遥操作康复机器人系统的透明性研究

针对遥操作康复机器人系统通信时廷引起系统性能下降问题,通过建立系统的等效电路图,采用阻抗匹配的方法分析了系统在有时延和无时延两种情况下的透明性.仿真实验结果表明该方法的有效性,时延下的系统在保证稳定的基础上实现了良好的透明性.     

聚苯乙烯改性纤维素纳米晶体对聚甲基丙烯酸甲酯热稳定性的增强作用

采用原子转移自由基聚合(SI-ATRP)在纤维素纳米晶体(CNC)表面接枝聚苯乙烯,并利用傅里叶红外光谱(FTIR)、热重分析仪(TGA)对改性前后的纤维素纳米晶体的化学结构和热稳定性进行了研究。测试结果表明,聚苯乙烯可成功地接枝到纤维素纳米晶体的表面; 纤维素纳米晶体的热分解温度由150 ℃上升到220 ℃,改性后纤维素纳米晶体的热稳定性得到提高。采用溶液浇铸法制备聚甲基丙烯酸甲酯/纤维素纳米晶体复合材料(PMMA/CNC),并利用TGA、透光率测试对复合材料热稳定性和透光率进行了研究。结果表明,当温度达到350 ℃时,PMMA/CNC的热分解温度比纯PMMA提高了近150 ℃, CNC的加入量为1%时,复合材料的透光率为89%,接近纯PMMA的透光率(91%)。聚苯乙烯改性纤维素纳米晶体可用于在保持PMMA透明性的前提下更好地改善PMMA复合材料的热稳定性。     

Quantum coherent control of ultrashort laser pulses

The effective photonic control is one of the key issues in photo-physics. Significant advancement in photonic crystals, quantum optics, ultrafast optics as well as micro-nano-optics gives rise to new op-portunities to manipulate the emission and propagation in optical fields, leading to a number of new and interesting discoveries, e.g., ultrashort light pulse storage and efficient energy conversion. This paper reviews the latest research progress in storage, release and energy conversion for ultrashort laser pulses in periodical arrays of absorbing medium. Techniques to fabricate such devices are also presented.     

一种基于非透明度校正的光线投射体绘制算法

针对传统光线投射体绘制算法的非透明度校正不能满足实际应用的要求,提出了一种新的体绘制算法。该算法基于新的采样合成函数,采用非透明度提前截止来判断光线终止。最后,通过gsgl语言编写顶点程序和片段程序对实现了算法。实验结果表明该算法在不同的采样间距下都可以大大改善体绘制的质量和速度。     

含氟二胺合成及其聚酰亚胺薄膜性能研究

为改善聚酰亚胺薄膜的透明性和溶解性,通过Williamson醚化反应较高产率地合成出高纯度的2,2-双[4-(4-氨基-2-三氟甲基苯氧基)苯基]丙烷,该含氟二胺与3,3’,4,4’-联苯四酸二酐(BPDA)在溶剂中缩聚得到聚酰胺酸,热亚胺化得到玻璃化转变温度Tg为350.2℃、在氮气中10%热失重温度为539.8℃、紫外截止波长为390 nm的含氟透明聚酰亚胺,并合成了联苯二酐/二苯醚二胺薄膜BPDA-ODA,通过对两种薄膜热稳定性、透光率、溶解性能的比较发现,在聚酰亚胺分子结构中引入氟原子,在不改变其热稳定性的前提下,可明显改善聚酰亚胺的透明性和溶解性。     

Simple nanofabrication of a superhydrophobic and transparent biomimetic surface

This paper describes a simple fabrication method for creating superhydrophobic and transparent glass surfaces that mimic natural surfaces such as lotus leaves, moth eyes or cicada wings. Nanostructured glass surfaces were created by a combination of colloidal lithography and plasma etching. A colloidal mask was formed simply by the spin coating of the polystyrene beads and with modification of the interparticle distance between the beads. The etching of the glasses was conducted by CF4 plasma. Tower-shaped nanostructures at an aspect ratio of 1：4 were treated using fluoroalkylsilane selfassembled monolayers （SAMs） to obtain the hydrophobic surfaces. The treated glass surfaces showed superhydrophobicity with a water contact angle of around 150° and a hexadecane contact angle of around 110° Furthermore, the nanostructured glass was transparent to visible light.     

Quantum storage of optical signals and coherent manipulation of quantum states based on electromagnetically induced transparency

Electromagnetically induced transparency (EIT) techniques are important tools for the storage of the quantum states of light fields in atomic ensembles and for enhancement of the interaction between photons. In this paper, we briefly summarize the recent experimental studies conducted by our group on enhanced cross-phase modulation based on double EIT effects, the quantum interference of stored dual-channel spin-wave excitations and the coherent manipulation of the spin wave vector for the polarization of photons in a single tripod atomic system. The work presented here has potential application in the developing field of quantum information processing.     

我国财政透明度现状及对策分析——兼论纳税人知情权、参与权和监督权

财政透明度是建立公共财政体系的必然要求。我国的财政透明度进程大致是从上个世纪90年代末开始启动,目前来看虽然已有改观,但是在财政资金筹集以及分配和使用上离国际规范做法尚有较大差距,不但造成财政资金使用效率低下的后果,同时还使纳税人的知情权、参与权和监督权受到侵害。为此,应当在商品零售环节中实行价税分离的标价方法,同时在财政资金分配上应当改革现有预算制度,加强政府信息公开,完善财政资金使用的决策机制,以保障纳税人知情权、参与权和监督权。     

Numerical Simulations of the Transparency of Waterfront Bodies

Measured field data was used to analyze the factors which influence the transparency of the Nei River and to develop a multi-factor correlation for the transparency. A 2-D unsteady model which coupled analyses of the water flow, water quality, suspended sediments, and Chl-a was developed to simulate the changes in the transparency for various conditions. The model was then used to forecast the transparency of the Nei River. The suspended sediment concentration （SSC） was found to be the most important factor influencing the transparency, with high concentrations of CODMn and Chl-a also reducing the transparency to some extent. The transparency model is stable and precise, with relative errors between measured and calculated values of less than 15%. With the environmental scheduling schemes, the Nei River transparency can be significantly improved with a mean transparency in high-water years of 69.3 cm, normal-water years of 70.8 cm, and low-water years of 69.8 cm.     

超冷玻色气体中的电磁感应透明

研究了超冷玻色气体中的电磁感应透明现象.利用平均场理论,考虑处于所有能级的原子被光势阱所囚禁,本文导出了系统的色散关系并计算了在超冷原子气体中传播的慢光的群速.