详细化学反应机理对预混丙烷钝体熄火模拟影响

航空发动机熄火预测是重要关键问题之一，湍流和化学反应的非线性相互作用使预测非常困难。本文采用大涡模拟（LES）对湍流进行高精度模拟，采用概率密度函数输运方程湍流燃烧模型（TPDF）耦合JL4、Z66和H73三种化学反应机理，对预混丙烷钝体熄火现象和规律进行研究。JL4的反应机理最简单，反应释热快，局部放热高，火焰宽度大，火焰两侧温度梯度大，燃烧更加趋于稳定，无法模拟出熄火状态。H73机理绝热火焰温度低，火焰温度低，回流区中部OH含量高；在近熄火状态，大量CO被氧化，释放热量过高导致无法模拟出熄火现象。Z66机理可以模拟出火焰正常状态，在低当量比下也可以模拟出熄火状态。本文算例中，局部Da数大于1的区域超过35%则会发生熄火。     

反推力装置运动学与动力学仿真

为了研究叶栅式反推力装置各部件在工作过程中的运动学与动力学特性,根据机构运动原理对反推力装置进行简化并建立了运动学与动力学数学模型。以滑动整流罩位移与阻流门所受气动负荷为输入进行运动学与动力学仿真,得到了反推力装置各部件的位移、速度及受力特性曲线,并对比分析了在不同尺寸参数下各部件特征点的运动轨迹和反推力装置负载力变化。结果表明:运动学及动力学仿真结果与工程实际相符；反推力装置机构参数选择不合理时,各设计点会发生干涉现象并导致机构无法运动;机构参数变化对负载力最大值影响尤为突出,在阻流门AC段长度值增大6%,阻流门CB段长度值减小9%的情况下,负载力正向最大值将增大19.53%,负向最大值增大12.67%。研究方法及研究结果可为反推力装置运动学及动力学分析,以及为反推力装置机构优化设计提供参考。      

Review and propositions for the sliding/impact wear behavior in a contact interface

A thermal-solid-liquid complex operational environment induces structural interface developing a typical coupling sliding/impact wear behavior. It results in contact damage until systems fail, which may cause significant economic losses and catastrophic consequences. The key point of solving this problem is to reveal the coupling damage mechanism of the sliding/impact behavior in typical systems and life characterization under a complicate evolving environment. This has been a hot topic in the area of mechanical reliability. The main work in this paper can be concluded as follows. Firstly, the main industries in which the “sliding/impact behavior” takes place have been introduced. Then, existing studies on the wear mechanism and degree analysis are presented, which includes surface morphology analysis, wear debris analysis, and wear degree measurement. Meanwhile, existing problems in theoretical modeling and experiments in current research are summarized, so as to point out a bright direction for future research on wear prediction. They include interface contact modeling, mathematic coupling mechanism modeling, wear equation establishment, and wear life characterization, which can provide some new ideas for improving the existing studies on the sliding/impact wear behavior.     

年薪制与国有企业经营者激励机制的研究

中国加入WTO后 ,市场化改革将逐步深入 ,完善国有企业经营者激励机制显得尤为紧迫。目前国有企业普遍推行的年薪制在实施方案上存在明显缺陷 ,必须加以改进和完善 ,而整个企业体制改革的不到位 ,也制约着经营者激励机制的形成 ,因此要尽快突破体制上存在的主要障碍。     

中小外贸企业经营机制创新分析

经营机制创新是中小型外贸企业摆脱困境的必由之路。针对目前面临的主要问题，从外部环境及企业自身经营机制缺陷方面对中小型外贸企业生存环境进行分析，并从实现经营机制创新角度探讨改善现状的方法，力图找出中小型外贸企业经营机制创新的突破点。     

论我国公民对政府监督机制的优化

公民对政府的监督是行政监督体系的重要组成部分，它主要包括公民决定政府领导人的去留，举报、检举政府违法行为和进行集体利益表达三种形式。然而，我国目前这三种形式还存在不少问题。扩大和保障公民的民主权利，健全公民的信访举报制度，完善公民的集体利益表达机制，是优化我国公民对政府监督的主要制度措施。     

风量与风机的安全运行

本文阐明了离心式通风机在通风除尘(或排毒净化)系统中的作用,以及离心式通风机产生风压.风量的工作工程,从而引出风机的性能参数风量L、风压P、功率N、效率η等.文章突出地论述了风量对风压、功率、效率的影响;详尽地分析了离心式通风机的性能曲线,特别是N—L曲线;根据性能曲线分析得知,风量L为零(L=0)时,风消耗的功率N最小.从而得出结论;系统中的离心式通风机必须是在关闭状态下启动,以确保通风机的安全运行.     

拓宽周转齿轮系的应用

本文为拓宽创新设计机构的思路,扼要地介绍了一种利用空间周转轮系,实观机械手臂的公转与自转动作要求的机构运动分析、设计方案及结构参考图。     

Broad-band spectral properties of accreting X-ray binary pulsars

Broad-band spectra of accreting X-ray binary pulsars can be fitted by a phenomenological model composed of a power law with a high energy rollover above 10 keV, plus a blackbody component with a temperature of few hundred eV. While, at least qualitatively, the hard tail can be explained in terms of (inverse) Compton scattering, the origin of the soft component cannot find a unique explanation. Recently, a qualitative picture able to explain the overall broad-band spectrum of luminous X-ray pulsars was carried out by taking into account the effect of bulk Comptonization in the accretion column. After a review of these recent theoretical developments, I will present a case study of how different modeling of the continuum affect broad features, in particular the cyclotron resonance features in Vela X-1.     

空间实验室大面积太阳电池阵技术研究

介绍了空间实验室大面积太阳电池阵的方案构型，并进行了模态分析、热结构耦合分析和动力学仿真分析。生产出了全尺寸的集成演示样机，进行了展开试验、主展开机构的模态试验，以及半刚性太阳电池板和二自由度驱动机构的振动试验。计算和试验结果表明，技术方案是可行的。