基于hp自适应伪谱法的可调推力最优离轨研究

根据不同最优化指标要求,利用hp自适应伪谱法,对比分析了固定推力和可调推力制动离轨时的参数变化情况。通过研究发现,以燃料最省为优化指标,采用可调推力制动时,飞行器过渡段飞行时间更长,燃料消耗相对较小;而在时间最短指标要求下,可调推力制动虽消耗大量燃料,但能大大缩短过渡段飞行时间,有利于航天器在执行紧急任务时的快速返回。     

试析马克思理论体系的两个思想资源

除了常说的三大理论来源以外,马克思的理论体系的形成还有很多丰富的思想资源,其中,基督教和<圣经>传统、古希腊神话和西方文学作品对马克思科学世界观、人生观、价值观的形成产生了深刻影响,马克思对他们采取了批判的借鉴的态度,从中汲取了丰富的营养,成为马克思理论体系重要的思想资源.     

西部农村金融发展中存在的问题及对策

西部地区在新农村建设过程中普遍面临金融支农资金短缺、金融服务体系边缘化、民间金融缺乏保护、金融改革严重滞后、金融创新不足等问题，现存的城乡二元金融体制已经成为阻碍西部地区新农村建设的重要因素。文章提出我国农村金融体制的创新发展，关键在于通过制度创新重构欠发达区域农村金融体系，强化金融服务“三农”的功能，增强其对新农村建设的支持力度，辅之以创新“农业经营项目”贷款抵押、信用担保与信贷投放机制，多管齐下，全方位解决农村金融发展中遇到的各种问题，最终使我国金融体系真正发挥支持新农村建设的应有作用。     

GaAs的光学常数的计算

为深入认识GaAs的光学性质,采用从头算法计算其电子结构,并依据线性响应理论计算出它的复介电常数,进而得到复折射率,反射系数,吸收系数等光学常数。     

多喷管液体火箭动力系统尾焰冲击特性研究

为深入研究多喷管液体火箭动力系统尾焰冲击特性,以由多喷管液体火箭动力系统构成的发射平台为研究对象,采用三维N-S方程描述尾焰冲击流动过程,采用Realizable k-ε湍流模型封闭流动方程组,并运用压力的隐式算子分割(PISO)算法进行求解,得到了火箭动力系统尾焰对不同导流面导流槽的冲击流场参数。结果表明:导流面上受冲击影响最大的是沿喷管轴线方向的正冲击区域,且助推器尾焰对导流面的冲击效应相比于芯级更加强烈。锥形导流面对多喷管动力系统尾焰具有很好的引射和导流作用,相比于楔形导流面更能降低尾焰的冲击影响,但会在流场中形成漩涡并卷吸高温燃气,可能对发射系统造成破坏,需要增加相应的热防护措施。     

无网格方法中含参数指数权函数的研究

选择合适的权函数及相应的影响半径是无网格方法中很重要的问题,在引入数值紧支域概念的基础上分析了含参数的指数权函数中参数的选取范围,综合考虑计算效率和精度后给出了参数的选取原则,并讨论了在特定的参数下的最优半径以及不同参数对最优半径的影响.     

电大尺寸天线罩电磁特性高效数值仿真技术

针对电大尺寸天线罩电磁特性，分析研究了快速求解表面积分方程的多层快速多极子算法及其改进技术。构造了具有良好矩阵性态的积分方程形式，提出加速迭代求解的并行预条件技术，利用分组稀疏化方式构造预条件矩阵，显著降低了迭代求解次数。采用快速球谐展开技术对聚合和配置因子项进行压缩，将其存储量降低了2/3。通过数值算例验证了方法的精确性和高效性，并实现了大型带罩阵列天线辐射特性的仿真分析。     

构筑内陆开放型人才高地的对策研究

建设内陆开放型人才高地是中原经济区建设的一个重要任务.先进城市的人才建设经验主要有:引进与培养相结合、培养机制多元化、发挥高校的核心作用和理论联系实际.河南省的人才高地建设应由政府主导,完善人才引进机制；扶持重点产业,鼓励企业培养和吸引创新人才；改革高等教育,着力培养大批高素质的开放型人才；联系实际,实现人才本土化和国际化相结合.     

Experimental investigation on aero-heating of rudder shaft within laminar/turbulent hypersonic boundary layers

The aero-heating of the rudder shaft region of a hypersonic vehicle is very harsh, as the peak heat flux in this region can be even higher than that at the stagnation point. Therefore, studying the aero-heating of the rudder shaft is of great significance for designing the thermal protection system of the hypersonic vehicle. In the wind tunnel test of the aero-heating effect, we find that with the increase of the angle of attack of the lifting body model, the increasement of the heat flux of the rudder shaft is larger under laminar flow conditions than that under turbulent flow conditions. To understand this, we design a wind tunnel experiment to study the effect of laminar/turbulent hypersonic boundary layers on the heat flux of the rudder shaft under the same wind tunnel freestream conditions. The experiment is carried out in the ?2 m shock tunnel(FD-14 A) affiliated to the China Aerodynamics Research and Development Center(CARDC). The laminar boundary layer on the model is triggered to a turbulent one by using vortex generators, which are 2 mm-high diamonds. The aero-heating of the rudder shaft(with the rudder) and the protuberance(without the rudder) are studied in both hypersonic laminar and turbulent boundary layers under the same freestream condition. The nominal Mach numbers are 10 and 12, and the unit Reynolds numbers are2.4 × 10~6 m~(-1) and 2.1 × 10~6 m-1. The angle of attack of the model is 20°, and the deflection angle of the rudder and the protuberance is 10°. The heat flux on the model surface is measured by thin film heat flux sensors, and the heat flux distribution along the center line of the lifting body model suggests that forced transition is achieved in the upstream of the rudder. The test results of the rudder shaft and the protuberance show that the heat flux of the rudder shaft is lower in the turbulent flow than that in the laminar flow, but the heat flux of the protuberance is the other way around,i.e., lower in the laminar flow than in the turbulent flow. The wind tunnel test results is also validated by numerical simulations. Our analysis suggests that this phenomenon is due to the difference of boundary layer velocities caused by different thickness of boundary layer between laminar and turbulent flows, as well as the restricted flow within the rudder gap. When the turbulent boundary layer is more than three times thicker than that of the laminar boundary layer, the heat flux of the rudder shaft under the laminar flow condition is higher than that under the turbulent flow condition. Discovery of this phenomenon has great importance for guiding the design of the thermal protection system for the rudder shaft of hypersonic vehicles.     

基于变质性产品及模糊需求情况下的最优订购问题

将市场需求和变质率同时看成模糊数,并将物品的销售价格分成两部分来进行处理:没有损耗的产品以一种较高价格出售,有部分损耗的产品则按相对成本价较低的价格出售,建立使得平均利润最大的模糊库存模型,并利用三角模糊数、符号距离法进行处理,得出满足条件的最优订购批量.最后,通过分析算例来验证模糊库存模型比经典的库存模型更有效.