退火对直流磁控溅射铬膜附着性的影响

为了利用铬膜改善锆的抗腐蚀性，研究了退火对Zr-2基体上制备的直流磁控溅射铬膜附着性的影响，使用扫描电镜（SEM）观察了界面形貌及锆，铬的界面的分布，用X－射线衍射仪（XRD）分析了膜层的组成，用划痕法测定了铬膜的附着，结果表明，锆／铬界面结合良好，边界可见；与现有文献比较，获得的铬膜附着性好――均超过20N；溅射后退火使Zr-Cr界面更像扩散界面，但X－射线衍射结果未发现有界面反应产物；退火提高铬膜与Zr-2基体的附着性约50％，扩散际着附着性增加的主要因素。     

DWT－Based Watermarking Scheme for Digital Images

A watermarking scheme for digital images is introduced. This method is based on discrete wavelet transform and spread spectrum technique. A discrete wavelet transformed binary signature image is expanded by an m-sequence and added to the large wavelet coefficients of a host image with a scale factor. Good balance be-tween transparency and robustness is achieved by the selection of the scale factor. In addition, the spread spec-trum technique is adopted to increase the robustness of this watermarking scheme. The experimental results show that the proposed method is of good performance and robustness for common image operations such as JPEG lossy compression, etc.     

硬X射线调制望远镜(HXMT)能谱标定系统设计

提出了用于硬X射线调制望远镜的能谱标定方案，并进行了原理实验验证，同时讨论了影响能谱标定系统性能的几个因素．     

真空状态下变压器铁心对地绝缘电阻的变化规律

通过测试变压器铁心对地的绝缘电阻及其模型的绝缘电阻，分析了绝缘电阻随真空度变化而变化的机理。总结出了绝线电阻随真空度变化的规律。     

500kV变电所保护小室设计及抗干扰措施

随着计算机软硬件技术、网络技术，通信技术的发展，计算机监控系统在500kV变电所中已广泛应用。在一些工程中，为减少控制电缆，缩减主建筑占地面积，二次设备采用了放至配电装置区的方式。由于弱电设备多，环境电压等级高，电磁干扰强，使许多人对这种方式的安全可靠性提出了疑问。本文着重从干扰源、抗干扰措施及保护小室的设计角度作了分析，对保护小室下放模式的安全可靠性作出肯定，并对小室屏蔽设计提出了一些看法。     

汽车排气污染浓度预测

运用空气质量模式的基本理论，研究汽车尾气排放的扩散规律。选用多种典型空气质量模式，对汽车污染进行计算机模拟。在每一模式下，可对大气稳定度，混合层高度、扩散参数等进行选择计算；并能进行瞬时浓度及长期浓度的预测。设计的程序适用于各种气象务件、各种道路条件、各种车型。     

双BGO晶体能谱测井

Ｃ／Ｏ测井可以利用ＢＧＯ晶体探测效率高的特点，在其探测器部分放置两个探测器，称为双探测Ｃ／Ｏ测井仪，长短源距两个探头所测谱数据进行补偿，有效地去除了井眼条件的影响，提高了测量精度和油水差值，更加有产地分油水层，并有望能在低孔隙度的地层中使用Ｃ／Ｏ测井仪器。     

A novel integrated silicon capacitive microphone-floating electrode“electret” microphone (FEEM)

A novel principle “electret” microphone, i.e., floating electrode electret microphone, is proposed and implemented in this study. Single-chip fabrication and corrugation technique are used in the design and fabrication of the microphone. The floating electrode is encapsulated by highly insulated materials to ensure that there is no electric-leakage passage between the floating electrode and the electrodes of the microphone. Net-free electronic charges (not “bonded” charges as in traditional electret) in the floating electrode can excite the electric field, which is similar to that of the traditional electret. The floating electrode can be easily charged by use of the “hot” electron technique, available using the avalanche breakdown of the p⁺-n junction. Therefore, the electret microphone is rechargeable, which can greatly increase the lifetime of the device. The preamplifier has been on-chip integrated in a junction-field-effect transistor (JFET) source-follower type with resistors by use of ion implantation. Electret charges are banded in a deep potential trap, thus, this microphone can operate at a high temperature (as high as 300°C) and has high stability and reliability. Experiments show that the prototype has a 3-mV/Pa sensitivity and a larger than 21-kHz frequency bandwidth in a 1 mm ×1-mm diaphragm area. Microphone performance can be further improved by optimized process and design. The fabrication is completely integrated-circuit (IC) compatible, hence, the microphone shows promise in integrated acoustic systems     

预烧淬火速度对NiCuZn铁氧体性能的影响

采用传统的氧化物法制备NiCuZn铁氧体,预烧保温后采用了三种不同方式冷却,研究了冷却速度对材料微观结构和磁性能的影响。发现随着冷却速度的加快,可获得更好微观结构、更高起始磁导率、更低损耗、更高烧结密度之低温共烧材料。     

信息安全系统中一种高速随机序列发生器的设计与实现

对原来的真随机序列发生器进行研究和分析，指出存在的主要问题是：序列的输出速度较慢，把小波分析理论用于真随机序列发生器，改变原来的输出方式，设计一种新的高速随机序列发生器，以满足快速发展的信息安全系统的要求．