BEPCⅡ冲击磁铁的设计和样机研制

由于BEPCⅡ储存环注入系统对冲击磁铁的设计要求比较高，国际上现有的两种低束流阻抗的冲击磁铁方案都不能完全满足其要求. 本文提出的一种新型冲击磁铁方案解决了BEPCⅡ冲击磁铁的设计难题，并且通过样机的成功研制，证明了这种方案对于BEPCⅡ来说是可行的，结构和工艺设计是合理的.     

一种新型冲击磁铁的理论分析和模拟计算

在国际上已有的冲击磁铁方案不能完全满足BEPCⅡ储存环注入系统对冲击磁铁宽均匀场区、高均匀度和低束流阻抗的设计要求的情况下,提出了一种新型冲击磁铁的设计思想.理论分析和瞬态OPERA程序模拟计算的结果表明,在Δx=±20mm的范围内,中心平面上场的均匀性为±0.6%,y=5mm的平面上场的均匀性为±0.7%,y=10mm的平面上场的均匀性为±2.9%,均优于BEPCⅡ储存环注入对冲击磁铁的设计要求.MAFIA程序模拟计算的束流阻抗Z/n(eff)小于0.022Ω,小于设计要求的0.025Ω.     

激光空间相干性对照明均匀性的影响

 研究了激光相干性对照明均匀性的影响，为照明激光器的选择提供了理论参考。其中，部分相干高斯光束分解为模式间相互独立的厄米-高斯光束的迭加。采用相位屏的近似处理方法对激光通过大气湍流的传输进行计算模拟。数值模拟的结果表明：当照明光束的空间相干性降低时，其照明均匀度逐步提高。因此对于照明激光器而言，选择空间相干性较差的激光器对其照明均匀度更加有益。     

Isotopically pure uniform polymers: The final step toward true uniformity in macromolecules

Computer‐based calculations were used to simulate the mass spectra for a number of uniform macromolecules having fixed, well‐defined chain lengths. The presence of naturally occurring carbon, hydrogen, oxygen, and halogen isotopes introduced significant levels of mass heterogeneity into these systems. For a given polymer, mass variability was demonstrated to be a function of both the elemental composition and degree of polymerization of the polymer chain. In many cases, these natural variations in mass exceeded the molecular weight of one or more monomeric repeat units along the polymer backbone, effectively blurring the mass distinction between uniform polymer constructs formed from N and N+1 repeat units. The significance of isotopic diversity and its potential impact on the synthesis and physiochemical properties of highly uniform macromolecules is also discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 923–935, 2002     

光学膜层激光损伤阈值均匀性的实验研究

 镀制了多种氧化物介质薄膜。用R-on-1方法测定了膜层的激光损伤阈值。引入数据处理方法，对测试数据进行分析。结果表明，基片清洗后，若放置一段时间再镀膜，则会影响到镀膜后膜层损伤阈值的均匀性，但对损伤阈值自身大小没有影响。测试激光参数对阈值均匀性也有一定影响。     

国产家庭轿车选型优化

利用数学中的层次分析法,对人们关心的家用轿车的选购问题,进行选型优化,选择出了最优的方案,即选择出最优、最适合大家购买的车型.     

基于光克尔效应的径向光束匀滑新方案

针对惯性约束聚变装置中提高靶面辐照均匀性的要求, 提出了一种基于光克尔效应的径向光束匀滑方案, 其基本原理是利用光克尔介质和周期性高斯脉冲光束相互作用实现对激光束透射波前附加周期性的球面位相调制, 以周期性地改变激光束远场焦斑尺寸, 进而引起远场焦斑内部散斑的快速径向扫动, 从而在积分时间内抹平靶面焦斑的强度调制, 实现径向方向的光束匀滑. 通过建立基于光克尔效应的径向光束匀滑的理论模型, 分析了焦斑形态及其径向匀滑特性, 并讨论了光克尔介质的选取和径向扫动特性. 结果表明, 基于光克尔效应的径向光束匀滑方案可以有效地实现远场焦斑内部散斑的周期性径向扫动, 从而在积分时间内快速改善靶面辐照均匀性.     

