光磁共振实验中壁弛豫过程与外磁场的关系

利用改进后的DH807型光磁共振实验装置,在静态磁场下精确测量了抽运信号的弛豫饱和值与外磁场的关系,从而得到壁弛豫速率与外磁场的关系,并建立模型对其原理进行了探讨.     

Application of the photon's intrinsic flux to the 1s‐2p and 2p‐3d excitonic transitions in nanostructures

We have applied our two recent results [depending on its helicity photon carries a quantum flux of ± Φ ₀ = ± hc/e and the quantized magnetic fluxes through the electronic orbits of the Dirac hydrogen atom are given by: Φ (n,l,m_j) = (n‐l‐m_j)Φ₀) ] to the 1s‐2p and 2p‐3d excitonic transitions in nanostructures. It is shown that the flux changes for the non‐zero matrix elements in the 1s‐2p and 2p‐3d excitonic transitions is either ± Φ₀ or zero. The present result supports the previous results stated above. It is also shown that spin flip is possible in the 1s‐2p and 2p‐3d excitonic transitions.     

原位聚合法制备聚酰胺/聚苯胺复合导电纤维

研究了原位聚合法制备聚酰胺/聚苯胺导电纤维,并对制备的复合纤维进行红外及光学显微镜测试,结果表明聚苯胺与纤维成功复合。对制备的复合纤维进行电导率测试,采用控制单一变量法探讨了苯胺单体在不同的条件下聚合对纤维电导率的影响,并讨论了反应温度对聚合过程和电导率的影响,得出最佳的工艺条件为:纤维经30%的甲酸溶液预处理20min,苯胺单体浓度为0.8M,氧化剂过硫酸铵浓度为1M,掺杂酸为盐酸,浓度为0.8M,冰水浴条件,反应时间为4h,得到的聚酰胺/聚苯胺导电纤维的电导率为3.7S/m。     

Investigation of characteristics of electrically-controlled liquid-crystal retarders

We present results of studies of main characteristics of electrically-controlled retarders fabricated on the basis of planar- and twist-oriented liquid crystals (LC). The investigated characteristics are time of switching and the calibration curve of controllable phase incursion. Computer simulation and numerical calculations of the processes of LC director reorientation in an external electric field have been performed. Based on LabView software a special program is constructed for computer control of the shape, frequency, and amplitude of the external voltage applied to LC cell. An experiment has been implemented on realization, with use of this program, of the prescribed phase retardation of an optical beam. Calculated results agree with experimental data.     

显示技术的演进与应用

This paper overviews some display technologies which play main roles on today＇s display market. And new technologies which may be used for tomorrow＇s display technologies have been discussed. New technologies will boost the development of display technologies.     

Synthesis and properties of cationic polyelectrolyte with regioregular polyalkylthiophene backbone and ionic‐liquid like side groups

High‐regioregular poly{3‐[6‐(1‐methylimidazolium‐3‐yl)hexyl]thiophene‐2,5‐diyl bromide}, PMHT‐Br, has been prepared by reaction of high‐regioregular (above 92%) poly[3‐(6‐bromohexyl)thiophene‐2,5‐diyl] with 1‐methylimidazole. PMHT‐Br is soluble in water and water miscible solvents such as methanol, DMSO and shows solvatochromism; λ_max (nm): 423 (H₂O); 435 (MeOH); 452 (DMSO). Increased absorption band broadening observed for aqueous solution as well as NMR spectra in D₂O suggests a micelle‐like structure of PMHT‐Br molecules in these solutions: poly(3‐hexylthiophene) core and 1‐methylimidazolium bromide shell. Despite the disturbing effect of ionic groups, the solid‐state PMHT‐Br shows absorption maximum at 520 nm, the band edge at 660 nm (ca. 1.9 eV), and fluorescence emission with maximum at 635 nm, in a good agreement with the polymer regioregularity. Fluorescence emission maxima: λ_em (nm): 598 (H₂O); 562 (MeOH); 574 (DMSO), occur in a vicinity of corresponding adsorption band edges. Plot of electrical conductivity of PMHT‐Br (measured under the dynamic vacuum conditions, 5 × 10^?5 Pa) versus 1/T shows a break at about 70 °C same as the temperature dependence of λ_max of the solid PMHT‐Br. These breaks indicate an increase in the mobility of polymer segments and ions within PMHT‐Br; however, a thermal analysis did not provide solid evidence for it. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3073–3081, 2010     

Quantum Emulation of Extreme Non‐Equilibrium Phenomena with Trapped Atoms

Ultracold atomic physics experiments offer a nearly ideal context for the investigation of quantum systems far from equilibrium. We describe three related emerging directions of research into extreme non‐equilibrium phenomena in atom traps: quantum emulation of ultrafast atom‐light interactions, coherent phasonic spectroscopy in tunable quasicrystals, and realization of Floquet matter in strongly‐driven lattice systems. We show that all three should enable quantum emulation in parameter regimes inaccessible in solid‐state experiments, facilitating a complementary approach to open problems in non‐equilibrium condensed matter.