爆炸塔内壁特征点的反射压力数值模拟

采用LS-DYNA编码,对直径2 m的爆炸塔及其缩比模型的爆炸流场进行了数值模拟,给出了塔体内壁几个特征点的反射压力曲线,并与其中两个特征点的实测压力曲线进行了对比.研究结果表明:爆炸塔宜选择椭球封头,而非传统设计通常采用的球形封头,因为球形封头击波的会聚效应更强;用LS-DYNA这类商业软件来模拟爆炸流场,网格划分需尽可能细,不然模拟结果仅具有定性参考价值。     

Inhibition of Salidroside on Salivary Gland Adenoid Cystic Carcinoma

To evaluate the role of salidroside on proliferation,apoptosis and invasiveness of salivary gland adenoid cystic carcinoma cells(SACC),immunocytochemical staining was employed to detect proliferating cell nuclear antigen(PCNA),caspase 3 and caspase 8 expression in SACC-2 cells.Modified Boyden chamber assay combined with laser confocal microscopy(LSCM) was used to evaluate the invasion and migration abilities of SACC-2 cells at different time point.Immunohistochemistry staining revealed that the expression of PCNA was significantly decreased(P0.01) after salidroside treatment.In contrast,salidroside treatment led to increased caspase 3 and caspase 8 in SACC-2 cells.Cell migration depth and number of cells that penetrated Boyden chamber were also decreased by salidroside.Salidroside potently inhibits the proliferation and simultaneously induces the apoptosis of SACC-2 cells.Migration and invasion of SACC-2 cells are also inhibited.Our data throw light on potential clinical application of salidroside to the patients with SACC.     

密封恒温分光光度法快速测定化学需氧量

建立了密封恒温消解样品,测定化学需氧量（CDDcr)的分光光度法。应用正交试验法确定了密封恒温法消解试样的最佳条件,此方法有机物的氧化率为98.33%-99.50%。CODcr值在0-800mg/mL范围内符合比耳定律。样品测定的相对标准偏差为0.39%（n=12),加标回收率为97.50%-99.56%。用该法测得的CODcr值与标准回流法所得结果一致。     

Research on the boron contamination at the p/i interface of microcrystalline silicon solar cells deposited in a single PECVD chamber

This paper studies boron contamination at the interface between the p and i layers of μ c-Si:H solar cells deposited in a single-chamber PECVD system. The boron depth profile in the i layer was measured by Secondary Ion Mass Spectroscopy. It is found that the mixed-phase μ c-Si:H materials with 40% crystalline volume fraction is easy to be affected by the residual boron in the reactor. The experimental results showed that a 500-nm thick μ c-Si:H covering layer or a 30-seconds of hydrogen plasma treatment can effectively reduce the boron contamination at the p/i interface. However, from viewpoint of cost reduction, the hydrogen plasma treatment is desirable for solar cell manufacture because the substrate is not moved during the hydrogen plasma treatment.     

北京谱仪Ⅱ带电径迹测量误差矩阵的修正

研究了北京谱仪(BES)Ⅱ带电径迹测量误差矩阵的修正,使运动学拟合TELESIS方法在BESⅡ物理数据分析中得到应用.1)在BESⅡ数据重建程序中,加入了适当的MDC重建单丝分辨率(250μm)和Q修正.2)在TELESIS程序中,放入了BESⅡ有效物质量对BESⅡ误差矩阵进行多次库仑散射和dE/dX能损效应的修正.3)在此基础上,通过J/ψ→μ⁺μ^－的数据样本分析,完成了BESⅡ24×10⁶J/ψ事例RUN-by-RUN的误差矩阵刻度,同时对BESⅡMC数据也作了相应的刻度.经上述误差矩阵修正后,BESⅡ的TELESIS可以较好地满足BESⅡ数据分析工作的要求.     

Spectroscopy of Ly-α Lines at Storage Rings by Crystal Spectrometry and Absorption Edge Technique

Crystal spectrometry and absorption edge technique have the capability to overcome the gap in accuracy between experiment and theory in the strong field domain of QED. New results are presented which indicate the capacity of these methods to measure the energies of X-rays emitted by highly charged heavy ions at modern storage rings with a precision sensitive to second order corrections to the Lambshift in H-like very heavy ions. This revised version was published online in July 2006 with corrections to the Cover Date.     

