黑龙江联通CDMA网络的特点

简要介绍黑龙江联通CDMA的网络结构、建网原则及CDMA 1X网的主要业务。     

HCl氧化物MOS结构质子辐照诱导的界面陷阱效应

用微分电容法研究质子辐照HCl氧化物铝栅MOS结构诱导的界面陷阱,栅氧化层在1 160℃很干燥的、含0～10％HCl的气氛中热生长而成,质子辐照能量为120～300keV,注入总剂量范围为8×10~(13)～1×10~(16)p/cm~2。结果表明,辐照诱导的界面陷阱能级密度随质子能量、剂量增加而增加。然而,氧化层中掺入6％HCl时,辐照诱导的界面陷阱明显减少。这样,已能有效地改变MOS器件的抗辐照性能。实验结果可用H~+二级过程解释。     

ISDN PBX及X.25网关的管理

本文介绍了ＩＳＤＮ用户一网络接口的管理模型，分析了ＰＢＸ、Ｘ．２５网关的管理功能，对协议测试，管理通信进行了研究并提出模型及实现原则。     

任意型一维FIR数字滤波器设计新方法

本文介绍了一种设计任意型（宽带、窄带、低阶、高阶、低通、高通、带通、带阻）一维FIR数字滤波器新方法．给出设计不同类型滤波器的统一方法。各种类型滤波器脉冲响应的设计公式简单、计算方便。该方法消除了Gibbs现象．不仅克服了优化设计中收敛速度、设计精度及初值选取等问题，而且减少设计高阶滤波器的时间。最后，本文给出了各种类型滤波器设计的仿真结果。     

K0.9Li0.1（Ta0.5Nb0.5）O3晶体压电应变系数的测量

用准静态ｄ＿（３３）测量仪和干涉法相结合。测量了Ｋ＿（０．９）Ｌｉ＿（０．１）（Ｔａ＿（０．５）Ｎｂ＿（０．５）Ｎｂ＿（０．５））Ｏ＿３晶体的压电应变系数。结果为：ｄ＿（３３）＝８６．０，ｄ＿（３３）＝一２９．５，ｄ＿（１５）＝１１２．９×１０￣（－１２）Ｃ／Ｎ．     

XIV. Yeast sequencing reports. Sequence of MKT1, needed for propagation of M2 satellite dsRNA of the L-A virus of Saccharomyces cerevisiae

MKT1 is required for m aintenance of K₂ above 30°C in strains with the L-A-HN variant of the L-A double-stranded RNA virus of Saccharomyces cerevisiae. We report that MKT1 encodes a 92 979 Da protein with serine-rich regions and the retroviral protease signature, DTG, but with no substantial homology to proteins presently in the databases. This sequence is available from GenBank under Accession Number U09129.     

Yeast sequencing reports. Isolation and sequence analysis of a gene from the linear DNA plasmid pPAC1–2 of Pichia acaciae that shows similarity to a killer toxin gene of Kluyveromyces lactis

The toxin-encoding linear plasmid systems found in Pichia acaciae and Kluyveromyces lactis yeasts appear to be quite similar, both in function and structural organization. By Southern hybridization, a linear plasmid of P. acaciae, pPac1–2, was found to hybridize to the second open reading frame (ORF2) of K. lactis plasmid pGKL1, known to encode the α and β subunits of the K. lactis toxin. A 1·7 kbp segment of pPac1–2 DNA was cloned, sequenced and shown to contain four regions of strong homology to four similarly oriented regions of K. lactis ORF2. This 1·7 kbp fragment also contained an ORF of 1473 bp that could encode a protein of ～ 55·8 kDa. Like the α subunit gene of K. lactis ORF2, a very hydrophobic region occurs at the N-terminus, perhaps representing a signal sequence for transport out of the cell. Unlike K. lactis ORF2, however, the encoded polypeptide is much smaller and lacks a recognizable domain common to chitinases. The structure of a toxin that includes the translation product of this P. acaciae ORF would likely be quite different from that of the K. lactis toxin. Analysis of the upstream region of the P. acaciae ORF revealed an upstream conserved sequence identical to that found before ORFs 8 and 9 of pGKL2. A possible hairpin loop structure, as has been described for each of the four K. lactis pGKL1 ORFs, was found just upstream of the presumed start codon. The similarity of the promoter-like elements found in the linear plasmid genes of these diverse yeasts reinforces the idea of the existence of a unique, but highly conserved, expression system for these novel plasmids. The sequence has been deposited in the GenBank data library under Accession Number U02596.     

Ti-23Al-14Nb-3V合金氩弧焊接头的显微组织及其力学性能

研究了预热对Ｔｉ－２３Ａｌ－１４Ｎｂ－３Ｖ合金焊接性，特别是对消除氩弧焊冷裂纹的作用以及对接头显微组织和力学性能的影响。结果表明，焊前预热可有效降低该合金的冷裂倾向。经预热处理后，焊缝区的结晶层状线消失，热影响区的硬度峰得到缓和，整个焊缝的显微硬度分布趋于均匀，但焊缝区的枝晶发生粗化，热影响区有所扩大。焊件接头的拉伸试验表明，预热可使焊缝区的接头强度系数增加，但无论预热与否，接头强度均低于母材强度，且不显示宏观塑性。     

Thermomechanical fatigue—damage mechanisms and mechanism-based life prediction methods

An existing extensive database on the isothermal and thermomechanical fatigue behaviour of high-temperature titanium alloy EVII 834 and dispersoid-strengthened aluminum alloy X8019 in SiC particle-reinforced as well as unreinv conditions was used to evaluate both the adaptability of fracture mechanics approaches to TMF and the resulting predictive capabilities of determining material life by crack propagation consideration. Selection of the correct microstructural concepts was emphasised and these concepts were, then adjusted by using data from independent experiments in order to avoid any sort of fitting. It is shown that the cyclic /-integral (δJ_eff concept) is suitable to predict the cyclic lifetime for conditions where the total crack propagation rate is approximately identical to pure fatigue crack growth velocity. In the case that crack propagation is strongly affected by creep, the creep-fatigue damage parameter δ_CF introduced by Riedel can be successfully applied. If environmental effects are very pronounced, the accelerating influence of corrosion on fatigue crack propagation can no longer implicitly be taken into account in the fatigue crack growth law. Instead, a linear combination of the crack growth rate contributions from plain fatigue (determined in vacuum) and from environmental attack is assumed and found to yield a satisfactory prediction, if the relevant corrosion process is taken into account.