The Bell inequalities and the joint measurement of incompatible observables

A quantum-mechanical theory of joint nonideal measurement of incompatible polarization observables is applied to an EPR-like experiment. It is demonstrated that this experiment yields both information satisfying and information violating the Bell inequalities. The measurement is also discussed in the context of a local hidden-variables theory. It is argued that the violation of an additional assumption of reproducibility of the hidden variable rather than violation of locality may be responsible for the violation of the Bell inequalities.     

Applications of micro-analysis to individual environmental particles

An overview is given of the recent applications of micro-analytical techniques to single particle environmental research performed at the University of Antwerp since 1990. Automated electron probe X-ray micro-analysis, laser microprobe mass spectrometry and micro-particle induced X-ray emission are the techniques most used for aerosol, aqueous suspension and sediment characterisation. Other techniques like scanning transmission electron microscopy, electron energy loss spectroscopy, Fourier transform infra red microscopy and secondary ion mass spectrometry have only recently been implemented into environmental research.     

新型多联吡啶的合成

设计并合成了一种新型配体１，２－二（６”－（６－甲基－４’－苯基－２，２’：６’，２”－三联吡啶基）乙烷，它是由１－（６’－甲基－２’－吡啶基）－３－苯基－２－丙烯－１－酮３与１－（６’－甲基－２’－吡啶基）－羰甲基吡啶碘盐４经改良的Ｋｒｏｈｎｋｅ法先制得取代三联吡啶５，然后在氩气流中，－８０℃与ＬＤＡ，氧化剂１，２－二溴乙烷反应，偶联生成新化合物６。３，４，５，６的结构经元素分析，ＩＲ，ＨＮＭＲ     

Excitation of stable transverse wavepackets with quadratic and cubic susceptibilities

We have identified a family of (2+1)D spatial solitary waves which can stably propagate in bulk media in the presence of coexisting diffraction, self-focusing Kerr and quadratic nonlinearities. In a conspicuous range of excitation conditions close to the stationary solutions, the emerging wavepackets are immune to the detrimental occurrence of filamentation and collapse, typical of pure Kerr media. The presence of a second-order contribution to the cubic nonlinear response is, therefore, able to prevent optical damage in applications relying on self-guidance. We show that the cross-phase modulation plays an important effect on stability. Our estimate shows that the effects of the cubic susceptibility cannot be neglected below a certain beam size in realistic crystals (e.g. KTP or similar).