Slowly moving matter--wave gap soliton propagation in weak random nonlinear potential

We systematically investigate the motion of slowly moving matter--wave gap solitons in a nonlinear potential, produced by the weak random spatial variation of the atomic scattering length. With the weak randomness, we construct an effective-particle theory to study the motion of gap solitons. Based on the effective-particle theory, the effect of the randomness on gap solitons is obtained, and the motion of gap solitons is finally solved. Moreover, the analytic results for the general behaviours of gap soliton motion, such as the ensemble-average speed and the reflection probability depending on the weak randomness are obtained. We find that with the increase of the random strength the ensemble-average speed of gap solitons decreases slowly where the reduction is proportional to the variance of the weak randomness, and the reflection probability becomes larger. The theoretical results are in good agreement with the numerical simulations based on the Gross--Pitaevskii equation.     

加热炉炉管的红外热像监测方法研究

文中所介绍的乃是获奖项目“高温炉管的红外在线监测诊断及评估系统研究”科研成 果的一部分。试验研究结果表明,在进口的如PM350 类焦平面红外热像仪的基础上,合理地选装高温火焰滤片、广角镜头以及红外隔热罩,便可实现通过看火孔对加热炉炉管进行红外热像的在线监测。而通过试验研究所得到的误差修正方法,可以使炉管的红外热像监测结果与接触式的热电偶测试结果相差小于2 %。现场工业试验的结果表明,该方法完全满足了生产装置监测的需要。     

巧用Word绘制有线电视图纸

给Word的工具栏中添加“有线电视”专用绘图工具栏,充分开发Word的图文编辑功能,实现有线电视设备或其他元器件单元图形的即点即输,可非常方便地编辑出图文并茂的有线电视专业文稿。     

Towards a nonperturbative foundation of the dipole picture: II. High energy limit

This is the second of two papers in which we study real and virtual photon-proton scattering in a nonperturbative framework. In the first paper we have identified the leading contributions to this process at high energies and have derived expressions for them which take into account the renormalisation of the photon-quark-antiquark vertex. In the present paper we investigate the approximations and assumptions that are necessary to obtain the dipole model of high energy scattering from the results derived in the first paper. We discuss the gauge invariance of different contributions to the scattering amplitude and point out some subtleties related to gauge invariance in the correct definition of a perturbative photon wave function. As a phenomenological consequence of the dipole picture we derive a bound on the ratio of the cross sections for longitudinally and transversely polarised photons. This bound is independent of any particular model for the dipole-proton cross section and allows one to test the validity of the assumptions leading to the dipole picture in particular at low photon virtualities. We conclude that the naive dipole model formula should be supplemented by two additional terms which can potentially become large at small photon virtualities.     

惯性／DGPS精密进场着陆引导系统

为确保飞机精确直线飞越预定点上空并具备精密进场着陆引导能力 ,研制了机载惯性 /DGPS精密进场着陆引导系统。该系统通过综合技术将惯性导航系统与差分 GPS有效组合 ,不仅定位精度高、工作可靠 ,而且输出信息实时、连续 ;通过着陆引导轨迹及引导画面的精心设计 ,为飞行员提供图形化的、精确安全的进场着陆引导信息 ,引导飞机至决断高处 ,从而解决了飞机全天候尤其是在复杂气象条件的进场着陆引导问题。本文介绍了该系统的方案、组成、系统特点、技术难点以及试飞结果。试飞中飞行员反映该系统精度高 ,引导画面图形直观 ,操作简便 ,能满足复杂气象条件下的进场着陆引导要求     

真空荧光显示器应用的现状及发展

本文综述了真空荧光显示器的应用领域，给出了各类ＶＦＤ的主要技术指标和特点，也介绍了作为打印机光源和象素管的平板荧光器件；并讨论了今后的发展趋势。     

远程实时监视电路系统的设计

介绍了一种远程实时监视系统的接口电路。主要包括视频切换、视频转换及控制电路等部分，配合相应软件可完成多路视频信号的计算机输入及远程图像传输。具有成本低、实用和多功能处理等特点。     

全密封超薄碳纳米管玻璃平板字符显示器件制造工艺的初步探讨

利用自制的场助热丝化学气相沉积设备，在不锈钢电极的部分选取表面上，摸索出了直接生长碳纳米管（CNT’s）勿须涂敷催化剂的新方法。利用得到的高定向多壁碳纳米管薄膜，研究出一种制造大面积实用碳纳米管阵列场发射（CNT’s／FEA）阴极的新方法。经真空条件下的发射特性测量及SEM等检测手段肯定了这种CNT’s／FEA阴极的实用性。从工艺流程角度出发，初步探讨了静态工作制式下，采用碳纳米管做电极后，实现一种全密封超薄碳纳米管玻璃真空字符（或图像）显示器件的可能性。10多只封离管共显示过3种类型的字型（图像），全部管厚仅为2．7mm。实验结果不仅提供了一种碳纳米管阴极在玻璃真空平板型器件内应用的方法，也摸索出了一条实现小尺寸双色（或多色）字符（图像）静态（或动态）显示的廉价、节能途径。     

一种基于频域的视频压缩算法及其实现

提出了一种基于频域的视频编码的方案并描述其如何实现，该算法利用DCT变换和运动图像前后帧在频域的三种状态，对图像快速高效编解码，运算量低，可在PC机上用软件实时实现。     

彩色显像管地磁影响与屏蔽

采用球冠谐和分析方法,首次得到了单个运动电子在全球的受力分布.为减小地磁场对彩色显像管的影响,提高彩色显像管质量,本文提出了一种实用有效屏蔽地磁场的装置.同时,为了能更有效地提高屏蔽效能,提出了将振荡法同磁屏蔽装置一起共同使用的新方案.此外,就屏蔽效果与现行屏蔽方式作了对比分析,证实此装置是有效、可行的.采用该装置,彩色显像管的地磁场裕度可得到大幅度提高,其成果可应用于彩色显像管的生产中,具有降低成本,增进效益的实用价值.