INJECTIVE PRECOVERS AND MODULES OF GENERALIZED INVERSE POLYNOMIALS

Let (S,≤) be an ordered set. Recall that (S,≤) is artinian if every strictly decreasingsequence of elements of S is ?nite, and that (S,≤) is narrow if every subset of pairwiseorder-incomparable elements of S is ?nite. Let S be a commutative monoid. Unl…     

Rn上的非初等变换群及其极限集

该文对高维非初等Mò'bius变换群进行了研究,得到了一些重要性质,给出了几个关于离散准则和代数收敛性的定理.     

Photoluminescence Characterization of Silicon Nanoparticles Hybridized Europium Complex

A europium complex Eu (DBM)3 TPPO (Eu tris(benzoylmethide)-(triphenylphosphine oxide)) and silicon nanoparticles have been hybridized.The hybridization can evidently change the photoluminescence (PL) characteristics of the Eu complex in the following aspects:under an excitation of 390nm,the intensity of the PL peak at 611nm due to the ^5Du-^7F2 transition of the Eu^3 ions has been increased by 30%,and thc integrated PL intensity in the visible range has been increased by nearly 3 times;the PL excitation efficiency beyond 440nm has been improved cvidently;the peak in the PL excitation spectrum shifts from 408nm to 388nm,and the PL decay time decreases from 2.07 to 0.96μs,The experimental results indicatde that in the PL process,the photoexcited energy may transfer from the silicon nanoparticlcs to the Eu^3 ions.     

光传送网中结合传输损伤的路由和波长分配

在波长路由光网优化设计的过程中考虑了物理传输损伤造成的限制,提出了一种联合优化思路.将光信号在传输过程中的物理损伤作为问题公式的另一维约束,给出了相应的启发式算法,并按照由粗到细的机制对所提出的思路做了相应的评估,同时对负荷平衡问题作了初步的分析.数值结果表明这种算法可以获得与优化值相近的波长需求解,并且能够保证网络的传输性能,其业务分布随着备选路径的增加而趋向均衡.     

粒子鉴别中dE/dx和TOF的权重

在北京谱仪数据分析中,粒子鉴别使用了dE/dx和TOF的信息.在利用dE/dx和TOF联合鉴别粒子时,通常的做法是把两者的χ²值等权重相加(χ²方法).在不同的动量区间,dE/dx和TOF对粒子的鉴别能力不同.本文给出两者联合鉴别时不同动量区间的权重,并构造一个新的线性变量来进行粒子鉴别     

POROSITY CALCULATION OFMIXTURES OF FIBROUS PARTICLES

The initial forming of fiber blend to high green density, i.e. the packing of fibrous particles, is important to the reinforcement of composite materials. It is very useful to develop a general predictive method for the optimum selection of particle mixtures for the property control of ceramic or composite products. This paper presents such a mathematical model developed on the basis of the similarity analysis between the spherical and non-spherical particle packings and assesses its applicability to the packing of fibrous particles with discrete and/or continuous length distributions. The results indicate that the model can predict this packing system well and hence provide an effective way to solve various packing problems in the composite materials processing.     

粒子分辨CCT方法中的δ电子效应

提出了切伦科夫相关时间测量(CCT)中初始粒子在辐射体里产生的δ电子的干扰问题,以及降低干扰的方法. 通过模拟计算给出了北京τ-C工厂探测器初步设计中CCT的π/K分辨本领.     

顶夸克的发现

 今年3月2日,在美国费米国家实验室举行的报告会上,CDF和D0两个实验组分别报告了他们的实验结果,正式宣布发现顶夸克(Top Quark,也称t夸克)。     

粒子反应中初态粒子的阈能和末态粒子的最大能量问题

给出一种不依赖于具体动量图象求粒子反应中初态粒子的阈能和末态粒子最大能量的方法，并就常见的粒子反应作了讨论。     

首次测定短寿命缺中子同位素153Er和157Yb的EC/β+衰变纲图

利用¹⁶O重离子束轰击¹⁴²Nd和¹⁴⁷Sm同位素靶分别生成¹⁵³Er和¹⁵⁷Yb.借助氦喷嘴带传输系统和X-γ、γ-γ符合测量方法分离鉴别核素并测量其衰变性质.首次建立了¹⁵³Er和¹⁵⁷Yb的EC/β⁺衰变纲图.从中指认出¹⁵³Ho的一个新三(准)粒子态和两个新单粒子态,指认出¹⁵⁷Tm的一个新的同质异能态和一条新转动带.低位能级系统分析表明:在Ho和Tm这两条奇A核的同位素链中基态形状的转变区都在中子数86和88之间.