智能相机管理系统的设计与实现

针对传统的文本编程效率低下、智能相机只允许本地监视以及监视界面固定等问题,自主研发了一套集图形化编程、任务运行、数据监控等功能于一体的智能相机管理系统;分析了智能相机管理系统在编程、运行与监视过程中的功能需求,并进行系统结构的划分和设计;构建图形化图像处理单元、可视化编程界面以实现图形化编程功能;采用网络通讯方式,实现智能相机配置过程的同步、远程监控以及与其他设备的数据交互;讨论了系统中的数据管理模型;最后,通过应用实例验证该系统在工业生产中的可行性。验证结果表明,该系统能缩短开发时间,降低用户开发成本,并能对生产线上的智能相机进行有效的管理。     

在大学物理实验课程中创新人才培养的研究与实践

为培养创新人才,推进大学物理实验课程的教学改革,探索出一条以多层次实验教学体系为主体、以创新研究型教学模式为手段、以科技竞赛创新基地建设为外延的培养创新人才的新途径,使大学物理实验在培养学生创新能力和综合实践能力方面发挥应有的作用。     

间歇式高速电视CCD视频图像实时存储系统

针对间歇式高速电视系统中CCD数字图像需要实时无压缩存储的需求,提出一种基于SCSI磁盘阵列的视频图像实时采集存储方案.在磁盘存储速度可行性论证测试的基础上,利用软件技术实现图像数据硬盘实时存储,并将存入硬盘的数据流转换为BMP文件格式加以显示.实验验证了该方案的可行性.     

A 7-W diode-pumped Nd:YVO4 cw laser at 1.34 μm

A Nd:YVO₄ laser, end-pumped by a fiber-coupled diode-laser array, generates 7.3 W of output power at 1342 nm, the highest so far reported for this host crystal. The slope efficiency is 40% and the output-beam divergence is close to the diffraction limit. An important point in attaining such results is the choice of crystals with low Nd concentration. Received: 16 July 2002 / Published online: 25 October 2002 RID="*" ID="*"Corresponding author. Fax: +39-050/844333, E-mail: dilieto@df.unipi.it RID="**" ID="**"Permanent address: Scuola Normale Superiore, Piazza dei Cavalieri 7, Pisa, Italy     

Nonlinear Crosstalk Suppression in WDM-SCM Systems

The mechanism of nonlinear crosstalk in WDM-SCM fiber communication systems is investigated. Then the crosstalk suppression method of complementary modulation of twin carriers is introduced and discussed. Aiming at the limitation of this method, a new method named symmetric carrier complementary modulation is presented, and it has shown satisfactory effect in crosstalk reduction.     

Efficient second, third, fourth, and fifth harmonic generation of a Yb-doped fiber amplifier

We report generation of the second, third, fourth, and fifth harmonics of the output of a Yb-doped fiber amplifier seeded by a passively Q-switched Nd:YAG microchip laser. We obtained high conversion efficiencies using a simple optical arrangement and critically phase-matched nonlinear crystals. Starting with 320 mW of average power at 1064 nm (86 μJ per pulse at a 3.7 kHz repetition rate), we generated 160 mW at 532 nm, 38 mW at 355 nm, 69 mW at 266 nm, and 18 mW at 213 nm. The experimental results are in excellent agreement with calculations.     

Giant shot-like voltage noise in high current density Nb–AlOx–Nb superconducting tunnel junctions

The flat voltage noise component of current biased, high-transparency Nb/AlO_x/Nb superconducting tunnel junctions has been investigated at frequencies up to 70 kHz. Several aspects of the analyzed phenomena suggest the presence of current noise effects induced by the discreteness of the charge carriers. At subgap voltages, where excess currents occur, a behavior coherent with a multiple Andreev reflection-assisted transport through the tunnel barrier has been found. However, the measured charge values exceed any theoretical prediction.     

1137 nm长波掺镱光纤激光器的出光实验

分别使用976 nm半导体激光器和1040 nm光纤激光器作为泵浦源,实现了1137 nm长波光纤激光器的出光,输出功率均超过百mW。激光器采用相同的线性腔结构,高反光栅和低反光栅的反射率分别为99.6%和39.7%,增益介质是一段8 m长的掺镱光纤,纤芯直径5 m。当976 nm半导体泵浦功率为912 mW时,1137 nm激光输出功率为182 mW,对应的斜率效率为28.5%;当1040 nm激光功率为1.59 W时,输出的1137 nm激光功率为278 mW,斜率效率约为25%。在此基础上对两种泵浦方式进行了对比分析。     

Structural phase transition due to La substitution in Bi4Ti3O12

The structure of Bi_4?x La _x Ti₃O₁₂ (BLaTx) as a function of La content from x = 0.00 to 1.25 was studied by Raman spectroscopy and X-ray diffraction (XRD). It was observed that the Raman modes evolve discontinuously at about x = 1.00, which indicates a structural phase transition. Specifically, the B _2g and B _3g Raman modes shown evidences to coalesce into E _g modes with increasing La content. The evolution of Raman modes corresponds to the weakening of ferroelectric orthorhombic lattice distortion with increasing La substitution when x ≤ 1.00 and the final transition into the paraelectric tetragonal structure at higher La content. XRD and electrical measurement results confirm this phase transition by the observation that diffraction peaks from (200) and (020) planes of BLaT0.75 coalesce into one peak in BLaT1.25 and by the corresponding disappearance of remanent polarisation. The impact of La substitution on electrical properties of BLaTx is discussed briefly.     

Evidence for a kaon-bound state K(-)pp produced in K(-) absorption reactions at rest

We have searched for a deeply bound kaonic state by using the FINUDA spectrometer installed at the e(+)e(-) collider DAPhiNE. Almost monochromatic K(-)'s produced through the decay of phi(1020) mesons are used to observe K(-) absorption reactions stopped on very thin nuclear targets. Taking this unique advantage, we have succeeded to detect a kaon-bound state K(-)pp through its two-body decay into a Lambda hyperon and a proton. The binding energy and the decay width are determined from the invariant-mass distribution as 115(+6)(-5)(stat)(+3)(-4)(syst) MeV and 67(+14)(-11)(stat)(+2)(-3)(syst) MeV, respectively.