弹道导弹自由段飞行中的守恒量及其应用

从精确弹道计算所用的数学模型出发，指出了弹性在自由段飞行中的两个具有明确物理意义的运动守恒量，并给出了用发射坐标系下的运动参数求这些守恒量的简洁计算公式。这两个守恒量可作为一种简单、实用的辅助评估手段用于计算结果可信性分析以及导弹发射诸元的校验。     

Ionospheric behavior of the F2 peak parameters foF2 and hmF2 at Hainan and comparisons with IRI model predictions

Monthly median values of foF2, hmF2 and M(3000)F2 parameters, with hourly time interval resolution for the diurnal variation, obtained with DPS-4 digisonde observations at Hainan (19.4°N, 109.0°E) are used to study the low latitude ionospheric variation behavior. The observational results are compared with the International Reference Ionospheric Model (IRI) predictions. The time period coverage of the data used for the present study is from March 2002 to February 2005. Our present study showed that: (1) In general, IRI predictions using CCIR and URSI coefficients follow well the diurnal and seasonal variation patterns of the experimental values of foF2. However, CCIR foF2 and URSI foF2 IRI predictions systematically underestimate the observed results during most time period of the day, with the percentage difference ΔfoF2 (%) values changing between about −5% and −25%, whereas for a few hours around pre-sunrise, the IRI predictions generally overestimate the observational ones with ΔfoF2 (%) sometimes reaching as large as ∼30%. The agreement between the IRI results and the observational ones is better for the year 2002 than for the other years. The best agreement between the IRI results and the observational ones is obtained in summer when using URSI coefficients, with the seasonal average values of ΔfoF2 (%) being within the limits of ±10%. (2) In general, the IRI predicted hmF2 values using CCIR M(3000)F2 option shows a poor agreement with the observational results. However, when using the measured M(3000)F2 as input, the diurnal variation pattern of hmF2 given by IRI2001 has a much better agreement with the observational one with the detailed fine structures including the pre-sunrise and post-sunset peaks reproduced reasonably well. The agreement between the IRI predicted hmF2 values using CCIR M(30,000)F2 option and the observational ones is worst for the afternoon to post-midnight hours for the high solar activity year 2002. During daytime hours the agreement between the hmF2 values obtained with CCIR M(30,000)F2 option and the observational ones is best for summer season. The discrepancy between the observational hmF2 and that obtained with CCIR M(30,000)F2 option stem from the CCIR M(3000)F2 model, which does not produce the small scale structures observed in the measured M(3000)F2.     

What Determines the Composition of SEPs in Gradual Events?

Gradual solar energetic particle (SEP) events are evidently accelerated by coronal/interplanetary shocks driven by coronal mass ejections. This talk addresses the different factors which determine the composition of the accelerated ions. The first factor is the set of available seed populations including the solar wind core and suprathermal tail, remnant impulsive events from preceding solar flares, and remnant gradual events. The second factor is the fractionation of the seed ions by the injection process, that is, what fraction of the ions are extracted by the shock to participate in diffusive shock acceleration. Injection is a controversial topic since it depends on the detailed electromagnetic structure of the shock transition and the transport of ions in these structured fields, both of which are not well understood or determined theoretically. The third factor is fractionation during the acceleration process, due to the dependence of ion transport in the turbulent electromagnetic fields adjacent to the shock on the mass/charge ratio. Of crucial importance in the last two factors is the magnetic obliquity of the shock. The form of the proton-excited hydromagnetic wave spectrum is also important. Finally, more subtle effects on ion composition arise from the superposition of ion contributions over the time history of the shock along the observer’s magnetic flux tube, and the sequence of flux tubes sampled by the observer.     

液相色谱仪故障分析与处理

简述了液相色谱仪工作原理，对常见故障进行了分析，并给出了处理方法。     

Phase coherence of MHD waves in the solar wind

Large amplitude MHD waves are commonly found in the solar wind. Nonlinear interactions between the MHD waves are likely to produce finite correlation among the wave phases. For discussions of various transport processes of energetic particles, it is fundamentally important to determine whether the wave phases are randomly distributed (as assumed in quasi-linear theories) or they have a finite coherence. Using a method based on a surrogate data technique and a fractal analysis, we analyzed Geotail magnetic field data (provided by S. Kokubun and T. Nagai through DARTS at the Institute of Space and Astronautical Science) to evaluate the phase coherence among the MHD waves in the earth's foreshock region. The correlation of wave phases does exist, indicating that the nonlinear interactions between the waves is in progress. This revised version was published online in August 2006 with corrections to the Cover Date.     

费率受制于位相半马氏过程的风险模型

对带马氏链的线性和非线性系统，经过众多学者近20多年的努力，已取得一系列重要成果。然而，由于马氏链状态逗留时间服从负指数分布，使得这些成果在应用中有很大的局限性。本文首先探讨了位相半马氏过程的性质，然后以位相半马氏过程代替马氏过程，研究风险模型的相关问题，取得了与马氏链相同的研究成果，从而说明了位相半马氏过程在克服由马氏过程带来的局限性中的作用。     

共析钢的相变超塑性扩散连接

根据高温扩散和空洞蠕变闭合理论，在恒温超塑性扩散连接基础上建立相变超塑性扩散连接数学模型，可确定各工艺参数，诸如循环上限温度、压力、循环次数以及升、降温速率等对连接的影响，作为选择合适工艺参数的依据。经过对T8共析钢相变超塑性扩散连接试验研究，证明该理论模型与试验结果吻合较好。     

混气电解加工中两相流音速及阻塞机理研究

着重分析研究气液两相流音速特性及其阻塞机理。通过测量由小药量电雷管爆炸而产生的压力波传播速度，然后修正到音速。试验结果表明，气液两相流音速与气泡率、当地压力及其流型有关。由于气液混合物强烈的压缩性，混气电解加工间隙中易于出现类似可压缩气体的阻塞现象。     

离心泵叶轮内含颗粒的幂律流体的密相两相湍流研究

阐述了幂律流体控制方程的特点，首先对单相的幂律流体与密相液固两相流进行了计算，计算结果与实验数据吻合较好。其次对泵离心叶轮内的含颗粒的幂律流体的两相流动进行了计算，从进口到出口，幂律流体的速度是减小的，压力随半径增大逐渐升高，而且压力面上的压力大于吸力面上的压力。吸力面上的颗粒拟温度小于压力面上的颗粒拟温度，而且靠近壁面处的大于叶道中的。最后比较了液固两相流与含颗粒的幂律流体的两相流的流动。流体相的紊动能有一定的差别，而且颗粒拟温度也有较大差别。     

低频声波对水雾消散作用的实验研究

作者考查了低频声波(<50Hz)对于水雾消散的作用。通过建立声波消雾实验装置,测定了在水雾消散过程中,雾室内的声场分布、温度、消雾时间、雾滴谱的变化过程。实验结果表明声波作用对于水雾的消散具有明显的作用。并且,消雾的效果随着作用声波的频率和声压级(SPL)呈规律性的变化趋势。较低频率和较高声强的声波作用更有利于水雾的消散,在消雾的过程中温度起伏不大。而声致凝聚是声波消雾的主要因素之一。