Stable Narrow Linewidth 689nm Diode Laser for the Second Stage Cooling and Trapping of Strontium Atoms

We report stable narrow linewidth laser systems based on self-developed Littman configuration external cavity diode lasers （ECDLs）. The frequency of the ECDL is stabilized to a high fineness ultralow-expansion glass reference cavity with the Pound-Drever-Hall technique. By heterodyne beating of two identical systems, we conclude that the linewidth 4.3× 10^-14 at an averaging measurement time. of each ECDL is reduced to lower than 150 Hz and its frequency stability reaches time of 1 s, the averaged long-term frequency drift is less than 0.2 Hz/s over 30 h     

Reverse reconciliation for continuous variable quantum key distribution

An efficient and practical post-processing technique based on reverse reconciliation for continuous variable quantum key distribution is proposed and simulated with low-density parity check (LDPC) codes. MultiLevel Coding/ MultiStage Decoding, which fully utilizes optimization technique such as vector quantization and iterative decoding and the optimal channel coding most close to the Shannon limit, was used to realize efficient reverse reconciliation algorithm. Simulation results showed that the proposed m...     

用于测量熔合反应的静电偏转板介绍

An electrostatic deflector for separating the fusion evaporation residues from the beam-like products in heavy ion reactions was installed. The evaporation residue separation and identification with the electrostatic deflector setup was tested with the reaction ^32S＋^96Zr at several energies. The fusion evaporation residues and the beam-like particles were well separated after the electrical separation and the experimental fusion cross section obtained from the angular distribution is in good agreement with the calculated value well above the Coulomb barrier. This confirms the reliability of the setup.     

光谱成像检测法鉴别中药材

使用基于液晶可调谐滤光器的光谱成像检测系统,对西洋参及市面上常用做假冒西洋参的伪品桔梗进行了在体检测.该系统能对检品进行连续光谱成像,光谱分辨率可达0.5 nm,配合使用Matlab软件对图像信号进行处理和分析.获取了400 nm～680 nm之间的连续荧光光谱图像,通过对比西洋参、桔梗的特征光谱曲线,及进行相关系数的计算,有效地区分了西洋参及桔梗.为西洋参的真伪鉴别提供了一定的帮助.     

偏心环形开放台球中粒子逃逸动力学的分形性质

二维台球体系因为能够体现混沌现象的基本特征且数值运算相对简单,从而成为研究微观体系混沌动力学的理想模型,近年来一直广受关注.本文研究非同心的环形开放台球中粒子逃逸的混沌动力学性质,它体现了与初条件密切相关的奇异性.采用简化的盒计数 (box-counting)算法,计算了分形维数,结果定量地反映了粒子逃逸前与环壁碰撞次数随粒子入射角变化的函数关系.其中,特别关注环形台球的偏心率对体系混沌性质的影响.     

First experimental research of the bunch compressor at CAEPLI

Magnetic bunch compressor is one of the key technologies on the path to next generation accelerator driven facilities. In this paper we report the design principles and the first experimental research of the bunch compressor developed at Chinese Academy of Engineering Physics (CAEP). The length of the bunch after compressor is found to be about 0.7 ps (rms) and the peak current exceeds 500 A when operated in the optimized condition. The sensitivity of the bunch length on the phase of the acceleration field and magnetic field of the bunch compressor was also measured and analyzed.     

微波消解-AAS测定柑橘中9种微量元素含量

采用石墨炉和火焰原子吸收光谱法(AAS),测定了温州特产瓯柑和樟橘的果皮、肉汁和外衣中的9种微量元素。结果表明,果皮、果肉汁和外衣中含有丰富的人体必需的微量元素,且外衣和果皮中的微量元素含量高于肉汁中的微量元素含量。这为瓯柑和樟橘药效功能的综合开发利用提供科学依据。     

矿物组分快速定量提取模型及其应用

矿物成分快速鉴定是提高遥感矿产勘探、遥感矿物填图以及诸多地学研究等工作效率的关键。由于技术等各方面的限制,国内外针对矿物快速分析的模型和软件较少。20世纪90年代以来近红外光谱仪在技术上的突破和计算机的发展使得近红外光谱技术在矿物快速识别领域的应用变得可行,先后出现了基于吸收位置的反演模型(模型一)和基于波形匹配的反演模型(模型二)。文章提出了特征光谱线性反演模型。经美国地质调查局矿物光谱库(USGS)端元混合实验数据验证,该模型精度接近100%,远优于模型一和二。对新疆包古图地区地表随机所采23个样本分析,该模型平均精度为64.6%,另外两模型分别为：33.8%和8.1%,优于模型一和二。虽精度尚低于传统镜下鉴定方法,该模型具有高效、方便、工作量小、人为误差小等优点,已初步应用于新疆包古图地区遥感矿产勘探工作,有较好的推广前景。     

Cluster Observation of Eelectrostatic Solitary Waves around Magnetic Null Point in Thin Current Sheet

Electrostatic solitary waves （ESWs） are observed in the vicinity of the magnetic null of the widely studied magnetic reconnection taking place at the near-earth tail when current sheet becomes dramatic thinning during substorm time on 1 October 2001. We use the Imada method for the 2-D reconnection model and study the characteristics of ESWs near the X-line region and the magnetic null points. The result shows that the amplitude of the observed ESWs in the vicinity of X-line region ranges from 0.1mV/m to 5mV/m, and the amplitude is larger near the magnetic null points. The generation mechanism and the role of ESWs associated with magnetic reconnection are also discussed.     

High Power THz Undulator Radiation from Linear Accelerator

A 30-MeV femto-second electron linac is built at the Shanghai Institute of Applied Physics, which can produce high power, coherent THz undulator radiation. We report the experimental facility and measurement of the power, frequency spectrum. First experiments show the averaged power at THz to be about 20mW.