315 resultados para 179-1106


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利用能量为 16 4— 180MeV的3 5Cl束流 ,通过14 9Sm(3 5Cl,p4n)反应研究了179Pt的高自旋态能级结构 .进行了γ射线的激发函数、X γ和γ γ t符合测量 ,建立了基于 1 2 -[5 2 1],5 2 -[5 12 ]和7 2 + [6 33]组态的 3个转动带 .实验上观测到 1 2 -[5 2 1]带在ω =0 2 7MeV附近顺排角动量突然增大 ,且 7 2 + [6 33]带具有较大的旋称劈裂 .通过比较奇APt同位素和179Pt的同中子素能级结构的系统性 ,对相关现象进行了分析和讨论 .

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利用能量为 16 4— 180MeV的 3 5Cl束流 ,通过重离子核反应 14 9Sm(3 5Cl ,5n)研究了 179Au的高自旋态能级结构 .实验进行了γ射线的激发函数、X γ和γ γ t符合测量 .基于对实验测量结果的分析 ,首次建立了 179Au的 1 2 [6 6 0 ](πi13 2 )转动带 .结合已有的实验数据 ,着重讨论了奇AAu核中1 2 [6 6 0 ](πi13 2 )转动带的带头激发能随中子数的变化

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Finite-fringe interferograms produced for axisymmetric shock wave flows are analyzed by Fourier transform fringe analysis and an Abel inversion method to produce density field data for the validation of numerical models. For the Abel inversion process, we use basis functions to model phase data from axially-symmetric shock wave structure. Steady and unsteady flow problems are studied, and compared with numerical simulations. Good agreement between theoretical and experimental results is obtained when one set of basis functions is used during the inversion process, but the shock front is smeared when another is used. This is because each function in the second set of basis functions is infinitely differentiable, making them poorly-suited to the modelling of a step function as is required in the representation of a shock wave.

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Supersonic combustion of thermally cracked kerosene was experimentally investigated in two model supersonic combustors with different entry cross-section areas. Effects of entry static pressure, entry Mach number, combustor entry geometry, and injection scheme on combustor performance were systematically investigated and discussed based on the measured static pressure distribution and specific thrust increment due to combustion. In addition, the methodology for characterizing flow rate and composition of cracked kerosene was detailed. Using a pulsed Schlieren system, the interaction of supercritical and cracked kerosene jet plumes with a Mach 2.5 crossflow was also visualized at different injection temperatures. The present experimental results suggest that the use of a higher combustor entry Mach number as well as a larger combustor duct height would suppress the boundary layer separation near the combustor entrance and avoid the problem of inlet un- start.

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本文介绍了太阳湍流发电机问题的双尺度平均场电动力学分析方法以及有关太阳发电机问题的研究结果:α,β效应及各种发电机模型。总结分析了现阶段太阳湍流发电机问题在观测和理论方面的主要困难。对其他的太阳发电机理论也进行了简要介绍。

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<正> 一、金属材料表面改性的经济意义和离子注入技术 巨大的经济意义始终是开展材料研究,提高金属材料表面抗磨、抗疲劳、耐腐蚀等性能的主要推动力。如在摩擦、磨损方面,1964年英国教育科研国务大臣邀请全国著名摩擦、润滑工程专家对全国进行了普查,并于1966年发表报告指出,英国如能运用摩擦学知识,每年可节约5.15亿英镑,美国国会在1975年度报告中也指出:由于摩擦、磨损造成的经济损失据估计约值1000亿美元,其中200亿是材料费,其它如零件表面的疲劳,腐蚀也是材料

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为了实际使用更方便,我们提出了LJD状态方程的一个简便公式。这个简化了的表达式是基于LJD理论在θ从10到290和τ从0.3到1.0范围内的数值结果得来的,而该理论中所用的分子间相互作用势是6-exp(α=13)势。用这式子计算的结果与数值结果相比最大偏差约为10%,而对爆轰产物所涉及的范围则在6%以内。

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Microcracks can have a strong influence on the elastic and fracture mechanical properties of rocks if they are numerous, or if they are orientated in unfavourable directions in anisotropic rocks in particular. This paper presents results from a great number of mechanical tests on Stripa granite containing various amounts of microcracks. Variations in the microcrack density were obtained by shock-heating the rock at different temperatures in the range 100–600°C for 3 h.

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大面积薄膜的组分和厚度分布是实际工艺中最为关心的问题之一.利用实验和直接模拟Monte Carlo(DSMC)方法,分别研究了双电子束和三电子束物理气相沉积(EBPVD)中,钇和钛蒸气原子的三维低密度、非平衡射流,获得了它们在100和150mm单晶硅基片表面的沉积厚度和组分的分布.DSMC结果与钇和钛的蒸发速率的石英晶振探头原位测量值,沉积薄膜厚度分布的台阶仪和Rutherford背散射仪的测量数据,沉积薄膜组分分布的Rutherford背散射仪和电感耦合等离子体原子发射光谱仪测量值,均相符甚好.这表明通过DSMC方法与精细测量相结合,可在原子水平上实现EBPVD输运工艺的定量预测和设计。

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采用改进的BP神经网络模型模拟水力旋流器的油水分离过程.根据水力旋流器的实际运行条件,确定旋流器模型设计中的优化神经网络结构,将遗传算法用于优化三层BP神经网络的初始权重,采用PRP共轭梯度法优化BP算法.结果表明,采用人工神经网络模型预测油水分离水力旋流器的分离性能是切实可行的,它能成功地模拟旋流器的分离过程,进而实现旋流器操作控制的优化.

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根据三峡升船机最新设计报告,采用有限元软件ANSYS构建了升船机系统有限元模型,包括承船厢、提升钢索、滑轮组、平衡重、厢内水体、驱动机构和刹车机构;通过数值模拟,对升船机系统进行了模态分析及动态响应研究,内容包括升船机系统的流固耦合模态及其在各种工况(起动、刹车、事故)下的动态响应和影响因素分析,如弹簧刚度、误载水深、阻尼、承船厢的位置等.计算结果表明:对于升船机这样一个复杂系统,该文所建立的有限元模型及数值算法是合理的,其结果可为升船机系统整体设计提供必要的参考.