粉尘薄膜爆轰

与普通爆轰不同，粉尘薄膜爆轰波前氧化剂与燃料处于分离状态．由于激波作用下壁面燃料的注入才于壁面附近形成燃烧的粉尘云，燃烧释放的热使激波自持形成粉尘薄膜爆轰。本文在长2、8m，横截面20mm×20mm的方型水平激波管中对此类爆轰进行了实验研究．并根据作者建立的模型对其二维结构进行了数值模拟。     

Multicenter study on the clinical value of fetal pulse oximetry. I. Methodologic evaluation. The French Study Group on Fetal Pulse Oximetry

OBJECTIVE: Our purpose was to evaluate the feasibility of intrapartum fetal pulse oximetry, the distribution of fetal oxygen saturation values, and the relationship with the neonatal outcome in a population with an abnormal fetal heart rate. STUDY DESIGN: A prospective multicenter observational study was performed from June 1994 to November 1995. Fetal oxygen saturation was continuously recorded with use of a Nellcor N-400 fetal pulse oximeter in case of an abnormal fetal heart rate during labor. Simultaneous readings of fetal oxygen saturation and fetal blood analysis were obtained at inclusion and before birth. Feasibility, adverse effects, distribution of fetal oxygen saturation values, and relationship with neonatal outcome were assessed. RESULTS: One hundred seventy-four patients were included. From 172 attempted sensor placements, the procedure was impossible in three cases and fetal oxygen saturation values were obtained in 164 cases (95.3%). Physicians considered sensor placement an easier task than an attempt at fetal blood analysis (easy in 87.5% vs 78.9% for fetal blood analysis, p = 0.03). The mean reliable signal time (+/- SD) was 64.7% +/- 32% during the first stage. There were no serious adverse effects in the study population. The mean fetal oxygen saturation during the first stage of labor was 42.2% +/- 8.0% (10th to 90th percentile range 30% to 53%). Fetal oxygen saturation was significantly correlated with scalp pH (r = 0.29, p = 0.01) but not with neonatal umbilical artery pH or gas values. There was a significant association between low fetal oxygen saturation (< 30%) and poor neonatal condition. CONCLUSION: The feasibility of fetal pulse oximetry is satisfactory in clinical practice. It is easy to use and provides a fair rate of recorded values, even in a population with suspicion of fetal distress. A low fetal oxygen saturation is significantly associated with an abnormal neonatal outcome.     

Selective phosphorylation of adult tau isoforms in mature hippocampal neurons exposed to fibrillar A beta

How senile plaques and neurofibrillary tangles are linked represents a major gap in our understanding of the pathophysiology of Alzheimer's disease. We characterized a hippocampal neuronal culture system in which tau undergoes maturation in vivo; rat neurons maintained in culture for more than 3 weeks replicated the splicing and phosphorylation changes that tau undergoes upon maturation in situ. Using this model system, we induced an Alzheimer-like neuritic dystrophy following the application of fibrillar beta-amyloid. The dystrophy consisted of focal distortions and swellings within the neurites and an altered phosphorylation of the adult tau isoforms. Fibrillar beta-amyloid induced the concomitant activation of MAP kinase and GSK3 beta. The aberrant activation of several signaling pathways may lead to the abnormal phosphorylation of tau and neuritic degeneration.     

活塞综合检测仪的研制

介绍了活塞综合检测仪的功能、组成、检测过程、测量原理与方法和主要技术性能指标。该仪器是国内研制的第一台智能型活塞综合检测仪。实际应用表明,这是一台高精度、高稳定性和高效率的检测仪器。     

简易炉外处理在电炉钢生产中的应用

阐述了小电炉采用投资少，见较快，简单易行的炉外处理措施，提高了钢质量和生产率，生产实践和应用结果表明，本措施可为同类型企业的炼钢工艺完善和技术进步提供参考。     

多信道光纤环形网络结构分析

本文对多信道光纤环形网络结构进行了详细分析，推导出环网内平均路经长度和最大直径计算公式，并分析了最佳多信道光纤环网结构。     

军事卫星通信系统的发展趋势

卫星通信在C~3I系统中将发挥越来越重要的作用,而目前卫星通信又处在一个大发展的时期,可以预计在未来的十年到二十年间卫星通信将面临许多重大变革。论文从四个方面论述了军事卫星通信系统的发展趋势。     

神经网络用于三元分子混合物密度与粘度的预测

以二元系实验为基础，利用反向转播算法训练神经网络，构造混合物组成，温度等与物性关系的模型，用于对４个三元混合物体系（１）邻二甲苯－间二甲苯－对二甲苯；（２）四氯化碳－环己烷－２－丙醇；（３）甲醇－丙酮－水；（４）水－甲醇－乙二醇的密度和５个三元混合物体系（１）信甲苯－间二甲苯－对二甲苯；（２）四氯化碳－环己烷－２－丙醇；（３）氯仿－２－丙醇－２－丁醇；（４）甲醇－丙酮－水；（５）乙醇－甲醇－水的粘     

CNC中插补和轴伺服的微机仿真

本文级出了在ＰＣ机上对一个自己开发ＣＮＣ系统插祉和轴伺服控制进行仿真的结果。它包含按插补原理对直线、圆和渐开线的插补以及对轴伺服控制中的位置环和前馈控制的仿真。轴伺服马达通过一个二阶连续系统模型来仿真，最后得出对伺服进行前馈控制补偿可显著改善系统的输出。     

变井储系数的确定方法及其在反褶积分析中的应用

中针对变井储试井分析问题，给出了确定变井储系数及计算续流量的方法，并用反褶积分析积分析方法解释了未出现径向流的早期测压数据，给出了解决早期试井资料分析问题的有效方法。