探索物质的极限——CERN超相对论性核碰撞

20世纪70年代,人们发现了强相互作用的基本理论——量子色动力学（QCD）。     

Charge fluctuations in Au+Au collisions at RHIC energy

A hadron and string cascade model, JPCIAE, together with the corresponding Monte Carlo event generator, has been employed in this paper to investigate further the charge fluctuations in Au+Au collisions at Snn = 130 GeV. The default JPCIAE calculations are in good agreement with PHENIX and STAR data. We found that the thermal predictions for the π gas, the resonance π gas and quark matter deviate, respectively, from the corresponding dynamical simulations from the JPCIAE model. The discrepancies were also found between the π charge fluctuations and the charge fluctuations of all species of hadrons. However the charge fluctuations for "π from ρ and ω decay" and for all the hadrons from resonance decay are close to each other, indicating the correlation between positively and negatively charged hadrons is not sensitive to the species of hadrons. This work shows further that it is questionable to use the charge fluctuations as a signature of QGP.     

粲夸克辐射的死区效应

基于轻夸克辐射能量谱, 考虑夸克质量对部分子辐射能量损失的影响, 利用死区因子把轻部分子辐射能量损失谱推广到重部分子辐射能量损失的情形. 研究结果表明, 利用与夸克质量相关的死区因子推广轻夸克辐射能量损失谱得到的重夸克辐射能量损失谱, 与直接利用微扰QCD计算所得到的Djordjevic-Gyulassy(D-G)谱的结果一致, 且极大简化了重夸克辐射能量损失的计算.     

ALICE新内寻迹系统——硅像素探测器

大型重离子对撞机实验（ALICE）是大型强子对撞机（LHC）上唯一致力于研究极端相对论下的原子核碰撞的实验。其目标是研究强相互作用物质在实验室达到的极高能量密度下的物理特性。在极高能量密度下,能够产生一种新的物质形态——夸克-胶子等离子体。宇宙被认为在大爆炸后的最初几百万分之一秒就处于夸克-胶子等离子体状态。     

1.82-μm distributed feedback lasers with InGaAs/InGaAsP multiple-quantum wells for a H2 O sensing system

High-strained InGaAs/InGaAsP multiple quantum wells （MQWs） distributed feedback （DFB） lasers, fabricated using metal organic chemical vapor deposition, are presented at 1.82 μm with a high side-mode-suppression ratio of 49.53 dB. The current- and temperature-tuning rates of the DFB mode wavelength are 0.01 nm/mA and 0.13 nm/℃, respectively. A characteristic temperature of 51 K is also confirmed. The DFB laser demonstrates good performance and can be applied to H₂ O concentration sensing.     

土壤中六种新烟碱类农药残留的分离及光谱研究

建立了一种可同时检测土壤中吡虫啉、啶虫脒、噻虫嗪、噻虫啉、噻虫胺、烯啶虫胺六种新烟碱类农药残留的方法,该方法操作简单、成本低廉且重现性好,符合环境研究过程中实验量大、样品量多的特点。土壤样品经乙腈：二氯甲烷(2∶1 φ)提取后,进一步用分散液液微萃取处理。分析方法采用Alltima TM C18 色谱柱(4.6 mm×250 mm,5 μm)分离,PDA检测器检测,外标法定量。六种农药在0.5～200 μg·L-1浓度范围内线性关系良好,相关系数为0.998 2～0.999 9,检测限为0.000 5～0.003 μg·mL-1 (S/N=3)。以五种土壤为代表,在0.05,0.1,1.0 mg·kg-1 三个添加水平的平均加标回收率为55.3%～95.6%,相对标准偏差为1.4～7.0%。同时应用紫外分光光度法对净化效果进行考察,证明本实验所建立的方法具有明显的净化作用,因此满足土壤中六种新烟碱类农药残留检测的要求。     

基于判别矢量子空间的雷达目标距离剖面像识别

提出了一种基于判别矢量子空间的雷达目标距离剖面像识别方法。判别矢量子空间一方面在分析意义上是较优的,同时该子空间的维数不受目标类别数限制,从而能够提取更有效的目标分类特征,改善目标正确识别率。仿真实验结果表明：该方法识别率高于特征图像方法和正则子空间法。     

Oscillations of moments in high-energy nucleus-nucleus collisions

The definitions of density function and moment of multiplicity distribution are introduced, and the method of moment analysis in e⁺e^- and proton-proton (pp) interactions is extended into nucleus-nucleus (AA) interactions. We analyze the data for relativistic nucleus-nucleus collisions and calculate the values of H_q for charged particle multiplicity distributions, by which we study systematically the dependences of H_qon incident energy, mass of colliding system, pseudorapidity interval, centrality and truncation of multiplicity. We compare the oscillation structures induced by e⁺ e^-, pp and AA interactions, and the comparison and analysis are carried out between experimental data and QCD prediction. The latest results are given in this paper.     

网络规划中LAC区的合理划分

LAC区用于标识不同的位置区,LAC区的划分合理与否,直接关系到网络的质量,本文简要分析了影响LAC划分的不同因素,并以西安移动业务区为例,得出简要结论。