Thinking and Turing's test

The questions raised by A. M. Turing in his paper on thought and machines are discussed. Human thought is considered in turn as a concept of normal language usage, as a basic concept of psychology, and as the basis of intellectual activity. It is concluded that neither of these notions of thought identifies something specific that a human being can or cannot do. The imitation game proposed by Turing for deciding whether a machine can think is found to result from an arbitrary empoverishment of the channel of communication between the interrogator and the item under investigation. Turing's notions of thinking are shown to lead to logical difficulties. An alternative view of consciousness, that would place it beyond the reach of any finite test, is finally discussed.     

Caractérisation et modélisation de composants matriciels infrarougeCharacterization and modelling of IR sensors

The objective of this paper is to describe the first behavioural models of cooled (based on HgCdTe photodetectors) infrared sensors which were designed at CEA-LETI/SLIR. In this way, the interest of such an approach in the evaluation and improvement of optronic systems will be shown. The paper first presents the modelling approach (architecture of the models, choice of parameters, tools for modelling and calibration, …). Then models are compared to measurements on real components in order to verify the efficiency of the modelling approach. To cite this article: P. Castelein, C. R. Physique 4 (2003).     

A novel synthesis of spiro[2.6]nonadienones by the reaction of magnesium cyclopropylidenes with naphtholates and phenolates

The sulfoxide-magnesium exchange reaction of aryl 1-chlorocyclopropyl sulfoxides with i-PrMgCl in THF at low temperature gave magnesium cyclopropylidenes. Treatment of the magnesium cyclopropylidenes with lithium naphtholates or phenolates resulted in the formation of spiro[2.6]nonadienones in up to 82% yield. The structure of the spiro[2.6]nonadienones was found to be dependent on the structure of the naphtholates and phenolates.     

Application of Origen2.1 in the decay photon spectrum calculation of spallation products

Origen2.1 is a widely used computer code for calculating the burnup, decay, and processing of radioactive materials. However, the nuclide library of Origen2.1 is used for existing reactors like pressurized water reactors. To calculate the photon spectrum released by the decay of spallation products, we have made specific libraries for the ADS tungsten spallation target, based on the results given by the FLUKA Monte Carlo code. All the data used to make the Origen2.1 libraries are obtained from Nuclear structure & decay Data (NuDat2.6). The accumulated activity of spallation products and the contribution of nuclides to photon emission are given in this paper.     

2,6-二巯基嘌呤互变异构体热力学稳定性的密度泛函理论研究

利用密度泛函(DFT)B3LYP/6-311G(d,p)方法,水相计算采用自洽反应场(SCRF)中的Onsager模型,对气相和水相中可能存在的13种2,6-二巯基嘌呤互变异构体进行了全优化,并计算了各异构体的热力学参数、偶极矩及原子净电荷。计算结果表明,不论是气相还是水相,二硫酮DTP(1,3,7)是最稳定的异构体。溶剂化效应使各异构体的稳定性均增强,偶极矩大者其稳定性显著增大。溶剂化吉布斯自由能与异构体在两相中偶极矩之差存在相关性。二硫酮DTP(1,3,7)在水相中与致癌物BPDE进行亲核取代反应时,二硫酮DTP(1,3,7)中的S10原子优先进攻亲电试剂BPDE.     

Ultrasound‐Assisted Synthesis of 6‐Methyl‐1,2,3,4‐tetrahydro‐N‐aryl‐2‐oxo/thio‐4‐arylpyrimidine‐5‐carboxamides Catalyzed by Uranyl Nitrate Hexahydrate

An efficient and simple method developed for the synthesis of 6‐methyl‐1,2,3,4‐tetrahydro‐N‐aryl‐2‐oxo/thio‐4‐arylpyrimidine‐5‐carboxamide derivatives ( 4a‐o ) using UO₂(NO₃)₂.6H₂O catalyst under conventional and ultrasonic conditions. The ultrasound irradiation synthesis had shown several advantages such as milder conditions, shorter reaction times and higher yields. The structures of all the newly synthesized compounds have been confirmed by FT‐IR, ¹H NMR, ¹³C NMR and mass spectra.     

Li2.6Co0.4N材料的制备及其锂离子嵌入热力学和动力学研究

在精制氨气气氛中,以纯相氮化锂和金属钴粉为原料,制备了新型锂电池负极材料Li2.6Co0.4N。利用XRD测定了其结构;采用库仑滴定方法对其锂离子的嵌入行为进行研究。结果表明,Li2.6Co0.4N样品具有六方晶系结构,其晶胞参数为a=0.500nm,c=0.387nm;比容量为829mA·h·g-1,锂离子最大嵌入量为1.7215,室温下锂离子化学扩散系数为4.6×10-10～2.65×10-9cm2·s-1,嵌入自由能为-223.98kJ·mol-1,还获得一系列其它热力学和动力学参数。