35MeV/u 40 Ar+197 Au反应中热核的碎裂密度

许多提取核反应过程中熵产生的方法只适用于高能核反应过程 ,而约化d的产额方法可以用于较低能量的重离子核反应中 .对于 3 5MeV/u40 Ar+ 197Au的核反应过程 ,利用这种方法所得的熵和约化带电粒子多重性提取的熵结果一致 .对于后角热核发射体系 ,实验提取的核温度为 ( 4.7± 1 .2 )MeV ,熵为S/A =2 .5± 0 .5,根据实验提取的熵和核温度可以确定其碎裂密度小于 0 .1 ρ0     

10 ps High Power Laser System at 248 nm

A simple 10 ps KrF laser system consisting of quenched dye laser oscillator pumped by a XeCl laser, a distributed feedback dye laser (DFDL), a three-stage dye amplifier and a two-stage KrF amplifier are described. The output of the laser system is 140 mJ with 10 ps pulse width by using polarization-multiplexing amplification. A focused output laser intensity of about 4×1015 W/cm2 is obtained. The saturation fluence for KrF laser is obtained with this laser.     

光波导三向力触觉传感技术及信号处理

本文阐述了一种新的光波导型三向力触觉传感器的工作原理和基本结构,并设计了实验系统。这种传感器由一个橡胶垫和一个光波导路等组成,在橡胶垫的一侧制作圆柱触头阵列,在其另一侧制作圆锥触头阵列,使得每个圆柱触头下面分布2×2个圆锥触头。圆柱触头与施力的物体接触,而圆锥触头与光波导板接触。施加到圆柱触头上的力的三个分量可以通过该圆柱触头所对应的2×2个圆锥触头与光波导板接触时溢出的光斑面积确定。通过CCD摄取此光斑送入计算机进行图象处理,从而可求出光斑面积大小。实验结果显示了力的三个分量能通过圆锥触头的四个接触面积求出。     

差分光学吸收光谱(DOAS)技术在烟气SO2监测中的应用

本文将差分光学吸收光谱(Differential Optical Absorption Spectroscopy,DOAS)技术中的浓度反演方法运用到烟气SO₂监测中.利用SO₂分子在300nm附近具有强吸收的特性,测量出烟气SO₂的吸收光谱,用DOAS方法反演出SO₂分子的浓度,消除了烟气中烟尘、水汽和其它成分的影响,使在线实时测量成为可能,在实验室内对几种SO₂分子浓度样气进行了测量和浓度反演.     

用于高分辨率 PET探测器的LSO闪烁晶体的研究

LSO晶体具有密度大光输出量强和衰减时间短的特性使其成为在PET探测器领域的应用潜在的闪烁晶体材料.按照辐射成象系统应用的性能要求我们对LSO晶体的闪烁特性进行了评价.为了获取较高的光输出量,研究和验证了许许多多的晶体表面的状况对光输出量的影响.对于单个LSO晶体和R5900-00-C12位敏管相耦合的系统,钠伽马射线源的511keV的能量峰处的能量分辨率为15%,时间分辨率为0.65ns,最后对三个LSO阵列分别成象验证了其空间分辨本领.     

牙冠表面三维光学测量和重建方法

选取光栅变形条纹直接分析方法,采用自制的牙冠表面形状三维测量仪和精密可调转台获得了上颌中切牙和下颌磨牙牙冠各个面的三维测量数据,将各面数据在UniGraphic软件平台上通过旋转坐标拍的方法实现数据拼合,重建了牙冠表面的三维形态,生成了牙冠实体模型。     

基于PC机的一种多功能声显微镜及可视化技术的研究

近来研制成功了一种基于ＰＣ机、我们称为“ＴＨＳＡＭＭ”型的多功能声显微镜。在ＰＣ机内插入采样率１ＧＳＰＳ的超高速Ａ／Ｄ卡和信号产生和接收卡,利用软件完成信号检测、处理、显示功能。仪器工作频率为１－１００ＭＨｚ;在检测样品时,同时多层显示Ａ、Ｂ、Ｃ扫描结果。根据声学理论、Ｍａｒｃｈｉｎｇ Ｃｕｂｅ等值面抽取方法和ＯｐｅｎＧＬ技术完成了三维数据的可视化处理,显示样品的内部三维结构。该系统已成功应用于多     

Soliton self-frequency shift in a short tapered air-silica microstructure fiber

We report a soliton self-frequency shift of more than 20% of the optical frequency in a tapered air-silica microstructure fiber that exhibits a widely flattened large anomalous dispersion in the near infrared. Remarkably, the large frequency shift was realized in a fiber of length as short as 15 cm, 2 orders of magnitude shorter than those reported previously with similar input pulse duration and pulse energies, owing to the small mode size and the large and uniform dispersion in the tapered fiber. By varying the power of the input pulses, we generated compressed sub-100-fs soliton pulses of ~1-nJ pulse energy tunable from 1.3 to 1.65 mum with greater than 60% conversion efficiency.     

磁流变体流变学特性研究

对所研制的矿物油介质和硅油介质磁流变体样品的零场粘度、磁流变性能、示功及速度特性进行了系统的测试和分析,并对其影响因素进行了详细的讨论。研制的磁流变体零场粘度小于0．5Pas(γ=81s^-1)且具有良好的粘温特性;磁流变体的剪切应力接近和超过70kPa(B＝6000Gs);在智能减振器的应用试验中获得理想的示功特性曲线。     

Diode-pumped Q-switched Nd:GdVO4/KTP green laser formed with a flat–flat resonator

A diode-pumped acousto-optically Q-switched intracavity frequency-doubled Nd:GdVO₄/KTP green laser formed with a flat–flat resonator was demonstrated. 3.05 W of average green output power at pulse repetition frequency (PRF) of 40 kHz was obtained with an optical conversion efficiency of 18.4%, the effective intracavity frequency-doubling efficiency was 57%. At the incident pump power of 15 W, the shortest laser pulse occurred at PRF of 25 kHz with FWHM width of 14 ns, yielding the highest peak power of 7.44 kW; while the largest pulse energy of 0.14 mJ was achieved at PRF of 15 kHz.