羧基化聚苯乙烯微球的制备及其在干片扩散中的应用

为提高干片检测的效率与准确性,利用自制的羧基化聚苯乙烯微球制成CRP干片,探究了堆积方式和粒径对扩散的影响.最终确定了最密堆积的排列方式、总结拟合出了粒径与扩散时间之间的经验回归方程,并筛选出适合应用于干片扩散的微球粒径最小为4.0μm.通过改变溶剂、引发剂浓度、分散剂浓度调控聚苯乙烯微球粒径并探究其原因.     

污染土壤的物化修复治理技术研究

污染土壤的修复治理过程中,物化技术以其快速高效的特点成为国内外研究的热点。本文通过对工程措施、玻璃化技术、热修复、电动力修复、光化学降解、化学淋洗、化学固定/稳定化、化学氧化以及联合修复等常见土壤物化治理技术进行了分析,探讨了各种工艺技术的性能及优缺点,旨在为我国土壤污染修复治理技术的选择提供参考。     

污染土壤的物化修复治理技术

污染土壤的修复治理过程中,物化技术以其快速高效的特点成为国内外研究的热点。本文通过对工程措施、玻璃化技术、热修复、电动力修复、光化学降解、化学淋洗、化学固定/稳定化、化学氧化以及联合修复等常见土壤物化治理技术的分析,探讨了各种工艺技术的性能及优缺点,旨在为我国土壤污染修复治理技术的选择提供参考。     

用传递矩阵法预测单层或多层微孔板的吸声性能

提出用实验测得含不同孔径孔的微孔板声阻抗率来预测由其形成的单层或多层微孔板的吸声特性，并用传递矩阵法来预测该微孔板的各种组合结构的整体吸声性能。采用该方法获得的微孔板吸声性能曲线与实测结果相当接近，能较好地预测各种组合微孔板的吸声性能。表明传递矩阵法是预测较复杂形式微孔板结构吸声性能的一种有效的方法。     

A Geometry Model for Tortuosity of Streamtubes in Porous Media with Spherical Particles

A geometry model for tortuosity of tortuous streamtubes in porous media with spherical particles is proposed based on the assumption that some particles in a porous medium are unrestrictedly overlapped and hence of different configurations. The proposed model is a function of porosity with no empirical constant imposed on it.The model predictions are found to be in good agreement with the available experimental data.     

Lagrangian analysis of the formation and mass transport of compressible vortex rings generated by a shock tube

In order to understand the mass transport and the dynamic genesis associated with a compressible vortex formation,a dynamic analysis of compressible vortex rings (CVRs) generated by shock tubes by using the framework of Lagrangiancoherent structures (LCSs) and finite-time Lyapunov exponents field (FTLE) is performed. Numerical calculation is performed to simulate the evolution of CVRs generated by shock tubes with 70 mm, 100 mm, and 165 mm of the driver sectionat the circumstances of pressure ratio = 3. The formation of CVRs is studied according to FTLE fields. The mass transportduring the formation is obviously seen by the material manifold reveled by FTLE fields. A non-universal formation numberfor the three CVRs is obtained. Then the elliptic LCSs is implemented on three CVRs. Fluid particles separated by ellipticLCSs and ridges of FTLE are traced back to t = 0 to identify the fluid that eventually forms the CVRs. The elliptic LCSsencompass around 60% fluid material of the advected bulk but contain the majority of the circulation of the ring. The otherparts of the ring carrying almost zero circulation advect along with the ring. Combining the ridges of FTLE and the ellipticLCS, the whole CVR can be divided into three distinct dynamic parts: vortex part, entrainment part, and advected part. Inaddition, a criterion based on the vortex part formation is suggested to identify the formation number of CVRs.     

Y2O3∶C陶瓷的发光性能

采用传统陶瓷制备工艺制备了C掺杂的Y₂O₃多晶陶瓷;研究了Y₂O₃∶C陶瓷的光谱性能,发现在403 nm有明显的发射峰。通过对其激发光谱的研究,表明它们是由F⁺和F色心造成的。本文还研究了Y₂O₃∶C陶瓷的热释光和光释光性能。用2个指数衰变函数拟合光衰变曲线得到的衰变时间常数τ₁=(4.66±0.27)s,τ₂=(23.31±1.03) s。     

湍流信号分析中小波基的对比和选取

采用小波分析处理湍流脉动信号时,不同的小波基往往会带来不同的分析结果.为了尽可能准确地提取湍流流动的多尺度特征,研究并建立湍流信号处理中适宜小波基选取的合理方法是十分必要的.基于湍流时频特性,结合信息熵理论,建立了以品质因数和特征谱熵值为评价指标的小波基选取方法.以计算分析三组不同湍流信号的小波基为例,结果进一步验证了...     

Preliminary shielding analysis in support of the CSNS target station shutter neutron beam stop design

The construction of China Spallation Neutron Source (CSNS) has been initiated in Dongguan, Guangdong, China. Thus a detailed radiation transport analysis of the shutter neutron beam stop is of vital importance. The analyses are performed using the coupled Monte Carlo and multi-dimensional discrete ordinates method. The target of calculations is to optimize the neutron beamline shielding design to guarantee personal safety and minimize cost. Successful elimination of the primary ray effects via the two-dimensional uncollided flux and the first collision source methodology is also illustrated. Two-dimensional dose distribution is calculated. The dose at the end of the neutron beam line is less than 2.5 μSv/h. The models have ensured that the doses received by the hall staff members are below the standard limit required.     

基于动态全息的面内微振动测量系统

为了实时测量高频、微小面内振动,利用硅酸铋（BSO）晶体的光折变特性搭建了基于动态全息的面内微振动测量系统。通过粗糙表面的散射信号光携带面内振动信息,与参考光在晶体内干涉形成动态全息并实时衍射,参考光的衍射光和信号光的透射光之间形成新的干涉,通过光电探测器对干涉信号进行解时域或频域的探测,即可得到振动信息。以剪切式压电陶瓷驱动的散射片为被测物,实验测量了0.5～240 kHz的亚微米量级的面内振动。