A functional-dependencies-based Bayesian networks learning method and its application in a mobile commerce system.

This paper presents a new method for learning Bayesian networks from functional dependencies (FD) and third normal form (3NF) tables in relational databases. The method sets up a linkage between the theory of relational databases and probabilistic reasoning models, which is interesting and useful especially when data are incomplete and inaccurate. The effectiveness and practicability of the proposed method is demonstrated by its implementation in a mobile commerce system.     

A steering procedure for the fast vertex fitting method

The fast vertex fitting method [P. Billoir and S. Qian, Nucl. Instr. and Meth. A 311 (1992) 139] has been enhanced by a steering procedure which performs the track selection to insure the vertex fitting quality. Meanwhile, a sign error in a formula in the above publication has been corrected.     

四方向上的任意角度扇形数字滤波器的设计

具有任意角度（扇形所围成的角度）和任意方向（扇形所取方向）的扇形数字滤波器在图像数据压缩和地质、地震等方面的数据处理中有着广泛的应用。目前，大多数的工作多集中于水平及垂直方向的９０°扇形数字滤波器的设计，因而有必要研究任意方向上的任意角度的扇形数字滤波器的设计。本文介绍利用ＭｃＣｌｅｌｌａｎ交换法设计具有垂直，水平及±４５°方向上的任意角度的扇形数字滤波器的设计方法，垂直水平方向上的扇形滤波器的设     

3mm波段极近距离雷达

提出一种极近距离雷达概念，并导出其作用距离公式，在此基础上研制出一台３ｍｍ波段极近距离多普勒雷达样机．试验结果表明该雷达结构简单，成本低廉，在作用距离为零点几米至几米范围内可获得较高的定距精度．     

同轴型光电器件的研究开发

本文简要地介绍了武汉电信器件公司正在研究开发的同轴型光电器件，新的器件的工艺与结构特点以及主要技术指标、使用前景。     

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天然气制合成油得到的柴油燃料基本不含硫和芳烃 ,费—托法合成技术的进步已使天然气制合成油(GTL)的生产成本可与 18～ 2 2美元 /桶的原油价格相竞争 ,因而GTL已成为天然气 ,尤其是偏远地区天然气高效利用的一个有前景的途径。GTL技术由合成气生产、费—托合成和产品精制三部分组成。GTL的工艺方案有埃克森公司AGC - 2 1工艺、壳牌公司SMDS工艺、萨索尔公司Synthol工艺、合成油公司工艺等。GTL技术在合成气生产和费托合成方面还出现了一些新的进展。 2 1世纪将迎来GTL装置新的发展期 ,在未来 15年内 ,预计GTL装置生产能力将增加 (45 0 0～ 6 75 0 )× 10 4 t/a。 2 0 0 5年前将有 7套GTL装置投运 ,总能力 880× 10 4 t/a。     

上市公司2001年业绩及前景

介绍了新闻纸、文化用纸有包装用纸上市公司2001年的主要业绩并对其发展前景作了分析。     

金刚石薄膜制备和评价

采用平直钨丝作热解源,并借助钨丝支架的弹性恢复力,较好地解决了热丝热解化学气相沉积法(HFCVD)合成金刚石过程中热解丝的变形问题.样品独立加热,基片温度、钨丝温度、钨丝与样品基片距离均可独立调节.装置改进后,在Si(100)上合成了面积大约45mm×25mm的比较均匀的金刚石膜.用扫描电子显微镜(SEM)、Raman光谱和X射线衍射仪对制备的金刚石膜进行了分析.     

Comparisons of PWM and one-cycle control for power amplifier with multilevel converter

Based on the concepts of cascade multilevel converters and one-cycle technique, comparisons are conducted to characterize the distortion of the pulsewidth modulation (PWM) and one-cycle control methods that were applied to converters. Simulation results for the different control schemes are obtained in PSIM software initially to see the effect of one-cycle control different from that of PWM control. Through the comparisons, the advantages and disadvantages are identified for each method. The one-cycle scheme is better than PWM control in reducing undesirable harmonics and tracing dynamic waveforms. Simulation and experimental results are also provided to verify the conclusions.     

Effect of quercetin on chemiluminescence of human platelets induced by arachidonic acid

Arachidonic acid (AA)-induced platelet chemiluminescence (CL) was measured with a lumiphotometer. Quercetin remarkably inhibited the CL, the IC50 of quercetin was 3 mumol.L-1. When quercetin plus aspirin, which inhibits only cyclooxygenase, was added, the inhibitory rate of platelet-CL obviously increased (P < 0.01). On the other hand, the quercetin had a scavenging effect on superoxide anion radical using alkaline sodium dithionite solution generation. The IC50 was 20.9 mumol.L-1. In addition, superoxide dismutase of 0.1 mg.ml-1 inhibited the platelet-CL by 97.8%, while mannitol, a hydroxyl radical scavenger, only by 43.3% at a concentration of 80 mg.ml-1. These results suggest that the mechanism of the inhibiting AA-induced platelet-CL by quercetin was associated with scavenging the superoxide anion radical directly and with inhibiting the cyclooxygenase.