片式铝电解电容器的设计与工艺探讨

铝电解电容器的片式化关系着ＳＭＴ技术的进程。片式铝电解电容器设计着眼点在耐焊接热、结构紧凑、性能稳定及长寿命方面。工艺质量控制在铆接、包卷、浸渍、装配、装底座等方面。标准、国产化材料、工艺技术是国内生产片式铝电解电容器尚待解决的问题。     

多用户检测CDMA系统中的功率控制性能及其在系统设计中的应用

我们分析了在瑞利衰落信道下，在天线分集的相干多用户检测器的性能。由于多用户检测器是抗远／近效应的，我们将基于ＳＮＲ的功率控制引入多用户检测器以提高系统的性能。最后，我们给出了在系统设计时，基于ＳＮＲ的功率控制的参数的选取。     

GaAs MESFET欧姆接触可靠性研究进展

报道了ｎ型ＧａＡｓ上欧姆接触的制备及其可靠性，以及基于欧姆接触退经的ＧａＡｓＭＥＳＰＥＴ的失效分析，结果表明，ｎ型ＧａＡｓ上欧姆接触的制备已日趋成熟，接触电阻有所减小，表面形貌及热稳定性方面都得到了很大程度的提高，接触材料也日趋丰富ＧａＡｓＭＥＳＦＥＴ的失效分析方法也有明显改进。     

硅基红外焦平面阵列技术的新进展(Ⅱ)

主要介绍以硅为衬底的ＰｂＳ、ＰｂＳｅ、ＰｂＴｅ、ＰｂＳｎＳｅ、ＨｇＣｄＴｅ、ＩｎＳｂ等红外探测器焦平面阵列的新进展。     

在柔性变焦系统中的压力变焦镜

从理论上和实验上对水冷镜的镜面曲率半径随压力变化的规律作了研究。对压力变形后镜面相对于球面作了波像差分析，分析表明压力变焦镜用于中红外激光系统是合适的     

A STUDY ON THE PSEUDOCOLOR ENCODING DISPLAY OF SOUND HOLOSPECTROGRAM

In this paper, a new pseudocolor method to display sound holospectrogram is proposed and studied. On the picture of such a four-dimensional spectrogram, the horizontal axis refers to time, the vertical axis to frequency, the color to phase, and the brightness to magnitude. An example of display is given by employing the realized system.     

CONVERGENCE PROPERTIES OF HIGHER-ORDER MOMENT AND CUMULANT ESTIMATES

The sample estimates of higher-order statistics are studied. Under certain conditions, the almost sure convergence of the third- and fourth-order moment and cumulant estimates of stationary processes is established. The rate of almost sure convergence is obtained for the sample estimates of third- and fourth-order moment and cumulant. Additionally, it is shown that the third- and fourth-order moment and cumulant estimates are asymptotic normal.     

高可靠镀Ni／Au工艺及其在微波PTFE电路上的应用

介绍了高可靠电镀Ｎｉ／Ａｕ工艺在ＰＴＦＥ微波印制电路上的应用，并分析了氨基磺酸盐镀软镍和亚硫酸盐镀软金工艺的影响因素及提高Ｎｉ／Ａｕ镀层之间附着力的措施。通过实验及应用证明了与直接镀金工艺相比，在软基材ＰＴＦＥ敷铜箔板上镀Ｎｉ／Ａｕ工艺能大大提高微波电路的可焊性，高温稳定性和长期可靠性，并且用其所制作的微波器件的高频性能也优于直接镀金工业。     

Multiple negative-differential-resistance (MNDR) phenomena of ametal-insulator-semiconductor-insulator-metal (MISIM)-like structurewith step-compositioned InxGa1-xAs quantum wells

In this paper, a new multiple negative-differential-resistance (MNDR) device based on a metal-insulator-semiconductor-insulator-metal (MISIM)-like structure with step-compositional In_xGa_1-x As quantum wells has been fabricated and demonstrated. The interesting MNDR phenomena are found in the current-voltage (I-V) characteristics of this device. At room temperature, the triple switching behaviours and quadruple stable operation states are obtained. In addition, the sixfold switching behaviors and a staircase-shaped I-V characteristic are observed at -105°C. A sequential carrier accumulation at InGaAs subwells and the potential lowering process are used to qualitatively explain the interesting MNDR phenomena. From the experimental results, it is shown that the studied device has good potential in multiple-valued logic applications     

Performance of trellis-coded direct-sequence spread spectrum withnoncoherent reception in a fading environment

In this paper, we consider the performance of different coding schemes for direct-sequence spread spectrum (DS-SS) in a nonselective Rician faded channel. The Nordstrom-Robinson (NR) code, a nonlinear code that has a large distance for a given rate combined with a trellis code, is examined. A bound is developed on the error probability for this trellis-coded NR (TCNR) code with noncoherent reception over a frequency-nonselective Rayleigh or Rician fading channel with additive white Gaussian noise (AWGN). This bound is tighter than the standard union bound. Our results indicate that the standard union bound can be significantly different from the more accurate results obtained from the improved union bound. In addition, there is a considerable coding gain at high signal-to-noise ratio (SNR) for the TCNR code over the conventional DS-SS code at the same data rate