向量优化问题广义有效点的一个存在性定理

利用集值映射不动点定理及最优化问题与变分不等式的关系给出线性G^↑ateaux可微的锥凸映射的广义有效点的一个存在性定理。     

极限环的表达式和计算

本文提出一种解析法和数值法相结合的方法，用来计算多项式微分系统的极限环，极限环表示为x=∑k≥0(ak cos kφ bk sin kφ),y=∑k≥0(ck cos kφ dk sin kφ)，先用解析法求出小参数时极限环的初始表达式，然后用增量法和迭代法求出任意参数时极限环满足给定精度的表达式，半稳定极限环和分叉值也可以计算。     

用于全光缓存的光阈值门理论和实验研究

提出了一种基于光阈值门的全光缓存方案,采用两个非对称的SOA环形腔激光器耦合构成光阈值门,其输出光可以在两种波长上切换,可控制波长转换器实现光包路由,从而将需缓存的数据包路由到缓存端口,避免了复杂的包头处理.建立了光阈值门的理论模型,对10 Gbit/s的光阈值门的动态特性进行了数值模拟和实验研究,实验结果和理论计算结果相符合,实验也表明光阈值门两种输出状态的消光比可达30dB.     

双间隙输出腔开放腔的高频特性分析

 建立了S波段相对论速调管放大器双间隙输出腔开放腔的3维模型。采用时域有限差分法,通过监测激励电流源的响应计算了该双间隙输出腔的谐振频率、有载Q值、场分布以及特性阻抗,并分析了腔体结构尺寸对谐振频率、有载Q值和特性阻抗的影响。研究表明：腔体半径对开放腔的谐振频率影响很大,耦合孔尺寸对腔体谐振频率的影响较小;随着耦合孔张角增加,有载Q值逐渐减小;随着腔体半径增大、间隙的减小,腔体特性阻抗降低。研究结果可为S波段强流相对论速调管放大器双间隙输出腔的设计提供理论依据。     

An Experimental Study of Mg Aggregation in AA5754 Alloys by Positron Annihilation Spectroscopy

Defects in an AA5754 （Al-3.0%Mg） alloy are investigated by coincidence Doppler broadening spectroscopy and positron lifetime spectroscopy. The results indicate enhancement of positron trapping by Mg atoms in this Al-Mg alloy after quenching treatment at 623K, which may be due to the formation of vacancy-Mg complexes or the aggregation of Mg near the vacancy sites. It is speculated that the aggregation of Mg atoms in the moderate temperature range is responsible for cracking in spot welding of AA5754 alloys.     

All-Optical RZ-to-NRZ Format Conversion with a Tunable Fibre Based Delay Interferometer

All-optical format conversion from return-to-zero （RZ） to non-return-to-zero （NRZ） is demonstrated with temperaturecontrolled all-fibre delay interferometer （DI） at 20 Gb/s. The operation principle is theoretical analysed with the help of numerical simulation and spectra analysis. Theoretical analysis results are consistent well with the experimental results. The format conversion can be achieved with power penalty of 0.54 dB and with output extinction ratio 20 dB.     

Hard X-ray one dimensional nano-focusing at the SSRF using a WSi2 /Si multilayer Laue lens

The multilayer Laue lens (MLL) is a novel diffraction optics which can realize nanometer focusing of hard X-rays with high efficiency. In this paper, a 7.9 μm-thick MLL with the outmost layer thickness of 15 nm is designed based on dynamical diffraction theory. The MLL is fabricated by first depositing the depth-graded multilayer using direct current (DC) magnetron sputtering technology. Then, the multilayer sample is sliced, and both cross-sections are thinned and polished to a depth of 35-41 μm. The focusing property of the MLL is measured at the Shanghai Synchrotron Facility (SSRF). One-dimensional (1D) focusing resolutions of 205 nm and 221 nm are obtained at E=14 keV and 18 keV, respectively. It demonstrates that the fabricated MLL can focus hard X-rays into nanometer scale.     

Correction to Goldstein Equation from the Gluon Condensate Diagram

An exact Goldstein solution of the Bethe-Salpeter equation including the gluon condensate in the background field QCD is discussed.We find that the gluon condensate diagram makes quark and anti-quark more close to form a bound state.     

异核碱金属原子间的三体相互作用系数

利用碱金属原子的模型势和稳定变分法,首次计算了异核碱金属原子间的三体相互作用系数.为了说明计算结果的精度,同时计算了碱金属原子的电多级极化率.与其他作者的理论数据和有关实验数据的比较表明,本文所得到的异核碱金属原子间的三体相互作用系数是可靠的.     

比值导数法矿物组分光谱解混模型研究

矿物丰度含量的精确分析是高光谱遥感技术定量分析中的难点。将化学领域的比值导数光谱算法进行总结,将其引入遥感反射率光谱分析,提出了基于线性光谱混合模型的比值导数光谱解混模型,并利用石膏和绿帘石粉末混合物进行了模型的精度分析。实验结果表明,矿物粉末混合物在不同波段其光谱混合特性有所不同,其中部分波段有较强的线性混合特征。采用部分强线性混合波段进行光谱解混,可以取得比全波段解混算法更好的结果。比值导数法光谱解混模型简洁,可以得到高精度的矿物成分反演结果,对于固定端元组成的混合光谱定量分析有较大潜力。