Negative Resistance in a Two-Dimensional System with Entropic Barrier

A phenomenon of negative resistance is found in two-dimensional bistable and periodic potentials via Langevin simulation, where output quantities for noise and signal driven system, such as the power-spectrum density modulus and the signal power amplification, can become minima at finite temperatures. In such a system, the curvature of the potential along non-transport degree of freedom at the barrier is larger than that at the local minima. The temperature-dependent effective barrier, i.e. entropic barrier, is introduced via integration over the non-transport variables. The system shows the negative resistance because of the competence between the signal and the entropic barrier.     

驱动场失谐对∧型原子EIT的影响

文章用缀饰原子研究电磁感应透明，为分析探测光强度的破坏性干涉提供了一个清晰的物理图象，用这种方法可更乘法地研究驱动场失谐对电磁感应透明的影响。     

软X光能谱仪探测元件晌应曲线标定

报道了软X光能诺仪探别元件的能量响应曲线标定工作．实验利用北京同步辐射装置-3W1B束经及反射率计靶室，在束流40—80mA、贮存环电子能量2.2GeV专用光运行模式下，在150—1500eV能区的四个能段，做了铝阴极X射线二权管、滤光片及擦入射平面反射镜能量响应标定实验，通过实验数据比对及分析，最终给出X射线二极管在不同能量段最大可能的测量误差范围。     

微液滴的非机械驱动

微液滴的非机械驱动是操纵微小尺雨液体流动的新方法。本文介绍当前有关微液滴非机械驱动的研究进展，包括：利用电化学方法产生并消耗表面活性分子来产生表面张力梯度；把表面浸润性梯度和温度梯度相结合；通过光敏化合物偶氮部分顺反异构的转换导致表面自由能的变化，最后由光照来驱动微液滴，以及利用固体基片上的亲水疏水条纹构建微芯片上实验室的液体非机械输送网络。     

Optical microfiber phase modulator directly driven with low-power light

An optical microfiber phase modulator （OMPM） directly driven with low-power light is presented. Phase modulation response of OMPM is theoretically analyzed. A 10-mm optical microfiber （OM）, tapered from conventional single-mode fiber, is inserted in one arm of a Michelson fiber interferometer. To drive the OMPM, 980-nm wavelength light with sinusoidal intensity modulation is injected into the interferometer. The OMPM response properties are measured and π-phase modulation amplitude can be obtained with only 7.5-mW average power light at 1-kHz modulation frequency. The OMPMs shown in this study have advantages of simple structure, potential compact size, and low-power-driven light.     

索尼LCX029 CRT液晶显示器纯位相调制特性的研究

为了研究索尼LCX029CRT液晶显示器纯位相调制特性,设计了索尼LCX029CRT液晶显示器的驱动电路,并搭建了测试光路对其纯位相调制特性进行了研究,同时对光路进行了理论分析。实验获得一组移动的干涉条纹,实验测试研究结果表明索尼LCX029CRT液晶显示器具有π/2的相位调制特性。     

索尼LCX029CRT液晶显示器纯位相调制特性的研究

为了研究索尼LCX029CRT液晶显示器纯位相调制特性,设计了索尼LCX029CRT液晶显示器的驱动电路,并搭建了测试光路对其纯位相调制特性进行了研究,同时对光路进行了理论分析。实验获得一组移动的干涉条纹,实验测试研究结果表明索尼LCX029CRT液晶显示器具有π／2的相位调制特性。     

Motion of spiral tip driven by local forcing in excitable media

We study the motion of a spiral wave controlled by a local periodic forcing imposed on a region around the spiral tip in an excitable medium. Three types of trajectories of spiral tip are observed： the epicycloid-like meandering, the resonant drift, and the hypocycloid-like meandering. The frequency of the spiral is sensitive to the local periodic forcing. The dependency of spiral frequency on the amplitude and size of local periodic forcing are presented. In addition, we show how the drift speed and direction are adjusted by the amplitude and phase of local periodic forcing, which is consistent with a theoretical analysis based on the weak deformation approximation.     

Numerical simulation of electron cyclotron current drive characteristics on EAST

Electron cyclotron current drive （ECCD） will be applied in the EAST tokamak during its the new campaign. In order to provide theoretical predictions for relevant physical experiments, some numerical simulations of ECCD with the parameters of EAST have been can＇ied out by using TORAY-GA code based on the understanding of ECCD mechanisms. ECCD efficiencies achieved in different plasma and electron cyclotron （EC） wave parameters are given. The dependences of ECCD characteristics on EC wave injection angle, toroidal magnetic field, plasma density, and temperature are presented and discussed.