基于复数权值神经元的数字逻辑最稳健设计

复数权值神经元由于引入了多阈值逻辑而具有更强的性能,文中根据其数学模型,结合二进神经元稳健性的概念,提出了基于该神经元的稳健性定义.并结合定义,实现了基于单个神经元的基本数字逻辑以及异或运算的最稳健设计方案,从而证明了该稳健神经元实现任意数字逻辑的有效性和可行性,说明了其强大的处理能力.     

Polysaccharide‐based artificial extracellular matrix: Preparation and characterization of three‐dimensional,macroporous chitosan,and heparin composite scaffold

Scaffold‐guided tissue engineering based on synthetic and natural occurring polymers has gained many interests in recent year. In this study, the development of a chitosan‐heparin artificial extracellular matrix (AECM) is reported. Three‐dimensional, macroporous composite AECMs composed of heparin (Hep) and chitosan (Chito) were prepared by an interpolyelectrolyte complex/lyophilization method. The Chito‐Hep composite AECMs were, respectively, crosslinked with glutaraldehyde, as well as cocrosslinked with N,N‐(3‐dimethylaminopropyl)‐N′‐ethyl carbodiimide (EDC/NHS) and N‐hydroxysuccinimide (NHS). The crosslinking reactions were examined by FT‐IR analysis. In physiological buffer solution (PBS), the EDC/NHS‐crosslinked Chito‐Hep composite AECM showed a relative lower water retention ratio than its glutaraldehyde‐crosslinked counterparts. The EDC/NHS‐crosslinked Chito‐Hep composite AECMs showed excellent biocompatibility, according to the results of the in vitro cytotoxic test. This result suggested that the EDC/NHS‐crosslinked Chito‐Hep composite AECMs might be a potential biomaterial for scaffold‐guided tissue engineering applications. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

CO毒化AB5型合金分形特征研究

研究了三种贮氢合金 L a Ni5、L a Ni4 .7Al0 .3、Ml Ni4 .5Al0 .5被 10 0× 10 - 6 CO毒化后的分形特征 ,求出这三种合金在含 10 0× 10 - 6 CO的氢中循环 ,分维分别为 0 .2 5 4 7、0 .170 9、0 .0 72 5。可以较好的解释合金被毒化的宏观现象。     

Variability in the interpretation of thorax radiography in a primary care medical community and its reference radiologists

OBJECTIVE: To know the variability in the interpretation (normal/pathological) of posteroanterior view chest radiograph and the associated factors between a medical primary care community and a Gold Standard (GS) from 3 reference radiologists. DESIGN: Crossover study. SETTING: Primary care. Teaching health centers of Elche. METHODS: Interobserver percentage agreement (IPA) and Kappa statistic (K) were used to analyse the interobserver agreement (IA) between the GS and every of the participants in interpretation of 100 radiographs. Intraobserver variability was assessed with a second review. Using uni and multivariant analysis some possibly associated factors were studied. RESULTS: Overall IPA and K were 71.3% (CI 95%: 69.2-73.3) and 0.41 (CI 95%: 0.36-0.46) respectively. Time employed in radiographs reading and time passed after medicine studies finished were independently and significantly associated to higher and lower interobserver agreement results respectively, whereas recent professional experience, permanent job and age were not associated. Professional training is the variable that most explain the inter and intraobserver variability. CONCLUSIONS: Overall IA is acceptable. The IA showed by the participants trained under the MIR system is good but the IA achieved by the rest of participants is not acceptable. It is necessary a training which increase the clinical competence, as it does MIR training.     

低渗透挥发性油藏注烃类气驱室内实验研究

通过注烃类气驱实验研究，了解文留油田低渗透挥发性油藏注气开发的一般机理和开发特点。采用PVT分析方法分析地层流体的物理性质、注入溶剂的组份；通过细管实验研究地层流体同注入溶剂在130℃时的最小混相压力；长岩心驱替实验分析气驱、水驱、水气交替注气的采收率、压力的变化规律。细管实验研究表明，最小混相压力为47．1MPa，长岩心注天然气驱替实验表现出近混相的特征。天然气驱注气压力低，采收率高，适合于文南油田低渗透挥发性油藏。     

Application of substituted N-arylpyrroles in the corrosion protection of aluminium in hydrochloric acid

The inhibiting action of N-arylpyrroles on aluminium in 0.17 mol dm^–3 hydrochloric acid solution, in the temperature range 20–60 °C, was studied using potentiodynamic and electrochemical impedence spectroscopy techniques. The inhibiting efficiency of both investigated compounds 1-(2-fluorophenyl)-2,5-dimethylpyrrole (compound A) and 1-(2-fluorophenyl)-2,5-dimethylpyrrole-3-carbaldehyde (compound B) slightly increases with increasing temperature of the corrosive solution. Inhibitor adsorption on the elecrode surface decreases the apparent activation energy of the hydrogen evolution reaction. Compound A follows the Temkin adsorption isotherm, while its carbaldehyde derivative follows the Langmuir isotherm. The results of the apparent energy of activation and the standard free energy of adsorption point to stronger chemisorption of the compound A. However, due to additional condensation of molecules with carbaldehyde groups on the electrode surface, the carbaldehyde derivative exhibits even better inhibiting efficiency than compound A. The kinetic corrosion parameters, analysed in terms of the impedance data, show a satisfactory agreement with those obtained by the potentiodynamic method.     

多目标水平井水平段三维设计数学模型

用柱面法推导出多目标水平井水平段三维设计数学模型，并给出了三维设计所需井斜方位角及井斜角的简单计算公式。该数学模型具有一般性，可以方便地编制成计算机程序，对于多目标水平井水平段的优化设计和所有水平井入靶前的随钻修正设计都非常适用。     

真空微电子三极管几何参数的设计考虑

真空微电子三极管是近年来兴起与发展的真空微电子学中的一类重要器件。本文从真空微三极管的工作特性出发,分析了这类器件中所需考虑的几何参数和工作特性的关系,并给出了一些理论和实验公式,为今后的设计提供一些参考。     

Reactive energy measurement using frequency controlled analog-to-pulse-rate converter

Contents This paper analyzes a problem of phase shifting and deseribes a novel method for electronic reactive energy measurement. The proposed measurement structure, composed of an integrator as a phase shifting circuit and a frequency controlled analog-to-pulse-rate converter, provides for the measurement completely in accordance with IEC definition of reactive energy, which is performed with simple but high performance metering device.

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Die Blindverbrauchsmessung anhand eines netzsynchronisierten Analog-Frequenz-Wandlers

Übersicht In diesem Artikel wird das Problem der Phasenverschiebung analysiert und eine neue Meßmethode für elektronische Blindverbrauschsmessung aufgezeigt. Die vorgeschlagene Strucktur, bestehend aus einem Integrator als Phasenschieber und netzkontrolliertem Analog-Frequenz-Wandler, ermöglicht die Verwirklichung eines einfachen aber präzisen Elektrizitätszählers zur Messung der Blindenergie, dessen Arbeitsprinzip mit den IEC Empfehlungen vollkommen übereinstimmt.

     

交流量热法测量SiO2薄膜的热扩散率

介绍了交流量热法测量薄膜热扩散率的原理和系统组建，用脉宽为纳秒级的超短激光脉冲作为热源，测量了Si衬底上厚度为100nm和500nm的SiO2薄膜水平方向上的热扩散率，实验结果表明该结构的热扩散率比SiO2体材料的要小，并且随着SiO2层厚度的减小，热扩散率也减少。