单光子态的产生与测量

报道了通过自发参量下转换产生单光子态的实验研究,使用中心波长425 nm的飞秒脉冲泵浦Ⅰ类非共线相位匹配的BBO晶体,在实验上得到单光子计数率为2.978×10-4,并分析了实验中的相关问题.     

Physical Interpretation of the Motion of a Laser Pulse within the Framework of the Four-Oscillator Model

A physical multidimensional local model of the propagation process of a laser pulse in air having no analogy to famous models in laser physics is constructed. It is based on the representations of classical wave mechanics characteristic of the theory of scalar wave fields.     

Determination of the degree of cure under dynamic and isothermal curing conditions with electrical impedance spectroscopy

This article presents a new methodology for the quantitative determination of the progress of the curing reaction of a thermosetting resin, using the results of electrical impedance spectroscopy. The method is an extension of the use of the imaginary impedance maximum as a reaction progress indicator and is based on the demonstration of a close correlation between the reaction rate, as measured by conventional differential scanning calorimetry, and the rate of change of the value of the imaginary impedance spectrum maximum. Tests on a commercial aerospace epoxy resin under both isothermal and dynamic heating conditions with calorimetry and impedance spectroscopy have demonstrated the validity of the method and set the accuracy limits involved. This technique can be used as a real-time online control tool for thermoset composite manufacturing. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 146–154, 2004     

爆磁压缩发生器通过脉冲变压器对脉冲形成线充电的理论分析

 将爆磁压缩等效为电流源的方法，对爆磁压缩发生器通过脉冲变压器对脉冲形成线充电进行了理论分析，得出爆磁压缩发生器在负载上产生电流波形（简称负载电流）为直线情况和任意电流波形情况下充电电流和充电电压的表达式。分析表明变压器耦合互感与负载电流随时间变化增长率是脉冲形成线充电的两个重要参数，脉冲形成线第一个充电电压峰值与变压器的耦合互感和负载电流波形斜率成正比，负载电流波形斜率的变化可以改变充电电压峰值的时间，斜率不断增加可以延长第一个充电电压峰值时间，从而可能增加充电电压的幅值，提高爆磁压缩发生器能量的利用效率。     

世界上第一个物理技术研究所的建立及其影响

德国夏洛滕堡物理技术研究所（The Physikallisch-Technische Reichanstalt,简称PTR）是世界上第一个国家级的物理技术研究所，它开创了科学研究和技术研究相结合，服务于工业和国家经济之先河。文章从PTR建立的历史背景、早期研究工作和所产生的影响等方面作较为全面的讨论。     

Structural characterization of polypyrrole in the solid state by high resolution 15N NMR spectroscopy [II]

The solid-state ¹⁵N CP/MAS NMR spectra and ¹⁵N spin-lattice relaxation times (T₁) of doped and dedoped ¹⁵N-labeled polypyrroles prepared by electrochemical polymerization, have been measured by means of high-resolution solid-state ¹⁵N NMR. The ¹⁵N signal of polypyrrole consists of four peaks decomposed by line shape analysis. The four peaks obtained have been assigned to the various structures of polypyrrole. Further, the half-width of the ¹⁵N NMR spectra of polypyrroles is discussed as related to the electrical conductivity. © 1995 John Wiley & Sons, Inc.     

镍-酸性铬兰K络合物吸附波

用微分脉冲溶出伏安法研究了镍(11)与酸性铬兰K(ACBK)所生成的络合物在悬汞电极上的电化学特性及电化学反应机理，发现电极反应为镍与酸性铬兰K所生成的络合物吸附在电极表面后发生的不可逆还原。在HCl-硼砂介质中(pH8．67)，络合物在-316mV处有一吸附还原峰，其峰电流与镍浓度在0．001～0．010μ/mL范围内呈现良好的线性关系，其最低检出浓度为0．0005μg／mL。     

High Voltage Pulse Power and the Technics for the Capacitor Power-Storage Type

Lower hybrid wave （LHW）, electro cyclotron （EC） and neutral beam injection （NBI） etc. are the important methods of auxiliary heating. They would be devoted to the HL-2A tokamak step by step. In order to satisfy the debug of each system and the need of the experiment, the system should be equipped with high voltage pulse power （HVPP） according to the requirement.     

Dynamics of Single-Pulse Echo Signals under the Conditions of Zeeman Switching

The signals of a single-pulse echo (SE) generated on nonresonant excitation of an inhomogeneously broadened two-level system by a radio-frequency pulse (RFP), against the background of which a magnetic video pulse (MVP) of certain length has been switched on, have been described analytically. It is established that under the conditions of such excitation several SE signals are formed whose generation moments are determined by the duration and amplitudes of the RFP and MVP. The amplitudes of some of these signals depend on the Rabi frequency according to a quadratic law, and the amplitudes of others depend on this frequency according to a biquadratic law. It has been established that the mechanism underlying the appearance of these signals is associated with zero beats arising as a result of superposition of the magnetization fluctuations at variable frequencies and at a frequency of detuning from resonance. It is shown that in the limiting case, where the RFP duration considerably exceeds the duration of the MVP or is comparable with it, the number of SE signals decreases to two. Theoretical results on the formation of SE and the dependence of the amplitude of these signals on the MVP amplitude agree with the experimental data on NMR pulsed signals in ferromagnetic materials.