具有混合导数的Sobolev类在L_q(R~d)中的平均宽度

本文研究了具有混合导数的Ｓｏｂｏｌｅｖ类ＳｒｐＷ在 Ｌｑ（Ｒｄ）中的平均σ－ Ｋ宽度（１＜ ｐ≤ｑ≤ ２）,得到了该量的弱渐近估计．     

LIFE-SPAN OF CLASSICAL SOLUTIONS TO QUASILINEAR HYPERBOLIC SYSTEMS WITH SLOWDECAY INITIAL DATA

The author considers the life-span of classical solutions to Cauchy problem for general first order quasilinear strictly hyperbolic systems in two independent variables with “slow“ decay initial data. By constructing an example, first it is illustrated that the classical solution to this kind of Cauchy problem may blow up in a finite time, even if the system is weakly linearly degenerate. Then some lower bounds of the life-span of classical solutions are given in the casethat the system is weakly linearly degenerate. These estimates imply that, when the system is weakly linearly degenerate, the classical solution exists almost globally in time. Finally, it is proved that Theorems 1.1-1.3 in [2] are still valid for this kind of initial data.     

Lp-Lq DECAY ESTIMATES FOR HYPERBOLIC EQUATIONS WITH OSCILLATIONS IN COEFFICIENTS

This work is concerned with the proof of Lp -Lq decay estimates for solutions of the Cauchy problem for utt -λ2(t)b2(t)/Δu =0. The coefficient consists of an increasing smooth function λ and an oscillating smooth and bounded function b which are uniformly separated from zero. The authors‘ main interest is devoted to the critical case where one has an interesting interplay between the growing and the oscillating part.     

具有混合导数的Sobolev类在Lq(Rd) 中的平均宽度

本文研究了具有混合导数的Sobolev类SprW在Lq()中的平均-K宽度(1<pq2),得到了该量的弱渐近估计.     

Study of K（892） mass and width splitting caused by model difference

According to the new K^＊（892）^0 and K^＊（892）^- masses reported by the BELLE experiment and the K^＊（892）^0 mass reported by the FOCUS experiment, mass splitting between neutral and charged K^＊（892） becomes very small. This is significantly different from the current world average values given by the Particle Data Group 2008. We find that there are differences between models used to fit the K^＊（892） decay invariant mass spectra in different measurements and study the model dependence in the measurement of K^＊（892） parameters. We refit the K^＊（892）^0 mass spectra of the BELLE and FOCUS experiments with the formula used by BELLE in fitting K^＊（892）^- to get new mass and width. After refitting, the K^＊（892）^0 mass of the BELLE experiment becomes 1.4 MeV/c^2 larger than the initial value and that of the FOCUS experiment is 1 MeV/c^2 smaller than the initial value. We also fit the spectra of some other experiments to extract the K^＊ （892） parameters using the BELLE K^＊ （892）^- parametrization.     

符合测量实验方法研究

讨论研究了符合测量实验的有关问题，提出实验过程中的几个方法和技巧。     

纤锌矿结构Zn1-xMgxO电子结构及吸收光谱的第一性原理研究

采用第一性原理计算方法,计算了纤锌矿结构Zn1-xMgxO(x=0,0.0625,0.125,0.25)的电子结构及吸收光谱. 计算结果表明,Mg的掺入使ZnO的电子结构发生了较大的改变,与Mg邻近的O原子得到电子的数目明显增大,进而O原子返回部分电子给邻近Zn原子. Zn-O间相互作用减弱,禁带宽度变大,这也从同一合金中Zn4s上移的程度得到证实. 其吸收光谱也随着Mg的掺入出现蓝移现象,其吸收边对应波长分别为379,366,357和333nm,与实验结果相一致.     

火焰喷雾法合成ZnO和MgxZn1－xO纳米颗粒的光学性能研究

利用火焰喷雾法成功制备了纳米级的ZnO和Mg_xZn_1-xO颗粒. 通过对样品的X射线衍射谱和场发射扫描电子显微镜照片分析，发现制备的颗粒大小较为均匀，直径在20nm左右；镁元素的掺入引起晶格常数变小. 通过透射光谱和光致发光谱的测量，发现Mg_xZn_1-xO颗粒的禁带宽度远大于ZnO颗粒的禁带宽度，同时对两组样品的紫外发光和可见发光的强度变化和发光机理进行了探讨. 关键词： 火焰喷雾 ZnO 禁带宽度 纳米颗粒     

裂变产物衰变链设计

根据核科学参考文献库,对半衰期、缓发中子发射几率等进行了更新评价,采用系统学研究和理论研究相结合的评价方法对裂变产物中不确定的基态进行了自旋指定,对部分存在问题的数据进行了必要修正;对衰变子核存在同质异能态的放射性核素,根据衰变纲图和内转换系数重新计算得到退激至子核同质异能态和基态的分支比数据。在此基础上,结合现有核结构和衰变数据库,研制了裂变产物衰变链设计专用衰变数据库,按照衰变规律,建立了裂变产物衰变路径和衰变信息的完整衰变链,本工作为裂变产物分析和裂变产额研究提供了一个便利参考。     

揭开中微子和反中微子的马约拉纳神秘面纱——无中微子双贝塔衰变低温晶体量热器实验

中微子可能的马约拉纳粒子属性超出了目前标准模型的范畴,是粒子物理与核物理研究领域最重要的科学问题之一.无中微子双贝塔衰变(0vββ)实验是能够确定中微子马约拉纳属性的唯一途径.0vββ的发现可以揭示中微子绝对质量、轻子数破缺、物质一反物质不对称等一系列自然奥秘,是当今粒子物理与核物理研究的前沿课题.在探索无中微子双贝塔...