四种新型仲胺配合物的合成、表征及与ct-DNA相互作用的光谱研究

合成了新型仲胺类配体L(N,N’-二(4-甲基苄基)乙二胺)及其四种过渡金属的硝酸盐配合物,[ML2(H2O)2]2+.2NO3-(M=CuⅡ,CoⅡ,NiⅡ,ZnⅡ),利用元素分析、红外、1H NMR等对其结构进行了表征,其中用X-ray单晶衍射解析了Cu-L单晶结构,为波谱分析推测的分子结构进行了验证。通过紫外、荧光光谱研究了该四种金属配合物与小牛胸腺DNA的相互作用,结果表明配合物与DNA的作用方式均为静电结合,Cu-L,Co-L,Ni-L,Zn-L与DNA的结合常数分别为:1.67×103,2.5×103,1.35×103和9.85×102。     

针板型电晕稳定开关的电晕稳定性

设计了一款可用于触发和自触发的针板型电晕稳定开关,其中针电极直径为2 mm,主间隙距离为10 mm,触发间隙为5 mm。通过静电场的模拟得知其场强的不均匀系数大于7,并且通过大量实验数据得出:开关起晕电压和击穿电压分别为6.8 kV和19.3 kV,由此得知电晕稳定开关的电晕稳定因子为0.55,这说明开关具有较好的电晕稳定性。     

Optical switching based on the manipulation of microparticles in a colloidal liquid using strong scattering force

This paper demonstrates the realization of an optical switch by optically manipulating a large number of polystyrene spheres contained in a capillary.The strong scattering force exerted on polystyrene spheres with a large diameter of 4.3 μm is employed to realize the switching operation.A transparent window is opened for the signal light when the polystyrene spheres originally located at the beam centre are driven out of the beam region by the strong scattering force induced by the control light.The switching dynamics under different incident powers is investigated and compared with that observed in the optical switch based on the formation of optical matter.It is found that a large extinction ratio of ～ 30 dB and fast switching-on and switching-off times can be achieved in this type of switch.     

Recent Advances in Spatial Self-Phase Modulation with 2D Materials and its Applications

In recent years, spatial self-phase modulation (SSPM) with two-dimensional (2D) materials has attracted the attention of many researchers as an emerging and ubiquitous nonlinear optical effect. In this review, the state of the art of 2D material-based SSPM is summarized. SSPM measures or tunes the nonlinearity of 2D materials, and it is also an effective approach to study the band structure of 2D materials. Several modified forms of SSPM, such as high-order, white-light-excited, vector field excited, and optically nonlinearly enhanced SSPM are also presented. Subsequently, the physical origin of the SSPM formation mechanism is compared and analyzed. Furthermore, the applications of SSPM with 2D materials, including passive photonic devices, generation of Bessel beams, and identifying the mode of the orbital angular momentum, are listed. Finally, several urgent problems of the SSPM with 2D materials, potential applications, and prospects for future development are presented.     

A modified NaSch model with density-dependent randomization for traffic flow

Based on the Nagel-Schreckenberg (NaSch) model of traffic flow, a modified cellular automaton (CA) traffic model with the density-dependent randomization (abbreviated as the DDR model) is proposed to simulate traffic flow. The fundamental diagram obtained by simulation shows the ability of this modified NaSch model to capture the essential features of traffic flow, e.g., synchronized flow, metastable state, hysteresis and phase separation at higher densities. Comparisons are made between this DDR model and the NaSch model, also between this DDR model and the VDR model. And the underlying mechanism is analyzed. All these results indicate that the presented model is reasonable and more realistic.     

Influence of nonlinear dispersion on modulation instability of coherent and partially coherent ultrashort pulses in metamaterials

The combination of dispersive magnetic permeability with nonlinear polarization leads to a series of nonlinear dispersion terms in the propagation equations for ultrashort pulses in metamaterials. Here we present an investigation of modulation instability (MI) of both coherent and partially coherent ultrashort pulses in metamaterials to identify the role of nonlinear dispersion in pulse propagation. The Wigner–Moyal equation for partially coherent ultrashort pulses and the nonlinear dispersion relation for MI in metamaterials are derived. Combining the standard MI theory with the unique properties of the metamaterial, the influence of the controllable first-order nonlinear dispersion, namely self-steepening, and the second-order nonlinear dispersion on both coherent and partially coherent MI, in both negative-index and positive-index regions of the metamaterial for all physically possible cases is analyzed in detail. For the first time to our knowledge, we demonstrate that the role of the second-order nonlinear dispersion in MI is equivalent to that of group-velocity dispersion (GVD) to some extent, and thus due to the role of the second-order nonlinear dispersion, MI may appear in the otherwise impossible cases, such as in the normal GVD regime. PACS 42.25.Kb; 42.65.Sf; 78.20.Ci     

Theoretical analysis of a simple yet efficient portable magnetic separator design for separation of magnetic nano/micro-carriers from human blood flow

A technology that could physically remove substances from the blood such as biological, chemical, or radiological toxins could dramatically improve treatment of disease. One method in development proposes to use magnetic-polymer spheres to selectively bind toxins and remove them by magnetic filtration. Although magnetic filtration is a developed technology, the clinical boundary conditions described here require a new filter design. We investigated the removal of toxin-bound magnetic carriers from the blood stream using 2-D FEMLAB simulations. The magnetic separator consisted of a permanent magnet with parallel ferromagnetic prisms on the faces and in contact with a straight tube carrying the magnetic-polymer spheres in suspension. We varied the following parameters: blood flow velocity, the size, and number of ferromagnetic prisms, and the ferromagnetic material in both prisms and magnets. The capture efficiency reached maximum values when the depth of the prisms equaled the diameter of the tubing and the saturation magnetization of the prism material equaled twice that of the magnet. With this design a piece of 2 mm (diameter) tube carrying the fluid resulted in 95% capture of 2.0 μm magnetic-polymer spheres at 10 cm/s flow velocity.     

亲水性材料固相萃取-紫外导数光谱法检测血中茚满二酮类抗凝血杀鼠剂

本文报导了血中茚满二酮类抗凝血杀鼠剂敌鼠、氯敌鼠、杀鼠酮的亲水性材料固相萃取-紫外导数光谱检测法.血样用pH5缓冲液等体积稀释后加于西雷脱硅藻土柱上,柱用乙酸乙酯洗脱,将洗脱液挥发干净,剩余物用pH10缓冲液溶解,测定所得溶液的二阶导数光谱进行定性和定量分析.三种杀鼠剂以10mg/L的量加于空白血中测得萃取率为85%以上,血中三种杀鼠剂的检出限低于2mg/L.萃取中亲水性硅藻土可用硅胶和氧化铝代替,结果相似.     

Analytic investigation on the similariton transmission control in the dispersion decreasing fiber

By means of the similarity transformation, we discuss the generalized nonlinear Schrödinger equation exhibiting inhomogeneous dispersion, nonlinearity and gain or loss at the same time. Explicit bright and dark multi-similariton solutions are obtained. Based on them, we investigate transmission control using the dispersion decreasing fiber with potential applications to the design of high-speed optical devices and amplifiers and pulse compressors, and the development of tunable sources of amplitude modulated light.     

用迈克耳逊干涉仪观察多种不同形式空气劈尖形成的牛顿环

本通过将迈克耳逊干涉仪两臂上的平面镜分别用凹面镜和凸面镜代换,可观察不同形式的空气劈尖形成的牛顿环,对动镜移动时干涉条纹的变化规律作了观察、分析和讨论,此改进后的装置可用于测量曲面镜曲率半径和比较两曲面镜曲率半径的大小。