Statistical properties of generalized discrepancies

When testing that a sample of points in the unit hypercube comes from a uniform distribution, the Kolmogorov-Smirnov and the Cramér-von Mises statistics are simple and well-known procedures. To encompass these measures of uniformity, Hickernell introduced the so-called generalized -discrepancies. These discrepancies can be used in numerical integration through Monte Carlo and quasi-Monte Carlo methods, design of experiments, uniformity testing and goodness-of-fit tests. The aim of this paper is to derive the statistical asymptotic properties of these statistics under Monte Carlo sampling. In particular, we show that, under the hypothesis of uniformity of the sample of points, the asymptotic distribution is a complex stochastic integral with respect to a pinned Brownian sheet. On the other hand, if the points are not uniformly distributed, then the asymptotic distribution is Gaussian.

     

Content uniformity determination of pharmaceutical tablets using five near-infrared reflectance spectrometers: a process analytical technology (PAT) approach using robust multivariate calibration transfer algorithms

Near-infrared calibration models were developed for the determination of content uniformity of pharmaceutical tablets containing 29.4% drug load for two dosage strengths (X and Y). Both dosage strengths have a circular geometry and the only difference is the size and weight. Strength X samples weigh approximately 425 mg with a diameter of 12 mm while strength Y samples, weigh approximately 1700 mg with a diameter of 20 mm. Data used in this study were acquired from five NIR instruments manufactured by two different vendors. One of these spectrometers is a dispersive-based NIR system while the other four were Fourier transform (FT) based. The transferability of the optimized partial least-squares (PLS) calibration models developed on the primary instrument (A) located in a research facility was evaluated using spectral data acquired from secondary instruments B, C, D and E. Instruments B and E were located in the same research facility as spectrometer A while instruments C and D were located in a production facility 35 miles away. The same set of tablet samples were used to acquire spectral data from all instruments. This scenario mimics the conventional pharmaceutical technology transfer from research and development to production. Direct cross-instrument prediction without standardization was performed between the primary and each secondary instrument to evaluate the robustness of the primary instrument calibration model. For the strength Y samples, this approach was successful for data acquired on instruments B, C, and D producing root mean square error of prediction (RMSEP) of 1.05, 1.05, and 1.22%, respectively. However for instrument E data, this approach was not successful producing an RMSEP value of 3.40%. A similar deterioration was observed for the strength X samples, with RMSEP values of 2.78, 5.54, 3.40, and 5.78% corresponding to spectral data acquired on instruments B, C, D, and E, respectively. To minimize the effect of instrument variability, calibration transfer techniques such as piecewise direct standardization (PDS) and wavelet hybrid direct standardization (WHDS) were used. The PDS approach, the RMSEP values for strength X samples were lowered to 1.22, 1.12, 1.19, and 1.08% for instruments B, C, D, and E, respectively. Similar improvements were obtained using the WHDS approach with RMSEP values of 1.36, 1.42, 1.36, and 0.98% corresponding to instruments B, C, D, and E, respectively.     

高均匀性的铜柱凸块电镀

随着电子产品的小型化、多功能化和高性能化的发展,促使着2D集成封装向2.5D或3D集成封装发展。铜柱凸块电镀是晶圆级三维封装的关键基础技术之一。本文研究了铜柱凸块的电镀均匀性与添加剂浓度、 镀液对流、 电流密度和电镀设备之间的影响规律。研究结果表明, 添加剂浓度、 镀液对流以及电流密度对单个铜柱凸块的平整度影响较大,而对铜柱凸块高度的均一性影响较小。相反,电镀设备对铜柱凸块的高度均一性的影响较大, 而对铜柱凸块的平整度影响较小。在三种有机添加剂中, 整平剂对铜柱凸块的平整度影响最大, 随着镀液中整平剂浓度的增加,铜柱凸块顶部形状由凸起、变为平整、 再转变为凹陷。电镀液的单向对流会导致所沉积铜柱凸块形貌发生倾斜。 高的电流密度会导致凸顶的铜柱凸块形貌。精密设计的电镀设备可以提高晶圆上电流密度分布的均匀性, 继而大幅提高电镀铜柱凸块的共面性。本文的研究结果可为铜柱凸块的电镀优化提供指导。