小企业大未来

经历全球金融危机的洗礼之后,整个亚洲的中小企业正处于迅速恢复之中。这体现了中小企业的非凡弹性和适应性。对于比以往任何时候都更加依赖这些充满活力的企业,来实现繁荣发展的亚洲国家来说,这也是振奋人心的好消息。     

Triatomic wake effect and the determination of the molecular structure of HD2+ from the Coulomb explosion

A new theoretical model of the triatomic molecular wake effect is proposed and applied to molecular ions D+ 3 and HD+ 2 while passing through a solid.The wake effects resulting from the reactions of the two similar ions with thin carbon foil are also investigated by using the Coulomb explosion technique.The experimental results are in good agreement with theoretical estimates and the molecular structure of HD+ 2 is determined by using the model.     

LPCVD Si基转换生长3C-SiC薄膜的光学性质初探

本文采用LPCVD技术在高温条件下, 利用甲烷和氢气混合气体作为碳源, 在n-Si(111)衬底上制备3C-SiC薄膜。通过XRD、XPS、SEM、FT-IR和PL研究发现: 温度对3C-SiC薄膜的形貌和晶体质量有较大的影响, 并且生长温度对3C-SiC薄膜的780 cm-1左右的FT-IR反射峰强度影响非常大; 在室温测试条件下, 3C-SiC薄膜有较强的蓝光波段的荧光峰。     

一类新的混沌神经放电的动力学特征的实验和数学模型研究

神经元电活动理论模型Hindmarsh-Rose(HR)模型提示有位于周期1和周期2放电模式之间的一类特殊的混沌放电,但长期以来对其没有获得足够认识.依据回归映射的确定性结构和非线性预报的短期可预报性,确认了在大鼠的实验性神经起步点的实验中发现的位于周期1和周期2放电模式之间的非周期放电是混沌放电模式,还将该混沌放电模式区分为3个不同表观样式.其中1个表观形式与HR模型的仿真结果相类似,验证了HR模型的理论预期;其余2个样式与仿真结果并不相似.进一步揭示了3个表观样式的动力学特征以及相互之间的区别与联系,并与位于周期2和周期3节律之间、周期3和周期4节律之间的混沌比较了异同,也区别了从周期1到混沌再到周期2放电模式的节律转迁历程与其他的从周期1到周期2节律的分岔过程的不同.研究结果确认了该类特殊混沌节律和相应分岔过程的新特征,丰富了混沌放电节律和节律分岔序列的种类.还对仿真该混沌的多样性和非光滑特性,以及揭示该类混沌的产生途径等进行了讨论. 关键词： 混沌 神经放电模式 分岔 节律     

可移动半无限垂直圆柱体温度交变振荡时对MHD自由对流的影响

不可压缩粘性流体,流过可移动、温度交变振荡的半无限垂直圆柱体时,对MHD自由对流影响的数值解进行了研究.应用Crank-Nicolson型的隐式有限差分方法,求解无量纲、不稳定、非线性、耦合的偏微分控制方程.在不同参数下研究速度、温度和浓度分布的变化,还分析了局部及平均的表面摩擦力、Nusselt数和Sherwood数,并以图形形式给出.所得结果与其他文献的结果比较,有着很好的一致性.     

智能手机在生化传感分析中的应用进展

该文主要综述了基于智能手机生化检测的光学和电化学检测技术,及其在生化传感分析中强大的通信手段。重点介绍了智能手机集成的生化传感器技术的性能、优点,及其在生化检测中的应用,讨论了目前智能手机在生化传感分析方面存在的局限性和面临的挑战,并展望了未来的发展方向和潜在的机遇。     

一个特征值问题的迹公式

本文利用逼近理论的方法,分别提出了一个特征值问题在周期条件下以及在无穷衰减条件下的迹公式。     

左连续环中若干链条件的等价性

(1)设R是左连续环,则R是左Artin环当且仅当R满足左限制有限条件当且仅当R关于本质左理想满足极小条件当且仅当R关于本质左理想满足极大条件.同时给出一个左自内射环是QF环的充要条件;(2)证明了左Z₁-环上的有限生成模都有Artin-Rees性质.     

Direct Observation of High-Temperature Superconductivity in One-Unit-Cell FeSe Films

We prepared one-unit-ceil （1-UC） thick FeSe films on insulating SrTiOa substrates with non-superconducting FeTe protection layers by molecular beam epitaxy for ex situ studies. By direct transport and magnetic measurements, we provide definitive evidence for high temperature superconductivity in the 1-UC FeSe films with an onset Tc above 40 K and an extremely large critical current density fie Jc-1.7× 106 A/cm2 at 2K, which are much higher than Tc-8K and Jc-104 A/cm^2 for bulk FeSe, respectively. Our work may pave the way to enhancing and tailoring superconductivity by interface engineering.     

Electronic and magnetic properties of BiFeO_3 with intrinsic defects:First-principles prediction

The electronic structure, magnetism, and dielectric functions of BiFeO3 with intrinsic vacancies, including Bi-, Fe-, and O-vacancies （denoted as VFe, VBi, and Vo, respectively） are investigated using the first-principles density functional theory plus U calculations. It is revealed that the structural distortions associated with those vacancies impose significant influences on the total density of state and magnetic behaviors. The existence of VBi favors the excitation of the O2p state into the band gap at 0.4 eV, while the O2p and Fe3d orbitals are co-excited into the band gap around 0.45 eV in VFe- Consequently, a giant net magnetic moment of 1.96 P-B is generated in VFe, and a relatively small moment of 0.13 P-B is induced in VBi, whereas Vo seems magnetically inactive. The giant magnetic moment generated in VFe originates from the suppression of the spatially modulated antiferromagnetic spin structure. Furthermore, VFe and VBi have strong influences on dielectric function, and induce some strong peaks to occur in the lower energy level. In contrast, VO has a small effect.