捕食系统的研究

研究了具有稀疏效应和投放的周期系统是持久的且有唯一严格正的全局渐近稳定的周期解。     

SUSY QCD Residual Effects in pp→bbh Process

If all the supersymmetry particles (sparticles) except a light Higgs boson are too heavy to be directly produced at the Large Hadron Collider (LHC), a possible way to reveal evidence for supersymmetry is through their virtual effects in other processes. We examine such supersymmetric QCD effects in bottom pair production associated with a light Higgs boson at the LHC. We find that if the relevant sparticles (gluinos and squarks) are too heavy to be directly produced well above the TeV scale, they can still have sizable virtual effects in this process. For large tanβ, such residual effects can alter the production rate by over 40 percent,which should be observable in future measurements of this process at the LHC.     

两性聚丙烯酰胺乳液选矿剂的合成及絮凝作用

两性聚丙烯酰胺乳液选矿剂的合成及絮凝作用;两性聚丙烯酰胺;乳液选矿剂;铝土矿赤泥;絮凝机理     

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以某跨声速轴流压气机单转子为研究对象,应用数值模拟技术,采用全通道 计算方案,利用Jameson有限体积中心差分格式并结合Spalart-Allmaras 湍流模型获得进口畸变条件下该轴流压气机转子性能和内部流动细节,详细分析了进气周向 总压畸变对压气机转子内流场流动结构的影响. 并将计算结果与实验结果进行了比较, 结果表明,数值模拟的结果与实验结果符合较好,计算方案切实可行.     

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针对汽车冲撞行人抛出速度问题,利用人体直杆模型,运用有关力学原 理,得出汽车与行人第一次冲撞后人体的转动角速度和平动速度,进而讨论了不同冲撞车速 下人体倒向发动机罩的可能运动状态,结果比较符合实际情况.这对交通事故鉴定工作具有应 用价值.     

The Role of Potential Structure in Excitation Functions of Synthesizing Superheavy Nuclei

The excitation functions of two very similar reaction channels, 58Fe＋ 208pb→ 265Hs ＋ 1n and 58Fe＋ 209Bi → 266Mt ＋1n are studied in the framework of the dinuclear system conception. The fusion probabilities are found to be strongly subject to the structure of the driving potential. Usually the fusion probability is hindered by a barrier from the injection channel towards the compound nuclear configuration. The barrier towards the mass symmetrical direction, however, also plays an important role for the fusion probability, because the barrier hinders the quasi-fission, and therefore helps fusion.     

Magnetotransport in a dual waveguide coupled by a finite barrier： Energy filter and directional coupler

We propose in this paper that a dual waveguide coupled by a finite barrier be able to serve as an energy filter under a perpendicular magnetic field. In the waveguide direction, the conductance exhibits a periodic square-wave pattern in which the miniband is controlled by the magnetic and potential modulation. The electrons with energies in the miniband can completely transfer along one waveguide while the other electrons undergo filtration. Compared with the coupled waveguide without magnetic modulation, the structure under magnetic field is found to be a good directional coupler. By adjusting the potential barrier and magnetic field, the electrons input from one port of waveguide can transfer to any other ports.     

Cosmic Ray Flux Variation due to Solar Flares during January 16—20, 2005 with YBJ-ARGO Experiment

The YBJ-ARGO experiment is located in Tibet at 4300m a.s.l.. The data of this experiment under scalar mode can be used to study the solar modulation of cosmic ray flux at E>10GeV. The data during January 15—17, 2005 are analyzed, and a cosmic ray flux Forbush decrease after several X class solar flares has been observed. All detailed structures of the flux curves are similar to the results from neutron monitors. The maximum amplitudes of FD are about －6%, －6%, －4% and －3% with multiplicity greater than 1, 2, 3 and 4, respectively, i.e. the maximum amplitude of FD decreases as the energy of cosmic ray increases. These are the results about a FD measured at the same site (Yangbajing) with different cosmic ray energies for the first time.     

光谱学方法研究介质阻挡沿面放电辉光模式的电场分布

利用介质阻挡沿面放电装置,在低气压空气中实现了辉光放电模式。利用光电倍增管对放电发光信号进行检测,发现外加电压每半周期出现一个发光脉冲,并且正负半周期的光脉冲是不对称的。利用Photoshop软件处理放电的照片,研究发现平行于高压电极不同位置的发光强度基本相同,然而距离高压电极越远,发光强度减小。放电中总电场由外加电场和电介质积累的壁电荷电场共同决定,确定该电场具有重要意义。通过分析放电的发射光谱中N+₂(B 2Σ+_u→X 2Σ+_g)谱线391.4 nm和N₂的第二正带系(C 3Π_u→B 3Π_g)谱线337.1 nm的比值,可以定性地说明电场的分布。研究发现电场在高压电极附近较大而远离高压电极处较小。这些研究结果对沿面放电的数值模拟和工业应用具有重要的价值。     

在NiMnCo-Cu-C体系中生长宝石级金刚石单晶

利用温度梯度法在NiMnCo-Cu-C体系、于5.5 GPa、1250℃条件下进行了宝石级金刚石单晶的生长研究,结果发现,Cu片在触媒中的放置位置和其在金属触媒中所占体积分数对宝石级金刚石单晶的生长具有明显影响.当Cu片放置在碳源和触媒之间时,将不会有充足的碳源扩散到籽晶上,晶体无法生长;但放在触媒中其他位置,体积分数适当时,不会对晶体生长有明显影响.随着Cu体积分数增加,优质晶体生长将变得困难,当体积分数在20;时,晶体有生长,但晶体内部跟表面明显存在由于包裹体存在造成的生长坑洞;当体积分数在40;左右时,晶体将不再生长.不过当Cu在触媒中的体积分数适当时,会降低碳源在触媒中的输运,从而对抑制自发核生长起到一定的作用.