中频采样和数字正交器的原理及工程实现

阐述了中频采样和数字正交器的原理，给出了三种新的中频采样和数字正交的工程实现方法，测试后的性能指标完全能满足现代雷达的实际要求。     

DVB-T接收系统调谐器的选用

介绍了DVB-T接收系统中调谐器的原理,主要讨论了DVB-T接收系统的调谐器选用,包括两款典型调谐器的性能对比,以及调谐器的具体应用.     

多功能取暖管理系统

针对目前的取暖系统中所存在的计费方式不合理、浪费能源、用户选择空间小等诸多弊端,介绍一种基于MSP430FW423单片机的多功能取暖管理系统。阐述了利用MSP430FW423内部SCAN IF实现无磁流量检测的基本原理,以及利用其内部比较器构成SLOPE A/D转换器的方法,给出了热量计算的具体公式。本系统采用软硬件结合的方法,不仅实现了热量表所有的全部功能,而且实现了多种可供用户选择的取暖方式,成功地解决了目前取暖系统中的各种问题。     

IF钢压薄滚焊接头断裂机理

研究了ＩＦ钢压薄滚焊接头断裂的机理，结果发现，裂纹首先在熔合底部的熔核区以微孔聚合的方式形成，并向粗晶区扩展，然后裂纹在粗晶区内一沿一定的解理面扩展，最后在部分再结昌区以滑移面分离的方式断裂。     

无间隙原子钢（IF）再结晶规律及退火工艺对成形性的影响

介绍了无间隙原子钢的成分、热轧、冷轧工艺特点,研究了不同微合金元素添加量的IF 钢再结晶行为及对形成性能的影响和由罩式炉退火及镀锌在线退火生产 IF 钢薄板的可行性。     

Novel techniques in high speed modem implementation using programmable DSPs

We present the design and performance of a high speed MSK modem that incorporates digital heterodyne processing. A novel table look-up procedure for direct IF/RF modulation, based on a suitable maximal-length shift register sequence, is described. High performance, linear phase, low-complexity mixing and filtering in the receiver is achieved using multirate IFIR filters, where the shaping filter may possibly beM-th-band. The configuration of the IFIR filters is chosen based on the carrier frequency and the filtering requirements.     

应用AVR单片机实现中频发送功率自环控制

现代卫星通信系统中，为了维持发送的信号强度，在发射端通常都采用将功率监测和基于基准电压设定点的自动增益控制（AGC）技术结合起来的技术。介绍了采用Atmel公司的AVR单片机ATMEGA128L实现中频发送功率自环控制。控制中频（750MHz～1250MHz）发送功率范围为-30dBm～0dBm，可控步长为1dBm。     

Nitriding of steel in potassium nitrate salt bath

A potassium nitrate salt bath has been used for nitriding of interstitial-free steel. The nitriding behavior can be reasonably well described by nitrogen diffusion in iron. Most nitrogen is dissolved interstitially. During nitriding, a slight oxidation of the steel surface also takes place. The nitrided specimen achieves a pronounced solid–solution strengthening.     

Quantitative phase analysis of galvannealed coatings by coulometric stripping

The characterization of different Fe–Zn phases present in a galvannealed coating has been a challenging area of research in recent years. There have been doubts about the validity of the results obtained by electrochemical stripping because the data cannot be used for straightforward phase identification and because quantification needs to take into account the effect of various electrochemical side-reactions. The optimization of the electrochemical stripping method (also known as coulometric dissolution) and its use as a routine analysis method is reported. It is shown that the method allows the determination of the total Fe concentration, and the thickness and composition of the , , and phases. Coulometric data obtained on a large number of TiNb interstitial free (IF) galvannealed samples were compared with the total iron and zinc concentrations determined by ICP-MS. Validation of the results was done by ICP–MS and EPMA. The coulometric method was verified on a large number of industrially produced galvannealed coatings and pilot line simulated galvannealed coatings.     

连退工艺对Nb+B-IF钢显微组织与性能的影响

以Nb+B-IF钢为研究对象,对其连续退火工艺进行了模拟试验,运用光学显微镜和透射电镜分析技术对不同加热速率细晶高强IF钢显微组织进行了研究。结果表明,随着加热速率提高,饼状铁素体数量增多,晶粒尺寸逐渐增大,屈服强度、抗拉强度和r值升高,n值降低,无沉淀析出区体积分数增大,形状更加稳定。