THE GENERALIZED RIEMANN PROBLEM FOR A SCALAR COMBUSTION MODEL --THE PERTURBATION ON INITIAL BINDING ENERGY

In this paper, we study the generalized Riemann problem for a scalar Chapman-Jouguet combustion model in a neighborhood of the origin on upper half of the （x, t）plane. We focus our attention on the perturbation on initial binding energy. Under the entropy conditions, the solutions are obtained constructively. It shows that the perturbed Riemann solutions possess the structural stability except the case that the corresponding Riemann solutions contain CJDT, for which CJDT may transform into SDT after perturbation on initial binding energy in the neighborhood of the origin.     

一类带有Holling Ⅱ类功能性反应和相互干扰及脉冲效应的捕食系统

A kind of predator-prey system of Holling typeⅡand interaction perturbation with impulsive effect is presented.By using Floquet theory and small amplitude perturbations skills,the locally asymptotical stability of prey-eradication periodic solution and the permanence of the system are discussed and the corresponding threshold conditions are given respectively.Finally,the existence of positive periodic solution is investigated by the bifurcation theory.     

ф900带软硬环的土平面波加载器研制

介绍了用于抗爆试验研究的900带软硬环的土平面波加载器的研制过程、静力与动力验证试验。由于采用了软硬环试验箱体以保证箱体的轴向柔性及径向刚性技术，验证性试验比较好地模拟了介质的一维平面应变运动。验证性试验结果表明该试验装置得到了预期的设计要求。     

First-Principles Calculations of Elastic Constants of Superconducting MgB2

The five independent elastic constants of superconducting MgB2 are obtained using the first-principles plane wave method with the new relativistic analytic pseudopotential of the Hartwigsen-Goedecker-Hutter (HGH) scheme in the frame of local density approximation. The dependences of bulk modulus on temperature and pressure are also obtained. It is suggested that the HGH-type pseudopotentials are successful in investigating the ground-state mechanical properties of any solids.     

大带隙二维三角格子光子晶体结构参数的优化设计

光子晶体结构设计优化是理论研究的一个重要内容.运用平面波展开法对圆柱、方柱及正六边柱构造的二维三角格子光子晶体的禁带进行仿真计算,讨论了介质材料分别为GaAs、Si和Ge情况下,柱子形状、旋转角度、填充比的变化对完全光子禁带的影响.发现:对于二维三角格子光子晶体,相对于介质柱,空气柱更易获得完全光子禁带;而相对于圆柱及...     

Theoretical study on the Rocksalt structured positron annihilation in magnesium oxide

Based on the atomic superposition approximation （ATSUP） and first-principles pseudopotential plane-wave methods, the bulk and Mg mono-vacancy positron lifetime of magnesium oxide were calculated using Arponen-Pajamme and Borofiski-Nieminen positron-annihilation-rate interpolation formula respectively. The calculated values are in good agreement with experimental values and the first-principles method gives more convincing results. The positron annihilation density spectra analysis reveals that positrons mainly annihilate with valence electrons of oxygen atoms when the magnesium-vacancy appears within magnesium oxide.     

Method of sensitivity improving in the non-dispersive infrared gas analysis system

A method of interference correction for improving the sensitivity of non-dispersive infrared (NDIR) gas analysis system is demonstrated. Based on the proposed method, the interference due to water vapor and carbon dioxide in the NDIR NO analyzer is corrected. After interference correction, the absorbance signal at the NO filter channel is only controlled by the absorption of NO, and the sensitivity of the analyzer is improved greatly. In the field experiment for pollution source emission monitoring, the concentration trend of NO monitored by NDIR analyzer is in good agreement with the differential optical absorption spectroscopy NO analyzer. Small variations of NO concentration can also be resolved, and the measuring correlation coefficient of the two analyzers is 94.28%.     

HARMONIC OSCILLATORS AT RESONANCE,PERTURBED BY A NON-LINEAR FRICTION FORCE

This note is an addendum to the results of Lazer and Frederickson [1], and Lazer [4] on periodic oscillations, with linear part at resonance. We show that a small modification of the argument in [4] provides a more general result. It turns out that things are different for the correspouding Dirichlet boundary value problem.     

Singular value decomposition with normalized period for magnetocaridiography signal processing

In this paper, we have developed an algorithm based on singular value decomposition (SVD) for matrix. And the novel SVD algorithm with normalized period of cardiac cycles is presented. The results from real magnetocardiography (MCG) data processing show that the new algorithm is better than the standard one not only in suppressing noises, but also in providing high-fidelity MCG signals.     

火焰原子吸收法测定硅酸盐中铁钙镁

研究火焰原子吸收法测定硅基体中铁、钙、镁时，硅对待测元素吸收信号的干扰及表面活性剂对硅干扰的抑制作用。以十六烷基吡啶盐（ＣＰＣ）作干扰抑制剂，ＦＡＡＳ法测定硅酸盐中铁、钙、镁等元素，灵敏、简便、无干扰。合成样品中铁、钙、镁的回收率分别为９９．８％、１０１．３％和９８．３％。