed/rolled specimens with large deformation degrees. Moreover,with increasing deformation degree,the free-volume content in a ...     

A New Method with High Confidence for Validation of Computer Simulation Models of Flight Systems

Computer simulation models may by used to gain further information about missile performance variability. Model validation is an important aspect of the test program for a missile system. Validation provides a basis for confidence in the model's results and is a necessary step if the model is to be used to draw inference about the behavior of the real missile. This paper is a review of methods useful for validation of computer simulation models of missile systems and provides a new method with high degree of confidence for validation of computer simulation models of missile systems. Some examples of the use of the new method in validating computer simulation models are given.     

吉赫兹横电磁波传输室连接头的优化设计

吉赫兹横电磁波(GTEM)传输室在电磁兼容测试领域应用广泛。GTEM传输室过渡连接头对GTEM传输室性能的影响较大。过渡连接头连接同轴传输线与GTEM传输室主体,是从圆形同轴传输线过渡到矩形同轴线的转换部件。如果过渡连接头处存在结构不连续,使其特性阻抗与GTEM传输室不匹配,将会引起电磁波反射和激发高次模现象,降低传输室的传输性能。根据GTEM传输室的技术要求,以传输系统阻抗连续为原则,对过渡接头内导体外表面和外导体内表面的形状进行同时设计,使内导体外表面与外导体内表面光滑过渡,过渡接头的特性阻抗与系统匹配。对前后端分别与标准同轴线和斧形件相连接部位进行结合设计,保证连接表面光滑,尽量降低突变。根据设计计算数据,通过设计软件SolidWorks对过渡接头构造精确三维模型。将三维模型导入电磁软件HFSS进行仿真测试。这样,对保证过渡接头特性阻抗恒定提供了一种有效的设计方法;可以将构建的数学模型直接导入电磁仿真软件,以便进一步分析;也可以将内、外导体三维结构数模导入数控机床加工,保证内外导体表面的精度要求。     

船舶运输系统分析的若干问题与方法

船舶运输是一个复杂的系统工程。船舶运输系统分析的有关内容和方法,是水运部门实际工作者和研究人员经常思考的问题。作者在本文中将研究工作中碰到的若干问题与方法作了一些整理和讨论,谈了一些粗浅的看法,供感兴趣的同行参考。     

Graft Modification of N,N''''-methylene- bisacrylamide onto Silk in the Presence of Air

The graft modification of N, N'-methylene-bisacrylamide (NNMBAA) onto silk using eerie ammonium sulfate, potassium persulfate, ammonium persulfate and 2, 2-azobis (isobutyronitrile) as the initiators has been studied in the presence of air. To establish reaction conditions for the graft modification of NNMBAA onto silk, the effect of different variables such as the initiator concentration, monomer concentration, acetic acid concentration, time of polymerization, reaction temperature and liquor ratio (fabric: liq.) have been studied. The optimum grafting conditions were found. As evidence of grafting, analyses of amino acid composition and alkali solubility have been carried out. Grafting caused changes in amino acid composition and alkali solubility of silk. The observation has been explained in relation to structural changes in the grafted silk.