包围多个奇点的极限环的个数

本文对Lienard系统包围多个奇点的极限环的唯一性和唯二性给出若干充分条件．     

用YAG激光制备类金刚石薄膜及其光学折射率研究

用高功率的Ｎｄ＾３＋：ＹＡＧ脉冲激光轰击真空室内的石墨靶，形成激光等离子体雾状物质，在硅衬底上沉积形成类金刚石薄膜，用椭圆偏振光谱法测量不同衬底温度下制备的系列样品的厚度和折射率，发现随着衬底温度的升高，薄膜的厚度减小而的折射率增大，这种可以控制折射率米化的薄膜，可能为光学增透增反膜的制备提供一种新方法。     

五磷酸镧钕激光晶体发光的温度效应

研究了低温下Nd0.9 La0.1 P5O14晶体中,Nd3+离子在0.9,1.05,以及1.35μm附近发光光谱的精细结构及相应的跃迁过程,并与Nd:YAG晶体中Nd3+离子发光光谱及相应的跃迁作了比较。在77K-500K的温度变化范围内,研究了Nd3+在两种晶体中最强的发光线的温度依赖关系,发现相反的变化规律,指出这是与两种晶体的结构及跃迁过程有关。     

Lienard系统的同宿轨族与闭轨族

本文讨论Ｌｉｅｎａｒｄ系统解的一些定性性质，得到了存在同宿轨族、闭轨族、双曲扇形和椭圆扇形、正负半轨有界及其与等倾线相交的充要条件或充分条件．     

CFD simulation of gas–solid flow with a cluster structure-dependent drag coefficient model in circulating fluidized beds

To model the effect of clusters on hydrodynamics of gas and particles phases in risers, the interfacial drag coefficient is taken into account in computational fluid dynamic simulations by means of a two-fluid model. The momentum and energy balances that characterize the clusters in the dense phase and dispersed particles in the dilute phase are described by the multi-scale resolution approach. The model of cluster structure-dependent (CSD) drag coefficient is proposed on the basis of the minimization of energy dissipation by heterogeneous drag (MEDHD) in the full range of Reynolds number. The model of CSD drag coefficient is then incorporated into the two-fluid model to simulate flow behavior of gas and particles in a riser. The distributions of volume fraction and velocity of particles are predicted. Simulated results are in agreement with experimental data published in the literature.     

Double-image encryption based on iterative gyrator transform

A novel double-image encryption algorithm is proposed, which can simultaneously encrypt two images into a single one as the amplitude of gyrator transform with two different groups of angles. The two original images can be retrieved independently by gyrator transforms with two different groups of angles, one common phase mask, and two different private phase masks. The proposed approach can enlarge the key space, achieve faster convergence in iterative process, and avoid cross-talk between two images in reconstruction. Numerical simulations are presented to verify its validity and efficiency.     

Ionic self-assembled organic nanobelts from the hexagonal phase complexes and their cyclodextrin inclusions

The supramolecular ionic self-assembly (ISA) strategy has been used to construct the long-range ordered hierarchical aggregates from the complexes of 1-adamantanamine hydrochloride (AdCl) and sodium bis(2-ethyl-1-hexyl)sulfosuccinate (AOT). The formed AOT-Ad complexes have been proved to possess a composition of equal molar ratio and a hexagonal columnar structure with Ad blocks as the core and AOT outside. More interestingly, the length, width, and thickness of the aggregates are on the order of milli-, micro-, and nanometer, respectively, and can thus be taken as one type of organic nanobelt. Such nanobelts are plastic and stable to resist breakage even bent to a circle, which makes them useful in the fields of novel nanomaterial fabrication. In addition, the ISA process of this aggregate can be tuned by including Ad blocks in beta-cyclodextrins to form a supramolecular complex, which is comparatively stable in the water and expected to self-assemble into some other ordered structures.     

Electrochemical strategy for ultrasensitive detection of microRNA based on MNAzyme-mediated rolling circle amplification on a gold electrode

Microchimica Acta - The authors describe an electrochemical strategy for ultrasensitive and specific detection of microRNA (miRNA). It is based on both multicomponent nucleic acid enzyme (MNAzyme)...     

Lyotropic liquid crystalline phases in a ternary system of 1-hexadecyl-3-methylimidazolium chloride/1-decanol/water

Lyotropic liquid crystals formed in a ternary system of 1-hexadecyl-3-methylimidazolium chloride ([C16mim]Cl), 1-decanol, and water at 25 degrees C are reported. The hexagonal and lamellar phases were characterized by small angle X-ray scattering and polarizing optical microscopy. In the phase diagram, the system shows two isotropic liquid phases, a hexagonal phase connected to the [C16mim]Cl-water axis, and a lamellar phase in the center. The formation of liquid crystalline phases is believed to arise from a hydrogen-bonded network comprised of an imidazolium ring, anion, 1-decanol, and water. In the liquid crystal, the intercalation of 1-decanol between neighboring [C16mim]Cl molecules favors the appearance of lamellar phases. The phase behavior of the present system is discussed in comparison with a similar ternary system of cetyltrimethylammonium bromide (CTAB).