Simultaneous compensation for spatial and temporal dispersion of acousto-optical deflectors for two-dimensional scanning with a single prism

The dispersive nature of the acousto-optical deflector (AOD) presents a challenge to applications of two sequential orthogonal AODs (a two-dimensional AOD) as XY scanners in multiphoton microscopy. Introducing a prism before the two-dimensional (2D) AOD allows both temporal and spatial dispersion to be compensated for simultaneously. A 90 fs laser pulse was broadened to 572 fs without compensation, and 143 fs with compensation. The ratio of long axis to short axis of the exiting laser beam spot was 3.50 without compensation and 1.14 with compensation. The insertion loss was 37%. Two-photon fluorescence microscopy used the compensated 2D AOD scanner to image a fluorescent microsphere, which improves signal intensity -15-fold compared with the uncompensated scanner.     

Long-distance quantum communication with “polarization” maximally entangled states

We propose a scheme for long-distance quantum communication where the elementary entanglement is generated through two-photon interference and quantum swapping is performed through one-photon interference. Local “polarization” maximally entangled states of atomic ensembles are generated by absorbing a single photon from on-demand single-photon sources. This scheme is robust against phase fluctuations in the quantum channels, moreover speeds up long-distance high-fidelity entanglement generation rate.     

Sub- and Super-Luminal Phenomena in a Doubly Driven Four-Level System

With the occurrence of an adding driving field, the properties of the dispersion and the absorption of a four-level system are changed greatly. The system can produce the normal and anomalous dispersion regions with proper parameters. Here, the driving fields can be seemed as knobs to manipulate the groupvelocity of a weak probe field between subluminal and superluminal.     

Phase regulated suppression and enhancement switches of four-wave mixing and fluorescence

We experimentally study the phase regulated switch between elcctromagnctically induced trans- parency and electromagmetically induced absorption in probe transmission signal and the conver- sion between enhancement and suppression in four-wave mixing and fluorescence signals for the first time. By changing the relative phase, electromagnetically induced transparency can be eonverted into electromagnetically induced absorption. In this process, the conversion from suppression to enhancement is also obtained in four-wave mixing and fluorescence signals. This research can be applied in non-linear optical device like optical switch and optical wavelength convertor.     

Constructing a chaotic system with any number of equilibria

In the chaotic Lorenz system, Chen system and Rössler system, their equilibria are unstable and the number of the equilibria are no more than three. This paper shows how to construct some simple chaotic systems that can have any preassigned number of equilibria. First, a chaotic system with no equilibrium is presented and discussed. Then a methodology is presented by adding symmetry to a new chaotic system with only one stable equilibrium, to show that chaotic systems with any preassigned number of equilibria can be generated. By adjusting the only parameter in these systems, one can further control the stability of their equilibria. This result reveals an intrinsic relationship of the global dynamical behaviors with the number and stability of the equilibria of a chaotic system.     

Weighted mean velocity feedback strategy in intelligent two-route traffic systems

Information feedback strategies can influence the traffic efficiency of intelligent traffic systems greatly. Based on the more practical symmetrical two-route scenario with one entrance and one exit, an improved Weighted Mean Velocity Feedback Strategy (WMVFS) is proposed, which is not sensitive to the precision of Global Position System (GPS) devices. The applicability of WMVFS to different weight factors, aggressive probabilities, densities of dynamic vehicles, and different two-route scenarios (symmetrical scenario and asymmetrical scenario with a speed limit bottleneck) is analyzed. Results show that WMVFS achieves the best performance compared with three other information feedback strategies when considering the traffic flux and stability.     

太空单粒子效应光纤陀螺输出地面模拟分析

为了研究在地面环境下模拟分析空间用光纤陀螺输出特性,对光纤陀螺静态高速输出连续相同数据的特性展开了研究。通过对光纤陀螺系统建模,研究了前向增益与两种陀螺输出滤波器的特性。提出了一种计算光纤陀螺静态条件下输出连续相同数据概率的方法。通过理论计算、仿真、实验相结合的研究方法,相互验证了其正确性,发现陀螺输出连续五次相同的概率的量级为10-11,发生的概率极小,为空间应用光纤陀螺系统时钟故障诊断提供了参考。通过研究发现陀螺前向增益越小,越容易导致陀螺输出连续相同的数据;陀螺滤波器对陀螺输出连续相同数据的固有特性有重要的影响;平滑滤波器较FIR滤波器更容易导致输出连续相同的数据。     

应用质量源于设计的理念优化大鼠血浆中大黄蒽醌的分析方法

应用质量源于设计理念建立一种高效液相色谱-荧光检测法(HPLC-FLD)用于测定大鼠血浆中5种大黄蒽醌。用Plackett-Burman设计考察流动相中甲醇含量、pH值、流速、柱温和进样体积对色谱峰的分离度、理论塔板数、最末洗脱峰的保留时间和拖尾因子的影响,结果显示流动相中甲醇含量、流速和柱温对色谱系统的影响显著(p<0.05)。继而采用Box-Behnken设计结合响应面法考察上述三因素对分离度、保留时间和理论塔板数的影响。用Derringer渴求函数评价了响应值的综合作用。得出最优色谱条件为:以甲醇-0.1%(v/v)磷酸水溶液(81.4:18.6, v/v)为流动相等度洗脱,流速1.1 mL/min,柱温31℃,荧光检测激发波长为440 nm,发射波长为540 nm。建立的模型显示良好的预测性。结果表明:质量源于设计的理念可有效地应用于优化高效液相色谱分析方法。     

一种新型双核Cu(Ⅰ)配合物的合成、表征及性质研究

以吡啶-4-甲醛缩4-氨基安替比林和CuCl为原料,采用水热法成功合成出了一个新型双核铜(Ⅰ)的配合物[Cu(L)Cl](L=吡啶-4-甲醛缩4-氨基安替比林),并通过单晶X射线衍射、红外光谱、拉曼光谱、元素分析、热重分析和荧光分析等手段,对该配合物进行表征及性质研究.结果表明:该配合物晶体属于单斜晶系,空间群为P21/c,晶胞参数a =1.3616(4) nm,b =0.68631(19) nm,c =1.9132(5) nm,α=90°,β=106.260(4)°,γ=90°,V=1.7163(8) nm3,Z=4,Dc=1.514 Mg/m3,F(000)=800,μ=1.439 mm-1,R1 =0.0939,ωR2 =0.2363[I＞2σ(I)].     

水相中糖识别人工受体

自然界中,糖类不仅作为生命体系的能量物质和结构物质,而且还作为信息分子在生命过程的细胞识别和调控中扮演着重要的角色,因此对糖识别的研究将极大地有助于糖类参与生理和病理过程的研究。生命体系中糖识别过程一方面基于受体的极性基团与糖羟基的氢键作用,另一方面依靠受体结构中的含芳环非极性基团与糖CH基相互作用,所以在极性溶液水中通过非共价键相互作用实现糖识别过程是当今化学界一个十分吸引人且又极具挑战性的研究课题。人工合成糖识别受体为研究自然界中糖识别过程的基本机制提供了一种有参考价值的模型系统,同时为仿生应用提供了有力的技术支持。本文从超分子化学、多分枝型、合成凝集素类和聚合物界面4种体系论述了近年来非硼酸类人工糖识别受体在水相中识别糖的研究进展及其潜在应用,并且对合成凝集素和界面糖识别体系做了特殊点评,最后对仿生人工合成受体在水相中对糖识别的未来的发展方向做了展望。