Nd：MgO：LiNbO3晶体的荧光光谱及其双晶体腔内互倍频实验

采用激光感生荧光技术测量了Ｎｄ：ＭｇＯ：ＬｉＮｂＯ３晶体的偏振荧光光谱，简要地说明了Ｎｄ：ＭｇＯ：ＬｉＮｂＯ３双晶体腔内互倍频的基本原理，并在实验中用染料激光作泵浦源实现了其双晶体腔内互倍频运转；得到５４３ｎｍ横模倍频绿光单端输出约ＹＭＷ，腔前泵浦阈值约３８ＭＷ，总转换效率约为１．３％。     

高频等参数感应(ВИКИЗ)测井技术应用

介绍了高频等参数感应的基本原理。以胜利油田比较典型的 3口井为例 ,详细分析了高频感应资料在划分薄夹层、确定储层流体饱和类型、评价储层电阻率空间分布等方面的应用。研究结果表明 ,高频感应具有极高的纵向分辨率和较好的径向探测特性 ,能够准确计算地层真电阻率、侵入带电阻率及侵入半径 ,通过与常规感应及薄层测井资料的对比 ,论证了高频等参数感应在测井技术应用上的优越性     

Growth condition of iodine-doped n+-CdTe layers in metal-organic vapor phase epitaxy

Iodine doping of CdTe layers grown on (100) GaAs by metal-organic vapor phase epitaxy (MOVPE) was studied using diethyltelluride (DETe) and diisopropyltelluride (DiPTe) as tellurium precursors and ethyliodine (EI) as a dopant. Electron densities of doped layers increased gradually with decreasing the growth temperature from 425°C to 325°C. Doped layers grown with DETe had higher electron densities than those grown with DiPTe. When the hot-wall temperature was increased from 200°C to 250°C at the growth temperature of 325°C, doped layers grown with DETe showed an increase of the electron density from 3.7×10¹⁶ cm⁻³ to 2.6×10¹⁸ cm⁻³. On the other hand, such an increase of the electron density was not observed for layers grown with DiPTe. The mechanisms for different doping properties for DETe and DiPTe were studied on the basis of the growth characteristics for these precursors. Higher thermal stability of DETe than that of DiPTe was considered to cause the difference of doping properties. With increasing the hot-wall temperature from 200°C to 250°C, the effective ratio of Cd to Te species on the growth surface became larger for layers grown with DETe than those grown with DiPTe. This was considered to decrease the compensation of doped iodine and to increase the electron density of layers grown with DETe. The effective ratio of Cd to Te species on the growth surface also increased with decreasing growth temperature. This was considered to increase the electron density with decreasing growth temperature.     

储层横向相变对剩余油分布的影响

处在构造边部、低部位的商５－５井，在改注水井排液中发现不含水的高产这种非常规现象，由此引起对地质因素的分析。浅湖相沉积的主体是滩砂微相，它可细分为“滩脊”和“滩侧”，其中“滩脊”砂体的泥质含量低，孔隙度、渗透率都较高，而“滩侧”则泥质含量高，物性差。在从“滩脊”砂体向“滩侧”过渡时，极易形成类似于砂体尖灭的岩性封堵，造成剩余油富集，而“滩脊”不一定就在构造的高部位。陆相沉积的砂体非均质性很强，孔隙度和渗透率在横向上的变化很大，高部位的油层水淹，低部位的油层不一定就高含水，这是因为砂体横向上的非均质性，使同一时间单元沉积的砂体很可能不连通。基于这些分析，地质工作者不妨运用沉积微相的原理在构造的低部位或边部寻找剩余油富集区，商５－５井的现实给了我们很好的启示。     

IC—V100电台锁相环频率合成器

本文从频率合成器的结构、功能入手,详细阐述了频率编程的原理及方法。     

低相噪,低杂波数字锁相环路滤波器的设计

较详细地分析数字锁相频率合成器的相位噪声，着重用控制论方法对低相噪、低杂波锁相环的环路滤波器进行设计，并用某Ｓ波段频率合成器的实验结果进行了验证。     

Analysis and optimisation of the HIPERLAN Channel Access Contention Scheme

This paper analyses the HIPERLAN channel access mechanism. Both a purely mathematical and a simulation model are built in order to evaluate the two successive phases of the contention scheme. Several optimisations, based on the choice of parametric values, are proposed, evaluated and compared.     

A Method of Combined SHPB Technique and BP Neural Network to Study Impact Response of Materials

Abstract:  A new method combining the split Hopkinson pressure bar (SHPB) technique with the back-propagation (BP) neural network program is proposed. By this method, the treated strain wave signals become smooth with less noises induced by the transverse inertia. Moreover, the dynamic rate-dependent constitutive behaviour of materials can be identified, without any pre-assumption of a constitutive model. It is found that by taking the experimentally measured data of strain, strain rate and time as 'input' and the corresponding data of stress as 'output' of the BP neural network, the dynamic constitutive behaviour with internal damage or phase transformation evolution is easy to be identified, where the time could represent either the internal damage evolution or phase transformation process accompanied with the deformation process. It is emphasised that the data learnt by the BP neural network must include both loading and unloading processes, if the whole loading and unloading response is to be correctly predicted. The comparisons between the predictions and experimental results are in good agreement for both polyamide (PA) polymer (as an example of nonlinear viscoelastic materials) and Ti–Ni alloy (as an example of superelastic materials with stress-induced phase transformation).     

Preparation and characterization of polyurethane microcapsules containing n‐octadecane with styrene‐maleic anhydride as a surfactant by interfacial polycondensation

A series of polyurethane microcapsules containing a phase change material (PCM) of n‐octadecane was successfully synthesized by an interfacial polymerization in aqueous styrene‐maleic anhydride (SMA) dispersion with diethylene triamine (DETA) as a chain extender reacting with toluene‐2,4‐diisocyanate (TDI). The average diameter of microPCMs is in the range of 5–10 μm under the stirring speed of 3000–4000 rpm. Optical and SEM morphologies of microPCMs had ensured that the shell was regularly fabricated with the influence of SMA. FTIR results confirmed that the shell material was polyurethane and the SMA chains associated on core material reacted with TDI forming a part of shell material. The shell thickness was decreasing in the range of 0.31–0.55 μm with the molar ratio of DETA/TDI from 0.84 to 1.35 and the weight of core material increasing from 40 to 80% (wt %). By controlling the weight ratio of PCM as 40, 50, 60, 70, and 80% in microPCMs, it was found using DSC that the T_m and T_c of microPCMs were in the range of 29.8–31.0^oC and 21.1–22.0°C and an obvious phase change had been achieved nearly the same temperature range of that of PCM. The results from release curves of microPCM samples prepared by 1.4, 1.7, and 2.0 g of SMA indicated the release properties were affected by the amount of the dispersant, which attributed to the emulsion effect and shell polymerization structure. The above results suggest that the shell structure of microPCMs can be controlled and the properties of microPCMs determined by shell will perform proper practical usage. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4996–5006, 2006     

高频地波雷达相位补偿系统

OSMAR2000采用的是“一发八收,收发共用”模式的相控阵高频地波雷达.为了扩大其探测的范围,在新的雷达系统中将采用多发多收的模式,从而导致当信号通过通道后,信号的相位会因受到通道的调制而发生改变,使得雷达无法正常工作,因此需要对通道的相位进行实时监控和补偿.在参考了低频段的相位测量原理和射频段的相移电路的设计理论的基础上,该文提出了基于差分放大器、容阻和容感器件的高频地波雷达收发通道的相位控制系统.