对高温超导层状特性的解释

基于高温超导材料结构的准二维性,建立了高温超导的层状理论,得到了高温超导材料的临界温度Tc与Cu-O面数l间的关系,指出高物质密度N_i~0和高电子密度N_e~0的超导材料可能有更高的Tc。     

Alternatives for defense in the Post‐Soviet World: A guide for economists to the U.S. debate

The defense establishments of all major powers are changing to reflect changes in the foundations of national security strategy and resource allocation. The authors believe economists should play an active role in formulating these changes and offer an orientation to the U.S. debate, presenting three major alternatives: the “Base Force” (Bush Administration), Mr. Aspin's Force “C,” and the “Low” Alternative (Prof. Kaufmann and Dr. Steinbruner). These alternatives are compared using first‐order measures of capabilities, budgets and risk. Budgetary estimates are based on newly‐developed analytical tools.     

The impact of military spending cutbacks on economic activity in an incentive‐wage two‐sector aggregative economy∗

We examine the theoretical outcomes of disarmament on economic activity in a two‐sector model of endogenous equilibrium unemployment rate. Three main shocks are analyzed: Exogenous cutbacks in military spending on the capital good and employment, and a reduction in public sector debt. The first shock is contractionary for equilibrium employment if the capital‐goods producing sector is relatively labour‐intensive but expansionary under the alternative factor intensity assumption. The second shock is contractionary for employment under either relative factor intensity assumption. If Ricardian equivalence fails, a reduction in public sector debt is likely to expand long‐term employment (JEL E24).     

DETERMINING THE DEFENCE INDUSTRIAL BASE

This paper models the determination of the defence industrial base – the number of different military systems a country decides to maintain. High R&D costs means that few countries can afford to produce major weapons systems and the producers also import systems. Non‐producers rely on imports and we assume their demand is driven by regional arms races. Military capability is determined by the number of systems and the quantity and quality of each. We examine how the defence industrial base is influenced by military expenditures, R&D costs, export controls, the nature of regional arms races and a variety of other factors.     

一类具有阶段结构和潜伏期时滞的SEI模型的全局动力学性态

研究一类具有潜伏期时滞、阶段结构和标准发生率的SEI模型,利用比较定理和单调迭代的方法,分别得到无病平衡点和地方病平衡点全局吸引的充分条件．     

再生冷却通道结构参数对碳氢燃料流量分配影响

以液体火箭发动机再生冷却技术为背景,采用数值模拟方法对Z-type型并联通道流量分配特性进行研究,分析了通道数、通道截面形状及入口汇流结构对流量分配特性的影响。研究结果表明:在冷却通道总流通面积相同的情况下,随着再生冷却系统通道数的增加,流量分配不均匀度系数从2.59%降低至0.5%,相同流通面积下增加通道数可以有效提高流量分配的均匀程度。通道截面形状对流量分配不均匀度系数影响不大,其影响主要表现在通道内部流体速度分布及换热面积上。从换热效果看,梯形截面构型要优于矩形构型。入口汇流结构倾斜角有利于流量的均匀性分布。该研究对于再生冷却通道结构设计具有一定参考价值。     

优化教员系统年龄结构的系统动力学模型

为了加强高等院校师资队伍建设,本文用系统动力学(System Dynamic,简称SD)的方法建立了某校师资队伍分析、预测模型,对其年龄结构进行了模拟分析,提出了今后几十年中师资队伍出现的问题及应采取的策略.     

基于VFD滤波器的导航信道模拟器动态时延模拟方法*

针对卫星导航信道模拟器信号仿真中,传统伪距多普勒模拟方法瞬时控制精度差、滤波器资源占用较大的不足,提出了基于拉格朗日插值延迟滤波器及Farrow结构实现的伪距多普勒模拟方法。在分析信道模拟器系统架构的基础上,建立了多普勒模拟方法的模型,包括延时计算模块和可变延迟滤波器两部分。与多速率采样数字延迟滤波器方法比较,该方法滤波器系数个数约为后者的0.2%,并且改变时延特性时,仅需更新1个参数。信道模拟器实测数据结果表明使用该方法伪码多普勒模拟精度可以达到0.1mHz。     

无线网络控制系统一致性研究

通过构建李雅普诺夫函数,对具有不同拓扑结构的无线网络控制系统的一致性问题进行了研究。利用网络结构的邻接矩阵对网络拓扑结构进行描述,同时构造系统的延迟矩阵,结合复杂网络理论中的聚类系数、耦合强度的概念,对系统进行建模。针对复杂网络中常用的两种结构,构建不同的邻接矩阵和延迟矩阵,利用线性矩阵不等式的方法,给出使系统稳定的一般性条件。最后仿真结果验证了方法的有效性。     

C~4ISR系统结构时效性的仿真评估

时效性是评价C4ISR系统结构优劣的重要标准。为了支撑C4ISR系统结构的分析评估与优化设计,提出了系统结构时效性的评估指标体系和指标评估模型,基于Agent建模方法建立了情报获取、情报处理、决策控制和响应执行等系统结构单元的仿真模型,设计并实现了C4ISR系统结构仿真评估软件。开展了三类仿真实验,分析了影响系统结构时效性的因素,比较了不同类型系统结构的优劣,验证了此方法的有效性。