A high sensitivity optical gyroscope based on slow light in coupled-resonator-induced transparency

We designed ring-in-ring planar resonator which is coupled with a straight waveguide to yield coupled-resonator-induced transparency (CRIT). The model shows an obvious effect which has a direct analogy with the phenomenon of the electromagnetically induced transparency in quantum systems. Based on this structure, a high sensitive optical gyroscope for measuring absolute rotation is proposed and analyzed. Its sensitivity scales directly with the group index whose can be reached to ¹⁰²-¹⁰⁴ orders of magnitude by using proper parameters.     

Nitrogen-doped multiwalled carbon nanotubes and their electrocatalysis towards oxidation of NO

Nitrogen-doped multiwalled carbon nanotubes (N-MWCNTs) were synthesized by thermal decomposition of pyridine and iron phthalocyanine over an iron catalyst in an atmosphere of ammonia. The N-MWCNTs thus obtained were analyzed by X-ray photoelectron spectroscopy. They were found to contain three types of nitrogen (N) atoms, namely pyridine-like, graphite-like, and molecular N. The effect of the pyridine-like N and the graphite-like N was investigated. The pyridine-like N is absorbing nitric oxide (NO) more easily than the graphite-like N. The N-MWCNTs with higher N content (especially the pyridine-like N) have higher catalytic activity (in terms of electrooxidation of NO) than those containing less N. The N-MWCNTs with high levels of pyridine N were incorporated into an electrode which suitable for sensing NO and for removal of NO due to its excellent electrocatalytic activity.     

Delay limit of slow light in an optical fiber

We show that coherent population oscillations effect produces a very narrow spectral hole in the absorption spectrum. The large dispersion of the refractive index associated with this hole permits us to achieve a group velocity as low as 1496.25 m/s at room temperature in an erbium-doped fiber. When the input intensity is equal to the saturation intensity, the dispersion is optimal. The optimal dispersion corresponds to the maximum fractional delay. Therefore, the input intensity can be used as a control parameter to increase the fractional delay. Our theoretical results based on population oscillation agree very well with the experimental data. In addition, we confirm that the spectral hole experiences power broadening for optical fibers of different lengths.     

一类具有逐段常变量微分方程的渐近概周期解

利用差分方程的渐近概周期序列解，讨论了一类具有逐段常变量微分方程的渐近概周期解的存在性．     

Dispersion coefficients for Li+–H and Li+–He systems with coulomb and screened coulomb potentials

Exploiting powerful computational aspects and highly correlated exponential wave functions for two‐electron atoms, we have investigated the effects of screened Coulomb interaction on the hexadecapole polarizability of Li⁺(1¹S), and the dispersion coefficients C₆, C₈, C₁₀, and C₁₂ for interaction of Li⁺ with H and He atoms in their ground states. The dispersion coefficients and hexadecapole polarizability for different screening parameters ranging from 0 to 1.0 a are reported. In the unscreened case, the hexadecapole polarizability of Li⁺, and the dispersion C₁₂ coefficients for Li⁺–H and Li⁺–He system are reported for the first time in the literature. The C₆, C₈, and C₁₀ coefficients for the unscreened cases are comparable with the reported results. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Theoretical study and rate constants calculation for the reactions X + CF3CH2OCF3 (X = F,Cl, Br)

The multiple‐channel reactions X + CF₃CH₂OCF₃ (X = F, Cl, Br) are theoretically investigated. The minimum energy paths (MEP) are calculated at the MP2/6‐31+G(d,p) level, and energetic information is further refined by the MC‐QCISD (single‐point) method. The rate constants for major reaction channels are calculated by canonical variational transition state theory (CVT) with small‐curvature tunneling (SCT) correction over the temperature range 200–2000 K. The theoretical three‐parameter expressions for the three channels k_1a(T) = 1.24 × 10^?15T^1.24exp(?304.81/T), k_2a(T) = 7.27 × 10^?15T^0.37exp(?630.69/T), and k_3a(T) = 2.84 × 10^?19T^2.51 exp(?2725.17/T) cm³ molecule^?1 s^?1 are given. Our calculations indicate that hydrogen abstraction channel is only feasible channel due to the smaller barrier height among five channels considered. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2012     

A Fungus Capable of Degrading Microcystin-LR in the Algal Culture of <Emphasis Type="Italic">Microcystis aeruginosa</Emphasis> PCC7806

Microcystins (MCs) are a family of natural toxins produced by cyanobacteria (blue-green algae). Microbial degradation is considered an efficient method for eliminating cyanobacteria and MCs in environmental conditions. This study examines the ability of Trichaptum abietinum 1302BG, a white rot fungus, to degrade microcystin-LR in the harmful algal culture of Microcystis aeruginosa PCC7806. Results showed that microcystin-LR could not be detected by high-performance liquid chromatography after 12 h in algal culture incubated with the fungus. There were also high activities of catalase and peroxidase in algal culture incubated with the fungus. However, similar to the control, they decreased to normal levels after 72 h. Meanwhile, the micronucleus test in the toxicity studies revealed that the degraded algal culture had low toxicity.     

纳米材料在重金属离子分离富集中的应用

综述了纳米材料(包括氧化物、表面修饰氧化物、磁性氧化物、碳纳米管等)在重金属离子分离富集中的应用研究(引用文献63篇)。     

PMBP缩2-萘胺席夫碱及其铜(Ⅱ)配合物的合成与抑菌活性

合成了1-苯基-3-甲基-4-苯甲酰基-吡唑啉酮-5(PMBP)缩2-萘胺席夫碱(HL)及其铜(Ⅱ)配合物,由元素分析、络合滴定法、质谱和摩尔电导值确定配合物的组成为[CuL2],通过核磁共振氢谱、红外光谱、热重谱和液相色谱-质谱联用技术对配体和配合物的结构进行了表征,同时还对目标化合物的抑菌活性进行了初步考察。结果表明:配体和配合物对受试的4个菌种均有不同程度的抑菌活性,抑菌能力配合物强于配体,呈现浓度效应,在浓度为3.0 mg.mL-1时最大直径可达14.9 mm。     

Synthesis and characterization of Cd1−xZnxS nanopowder and its nanostructured thin films

The effect of the current on the pinching process of Xe plasma columns pumped by capillary discharge has been studied theoretically and experimentally. An extreme ultraviolet emission monitor (E-Mon, 13.5 nm in 2% bandwidth) was applied to record the temporal evolution of the 13.5 nm (2% bandwidth) emission. According to real current waveforms, the pinching processes were simulated with the snow-plow model. Both the experimental and the simulation results showed that intensity of the 13.5 nm emission reached the maximum when the plasma was pinched to the minimum radius. The E-Mon signals and the simulations indicated that under different amplitudes of the currents the plasma could be pinched more times and faster with higher discharge current.