超声频谱固井质量检测系统下井仪模拟器的设计

给出了直接存储模式曲线的２ＰＳＫ信号的新方法，根据该方法设计了下井仪模拟器，并采用软件调相予以实现。该方法消除了传统相位选择法所存在的倒π现象，提高了系统工作的稳定性和可靠性，同时简化了电路，降低了设备成本。     

诊断专家系统的不确定性问题研究

通过对诊断专家系统的不确定性问题分析，给出了一种诊断推理过程中初始证据的不确定性测度方法，以及不确定性推理中规则匹配及置信度传递算法．     

Stability of expression-linked surface antigen gene in Trypanosoma equiperdum

African trypanosomes evade clearance in immune-competent hosts by periodically replacing their major surface glycoprotein with an antigenically different glycoprotein. Expression of many of these variant surface glycoproteins (VSGs) is associated with the duplication and transposition of silent basic copy genes (BCs) into unlinked genomic expression sites. The new expression-linked VSG gene copies (ELCs) are oriented with their 3' ends proximal to chromosome telomeres. Other VSG genes are activated without the production of an ELC. The 3' ends of these VSG genes are near chromosome telomeres both when they are active and when they are inactive. Recently, we have shown that activation of the VSG-1 gene in the BoTaR (Bordeaux trypanozoon antigen repertoire) serodeme of Trypanosoma equiperdum involves the duplication and transposition of a telomeric BC gene into one of at least three unlinked telomeric sites. Here we show that the VSG-1 ELC is inactivated but not eliminated in some antigenic variants derived from a VSG-1 expressor. In addition, a subsequent variant that again expresses VSG-1 has not reactivated the residual VSG-1 ELC (R-ELC), but instead contains a new, active VSG-1 ELC in an unlinked telomeric site. These results show that the simple presence of an ELC in a potential expression site is not sufficient for its expression.     

Viral escape by selection of cytotoxic T cell-resistant virus variants in vivo.

Viruses persist in an immune population, as in the case of influenza, or in an individual, as postulated for human immunodeficiency virus, when they are able to escape existent neutralizing antibody responses by changing their antigens. It is now shown that viruses can in principle escape the immunosurveillance of virus-specific cytotoxic T cells by mutations that alter the relevant T-cell epitope.     

Functions of the colour-opponent and broad-band channels of the visual system

The colour-opponent and broad-band channels of the primate visual system originate in the retina and remain segregated through several neural stations in the visual system. Until now inferences about their function in vision have been based primarily on studies examining single-cell receptive field properties which have shown that the colour-opponent retinal ganglion cells have small receptive fields, produce sustained responses and receive spatially segregated inputs from different cone types; the broad-band cells have large receptive fields, respond transiently and receive cone inputs that are not spatially separated. We have now examined the visual capacities of rhesus monkeys before and after interrupting either of these channels with small lesions at the lateral geniculate nucleus. Here we report that the colour-opponent channel is essential for the processing of colour, texture, fine pattern and fine stereopsis, whereas the broad-band channel is crucial for the perception of fast flicker and motion. Little or no deficits were found in brightness and coarse-shape discrimination, low spatial frequency stereopsis and contrast sensitivity after the disruption of either of the channels.     

Immunocytochemical demonstration of contractile cells in the human ovarian follicle

Actin- and myosin-like immunoreactivity is found in cells located in the theca externa of the follicle wall of the human ovary, and corresponding to previously observed myoid cells. The immunocytochemical observation provides direct structural evidence that non-vascular contractile cells are also present in the follicle wall in humans. As expected, perifollicular blood vessels showed a positive immunoreaction for actin and myosin in their smooth muscle walls.     

Reconfigurable combined forecasts in a non-stationary inflationary environment

This paper presents a composite method for non-stationary economic forecasts, incorporating reconfigurable exponential trend extraction and linear combinations of parabolic and spectral estimators for short-term prediction. The method automatically identifies the points of time series misalignment induced by sharp environmental changes. An application to the problem of hard currency exchange rate prediction in Russia is presented.     

一种用于伺服录写装置的超精密测量、定位系统

给出了一种伺服录写装置定位系统的实现方法，讨论了计算机控制下的超精密测量系统．给出了高数传率的并行十六位接口电路，分析了影响测量精度的因素，研究结果表明，系统测量精度为０．０２μｍ     

一种新的并行排序算法研究

讨论了一种新的并行排序算法．基于前馈阈值神经网络结构，该排序模型利用Ｏ（ｍｎ￣２）个神经元经６个时间步（６级前馈）即可完成排序，排序时间与排序规模无关