基于耦合声场建模的膨胀腔消声器声学性能分析及试验

针对圆柱形膨胀腔消声器三维建模及声学性能分析问题, 提出一种基于切比雪夫变分原理的耦合声场建模方法, 建立三维圆柱形膨胀腔消声器理论模型并搭建试验台架, 传递损失试验结果验证了理论模型的准确性. 将膨胀腔消声器内部声场分解为多个子声场, 基于子声场间压力与质点振速连续性条件, 推导声场耦合变分公式, 构建子声场拉格朗日泛函. 将子声场声压函数展开为切比雪夫-傅里叶级数形式, 通过瑞利-里兹法求解膨胀腔消声器频率、声压响应及传递损失. 计算并对比分析扩张比、扩张腔长度、进出口管偏置对膨胀腔消声器消声性能的影响. 结果表明: 扩张比增大会有效提高消声器在低频段的消声性能, 进出口管的偏置对消声器消声性能影响很小.     

Numerical study of unsteady flow and heat transfer of circular tangential direction jets flowing over the inner cylinder surface in the annular chamber

In order to understand the dynamics of vortices on heat transfer, the unsteady flow field of tangential direction jets flowing in the annular chamber is numerically investigated by scale-adaptive simulation (SAS). The jet Reynolds number is 332,000 based on the jet’s diameter and inflow velocity for a specific geometric model. The analogy theory is used to obtain the convective heat transfer coefficient distribution on the hub surface. Spectral analysis via fast Fourier transform (FFT) is used to analyze frequency information that flows inside the chamber. The proper orthogonal decomposition (POD) method is performed on the velocity field in the chamber and the convective heat transfer coefficient on the hub surface using a snapshot method. The fast Fourier transform helps find the dominant frequency of the unsteady flow in the chamber. The time sequence of velocity fields on the radial plane shows the presence of cyclic flapping of the jet. The proper orthogonal decomposition analysis indicates that the unsteady periodic flow phenomenon in the chamber and unsteady heat transfer on the hub surface are mainly related to the dynamics of the counter-rotating vortices caused by the jet.     

基于等离子体腔表面增强拉曼效应的研究

金属离子水滴与液态聚二甲基硅氧烷（PDMS）自发形成的等离子体腔作为一种新型的表面增强拉曼（SERS）基底将等离子体纳米颗粒整合到光学装置中，提高了SERS检测的实用性与可靠性，然而，与其他基底相比，对其最佳生长条件的研究很少。在此，用禁用兽药孔雀石绿（MG）作为探测分子，检验不同生长条件下等离子体腔的特性，包括生长温度和金属离子浓度，以研究等离子体腔的最佳生长条件。金属离子水溶液滴加到互不相容的液态PDMS上时，在表面张力和重力的共同作用下自发形成带开口的球形腔体。同时金属离子扩散到未固化的PDMS中并与残留的Si-H基团反应，金属离子逐渐还原成金属纳米颗粒，并随着PDMS的固化过程在腔体表面逐渐累积，最终形成等离子体腔。其不但能作为角度反射器将入射光限制在腔体中，而且可作为纳米级光子源将吸收的光散射到腔体中，这两个功能共同作用可在基底原本增强作用的基础上进一步提高对MG的拉曼增强效果。较高的生长温度在加快金属离子生长的同时也会加速PDMS的固化，以至于提前结束金属纳米粒子的生长过程。离子浓度越高，形成的金属离子颗粒越大，然而颗粒直径过大，等离子体腔表面的热点数量反而会减少，MG的拉曼增强减弱，因而，必定存在最优化的等离子体腔制备条件使基底对MG的增强效果达到最佳。设置了15，20，25和30 ℃的生长温度以及0.05，0.5，5和50 μg·mL-1的离子浓度，结果表明，在温度为25 ℃，0.5 μg·mL-1的生长条件下等离子体腔实现了对MG的最佳拉曼增强。对等离子体腔生长条件的优化，可为提高该类型基底的SERS增强效果，及可重复制备奠定基础。     

生物材料低温保存设备的研究

介绍了生物材料低温保存设备的工作过程和装置结构,并对主要部件冷却室的结构和制作原理进行了分析,同时对控制系统及冷冻速率进行讨论。