康普顿背散射技术对贮存环电子束诊断及其应用 II贮存环电子束的极化度测量

简单介绍以激光 电子康普顿背散射原理为基础建立的康普顿背散射极化仪,采用它能实时、非破坏性地监测电子束的极化.该项工作可作为上海激光电子γ源(SLEGS)低能γ束应用研究的内容之一.     

类铍离子内壳激发态1s2p3 3P0、3D0及2s2p3 3D0 的俄歇宽度和俄歇分支率

采用鞍点变分方法和鞍点复数转动方法并考虑相对论修正和质量极化效应,计算了类铍离子内壳激发态1s2p3 3P0、3D0和内壳双激发态2s2p3 3D0的俄歇宽度、俄歇分支率和俄歇电子能量.同时还对1s22p2 3Pe态到1s2p3 3P0、3D0态(Z=4~10)的振子强度和辐射跃迁率进行了计算,计算结果与其他理论结果以及实验数据符合得很好.     

Development of the Technique for Fabricating Submicron Moire Gratings on Metal Materials Using Focused Ion Beam Milling

A focused gallium ion （Ga＋） beam is used to fabricate micro/submicron spacing gratings on the surface of porous NiTi shape memory alloy （SMA ）. The crossing type of gratings with double-frequency （25001/mm and 50001/mm） using the focused ion beam （FIB） milling are successfully produced in a combination mode or superposition mode. Based on the double-frequency gratings, high-quality scanning electron microscopy （SEM） Moird patterns are obtained to study the micro-scale deformation of porous NiTi SMA. The grating fabrication technique is discussed in detail. The experimental results verify the feasibility of fabricating high frequency grating on metal surface using FIB milling.     

Audio watermarking based on psychoacoustic model and critical band wavelet transform

Watermark embedding algorithm based on critical band wavelet transform of digital audio signal is proposed in this paper. The masking threshold for each audio signal segment was calculated on the basic of psychoacoustic model. According to the similarity between critical band of human auditory system and critical band wavelet transform, a watermark was embedded into the low-band and mid-band coefficients of digital wavelet. The embedding strength was adaptively controlled by the masking threshold. The experiment results show that the embedded watermark signal is inaudible, and the watermarked audio signal has good robustness against many attacks such as compression, noise, re-sampling, low-pass filtering.     

顶色辅助的人工色模型下顶夸克极化效应的研究

在顶色辅助的人工色(TC2)理论下, 在强子对撞机上研究了顶夸克-反顶夸克对的产生过程中顶夸克的极化效应, 在计算过程中, 运用了MRS set A'部分子分布函数和螺旋度投影算符的方法. 研究结果表明: 在Tevatron上顶夸克的极化效应太小不可探测; 参数选取得当, 该效应在LHC上可以探测到, 其值可达16%. 因此, 顶夸克的极化效应提供了一种切实可行的检验顶色辅助的人工色模型的方法.     

基于分位数回归的大学生成绩变化实证分析

在介绍分位数回归方法的基础上,讨论了分位数回归模型在研究影响大学生成绩变化因素方面的应用,与最小二乘回归模型对比,分位数回归能有效地描述数据尾端的分布情况.     

大孔吸附树脂分离提取羟丙腈的研究

本文考察了三种大孔吸附树脂对羟丙腈（HPN）的吸附能力，其中NKA－Ⅱ效果较好，表态吸附容量的82.5mg/mL，甲醇是较适宜的洗脱剂。并用动态实验研究了HPN浓度、流速、盐浓度对NKA－Ⅱ树脂吸附能力的影响，将NKA－Ⅱ树脂直接用于丙烯腈水合反应液中羟丙腈的分离提取，回收率高于90％。     

静动干涉流动的分离涡模拟研究

本文基于一种并行高精度的静动交接面处理方法,采用了SA模型及基于SA的分离涡模拟DES方法,进行了某压气机静动干涉流动的计算.研究表明对本文算例,在微小分离处,如20%到80%叶高处,DES与SA计算出的流动损失相差很小;而在大分离处,如叶根叶顶处,DES结果与SA差别较大,并且DES可更好地描述涡结构.在叶顶处,DES计算出比SA更强的泄漏流动,导致更大的损失.在叶根处,DES计算出了明显的静叶动态尾迹涡脱落现象,这一现象导致了与SA不一样的损失机理,即脱落涡与动叶头部相撞而产生时序效应,从而使计算损失较小.同时,本文研究结果与之前对孤立静叶的研究是相互验证的.     

Synthesis and Properties of D-Thymidylyl (3'→5')L-Thymidine (D/L-TpT)

Inrecentyearsmuchefforthasbeenspenttodevelopoligonucleotideanalogsashighlyselectivepharmaceuticalagentstoblockexpressionofdisease-associatedproteins'-'.andtheseefT'ortshaveresultedilltheapprovaloffomiversensodium(vitravene',"),thefirstantisensedrug,byFDAinAugust1998fortreatmentofAIDSpatientswithcytomegalovirus(CMV)-inducedretinitis6.However,thegreatpotentialofantisenseoligonucleotidesasantiviralandanticanceragentsiscompromisedbytheirnucleasesusceptibilityandlowcellmembranepermeability.L-D…