碲基掺铒光纤放大器增益饱和特性的数值模拟

依据均匀加宽四能级结构速率方程组和光功率传输方程组,数值模拟了1520～1620nm波段范围内碲基掺铒光纤放大器(EDTFA)增益谱特性,以及EDTFA增益谱特性与输入信号光功率的关系.模拟结果显示:随着输入信号光功率的增大,EDTFA增益谱由于饱和效应而呈现平坦化特征.模拟结果与报道的实验测量结果达到了很好的一致.     

高Q Kerr介质腔中二项式光场与原子相互作用

应用全量子理论研究了在高Q Kerr介质腔中, 二能级原子与二项式光场相互作用系统中原子行为和光场的量子特性. 采用数值计算的方法, 详细讨论了光场参量和Kerr效应对原子布居反转和平均光子数的影响.研究发现当二项式光场处在中间态时, 在考虑Kerr效应的条件下,原子布居振荡加剧, 回复时间变短, 系统内平均光子数减少.     

天保宁片方剂中无机元素含量测定

本文采用原子吸收分光光度法测定了天保宁片方剂中钙、镁、铁、锰、铜、锌、镉七种无机元素的含量。结果表明 ,方剂中含有丰富的无机金属元素 ,元素含量铁 >钙 >镁 >锌 >铜 >锰 >镉 ,其中铁元素含量明显高于其他元素。它为探讨中成药方剂中无机元素含量与方剂质量控制的关系 ,为研究药物中微量元素与治疗心脑血管疾病之间的关系提供了有用的数据。     

光纤表面等离子体波传感器中膜厚与共振波长关系的实验研究

利用表面等离子体共振效应，研究了金属镀层厚度对光纤表面等离子体波传感器的影响。在其它参量一定的情况下，不同金属膜层厚度的传感器对应着不同的共振波长，根据这一特性设计了分布式光纤表达等离子体波传感器。突出优点是能进行多点测量。     

折/衍混合单透镜在目镜中的应用研究

以传统凯涅尔目镜为基础，采用ZEMAX软件，设计了衍射面位于目镜系统中不同位置时的折／衍混合目镜系统，所有系统均仅采用最普遍的K9玻璃，设计结果与传统凯涅尔目镜的光学性能进行了分析和比较。结果表明折／衍混合目镜系统在校正目镜的像差，例如像散，垂轴色差、垂轴像差，轴向像差和轴向色差等方面优于传统的凯涅尔目镜，选择合适的衍射面位置，可以同时获得符合要求的畸变，衍射面的引入，极大地减小了系统的重量和尺寸。     

Measurements of the strong coupling constant and the QCD colour factors using four-jet observables from hadronic Z decays

Data from annihilation into hadrons, taken with the ALEPH detector at the Z resonance, are analyzed. The four-jet rate is studied as a function of the resolution parameter and compared to next-to-leading order calculations combined with resummation of large logarithms. Angular correlations in four-jet events are measured and compared to next-to-leading order QCD predictions. With these observables two different measurements are performed. In a first analysis the strong coupling constant is measured from the four-jet rate yielding . In a second measurement the strong coupling constant and the QCD colour factors are determined simultaneously from a fit to the four-jet rate and the four-jet angular correlations, giving in good agreement with the expectation from QCD. Received: 14 May 2002 / Published online: 15 January 2003     

Study of the reaction pp \to pp \pi^0 within 10 MeV above the threshold

Kinematically complete measurements of the reaction were performed for beam energies in the range 292-298 MeV. We detected both protons in coincidence by using the large-acceptance COSY-TOF spectrometer and an external proton beam at COSY-JÃ&frac;lich; thus, we measured total and differential cross-sections and energy distributions. A strong enhancement was observed in the Dalitz plots due to the final-state interaction between the two outgoing protons; the data are well reproduced by Monte Carlo simulations using a standard scattering length of a₀=-7.83 fm and effective range of r₀=2.8 fm. Our measured total cross-sections are roughly larger than those of recent internal-target experiments at IUCF and CELSIUS. This discrepancy may be due to the final-state interaction pushing some events into the very small-angle region which is almost inaccessible to an internal-target experiment. In the angular distributions we found only very slight deviations from isotropy. The analysis of our momentum distributions yielded a small fraction of for Ps or Pp wave contributions.PACS:   13.75.Cs Nucleon-nucleon interactions (including antinucleons, deuterons, etc.) - 25.10.+s Nuclear reactions involving few-nucleon systems - 25.40.Ep Inelastic proton scattering - 29.20.Dh Storage rings     

Study of spin and decay-plane correlations of W bosons in the e + e$^-\rightarrow$ W + W- process at LEP

Data collected at LEP at centre-of-mass energies GeV are used to study correlations of the spin of W bosons using events. Spin correlations are favoured by data, and found to agree with the Standard Model predictions. In addition, correlations between the W-boson decay planes are studied in and events. Decay-plane correlations are measured to be consistent with the Standard Model predictions.Received: 26 October 2004, Revised: 15 January 2005, Published online: 3 March 2005     

β射线自动监测大气中PM_(10)含量的设计方案

本文论述了应用 β射线吸收定律测量大气中 PM10 含量的原理 ,分析了 G- M计数管的特性及测量数据的统计特征 ,提出了β射线法在测量大气中 PM10 含量的一种新的实现方法 .     

$\overline pp$ annihilation into four charged pions at rest and in flight

The spin-parity analysis of the data on the annihilation reaction at rest in liquid and in gaseous hydrogen at 3 bar pressure and in flight at momentum of MeV/c, collected by the Obelix spectrometer at the LEAR complex of CERN, is presented. The relative branching ratios and are obtained. It is also shown that the inclusion of the exotic meson , J^PC = 1^{- +} , mass and width , GeV/c², in its decay to , improves the fit and some implications of these results are briefly discussed. The relative S and P-wave annihilation percentages in four charged pions at two target densities are obtained.Received: 2 December 2003, Published online: 23 April 2004